only use 1M parameters by default

SMP: Determine initiator by direction instead of role

.git-blame-ignore-revs

@@ -0,0 +1,2 @@
+# Migrate code style to Black
+135df0dcc01ab765f432e19b1a5202d29bd55545

.github/workflows/code-check.yml

@@ -0,0 +1,35 @@
+# Check the code against the formatter and linter
+name: Code format and lint check
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    name: Check Code
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check out from Git
+      uses: actions/checkout@v3
+    - name: Get history and tags for SCM versioning to work
+      run: |
+        git fetch --prune --unshallow
+        git fetch --depth=1 origin +refs/tags/*:refs/tags/*
+    - name: Set up Python
+      uses: actions/setup-python@v3
+      with:
+        python-version: '3.10'
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install ".[build,test,development]"
+    - name: Check
+      run: |
+        invoke project.pre-commit

.github/workflows/python-build-test.yml

@@ -14,6 +14,10 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.8", "3.9", "3.10"]
+      fail-fast: false
 
     steps:
     - name: Check out from Git
@@ -21,19 +25,19 @@ jobs:
     - name: Get history and tags for SCM versioning to work
       run: |
         git fetch --prune --unshallow
-        git fetch --depth=1 origin +refs/tags/*:refs/tags/*      
-    - name: Set up Python 3.10
-      uses: actions/setup-python@v3
+        git fetch --depth=1 origin +refs/tags/*:refs/tags/*
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
       with:
-        python-version: "3.10"
+        python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install ".[test,development,documentation]"
-    - name: Test with pytest
+        python -m pip install ".[build,test,development,documentation]"
+    - name: Test
       run: |
-        pytest
+        invoke test
     - name: Build
       run: |
         inv build
-        inv mkdocs
+        inv build.mkdocs

.gitignore

@@ -3,9 +3,9 @@ build/
 dist/
 *.egg-info/
 *~
-bumble/__pycache__
 docs/mkdocs/site
-tests/__pycache__
 test-results.xml
-bumble/transport/__pycache__
-bumble/profiles/__pycache__
+__pycache__
+# generated by setuptools_scm
+bumble/_version.py
+.vscode/launch.json

.vscode/settings.json

@@ -0,0 +1,80 @@
+{
+    "cSpell.words": [
+        "Abortable",
+        "altsetting",
+        "ansiblue",
+        "ansicyan",
+        "ansigreen",
+        "ansimagenta",
+        "ansired",
+        "ansiyellow",
+        "appendleft",
+        "ASHA",
+        "asyncio",
+        "ATRAC",
+        "avdtp",
+        "bitpool",
+        "bitstruct",
+        "BSCP",
+        "BTPROTO",
+        "CCCD",
+        "cccds",
+        "cmac",
+        "CONNECTIONLESS",
+        "csrcs",
+        "datagram",
+        "DATALINK",
+        "delayreport",
+        "deregisters",
+        "deregistration",
+        "dhkey",
+        "diversifier",
+        "Fitbit",
+        "GATTLINK",
+        "HANDSFREE",
+        "keydown",
+        "keyup",
+        "levelname",
+        "libc",
+        "libusb",
+        "MITM",
+        "NDIS",
+        "NONBLOCK",
+        "NONCONN",
+        "OXIMETER",
+        "popleft",
+        "psms",
+        "pyee",
+        "pyusb",
+        "rfcomm",
+        "ROHC",
+        "rssi",
+        "SEID",
+        "seids",
+        "SERV",
+        "ssrc",
+        "strerror",
+        "subband",
+        "subbands",
+        "subevent",
+        "Subrating",
+        "substates",
+        "tobytes",
+        "tsep",
+        "usbmodem",
+        "vhci",
+        "websockets",
+        "xcursor",
+        "ycursor"
+    ],
+    "[python]": {
+        "editor.rulers": [88]
+    },
+    "python.formatting.provider": "black",
+    "pylint.importStrategy": "useBundled",
+    "python.testing.pytestArgs": [
+        "."
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}

LICENSE

@@ -199,4 +199,23 @@
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
-   limitations under the License.
+   limitations under the License.
+
+
+---
+
+
+Files: bumble/colors.py
+Copyright (c) 2012 Giorgos Verigakis <verigak@gmail.com>
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

README.md

@@ -9,16 +9,16 @@
 Bluetooth Stack for Apps, Emulation, Test and Experimentation
 =============================================================
 
-<img src="docs/mkdocs/src/images/logo_framed.png" alt="drawing" width="200" height="200"/>
+<img src="docs/mkdocs/src/images/logo_framed.png" alt="Logo" width="200" height="200"/>
 
 Bumble is a full-featured Bluetooth stack written entirely in Python. It supports most of the common Bluetooth Low Energy (BLE) and Bluetooth Classic (BR/EDR) protocols and profiles, including GAP, L2CAP, ATT, GATT, SMP, SDP, RFCOMM, HFP, HID and A2DP. The stack can be used with physical radios via HCI over USB, UART, or the Linux VHCI, as well as virtual radios, including the virtual Bluetooth support of the Android emulator.
 
 ## Documentation
 
-Browse the pre-built [Online Documentation](https://google.github.io/bumble/), 
+Browse the pre-built [Online Documentation](https://google.github.io/bumble/),
 or see the documentation source under `docs/mkdocs/src`, or build the static HTML site from the markdown text with:
 ```
-mkdocs build -f docs/mkdocs/mkdocs.yml 
+mkdocs build -f docs/mkdocs/mkdocs.yml
 ```
 
 ## Usage
@@ -29,7 +29,7 @@ For a quick start to using Bumble, see the [Getting Started](docs/mkdocs/src/get
 
 ### Dependencies
 
-To install package dependencies needed to run the bumble examples execute the following commands:
+To install package dependencies needed to run the bumble examples, execute the following commands:
 
 ```
 python -m pip install --upgrade pip
@@ -38,12 +38,20 @@ python -m pip install ".[test,development,documentation]"
 
 ### Examples
 
-Refer to the [Example Documentation](examples/README.md) for details on the included example scripts and how to run them.
+Refer to the [Examples Documentation](examples/README.md) for details on the included example scripts and how to run them.
 
 The complete [list of Examples](/docs/mkdocs/src/examples/index.md), and what they are designed to do is here.
 
 There are also a set of [Apps and Tools](docs/mkdocs/src/apps_and_tools/index.md) that show the utility of Bumble.
 
+### Using Bumble With a USB Dongle
+
+Bumble is easiest to use with a dedicated USB dongle.
+This is because internal Bluetooth interfaces tend to be locked down by the operating system.
+You can use the [usb_probe](/docs/mkdocs/src/apps_and_tools/usb_probe.md) tool (all platforms) or `lsusb` (Linux or macOS) to list the available USB devices on your system.
+
+See the [USB Transport](/docs/mkdocs/src/transports/usb.md) page for details on how to refer to USB devices. Also, if your are on a mac, see [these instructions](docs/mkdocs/src/platforms/macos.md).
+
 ## License
 
 Licensed under the [Apache 2.0](LICENSE) License.

apps/README.md

@@ -47,5 +47,3 @@ NOTE: this assumes you're running a Link Relay on port `10723`.
 
 ## `console.py`
 A simple text-based-ui interactive Bluetooth device with GATT client capabilities.
-
-

apps/controller_info.py

@@ -19,44 +19,103 @@ import asyncio
 import os
 import logging
 import click
-from colors import color
 from bumble.company_ids import COMPANY_IDENTIFIERS
 
+from bumble.colors import color
 from bumble.core import name_or_number
 from bumble.hci import (
     map_null_terminated_utf8_string,
-    HCI_LE_SUPPORTED_FEATURES_NAMES,
     HCI_SUCCESS,
+    HCI_LE_SUPPORTED_FEATURES_NAMES,
     HCI_VERSION_NAMES,
     LMP_VERSION_NAMES,
     HCI_Command,
-    HCI_Read_BD_ADDR_Command,
+    HCI_Command_Complete_Event,
+    HCI_Command_Status_Event,
     HCI_READ_BD_ADDR_COMMAND,
+    HCI_Read_BD_ADDR_Command,
+    HCI_READ_LOCAL_NAME_COMMAND,
     HCI_Read_Local_Name_Command,
-    HCI_READ_LOCAL_NAME_COMMAND
+    HCI_LE_READ_MAXIMUM_DATA_LENGTH_COMMAND,
+    HCI_LE_Read_Maximum_Data_Length_Command,
+    HCI_LE_READ_NUMBER_OF_SUPPORTED_ADVERTISING_SETS_COMMAND,
+    HCI_LE_Read_Number_Of_Supported_Advertising_Sets_Command,
+    HCI_LE_READ_MAXIMUM_ADVERTISING_DATA_LENGTH_COMMAND,
+    HCI_LE_Read_Maximum_Advertising_Data_Length_Command,
 )
 from bumble.host import Host
 from bumble.transport import open_transport_or_link
 
 
+# -----------------------------------------------------------------------------
+def command_succeeded(response):
+    if isinstance(response, HCI_Command_Status_Event):
+        return response.status == HCI_SUCCESS
+    if isinstance(response, HCI_Command_Complete_Event):
+        return response.return_parameters.status == HCI_SUCCESS
+    return False
+
+
 # -----------------------------------------------------------------------------
 async def get_classic_info(host):
     if host.supports_command(HCI_READ_BD_ADDR_COMMAND):
         response = await host.send_command(HCI_Read_BD_ADDR_Command())
-        if response.return_parameters.status == HCI_SUCCESS:
+        if command_succeeded(response):
             print()
-            print(color('Classic Address:', 'yellow'), response.return_parameters.bd_addr)
+            print(
+                color('Classic Address:', 'yellow'), response.return_parameters.bd_addr
+            )
 
     if host.supports_command(HCI_READ_LOCAL_NAME_COMMAND):
         response = await host.send_command(HCI_Read_Local_Name_Command())
-        if response.return_parameters.status == HCI_SUCCESS:
+        if command_succeeded(response):
             print()
-            print(color('Local Name:', 'yellow'), map_null_terminated_utf8_string(response.return_parameters.local_name))
+            print(
+                color('Local Name:', 'yellow'),
+                map_null_terminated_utf8_string(response.return_parameters.local_name),
+            )
 
 
 # -----------------------------------------------------------------------------
 async def get_le_info(host):
     print()
+
+    if host.supports_command(HCI_LE_READ_NUMBER_OF_SUPPORTED_ADVERTISING_SETS_COMMAND):
+        response = await host.send_command(
+            HCI_LE_Read_Number_Of_Supported_Advertising_Sets_Command()
+        )
+        if command_succeeded(response):
+            print(
+                color('LE Number Of Supported Advertising Sets:', 'yellow'),
+                response.return_parameters.num_supported_advertising_sets,
+                '\n',
+            )
+
+    if host.supports_command(HCI_LE_READ_MAXIMUM_ADVERTISING_DATA_LENGTH_COMMAND):
+        response = await host.send_command(
+            HCI_LE_Read_Maximum_Advertising_Data_Length_Command()
+        )
+        if command_succeeded(response):
+            print(
+                color('LE Maximum Advertising Data Length:', 'yellow'),
+                response.return_parameters.max_advertising_data_length,
+                '\n',
+            )
+
+    if host.supports_command(HCI_LE_READ_MAXIMUM_DATA_LENGTH_COMMAND):
+        response = await host.send_command(HCI_LE_Read_Maximum_Data_Length_Command())
+        if command_succeeded(response):
+            print(
+                color('Maximum Data Length:', 'yellow'),
+                (
+                    f'tx:{response.return_parameters.supported_max_tx_octets}/'
+                    f'{response.return_parameters.supported_max_tx_time}, '
+                    f'rx:{response.return_parameters.supported_max_rx_octets}/'
+                    f'{response.return_parameters.supported_max_rx_time}'
+                ),
+                '\n',
+            )
+
     print(color('LE Features:', 'yellow'))
     for feature in host.supported_le_features:
         print('  ', name_or_number(HCI_LE_SUPPORTED_FEATURES_NAMES, feature))
@@ -73,10 +132,19 @@ async def async_main(transport):
 
         # Print version
         print(color('Version:', 'yellow'))
-        print(color('  Manufacturer:  ', 'green'), name_or_number(COMPANY_IDENTIFIERS, host.local_version.company_identifier))
-        print(color('  HCI Version:   ', 'green'), name_or_number(HCI_VERSION_NAMES, host.local_version.hci_version))
+        print(
+            color('  Manufacturer:  ', 'green'),
+            name_or_number(COMPANY_IDENTIFIERS, host.local_version.company_identifier),
+        )
+        print(
+            color('  HCI Version:   ', 'green'),
+            name_or_number(HCI_VERSION_NAMES, host.local_version.hci_version),
+        )
         print(color('  HCI Subversion:', 'green'), host.local_version.hci_subversion)
-        print(color('  LMP Version:   ', 'green'), name_or_number(LMP_VERSION_NAMES, host.local_version.lmp_version))
+        print(
+            color('  LMP Version:   ', 'green'),
+            name_or_number(LMP_VERSION_NAMES, host.local_version.lmp_version),
+        )
         print(color('  LMP Subversion:', 'green'), host.local_version.lmp_subversion)
 
         # Get the Classic info
@@ -96,7 +164,7 @@ async def async_main(transport):
 @click.command()
 @click.argument('transport')
 def main(transport):
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
     asyncio.run(async_main(transport))
 
 

apps/controllers.py

@@ -28,11 +28,14 @@ from bumble.transport import open_transport_or_link
 # -----------------------------------------------------------------------------
 async def async_main():
     if len(sys.argv) != 3:
-        print('Usage: controllers.py <hci-transport-1> <hci-transport-2> [<hci-transport-3> ...]')
+        print(
+            'Usage: controllers.py <hci-transport-1> <hci-transport-2> '
+            '[<hci-transport-3> ...]'
+        )
         print('example: python controllers.py pty:ble1 pty:ble2')
         return
 
-    # Create a loccal link to attach the controllers to
+    # Create a local link to attach the controllers to
     link = LocalLink()
 
     # Create a transport and controller for all requested names
@@ -41,7 +44,12 @@ async def async_main():
     for index, transport_name in enumerate(sys.argv[1:]):
         transport = await open_transport_or_link(transport_name)
         transports.append(transport)
-        controller = Controller(f'C{index}', host_source = transport.source, host_sink = transport.sink, link = link)
+        controller = Controller(
+            f'C{index}',
+            host_source=transport.source,
+            host_sink=transport.sink,
+            link=link,
+        )
         controllers.append(controller)
 
     # Wait until the user interrupts
@@ -54,7 +62,7 @@ async def async_main():
 
 # -----------------------------------------------------------------------------
 def main():
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
     asyncio.run(async_main())
 
 

apps/gatt_dump.py

@@ -19,9 +19,9 @@ import asyncio
 import os
 import logging
 import click
-from colors import color
 
-from bumble.core import ProtocolError, TimeoutError
+import bumble.core
+from bumble.colors import color
 from bumble.device import Device, Peer
 from bumble.gatt import show_services
 from bumble.transport import open_transport_or_link
@@ -49,9 +49,9 @@ async def dump_gatt_db(peer, done):
         try:
             value = await attribute.read_value()
             print(color(f'{value.hex()}', 'green'))
-        except ProtocolError as error:
+        except bumble.core.ProtocolError as error:
             print(color(error, 'red'))
-        except TimeoutError:
+        except bumble.core.TimeoutError:
             print(color('read timeout', 'red'))
 
     if done is not None:
@@ -64,9 +64,13 @@ async def async_main(device_config, encrypt, transport, address_or_name):
 
         # Create a device
         if device_config:
-            device = Device.from_config_file_with_hci(device_config, hci_source, hci_sink)
+            device = Device.from_config_file_with_hci(
+                device_config, hci_source, hci_sink
+            )
         else:
-            device = Device.with_hci('Bumble', 'F0:F1:F2:F3:F4:F5', hci_source, hci_sink)
+            device = Device.with_hci(
+                'Bumble', 'F0:F1:F2:F3:F4:F5', hci_source, hci_sink
+            )
         await device.power_on()
 
         if address_or_name:
@@ -81,7 +85,12 @@ async def async_main(device_config, encrypt, transport, address_or_name):
         else:
             # Wait for a connection
             done = asyncio.get_running_loop().create_future()
-            device.on('connection', lambda connection: asyncio.create_task(dump_gatt_db(Peer(connection), done)))
+            device.on(
+                'connection',
+                lambda connection: asyncio.create_task(
+                    dump_gatt_db(Peer(connection), done)
+                ),
+            )
             await device.start_advertising(auto_restart=True)
 
             print(color('### Waiting for connection...', 'blue'))
@@ -99,7 +108,7 @@ def main(device_config, encrypt, transport, address_or_name):
     Dump the GATT database on a remote device. If ADDRESS_OR_NAME is not specified,
     wait for an incoming connection.
     """
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
     asyncio.run(async_main(device_config, encrypt, transport, address_or_name))
 
 

apps/gg_bridge.py

@@ -17,13 +17,14 @@
 # -----------------------------------------------------------------------------
 import asyncio
 import os
+import struct
 import logging
 import click
-from colors import color
 
+from bumble.colors import color
 from bumble.device import Device, Peer
 from bumble.core import AdvertisingData
-from bumble.gatt import Service, Characteristic
+from bumble.gatt import Service, Characteristic, CharacteristicValue
 from bumble.utils import AsyncRunner
 from bumble.transport import open_transport_or_link
 from bumble.hci import HCI_Constant
@@ -32,24 +33,73 @@ from bumble.hci import HCI_Constant
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
-GG_GATTLINK_SERVICE_UUID                          = 'ABBAFF00-E56A-484C-B832-8B17CF6CBFE8'
-GG_GATTLINK_RX_CHARACTERISTIC_UUID                = 'ABBAFF01-E56A-484C-B832-8B17CF6CBFE8'
-GG_GATTLINK_TX_CHARACTERISTIC_UUID                = 'ABBAFF02-E56A-484C-B832-8B17CF6CBFE8'
-GG_GATTLINK_L2CAP_CHANNEL_PSM_CHARACTERISTIC_UUID = 'ABBAFF03-E56A-484C-B832-8B17CF6CBFE8'
+GG_GATTLINK_SERVICE_UUID = 'ABBAFF00-E56A-484C-B832-8B17CF6CBFE8'
+GG_GATTLINK_RX_CHARACTERISTIC_UUID = 'ABBAFF01-E56A-484C-B832-8B17CF6CBFE8'
+GG_GATTLINK_TX_CHARACTERISTIC_UUID = 'ABBAFF02-E56A-484C-B832-8B17CF6CBFE8'
+GG_GATTLINK_L2CAP_CHANNEL_PSM_CHARACTERISTIC_UUID = (
+    'ABBAFF03-E56A-484C-B832-8B17CF6CBFE8'
+)
 
 GG_PREFERRED_MTU = 256
 
 
 # -----------------------------------------------------------------------------
-class GattlinkHubBridge(Device.Listener):
+class GattlinkL2capEndpoint:
     def __init__(self):
-        self.peer              = None
-        self.rx_socket         = None
-        self.tx_socket         = None
+        self.l2cap_channel = None
+        self.l2cap_packet = b''
+        self.l2cap_packet_size = 0
+
+    # Called when an L2CAP SDU has been received
+    def on_coc_sdu(self, sdu):
+        print(color(f'<<< [L2CAP SDU]: {len(sdu)} bytes', 'cyan'))
+        while len(sdu):
+            if self.l2cap_packet_size == 0:
+                # Expect a new packet
+                self.l2cap_packet_size = sdu[0] + 1
+                sdu = sdu[1:]
+            else:
+                bytes_needed = self.l2cap_packet_size - len(self.l2cap_packet)
+                chunk = min(bytes_needed, len(sdu))
+                self.l2cap_packet += sdu[:chunk]
+                sdu = sdu[chunk:]
+                if len(self.l2cap_packet) == self.l2cap_packet_size:
+                    self.on_l2cap_packet(self.l2cap_packet)
+                    self.l2cap_packet = b''
+                    self.l2cap_packet_size = 0
+
+
+# -----------------------------------------------------------------------------
+class GattlinkHubBridge(GattlinkL2capEndpoint, Device.Listener):
+    def __init__(self, device, peer_address):
+        super().__init__()
+        self.device = device
+        self.peer_address = peer_address
+        self.peer = None
+        self.tx_socket = None
         self.rx_characteristic = None
         self.tx_characteristic = None
+        self.l2cap_psm_characteristic = None
+
+        device.listener = self
+
+    async def start(self):
+        # Connect to the peer
+        print(f'=== Connecting to {self.peer_address}...')
+        await self.device.connect(self.peer_address)
+
+    async def connect_l2cap(self, psm):
+        print(color(f'### Connecting with L2CAP on PSM = {psm}', 'yellow'))
+        try:
+            self.l2cap_channel = await self.peer.connection.open_l2cap_channel(psm)
+            print(color('*** Connected', 'yellow'), self.l2cap_channel)
+            self.l2cap_channel.sink = self.on_coc_sdu
+
+        except Exception as error:
+            print(color(f'!!! Connection failed: {error}', 'red'))
 
     @AsyncRunner.run_in_task()
+    # pylint: disable=invalid-overridden-method
     async def on_connection(self, connection):
         print(f'=== Connected to {connection}')
         self.peer = Peer(connection)
@@ -80,115 +130,221 @@ class GattlinkHubBridge(Device.Listener):
                 self.rx_characteristic = characteristic
             elif characteristic.uuid == GG_GATTLINK_TX_CHARACTERISTIC_UUID:
                 self.tx_characteristic = characteristic
+            elif (
+                characteristic.uuid == GG_GATTLINK_L2CAP_CHANNEL_PSM_CHARACTERISTIC_UUID
+            ):
+                self.l2cap_psm_characteristic = characteristic
         print('RX:', self.rx_characteristic)
         print('TX:', self.tx_characteristic)
+        print('PSM:', self.l2cap_psm_characteristic)
 
-        # Subscribe to TX
-        if self.tx_characteristic:
+        if self.l2cap_psm_characteristic:
+            # Subscribe to and then read the PSM value
+            await self.peer.subscribe(
+                self.l2cap_psm_characteristic, self.on_l2cap_psm_received
+            )
+            psm_bytes = await self.peer.read_value(self.l2cap_psm_characteristic)
+            psm = struct.unpack('<H', psm_bytes)[0]
+            await self.connect_l2cap(psm)
+        elif self.tx_characteristic:
+            # Subscribe to TX
             await self.peer.subscribe(self.tx_characteristic, self.on_tx_received)
             print(color('=== Subscribed to Gattlink TX', 'yellow'))
         else:
-            print(color('!!! Gattlink TX not found', 'red'))
+            print(color('!!! No Gattlink TX or PSM found', 'red'))
 
     def on_connection_failure(self, error):
         print(color(f'!!! Connection failed: {error}'))
 
     def on_disconnection(self, reason):
-        print(color(f'!!! Disconnected from {self.peer}, reason={HCI_Constant.error_name(reason)}', 'red'))
+        print(
+            color(
+                f'!!! Disconnected from {self.peer}, '
+                f'reason={HCI_Constant.error_name(reason)}',
+                'red',
+            )
+        )
         self.tx_characteristic = None
         self.rx_characteristic = None
         self.peer = None
 
+    # Called when an L2CAP packet has been received
+    def on_l2cap_packet(self, packet):
+        print(color(f'<<< [L2CAP PACKET]: {len(packet)} bytes', 'cyan'))
+        print(color('>>> [UDP]', 'magenta'))
+        self.tx_socket.sendto(packet)
+
     # Called by the GATT client when a notification is received
     def on_tx_received(self, value):
-        print(color('>>> TX:', 'magenta'), value.hex())
+        print(color(f'<<< [GATT TX]: {len(value)} bytes', 'cyan'))
         if self.tx_socket:
+            print(color('>>> [UDP]', 'magenta'))
             self.tx_socket.sendto(value)
 
     # Called by asyncio when the UDP socket is created
-    def connection_made(self, transport):
-        pass
-
-    # Called by asyncio when a UDP datagram is received
-    def datagram_received(self, data, address):
-        print(color('<<< RX:', 'magenta'), data.hex())
-
-        # TODO: use a queue instead of creating a task everytime
-        if self.peer and self.rx_characteristic:
-            asyncio.create_task(self.peer.write_value(self.rx_characteristic, data))
-
-
-# -----------------------------------------------------------------------------
-class GattlinkNodeBridge(Device.Listener):
-    def __init__(self):
-        self.peer      = None
-        self.rx_socket = None
-        self.tx_socket = None
+    def on_l2cap_psm_received(self, value):
+        psm = struct.unpack('<H', value)[0]
+        asyncio.create_task(self.connect_l2cap(psm))
 
     # Called by asyncio when the UDP socket is created
     def connection_made(self, transport):
         pass
 
     # Called by asyncio when a UDP datagram is received
-    def datagram_received(self, data, address):
-        print(color('<<< RX:', 'magenta'), data.hex())
+    def datagram_received(self, data, _address):
+        print(color(f'<<< [UDP]: {len(data)} bytes', 'green'))
 
-        # TODO: use a queue instead of creating a task everytime
-        if self.peer and self.rx_characteristic:
+        if self.l2cap_channel:
+            print(color('>>> [L2CAP]', 'yellow'))
+            self.l2cap_channel.write(bytes([len(data) - 1]) + data)
+        elif self.peer and self.rx_characteristic:
+            print(color('>>> [GATT RX]', 'yellow'))
             asyncio.create_task(self.peer.write_value(self.rx_characteristic, data))
 
 
 # -----------------------------------------------------------------------------
-async def run(hci_transport, device_address, send_host, send_port, receive_host, receive_port):
+class GattlinkNodeBridge(GattlinkL2capEndpoint, Device.Listener):
+    def __init__(self, device):
+        super().__init__()
+        self.device = device
+        self.peer = None
+        self.tx_socket = None
+        self.tx_subscriber = None
+        self.rx_characteristic = None
+        self.transport = None
+
+        # Register as a listener
+        device.listener = self
+
+        # Listen for incoming L2CAP CoC connections
+        psm = 0xFB
+        device.register_l2cap_channel_server(0xFB, self.on_coc)
+        print(f'### Listening for CoC connection on PSM {psm}')
+
+        # Setup the Gattlink service
+        self.rx_characteristic = Characteristic(
+            GG_GATTLINK_RX_CHARACTERISTIC_UUID,
+            Characteristic.WRITE_WITHOUT_RESPONSE,
+            Characteristic.WRITEABLE,
+            CharacteristicValue(write=self.on_rx_write),
+        )
+        self.tx_characteristic = Characteristic(
+            GG_GATTLINK_TX_CHARACTERISTIC_UUID,
+            Characteristic.Properties.NOTIFY,
+            Characteristic.READABLE,
+        )
+        self.tx_characteristic.on('subscription', self.on_tx_subscription)
+        self.psm_characteristic = Characteristic(
+            GG_GATTLINK_L2CAP_CHANNEL_PSM_CHARACTERISTIC_UUID,
+            Characteristic.Properties.READ | Characteristic.Properties.NOTIFY,
+            Characteristic.READABLE,
+            bytes([psm, 0]),
+        )
+        gattlink_service = Service(
+            GG_GATTLINK_SERVICE_UUID,
+            [self.rx_characteristic, self.tx_characteristic, self.psm_characteristic],
+        )
+        device.add_services([gattlink_service])
+        device.advertising_data = bytes(
+            AdvertisingData(
+                [
+                    (AdvertisingData.COMPLETE_LOCAL_NAME, bytes('Bumble GG', 'utf-8')),
+                    (
+                        AdvertisingData.INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS,
+                        bytes(
+                            reversed(bytes.fromhex('ABBAFF00E56A484CB8328B17CF6CBFE8'))
+                        ),
+                    ),
+                ]
+            )
+        )
+
+    async def start(self):
+        await self.device.start_advertising()
+
+    # Called by asyncio when the UDP socket is created
+    def connection_made(self, transport):
+        self.transport = transport
+
+    # Called by asyncio when a UDP datagram is received
+    def datagram_received(self, data, _address):
+        print(color(f'<<< [UDP]: {len(data)} bytes', 'green'))
+
+        if self.l2cap_channel:
+            print(color('>>> [L2CAP]', 'yellow'))
+            self.l2cap_channel.write(bytes([len(data) - 1]) + data)
+        elif self.tx_subscriber:
+            print(color('>>> [GATT TX]', 'yellow'))
+            self.tx_characteristic.value = data
+            asyncio.create_task(self.device.notify_subscribers(self.tx_characteristic))
+
+    # Called when a write to the RX characteristic has been received
+    def on_rx_write(self, _connection, data):
+        print(color(f'<<< [GATT RX]: {len(data)} bytes', 'cyan'))
+        print(color('>>> [UDP]', 'magenta'))
+        self.tx_socket.sendto(data)
+
+    # Called when the subscription to the TX characteristic has changed
+    def on_tx_subscription(self, peer, enabled):
+        print(
+            f'### [GATT TX] subscription from {peer}: '
+            f'{"enabled" if enabled else "disabled"}'
+        )
+        if enabled:
+            self.tx_subscriber = peer
+        else:
+            self.tx_subscriber = None
+
+    # Called when an L2CAP packet is received
+    def on_l2cap_packet(self, packet):
+        print(color(f'<<< [L2CAP PACKET]: {len(packet)} bytes', 'cyan'))
+        print(color('>>> [UDP]', 'magenta'))
+        self.tx_socket.sendto(packet)
+
+    # Called when a new connection is established
+    def on_coc(self, channel):
+        print('*** CoC Connection', channel)
+        self.l2cap_channel = channel
+        channel.sink = self.on_coc_sdu
+
+
+# -----------------------------------------------------------------------------
+async def run(
+    hci_transport,
+    device_address,
+    role_or_peer_address,
+    send_host,
+    send_port,
+    receive_host,
+    receive_port,
+):
     print('<<< connecting to HCI...')
     async with await open_transport_or_link(hci_transport) as (hci_source, hci_sink):
         print('<<< connected')
 
         # Instantiate a bridge object
-        bridge = GattlinkNodeBridge()
+        device = Device.with_hci('Bumble GG', device_address, hci_source, hci_sink)
+
+        # Instantiate a bridge object
+        if role_or_peer_address == 'node':
+            bridge = GattlinkNodeBridge(device)
+        else:
+            bridge = GattlinkHubBridge(device, role_or_peer_address)
 
         # Create a UDP to RX bridge (receive from UDP, send to RX)
         loop = asyncio.get_running_loop()
         await loop.create_datagram_endpoint(
-            lambda: bridge,
-            local_addr=(receive_host, receive_port)
+            lambda: bridge, local_addr=(receive_host, receive_port)
         )
 
         # Create a UDP to TX bridge (receive from TX, send to UDP)
         bridge.tx_socket, _ = await loop.create_datagram_endpoint(
-            lambda: asyncio.DatagramProtocol(),
-            remote_addr=(send_host, send_port)
+            asyncio.DatagramProtocol,
+            remote_addr=(send_host, send_port),
         )
 
-        # Create a device to manage the host, with a custom listener
-        device = Device.with_hci('Bumble', 'F0:F1:F2:F3:F4:F5', hci_source, hci_sink)
-        device.listener = bridge
         await device.power_on()
-
-        # Connect to the peer
-        # print(f'=== Connecting to {device_address}...')
-        # await device.connect(device_address)
-
-        # TODO move to class
-        gattlink_service = Service(
-            GG_GATTLINK_SERVICE_UUID,
-            [
-                Characteristic(
-                    GG_GATTLINK_L2CAP_CHANNEL_PSM_CHARACTERISTIC_UUID,
-                    Characteristic.READ,
-                    Characteristic.READABLE,
-                    bytes([193, 0])
-                )
-            ]
-        )
-        device.add_services([gattlink_service])
-        device.advertising_data = bytes(
-            AdvertisingData([
-                (AdvertisingData.COMPLETE_LOCAL_NAME, bytes('Bumble GG', 'utf-8')),
-                (AdvertisingData.INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS, bytes(reversed(bytes.fromhex('ABBAFF00E56A484CB8328B17CF6CBFE8'))))
-            ])
-        )
-        await device.start_advertising()
+        await bridge.start()
 
         # Wait until the source terminates
         await hci_source.wait_for_termination()
@@ -197,15 +353,44 @@ async def run(hci_transport, device_address, send_host, send_port, receive_host,
 @click.command()
 @click.argument('hci_transport')
 @click.argument('device_address')
-@click.option('-sh', '--send-host', type=str, default='127.0.0.1', help='UDP host to send to')
+@click.argument('role_or_peer_address')
+@click.option(
+    '-sh', '--send-host', type=str, default='127.0.0.1', help='UDP host to send to'
+)
 @click.option('-sp', '--send-port', type=int, default=9001, help='UDP port to send to')
-@click.option('-rh', '--receive-host', type=str, default='127.0.0.1', help='UDP host to receive on')
-@click.option('-rp', '--receive-port', type=int, default=9000, help='UDP port to receive on')
-def main(hci_transport, device_address, send_host, send_port, receive_host, receive_port):
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
-    asyncio.run(run(hci_transport, device_address, send_host, send_port, receive_host, receive_port))
+@click.option(
+    '-rh',
+    '--receive-host',
+    type=str,
+    default='127.0.0.1',
+    help='UDP host to receive on',
+)
+@click.option(
+    '-rp', '--receive-port', type=int, default=9000, help='UDP port to receive on'
+)
+def main(
+    hci_transport,
+    device_address,
+    role_or_peer_address,
+    send_host,
+    send_port,
+    receive_host,
+    receive_port,
+):
+    asyncio.run(
+        run(
+            hci_transport,
+            device_address,
+            role_or_peer_address,
+            send_host,
+            send_port,
+            receive_host,
+            receive_port,
+        )
+    )
 
 
 # -----------------------------------------------------------------------------
+logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
 if __name__ == '__main__':
     main()

apps/hci_bridge.py

@@ -34,16 +34,29 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 async def async_main():
     if len(sys.argv) < 3:
-        print('Usage: hci_bridge.py <host-transport-spec> <controller-transport-spec> [command-short-circuit-list]')
-        print('example: python hci_bridge.py udp:0.0.0.0:9000,127.0.0.1:9001 serial:/dev/tty.usbmodem0006839912171,1000000 0x3f:0x0070,0x3f:0x0074,0x3f:0x0077,0x3f:0x0078')
+        print(
+            'Usage: hci_bridge.py <host-transport-spec> <controller-transport-spec> '
+            '[command-short-circuit-list]'
+        )
+        print(
+            'example: python hci_bridge.py udp:0.0.0.0:9000,127.0.0.1:9001 '
+            'serial:/dev/tty.usbmodem0006839912171,1000000 '
+            '0x3f:0x0070,0x3f:0x0074,0x3f:0x0077,0x3f:0x0078'
+        )
         return
 
     print('>>> connecting to HCI...')
-    async with await transport.open_transport_or_link(sys.argv[1]) as (hci_host_source, hci_host_sink):
+    async with await transport.open_transport_or_link(sys.argv[1]) as (
+        hci_host_source,
+        hci_host_sink,
+    ):
         print('>>> connected')
 
         print('>>> connecting to HCI...')
-        async with await transport.open_transport_or_link(sys.argv[2]) as (hci_controller_source, hci_controller_sink):
+        async with await transport.open_transport_or_link(sys.argv[2]) as (
+            hci_controller_source,
+            hci_controller_sink,
+        ):
             print('>>> connected')
 
             command_short_circuits = []
@@ -51,36 +64,43 @@ async def async_main():
                 for op_code_str in sys.argv[3].split(','):
                     if ':' in op_code_str:
                         ogf, ocf = op_code_str.split(':')
-                        command_short_circuits.append(hci.hci_command_op_code(int(ogf, 16), int(ocf, 16)))
+                        command_short_circuits.append(
+                            hci.hci_command_op_code(int(ogf, 16), int(ocf, 16))
+                        )
                     else:
                         command_short_circuits.append(int(op_code_str, 16))
 
             def host_to_controller_filter(hci_packet):
-                if hci_packet.hci_packet_type == hci.HCI_COMMAND_PACKET and hci_packet.op_code in command_short_circuits:
+                if (
+                    hci_packet.hci_packet_type == hci.HCI_COMMAND_PACKET
+                    and hci_packet.op_code in command_short_circuits
+                ):
                     # Respond with a success response
                     logger.debug('short-circuiting packet')
                     response = hci.HCI_Command_Complete_Event(
-                        num_hci_command_packets = 1,
-                        command_opcode          = hci_packet.op_code,
-                        return_parameters       = bytes([hci.HCI_SUCCESS])
+                        num_hci_command_packets=1,
+                        command_opcode=hci_packet.op_code,
+                        return_parameters=bytes([hci.HCI_SUCCESS]),
                     )
                     # Return a packet with 'respond to sender' set to True
                     return (response.to_bytes(), True)
 
+                return None
+
             _ = HCI_Bridge(
                 hci_host_source,
                 hci_host_sink,
                 hci_controller_source,
                 hci_controller_sink,
                 host_to_controller_filter,
-                None
+                None,
             )
             await asyncio.get_running_loop().create_future()
 
 
 # -----------------------------------------------------------------------------
 def main():
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
     asyncio.run(async_main())
 
 

apps/l2cap_bridge.py

@@ -0,0 +1,350 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import asyncio
+import logging
+import os
+import click
+
+from bumble.colors import color
+from bumble.transport import open_transport_or_link
+from bumble.device import Device
+from bumble.utils import FlowControlAsyncPipe
+from bumble.hci import HCI_Constant
+
+
+# -----------------------------------------------------------------------------
+class ServerBridge:
+    """
+    L2CAP CoC server bridge: waits for a peer to connect an L2CAP CoC channel
+    on a specified PSM. When the connection is made, the bridge connects a TCP
+    socket to a remote host and bridges the data in both directions, with flow
+    control.
+    When the L2CAP CoC channel is closed, the bridge disconnects the TCP socket
+    and waits for a new L2CAP CoC channel to be connected.
+    When the TCP connection is closed by the TCP server, XXXX
+    """
+
+    def __init__(self, psm, max_credits, mtu, mps, tcp_host, tcp_port):
+        self.psm = psm
+        self.max_credits = max_credits
+        self.mtu = mtu
+        self.mps = mps
+        self.tcp_host = tcp_host
+        self.tcp_port = tcp_port
+
+    async def start(self, device):
+        # Listen for incoming L2CAP CoC connections
+        device.register_l2cap_channel_server(
+            psm=self.psm,
+            server=self.on_coc,
+            max_credits=self.max_credits,
+            mtu=self.mtu,
+            mps=self.mps,
+        )
+        print(color(f'### Listening for CoC connection on PSM {self.psm}', 'yellow'))
+
+        def on_ble_connection(connection):
+            def on_ble_disconnection(reason):
+                print(
+                    color('@@@ Bluetooth disconnection:', 'red'),
+                    HCI_Constant.error_name(reason),
+                )
+
+            print(color('@@@ Bluetooth connection:', 'green'), connection)
+            connection.on('disconnection', on_ble_disconnection)
+
+        device.on('connection', on_ble_connection)
+
+        await device.start_advertising(auto_restart=True)
+
+    # Called when a new L2CAP connection is established
+    def on_coc(self, l2cap_channel):
+        print(color('*** L2CAP channel:', 'cyan'), l2cap_channel)
+
+        class Pipe:
+            def __init__(self, bridge, l2cap_channel):
+                self.bridge = bridge
+                self.tcp_transport = None
+                self.l2cap_channel = l2cap_channel
+
+                l2cap_channel.on('close', self.on_l2cap_close)
+                l2cap_channel.sink = self.on_coc_sdu
+
+            async def connect_to_tcp(self):
+                # Connect to the TCP server
+                print(
+                    color(
+                        f'### Connecting to TCP {self.bridge.tcp_host}:'
+                        f'{self.bridge.tcp_port}...',
+                        'yellow',
+                    )
+                )
+
+                class TcpClientProtocol(asyncio.Protocol):
+                    def __init__(self, pipe):
+                        self.pipe = pipe
+
+                    def connection_lost(self, exc):
+                        print(color(f'!!! TCP connection lost: {exc}', 'red'))
+                        if self.pipe.l2cap_channel is not None:
+                            asyncio.create_task(self.pipe.l2cap_channel.disconnect())
+
+                    def data_received(self, data):
+                        print(f'<<< Received on TCP: {len(data)}')
+                        self.pipe.l2cap_channel.write(data)
+
+                try:
+                    (
+                        self.tcp_transport,
+                        _,
+                    ) = await asyncio.get_running_loop().create_connection(
+                        lambda: TcpClientProtocol(self),
+                        host=self.bridge.tcp_host,
+                        port=self.bridge.tcp_port,
+                    )
+                    print(color('### Connected', 'green'))
+                except Exception as error:
+                    print(color(f'!!! Connection failed: {error}', 'red'))
+                    await self.l2cap_channel.disconnect()
+
+            def on_l2cap_close(self):
+                self.l2cap_channel = None
+                if self.tcp_transport is not None:
+                    self.tcp_transport.close()
+
+            def on_coc_sdu(self, sdu):
+                print(color(f'<<< [L2CAP SDU]: {len(sdu)} bytes', 'cyan'))
+                if self.tcp_transport is None:
+                    print(color('!!! TCP socket not open, dropping', 'red'))
+                    return
+                self.tcp_transport.write(sdu)
+
+        pipe = Pipe(self, l2cap_channel)
+
+        asyncio.create_task(pipe.connect_to_tcp())
+
+
+# -----------------------------------------------------------------------------
+class ClientBridge:
+    """
+    L2CAP CoC client bridge: connects to a BLE device, then waits for an inbound
+    TCP connection on a specified port number. When a TCP client connects, an
+    L2CAP CoC channel connection to the BLE device is established, and the data
+    is bridged in both directions, with flow control.
+    When the TCP connection is closed by the client, the L2CAP CoC channel is
+    disconnected, but the connection to the BLE device remains, ready for a new
+    TCP client to connect.
+    When the L2CAP CoC channel is closed, XXXX
+    """
+
+    READ_CHUNK_SIZE = 4096
+
+    def __init__(self, psm, max_credits, mtu, mps, address, tcp_host, tcp_port):
+        self.psm = psm
+        self.max_credits = max_credits
+        self.mtu = mtu
+        self.mps = mps
+        self.address = address
+        self.tcp_host = tcp_host
+        self.tcp_port = tcp_port
+
+    async def start(self, device):
+        print(color(f'### Connecting to {self.address}...', 'yellow'))
+        connection = await device.connect(self.address)
+        print(color('### Connected', 'green'))
+
+        # Called when the BLE connection is disconnected
+        def on_ble_disconnection(reason):
+            print(
+                color('@@@ Bluetooth disconnection:', 'red'),
+                HCI_Constant.error_name(reason),
+            )
+
+        connection.on('disconnection', on_ble_disconnection)
+
+        # Called when a TCP connection is established
+        async def on_tcp_connection(reader, writer):
+            peer_name = writer.get_extra_info('peer_name')
+            print(color(f'<<< TCP connection from {peer_name}', 'magenta'))
+
+            def on_coc_sdu(sdu):
+                print(color(f'<<< [L2CAP SDU]: {len(sdu)} bytes', 'cyan'))
+                l2cap_to_tcp_pipe.write(sdu)
+
+            def on_l2cap_close():
+                print(color('*** L2CAP channel closed', 'red'))
+                l2cap_to_tcp_pipe.stop()
+                writer.close()
+
+            # Connect a new L2CAP channel
+            print(color(f'>>> Opening L2CAP channel on PSM = {self.psm}', 'yellow'))
+            try:
+                l2cap_channel = await connection.open_l2cap_channel(
+                    psm=self.psm,
+                    max_credits=self.max_credits,
+                    mtu=self.mtu,
+                    mps=self.mps,
+                )
+                print(color('*** L2CAP channel:', 'cyan'), l2cap_channel)
+            except Exception as error:
+                print(color(f'!!! Connection failed: {error}', 'red'))
+                writer.close()
+                return
+
+            l2cap_channel.sink = on_coc_sdu
+            l2cap_channel.on('close', on_l2cap_close)
+
+            # Start a flow control pipe from L2CAP to TCP
+            l2cap_to_tcp_pipe = FlowControlAsyncPipe(
+                l2cap_channel.pause_reading,
+                l2cap_channel.resume_reading,
+                writer.write,
+                writer.drain,
+            )
+            l2cap_to_tcp_pipe.start()
+
+            # Pipe data from TCP to L2CAP
+            while True:
+                try:
+                    data = await reader.read(self.READ_CHUNK_SIZE)
+
+                    if len(data) == 0:
+                        print(color('!!! End of stream', 'red'))
+                        await l2cap_channel.disconnect()
+                        return
+
+                    print(color(f'<<< [TCP DATA]: {len(data)} bytes', 'blue'))
+                    l2cap_channel.write(data)
+                    await l2cap_channel.drain()
+                except Exception as error:
+                    print(f'!!! Exception: {error}')
+                    break
+
+            writer.close()
+            print(color('~~~ Bye bye', 'magenta'))
+
+        await asyncio.start_server(
+            on_tcp_connection,
+            host=self.tcp_host if self.tcp_host != '_' else None,
+            port=self.tcp_port,
+        )
+        print(
+            color(
+                f'### Listening for TCP connections on port {self.tcp_port}', 'magenta'
+            )
+        )
+
+
+# -----------------------------------------------------------------------------
+async def run(device_config, hci_transport, bridge):
+    print('<<< connecting to HCI...')
+    async with await open_transport_or_link(hci_transport) as (hci_source, hci_sink):
+        print('<<< connected')
+
+        device = Device.from_config_file_with_hci(device_config, hci_source, hci_sink)
+
+        # Let's go
+        await device.power_on()
+        await bridge.start(device)
+
+        # Wait until the transport terminates
+        await hci_source.wait_for_termination()
+
+
+# -----------------------------------------------------------------------------
+@click.group()
+@click.pass_context
+@click.option('--device-config', help='Device configuration file', required=True)
+@click.option('--hci-transport', help='HCI transport', required=True)
+@click.option('--psm', help='PSM for L2CAP CoC', type=int, default=1234)
+@click.option(
+    '--l2cap-coc-max-credits',
+    help='Maximum L2CAP CoC Credits',
+    type=click.IntRange(1, 65535),
+    default=128,
+)
+@click.option(
+    '--l2cap-coc-mtu',
+    help='L2CAP CoC MTU',
+    type=click.IntRange(23, 65535),
+    default=1022,
+)
+@click.option(
+    '--l2cap-coc-mps',
+    help='L2CAP CoC MPS',
+    type=click.IntRange(23, 65533),
+    default=1024,
+)
+def cli(
+    context,
+    device_config,
+    hci_transport,
+    psm,
+    l2cap_coc_max_credits,
+    l2cap_coc_mtu,
+    l2cap_coc_mps,
+):
+    context.ensure_object(dict)
+    context.obj['device_config'] = device_config
+    context.obj['hci_transport'] = hci_transport
+    context.obj['psm'] = psm
+    context.obj['max_credits'] = l2cap_coc_max_credits
+    context.obj['mtu'] = l2cap_coc_mtu
+    context.obj['mps'] = l2cap_coc_mps
+
+
+# -----------------------------------------------------------------------------
+@cli.command()
+@click.pass_context
+@click.option('--tcp-host', help='TCP host', default='localhost')
+@click.option('--tcp-port', help='TCP port', default=9544)
+def server(context, tcp_host, tcp_port):
+    bridge = ServerBridge(
+        context.obj['psm'],
+        context.obj['max_credits'],
+        context.obj['mtu'],
+        context.obj['mps'],
+        tcp_host,
+        tcp_port,
+    )
+    asyncio.run(run(context.obj['device_config'], context.obj['hci_transport'], bridge))
+
+
+# -----------------------------------------------------------------------------
+@cli.command()
+@click.pass_context
+@click.argument('bluetooth-address')
+@click.option('--tcp-host', help='TCP host', default='_')
+@click.option('--tcp-port', help='TCP port', default=9543)
+def client(context, bluetooth_address, tcp_host, tcp_port):
+    bridge = ClientBridge(
+        context.obj['psm'],
+        context.obj['max_credits'],
+        context.obj['mtu'],
+        context.obj['mps'],
+        bluetooth_address,
+        tcp_host,
+        tcp_port,
+    )
+    asyncio.run(run(context.obj['device_config'], context.obj['hci_transport'], bridge))
+
+
+# -----------------------------------------------------------------------------
+logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
+if __name__ == '__main__':
+    cli(obj={})  # pylint: disable=no-value-for-parameter

apps/link_relay/link_relay.py

@@ -16,7 +16,6 @@
 # Imports
 # ----------------------------------------------------------------------------
 import sys
-import websockets
 import logging
 import json
 import asyncio
@@ -24,7 +23,9 @@ import argparse
 import uuid
 import os
 from urllib.parse import urlparse
-from colors import color
+import websockets
+
+from bumble.colors import color
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -65,9 +66,9 @@ class Connection:
     """
 
     def __init__(self, room, websocket):
-        self.room      = room
+        self.room = room
         self.websocket = websocket
-        self.address   = str(uuid.uuid4())
+        self.address = str(uuid.uuid4())
 
     async def send_message(self, message):
         try:
@@ -98,7 +99,11 @@ class Connection:
         self.address = address
 
     def __str__(self):
-        return f'Connection(address="{self.address}", client={self.websocket.remote_address[0]}:{self.websocket.remote_address[1]})'
+        return (
+            f'Connection(address="{self.address}", '
+            f'client={self.websocket.remote_address[0]}:'
+            f'{self.websocket.remote_address[1]})'
+        )
 
 
 # ----------------------------------------------------------------------------
@@ -110,9 +115,9 @@ class Room:
     """
 
     def __init__(self, relay, name):
-        self.relay       = relay
-        self.name        = name
-        self.observers   = []
+        self.relay = relay
+        self.name = name
+        self.observers = []
         self.connections = []
 
     async def add_connection(self, connection):
@@ -139,13 +144,15 @@ class Room:
 
             # Parse the message to decide how to handle it
             if message.startswith('@'):
-                # This is a targetted message
-                await self.on_targetted_message(connection, message)
+                # This is a targeted message
+                await self.on_targeted_message(connection, message)
             elif message.startswith('/'):
                 # This is an RPC request
                 await self.on_rpc_request(connection, message)
             else:
-                await connection.send_message(f'result:{error_to_json("error: invalid message")}')
+                await connection.send_message(
+                    f'result:{error_to_json("error: invalid message")}'
+                )
 
     async def broadcast_message(self, sender, message):
         '''
@@ -155,7 +162,9 @@ class Room:
 
     async def on_rpc_request(self, connection, message):
         command, *params = message.split(' ', 1)
-        if handler := getattr(self, f'on_{command[1:].lower().replace("-","_")}_command', None):
+        if handler := getattr(
+            self, f'on_{command[1:].lower().replace("-","_")}_command', None
+        ):
             try:
                 result = await handler(connection, params)
             except Exception as error:
@@ -165,7 +174,7 @@ class Room:
 
         await connection.send_message(result or 'result:{}')
 
-    async def on_targetted_message(self, connection, message):
+    async def on_targeted_message(self, connection, message):
         target, *payload = message.split(' ', 1)
         if not payload:
             return error_to_json('missing arguments')
@@ -174,7 +183,8 @@ class Room:
 
         # Determine what targets to send to
         if target == '*':
-            # Send to all connections in the room except the connection from which the message was received
+            # Send to all connections in the room except the connection from which the
+            # message was received
             connections = [c for c in self.connections if c != connection]
         else:
             connections = self.find_connections_by_address(target)
@@ -192,7 +202,9 @@ class Room:
         current_address = connection.address
         new_address = params[0]
         connection.set_address(new_address)
-        await self.broadcast_message(connection, f'address-changed:from={current_address},to={new_address}')
+        await self.broadcast_message(
+            connection, f'address-changed:from={current_address},to={new_address}'
+        )
 
 
 # ----------------------------------------------------------------------------
@@ -210,9 +222,10 @@ class Relay:
     def start(self):
         logger.info(f'Starting Relay on port {self.port}')
 
+        # pylint: disable-next=no-member
         return websockets.serve(self.serve, '0.0.0.0', self.port, ping_interval=None)
 
-    async def serve_as_controller(connection):
+    async def serve_as_controller(self, connection):
         pass
 
     async def serve(self, websocket, path):
@@ -246,24 +259,24 @@ def main():
         print('ERROR: Python 3.6.1 or higher is required')
         sys.exit(1)
 
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
 
     # Parse arguments
     arg_parser = argparse.ArgumentParser(description='Bumble Link Relay')
     arg_parser.add_argument('--log-level', default='INFO', help='logger level')
     arg_parser.add_argument('--log-config', help='logger config file (YAML)')
-    arg_parser.add_argument('--port',
-                            type = int,
-                            default = DEFAULT_RELAY_PORT,
-                            help = 'Port to listen on')
+    arg_parser.add_argument(
+        '--port', type=int, default=DEFAULT_RELAY_PORT, help='Port to listen on'
+    )
     args = arg_parser.parse_args()
 
     # Setup logger
     if args.log_config:
-        from logging import config
+        from logging import config  # pylint: disable=import-outside-toplevel
+
         config.fileConfig(args.log_config)
     else:
-        logging.basicConfig(level = getattr(logging, args.log_level.upper()))
+        logging.basicConfig(level=getattr(logging, args.log_level.upper()))
 
     # Start a relay
     relay = Relay(args.port)

apps/pair.py

@@ -19,9 +19,9 @@ import asyncio
 import os
 import logging
 import click
-import aioconsole
-from colors import color
+from prompt_toolkit.shortcuts import PromptSession
 
+from bumble.colors import color
 from bumble.device import Device, Peer
 from bumble.transport import open_transport_or_link
 from bumble.smp import PairingDelegate, PairingConfig
@@ -33,30 +33,57 @@ from bumble.gatt import (
     GATT_GENERIC_ACCESS_SERVICE,
     Service,
     Characteristic,
-    CharacteristicValue
+    CharacteristicValue,
 )
 from bumble.att import (
     ATT_Error,
     ATT_INSUFFICIENT_AUTHENTICATION_ERROR,
-    ATT_INSUFFICIENT_ENCRYPTION_ERROR
+    ATT_INSUFFICIENT_ENCRYPTION_ERROR,
 )
 
 
 # -----------------------------------------------------------------------------
-class Delegate(PairingDelegate):
-    def __init__(self, mode, connection, capability_string, prompt):
-        super().__init__({
-            'keyboard':         PairingDelegate.KEYBOARD_INPUT_ONLY,
-            'display':          PairingDelegate.DISPLAY_OUTPUT_ONLY,
-            'display+keyboard': PairingDelegate.DISPLAY_OUTPUT_AND_KEYBOARD_INPUT,
-            'display+yes/no':   PairingDelegate.DISPLAY_OUTPUT_AND_YES_NO_INPUT,
-            'none':             PairingDelegate.NO_OUTPUT_NO_INPUT
-        }[capability_string.lower()])
+class Waiter:
+    instance = None
 
-        self.mode      = mode
-        self.peer      = Peer(connection)
+    def __init__(self):
+        self.done = asyncio.get_running_loop().create_future()
+
+    def terminate(self):
+        self.done.set_result(None)
+
+    async def wait_until_terminated(self):
+        return await self.done
+
+
+# -----------------------------------------------------------------------------
+class Delegate(PairingDelegate):
+    def __init__(self, mode, connection, capability_string, do_prompt):
+        super().__init__(
+            {
+                'keyboard': PairingDelegate.KEYBOARD_INPUT_ONLY,
+                'display': PairingDelegate.DISPLAY_OUTPUT_ONLY,
+                'display+keyboard': PairingDelegate.DISPLAY_OUTPUT_AND_KEYBOARD_INPUT,
+                'display+yes/no': PairingDelegate.DISPLAY_OUTPUT_AND_YES_NO_INPUT,
+                'none': PairingDelegate.NO_OUTPUT_NO_INPUT,
+            }[capability_string.lower()]
+        )
+
+        self.mode = mode
+        self.peer = Peer(connection)
         self.peer_name = None
-        self.prompt    = prompt
+        self.do_prompt = do_prompt
+
+    def print(self, message):
+        print(color(message, 'yellow'))
+
+    async def prompt(self, message):
+        # Wait a bit to allow some of the log lines to print before we prompt
+        await asyncio.sleep(1)
+
+        session = PromptSession(message)
+        response = await session.prompt_async()
+        return response.lower().strip()
 
     async def update_peer_name(self):
         if self.peer_name is not None:
@@ -71,87 +98,83 @@ class Delegate(PairingDelegate):
             self.peer_name = '[?]'
 
     async def accept(self):
-        if self.prompt:
+        if self.do_prompt:
             await self.update_peer_name()
 
-            # Wait a bit to allow some of the log lines to print before we prompt
-            await asyncio.sleep(1)
-
             # Prompt for acceptance
-            print(color('###-----------------------------------', 'yellow'))
-            print(color(f'### Pairing request from {self.peer_name}', 'yellow'))
-            print(color('###-----------------------------------', 'yellow'))
+            self.print('###-----------------------------------')
+            self.print(f'### Pairing request from {self.peer_name}')
+            self.print('###-----------------------------------')
             while True:
-                response = await aioconsole.ainput(color('>>> Accept? ', 'yellow'))
-                response = response.lower().strip()
+                response = await self.prompt('>>> Accept? ')
+
                 if response == 'yes':
                     return True
-                elif response == 'no':
+
+                if response == 'no':
                     return False
-        else:
-            # Accept silently
-            return True
+
+        # Accept silently
+        return True
 
     async def compare_numbers(self, number, digits):
         await self.update_peer_name()
 
-        # Wait a bit to allow some of the log lines to print before we prompt
-        await asyncio.sleep(1)
-
         # Prompt for a numeric comparison
-        print(color('###-----------------------------------', 'yellow'))
-        print(color(f'### Pairing with {self.peer_name}', 'yellow'))
-        print(color('###-----------------------------------', 'yellow'))
+        self.print('###-----------------------------------')
+        self.print(f'### Pairing with {self.peer_name}')
+        self.print('###-----------------------------------')
         while True:
-            response = await aioconsole.ainput(color(f'>>> Does the other device display {number:0{digits}}? ', 'yellow'))
-            response = response.lower().strip()
+            response = await self.prompt(
+                f'>>> Does the other device display {number:0{digits}}? '
+            )
+
             if response == 'yes':
                 return True
-            elif response == 'no':
+
+            if response == 'no':
                 return False
 
     async def get_number(self):
         await self.update_peer_name()
 
-        # Wait a bit to allow some of the log lines to print before we prompt
-        await asyncio.sleep(1)
-
         # Prompt for a PIN
         while True:
             try:
-                print(color('###-----------------------------------', 'yellow'))
-                print(color(f'### Pairing with {self.peer_name}', 'yellow'))
-                print(color('###-----------------------------------', 'yellow'))
-                return int(await aioconsole.ainput(color('>>> Enter PIN: ', 'yellow')))
+                self.print('###-----------------------------------')
+                self.print(f'### Pairing with {self.peer_name}')
+                self.print('###-----------------------------------')
+                return int(await self.prompt('>>> Enter PIN: '))
             except ValueError:
                 pass
 
     async def display_number(self, number, digits):
         await self.update_peer_name()
 
-        # Wait a bit to allow some of the log lines to print before we prompt
-        await asyncio.sleep(1)
-
         # Display a PIN code
-        print(color('###-----------------------------------', 'yellow'))
-        print(color(f'### Pairing with {self.peer_name}', 'yellow'))
-        print(color(f'### PIN: {number:0{digits}}', 'yellow'))
-        print(color('###-----------------------------------', 'yellow'))
+        self.print('###-----------------------------------')
+        self.print(f'### Pairing with {self.peer_name}')
+        self.print(f'### PIN: {number:0{digits}}')
+        self.print('###-----------------------------------')
 
 
 # -----------------------------------------------------------------------------
 async def get_peer_name(peer, mode):
     if mode == 'classic':
         return await peer.request_name()
-    else:
-        # Try to get the peer name from GATT
-        services = await peer.discover_service(GATT_GENERIC_ACCESS_SERVICE)
-        if not services:
-            return None
 
-        values = await peer.read_characteristics_by_uuid(GATT_DEVICE_NAME_CHARACTERISTIC, services[0])
-        if values:
-            return values[0].decode('utf-8')
+    # Try to get the peer name from GATT
+    services = await peer.discover_service(GATT_GENERIC_ACCESS_SERVICE)
+    if not services:
+        return None
+
+    values = await peer.read_characteristics_by_uuid(
+        GATT_DEVICE_NAME_CHARACTERISTIC, services[0]
+    )
+    if values:
+        return values[0].decode('utf-8')
+
+    return None
 
 
 # -----------------------------------------------------------------------------
@@ -164,12 +187,12 @@ def read_with_error(connection):
 
     if AUTHENTICATION_ERROR_RETURNED[0]:
         return bytes([1])
-    else:
-        AUTHENTICATION_ERROR_RETURNED[0] = True
-        raise ATT_Error(ATT_INSUFFICIENT_AUTHENTICATION_ERROR)
+
+    AUTHENTICATION_ERROR_RETURNED[0] = True
+    raise ATT_Error(ATT_INSUFFICIENT_AUTHENTICATION_ERROR)
 
 
-def write_with_error(connection, value):
+def write_with_error(connection, _value):
     if not connection.is_encrypted:
         raise ATT_Error(ATT_INSUFFICIENT_ENCRYPTION_ERROR)
 
@@ -183,14 +206,14 @@ def on_connection(connection, request):
     print(color(f'<<< Connection: {connection}', 'green'))
 
     # Listen for pairing events
-    connection.on('pairing_start',   on_pairing_start)
-    connection.on('pairing',         on_pairing)
+    connection.on('pairing_start', on_pairing_start)
+    connection.on('pairing', on_pairing)
     connection.on('pairing_failure', on_pairing_failure)
 
     # Listen for encryption changes
     connection.on(
         'connection_encryption_change',
-        lambda: on_connection_encryption_change(connection)
+        lambda: on_connection_encryption_change(connection),
     )
 
     # Request pairing if needed
@@ -202,7 +225,12 @@ def on_connection(connection, request):
 # -----------------------------------------------------------------------------
 def on_connection_encryption_change(connection):
     print(color('@@@-----------------------------------', 'blue'))
-    print(color(f'@@@ Connection is {"" if connection.is_encrypted else "not"}encrypted', 'blue'))
+    print(
+        color(
+            f'@@@ Connection is {"" if connection.is_encrypted else "not"}encrypted',
+            'blue',
+        )
+    )
     print(color('@@@-----------------------------------', 'blue'))
 
 
@@ -219,6 +247,7 @@ def on_pairing(keys):
     print(color('*** Paired!', 'cyan'))
     keys.print(prefix=color('*** ', 'cyan'))
     print(color('***-----------------------------------', 'cyan'))
+    Waiter.instance.terminate()
 
 
 # -----------------------------------------------------------------------------
@@ -226,6 +255,7 @@ def on_pairing_failure(reason):
     print(color('***-----------------------------------', 'red'))
     print(color(f'*** Pairing failed: {smp_error_name(reason)}', 'red'))
     print(color('***-----------------------------------', 'red'))
+    Waiter.instance.terminate()
 
 
 # -----------------------------------------------------------------------------
@@ -241,8 +271,10 @@ async def pair(
     keystore_file,
     device_config,
     hci_transport,
-    address_or_name
+    address_or_name,
 ):
+    Waiter.instance = Waiter()
+
     print('<<< connecting to HCI...')
     async with await open_transport_or_link(hci_transport) as (hci_source, hci_sink):
         print('<<< connected')
@@ -270,11 +302,14 @@ async def pair(
                     [
                         Characteristic(
                             '552957FB-CF1F-4A31-9535-E78847E1A714',
-                            Characteristic.READ | Characteristic.WRITE,
+                            Characteristic.Properties.READ
+                            | Characteristic.Properties.WRITE,
                             Characteristic.READABLE | Characteristic.WRITEABLE,
-                            CharacteristicValue(read=read_with_error, write=write_with_error)
+                            CharacteristicValue(
+                                read=read_with_error, write=write_with_error
+                            ),
                         )
-                    ]
+                    ],
                 )
             )
 
@@ -288,10 +323,7 @@ async def pair(
 
         # Set up a pairing config factory
         device.pairing_config_factory = lambda connection: PairingConfig(
-            sc,
-            mitm,
-            bond,
-            Delegate(mode, connection, io, prompt)
+            sc, mitm, bond, Delegate(mode, connection, io, prompt)
         )
 
         # Connect to a peer or wait for a connection
@@ -314,26 +346,97 @@ async def pair(
             # Advertise so that peers can find us and connect
             await device.start_advertising(auto_restart=True)
 
-        await hci_source.wait_for_termination()
+        # Run until the user asks to exit
+        await Waiter.instance.wait_until_terminated()
+
+
+# -----------------------------------------------------------------------------
+class LogHandler(logging.Handler):
+    def __init__(self):
+        super().__init__()
+        self.setFormatter(logging.Formatter('%(levelname)s:%(name)s:%(message)s'))
+
+    def emit(self, record):
+        message = self.format(record)
+        print(message)
 
 
 # -----------------------------------------------------------------------------
 @click.command()
-@click.option('--mode', type=click.Choice(['le', 'classic']), default='le', show_default=True)
-@click.option('--sc', type=bool, default=True, help='Use the Secure Connections protocol', show_default=True)
-@click.option('--mitm', type=bool, default=True, help='Request MITM protection', show_default=True)
-@click.option('--bond', type=bool, default=True, help='Enable bonding', show_default=True)
-@click.option('--io', type=click.Choice(['keyboard', 'display', 'display+keyboard', 'display+yes/no', 'none']), default='display+keyboard', show_default=True)
+@click.option(
+    '--mode', type=click.Choice(['le', 'classic']), default='le', show_default=True
+)
+@click.option(
+    '--sc',
+    type=bool,
+    default=True,
+    help='Use the Secure Connections protocol',
+    show_default=True,
+)
+@click.option(
+    '--mitm', type=bool, default=True, help='Request MITM protection', show_default=True
+)
+@click.option(
+    '--bond', type=bool, default=True, help='Enable bonding', show_default=True
+)
+@click.option(
+    '--io',
+    type=click.Choice(
+        ['keyboard', 'display', 'display+keyboard', 'display+yes/no', 'none']
+    ),
+    default='display+keyboard',
+    show_default=True,
+)
 @click.option('--prompt', is_flag=True, help='Prompt to accept/reject pairing request')
-@click.option('--request', is_flag=True, help='Request that the connecting peer initiate pairing')
+@click.option(
+    '--request', is_flag=True, help='Request that the connecting peer initiate pairing'
+)
 @click.option('--print-keys', is_flag=True, help='Print the bond keys before pairing')
-@click.option('--keystore-file', help='File in which to store the pairing keys')
+@click.option(
+    '--keystore-file',
+    metavar='<filename>',
+    help='File in which to store the pairing keys',
+)
 @click.argument('device-config')
 @click.argument('hci_transport')
 @click.argument('address-or-name', required=False)
-def main(mode, sc, mitm, bond, io, prompt, request, print_keys, keystore_file, device_config, hci_transport, address_or_name):
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
-    asyncio.run(pair(mode, sc, mitm, bond, io, prompt, request, print_keys, keystore_file, device_config, hci_transport, address_or_name))
+def main(
+    mode,
+    sc,
+    mitm,
+    bond,
+    io,
+    prompt,
+    request,
+    print_keys,
+    keystore_file,
+    device_config,
+    hci_transport,
+    address_or_name,
+):
+    # Setup logging
+    log_handler = LogHandler()
+    root_logger = logging.getLogger()
+    root_logger.addHandler(log_handler)
+    root_logger.setLevel(os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+
+    # Pair
+    asyncio.run(
+        pair(
+            mode,
+            sc,
+            mitm,
+            bond,
+            io,
+            prompt,
+            request,
+            print_keys,
+            keystore_file,
+            device_config,
+            hci_transport,
+            address_or_name,
+        )
+    )
 
 
 # -----------------------------------------------------------------------------

apps/scan.py

@@ -19,20 +19,20 @@ import asyncio
 import os
 import logging
 import click
-from colors import color
 
+from bumble.colors import color
 from bumble.device import Device
 from bumble.transport import open_transport_or_link
 from bumble.keys import JsonKeyStore
 from bumble.smp import AddressResolver
-from bumble.hci import HCI_LE_Advertising_Report_Event
-from bumble.core import AdvertisingData
+from bumble.device import Advertisement
+from bumble.hci import HCI_Constant, HCI_LE_1M_PHY, HCI_LE_CODED_PHY
 
 
 # -----------------------------------------------------------------------------
 def make_rssi_bar(rssi):
-    DISPLAY_MIN_RSSI       = -105
-    DISPLAY_MAX_RSSI       = -30
+    DISPLAY_MIN_RSSI = -105
+    DISPLAY_MAX_RSSI = -30
     DEFAULT_RSSI_BAR_WIDTH = 30
 
     blocks = ['', '▏', '▎', '▍', '▌', '▋', '▊', '▉']
@@ -48,19 +48,24 @@ class AdvertisementPrinter:
         self.min_rssi = min_rssi
         self.resolver = resolver
 
-    def print_advertisement(self, address, address_color, ad_data, rssi):
-        if self.min_rssi is not None and rssi < self.min_rssi:
+    def print_advertisement(self, advertisement):
+        address = advertisement.address
+        address_color = 'yellow' if advertisement.is_connectable else 'red'
+
+        if self.min_rssi is not None and advertisement.rssi < self.min_rssi:
             return
 
         address_qualifier = ''
         resolution_qualifier = ''
-        if self.resolver and address.is_resolvable:
-            resolved = self.resolver.resolve(address)
+        if self.resolver and advertisement.address.is_resolvable:
+            resolved = self.resolver.resolve(advertisement.address)
             if resolved is not None:
-                resolution_qualifier = f'(resolved from {address})'
+                resolution_qualifier = f'(resolved from {advertisement.address})'
                 address = resolved
 
-        address_type_string = ('PUBLIC', 'RANDOM', 'PUBLIC_ID', 'RANDOM_ID')[address.address_type]
+        address_type_string = ('PUBLIC', 'RANDOM', 'PUBLIC_ID', 'RANDOM_ID')[
+            address.address_type
+        ]
         if address.is_public:
             type_color = 'cyan'
         else:
@@ -74,18 +79,32 @@ class AdvertisementPrinter:
                 type_color = 'blue'
                 address_qualifier = '(non-resolvable)'
 
-        rssi_bar = make_rssi_bar(rssi)
         separator = '\n  '
-        print(f'>>> {color(address, address_color)} [{color(address_type_string, type_color)}]{address_qualifier}{resolution_qualifier}:{separator}RSSI:{rssi:4} {rssi_bar}{separator}{ad_data.to_string(separator)}\n')
+        rssi_bar = make_rssi_bar(advertisement.rssi)
+        if not advertisement.is_legacy:
+            phy_info = (
+                f'PHY: {HCI_Constant.le_phy_name(advertisement.primary_phy)}/'
+                f'{HCI_Constant.le_phy_name(advertisement.secondary_phy)} '
+                f'{separator}'
+            )
+        else:
+            phy_info = ''
 
-    def on_advertisement(self, address, ad_data, rssi, connectable):
-        address_color = 'yellow' if connectable else 'red'
-        self.print_advertisement(address, address_color, ad_data, rssi)
+        print(
+            f'>>> {color(address, address_color)} '
+            f'[{color(address_type_string, type_color)}]{address_qualifier}'
+            f'{resolution_qualifier}:{separator}'
+            f'{phy_info}'
+            f'RSSI:{advertisement.rssi:4} {rssi_bar}{separator}'
+            f'{advertisement.data.to_string(separator)}\n'
+        )
 
-    def on_advertising_report(self, address, ad_data, rssi, event_type):
-        print(f'{color("EVENT", "green")}: {HCI_LE_Advertising_Report_Event.event_type_name(event_type)}')
-        ad_data = AdvertisingData.from_bytes(ad_data)
-        self.print_advertisement(address, 'yellow', ad_data, rssi)
+    def on_advertisement(self, advertisement):
+        self.print_advertisement(advertisement)
+
+    def on_advertising_report(self, report):
+        print(f'{color("EVENT", "green")}: {report.event_type_string()}')
+        self.print_advertisement(Advertisement.from_advertising_report(report))
 
 
 # -----------------------------------------------------------------------------
@@ -94,20 +113,25 @@ async def scan(
     passive,
     scan_interval,
     scan_window,
+    phy,
     filter_duplicates,
     raw,
     keystore_file,
     device_config,
-    transport
+    transport,
 ):
     print('<<< connecting to HCI...')
     async with await open_transport_or_link(transport) as (hci_source, hci_sink):
         print('<<< connected')
 
         if device_config:
-            device = Device.from_config_file_with_hci(device_config, hci_source, hci_sink)
+            device = Device.from_config_file_with_hci(
+                device_config, hci_source, hci_sink
+            )
         else:
-            device = Device.with_hci('Bumble', 'F0:F1:F2:F3:F4:F5', hci_source, hci_sink)
+            device = Device.with_hci(
+                'Bumble', 'F0:F1:F2:F3:F4:F5', hci_source, hci_sink
+            )
 
         if keystore_file:
             keystore = JsonKeyStore(namespace=None, filename=keystore_file)
@@ -126,11 +150,18 @@ async def scan(
             device.on('advertisement', printer.on_advertisement)
 
         await device.power_on()
+
+        if phy is None:
+            scanning_phys = [HCI_LE_1M_PHY, HCI_LE_CODED_PHY]
+        else:
+            scanning_phys = [{'1m': HCI_LE_1M_PHY, 'coded': HCI_LE_CODED_PHY}[phy]]
+
         await device.start_scanning(
             active=(not passive),
             scan_interval=scan_interval,
             scan_window=scan_window,
-            filter_duplicates=filter_duplicates
+            filter_duplicates=filter_duplicates,
+            scanning_phys=scanning_phys,
         )
 
         await hci_source.wait_for_termination()
@@ -142,14 +173,51 @@ async def scan(
 @click.option('--passive', is_flag=True, default=False, help='Perform passive scanning')
 @click.option('--scan-interval', type=int, default=60, help='Scan interval')
 @click.option('--scan-window', type=int, default=60, help='Scan window')
-@click.option('--filter-duplicates', type=bool, default=True, help='Filter duplicates at the controller level')
-@click.option('--raw', is_flag=True, default=False, help='Listen for raw advertising reports instead of processed ones')
+@click.option(
+    '--phy', type=click.Choice(['1m', 'coded']), help='Only scan on the specified PHY'
+)
+@click.option(
+    '--filter-duplicates',
+    type=bool,
+    default=True,
+    help='Filter duplicates at the controller level',
+)
+@click.option(
+    '--raw',
+    is_flag=True,
+    default=False,
+    help='Listen for raw advertising reports instead of processed ones',
+)
 @click.option('--keystore-file', help='Keystore file to use when resolving addresses')
 @click.option('--device-config', help='Device config file for the scanning device')
 @click.argument('transport')
-def main(min_rssi, passive, scan_interval, scan_window, filter_duplicates, raw, keystore_file, device_config, transport):
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
-    asyncio.run(scan(min_rssi, passive, scan_interval, scan_window, filter_duplicates, raw, keystore_file, device_config, transport))
+def main(
+    min_rssi,
+    passive,
+    scan_interval,
+    scan_window,
+    phy,
+    filter_duplicates,
+    raw,
+    keystore_file,
+    device_config,
+    transport,
+):
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
+    asyncio.run(
+        scan(
+            min_rssi,
+            passive,
+            scan_interval,
+            scan_window,
+            phy,
+            filter_duplicates,
+            raw,
+            keystore_file,
+            device_config,
+            transport,
+        )
+    )
 
 
 # -----------------------------------------------------------------------------

apps/show.py

@@ -17,8 +17,8 @@
 # -----------------------------------------------------------------------------
 import struct
 import click
-from colors import color
 
+from bumble.colors import color
 from bumble import hci
 from bumble.transport.common import PacketReader
 from bumble.helpers import PacketTracer
@@ -27,13 +27,14 @@ from bumble.helpers import PacketTracer
 # -----------------------------------------------------------------------------
 class SnoopPacketReader:
     '''
-    Reader that reads HCI packets from a "snoop" file (based on RFC 1761, but not exactly the same...)
+    Reader that reads HCI packets from a "snoop" file (based on RFC 1761, but not
+    exactly the same...)
     '''
 
-    DATALINK_H1   = 1001
-    DATALINK_H4   = 1002
+    DATALINK_H1 = 1001
+    DATALINK_H4 = 1002
     DATALINK_BSCP = 1003
-    DATALINK_H5   = 1004
+    DATALINK_H5 = 1004
 
     def __init__(self, source):
         self.source = source
@@ -41,9 +42,13 @@ class SnoopPacketReader:
         # Read the header
         identification_pattern = source.read(8)
         if identification_pattern.hex().lower() != '6274736e6f6f7000':
-            raise ValueError('not a valid snoop file, unexpected identification pattern')
-        (self.version_number, self.data_link_type) = struct.unpack('>II', source.read(8))
-        if self.data_link_type != self.DATALINK_H4 and self.data_link_type != self.DATALINK_H1:
+            raise ValueError(
+                'not a valid snoop file, unexpected identification pattern'
+            )
+        (self.version_number, self.data_link_type) = struct.unpack(
+            '>II', source.read(8)
+        )
+        if self.data_link_type not in (self.DATALINK_H4, self.DATALINK_H1):
             raise ValueError(f'datalink type {self.data_link_type} not supported')
 
     def next_packet(self):
@@ -55,9 +60,9 @@ class SnoopPacketReader:
             original_length,
             included_length,
             packet_flags,
-            cumulative_drops,
-            timestamp_seconds,
-            timestamp_microsecond
+            _cumulative_drops,
+            _timestamp_seconds,
+            _timestamp_microsecond,
         ) = struct.unpack('>IIIIII', header)
 
         # Abort on truncated packets
@@ -79,24 +84,34 @@ class SnoopPacketReader:
                 else:
                     packet_type = hci.HCI_ACL_DATA_PACKET
 
-            return (packet_flags & 1, bytes([packet_type]) + self.source.read(included_length))
-        else:
-            return (packet_flags & 1, self.source.read(included_length))
+            return (
+                packet_flags & 1,
+                bytes([packet_type]) + self.source.read(included_length),
+            )
+
+        return (packet_flags & 1, self.source.read(included_length))
 
 
 # -----------------------------------------------------------------------------
 # Main
 # -----------------------------------------------------------------------------
 @click.command()
-@click.option('--format', type=click.Choice(['h4', 'snoop']), default='h4', help='Format of the input file')
+@click.option(
+    '--format',
+    type=click.Choice(['h4', 'snoop']),
+    default='h4',
+    help='Format of the input file',
+)
 @click.argument('filename')
-def show(format, filename):
+# pylint: disable=redefined-builtin
+def main(format, filename):
     input = open(filename, 'rb')
     if format == 'h4':
         packet_reader = PacketReader(input)
 
         def read_next_packet():
-            (0, packet_reader.next_packet())
+            return (0, packet_reader.next_packet())
+
     else:
         packet_reader = SnoopPacketReader(input)
         read_next_packet = packet_reader.next_packet
@@ -112,9 +127,8 @@ def show(format, filename):
 
         except Exception as error:
             print(color(f'!!! {error}', 'red'))
-            pass
 
 
 # -----------------------------------------------------------------------------
 if __name__ == '__main__':
-    show()
+    main()  # pylint: disable=no-value-for-parameter

apps/unbond.py

@@ -54,7 +54,7 @@ async def unbond(keystore_file, device_config, address):
 @click.argument('device-config')
 @click.argument('address', required=False)
 def main(keystore_file, device_config, address):
-    logging.basicConfig(level = os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
     asyncio.run(unbond(keystore_file, device_config, address))
 
 

apps/usb_probe.py

@@ -0,0 +1,278 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# This tool lists all the USB devices, with details about each device.
+# For each device, the different possible Bumble transport strings that can
+# refer to it are listed. If the device is known to be a Bluetooth HCI device,
+# its identifier is printed in reverse colors, and the transport names in cyan color.
+# For other devices, regardless of their type, the transport names are printed
+# in red. Whether that device is actually a Bluetooth device or not depends on
+# whether it is a Bluetooth device that uses a non-standard Class, or some other
+# type of device (there's no way to tell).
+# -----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import os
+import logging
+import click
+import usb1
+
+from bumble.colors import color
+from bumble.transport.usb import load_libusb
+
+
+# -----------------------------------------------------------------------------
+# Constants
+# -----------------------------------------------------------------------------
+USB_DEVICE_CLASS_DEVICE = 0x00
+USB_DEVICE_CLASS_WIRELESS_CONTROLLER = 0xE0
+USB_DEVICE_SUBCLASS_RF_CONTROLLER = 0x01
+USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER = 0x01
+
+USB_DEVICE_CLASSES = {
+    0x00: 'Device',
+    0x01: 'Audio',
+    0x02: 'Communications and CDC Control',
+    0x03: 'Human Interface Device',
+    0x05: 'Physical',
+    0x06: 'Still Imaging',
+    0x07: 'Printer',
+    0x08: 'Mass Storage',
+    0x09: 'Hub',
+    0x0A: 'CDC Data',
+    0x0B: 'Smart Card',
+    0x0D: 'Content Security',
+    0x0E: 'Video',
+    0x0F: 'Personal Healthcare',
+    0x10: 'Audio/Video',
+    0x11: 'Billboard',
+    0x12: 'USB Type-C Bridge',
+    0x3C: 'I3C',
+    0xDC: 'Diagnostic',
+    USB_DEVICE_CLASS_WIRELESS_CONTROLLER: (
+        'Wireless Controller',
+        {
+            0x01: {
+                0x01: 'Bluetooth',
+                0x02: 'UWB',
+                0x03: 'Remote NDIS',
+                0x04: 'Bluetooth AMP',
+            }
+        },
+    ),
+    0xEF: 'Miscellaneous',
+    0xFE: 'Application Specific',
+    0xFF: 'Vendor Specific',
+}
+
+USB_ENDPOINT_IN = 0x80
+USB_ENDPOINT_TYPES = ['CONTROL', 'ISOCHRONOUS', 'BULK', 'INTERRUPT']
+
+USB_BT_HCI_CLASS_TUPLE = (
+    USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
+    USB_DEVICE_SUBCLASS_RF_CONTROLLER,
+    USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER,
+)
+
+
+# -----------------------------------------------------------------------------
+def show_device_details(device):
+    for configuration in device:
+        print(f'  Configuration {configuration.getConfigurationValue()}')
+        for interface in configuration:
+            for setting in interface:
+                alternate_setting = setting.getAlternateSetting()
+                suffix = (
+                    f'/{alternate_setting}' if interface.getNumSettings() > 1 else ''
+                )
+                (class_string, subclass_string) = get_class_info(
+                    setting.getClass(), setting.getSubClass(), setting.getProtocol()
+                )
+                details = f'({class_string}, {subclass_string})'
+                print(f'      Interface: {setting.getNumber()}{suffix} {details}')
+                for endpoint in setting:
+                    endpoint_type = USB_ENDPOINT_TYPES[endpoint.getAttributes() & 3]
+                    endpoint_direction = (
+                        'OUT'
+                        if (endpoint.getAddress() & USB_ENDPOINT_IN == 0)
+                        else 'IN'
+                    )
+                    print(
+                        f'        Endpoint 0x{endpoint.getAddress():02X}: '
+                        f'{endpoint_type} {endpoint_direction}'
+                    )
+
+
+# -----------------------------------------------------------------------------
+def get_class_info(cls, subclass, protocol):
+    class_info = USB_DEVICE_CLASSES.get(cls)
+    protocol_string = ''
+    if class_info is None:
+        class_string = f'0x{cls:02X}'
+    else:
+        if isinstance(class_info, tuple):
+            class_string = class_info[0]
+            subclass_info = class_info[1].get(subclass)
+            if subclass_info:
+                protocol_string = subclass_info.get(protocol)
+                if protocol_string is not None:
+                    protocol_string = f' [{protocol_string}]'
+
+        else:
+            class_string = class_info
+
+    subclass_string = f'{subclass}/{protocol}{protocol_string}'
+
+    return (class_string, subclass_string)
+
+
+# -----------------------------------------------------------------------------
+def is_bluetooth_hci(device):
+    # Check if the device class indicates a match
+    if (
+        device.getDeviceClass(),
+        device.getDeviceSubClass(),
+        device.getDeviceProtocol(),
+    ) == USB_BT_HCI_CLASS_TUPLE:
+        return True
+
+    # If the device class is 'Device', look for a matching interface
+    if device.getDeviceClass() == USB_DEVICE_CLASS_DEVICE:
+        for configuration in device:
+            for interface in configuration:
+                for setting in interface:
+                    if (
+                        setting.getClass(),
+                        setting.getSubClass(),
+                        setting.getProtocol(),
+                    ) == USB_BT_HCI_CLASS_TUPLE:
+                        return True
+
+    return False
+
+
+# -----------------------------------------------------------------------------
+@click.command()
+@click.option('--verbose', is_flag=True, default=False, help='Print more details')
+def main(verbose):
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
+
+    load_libusb()
+    with usb1.USBContext() as context:
+        bluetooth_device_count = 0
+        devices = {}
+
+        for device in context.getDeviceIterator(skip_on_error=True):
+            device_class = device.getDeviceClass()
+            device_subclass = device.getDeviceSubClass()
+            device_protocol = device.getDeviceProtocol()
+
+            device_id = (device.getVendorID(), device.getProductID())
+
+            (device_class_string, device_subclass_string) = get_class_info(
+                device_class, device_subclass, device_protocol
+            )
+
+            try:
+                device_serial_number = device.getSerialNumber()
+            except usb1.USBError:
+                device_serial_number = None
+
+            try:
+                device_manufacturer = device.getManufacturer()
+            except usb1.USBError:
+                device_manufacturer = None
+
+            try:
+                device_product = device.getProduct()
+            except usb1.USBError:
+                device_product = None
+
+            device_is_bluetooth_hci = is_bluetooth_hci(device)
+            if device_is_bluetooth_hci:
+                bluetooth_device_count += 1
+                fg_color = 'black'
+                bg_color = 'yellow'
+            else:
+                fg_color = 'yellow'
+                bg_color = 'black'
+
+            # Compute the different ways this can be referenced as a Bumble transport
+            bumble_transport_names = []
+            basic_transport_name = (
+                f'usb:{device.getVendorID():04X}:{device.getProductID():04X}'
+            )
+
+            if device_is_bluetooth_hci:
+                bumble_transport_names.append(f'usb:{bluetooth_device_count - 1}')
+
+            if device_id not in devices:
+                bumble_transport_names.append(basic_transport_name)
+            else:
+                bumble_transport_names.append(
+                    f'{basic_transport_name}#{len(devices[device_id])}'
+                )
+
+            if device_serial_number is not None:
+                if (
+                    device_id not in devices
+                    or device_serial_number not in devices[device_id]
+                ):
+                    bumble_transport_names.append(
+                        f'{basic_transport_name}/{device_serial_number}'
+                    )
+
+            # Print the results
+            print(
+                color(
+                    f'ID {device.getVendorID():04X}:{device.getProductID():04X}',
+                    fg=fg_color,
+                    bg=bg_color,
+                )
+            )
+            if bumble_transport_names:
+                print(
+                    color('  Bumble Transport Names:', 'blue'),
+                    ' or '.join(
+                        color(x, 'cyan' if device_is_bluetooth_hci else 'red')
+                        for x in bumble_transport_names
+                    ),
+                )
+            print(
+                color('  Bus/Device:            ', 'green'),
+                f'{device.getBusNumber():03}/{device.getDeviceAddress():03}',
+            )
+            print(color('  Class:                 ', 'green'), device_class_string)
+            print(color('  Subclass/Protocol:     ', 'green'), device_subclass_string)
+            if device_serial_number is not None:
+                print(color('  Serial:                ', 'green'), device_serial_number)
+            if device_manufacturer is not None:
+                print(color('  Manufacturer:          ', 'green'), device_manufacturer)
+            if device_product is not None:
+                print(color('  Product:               ', 'green'), device_product)
+
+            if verbose:
+                show_device_details(device)
+
+            print()
+
+            devices.setdefault(device_id, []).append(device_serial_number)
+
+
+# -----------------------------------------------------------------------------
+if __name__ == '__main__':
+    main()  # pylint: disable=no-value-for-parameter

bumble/__init__.py

@@ -0,0 +1,4 @@
+try:
+    from ._version import version as __version__
+except ImportError:
+    __version__ = "unknown version"

bumble/a2dp.py

@@ -16,10 +16,8 @@
 # Imports
 # -----------------------------------------------------------------------------
 import struct
-import bitstruct
 import logging
 from collections import namedtuple
-from colors import color
 
 from .company_ids import COMPANY_IDENTIFIERS
 from .sdp import (
@@ -30,7 +28,7 @@ from .sdp import (
     SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID,
     SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID,
     SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID,
-    SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID
+    SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID,
 )
 from .core import (
     BT_L2CAP_PROTOCOL_ID,
@@ -38,7 +36,7 @@ from .core import (
     BT_AUDIO_SINK_SERVICE,
     BT_AVDTP_PROTOCOL_ID,
     BT_ADVANCED_AUDIO_DISTRIBUTION_SERVICE,
-    name_or_number
+    name_or_number,
 )
 
 
@@ -51,6 +49,7 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
 
 A2DP_SBC_CODEC_TYPE            = 0x00
 A2DP_MPEG_1_2_AUDIO_CODEC_TYPE = 0x01
@@ -127,71 +126,115 @@ MPEG_2_4_OBJECT_TYPE_NAMES = {
     MPEG_4_AAC_SCALABLE_OBJECT_TYPE: 'MPEG_4_AAC_SCALABLE_OBJECT_TYPE'
 }
 
+# fmt: on
+
 
 # -----------------------------------------------------------------------------
 def flags_to_list(flags, values):
     result = []
-    for i in range(len(values)):
+    for i, value in enumerate(values):
         if flags & (1 << (len(values) - i - 1)):
-            result.append(values[i])
+            result.append(value)
     return result
 
 
 # -----------------------------------------------------------------------------
 def make_audio_source_service_sdp_records(service_record_handle, version=(1, 3)):
+    # pylint: disable=import-outside-toplevel
     from .avdtp import AVDTP_PSM
+
     version_int = version[0] << 8 | version[1]
     return [
-        ServiceAttribute(SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID, DataElement.unsigned_integer_32(service_record_handle)),
-        ServiceAttribute(SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(SDP_PUBLIC_BROWSE_ROOT)
-        ])),
-        ServiceAttribute(SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(BT_AUDIO_SOURCE_SERVICE)
-        ])),
-        ServiceAttribute(SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.sequence([
-                DataElement.uuid(BT_L2CAP_PROTOCOL_ID),
-                DataElement.unsigned_integer_16(AVDTP_PSM)
-            ]),
-            DataElement.sequence([
-                DataElement.uuid(BT_AVDTP_PROTOCOL_ID),
-                DataElement.unsigned_integer_16(version_int)
-            ])
-        ])),
-        ServiceAttribute(SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(BT_ADVANCED_AUDIO_DISTRIBUTION_SERVICE),
-            DataElement.unsigned_integer_16(version_int)
-        ])),
+        ServiceAttribute(
+            SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID,
+            DataElement.unsigned_integer_32(service_record_handle),
+        ),
+        ServiceAttribute(
+            SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID,
+            DataElement.sequence([DataElement.uuid(SDP_PUBLIC_BROWSE_ROOT)]),
+        ),
+        ServiceAttribute(
+            SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID,
+            DataElement.sequence([DataElement.uuid(BT_AUDIO_SOURCE_SERVICE)]),
+        ),
+        ServiceAttribute(
+            SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID,
+            DataElement.sequence(
+                [
+                    DataElement.sequence(
+                        [
+                            DataElement.uuid(BT_L2CAP_PROTOCOL_ID),
+                            DataElement.unsigned_integer_16(AVDTP_PSM),
+                        ]
+                    ),
+                    DataElement.sequence(
+                        [
+                            DataElement.uuid(BT_AVDTP_PROTOCOL_ID),
+                            DataElement.unsigned_integer_16(version_int),
+                        ]
+                    ),
+                ]
+            ),
+        ),
+        ServiceAttribute(
+            SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID,
+            DataElement.sequence(
+                [
+                    DataElement.uuid(BT_ADVANCED_AUDIO_DISTRIBUTION_SERVICE),
+                    DataElement.unsigned_integer_16(version_int),
+                ]
+            ),
+        ),
     ]
 
 
 # -----------------------------------------------------------------------------
 def make_audio_sink_service_sdp_records(service_record_handle, version=(1, 3)):
+    # pylint: disable=import-outside-toplevel
     from .avdtp import AVDTP_PSM
+
     version_int = version[0] << 8 | version[1]
     return [
-        ServiceAttribute(SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID, DataElement.unsigned_integer_32(service_record_handle)),
-        ServiceAttribute(SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(SDP_PUBLIC_BROWSE_ROOT)
-        ])),
-        ServiceAttribute(SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(BT_AUDIO_SINK_SERVICE)
-        ])),
-        ServiceAttribute(SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.sequence([
-                DataElement.uuid(BT_L2CAP_PROTOCOL_ID),
-                DataElement.unsigned_integer_16(AVDTP_PSM)
-            ]),
-            DataElement.sequence([
-                DataElement.uuid(BT_AVDTP_PROTOCOL_ID),
-                DataElement.unsigned_integer_16(version_int)
-            ])
-        ])),
-        ServiceAttribute(SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID, DataElement.sequence([
-            DataElement.uuid(BT_ADVANCED_AUDIO_DISTRIBUTION_SERVICE),
-            DataElement.unsigned_integer_16(version_int)
-        ])),
+        ServiceAttribute(
+            SDP_SERVICE_RECORD_HANDLE_ATTRIBUTE_ID,
+            DataElement.unsigned_integer_32(service_record_handle),
+        ),
+        ServiceAttribute(
+            SDP_BROWSE_GROUP_LIST_ATTRIBUTE_ID,
+            DataElement.sequence([DataElement.uuid(SDP_PUBLIC_BROWSE_ROOT)]),
+        ),
+        ServiceAttribute(
+            SDP_SERVICE_CLASS_ID_LIST_ATTRIBUTE_ID,
+            DataElement.sequence([DataElement.uuid(BT_AUDIO_SINK_SERVICE)]),
+        ),
+        ServiceAttribute(
+            SDP_PROTOCOL_DESCRIPTOR_LIST_ATTRIBUTE_ID,
+            DataElement.sequence(
+                [
+                    DataElement.sequence(
+                        [
+                            DataElement.uuid(BT_L2CAP_PROTOCOL_ID),
+                            DataElement.unsigned_integer_16(AVDTP_PSM),
+                        ]
+                    ),
+                    DataElement.sequence(
+                        [
+                            DataElement.uuid(BT_AVDTP_PROTOCOL_ID),
+                            DataElement.unsigned_integer_16(version_int),
+                        ]
+                    ),
+                ]
+            ),
+        ),
+        ServiceAttribute(
+            SDP_BLUETOOTH_PROFILE_DESCRIPTOR_LIST_ATTRIBUTE_ID,
+            DataElement.sequence(
+                [
+                    DataElement.uuid(BT_ADVANCED_AUDIO_DISTRIBUTION_SERVICE),
+                    DataElement.unsigned_integer_16(version_int),
+                ]
+            ),
+        ),
     ]
 
 
@@ -206,45 +249,46 @@ class SbcMediaCodecInformation(
             'subbands',
             'allocation_method',
             'minimum_bitpool_value',
-            'maximum_bitpool_value'
-        ]
+            'maximum_bitpool_value',
+        ],
     )
 ):
     '''
     A2DP spec - 4.3.2 Codec Specific Information Elements
     '''
 
-    BIT_FIELDS = 'u4u4u4u2u2u8u8'
-    SAMPLING_FREQUENCY_BITS = {
-        16000: 1 << 3,
-        32000: 1 << 2,
-        44100: 1 << 1,
-        48000: 1
-    }
+    SAMPLING_FREQUENCY_BITS = {16000: 1 << 3, 32000: 1 << 2, 44100: 1 << 1, 48000: 1}
     CHANNEL_MODE_BITS = {
-        SBC_MONO_CHANNEL_MODE:         1 << 3,
-        SBC_DUAL_CHANNEL_MODE:         1 << 2,
-        SBC_STEREO_CHANNEL_MODE:       1 << 1,
-        SBC_JOINT_STEREO_CHANNEL_MODE: 1
-    }
-    BLOCK_LENGTH_BITS = {
-        4:  1 << 3,
-        8:  1 << 2,
-        12: 1 << 1,
-        16: 1
-    }
-    SUBBANDS_BITS = {
-        4: 1 << 1,
-        8: 1
+        SBC_MONO_CHANNEL_MODE: 1 << 3,
+        SBC_DUAL_CHANNEL_MODE: 1 << 2,
+        SBC_STEREO_CHANNEL_MODE: 1 << 1,
+        SBC_JOINT_STEREO_CHANNEL_MODE: 1,
     }
+    BLOCK_LENGTH_BITS = {4: 1 << 3, 8: 1 << 2, 12: 1 << 1, 16: 1}
+    SUBBANDS_BITS = {4: 1 << 1, 8: 1}
     ALLOCATION_METHOD_BITS = {
-        SBC_SNR_ALLOCATION_METHOD:      1 << 1,
-        SBC_LOUDNESS_ALLOCATION_METHOD: 1
+        SBC_SNR_ALLOCATION_METHOD: 1 << 1,
+        SBC_LOUDNESS_ALLOCATION_METHOD: 1,
     }
 
     @staticmethod
-    def from_bytes(data):
-        return SbcMediaCodecInformation(*bitstruct.unpack(SbcMediaCodecInformation.BIT_FIELDS, data))
+    def from_bytes(data: bytes) -> 'SbcMediaCodecInformation':
+        sampling_frequency = (data[0] >> 4) & 0x0F
+        channel_mode = (data[0] >> 0) & 0x0F
+        block_length = (data[1] >> 4) & 0x0F
+        subbands = (data[1] >> 2) & 0x03
+        allocation_method = (data[1] >> 0) & 0x03
+        minimum_bitpool_value = (data[2] >> 0) & 0xFF
+        maximum_bitpool_value = (data[3] >> 0) & 0xFF
+        return SbcMediaCodecInformation(
+            sampling_frequency,
+            channel_mode,
+            block_length,
+            subbands,
+            allocation_method,
+            minimum_bitpool_value,
+            maximum_bitpool_value,
+        )
 
     @classmethod
     def from_discrete_values(
@@ -255,16 +299,16 @@ class SbcMediaCodecInformation(
         subbands,
         allocation_method,
         minimum_bitpool_value,
-        maximum_bitpool_value
+        maximum_bitpool_value,
     ):
         return SbcMediaCodecInformation(
-            sampling_frequency    = cls.SAMPLING_FREQUENCY_BITS[sampling_frequency],
-            channel_mode          = cls.CHANNEL_MODE_BITS[channel_mode],
-            block_length          = cls.BLOCK_LENGTH_BITS[block_length],
-            subbands              = cls.SUBBANDS_BITS[subbands],
-            allocation_method     = cls.ALLOCATION_METHOD_BITS[allocation_method],
-            minimum_bitpool_value = minimum_bitpool_value,
-            maximum_bitpool_value = maximum_bitpool_value
+            sampling_frequency=cls.SAMPLING_FREQUENCY_BITS[sampling_frequency],
+            channel_mode=cls.CHANNEL_MODE_BITS[channel_mode],
+            block_length=cls.BLOCK_LENGTH_BITS[block_length],
+            subbands=cls.SUBBANDS_BITS[subbands],
+            allocation_method=cls.ALLOCATION_METHOD_BITS[allocation_method],
+            minimum_bitpool_value=minimum_bitpool_value,
+            maximum_bitpool_value=maximum_bitpool_value,
         )
 
     @classmethod
@@ -276,63 +320,71 @@ class SbcMediaCodecInformation(
         subbands,
         allocation_methods,
         minimum_bitpool_value,
-        maximum_bitpool_value
+        maximum_bitpool_value,
     ):
         return SbcMediaCodecInformation(
-            sampling_frequency    = sum(cls.SAMPLING_FREQUENCY_BITS[x] for x in sampling_frequencies),
-            channel_mode          = sum(cls.CHANNEL_MODE_BITS[x] for x in channel_modes),
-            block_length          = sum(cls.BLOCK_LENGTH_BITS[x] for x in block_lengths),
-            subbands              = sum(cls.SUBBANDS_BITS[x] for x in subbands),
-            allocation_method     = sum(cls.ALLOCATION_METHOD_BITS[x] for x in allocation_methods),
-            minimum_bitpool_value = minimum_bitpool_value,
-            maximum_bitpool_value = maximum_bitpool_value
+            sampling_frequency=sum(
+                cls.SAMPLING_FREQUENCY_BITS[x] for x in sampling_frequencies
+            ),
+            channel_mode=sum(cls.CHANNEL_MODE_BITS[x] for x in channel_modes),
+            block_length=sum(cls.BLOCK_LENGTH_BITS[x] for x in block_lengths),
+            subbands=sum(cls.SUBBANDS_BITS[x] for x in subbands),
+            allocation_method=sum(
+                cls.ALLOCATION_METHOD_BITS[x] for x in allocation_methods
+            ),
+            minimum_bitpool_value=minimum_bitpool_value,
+            maximum_bitpool_value=maximum_bitpool_value,
         )
 
-    def __bytes__(self):
-        return bitstruct.pack(self.BIT_FIELDS, *self)
+    def __bytes__(self) -> bytes:
+        return bytes(
+            [
+                (self.sampling_frequency << 4) | self.channel_mode,
+                (self.block_length << 4)
+                | (self.subbands << 2)
+                | self.allocation_method,
+                self.minimum_bitpool_value,
+                self.maximum_bitpool_value,
+            ]
+        )
 
     def __str__(self):
         channel_modes = ['MONO', 'DUAL_CHANNEL', 'STEREO', 'JOINT_STEREO']
         allocation_methods = ['SNR', 'Loudness']
-        return '\n'.join([
-            'SbcMediaCodecInformation(',
-            f'  sampling_frequency:    {",".join([str(x) for x in flags_to_list(self.sampling_frequency, SBC_SAMPLING_FREQUENCIES)])}',
-            f'  channel_mode:          {",".join([str(x) for x in flags_to_list(self.channel_mode, channel_modes)])}',
-            f'  block_length:          {",".join([str(x) for x in flags_to_list(self.block_length, SBC_BLOCK_LENGTHS)])}',
-            f'  subbands:              {",".join([str(x) for x in flags_to_list(self.subbands, SBC_SUBBANDS)])}',
-            f'  allocation_method:     {",".join([str(x) for x in flags_to_list(self.allocation_method, allocation_methods)])}',
-            f'  minimum_bitpool_value: {self.minimum_bitpool_value}',
-            f'  maximum_bitpool_value: {self.maximum_bitpool_value}'
-            ')'
-        ])
+        return '\n'.join(
+            # pylint: disable=line-too-long
+            [
+                'SbcMediaCodecInformation(',
+                f'  sampling_frequency:    {",".join([str(x) for x in flags_to_list(self.sampling_frequency, SBC_SAMPLING_FREQUENCIES)])}',
+                f'  channel_mode:          {",".join([str(x) for x in flags_to_list(self.channel_mode, channel_modes)])}',
+                f'  block_length:          {",".join([str(x) for x in flags_to_list(self.block_length, SBC_BLOCK_LENGTHS)])}',
+                f'  subbands:              {",".join([str(x) for x in flags_to_list(self.subbands, SBC_SUBBANDS)])}',
+                f'  allocation_method:     {",".join([str(x) for x in flags_to_list(self.allocation_method, allocation_methods)])}',
+                f'  minimum_bitpool_value: {self.minimum_bitpool_value}',
+                f'  maximum_bitpool_value: {self.maximum_bitpool_value}' ')',
+            ]
+        )
 
 
 # -----------------------------------------------------------------------------
 class AacMediaCodecInformation(
     namedtuple(
         'AacMediaCodecInformation',
-        [
-            'object_type',
-            'sampling_frequency',
-            'channels',
-            'vbr',
-            'bitrate'
-        ]
+        ['object_type', 'sampling_frequency', 'channels', 'rfa', 'vbr', 'bitrate'],
     )
 ):
     '''
     A2DP spec - 4.5.2 Codec Specific Information Elements
     '''
 
-    BIT_FIELDS = 'u8u12u2p2u1u23'
     OBJECT_TYPE_BITS = {
-        MPEG_2_AAC_LC_OBJECT_TYPE:       1 << 7,
-        MPEG_4_AAC_LC_OBJECT_TYPE:       1 << 6,
-        MPEG_4_AAC_LTP_OBJECT_TYPE:      1 << 5,
-        MPEG_4_AAC_SCALABLE_OBJECT_TYPE: 1 << 4
+        MPEG_2_AAC_LC_OBJECT_TYPE: 1 << 7,
+        MPEG_4_AAC_LC_OBJECT_TYPE: 1 << 6,
+        MPEG_4_AAC_LTP_OBJECT_TYPE: 1 << 5,
+        MPEG_4_AAC_SCALABLE_OBJECT_TYPE: 1 << 4,
     }
     SAMPLING_FREQUENCY_BITS = {
-        8000:  1 << 11,
+        8000: 1 << 11,
         11025: 1 << 10,
         12000: 1 << 9,
         16000: 1 << 8,
@@ -343,66 +395,82 @@ class AacMediaCodecInformation(
         48000: 1 << 3,
         64000: 1 << 2,
         88200: 1 << 1,
-        96000: 1
-    }
-    CHANNELS_BITS = {
-        1: 1 << 1,
-        2: 1
+        96000: 1,
     }
+    CHANNELS_BITS = {1: 1 << 1, 2: 1}
 
     @staticmethod
-    def from_bytes(data):
-        return AacMediaCodecInformation(*bitstruct.unpack(AacMediaCodecInformation.BIT_FIELDS, data))
+    def from_bytes(data: bytes) -> 'AacMediaCodecInformation':
+        object_type = data[0]
+        sampling_frequency = (data[1] << 4) | ((data[2] >> 4) & 0x0F)
+        channels = (data[2] >> 2) & 0x03
+        rfa = 0
+        vbr = (data[3] >> 7) & 0x01
+        bitrate = ((data[3] & 0x7F) << 16) | (data[4] << 8) | data[5]
+        return AacMediaCodecInformation(
+            object_type, sampling_frequency, channels, rfa, vbr, bitrate
+        )
 
     @classmethod
     def from_discrete_values(
-        cls,
-        object_type,
-        sampling_frequency,
-        channels,
-        vbr,
-        bitrate
+        cls, object_type, sampling_frequency, channels, vbr, bitrate
     ):
         return AacMediaCodecInformation(
-            object_type           = cls.OBJECT_TYPE_BITS[object_type],
-            sampling_frequency    = cls.SAMPLING_FREQUENCY_BITS[sampling_frequency],
-            channels              = cls.CHANNELS_BITS[channels],
-            vbr                   = vbr,
-            bitrate               = bitrate
+            object_type=cls.OBJECT_TYPE_BITS[object_type],
+            sampling_frequency=cls.SAMPLING_FREQUENCY_BITS[sampling_frequency],
+            channels=cls.CHANNELS_BITS[channels],
+            rfa=0,
+            vbr=vbr,
+            bitrate=bitrate,
         )
 
     @classmethod
-    def from_lists(
-        cls,
-        object_types,
-        sampling_frequencies,
-        channels,
-        vbr,
-        bitrate
-    ):
+    def from_lists(cls, object_types, sampling_frequencies, channels, vbr, bitrate):
         return AacMediaCodecInformation(
-            object_type           = sum(cls.OBJECT_TYPE_BITS[x] for x in object_types),
-            sampling_frequency    = sum(cls.SAMPLING_FREQUENCY_BITS[x] for x in sampling_frequencies),
-            channels              = sum(cls.CHANNELS_BITS[x] for x in channels),
-            vbr                   = vbr,
-            bitrate               = bitrate
+            object_type=sum(cls.OBJECT_TYPE_BITS[x] for x in object_types),
+            sampling_frequency=sum(
+                cls.SAMPLING_FREQUENCY_BITS[x] for x in sampling_frequencies
+            ),
+            channels=sum(cls.CHANNELS_BITS[x] for x in channels),
+            vbr=vbr,
+            bitrate=bitrate,
         )
 
-    def __bytes__(self):
-        return bitstruct.pack(self.BIT_FIELDS, *self)
+    def __bytes__(self) -> bytes:
+        return bytes(
+            [
+                self.object_type & 0xFF,
+                (self.sampling_frequency >> 4) & 0xFF,
+                (((self.sampling_frequency & 0x0F) << 4) | (self.channels << 2)) & 0xFF,
+                ((self.vbr << 7) | ((self.bitrate >> 16) & 0x7F)) & 0xFF,
+                ((self.bitrate >> 8) & 0xFF) & 0xFF,
+                self.bitrate & 0xFF,
+            ]
+        )
 
     def __str__(self):
-        object_types = ['MPEG_2_AAC_LC', 'MPEG_4_AAC_LC', 'MPEG_4_AAC_LTP', 'MPEG_4_AAC_SCALABLE', '[4]', '[5]', '[6]', '[7]']
+        object_types = [
+            'MPEG_2_AAC_LC',
+            'MPEG_4_AAC_LC',
+            'MPEG_4_AAC_LTP',
+            'MPEG_4_AAC_SCALABLE',
+            '[4]',
+            '[5]',
+            '[6]',
+            '[7]',
+        ]
         channels = [1, 2]
-        return '\n'.join([
-            'AacMediaCodecInformation(',
-            f'  object_type:        {",".join([str(x) for x in flags_to_list(self.object_type, object_types)])}',
-            f'  sampling_frequency: {",".join([str(x) for x in flags_to_list(self.sampling_frequency, MPEG_2_4_AAC_SAMPLING_FREQUENCIES)])}',
-            f'  channels:           {",".join([str(x) for x in flags_to_list(self.channels, channels)])}',
-            f'  vbr:                {self.vbr}',
-            f'  bitrate:            {self.bitrate}'
-            ')'
-        ])
+        # pylint: disable=line-too-long
+        return '\n'.join(
+            [
+                'AacMediaCodecInformation(',
+                f'  object_type:        {",".join([str(x) for x in flags_to_list(self.object_type, object_types)])}',
+                f'  sampling_frequency: {",".join([str(x) for x in flags_to_list(self.sampling_frequency, MPEG_2_4_AAC_SAMPLING_FREQUENCIES)])}',
+                f'  channels:           {",".join([str(x) for x in flags_to_list(self.channels, channels)])}',
+                f'  vbr:                {self.vbr}',
+                f'  bitrate:            {self.bitrate}' ')',
+            ]
+        )
 
 
 # -----------------------------------------------------------------------------
@@ -418,37 +486,34 @@ class VendorSpecificMediaCodecInformation:
 
     def __init__(self, vendor_id, codec_id, value):
         self.vendor_id = vendor_id
-        self.codec_id  = codec_id
-        self.value     = value
+        self.codec_id = codec_id
+        self.value = value
 
     def __bytes__(self):
         return struct.pack('<IH', self.vendor_id, self.codec_id, self.value)
 
     def __str__(self):
-        return '\n'.join([
-            'VendorSpecificMediaCodecInformation(',
-            f'  vendor_id: {self.vendor_id:08X} ({name_or_number(COMPANY_IDENTIFIERS, self.vendor_id & 0xFFFF)})',
-            f'  codec_id:  {self.codec_id:04X}',
-            f'  value:     {self.value.hex()}'
-            ')'
-        ])
+        # pylint: disable=line-too-long
+        return '\n'.join(
+            [
+                'VendorSpecificMediaCodecInformation(',
+                f'  vendor_id: {self.vendor_id:08X} ({name_or_number(COMPANY_IDENTIFIERS, self.vendor_id & 0xFFFF)})',
+                f'  codec_id:  {self.codec_id:04X}',
+                f'  value:     {self.value.hex()}' ')',
+            ]
+        )
 
 
 # -----------------------------------------------------------------------------
 class SbcFrame:
     def __init__(
-        self,
-        sampling_frequency,
-        block_count,
-        channel_mode,
-        subband_count,
-        payload
+        self, sampling_frequency, block_count, channel_mode, subband_count, payload
     ):
         self.sampling_frequency = sampling_frequency
-        self.block_count        = block_count
-        self.channel_mode       = channel_mode
-        self.subband_count      = subband_count
-        self.payload            = payload
+        self.block_count = block_count
+        self.channel_mode = channel_mode
+        self.subband_count = subband_count
+        self.payload = payload
 
     @property
     def sample_count(self):
@@ -463,7 +528,13 @@ class SbcFrame:
         return self.sample_count / self.sampling_frequency
 
     def __str__(self):
-        return f'SBC(sf={self.sampling_frequency},cm={self.channel_mode},br={self.bitrate},sc={self.sample_count},size={len(self.payload)})'
+        return (
+            f'SBC(sf={self.sampling_frequency},'
+            f'cm={self.channel_mode},'
+            f'br={self.bitrate},'
+            f'sc={self.sample_count},'
+            f'size={len(self.payload)})'
+        )
 
 
 # -----------------------------------------------------------------------------
@@ -487,24 +558,30 @@ class SbcParser:
 
                 # Extract some of the header fields
                 sampling_frequency = SBC_SAMPLING_FREQUENCIES[(header[1] >> 6) & 3]
-                blocks             = 4 * (1 + ((header[1] >> 4) & 3))
-                channel_mode       = (header[1] >> 2) & 3
-                channels           = 1 if channel_mode == SBC_MONO_CHANNEL_MODE else 2
-                subbands           = 8 if ((header[1]) & 1) else 4
-                bitpool            = header[2]
+                blocks = 4 * (1 + ((header[1] >> 4) & 3))
+                channel_mode = (header[1] >> 2) & 3
+                channels = 1 if channel_mode == SBC_MONO_CHANNEL_MODE else 2
+                subbands = 8 if ((header[1]) & 1) else 4
+                bitpool = header[2]
 
                 # Compute the frame length
                 frame_length = 4 + (4 * subbands * channels) // 8
                 if channel_mode in (SBC_MONO_CHANNEL_MODE, SBC_DUAL_CHANNEL_MODE):
                     frame_length += (blocks * channels * bitpool) // 8
                 else:
-                    frame_length += ((1 if channel_mode == SBC_JOINT_STEREO_CHANNEL_MODE else 0) * subbands + blocks * bitpool) // 8
+                    frame_length += (
+                        (1 if channel_mode == SBC_JOINT_STEREO_CHANNEL_MODE else 0)
+                        * subbands
+                        + blocks * bitpool
+                    ) // 8
 
                 # Read the rest of the frame
                 payload = header + await self.read(frame_length - 4)
 
                 # Emit the next frame
-                yield SbcFrame(sampling_frequency, blocks, channel_mode, subbands, payload)
+                yield SbcFrame(
+                    sampling_frequency, blocks, channel_mode, subbands, payload
+                )
 
         return generate_frames()
 
@@ -512,19 +589,20 @@ class SbcParser:
 # -----------------------------------------------------------------------------
 class SbcPacketSource:
     def __init__(self, read, mtu, codec_capabilities):
-        self.read               = read
-        self.mtu                = mtu
+        self.read = read
+        self.mtu = mtu
         self.codec_capabilities = codec_capabilities
 
     @property
     def packets(self):
         async def generate_packets():
+            # pylint: disable=import-outside-toplevel
             from .avdtp import MediaPacket  # Import here to avoid a circular reference
 
             sequence_number = 0
-            timestamp       = 0
-            frames          = []
-            frames_size     = 0
+            timestamp = 0
+            frames = []
+            frames_size = 0
             max_rtp_payload = self.mtu - 12 - 1
 
             # NOTE: this doesn't support frame fragments
@@ -532,18 +610,25 @@ class SbcPacketSource:
             async for frame in sbc_parser.frames:
                 print(frame)
 
-                if frames_size + len(frame.payload) > max_rtp_payload or len(frames) == 16:
+                if (
+                    frames_size + len(frame.payload) > max_rtp_payload
+                    or len(frames) == 16
+                ):
                     # Need to flush what has been accumulated so far
 
                     # Emit a packet
-                    sbc_payload = bytes([len(frames)]) + b''.join([frame.payload for frame in frames])
-                    packet = MediaPacket(2, 0, 0, 0, sequence_number, timestamp, 0, [], 96, sbc_payload)
+                    sbc_payload = bytes([len(frames)]) + b''.join(
+                        [frame.payload for frame in frames]
+                    )
+                    packet = MediaPacket(
+                        2, 0, 0, 0, sequence_number, timestamp, 0, [], 96, sbc_payload
+                    )
                     packet.timestamp_seconds = timestamp / frame.sampling_frequency
                     yield packet
 
                     # Prepare for next packets
                     sequence_number += 1
-                    timestamp += sum([frame.sample_count for frame in frames])
+                    timestamp += sum((frame.sample_count for frame in frames))
                     frames = [frame]
                     frames_size = len(frame.payload)
                 else:

bumble/att.py

@@ -22,15 +22,25 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
-from colors import color
+from __future__ import annotations
+import functools
+import struct
 from pyee import EventEmitter
+from typing import Dict, Type, TYPE_CHECKING
 
-from .core import *
-from .hci import *
+from bumble.core import UUID, name_or_number, get_dict_key_by_value, ProtocolError
+from bumble.hci import HCI_Object, key_with_value, HCI_Constant
+from bumble.colors import color
+
+if TYPE_CHECKING:
+    from bumble.device import Connection
 
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+# pylint: disable=line-too-long
+
 ATT_CID = 0x04
 
 ATT_ERROR_RESPONSE              = 0x01
@@ -163,30 +173,30 @@ ATT_ERROR_NAMES = {
 ATT_DEFAULT_MTU = 23
 
 HANDLE_FIELD_SPEC    = {'size': 2, 'mapper': lambda x: f'0x{x:04X}'}
-UUID_2_16_FIELD_SPEC = lambda x, y: UUID.parse_uuid(x, y)    # noqa: E731
+# pylint: disable-next=unnecessary-lambda-assignment,unnecessary-lambda
+UUID_2_16_FIELD_SPEC = lambda x, y: UUID.parse_uuid(x, y)
+# pylint: disable-next=unnecessary-lambda-assignment,unnecessary-lambda
 UUID_2_FIELD_SPEC    = lambda x, y: UUID.parse_uuid_2(x, y)  # noqa: E731
 
-
-# -----------------------------------------------------------------------------
-# Utils
-# -----------------------------------------------------------------------------
-def key_with_value(dictionary, target_value):
-    for key, value in dictionary.items():
-        if value == target_value:
-            return key
-    return None
-
+# fmt: on
+# pylint: enable=line-too-long
+# pylint: disable=invalid-name
 
 # -----------------------------------------------------------------------------
 # Exceptions
 # -----------------------------------------------------------------------------
-class ATT_Error(Exception):
-    def __init__(self, error_code, att_handle=0x0000):
-        self.error_code = error_code
+class ATT_Error(ProtocolError):
+    def __init__(self, error_code, att_handle=0x0000, message=''):
+        super().__init__(
+            error_code,
+            error_namespace='att',
+            error_name=ATT_PDU.error_name(error_code),
+        )
         self.att_handle = att_handle
+        self.message = message
 
     def __str__(self):
-        return f'ATT_Error({ATT_PDU.error_name(self.error_code)})'
+        return f'ATT_Error(error={self.error_name}, handle={self.att_handle:04X}): {self.message}'
 
 
 # -----------------------------------------------------------------------------
@@ -196,8 +206,10 @@ class ATT_PDU:
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.3 ATTRIBUTE PDU
     '''
-    pdu_classes = {}
+
+    pdu_classes: Dict[int, Type[ATT_PDU]] = {}
     op_code = 0
+    name = None
 
     @staticmethod
     def from_bytes(pdu):
@@ -274,11 +286,13 @@ class ATT_PDU:
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('request_opcode_in_error',   {'size': 1, 'mapper': ATT_PDU.pdu_name}),
-    ('attribute_handle_in_error', HANDLE_FIELD_SPEC),
-    ('error_code',                {'size': 1, 'mapper': ATT_PDU.error_name})
-])
+@ATT_PDU.subclass(
+    [
+        ('request_opcode_in_error', {'size': 1, 'mapper': ATT_PDU.pdu_name}),
+        ('attribute_handle_in_error', HANDLE_FIELD_SPEC),
+        ('error_code', {'size': 1, 'mapper': ATT_PDU.error_name}),
+    ]
+)
 class ATT_Error_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.1.1 Error Response
@@ -286,9 +300,7 @@ class ATT_Error_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('client_rx_mtu', 2)
-])
+@ATT_PDU.subclass([('client_rx_mtu', 2)])
 class ATT_Exchange_MTU_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.2.1 Exchange MTU Request
@@ -296,9 +308,7 @@ class ATT_Exchange_MTU_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('server_rx_mtu', 2)
-])
+@ATT_PDU.subclass([('server_rx_mtu', 2)])
 class ATT_Exchange_MTU_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.2.2 Exchange MTU Response
@@ -306,10 +316,9 @@ class ATT_Exchange_MTU_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('starting_handle', HANDLE_FIELD_SPEC),
-    ('ending_handle',   HANDLE_FIELD_SPEC)
-])
+@ATT_PDU.subclass(
+    [('starting_handle', HANDLE_FIELD_SPEC), ('ending_handle', HANDLE_FIELD_SPEC)]
+)
 class ATT_Find_Information_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.3.1 Find Information Request
@@ -317,10 +326,7 @@ class ATT_Find_Information_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('format',           1),
-    ('information_data', '*')
-])
+@ATT_PDU.subclass([('format', 1), ('information_data', '*')])
 class ATT_Find_Information_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.3.2 Find Information Response
@@ -332,7 +338,7 @@ class ATT_Find_Information_Response(ATT_PDU):
         uuid_size = 2 if self.format == 1 else 16
         while offset + uuid_size <= len(self.information_data):
             handle = struct.unpack_from('<H', self.information_data, offset)[0]
-            uuid   = self.information_data[2 + offset:2 + offset + uuid_size]
+            uuid = self.information_data[2 + offset : 2 + offset + uuid_size]
             self.information.append((handle, uuid))
             offset += 2 + uuid_size
 
@@ -346,20 +352,33 @@ class ATT_Find_Information_Response(ATT_PDU):
 
     def __str__(self):
         result = color(self.name, 'yellow')
-        result += ':\n' + HCI_Object.format_fields(self.__dict__, [
-            ('format',       1),
-            ('information', {'mapper': lambda x: ', '.join([f'0x{handle:04X}:{uuid.hex()}' for handle, uuid in x])})
-        ], '  ')
+        result += ':\n' + HCI_Object.format_fields(
+            self.__dict__,
+            [
+                ('format', 1),
+                (
+                    'information',
+                    {
+                        'mapper': lambda x: ', '.join(
+                            [f'0x{handle:04X}:{uuid.hex()}' for handle, uuid in x]
+                        )
+                    },
+                ),
+            ],
+            '  ',
+        )
         return result
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('starting_handle', HANDLE_FIELD_SPEC),
-    ('ending_handle',   HANDLE_FIELD_SPEC),
-    ('attribute_type',  UUID_2_FIELD_SPEC),
-    ('attribute_value', '*')
-])
+@ATT_PDU.subclass(
+    [
+        ('starting_handle', HANDLE_FIELD_SPEC),
+        ('ending_handle', HANDLE_FIELD_SPEC),
+        ('attribute_type', UUID_2_FIELD_SPEC),
+        ('attribute_value', '*'),
+    ]
+)
 class ATT_Find_By_Type_Value_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.3.3 Find By Type Value Request
@@ -367,9 +386,7 @@ class ATT_Find_By_Type_Value_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('handles_information_list', '*')
-])
+@ATT_PDU.subclass([('handles_information_list', '*')])
 class ATT_Find_By_Type_Value_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.3.4 Find By Type Value Response
@@ -379,7 +396,9 @@ class ATT_Find_By_Type_Value_Response(ATT_PDU):
         self.handles_information = []
         offset = 0
         while offset + 4 <= len(self.handles_information_list):
-            found_attribute_handle, group_end_handle = struct.unpack_from('<HH', self.handles_information_list, offset)
+            found_attribute_handle, group_end_handle = struct.unpack_from(
+                '<HH', self.handles_information_list, offset
+            )
             self.handles_information.append((found_attribute_handle, group_end_handle))
             offset += 4
 
@@ -393,18 +412,34 @@ class ATT_Find_By_Type_Value_Response(ATT_PDU):
 
     def __str__(self):
         result = color(self.name, 'yellow')
-        result += ':\n' + HCI_Object.format_fields(self.__dict__, [
-            ('handles_information', {'mapper': lambda x: ', '.join([f'0x{handle1:04X}-0x{handle2:04X}' for handle1, handle2 in x])})
-        ], '  ')
+        result += ':\n' + HCI_Object.format_fields(
+            self.__dict__,
+            [
+                (
+                    'handles_information',
+                    {
+                        'mapper': lambda x: ', '.join(
+                            [
+                                f'0x{handle1:04X}-0x{handle2:04X}'
+                                for handle1, handle2 in x
+                            ]
+                        )
+                    },
+                )
+            ],
+            '  ',
+        )
         return result
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('starting_handle', HANDLE_FIELD_SPEC),
-    ('ending_handle',   HANDLE_FIELD_SPEC),
-    ('attribute_type',  UUID_2_16_FIELD_SPEC)
-])
+@ATT_PDU.subclass(
+    [
+        ('starting_handle', HANDLE_FIELD_SPEC),
+        ('ending_handle', HANDLE_FIELD_SPEC),
+        ('attribute_type', UUID_2_16_FIELD_SPEC),
+    ]
+)
 class ATT_Read_By_Type_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.1 Read By Type Request
@@ -412,10 +447,7 @@ class ATT_Read_By_Type_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('length',              1),
-    ('attribute_data_list', '*')
-])
+@ATT_PDU.subclass([('length', 1), ('attribute_data_list', '*')])
 class ATT_Read_By_Type_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.2 Read By Type Response
@@ -424,9 +456,15 @@ class ATT_Read_By_Type_Response(ATT_PDU):
     def parse_attribute_data_list(self):
         self.attributes = []
         offset = 0
-        while self.length != 0 and offset + self.length <= len(self.attribute_data_list):
-            attribute_handle, = struct.unpack_from('<H', self.attribute_data_list, offset)
-            attribute_value = self.attribute_data_list[offset + 2:offset + self.length]
+        while self.length != 0 and offset + self.length <= len(
+            self.attribute_data_list
+        ):
+            (attribute_handle,) = struct.unpack_from(
+                '<H', self.attribute_data_list, offset
+            )
+            attribute_value = self.attribute_data_list[
+                offset + 2 : offset + self.length
+            ]
             self.attributes.append((attribute_handle, attribute_value))
             offset += self.length
 
@@ -440,17 +478,26 @@ class ATT_Read_By_Type_Response(ATT_PDU):
 
     def __str__(self):
         result = color(self.name, 'yellow')
-        result += ':\n' + HCI_Object.format_fields(self.__dict__, [
-            ('length',     1),
-            ('attributes', {'mapper': lambda x: ', '.join([f'0x{handle:04X}:{value.hex()}' for handle, value in x])})
-        ], '  ')
+        result += ':\n' + HCI_Object.format_fields(
+            self.__dict__,
+            [
+                ('length', 1),
+                (
+                    'attributes',
+                    {
+                        'mapper': lambda x: ', '.join(
+                            [f'0x{handle:04X}:{value.hex()}' for handle, value in x]
+                        )
+                    },
+                ),
+            ],
+            '  ',
+        )
         return result
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC)
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC)])
 class ATT_Read_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.3 Read Request
@@ -458,9 +505,7 @@ class ATT_Read_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_value', '*')
-])
+@ATT_PDU.subclass([('attribute_value', '*')])
 class ATT_Read_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.4 Read Response
@@ -468,10 +513,7 @@ class ATT_Read_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('value_offset',     2)
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC), ('value_offset', 2)])
 class ATT_Read_Blob_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.5 Read Blob Request
@@ -479,9 +521,7 @@ class ATT_Read_Blob_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('part_attribute_value', '*')
-])
+@ATT_PDU.subclass([('part_attribute_value', '*')])
 class ATT_Read_Blob_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.6 Read Blob Response
@@ -489,9 +529,7 @@ class ATT_Read_Blob_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('set_of_handles', '*')
-])
+@ATT_PDU.subclass([('set_of_handles', '*')])
 class ATT_Read_Multiple_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.7 Read Multiple Request
@@ -499,9 +537,7 @@ class ATT_Read_Multiple_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('set_of_values', '*')
-])
+@ATT_PDU.subclass([('set_of_values', '*')])
 class ATT_Read_Multiple_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.8 Read Multiple Response
@@ -509,11 +545,13 @@ class ATT_Read_Multiple_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('starting_handle',      HANDLE_FIELD_SPEC),
-    ('ending_handle',        HANDLE_FIELD_SPEC),
-    ('attribute_group_type', UUID_2_16_FIELD_SPEC)
-])
+@ATT_PDU.subclass(
+    [
+        ('starting_handle', HANDLE_FIELD_SPEC),
+        ('ending_handle', HANDLE_FIELD_SPEC),
+        ('attribute_group_type', UUID_2_16_FIELD_SPEC),
+    ]
+)
 class ATT_Read_By_Group_Type_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.9 Read by Group Type Request
@@ -521,10 +559,7 @@ class ATT_Read_By_Group_Type_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('length',              1),
-    ('attribute_data_list', '*')
-])
+@ATT_PDU.subclass([('length', 1), ('attribute_data_list', '*')])
 class ATT_Read_By_Group_Type_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.4.10 Read by Group Type Response
@@ -533,10 +568,18 @@ class ATT_Read_By_Group_Type_Response(ATT_PDU):
     def parse_attribute_data_list(self):
         self.attributes = []
         offset = 0
-        while self.length != 0 and offset + self.length <= len(self.attribute_data_list):
-            attribute_handle, end_group_handle = struct.unpack_from('<HH', self.attribute_data_list, offset)
-            attribute_value = self.attribute_data_list[offset + 4:offset + self.length]
-            self.attributes.append((attribute_handle, end_group_handle, attribute_value))
+        while self.length != 0 and offset + self.length <= len(
+            self.attribute_data_list
+        ):
+            attribute_handle, end_group_handle = struct.unpack_from(
+                '<HH', self.attribute_data_list, offset
+            )
+            attribute_value = self.attribute_data_list[
+                offset + 4 : offset + self.length
+            ]
+            self.attributes.append(
+                (attribute_handle, end_group_handle, attribute_value)
+            )
             offset += self.length
 
     def __init__(self, *args, **kwargs):
@@ -549,18 +592,29 @@ class ATT_Read_By_Group_Type_Response(ATT_PDU):
 
     def __str__(self):
         result = color(self.name, 'yellow')
-        result += ':\n' + HCI_Object.format_fields(self.__dict__, [
-            ('length',     1),
-            ('attributes', {'mapper': lambda x: ', '.join([f'0x{handle:04X}-0x{end:04X}:{value.hex()}' for handle, end, value in x])})
-        ], '  ')
+        result += ':\n' + HCI_Object.format_fields(
+            self.__dict__,
+            [
+                ('length', 1),
+                (
+                    'attributes',
+                    {
+                        'mapper': lambda x: ', '.join(
+                            [
+                                f'0x{handle:04X}-0x{end:04X}:{value.hex()}'
+                                for handle, end, value in x
+                            ]
+                        )
+                    },
+                ),
+            ],
+            '  ',
+        )
         return result
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('attribute_value',  '*')
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC), ('attribute_value', '*')])
 class ATT_Write_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.5.1 Write Request
@@ -576,10 +630,7 @@ class ATT_Write_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('attribute_value',  '*')
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC), ('attribute_value', '*')])
 class ATT_Write_Command(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.5.3 Write Command
@@ -587,11 +638,13 @@ class ATT_Write_Command(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('attribute_value',  '*')
-    # ('authentication_signature', 'TODO')
-])
+@ATT_PDU.subclass(
+    [
+        ('attribute_handle', HANDLE_FIELD_SPEC),
+        ('attribute_value', '*')
+        # ('authentication_signature', 'TODO')
+    ]
+)
 class ATT_Signed_Write_Command(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.5.4 Signed Write Command
@@ -599,11 +652,13 @@ class ATT_Signed_Write_Command(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle',     HANDLE_FIELD_SPEC),
-    ('value_offset',         2),
-    ('part_attribute_value', '*')
-])
+@ATT_PDU.subclass(
+    [
+        ('attribute_handle', HANDLE_FIELD_SPEC),
+        ('value_offset', 2),
+        ('part_attribute_value', '*'),
+    ]
+)
 class ATT_Prepare_Write_Request(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.6.1 Prepare Write Request
@@ -611,11 +666,13 @@ class ATT_Prepare_Write_Request(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle',     HANDLE_FIELD_SPEC),
-    ('value_offset',         2),
-    ('part_attribute_value', '*')
-])
+@ATT_PDU.subclass(
+    [
+        ('attribute_handle', HANDLE_FIELD_SPEC),
+        ('value_offset', 2),
+        ('part_attribute_value', '*'),
+    ]
+)
 class ATT_Prepare_Write_Response(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.6.2 Prepare Write Response
@@ -639,10 +696,7 @@ class ATT_Execute_Write_Response(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('attribute_value',  '*')
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC), ('attribute_value', '*')])
 class ATT_Handle_Value_Notification(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.7.1 Handle Value Notification
@@ -650,10 +704,7 @@ class ATT_Handle_Value_Notification(ATT_PDU):
 
 
 # -----------------------------------------------------------------------------
-@ATT_PDU.subclass([
-    ('attribute_handle', HANDLE_FIELD_SPEC),
-    ('attribute_value',  '*')
-])
+@ATT_PDU.subclass([('attribute_handle', HANDLE_FIELD_SPEC), ('attribute_value', '*')])
 class ATT_Handle_Value_Indication(ATT_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part F - 3.4.7.2 Handle Value Indication
@@ -671,58 +722,143 @@ class ATT_Handle_Value_Confirmation(ATT_PDU):
 # -----------------------------------------------------------------------------
 class Attribute(EventEmitter):
     # Permission flags
-    READABLE                      = 0x01
-    WRITEABLE                     = 0x02
-    READ_REQUIRES_ENCRYPTION      = 0x04
-    WRITE_REQUIRES_ENCRYPTION     = 0x08
-    READ_REQUIRES_AUTHENTICATION  = 0x10
+    READABLE = 0x01
+    WRITEABLE = 0x02
+    READ_REQUIRES_ENCRYPTION = 0x04
+    WRITE_REQUIRES_ENCRYPTION = 0x08
+    READ_REQUIRES_AUTHENTICATION = 0x10
     WRITE_REQUIRES_AUTHENTICATION = 0x20
-    READ_REQUIRES_AUTHORIZATION   = 0x40
-    WRITE_REQUIRES_AUTHORIZATION  = 0x80
+    READ_REQUIRES_AUTHORIZATION = 0x40
+    WRITE_REQUIRES_AUTHORIZATION = 0x80
 
-    def __init__(self, attribute_type, permissions, value = b''):
+    PERMISSION_NAMES = {
+        READABLE: 'READABLE',
+        WRITEABLE: 'WRITEABLE',
+        READ_REQUIRES_ENCRYPTION: 'READ_REQUIRES_ENCRYPTION',
+        WRITE_REQUIRES_ENCRYPTION: 'WRITE_REQUIRES_ENCRYPTION',
+        READ_REQUIRES_AUTHENTICATION: 'READ_REQUIRES_AUTHENTICATION',
+        WRITE_REQUIRES_AUTHENTICATION: 'WRITE_REQUIRES_AUTHENTICATION',
+        READ_REQUIRES_AUTHORIZATION: 'READ_REQUIRES_AUTHORIZATION',
+        WRITE_REQUIRES_AUTHORIZATION: 'WRITE_REQUIRES_AUTHORIZATION',
+    }
+
+    @staticmethod
+    def string_to_permissions(permissions_str: str):
+        try:
+            return functools.reduce(
+                lambda x, y: x | get_dict_key_by_value(Attribute.PERMISSION_NAMES, y),
+                permissions_str.split(","),
+                0,
+            )
+        except TypeError as exc:
+            raise TypeError(
+                f"Attribute::permissions error:\nExpected a string containing any of the keys, separated by commas: {','.join(Attribute.PERMISSION_NAMES.values())}\nGot: {permissions_str}"
+            ) from exc
+
+    def __init__(self, attribute_type, permissions, value=b''):
         EventEmitter.__init__(self)
-        self.handle           = 0
+        self.handle = 0
         self.end_group_handle = 0
-        self.permissions      = permissions
+        if isinstance(permissions, str):
+            self.permissions = self.string_to_permissions(permissions)
+        else:
+            self.permissions = permissions
 
         # Convert the type to a UUID object if it isn't already
-        if type(attribute_type) is str:
+        if isinstance(attribute_type, str):
             self.type = UUID(attribute_type)
-        elif type(attribute_type) is bytes:
+        elif isinstance(attribute_type, bytes):
             self.type = UUID.from_bytes(attribute_type)
         else:
             self.type = attribute_type
 
         # Convert the value to a byte array
-        if type(value) is str:
+        if isinstance(value, str):
             self.value = bytes(value, 'utf-8')
         else:
             self.value = value
 
-    def read_value(self, connection):
+    def encode_value(self, value):
+        return value
+
+    def decode_value(self, value_bytes):
+        return value_bytes
+
+    def read_value(self, connection: Connection):
+        if (
+            self.permissions & self.READ_REQUIRES_ENCRYPTION
+        ) and not connection.encryption:
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_ENCRYPTION_ERROR, att_handle=self.handle
+            )
+        if (
+            self.permissions & self.READ_REQUIRES_AUTHENTICATION
+        ) and not connection.authenticated:
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_AUTHENTICATION_ERROR, att_handle=self.handle
+            )
+        if self.permissions & self.READ_REQUIRES_AUTHORIZATION:
+            # TODO: handle authorization better
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_AUTHORIZATION_ERROR, att_handle=self.handle
+            )
+
         if read := getattr(self.value, 'read', None):
             try:
-                return read(connection)
+                value = read(connection)  # pylint: disable=not-callable
             except ATT_Error as error:
-                raise ATT_Error(error_code=error.error_code, att_handle=self.handle)
+                raise ATT_Error(
+                    error_code=error.error_code, att_handle=self.handle
+                ) from error
         else:
-            return self.value
+            value = self.value
+
+        return self.encode_value(value)
+
+    def write_value(self, connection: Connection, value_bytes):
+        if (
+            self.permissions & self.WRITE_REQUIRES_ENCRYPTION
+        ) and not connection.encryption:
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_ENCRYPTION_ERROR, att_handle=self.handle
+            )
+        if (
+            self.permissions & self.WRITE_REQUIRES_AUTHENTICATION
+        ) and not connection.authenticated:
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_AUTHENTICATION_ERROR, att_handle=self.handle
+            )
+        if self.permissions & self.WRITE_REQUIRES_AUTHORIZATION:
+            # TODO: handle authorization better
+            raise ATT_Error(
+                error_code=ATT_INSUFFICIENT_AUTHORIZATION_ERROR, att_handle=self.handle
+            )
+
+        value = self.decode_value(value_bytes)
 
-    def write_value(self, connection, value):
         if write := getattr(self.value, 'write', None):
             try:
-                write(connection, value)
+                write(connection, value)  # pylint: disable=not-callable
             except ATT_Error as error:
-                raise ATT_Error(error_code=error.error_code, att_handle=self.handle)
+                raise ATT_Error(
+                    error_code=error.error_code, att_handle=self.handle
+                ) from error
         else:
             self.value = value
 
         self.emit('write', connection, value)
 
     def __repr__(self):
-        if len(self.value) > 0:
+        if isinstance(self.value, bytes):
+            value_str = self.value.hex()
+        else:
+            value_str = str(self.value)
+        if value_str:
             value_string = f', value={self.value.hex()}'
         else:
             value_string = ''
-        return f'Attribute(handle=0x{self.handle:04X}, type={self.type}, permissions={self.permissions}{value_string})'
+        return (
+            f'Attribute(handle=0x{self.handle:04X}, '
+            f'type={self.type}, '
+            f'permissions={self.permissions}{value_string})'
+        )

bumble/bridge.py

@@ -30,10 +30,10 @@ logger = logging.getLogger(__name__)
 class HCI_Bridge:
     class Forwarder:
         def __init__(self, hci_sink, sender_hci_sink, packet_filter, trace):
-            self.hci_sink        = hci_sink
+            self.hci_sink = hci_sink
             self.sender_hci_sink = sender_hci_sink
-            self.packet_filter   = packet_filter
-            self.trace           = trace
+            self.packet_filter = packet_filter
+            self.trace = trace
 
         def on_packet(self, packet):
             # Convert the packet bytes to an object
@@ -61,15 +61,15 @@ class HCI_Bridge:
         hci_host_sink,
         hci_controller_source,
         hci_controller_sink,
-        host_to_controller_filter = None,
-        controller_to_host_filter = None
+        host_to_controller_filter=None,
+        controller_to_host_filter=None,
     ):
         tracer = PacketTracer(emit_message=logger.info)
         host_to_controller_forwarder = HCI_Bridge.Forwarder(
             hci_controller_sink,
             hci_host_sink,
             host_to_controller_filter,
-            lambda packet: tracer.trace(packet, 0)
+            lambda packet: tracer.trace(packet, 0),
         )
         hci_host_source.set_packet_sink(host_to_controller_forwarder)
 
@@ -77,6 +77,6 @@ class HCI_Bridge:
             hci_host_sink,
             hci_controller_sink,
             controller_to_host_filter,
-            lambda packet: tracer.trace(packet, 1)
+            lambda packet: tracer.trace(packet, 1),
         )
         hci_controller_source.set_packet_sink(controller_to_host_forwarder)

bumble/colors.py

@@ -0,0 +1,103 @@
+# Copyright (c) 2012 Giorgos Verigakis <verigak@gmail.com>
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from functools import partial
+from typing import List, Optional, Union
+
+
+# ANSI color names. There is also a "default"
+COLORS = ('black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white')
+
+# ANSI style names
+STYLES = (
+    'none',
+    'bold',
+    'faint',
+    'italic',
+    'underline',
+    'blink',
+    'blink2',
+    'negative',
+    'concealed',
+    'crossed',
+)
+
+
+ColorSpec = Union[str, int]
+
+
+def _join(*values: ColorSpec) -> str:
+    return ';'.join(str(v) for v in values)
+
+
+def _color_code(spec: ColorSpec, base: int) -> str:
+    if isinstance(spec, str):
+        spec = spec.strip().lower()
+
+    if spec == 'default':
+        return _join(base + 9)
+    elif spec in COLORS:
+        return _join(base + COLORS.index(spec))
+    elif isinstance(spec, int) and 0 <= spec <= 255:
+        return _join(base + 8, 5, spec)
+    else:
+        raise ValueError('Invalid color spec "%s"' % spec)
+
+
+def color(
+    s: str,
+    fg: Optional[ColorSpec] = None,
+    bg: Optional[ColorSpec] = None,
+    style: Optional[str] = None,
+) -> str:
+    codes: List[ColorSpec] = []
+
+    if fg:
+        codes.append(_color_code(fg, 30))
+    if bg:
+        codes.append(_color_code(bg, 40))
+    if style:
+        for style_part in style.split('+'):
+            if style_part in STYLES:
+                codes.append(STYLES.index(style_part))
+            else:
+                raise ValueError('Invalid style "%s"' % style_part)
+
+    if codes:
+        return '\x1b[{0}m{1}\x1b[0m'.format(_join(*codes), s)
+    else:
+        return s
+
+
+# Foreground color shortcuts
+black = partial(color, fg='black')
+red = partial(color, fg='red')
+green = partial(color, fg='green')
+yellow = partial(color, fg='yellow')
+blue = partial(color, fg='blue')
+magenta = partial(color, fg='magenta')
+cyan = partial(color, fg='cyan')
+white = partial(color, fg='white')
+
+# Style shortcuts
+bold = partial(color, style='bold')
+none = partial(color, style='none')
+faint = partial(color, style='faint')
+italic = partial(color, style='italic')
+underline = partial(color, style='underline')
+blink = partial(color, style='blink')
+blink2 = partial(color, style='blink2')
+negative = partial(color, style='negative')
+concealed = partial(color, style='concealed')
+crossed = partial(color, style='crossed')

bumble/company_ids.py

@@ -17,6 +17,7 @@
 #  the `generate_company_id_list.py` script
 # -----------------------------------------------------------------------------
 
+# pylint: disable=line-too-long
 COMPANY_IDENTIFIERS = {
     0x0000: "Ericsson Technology Licensing",
     0x0001: "Nokia Mobile Phones",
@@ -196,28 +197,28 @@ COMPANY_IDENTIFIERS = {
     0x00AF: "Cinetix",
     0x00B0: "Passif Semiconductor Corp",
     0x00B1: "Saris Cycling Group, Inc",
-    0x00B2: "​Bekey A/S",
-    0x00B3: "​Clarinox Technologies Pty. Ltd.",
-    0x00B4: "​BDE Technology Co., Ltd.",
+    0x00B2: "Bekey A/S",
+    0x00B3: "Clarinox Technologies Pty. Ltd.",
+    0x00B4: "BDE Technology Co., Ltd.",
     0x00B5: "Swirl Networks",
-    0x00B6: "​Meso international",
-    0x00B7: "​TreLab Ltd",
-    0x00B8: "​Qualcomm Innovation Center, Inc. (QuIC)",
-    0x00B9: "​​Johnson Controls, Inc.",
-    0x00BA: "​Starkey Laboratories Inc.",
-    0x00BB: "​​S-Power Electronics Limited",
-    0x00BC: "​​Ace Sensor Inc",
-    0x00BD: "​​Aplix Corporation",
-    0x00BE: "​​AAMP of America",
-    0x00BF: "​​Stalmart Technology Limited",
-    0x00C0: "​​AMICCOM Electronics Corporation",
-    0x00C1: "​​Shenzhen Excelsecu Data Technology Co.,Ltd",
-    0x00C2: "​​Geneq Inc.",
-    0x00C3: "​​adidas AG",
-    0x00C4: "​​LG Electronics​",
-    0x00C5: "​Onset Computer Corporation",
-    0x00C6: "​Selfly BV",
-    0x00C7: "​Quuppa Oy.",
+    0x00B6: "Meso international",
+    0x00B7: "TreLab Ltd",
+    0x00B8: "Qualcomm Innovation Center, Inc. (QuIC)",
+    0x00B9: "Johnson Controls, Inc.",
+    0x00BA: "Starkey Laboratories Inc.",
+    0x00BB: "S-Power Electronics Limited",
+    0x00BC: "Ace Sensor Inc",
+    0x00BD: "Aplix Corporation",
+    0x00BE: "AAMP of America",
+    0x00BF: "Stalmart Technology Limited",
+    0x00C0: "AMICCOM Electronics Corporation",
+    0x00C1: "Shenzhen Excelsecu Data Technology Co.,Ltd",
+    0x00C2: "Geneq Inc.",
+    0x00C3: "adidas AG",
+    0x00C4: "LG Electronics",
+    0x00C5: "Onset Computer Corporation",
+    0x00C6: "Selfly BV",
+    0x00C7: "Quuppa Oy.",
     0x00C8: "GeLo Inc",
     0x00C9: "Evluma",
     0x00CA: "MC10",
@@ -249,10 +250,10 @@ COMPANY_IDENTIFIERS = {
     0x00E4: "Laird Connectivity, Inc. formerly L.S. Research Inc.",
     0x00E5: "Eden Software Consultants Ltd.",
     0x00E6: "Freshtemp",
-    0x00E7: "​KS Technologies",
-    0x00E8: "​ACTS Technologies",
-    0x00E9: "​Vtrack Systems",
-    0x00EA: "​Nielsen-Kellerman Company",
+    0x00E7: "KS Technologies",
+    0x00E8: "ACTS Technologies",
+    0x00E9: "Vtrack Systems",
+    0x00EA: "Nielsen-Kellerman Company",
     0x00EB: "Server Technology Inc.",
     0x00EC: "BioResearch Associates",
     0x00ED: "Jolly Logic, LLC",
@@ -2704,5 +2705,5 @@ COMPANY_IDENTIFIERS = {
     0x0A7C: "WAFERLOCK",
     0x0A7D: "Freedman Electronics Pty Ltd",
     0x0A7E: "Keba AG",
-    0x0A7F: "Intuity Medical"
-}
+    0x0A7F: "Intuity Medical",
+}

bumble/core.py

@@ -15,7 +15,9 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
 import struct
+from typing import List, Optional, Tuple, Union, cast
 
 from .company_ids import COMPANY_IDENTIFIERS
 
@@ -23,6 +25,8 @@ from .company_ids import COMPANY_IDENTIFIERS
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+
 BT_CENTRAL_ROLE    = 0
 BT_PERIPHERAL_ROLE = 1
 
@@ -30,6 +34,9 @@ BT_BR_EDR_TRANSPORT = 0
 BT_LE_TRANSPORT     = 1
 
 
+# fmt: on
+
+
 # -----------------------------------------------------------------------------
 # Utils
 # -----------------------------------------------------------------------------
@@ -58,17 +65,25 @@ def padded_bytes(buffer, size):
     return buffer + bytes(padding_size)
 
 
+def get_dict_key_by_value(dictionary, value):
+    for key, val in dictionary.items():
+        if val == value:
+            return key
+    return None
+
+
 # -----------------------------------------------------------------------------
 # Exceptions
 # -----------------------------------------------------------------------------
 class BaseError(Exception):
-    """ Base class for errors with an error code, error name and namespace"""
+    """Base class for errors with an error code, error name and namespace"""
+
     def __init__(self, error_code, error_namespace='', error_name='', details=''):
         super().__init__()
-        self.error_code      = error_code
+        self.error_code = error_code
         self.error_namespace = error_namespace
-        self.error_name      = error_name
-        self.details         = details
+        self.error_name = error_name
+        self.details = details
 
     def __str__(self):
         if self.error_namespace:
@@ -84,22 +99,40 @@ class BaseError(Exception):
 
 
 class ProtocolError(BaseError):
-    """ Protocol Error """
+    """Protocol Error"""
 
 
-class TimeoutError(Exception):
-    """ Timeout Error """
+class TimeoutError(Exception):  # pylint: disable=redefined-builtin
+    """Timeout Error"""
+
+
+class CommandTimeoutError(Exception):
+    """Command Timeout Error"""
 
 
 class InvalidStateError(Exception):
-    """ Invalid State Error """
+    """Invalid State Error"""
 
 
-class ConnectionError(BaseError):
-    """ Connection Error """
-    FAILURE            = 0x01
+class ConnectionError(BaseError):  # pylint: disable=redefined-builtin
+    """Connection Error"""
+
+    FAILURE = 0x01
     CONNECTION_REFUSED = 0x02
 
+    def __init__(
+        self,
+        error_code,
+        transport,
+        peer_address,
+        error_namespace='',
+        error_name='',
+        details='',
+    ):
+        super().__init__(error_code, error_namespace, error_name, details)
+        self.transport = transport
+        self.peer_address = peer_address
+
 
 # -----------------------------------------------------------------------------
 # UUID
@@ -111,27 +144,37 @@ class ConnectionError(BaseError):
 class UUID:
     '''
     See Bluetooth spec Vol 3, Part B - 2.5.1 UUID
-    '''
-    BASE_UUID = bytes.fromhex('00001000800000805F9B34FB')
-    UUIDS = []  # Registry of all instances created
 
-    def __init__(self, uuid_str_or_int, name = None):
-        if type(uuid_str_or_int) is int:
+    Note that this class expects and works in little-endian byte-order throughout.
+    The exception is when interacting with strings, which are in big-endian byte-order.
+    '''
+
+    BASE_UUID = bytes.fromhex('00001000800000805F9B34FB')[::-1]  # little-endian
+    UUIDS: List[UUID] = []  # Registry of all instances created
+
+    def __init__(self, uuid_str_or_int, name=None):
+        if isinstance(uuid_str_or_int, int):
             self.uuid_bytes = struct.pack('<H', uuid_str_or_int)
         else:
             if len(uuid_str_or_int) == 36:
-                if uuid_str_or_int[8] != '-' or uuid_str_or_int[13] != '-' or uuid_str_or_int[18] != '-' or uuid_str_or_int[23] != '-':
+                if (
+                    uuid_str_or_int[8] != '-'
+                    or uuid_str_or_int[13] != '-'
+                    or uuid_str_or_int[18] != '-'
+                    or uuid_str_or_int[23] != '-'
+                ):
                     raise ValueError('invalid UUID format')
                 uuid_str = uuid_str_or_int.replace('-', '')
             else:
                 uuid_str = uuid_str_or_int
             if len(uuid_str) != 32 and len(uuid_str) != 8 and len(uuid_str) != 4:
-                raise ValueError('invalid UUID format')
+                raise ValueError(f"invalid UUID format: {uuid_str}")
             self.uuid_bytes = bytes(reversed(bytes.fromhex(uuid_str)))
         self.name = name
 
     def register(self):
-        # Register this object in the class registry, and update the entry's name if it wasn't set already
+        # Register this object in the class registry, and update the entry's name if
+        # it wasn't set already
         for uuid in self.UUIDS:
             if self == uuid:
                 if uuid.name is None:
@@ -142,39 +185,47 @@ class UUID:
         return self
 
     @classmethod
-    def from_bytes(cls, uuid_bytes, name = None):
-        if len(uuid_bytes) in {2, 4, 16}:
+    def from_bytes(cls, uuid_bytes: bytes, name: Optional[str] = None) -> UUID:
+        if len(uuid_bytes) in (2, 4, 16):
             self = cls.__new__(cls)
             self.uuid_bytes = uuid_bytes
             self.name = name
 
             return self.register()
-        else:
-            raise ValueError('only 2, 4 and 16 bytes are allowed')
+
+        raise ValueError('only 2, 4 and 16 bytes are allowed')
 
     @classmethod
-    def from_16_bits(cls, uuid_16, name = None):
+    def from_16_bits(cls, uuid_16, name=None):
         return cls.from_bytes(struct.pack('<H', uuid_16), name)
 
     @classmethod
-    def from_32_bits(cls, uuid_32, name = None):
+    def from_32_bits(cls, uuid_32, name=None):
         return cls.from_bytes(struct.pack('<I', uuid_32), name)
 
     @classmethod
-    def parse_uuid(cls, bytes, offset):
-        return len(bytes), cls.from_bytes(bytes[offset:])
+    def parse_uuid(cls, uuid_as_bytes, offset):
+        return len(uuid_as_bytes), cls.from_bytes(uuid_as_bytes[offset:])
 
     @classmethod
-    def parse_uuid_2(cls, bytes, offset):
-        return offset + 2, cls.from_bytes(bytes[offset:offset + 2])
+    def parse_uuid_2(cls, uuid_as_bytes, offset):
+        return offset + 2, cls.from_bytes(uuid_as_bytes[offset : offset + 2])
 
-    def to_bytes(self, force_128 = False):
-        if len(self.uuid_bytes) == 16 or not force_128:
+    def to_bytes(self, force_128=False):
+        '''
+        Serialize UUID in little-endian byte-order
+        '''
+        if not force_128:
             return self.uuid_bytes
+
+        if len(self.uuid_bytes) == 2:
+            return self.BASE_UUID + self.uuid_bytes + bytes([0, 0])
         elif len(self.uuid_bytes) == 4:
-            return self.uuid_bytes + UUID.BASE_UUID
+            return self.BASE_UUID + self.uuid_bytes
+        elif len(self.uuid_bytes) == 16:
+            return self.uuid_bytes
         else:
-            return self.uuid_bytes + bytes([0, 0]) + UUID.BASE_UUID
+            assert False, "unreachable"
 
     def to_pdu_bytes(self):
         '''
@@ -183,27 +234,30 @@ class UUID:
         "All 32-bit Attribute UUIDs shall be converted to 128-bit UUIDs when the
          Attribute UUID is contained in an ATT PDU."
         '''
-        return self.to_bytes(force_128 = (len(self.uuid_bytes) == 4))
+        return self.to_bytes(force_128=(len(self.uuid_bytes) == 4))
 
-    def to_hex_str(self):
+    def to_hex_str(self) -> str:
         if len(self.uuid_bytes) == 2 or len(self.uuid_bytes) == 4:
             return bytes(reversed(self.uuid_bytes)).hex().upper()
-        else:
-            return ''.join([
+
+        return ''.join(
+            [
                 bytes(reversed(self.uuid_bytes[12:16])).hex(),
                 bytes(reversed(self.uuid_bytes[10:12])).hex(),
                 bytes(reversed(self.uuid_bytes[8:10])).hex(),
                 bytes(reversed(self.uuid_bytes[6:8])).hex(),
-                bytes(reversed(self.uuid_bytes[0:6])).hex()
-            ]).upper()
+                bytes(reversed(self.uuid_bytes[0:6])).hex(),
+            ]
+        ).upper()
 
     def __bytes__(self):
         return self.to_bytes()
 
     def __eq__(self, other):
         if isinstance(other, UUID):
-            return self.to_bytes(force_128 = True) == other.to_bytes(force_128 = True)
-        elif type(other) is str:
+            return self.to_bytes(force_128=True) == other.to_bytes(force_128=True)
+
+        if isinstance(other, str):
             return UUID(other) == self
 
         return False
@@ -213,23 +267,26 @@ class UUID:
 
     def __str__(self):
         if len(self.uuid_bytes) == 2:
-            v = struct.unpack('<H', self.uuid_bytes)[0]
-            result = f'UUID-16:{v:04X}'
+            uuid = struct.unpack('<H', self.uuid_bytes)[0]
+            result = f'UUID-16:{uuid:04X}'
         elif len(self.uuid_bytes) == 4:
-            v = struct.unpack('<I', self.uuid_bytes)[0]
-            result = f'UUID-32:{v:08X}'
+            uuid = struct.unpack('<I', self.uuid_bytes)[0]
+            result = f'UUID-32:{uuid:08X}'
         else:
-            result = '-'.join([
-                bytes(reversed(self.uuid_bytes[12:16])).hex(),
-                bytes(reversed(self.uuid_bytes[10:12])).hex(),
-                bytes(reversed(self.uuid_bytes[8:10])).hex(),
-                bytes(reversed(self.uuid_bytes[6:8])).hex(),
-                bytes(reversed(self.uuid_bytes[0:6])).hex()
-            ]).upper()
+            result = '-'.join(
+                [
+                    bytes(reversed(self.uuid_bytes[12:16])).hex(),
+                    bytes(reversed(self.uuid_bytes[10:12])).hex(),
+                    bytes(reversed(self.uuid_bytes[8:10])).hex(),
+                    bytes(reversed(self.uuid_bytes[6:8])).hex(),
+                    bytes(reversed(self.uuid_bytes[0:6])).hex(),
+                ]
+            ).upper()
+
         if self.name is not None:
             return result + f' ({self.name})'
-        else:
-            return result
+
+        return result
 
     def __repr__(self):
         return str(self)
@@ -238,6 +295,8 @@ class UUID:
 # -----------------------------------------------------------------------------
 # Common UUID constants
 # -----------------------------------------------------------------------------
+# fmt: off
+# pylint: disable=line-too-long
 
 # Protocol Identifiers
 BT_SDP_PROTOCOL_ID                      = UUID.from_16_bits(0x0001, 'SDP')
@@ -343,11 +402,17 @@ BT_HDP_SERVICE                                       = UUID.from_16_bits(0x1400,
 BT_HDP_SOURCE_SERVICE                                = UUID.from_16_bits(0x1401, 'HDP Source')
 BT_HDP_SINK_SERVICE                                  = UUID.from_16_bits(0x1402, 'HDP Sink')
 
+# fmt: on
+# pylint: enable=line-too-long
+
 
 # -----------------------------------------------------------------------------
 # DeviceClass
 # -----------------------------------------------------------------------------
 class DeviceClass:
+    # fmt: off
+    # pylint: disable=line-too-long
+
     # Major Service Classes (flags combined with OR)
     LIMITED_DISCOVERABLE_MODE_SERVICE_CLASS = (1 << 0)
     LE_AUDIO_SERVICE_CLASS                  = (1 << 1)
@@ -515,11 +580,18 @@ class DeviceClass:
         PERIPHERAL_MAJOR_DEVICE_CLASS:  PERIPHERAL_MINOR_DEVICE_CLASS_NAMES
     }
 
+    # fmt: on
+    # pylint: enable=line-too-long
+
     @staticmethod
     def split_class_of_device(class_of_device):
         # Split the bit fields of the composite class of device value into:
         # (service_classes, major_device_class, minor_device_class)
-        return ((class_of_device >> 13 & 0x7FF), (class_of_device >> 8 & 0x1F), (class_of_device >> 2 & 0x3F))
+        return (
+            (class_of_device >> 13 & 0x7FF),
+            (class_of_device >> 8 & 0x1F),
+            (class_of_device >> 2 & 0x3F),
+        )
 
     @staticmethod
     def pack_class_of_device(service_classes, major_device_class, minor_device_class):
@@ -527,7 +599,9 @@ class DeviceClass:
 
     @staticmethod
     def service_class_labels(service_class_flags):
-        return bit_flags_to_strings(service_class_flags, DeviceClass.SERVICE_CLASS_LABELS)
+        return bit_flags_to_strings(
+            service_class_flags, DeviceClass.SERVICE_CLASS_LABELS
+        )
 
     @staticmethod
     def major_device_class_name(device_class):
@@ -544,7 +618,15 @@ class DeviceClass:
 # -----------------------------------------------------------------------------
 # Advertising Data
 # -----------------------------------------------------------------------------
+AdvertisingObject = Union[
+    List[UUID], Tuple[UUID, bytes], bytes, str, int, Tuple[int, int], Tuple[int, bytes]
+]
+
+
 class AdvertisingData:
+    # fmt: off
+    # pylint: disable=line-too-long
+
     # This list is only partial, it still needs to be filled in from the spec
     FLAGS                                          = 0x01
     INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS  = 0x02
@@ -656,7 +738,14 @@ class AdvertisingData:
     BR_EDR_CONTROLLER_FLAG            = 0x08
     BR_EDR_HOST_FLAG                  = 0x10
 
-    def __init__(self, ad_structures = []):
+    ad_structures: List[Tuple[int, bytes]]
+
+    # fmt: on
+    # pylint: enable=line-too-long
+
+    def __init__(self, ad_structures: Optional[List[Tuple[int, bytes]]] = None) -> None:
+        if ad_structures is None:
+            ad_structures = []
         self.ad_structures = ad_structures[:]
 
     @staticmethod
@@ -667,36 +756,36 @@ class AdvertisingData:
 
     @staticmethod
     def flags_to_string(flags, short=False):
-        flag_names = [
-            'LE Limited',
-            'LE General',
-            'No BR/EDR',
-            'BR/EDR C',
-            'BR/EDR H'
-        ] if short else [
-            'LE Limited Discoverable Mode',
-            'LE General Discoverable Mode',
-            'BR/EDR Not Supported',
-            'Simultaneous LE and BR/EDR (Controller)',
-            'Simultaneous LE and BR/EDR (Host)'
-        ]
+        flag_names = (
+            ['LE Limited', 'LE General', 'No BR/EDR', 'BR/EDR C', 'BR/EDR H']
+            if short
+            else [
+                'LE Limited Discoverable Mode',
+                'LE General Discoverable Mode',
+                'BR/EDR Not Supported',
+                'Simultaneous LE and BR/EDR (Controller)',
+                'Simultaneous LE and BR/EDR (Host)',
+            ]
+        )
         return ','.join(bit_flags_to_strings(flags, flag_names))
 
     @staticmethod
-    def uuid_list_to_objects(ad_data, uuid_size):
+    def uuid_list_to_objects(ad_data: bytes, uuid_size: int) -> List[UUID]:
         uuids = []
         offset = 0
         while (uuid_size * (offset + 1)) <= len(ad_data):
-            uuids.append(UUID.from_bytes(ad_data[offset:offset + uuid_size]))
+            uuids.append(UUID.from_bytes(ad_data[offset : offset + uuid_size]))
             offset += uuid_size
         return uuids
 
     @staticmethod
     def uuid_list_to_string(ad_data, uuid_size):
-        return ', '.join([
-            str(uuid)
-            for uuid in AdvertisingData.uuid_list_to_objects(ad_data, uuid_size)
-        ])
+        return ', '.join(
+            [
+                str(uuid)
+                for uuid in AdvertisingData.uuid_list_to_objects(ad_data, uuid_size)
+            ]
+        )
 
     @staticmethod
     def ad_data_to_string(ad_type, ad_data):
@@ -756,40 +845,65 @@ class AdvertisingData:
 
         return f'[{ad_type_str}]: {ad_data_str}'
 
+    # pylint: disable=too-many-return-statements
     @staticmethod
-    def ad_data_to_object(ad_type, ad_data):
-        if ad_type in {
+    def ad_data_to_object(ad_type: int, ad_data: bytes) -> AdvertisingObject:
+        if ad_type in (
             AdvertisingData.COMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS,
-            AdvertisingData.INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS
-        }:
+            AdvertisingData.INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS,
+            AdvertisingData.LIST_OF_16_BIT_SERVICE_SOLICITATION_UUIDS,
+        ):
             return AdvertisingData.uuid_list_to_objects(ad_data, 2)
-        elif ad_type in {
+
+        if ad_type in (
             AdvertisingData.COMPLETE_LIST_OF_32_BIT_SERVICE_CLASS_UUIDS,
-            AdvertisingData.INCOMPLETE_LIST_OF_32_BIT_SERVICE_CLASS_UUIDS
-        }:
+            AdvertisingData.INCOMPLETE_LIST_OF_32_BIT_SERVICE_CLASS_UUIDS,
+            AdvertisingData.LIST_OF_32_BIT_SERVICE_SOLICITATION_UUIDS,
+        ):
             return AdvertisingData.uuid_list_to_objects(ad_data, 4)
-        elif ad_type in {
+
+        if ad_type in (
             AdvertisingData.COMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS,
-            AdvertisingData.INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS
-        }:
+            AdvertisingData.INCOMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS,
+            AdvertisingData.LIST_OF_128_BIT_SERVICE_SOLICITATION_UUIDS,
+        ):
             return AdvertisingData.uuid_list_to_objects(ad_data, 16)
-        elif ad_type == AdvertisingData.SERVICE_DATA_16_BIT_UUID:
+
+        if ad_type == AdvertisingData.SERVICE_DATA_16_BIT_UUID:
             return (UUID.from_bytes(ad_data[:2]), ad_data[2:])
-        elif ad_type == AdvertisingData.SERVICE_DATA_32_BIT_UUID:
+
+        if ad_type == AdvertisingData.SERVICE_DATA_32_BIT_UUID:
             return (UUID.from_bytes(ad_data[:4]), ad_data[4:])
-        elif ad_type == AdvertisingData.SERVICE_DATA_128_BIT_UUID:
+
+        if ad_type == AdvertisingData.SERVICE_DATA_128_BIT_UUID:
             return (UUID.from_bytes(ad_data[:16]), ad_data[16:])
-        elif ad_type in {
+
+        if ad_type in (
             AdvertisingData.SHORTENED_LOCAL_NAME,
-            AdvertisingData.COMPLETE_LOCAL_NAME
-        }:
+            AdvertisingData.COMPLETE_LOCAL_NAME,
+            AdvertisingData.URI,
+        ):
             return ad_data.decode("utf-8")
-        elif ad_type == AdvertisingData.TX_POWER_LEVEL:
-            return ad_data[0]
-        elif ad_type == AdvertisingData.MANUFACTURER_SPECIFIC_DATA:
-            return (struct.unpack_from('<H', ad_data, 0)[0], ad_data[2:])
-        else:
-            return ad_data
+
+        if ad_type in (AdvertisingData.TX_POWER_LEVEL, AdvertisingData.FLAGS):
+            return cast(int, struct.unpack('B', ad_data)[0])
+
+        if ad_type in (
+            AdvertisingData.APPEARANCE,
+            AdvertisingData.ADVERTISING_INTERVAL,
+        ):
+            return cast(int, struct.unpack('<H', ad_data)[0])
+
+        if ad_type == AdvertisingData.CLASS_OF_DEVICE:
+            return cast(int, struct.unpack('<I', bytes([*ad_data, 0]))[0])
+
+        if ad_type == AdvertisingData.PERIPHERAL_CONNECTION_INTERVAL_RANGE:
+            return cast(Tuple[int, int], struct.unpack('<HH', ad_data))
+
+        if ad_type == AdvertisingData.MANUFACTURER_SPECIFIC_DATA:
+            return (cast(int, struct.unpack_from('<H', ad_data, 0)[0]), ad_data[2:])
+
+        return ad_data
 
     def append(self, data):
         offset = 0
@@ -798,30 +912,41 @@ class AdvertisingData:
             offset += 1
             if length > 0:
                 ad_type = data[offset]
-                ad_data = data[offset + 1:offset + length]
+                ad_data = data[offset + 1 : offset + length]
                 self.ad_structures.append((ad_type, ad_data))
             offset += length
 
-    def get(self, type_id, return_all=False, raw=True):
+    def get_all(self, type_id: int, raw: bool = False) -> List[AdvertisingObject]:
         '''
         Get Advertising Data Structure(s) with a given type
 
-        If return_all is True, returns a (possibly empty) list of matches,
-        else returns the first entry, or None if no structure matches.
+        Returns a (possibly empty) list of matches.
         '''
-        def process_ad_data(ad_data):
+
+        def process_ad_data(ad_data: bytes) -> AdvertisingObject:
             return ad_data if raw else self.ad_data_to_object(type_id, ad_data)
 
-        if return_all:
-            return [process_ad_data(ad[1]) for ad in self.ad_structures if ad[0] == type_id]
-        else:
-            return next((process_ad_data(ad[1]) for ad in self.ad_structures if ad[0] == type_id), None)
+        return [process_ad_data(ad[1]) for ad in self.ad_structures if ad[0] == type_id]
+
+    def get(self, type_id: int, raw: bool = False) -> Optional[AdvertisingObject]:
+        '''
+        Get Advertising Data Structure(s) with a given type
+
+        Returns the first entry, or None if no structure matches.
+        '''
+
+        all = self.get_all(type_id, raw=raw)
+        return all[0] if all else None
 
     def __bytes__(self):
-        return b''.join([bytes([len(x[1]) + 1, x[0]]) + x[1] for x in self.ad_structures])
+        return b''.join(
+            [bytes([len(x[1]) + 1, x[0]]) + x[1] for x in self.ad_structures]
+        )
 
     def to_string(self, separator=', '):
-        return separator.join([AdvertisingData.ad_data_to_string(x[0], x[1]) for x in self.ad_structures])
+        return separator.join(
+            [AdvertisingData.ad_data_to_string(x[0], x[1]) for x in self.ad_structures]
+        )
 
     def __str__(self):
         return self.to_string()
@@ -831,13 +956,17 @@ class AdvertisingData:
 # Connection Parameters
 # -----------------------------------------------------------------------------
 class ConnectionParameters:
-    def __init__(self, connection_interval, connection_latency, supervision_timeout):
+    def __init__(self, connection_interval, peripheral_latency, supervision_timeout):
         self.connection_interval = connection_interval
-        self.connection_latency  = connection_latency
+        self.peripheral_latency = peripheral_latency
         self.supervision_timeout = supervision_timeout
 
     def __str__(self):
-        return f'ConnectionParameters(connection_interval={self.connection_interval}, connection_latency={self.connection_latency}, supervision_timeout={self.supervision_timeout}'
+        return (
+            f'ConnectionParameters(connection_interval={self.connection_interval}, '
+            f'peripheral_latency={self.peripheral_latency}, '
+            f'supervision_timeout={self.supervision_timeout}'
+        )
 
 
 # -----------------------------------------------------------------------------

bumble/crypto.py

@@ -24,19 +24,16 @@
 import logging
 import operator
 import platform
+
 if platform.system() != 'Emscripten':
     import secrets
-    from cryptography.hazmat.primitives.ciphers import (
-        Cipher,
-        algorithms,
-        modes
-    )
+    from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
     from cryptography.hazmat.primitives.asymmetric.ec import (
         generate_private_key,
         ECDH,
         EllipticCurvePublicNumbers,
         EllipticCurvePrivateNumbers,
-        SECP256R1
+        SECP256R1,
     )
     from cryptography.hazmat.primitives import cmac
 else:
@@ -66,16 +63,26 @@ class EccKey:
         d = int.from_bytes(d_bytes, byteorder='big', signed=False)
         x = int.from_bytes(x_bytes, byteorder='big', signed=False)
         y = int.from_bytes(y_bytes, byteorder='big', signed=False)
-        private_key = EllipticCurvePrivateNumbers(d, EllipticCurvePublicNumbers(x, y, SECP256R1())).private_key()
+        private_key = EllipticCurvePrivateNumbers(
+            d, EllipticCurvePublicNumbers(x, y, SECP256R1())
+        ).private_key()
         return cls(private_key)
 
     @property
     def x(self):
-        return self.private_key.public_key().public_numbers().x.to_bytes(32, byteorder='big')
+        return (
+            self.private_key.public_key()
+            .public_numbers()
+            .x.to_bytes(32, byteorder='big')
+        )
 
     @property
     def y(self):
-        return self.private_key.public_key().public_numbers().y.to_bytes(32, byteorder='big')
+        return (
+            self.private_key.public_key()
+            .public_numbers()
+            .y.to_bytes(32, byteorder='big')
+        )
 
     def dh(self, public_key_x, public_key_y):
         x = int.from_bytes(public_key_x, byteorder='big', signed=False)
@@ -92,7 +99,7 @@ class EccKey:
 
 # -----------------------------------------------------------------------------
 def xor(x, y):
-    assert(len(x) == len(y))
+    assert len(x) == len(y)
     return bytes(map(operator.xor, x, y))
 
 
@@ -118,7 +125,7 @@ def e(key, data):
 
 
 # -----------------------------------------------------------------------------
-def ah(k, r):
+def ah(k, r):  # pylint: disable=redefined-outer-name
     '''
     See Bluetooth spec Vol 3, Part H - 2.2.2 Random Address Hash function ah
     '''
@@ -129,9 +136,10 @@ def ah(k, r):
 
 
 # -----------------------------------------------------------------------------
-def c1(k, r, preq, pres, iat, rat, ia, ra):
+def c1(k, r, preq, pres, iat, rat, ia, ra):  # pylint: disable=redefined-outer-name
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.3 Confirm value generation function c1 for LE Legacy Pairing
+    See Bluetooth spec, Vol 3, Part H - 2.2.3 Confirm value generation function c1 for
+    LE Legacy Pairing
     '''
 
     p1 = bytes([iat, rat]) + preq + pres
@@ -142,7 +150,8 @@ def c1(k, r, preq, pres, iat, rat, ia, ra):
 # -----------------------------------------------------------------------------
 def s1(k, r1, r2):
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.4 Key generation function s1 for LE Legacy Pairing
+    See Bluetooth spec, Vol 3, Part H - 2.2.4 Key generation function s1 for LE Legacy
+    Pairing
     '''
 
     return e(k, r2[0:8] + r1[0:8])
@@ -163,71 +172,95 @@ def aes_cmac(m, k):
 # -----------------------------------------------------------------------------
 def f4(u, v, x, z):
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.6 LE Secure Connections Confirm Value Generation Function f4
+    See Bluetooth spec, Vol 3, Part H - 2.2.6 LE Secure Connections Confirm Value
+    Generation Function f4
     '''
-    return bytes(reversed(aes_cmac(bytes(reversed(u)) + bytes(reversed(v)) + z, bytes(reversed(x)))))
+    return bytes(
+        reversed(
+            aes_cmac(bytes(reversed(u)) + bytes(reversed(v)) + z, bytes(reversed(x)))
+        )
+    )
 
 
 # -----------------------------------------------------------------------------
 def f5(w, n1, n2, a1, a2):
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.7 LE Secure Connections Key Generation Function f5
+    See Bluetooth spec, Vol 3, Part H - 2.2.7 LE Secure Connections Key Generation
+    Function f5
 
     NOTE: this returns a tuple: (MacKey, LTK) in little-endian byte order
     '''
     salt = bytes.fromhex('6C888391AAF5A53860370BDB5A6083BE')
     t = aes_cmac(bytes(reversed(w)), salt)
-    key_id = bytes([0x62, 0x74, 0x6c, 0x65])
+    key_id = bytes([0x62, 0x74, 0x6C, 0x65])
     return (
-        bytes(reversed(aes_cmac(
-            bytes([0]) +
-            key_id +
-            bytes(reversed(n1)) +
-            bytes(reversed(n2)) +
-            bytes(reversed(a1)) +
-            bytes(reversed(a2)) +
-            bytes([1, 0]),
-            t
-        ))),
-        bytes(reversed(aes_cmac(
-            bytes([1]) +
-            key_id +
-            bytes(reversed(n1)) +
-            bytes(reversed(n2)) +
-            bytes(reversed(a1)) +
-            bytes(reversed(a2)) +
-            bytes([1, 0]),
-            t
-        )))
+        bytes(
+            reversed(
+                aes_cmac(
+                    bytes([0])
+                    + key_id
+                    + bytes(reversed(n1))
+                    + bytes(reversed(n2))
+                    + bytes(reversed(a1))
+                    + bytes(reversed(a2))
+                    + bytes([1, 0]),
+                    t,
+                )
+            )
+        ),
+        bytes(
+            reversed(
+                aes_cmac(
+                    bytes([1])
+                    + key_id
+                    + bytes(reversed(n1))
+                    + bytes(reversed(n2))
+                    + bytes(reversed(a1))
+                    + bytes(reversed(a2))
+                    + bytes([1, 0]),
+                    t,
+                )
+            )
+        ),
     )
 
 
 # -----------------------------------------------------------------------------
-def f6(w, n1, n2, r, io_cap, a1, a2):
+def f6(w, n1, n2, r, io_cap, a1, a2):  # pylint: disable=redefined-outer-name
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.8 LE Secure Connections Check Value Generation Function f6
+    See Bluetooth spec, Vol 3, Part H - 2.2.8 LE Secure Connections Check Value
+    Generation Function f6
     '''
-    return bytes(reversed(aes_cmac(
-        bytes(reversed(n1)) +
-        bytes(reversed(n2)) +
-        bytes(reversed(r)) +
-        bytes(reversed(io_cap)) +
-        bytes(reversed(a1)) +
-        bytes(reversed(a2)),
-        bytes(reversed(w))
-    )))
+    return bytes(
+        reversed(
+            aes_cmac(
+                bytes(reversed(n1))
+                + bytes(reversed(n2))
+                + bytes(reversed(r))
+                + bytes(reversed(io_cap))
+                + bytes(reversed(a1))
+                + bytes(reversed(a2)),
+                bytes(reversed(w)),
+            )
+        )
+    )
 
 
 # -----------------------------------------------------------------------------
 def g2(u, v, x, y):
     '''
-    See Bluetooth spec, Vol 3, Part H - 2.2.9 LE Secure Connections Numeric Comparison Value Generation Function g2
+    See Bluetooth spec, Vol 3, Part H - 2.2.9 LE Secure Connections Numeric Comparison
+    Value Generation Function g2
     '''
     return int.from_bytes(
-        aes_cmac(bytes(reversed(u)) + bytes(reversed(v)) + bytes(reversed(y)), bytes(reversed(x)))[-4:],
-        byteorder='big'
+        aes_cmac(
+            bytes(reversed(u)) + bytes(reversed(v)) + bytes(reversed(y)),
+            bytes(reversed(x)),
+        )[-4:],
+        byteorder='big',
     )
 
+
 # -----------------------------------------------------------------------------
 def h6(w, key_id):
     '''
@@ -235,6 +268,7 @@ def h6(w, key_id):
     '''
     return aes_cmac(key_id, w)
 
+
 # -----------------------------------------------------------------------------
 def h7(salt, w):
     '''

bumble/decoder.py

@@ -0,0 +1,416 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Constants
+# -----------------------------------------------------------------------------
+# fmt: off
+
+WL = [-60, -30, 58, 172, 334, 538, 1198, 3042]
+RL42 = [0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 0]
+ILB = [
+    2048,
+    2093,
+    2139,
+    2186,
+    2233,
+    2282,
+    2332,
+    2383,
+    2435,
+    2489,
+    2543,
+    2599,
+    2656,
+    2714,
+    2774,
+    2834,
+    2896,
+    2960,
+    3025,
+    3091,
+    3158,
+    3228,
+    3298,
+    3371,
+    3444,
+    3520,
+    3597,
+    3676,
+    3756,
+    3838,
+    3922,
+    4008,
+]
+WH = [0, -214, 798]
+RH2 = [2, 1, 2, 1]
+# Values in QM2/QM4/QM6 left shift three bits than original g722 specification.
+QM2 = [-7408, -1616, 7408, 1616]
+QM4 = [
+    0,
+    -20456,
+    -12896,
+    -8968,
+    -6288,
+    -4240,
+    -2584,
+    -1200,
+    20456,
+    12896,
+    8968,
+    6288,
+    4240,
+    2584,
+    1200,
+    0,
+]
+QM6 = [
+    -136,
+    -136,
+    -136,
+    -136,
+    -24808,
+    -21904,
+    -19008,
+    -16704,
+    -14984,
+    -13512,
+    -12280,
+    -11192,
+    -10232,
+    -9360,
+    -8576,
+    -7856,
+    -7192,
+    -6576,
+    -6000,
+    -5456,
+    -4944,
+    -4464,
+    -4008,
+    -3576,
+    -3168,
+    -2776,
+    -2400,
+    -2032,
+    -1688,
+    -1360,
+    -1040,
+    -728,
+    24808,
+    21904,
+    19008,
+    16704,
+    14984,
+    13512,
+    12280,
+    11192,
+    10232,
+    9360,
+    8576,
+    7856,
+    7192,
+    6576,
+    6000,
+    5456,
+    4944,
+    4464,
+    4008,
+    3576,
+    3168,
+    2776,
+    2400,
+    2032,
+    1688,
+    1360,
+    1040,
+    728,
+    432,
+    136,
+    -432,
+    -136,
+]
+QMF_COEFFS = [3, -11, 12, 32, -210, 951, 3876, -805, 362, -156, 53, -11]
+
+# fmt: on
+
+
+# -----------------------------------------------------------------------------
+# Classes
+# -----------------------------------------------------------------------------
+class G722Decoder(object):
+    """G.722 decoder with bitrate 64kbit/s.
+
+    For the Blocks in the sub-band decoders, please refer to the G.722
+    specification for the required information. G722 specification:
+    https://www.itu.int/rec/T-REC-G.722-201209-I
+    """
+
+    def __init__(self):
+        self._x = [0] * 24
+        self._band = [Band(), Band()]
+        # The initial value in BLOCK 3L
+        self._band[0].det = 32
+        # The initial value in BLOCK 3H
+        self._band[1].det = 8
+
+    def decode_frame(self, encoded_data) -> bytearray:
+        result_array = bytearray(len(encoded_data) * 4)
+        self.g722_decode(result_array, encoded_data)
+        return result_array
+
+    def g722_decode(self, result_array, encoded_data) -> int:
+        """Decode the data frame using g722 decoder."""
+        result_length = 0
+
+        for code in encoded_data:
+            higher_bits = (code >> 6) & 0x03
+            lower_bits = code & 0x3F
+
+            rlow = self.lower_sub_band_decoder(lower_bits)
+            rhigh = self.higher_sub_band_decoder(higher_bits)
+
+            # Apply the receive QMF
+            self._x[:22] = self._x[2:]
+            self._x[22] = rlow + rhigh
+            self._x[23] = rlow - rhigh
+
+            xout2 = sum(self._x[2 * i] * QMF_COEFFS[i] for i in range(12))
+            xout1 = sum(self._x[2 * i + 1] * QMF_COEFFS[11 - i] for i in range(12))
+
+            result_length = self.update_decoded_result(
+                xout1, result_length, result_array
+            )
+            result_length = self.update_decoded_result(
+                xout2, result_length, result_array
+            )
+
+        return result_length
+
+    def update_decoded_result(self, xout, byte_length, byte_array) -> int:
+        result = (int)(xout >> 11)
+        bytes_result = result.to_bytes(2, 'little', signed=True)
+        byte_array[byte_length] = bytes_result[0]
+        byte_array[byte_length + 1] = bytes_result[1]
+        return byte_length + 2
+
+    def lower_sub_band_decoder(self, lower_bits) -> int:
+        """Lower sub-band decoder for last six bits."""
+
+        # Block 5L
+        # INVQBL
+        wd1 = lower_bits
+        wd2 = QM6[wd1]
+        wd1 >>= 2
+        wd2 = (self._band[0].det * wd2) >> 15
+        # RECONS
+        rlow = self._band[0].s + wd2
+
+        # Block 6L
+        # LIMIT
+        if rlow > 16383:
+            rlow = 16383
+        elif rlow < -16384:
+            rlow = -16384
+
+        # Block 2L
+        # INVQAL
+        wd2 = QM4[wd1]
+        dlowt = (self._band[0].det * wd2) >> 15
+
+        # Block 3L
+        # LOGSCL
+        wd2 = RL42[wd1]
+        wd1 = (self._band[0].nb * 127) >> 7
+        wd1 += WL[wd2]
+
+        if wd1 < 0:
+            wd1 = 0
+        elif wd1 > 18432:
+            wd1 = 18432
+
+        self._band[0].nb = wd1
+
+        # SCALEL
+        wd1 = (self._band[0].nb >> 6) & 31
+        wd2 = 8 - (self._band[0].nb >> 11)
+
+        if wd2 < 0:
+            wd3 = ILB[wd1] << -wd2
+        else:
+            wd3 = ILB[wd1] >> wd2
+
+        self._band[0].det = wd3 << 2
+
+        # Block 4L
+        self._band[0].block4(dlowt)
+
+        return rlow
+
+    def higher_sub_band_decoder(self, higher_bits) -> int:
+        """Higher sub-band decoder for first two bits."""
+
+        # Block 2H
+        # INVQAH
+        wd2 = QM2[higher_bits]
+        dhigh = (self._band[1].det * wd2) >> 15
+
+        # Block 5H
+        # RECONS
+        rhigh = dhigh + self._band[1].s
+
+        # Block 6H
+        # LIMIT
+        if rhigh > 16383:
+            rhigh = 16383
+        elif rhigh < -16384:
+            rhigh = -16384
+
+        # Block 3H
+        # LOGSCH
+        wd2 = RH2[higher_bits]
+        wd1 = (self._band[1].nb * 127) >> 7
+        wd1 += WH[wd2]
+
+        if wd1 < 0:
+            wd1 = 0
+        elif wd1 > 22528:
+            wd1 = 22528
+        self._band[1].nb = wd1
+
+        # SCALEH
+        wd1 = (self._band[1].nb >> 6) & 31
+        wd2 = 10 - (self._band[1].nb >> 11)
+
+        if wd2 < 0:
+            wd3 = ILB[wd1] << -wd2
+        else:
+            wd3 = ILB[wd1] >> wd2
+        self._band[1].det = wd3 << 2
+
+        # Block 4H
+        self._band[1].block4(dhigh)
+
+        return rhigh
+
+
+# -----------------------------------------------------------------------------
+class Band(object):
+    """Structure for G722 decode proccessing."""
+
+    s: int = 0
+    nb: int = 0
+    det: int = 0
+
+    def __init__(self):
+        self._sp = 0
+        self._sz = 0
+        self._r = [0] * 3
+        self._a = [0] * 3
+        self._ap = [0] * 3
+        self._p = [0] * 3
+        self._d = [0] * 7
+        self._b = [0] * 7
+        self._bp = [0] * 7
+        self._sg = [0] * 7
+
+    def saturate(self, amp: int) -> int:
+        if amp > 32767:
+            return 32767
+        elif amp < -32768:
+            return -32768
+        else:
+            return amp
+
+    def block4(self, d: int) -> None:
+        """Block4 for both lower and higher sub-band decoder."""
+        wd1 = 0
+        wd2 = 0
+        wd3 = 0
+
+        # RECONS
+        self._d[0] = d
+        self._r[0] = self.saturate(self.s + d)
+
+        # PARREC
+        self._p[0] = self.saturate(self._sz + d)
+
+        # UPPOL2
+        for i in range(3):
+            self._sg[i] = (self._p[i]) >> 15
+        wd1 = self.saturate((self._a[1]) << 2)
+        wd2 = -wd1 if self._sg[0] == self._sg[1] else wd1
+
+        if wd2 > 32767:
+            wd2 = 32767
+
+        wd3 = 128 if self._sg[0] == self._sg[2] else -128
+        wd3 += wd2 >> 7
+        wd3 += (self._a[2] * 32512) >> 15
+
+        if wd3 > 12288:
+            wd3 = 12288
+        elif wd3 < -12288:
+            wd3 = -12288
+        self._ap[2] = wd3
+
+        # UPPOL1
+        self._sg[0] = (self._p[0]) >> 15
+        self._sg[1] = (self._p[1]) >> 15
+        wd1 = 192 if self._sg[0] == self._sg[1] else -192
+        wd2 = (self._a[1] * 32640) >> 15
+
+        self._ap[1] = self.saturate(wd1 + wd2)
+        wd3 = self.saturate(15360 - self._ap[2])
+
+        if self._ap[1] > wd3:
+            self._ap[1] = wd3
+        elif self._ap[1] < -wd3:
+            self._ap[1] = -wd3
+
+        # UPZERO
+        wd1 = 0 if d == 0 else 128
+        self._sg[0] = d >> 15
+        for i in range(1, 7):
+            self._sg[i] = (self._d[i]) >> 15
+            wd2 = wd1 if self._sg[i] == self._sg[0] else -wd1
+            wd3 = (self._b[i] * 32640) >> 15
+            self._bp[i] = self.saturate(wd2 + wd3)
+
+        # DELAYA
+        for i in range(6, 0, -1):
+            self._d[i] = self._d[i - 1]
+            self._b[i] = self._bp[i]
+
+        for i in range(2, 0, -1):
+            self._r[i] = self._r[i - 1]
+            self._p[i] = self._p[i - 1]
+            self._a[i] = self._ap[i]
+
+        # FILTEP
+        self._sp = 0
+        for i in range(1, 3):
+            wd1 = self.saturate(self._r[i] + self._r[i])
+            self._sp += (self._a[i] * wd1) >> 15
+        self._sp = self.saturate(self._sp)
+
+        # FILTEZ
+        self._sz = 0
+        for i in range(6, 0, -1):
+            wd1 = self.saturate(self._d[i] + self._d[i])
+            self._sz += (self._b[i] * wd1) >> 15
+        self._sz = self.saturate(self._sz)
+
+        # PREDIC
+        self.s = self.saturate(self._sp + self._sz)

bumble/gap.py

@@ -23,7 +23,7 @@ from .gatt import (
     Characteristic,
     GATT_GENERIC_ACCESS_SERVICE,
     GATT_DEVICE_NAME_CHARACTERISTIC,
-    GATT_APPEARANCE_CHARACTERISTIC
+    GATT_APPEARANCE_CHARACTERISTIC,
 )
 
 # -----------------------------------------------------------------------------
@@ -38,22 +38,22 @@ logger = logging.getLogger(__name__)
 
 # -----------------------------------------------------------------------------
 class GenericAccessService(Service):
-    def __init__(self, device_name, appearance = (0, 0)):
+    def __init__(self, device_name, appearance=(0, 0)):
         device_name_characteristic = Characteristic(
             GATT_DEVICE_NAME_CHARACTERISTIC,
-            Characteristic.READ,
+            Characteristic.Properties.READ,
             Characteristic.READABLE,
-            device_name.encode('utf-8')[:248]
+            device_name.encode('utf-8')[:248],
         )
 
         appearance_characteristic = Characteristic(
             GATT_APPEARANCE_CHARACTERISTIC,
-            Characteristic.READ,
+            Characteristic.Properties.READ,
             Characteristic.READABLE,
-            struct.pack('<H', (appearance[0] << 6) | appearance[1])
+            struct.pack('<H', (appearance[0] << 6) | appearance[1]),
         )
 
-        super().__init__(GATT_GENERIC_ACCESS_SERVICE, [
-            device_name_characteristic,
-            appearance_characteristic
-        ])
+        super().__init__(
+            GATT_GENERIC_ACCESS_SERVICE,
+            [device_name_characteristic, appearance_characteristic],
+        )

bumble/gatt.py

@@ -22,14 +22,18 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
 import asyncio
-import types
+import enum
+import functools
 import logging
-from colors import color
+import struct
+from typing import Optional, Sequence, List
+
+from .colors import color
+from .core import UUID, get_dict_key_by_value
+from .att import Attribute
 
-from .core import *
-from .hci import *
-from .att import *
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -39,6 +43,9 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+# pylint: disable=line-too-long
+
 GATT_REQUEST_TIMEOUT = 30  # seconds
 
 GATT_MAX_ATTRIBUTE_VALUE_SIZE = 512
@@ -149,6 +156,14 @@ GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC = UUID.from_16_bits(0x2A39, 'Heart
 # Battery Service
 GATT_BATTERY_LEVEL_CHARACTERISTIC = UUID.from_16_bits(0x2A19, 'Battery Level')
 
+# ASHA Service
+GATT_ASHA_SERVICE                             = UUID.from_16_bits(0xFDF0, 'Audio Streaming for Hearing Aid')
+GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC = UUID('6333651e-c481-4a3e-9169-7c902aad37bb', 'ReadOnlyProperties')
+GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC  = UUID('f0d4de7e-4a88-476c-9d9f-1937b0996cc0', 'AudioControlPoint')
+GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC         = UUID('38663f1a-e711-4cac-b641-326b56404837', 'AudioStatus')
+GATT_ASHA_VOLUME_CHARACTERISTIC               = UUID('00e4ca9e-ab14-41e4-8823-f9e70c7e91df', 'Volume')
+GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC           = UUID('2d410339-82b6-42aa-b34e-e2e01df8cc1a', 'LE_PSM_OUT')
+
 # Misc
 GATT_DEVICE_NAME_CHARACTERISTIC                                = UUID.from_16_bits(0x2A00, 'Device Name')
 GATT_APPEARANCE_CHARACTERISTIC                                 = UUID.from_16_bits(0x2A01, 'Appearance')
@@ -163,11 +178,15 @@ GATT_CURRENT_TIME_CHARACTERISTIC                               = UUID.from_16_bi
 GATT_BOOT_KEYBOARD_OUTPUT_REPORT_CHARACTERISTIC                = UUID.from_16_bits(0x2A32, 'Boot Keyboard Output Report')
 GATT_CENTRAL_ADDRESS_RESOLUTION__CHARACTERISTIC                = UUID.from_16_bits(0x2AA6, 'Central Address Resolution')
 
+# fmt: on
+# pylint: enable=line-too-long
+
 
 # -----------------------------------------------------------------------------
 # Utils
 # -----------------------------------------------------------------------------
 
+
 def show_services(services):
     for service in services:
         print(color(str(service), 'cyan'))
@@ -185,23 +204,40 @@ class Service(Attribute):
     See Vol 3, Part G - 3.1 SERVICE DEFINITION
     '''
 
-    def __init__(self, uuid, characteristics, primary=True):
+    uuid: UUID
+
+    def __init__(self, uuid, characteristics: list[Characteristic], primary=True):
         # Convert the uuid to a UUID object if it isn't already
-        if type(uuid) is str:
+        if isinstance(uuid, str):
             uuid = UUID(uuid)
 
         super().__init__(
-            GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE if primary else GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
+            GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE
+            if primary
+            else GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
             Attribute.READABLE,
-            uuid.to_pdu_bytes()
+            uuid.to_pdu_bytes(),
         )
-        self.uuid              = uuid
-        self.included_services = []
-        self.characteristics   = characteristics[:]
-        self.primary           = primary
+        self.uuid = uuid
+        # self.included_services = []
+        self.characteristics = characteristics[:]
+        self.primary = primary
+
+    def get_advertising_data(self) -> Optional[bytes]:
+        """
+        Get Service specific advertising data
+        Defined by each Service, default value is empty
+        :return Service data for advertising
+        """
+        return None
 
     def __str__(self):
-        return f'Service(handle=0x{self.handle:04X}, end=0x{self.end_group_handle:04X}, uuid={self.uuid}){"" if self.primary else "*"}'
+        return (
+            f'Service(handle=0x{self.handle:04X}, '
+            f'end=0x{self.end_group_handle:04X}, '
+            f'uuid={self.uuid})'
+            f'{"" if self.primary else "*"}'
+        )
 
 
 # -----------------------------------------------------------------------------
@@ -210,6 +246,7 @@ class TemplateService(Service):
     Convenience abstract class that can be used by profile-specific subclasses that want
     to expose their UUID as a class property
     '''
+
     UUID = None
 
     def __init__(self, characteristics, primary=True):
@@ -222,51 +259,115 @@ class Characteristic(Attribute):
     See Vol 3, Part G - 3.3 CHARACTERISTIC DEFINITION
     '''
 
-    # Property flags
-    BROADCAST                   = 0x01
-    READ                        = 0x02
-    WRITE_WITHOUT_RESPONSE      = 0x04
-    WRITE                       = 0x08
-    NOTIFY                      = 0x10
-    INDICATE                    = 0X20
-    AUTHENTICATED_SIGNED_WRITES = 0X40
-    EXTENDED_PROPERTIES         = 0X80
+    uuid: UUID
+    properties: Characteristic.Properties
 
-    PROPERTY_NAMES = {
-        BROADCAST:                   'BROADCAST',
-        READ:                        'READ',
-        WRITE_WITHOUT_RESPONSE:      'WRITE_WITHOUT_RESPONSE',
-        WRITE:                       'WRITE',
-        NOTIFY:                      'NOTIFY',
-        INDICATE:                    'INDICATE',
-        AUTHENTICATED_SIGNED_WRITES: 'AUTHENTICATED_SIGNED_WRITES',
-        EXTENDED_PROPERTIES:         'EXTENDED_PROPERTIES'
-    }
+    class Properties(enum.IntFlag):
+        """Property flags"""
 
-    @staticmethod
-    def property_name(property):
-        return Characteristic.PROPERTY_NAMES.get(property, '')
+        BROADCAST = 0x01
+        READ = 0x02
+        WRITE_WITHOUT_RESPONSE = 0x04
+        WRITE = 0x08
+        NOTIFY = 0x10
+        INDICATE = 0x20
+        AUTHENTICATED_SIGNED_WRITES = 0x40
+        EXTENDED_PROPERTIES = 0x80
 
-    @staticmethod
-    def properties_as_string(properties):
-        return ','.join([
-            Characteristic.property_name(p) for p in Characteristic.PROPERTY_NAMES.keys()
-            if properties & p
-        ])
+        @staticmethod
+        def from_string(properties_str: str) -> Characteristic.Properties:
+            property_names: List[str] = []
+            for property in Characteristic.Properties:
+                if property.name is None:
+                    raise TypeError()
+                property_names.append(property.name)
 
-    def __init__(self, uuid, properties, permissions, value = b'', descriptors = []):
+            def string_to_property(property_string) -> Characteristic.Properties:
+                for property in zip(Characteristic.Properties, property_names):
+                    if property_string == property[1]:
+                        return property[0]
+                raise TypeError(f"Unable to convert {property_string} to Property")
+
+            try:
+                return functools.reduce(
+                    lambda x, y: x | string_to_property(y),
+                    properties_str.split(","),
+                    Characteristic.Properties(0),
+                )
+            except TypeError:
+                raise TypeError(
+                    f"Characteristic.Properties::from_string() error:\nExpected a string containing any of the keys, separated by commas: {','.join(property_names)}\nGot: {properties_str}"
+                )
+
+    # For backwards compatibility these are defined here
+    # For new code, please use Characteristic.Properties.X
+    BROADCAST = Properties.BROADCAST
+    READ = Properties.READ
+    WRITE_WITHOUT_RESPONSE = Properties.WRITE_WITHOUT_RESPONSE
+    WRITE = Properties.WRITE
+    NOTIFY = Properties.NOTIFY
+    INDICATE = Properties.INDICATE
+    AUTHENTICATED_SIGNED_WRITES = Properties.AUTHENTICATED_SIGNED_WRITES
+    EXTENDED_PROPERTIES = Properties.EXTENDED_PROPERTIES
+
+    def __init__(
+        self,
+        uuid,
+        properties: Characteristic.Properties,
+        permissions,
+        value=b'',
+        descriptors: Sequence[Descriptor] = (),
+    ):
         super().__init__(uuid, permissions, value)
-        self.uuid        = self.type
-        self.properties  = properties
+        self.uuid = self.type
+        self.properties = properties
         self.descriptors = descriptors
 
     def get_descriptor(self, descriptor_type):
         for descriptor in self.descriptors:
-            if descriptor.uuid == descriptor_type:
+            if descriptor.type == descriptor_type:
                 return descriptor
 
+        return None
+
+    def has_properties(self, properties: Characteristic.Properties) -> bool:
+        return self.properties & properties == properties
+
     def __str__(self):
-        return f'Characteristic(handle=0x{self.handle:04X}, end=0x{self.end_group_handle:04X}, uuid={self.uuid}, properties={Characteristic.properties_as_string(self.properties)})'
+        return (
+            f'Characteristic(handle=0x{self.handle:04X}, '
+            f'end=0x{self.end_group_handle:04X}, '
+            f'uuid={self.uuid}, '
+            f'{self.properties!s})'
+        )
+
+
+# -----------------------------------------------------------------------------
+class CharacteristicDeclaration(Attribute):
+    '''
+    See Vol 3, Part G - 3.3.1 CHARACTERISTIC DECLARATION
+    '''
+
+    characteristic: Characteristic
+
+    def __init__(self, characteristic, value_handle):
+        declaration_bytes = (
+            struct.pack('<BH', characteristic.properties, value_handle)
+            + characteristic.uuid.to_pdu_bytes()
+        )
+        super().__init__(
+            GATT_CHARACTERISTIC_ATTRIBUTE_TYPE, Attribute.READABLE, declaration_bytes
+        )
+        self.value_handle = value_handle
+        self.characteristic = characteristic
+
+    def __str__(self):
+        return (
+            f'CharacteristicDeclaration(handle=0x{self.handle:04X}, '
+            f'value_handle=0x{self.value_handle:04X}, '
+            f'uuid={self.characteristic.uuid}, '
+            f'{self.characteristic.properties!s})'
+        )
 
 
 # -----------------------------------------------------------------------------
@@ -275,6 +376,7 @@ class CharacteristicValue:
     Characteristic value where reading and/or writing is delegated to functions
     passed as arguments to the constructor.
     '''
+
     def __init__(self, read=None, write=None):
         self._read = read
         self._write = write
@@ -301,27 +403,38 @@ class CharacteristicAdapter:
     If the characteristic has a `subscribe` method, it is wrapped with one where
     the values are decoded before being passed to the subscriber.
     '''
+
     def __init__(self, characteristic):
         self.wrapped_characteristic = characteristic
+        self.subscribers = {}  # Map from subscriber to proxy subscriber
 
-        if (
-            asyncio.iscoroutinefunction(characteristic.read_value) and
-            asyncio.iscoroutinefunction(characteristic.write_value)
-        ):
-            self.read_value  = self.read_decoded_value
+        if asyncio.iscoroutinefunction(
+            characteristic.read_value
+        ) and asyncio.iscoroutinefunction(characteristic.write_value):
+            self.read_value = self.read_decoded_value
             self.write_value = self.write_decoded_value
         else:
-            self.read_value  = self.read_encoded_value
+            self.read_value = self.read_encoded_value
             self.write_value = self.write_encoded_value
 
         if hasattr(self.wrapped_characteristic, 'subscribe'):
             self.subscribe = self.wrapped_subscribe
 
+        if hasattr(self.wrapped_characteristic, 'unsubscribe'):
+            self.unsubscribe = self.wrapped_unsubscribe
+
     def __getattr__(self, name):
         return getattr(self.wrapped_characteristic, name)
 
     def __setattr__(self, name, value):
-        if name in {'wrapped_characteristic', 'read_value', 'write_value', 'subscribe'}:
+        if name in (
+            'wrapped_characteristic',
+            'subscribers',
+            'read_value',
+            'write_value',
+            'subscribe',
+            'unsubscribe',
+        ):
             super().__setattr__(name, value)
         else:
             setattr(self.wrapped_characteristic, name, value)
@@ -330,13 +443,17 @@ class CharacteristicAdapter:
         return self.encode_value(self.wrapped_characteristic.read_value(connection))
 
     def write_encoded_value(self, connection, value):
-        return self.wrapped_characteristic.write_value(connection, self.decode_value(value))
+        return self.wrapped_characteristic.write_value(
+            connection, self.decode_value(value)
+        )
 
     async def read_decoded_value(self):
         return self.decode_value(await self.wrapped_characteristic.read_value())
 
-    async def write_decoded_value(self, value):
-        return await self.wrapped_characteristic.write_value(self.encode_value(value))
+    async def write_decoded_value(self, value, with_response=False):
+        return await self.wrapped_characteristic.write_value(
+            self.encode_value(value), with_response
+        )
 
     def encode_value(self, value):
         return value
@@ -345,9 +462,27 @@ class CharacteristicAdapter:
         return value
 
     def wrapped_subscribe(self, subscriber=None):
-        return self.wrapped_characteristic.subscribe(
-            None if subscriber is None else lambda value: subscriber(self.decode_value(value))
-        )
+        if subscriber is not None:
+            if subscriber in self.subscribers:
+                # We already have a proxy subscriber
+                subscriber = self.subscribers[subscriber]
+            else:
+                # Create and register a proxy that will decode the value
+                original_subscriber = subscriber
+
+                def on_change(value):
+                    original_subscriber(self.decode_value(value))
+
+                self.subscribers[subscriber] = on_change
+                subscriber = on_change
+
+        return self.wrapped_characteristic.subscribe(subscriber)
+
+    def wrapped_unsubscribe(self, subscriber=None):
+        if subscriber in self.subscribers:
+            subscriber = self.subscribers.pop(subscriber)
+
+        return self.wrapped_characteristic.unsubscribe(subscriber)
 
     def __str__(self):
         wrapped = str(self.wrapped_characteristic)
@@ -359,6 +494,7 @@ class DelegatedCharacteristicAdapter(CharacteristicAdapter):
     '''
     Adapter that converts bytes values using an encode and a decode function.
     '''
+
     def __init__(self, characteristic, encode=None, decode=None):
         super().__init__(characteristic)
         self.encode = encode
@@ -381,9 +517,10 @@ class PackedCharacteristicAdapter(CharacteristicAdapter):
     they return/accept a tuple with the same number of elements as is required for
     the format.
     '''
-    def __init__(self, characteristic, format):
+
+    def __init__(self, characteristic, pack_format):
         super().__init__(characteristic)
-        self.struct = struct.Struct(format)
+        self.struct = struct.Struct(pack_format)
 
     def pack(self, *values):
         return self.struct.pack(*values)
@@ -392,7 +529,7 @@ class PackedCharacteristicAdapter(CharacteristicAdapter):
         return self.struct.unpack(buffer)
 
     def encode_value(self, value):
-        return self.pack(*value if type(value) is tuple else (value,))
+        return self.pack(*value if isinstance(value, tuple) else (value,))
 
     def decode_value(self, value):
         unpacked = self.unpack(value)
@@ -405,13 +542,15 @@ class MappedCharacteristicAdapter(PackedCharacteristicAdapter):
     Adapter that packs/unpacks characteristic values according to a standard
     Python `struct` format.
     The adapted `read_value` and `write_value` methods return/accept aa dictionary which
-    is packed/unpacked according to format, with the arguments extracted from the dictionary
-    by key, in the same order as they occur in the `keys` parameter.
+    is packed/unpacked according to format, with the arguments extracted from the
+    dictionary by key, in the same order as they occur in the `keys` parameter.
     '''
-    def __init__(self, characteristic, format, keys):
-        super().__init__(characteristic, format)
+
+    def __init__(self, characteristic, pack_format, keys):
+        super().__init__(characteristic, pack_format)
         self.keys = keys
 
+    # pylint: disable=arguments-differ
     def pack(self, values):
         return super().pack(*(values[key] for key in self.keys))
 
@@ -424,6 +563,7 @@ class UTF8CharacteristicAdapter(CharacteristicAdapter):
     '''
     Adapter that converts strings to/from bytes using UTF-8 encoding
     '''
+
     def encode_value(self, value):
         return value.encode('utf-8')
 
@@ -437,8 +577,20 @@ class Descriptor(Attribute):
     See Vol 3, Part G - 3.3.3 Characteristic Descriptor Declarations
     '''
 
-    def __init__(self, descriptor_type, permissions, value = b''):
-        super().__init__(descriptor_type, permissions, value)
-
     def __str__(self):
-        return f'Descriptor(handle=0x{self.handle:04X}, type={self.type}, value={self.read_value(None).hex()})'
+        return (
+            f'Descriptor(handle=0x{self.handle:04X}, '
+            f'type={self.type}, '
+            f'value={self.read_value(None).hex()})'
+        )
+
+
+class ClientCharacteristicConfigurationBits(enum.IntFlag):
+    '''
+    See Vol 3, Part G - 3.3.3.3 - Table 3.11 Client Characteristic Configuration bit
+    field definition
+    '''
+
+    DEFAULT = 0x0000
+    NOTIFICATION = 0x0001
+    INDICATION = 0x0002

bumble/gatt_client.py

@@ -23,21 +23,48 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
 import asyncio
 import logging
 import struct
-from colors import color
+from datetime import datetime
+from typing import List, Optional, Dict, Tuple, Callable, Union, Any
 
-from .core import ProtocolError, TimeoutError
-from .hci import *
-from .att import *
+from pyee import EventEmitter
+
+from .colors import color
+from .hci import HCI_Constant
+from .att import (
+    ATT_ATTRIBUTE_NOT_FOUND_ERROR,
+    ATT_ATTRIBUTE_NOT_LONG_ERROR,
+    ATT_CID,
+    ATT_DEFAULT_MTU,
+    ATT_ERROR_RESPONSE,
+    ATT_INVALID_OFFSET_ERROR,
+    ATT_PDU,
+    ATT_RESPONSES,
+    ATT_Exchange_MTU_Request,
+    ATT_Find_By_Type_Value_Request,
+    ATT_Find_Information_Request,
+    ATT_Handle_Value_Confirmation,
+    ATT_Read_Blob_Request,
+    ATT_Read_By_Group_Type_Request,
+    ATT_Read_By_Type_Request,
+    ATT_Read_Request,
+    ATT_Write_Command,
+    ATT_Write_Request,
+    ATT_Error,
+)
+from . import core
+from .core import UUID, InvalidStateError, ProtocolError
 from .gatt import (
-    GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
-    GATT_REQUEST_TIMEOUT,
-    GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
-    GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
     GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
-    Characteristic
+    GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
+    GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
+    GATT_REQUEST_TIMEOUT,
+    GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
+    Characteristic,
+    ClientCharacteristicConfigurationBits,
 )
 
 # -----------------------------------------------------------------------------
@@ -50,38 +77,58 @@ logger = logging.getLogger(__name__)
 # Proxies
 # -----------------------------------------------------------------------------
 class AttributeProxy(EventEmitter):
+    client: Client
+
     def __init__(self, client, handle, end_group_handle, attribute_type):
         EventEmitter.__init__(self)
-        self.client           = client
-        self.handle           = handle
+        self.client = client
+        self.handle = handle
         self.end_group_handle = end_group_handle
-        self.type             = attribute_type
+        self.type = attribute_type
 
     async def read_value(self, no_long_read=False):
-        return await self.client.read_value(self.handle, no_long_read)
+        return self.decode_value(
+            await self.client.read_value(self.handle, no_long_read)
+        )
 
     async def write_value(self, value, with_response=False):
-        return await self.client.write_value(self.handle, value, with_response)
+        return await self.client.write_value(
+            self.handle, self.encode_value(value), with_response
+        )
+
+    def encode_value(self, value):
+        return value
+
+    def decode_value(self, value_bytes):
+        return value_bytes
 
     def __str__(self):
-        return f'Attribute(handle=0x{self.handle:04X}, type={self.uuid})'
+        return f'Attribute(handle=0x{self.handle:04X}, type={self.type})'
 
 
 class ServiceProxy(AttributeProxy):
+    uuid: UUID
+    characteristics: List[CharacteristicProxy]
+
     @staticmethod
-    def from_client(cls, client, service_uuid):
-        # The service and its characteristics are considered to have already been discovered
+    def from_client(service_class, client, service_uuid):
+        # The service and its characteristics are considered to have already been
+        # discovered
         services = client.get_services_by_uuid(service_uuid)
         service = services[0] if services else None
-        return cls(service) if service else None
+        return service_class(service) if service else None
 
     def __init__(self, client, handle, end_group_handle, uuid, primary=True):
-        attribute_type = GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE if primary else GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE
+        attribute_type = (
+            GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE
+            if primary
+            else GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE
+        )
         super().__init__(client, handle, end_group_handle, attribute_type)
-        self.uuid            = uuid
+        self.uuid = uuid
         self.characteristics = []
 
-    async def discover_characteristics(self, uuids=[]):
+    async def discover_characteristics(self, uuids=()):
         return await self.client.discover_characteristics(uuids, self)
 
     def get_characteristics_by_uuid(self, uuid):
@@ -92,29 +139,66 @@ class ServiceProxy(AttributeProxy):
 
 
 class CharacteristicProxy(AttributeProxy):
-    def __init__(self, client, handle, end_group_handle, uuid, properties):
+    properties: Characteristic.Properties
+    descriptors: List[DescriptorProxy]
+    subscribers: Dict[Any, Callable]
+
+    def __init__(
+        self,
+        client,
+        handle,
+        end_group_handle,
+        uuid,
+        properties: int,
+    ):
         super().__init__(client, handle, end_group_handle, uuid)
-        self.uuid                   = uuid
-        self.properties             = properties
-        self.descriptors            = []
+        self.uuid = uuid
+        self.properties = Characteristic.Properties(properties)
+        self.descriptors = []
         self.descriptors_discovered = False
+        self.subscribers = {}  # Map from subscriber to proxy subscriber
 
     def get_descriptor(self, descriptor_type):
         for descriptor in self.descriptors:
             if descriptor.type == descriptor_type:
                 return descriptor
 
+        return None
+
     async def discover_descriptors(self):
         return await self.client.discover_descriptors(self)
 
-    async def subscribe(self, subscriber=None):
-        return await self.client.subscribe(self, subscriber)
+    async def subscribe(
+        self, subscriber: Optional[Callable] = None, prefer_notify=True
+    ):
+        if subscriber is not None:
+            if subscriber in self.subscribers:
+                # We already have a proxy subscriber
+                subscriber = self.subscribers[subscriber]
+            else:
+                # Create and register a proxy that will decode the value
+                original_subscriber = subscriber
+
+                def on_change(value):
+                    original_subscriber(self.decode_value(value))
+
+                self.subscribers[subscriber] = on_change
+                subscriber = on_change
+
+        return await self.client.subscribe(self, subscriber, prefer_notify)
 
     async def unsubscribe(self, subscriber=None):
+        if subscriber in self.subscribers:
+            subscriber = self.subscribers.pop(subscriber)
+
         return await self.client.unsubscribe(self, subscriber)
 
     def __str__(self):
-        return f'Characteristic(handle=0x{self.handle:04X}, uuid={self.uuid}, properties={Characteristic.properties_as_string(self.properties)})'
+        return (
+            f'Characteristic(handle=0x{self.handle:04X}, '
+            f'uuid={self.uuid}, '
+            f'{self.properties!s})'
+        )
 
 
 class DescriptorProxy(AttributeProxy):
@@ -129,6 +213,7 @@ class ProfileServiceProxy:
     '''
     Base class for profile-specific service proxies
     '''
+
     @classmethod
     def from_client(cls, client):
         return ServiceProxy.from_client(cls, client, cls.SERVICE_CLASS.UUID)
@@ -138,51 +223,65 @@ class ProfileServiceProxy:
 # GATT Client
 # -----------------------------------------------------------------------------
 class Client:
+    services: List[ServiceProxy]
+    cached_values: Dict[int, Tuple[datetime, bytes]]
+
     def __init__(self, connection):
-        self.connection               = connection
-        self.mtu                      = ATT_DEFAULT_MTU
-        self.mtu_exchange_done        = False
-        self.request_semaphore        = asyncio.Semaphore(1)
-        self.pending_request          = None
-        self.pending_response         = None
-        self.notification_subscribers = {}  # Notification subscribers, by attribute handle
-        self.indication_subscribers   = {}  # Indication subscribers, by attribute handle
-        self.services                 = []
+        self.connection = connection
+        self.mtu_exchange_done = False
+        self.request_semaphore = asyncio.Semaphore(1)
+        self.pending_request = None
+        self.pending_response = None
+        self.notification_subscribers = (
+            {}
+        )  # Notification subscribers, by attribute handle
+        self.indication_subscribers = {}  # Indication subscribers, by attribute handle
+        self.services = []
+        self.cached_values = {}
 
     def send_gatt_pdu(self, pdu):
         self.connection.send_l2cap_pdu(ATT_CID, pdu)
 
     async def send_command(self, command):
-        logger.debug(f'GATT Command from client: [0x{self.connection.handle:04X}] {command}')
+        logger.debug(
+            f'GATT Command from client: [0x{self.connection.handle:04X}] {command}'
+        )
         self.send_gatt_pdu(command.to_bytes())
 
     async def send_request(self, request):
-        logger.debug(f'GATT Request from client: [0x{self.connection.handle:04X}] {request}')
+        logger.debug(
+            f'GATT Request from client: [0x{self.connection.handle:04X}] {request}'
+        )
 
         # Wait until we can send (only one pending command at a time for the connection)
         response = None
         async with self.request_semaphore:
-            assert(self.pending_request is None)
-            assert(self.pending_response is None)
+            assert self.pending_request is None
+            assert self.pending_response is None
 
             # Create a future value to hold the eventual response
             self.pending_response = asyncio.get_running_loop().create_future()
-            self.pending_request  = request
+            self.pending_request = request
 
             try:
                 self.send_gatt_pdu(request.to_bytes())
-                response = await asyncio.wait_for(self.pending_response, GATT_REQUEST_TIMEOUT)
-            except asyncio.TimeoutError:
+                response = await asyncio.wait_for(
+                    self.pending_response, GATT_REQUEST_TIMEOUT
+                )
+            except asyncio.TimeoutError as error:
                 logger.warning(color('!!! GATT Request timeout', 'red'))
-                raise TimeoutError(f'GATT timeout for {request.name}')
+                raise core.TimeoutError(f'GATT timeout for {request.name}') from error
             finally:
-                self.pending_request  = None
+                self.pending_request = None
                 self.pending_response = None
 
         return response
 
     def send_confirmation(self, confirmation):
-        logger.debug(f'GATT Confirmation from client: [0x{self.connection.handle:04X}] {confirmation}')
+        logger.debug(
+            f'GATT Confirmation from client: [0x{self.connection.handle:04X}] '
+            f'{confirmation}'
+        )
         self.send_gatt_pdu(confirmation.to_bytes())
 
     async def request_mtu(self, mtu):
@@ -194,31 +293,66 @@ class Client:
 
         # We can only send one request per connection
         if self.mtu_exchange_done:
-            return
+            return self.connection.att_mtu
 
         # Send the request
         self.mtu_exchange_done = True
-        response = await self.send_request(ATT_Exchange_MTU_Request(client_rx_mtu = mtu))
+        response = await self.send_request(ATT_Exchange_MTU_Request(client_rx_mtu=mtu))
         if response.op_code == ATT_ERROR_RESPONSE:
             raise ProtocolError(
                 response.error_code,
                 'att',
                 ATT_PDU.error_name(response.error_code),
-                response
+                response,
             )
 
-        self.mtu = max(ATT_DEFAULT_MTU, response.server_rx_mtu)
-        return self.mtu
+        # Compute the final MTU
+        self.connection.att_mtu = min(mtu, response.server_rx_mtu)
+
+        return self.connection.att_mtu
 
     def get_services_by_uuid(self, uuid):
         return [service for service in self.services if service.uuid == uuid]
 
-    def get_characteristics_by_uuid(self, uuid, service = None):
+    def get_characteristics_by_uuid(self, uuid, service=None):
         services = [service] if service else self.services
-        return [c for c in [c for s in services for c in s.characteristics] if c.uuid == uuid]
+        return [
+            c
+            for c in [c for s in services for c in s.characteristics]
+            if c.uuid == uuid
+        ]
+
+    def get_attribute_grouping(
+        self, attribute_handle: int
+    ) -> Optional[
+        Union[
+            ServiceProxy,
+            Tuple[ServiceProxy, CharacteristicProxy],
+            Tuple[ServiceProxy, CharacteristicProxy, DescriptorProxy],
+        ]
+    ]:
+        """
+        Get the attribute(s) associated with an attribute handle
+        """
+        for service in self.services:
+            if service.handle == attribute_handle:
+                return service
+            if service.handle <= attribute_handle <= service.end_group_handle:
+                for characteristic in service.characteristics:
+                    if characteristic.handle == attribute_handle:
+                        return (service, characteristic)
+                    if (
+                        characteristic.handle
+                        <= attribute_handle
+                        <= characteristic.end_group_handle
+                    ):
+                        for descriptor in characteristic.descriptors:
+                            if descriptor.handle == attribute_handle:
+                                return (service, characteristic, descriptor)
+        return None
 
     def on_service_discovered(self, service):
-        ''' Add a service to the service list if it wasn't already there '''
+        '''Add a service to the service list if it wasn't already there'''
         already_known = False
         for existing_service in self.services:
             if existing_service.handle == service.handle:
@@ -227,7 +361,7 @@ class Client:
         if not already_known:
             self.services.append(service)
 
-    async def discover_services(self, uuids = None):
+    async def discover_services(self, uuids=None) -> List[ServiceProxy]:
         '''
         See Vol 3, Part G - 4.4.1 Discover All Primary Services
         '''
@@ -236,9 +370,9 @@ class Client:
         while starting_handle < 0xFFFF:
             response = await self.send_request(
                 ATT_Read_By_Group_Type_Request(
-                    starting_handle      = starting_handle,
-                    ending_handle        = 0xFFFF,
-                    attribute_group_type = GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE
+                    starting_handle=starting_handle,
+                    ending_handle=0xFFFF,
+                    attribute_group_type=GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
                 )
             )
             if response is None:
@@ -249,16 +383,30 @@ class Client:
             if response.op_code == ATT_ERROR_RESPONSE:
                 if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                     # Unexpected end
-                    logger.waning(f'!!! unexpected error while discovering services: {HCI_Constant.error_name(response.error_code)}')
-                    # TODO raise appropriate exception
-                    return
+                    logger.warning(
+                        '!!! unexpected error while discovering services: '
+                        f'{HCI_Constant.error_name(response.error_code)}'
+                    )
+                    raise ATT_Error(
+                        error_code=response.error_code,
+                        message='Unexpected error while discovering services',
+                    )
                 break
 
-            for attribute_handle, end_group_handle, attribute_value in response.attributes:
-                if attribute_handle < starting_handle or end_group_handle < attribute_handle:
+            for (
+                attribute_handle,
+                end_group_handle,
+                attribute_value,
+            ) in response.attributes:
+                if (
+                    attribute_handle < starting_handle
+                    or end_group_handle < attribute_handle
+                ):
                     # Something's not right
-                    logger.warning(f'bogus handle values: {attribute_handle} {end_group_handle}')
-                    return
+                    logger.warning(
+                        f'bogus handle values: {attribute_handle} {end_group_handle}'
+                    )
+                    return []
 
                 # Create a service proxy for this service
                 service = ServiceProxy(
@@ -266,7 +414,7 @@ class Client:
                     attribute_handle,
                     end_group_handle,
                     UUID.from_bytes(attribute_value),
-                    True
+                    True,
                 )
 
                 # Filter out returned services based on the given uuids list
@@ -291,7 +439,7 @@ class Client:
         '''
 
         # Force uuid to be a UUID object
-        if type(uuid) is str:
+        if isinstance(uuid, str):
             uuid = UUID(uuid)
 
         starting_handle = 0x0001
@@ -299,10 +447,10 @@ class Client:
         while starting_handle < 0xFFFF:
             response = await self.send_request(
                 ATT_Find_By_Type_Value_Request(
-                    starting_handle = starting_handle,
-                    ending_handle   = 0xFFFF,
-                    attribute_type  = GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
-                    attribute_value = uuid.to_pdu_bytes()
+                    starting_handle=starting_handle,
+                    ending_handle=0xFFFF,
+                    attribute_type=GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
+                    attribute_value=uuid.to_pdu_bytes(),
                 )
             )
             if response is None:
@@ -313,19 +461,29 @@ class Client:
             if response.op_code == ATT_ERROR_RESPONSE:
                 if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                     # Unexpected end
-                    logger.waning(f'!!! unexpected error while discovering services: {HCI_Constant.error_name(response.error_code)}')
+                    logger.warning(
+                        '!!! unexpected error while discovering services: '
+                        f'{HCI_Constant.error_name(response.error_code)}'
+                    )
                     # TODO raise appropriate exception
                     return
                 break
 
             for attribute_handle, end_group_handle in response.handles_information:
-                if attribute_handle < starting_handle or end_group_handle < attribute_handle:
+                if (
+                    attribute_handle < starting_handle
+                    or end_group_handle < attribute_handle
+                ):
                     # Something's not right
-                    logger.warning(f'bogus handle values: {attribute_handle} {end_group_handle}')
+                    logger.warning(
+                        f'bogus handle values: {attribute_handle} {end_group_handle}'
+                    )
                     return
 
                 # Create a service proxy for this service
-                service = ServiceProxy(self, attribute_handle, end_group_handle, uuid, True)
+                service = ServiceProxy(
+                    self, attribute_handle, end_group_handle, uuid, True
+                )
 
                 # Add the service to the peer's service list
                 services.append(service)
@@ -344,37 +502,40 @@ class Client:
 
         return services
 
-    async def discover_included_services(self, service):
+    async def discover_included_services(self, _service):
         '''
         See Vol 3, Part G - 4.5.1 Find Included Services
         '''
         # TODO
         return []
 
-    async def discover_characteristics(self, uuids, service):
+    async def discover_characteristics(
+        self, uuids, service: Optional[ServiceProxy]
+    ) -> List[CharacteristicProxy]:
         '''
-        See Vol 3, Part G - 4.6.1 Discover All Characteristics of a Service and 4.6.2 Discover Characteristics by UUID
+        See Vol 3, Part G - 4.6.1 Discover All Characteristics of a Service and 4.6.2
+        Discover Characteristics by UUID
         '''
 
         # Cast the UUIDs type from string to object if needed
-        uuids = [UUID(uuid) if type(uuid) is str else uuid for uuid in uuids]
+        uuids = [UUID(uuid) if isinstance(uuid, str) else uuid for uuid in uuids]
 
         # Decide which services to discover for
         services = [service] if service else self.services
 
         # Perform characteristic discovery for each service
-        discovered_characteristics = []
+        discovered_characteristics: List[CharacteristicProxy] = []
         for service in services:
             starting_handle = service.handle
-            ending_handle   = service.end_group_handle
+            ending_handle = service.end_group_handle
 
-            characteristics = []
+            characteristics: List[CharacteristicProxy] = []
             while starting_handle <= ending_handle:
                 response = await self.send_request(
                     ATT_Read_By_Type_Request(
-                        starting_handle = starting_handle,
-                        ending_handle   = ending_handle,
-                        attribute_type  = GATT_CHARACTERISTIC_ATTRIBUTE_TYPE
+                        starting_handle=starting_handle,
+                        ending_handle=ending_handle,
+                        attribute_type=GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
                     )
                 )
                 if response is None:
@@ -385,9 +546,14 @@ class Client:
                 if response.op_code == ATT_ERROR_RESPONSE:
                     if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                         # Unexpected end
-                        logger.warning(f'!!! unexpected error while discovering characteristics: {HCI_Constant.error_name(response.error_code)}')
-                        # TODO raise appropriate exception
-                        return
+                        logger.warning(
+                            '!!! unexpected error while discovering characteristics: '
+                            f'{HCI_Constant.error_name(response.error_code)}'
+                        )
+                        raise ATT_Error(
+                            error_code=response.error_code,
+                            message='Unexpected error while discovering characteristics',
+                        )
                     break
 
                 # Stop if for some reason the list was empty
@@ -403,7 +569,9 @@ class Client:
 
                     properties, handle = struct.unpack_from('<BH', attribute_value)
                     characteristic_uuid = UUID.from_bytes(attribute_value[3:])
-                    characteristic = CharacteristicProxy(self, handle, 0, characteristic_uuid, properties)
+                    characteristic = CharacteristicProxy(
+                        self, handle, 0, characteristic_uuid, properties
+                    )
 
                     # Set the previous characteristic's end handle
                     if characteristics:
@@ -419,31 +587,37 @@ class Client:
                 characteristics[-1].end_group_handle = service.end_group_handle
 
             # Set the service's characteristics
-            characteristics = [c for c in characteristics if not uuids or c.uuid in uuids]
+            characteristics = [
+                c for c in characteristics if not uuids or c.uuid in uuids
+            ]
             service.characteristics = characteristics
             discovered_characteristics.extend(characteristics)
 
         return discovered_characteristics
 
-    async def discover_descriptors(self, characteristic = None, start_handle = None, end_handle = None):
+    async def discover_descriptors(
+        self,
+        characteristic: Optional[CharacteristicProxy] = None,
+        start_handle=None,
+        end_handle=None,
+    ) -> List[DescriptorProxy]:
         '''
         See Vol 3, Part G - 4.7.1 Discover All Characteristic Descriptors
         '''
         if characteristic:
             starting_handle = characteristic.handle + 1
-            ending_handle   = characteristic.end_group_handle
+            ending_handle = characteristic.end_group_handle
         elif start_handle and end_handle:
             starting_handle = start_handle
-            ending_handle   = end_handle
+            ending_handle = end_handle
         else:
             return []
 
-        descriptors = []
+        descriptors: List[DescriptorProxy] = []
         while starting_handle <= ending_handle:
             response = await self.send_request(
                 ATT_Find_Information_Request(
-                    starting_handle = starting_handle,
-                    ending_handle   = ending_handle
+                    starting_handle=starting_handle, ending_handle=ending_handle
                 )
             )
             if response is None:
@@ -454,7 +628,10 @@ class Client:
             if response.op_code == ATT_ERROR_RESPONSE:
                 if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                     # Unexpected end
-                    logger.warning(f'!!! unexpected error while discovering descriptors: {HCI_Constant.error_name(response.error_code)}')
+                    logger.warning(
+                        '!!! unexpected error while discovering descriptors: '
+                        f'{HCI_Constant.error_name(response.error_code)}'
+                    )
                     # TODO raise appropriate exception
                     return []
                 break
@@ -470,7 +647,9 @@ class Client:
                     logger.warning(f'bogus handle value: {attribute_handle}')
                     return []
 
-                descriptor = DescriptorProxy(self, attribute_handle, UUID.from_bytes(attribute_uuid))
+                descriptor = DescriptorProxy(
+                    self, attribute_handle, UUID.from_bytes(attribute_uuid)
+                )
                 descriptors.append(descriptor)
                 # TODO: read descriptor value
 
@@ -488,13 +667,12 @@ class Client:
         Discover all attributes, regardless of type
         '''
         starting_handle = 0x0001
-        ending_handle   = 0xFFFF
+        ending_handle = 0xFFFF
         attributes = []
         while True:
             response = await self.send_request(
                 ATT_Find_Information_Request(
-                    starting_handle = starting_handle,
-                    ending_handle   = ending_handle
+                    starting_handle=starting_handle, ending_handle=ending_handle
                 )
             )
             if response is None:
@@ -504,7 +682,10 @@ class Client:
             if response.op_code == ATT_ERROR_RESPONSE:
                 if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                     # Unexpected end
-                    logger.warning(f'!!! unexpected error while discovering attributes: {HCI_Constant.error_name(response.error_code)}')
+                    logger.warning(
+                        '!!! unexpected error while discovering attributes: '
+                        f'{HCI_Constant.error_name(response.error_code)}'
+                    )
                     return []
                 break
 
@@ -514,7 +695,9 @@ class Client:
                     logger.warning(f'bogus handle value: {attribute_handle}')
                     return []
 
-                attribute = AttributeProxy(self, attribute_handle, 0, UUID.from_bytes(attribute_uuid))
+                attribute = AttributeProxy(
+                    self, attribute_handle, 0, UUID.from_bytes(attribute_uuid)
+                )
                 attributes.append(attribute)
 
             # Move on to the next attributes
@@ -522,58 +705,85 @@ class Client:
 
         return attributes
 
-    async def subscribe(self, characteristic, subscriber=None):
-        # If we haven't already discovered the descriptors for this characteristic, do it now
+    async def subscribe(self, characteristic, subscriber=None, prefer_notify=True):
+        # If we haven't already discovered the descriptors for this characteristic,
+        # do it now
         if not characteristic.descriptors_discovered:
             await self.discover_descriptors(characteristic)
 
         # Look for the CCCD descriptor
-        cccd = characteristic.get_descriptor(GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR)
+        cccd = characteristic.get_descriptor(
+            GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR
+        )
         if not cccd:
             logger.warning('subscribing to characteristic with no CCCD descriptor')
             return
 
-        # Set the subscription bits and select the subscriber set
-        bits = 0
-        subscriber_sets = []
-        if characteristic.properties & Characteristic.NOTIFY:
-            bits |= 0x0001
-            subscriber_sets.append(self.notification_subscribers.setdefault(characteristic.handle, set()))
-        if characteristic.properties & Characteristic.INDICATE:
-            bits |= 0x0002
-            subscriber_sets.append(self.indication_subscribers.setdefault(characteristic.handle, set()))
+        if (
+            characteristic.properties & Characteristic.Properties.NOTIFY
+            and characteristic.properties & Characteristic.Properties.INDICATE
+        ):
+            if prefer_notify:
+                bits = ClientCharacteristicConfigurationBits.NOTIFICATION
+                subscribers = self.notification_subscribers
+            else:
+                bits = ClientCharacteristicConfigurationBits.INDICATION
+                subscribers = self.indication_subscribers
+        elif characteristic.properties & Characteristic.Properties.NOTIFY:
+            bits = ClientCharacteristicConfigurationBits.NOTIFICATION
+            subscribers = self.notification_subscribers
+        elif characteristic.properties & Characteristic.Properties.INDICATE:
+            bits = ClientCharacteristicConfigurationBits.INDICATION
+            subscribers = self.indication_subscribers
+        else:
+            raise InvalidStateError("characteristic is not notify or indicate")
 
         # Add subscribers to the sets
-        for subscriber_set in subscriber_sets:
-            if subscriber is not None:
-                subscriber_set.add(subscriber)
-            subscriber_set.add(lambda value: characteristic.emit('update', self.connection, value))
+        subscriber_set = subscribers.setdefault(characteristic.handle, set())
+        if subscriber is not None:
+            subscriber_set.add(subscriber)
+        # Add the characteristic as a subscriber, which will result in the
+        # characteristic emitting an 'update' event when a notification or indication
+        # is received
+        subscriber_set.add(characteristic)
 
         await self.write_value(cccd, struct.pack('<H', bits), with_response=True)
 
     async def unsubscribe(self, characteristic, subscriber=None):
-        # If we haven't already discovered the descriptors for this characteristic, do it now
+        # If we haven't already discovered the descriptors for this characteristic,
+        # do it now
         if not characteristic.descriptors_discovered:
             await self.discover_descriptors(characteristic)
 
         # Look for the CCCD descriptor
-        cccd = characteristic.get_descriptor(GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR)
+        cccd = characteristic.get_descriptor(
+            GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR
+        )
         if not cccd:
             logger.warning('unsubscribing from characteristic with no CCCD descriptor')
             return
 
         if subscriber is not None:
             # Remove matching subscriber from subscriber sets
-            for subscriber_set in (self.notification_subscribers, self.indication_subscribers):
+            for subscriber_set in (
+                self.notification_subscribers,
+                self.indication_subscribers,
+            ):
                 subscribers = subscriber_set.get(characteristic.handle, [])
                 if subscriber in subscribers:
                     subscribers.remove(subscriber)
+
+                    # Cleanup if we removed the last one
+                    if not subscribers:
+                        del subscriber_set[characteristic.handle]
         else:
             # Remove all subscribers for this attribute from the sets!
             self.notification_subscribers.pop(characteristic.handle, None)
             self.indication_subscribers.pop(characteristic.handle, None)
 
-        await self.write_value(cccd, b'\x00\x00', with_response=True)
+        if not self.notification_subscribers and not self.indication_subscribers:
+            # No more subscribers left
+            await self.write_value(cccd, b'\x00\x00', with_response=True)
 
     async def read_value(self, attribute, no_long_read=False):
         '''
@@ -583,8 +793,10 @@ class Client:
         '''
 
         # Send a request to read
-        attribute_handle = attribute if type(attribute) is int else attribute.handle
-        response = await self.send_request(ATT_Read_Request(attribute_handle = attribute_handle))
+        attribute_handle = attribute if isinstance(attribute, int) else attribute.handle
+        response = await self.send_request(
+            ATT_Read_Request(attribute_handle=attribute_handle)
+        )
         if response is None:
             raise TimeoutError('read timeout')
         if response.op_code == ATT_ERROR_RESPONSE:
@@ -592,39 +804,45 @@ class Client:
                 response.error_code,
                 'att',
                 ATT_PDU.error_name(response.error_code),
-                response
+                response,
             )
 
         # If the value is the max size for the MTU, try to read more unless the caller
         # specifically asked not to do that
         attribute_value = response.attribute_value
-        if not no_long_read and len(attribute_value) == self.mtu - 1:
+        if not no_long_read and len(attribute_value) == self.connection.att_mtu - 1:
             logger.debug('using READ BLOB to get the rest of the value')
             offset = len(attribute_value)
             while True:
                 response = await self.send_request(
-                    ATT_Read_Blob_Request(attribute_handle = attribute_handle, value_offset = offset)
+                    ATT_Read_Blob_Request(
+                        attribute_handle=attribute_handle, value_offset=offset
+                    )
                 )
                 if response is None:
                     raise TimeoutError('read timeout')
                 if response.op_code == ATT_ERROR_RESPONSE:
-                    if response.error_code == ATT_ATTRIBUTE_NOT_LONG_ERROR or response.error_code == ATT_INVALID_OFFSET_ERROR:
+                    if response.error_code in (
+                        ATT_ATTRIBUTE_NOT_LONG_ERROR,
+                        ATT_INVALID_OFFSET_ERROR,
+                    ):
                         break
                     raise ProtocolError(
                         response.error_code,
                         'att',
                         ATT_PDU.error_name(response.error_code),
-                        response
+                        response,
                     )
 
                 part = response.part_attribute_value
                 attribute_value += part
 
-                if len(part) < self.mtu - 1:
+                if len(part) < self.connection.att_mtu - 1:
                     break
 
                 offset += len(part)
 
+        self.cache_value(attribute_handle, attribute_value)
         # Return the value as bytes
         return attribute_value
 
@@ -635,18 +853,18 @@ class Client:
 
         if service is None:
             starting_handle = 0x0001
-            ending_handle   = 0xFFFF
+            ending_handle = 0xFFFF
         else:
             starting_handle = service.handle
-            ending_handle   = service.end_group_handle
+            ending_handle = service.end_group_handle
 
         characteristics_values = []
         while starting_handle <= ending_handle:
             response = await self.send_request(
                 ATT_Read_By_Type_Request(
-                    starting_handle = starting_handle,
-                    ending_handle   = ending_handle,
-                    attribute_type  = uuid
+                    starting_handle=starting_handle,
+                    ending_handle=ending_handle,
+                    attribute_type=uuid,
                 )
             )
             if response is None:
@@ -657,7 +875,10 @@ class Client:
             if response.op_code == ATT_ERROR_RESPONSE:
                 if response.error_code != ATT_ATTRIBUTE_NOT_FOUND_ERROR:
                     # Unexpected end
-                    logger.warning(f'!!! unexpected error while reading characteristics: {HCI_Constant.error_name(response.error_code)}')
+                    logger.warning(
+                        '!!! unexpected error while reading characteristics: '
+                        f'{HCI_Constant.error_name(response.error_code)}'
+                    )
                     # TODO raise appropriate exception
                     return []
                 break
@@ -682,47 +903,54 @@ class Client:
 
     async def write_value(self, attribute, value, with_response=False):
         '''
-        See Vol 3, Part G - 4.9.1 Write Without Response & 4.9.3 Write Characteristic Value
+        See Vol 3, Part G - 4.9.1 Write Without Response & 4.9.3 Write Characteristic
+        Value
 
         `attribute` can be an Attribute object, or a handle value
         '''
 
         # Send a request or command to write
-        attribute_handle = attribute if type(attribute) is int else attribute.handle
+        attribute_handle = attribute if isinstance(attribute, int) else attribute.handle
         if with_response:
             response = await self.send_request(
                 ATT_Write_Request(
-                    attribute_handle = attribute_handle,
-                    attribute_value  = value
+                    attribute_handle=attribute_handle, attribute_value=value
                 )
             )
             if response.op_code == ATT_ERROR_RESPONSE:
                 raise ProtocolError(
                     response.error_code,
                     'att',
-                    ATT_PDU.error_name(response.error_code), response
+                    ATT_PDU.error_name(response.error_code),
+                    response,
                 )
         else:
             await self.send_command(
                 ATT_Write_Command(
-                    attribute_handle = attribute_handle,
-                    attribute_value  = value
+                    attribute_handle=attribute_handle, attribute_value=value
                 )
             )
 
     def on_gatt_pdu(self, att_pdu):
-        logger.debug(f'GATT Response to client: [0x{self.connection.handle:04X}] {att_pdu}')
+        logger.debug(
+            f'GATT Response to client: [0x{self.connection.handle:04X}] {att_pdu}'
+        )
         if att_pdu.op_code in ATT_RESPONSES:
             if self.pending_request is None:
                 # Not expected!
                 logger.warning('!!! unexpected response, there is no pending request')
                 return
 
-            # Sanity check: the response should match the pending request unless it is an error response
+            # Sanity check: the response should match the pending request unless it is
+            # an error response
             if att_pdu.op_code != ATT_ERROR_RESPONSE:
-                expected_response_name = self.pending_request.name.replace('_REQUEST', '_RESPONSE')
+                expected_response_name = self.pending_request.name.replace(
+                    '_REQUEST', '_RESPONSE'
+                )
                 if att_pdu.name != expected_response_name:
-                    logger.warning(f'!!! mismatched response: expected {expected_response_name}')
+                    logger.warning(
+                        f'!!! mismatched response: expected {expected_response_name}'
+                    )
                     return
 
             # Return the response to the coroutine that is waiting for it
@@ -733,23 +961,48 @@ class Client:
             if handler is not None:
                 handler(att_pdu)
             else:
-                logger.warning(f'{color(f"--- Ignoring GATT Response from [0x{self.connection.handle:04X}]:", "red")} {att_pdu}')
+                logger.warning(
+                    color(
+                        '--- Ignoring GATT Response from '
+                        f'[0x{self.connection.handle:04X}]: ',
+                        'red',
+                    )
+                    + str(att_pdu)
+                )
 
     def on_att_handle_value_notification(self, notification):
         # Call all subscribers
-        subscribers = self.notification_subscribers.get(notification.attribute_handle, [])
+        subscribers = self.notification_subscribers.get(
+            notification.attribute_handle, []
+        )
         if not subscribers:
             logger.warning('!!! received notification with no subscriber')
+
+        self.cache_value(notification.attribute_handle, notification.attribute_value)
         for subscriber in subscribers:
-            subscriber(notification.attribute_value)
+            if callable(subscriber):
+                subscriber(notification.attribute_value)
+            else:
+                subscriber.emit('update', notification.attribute_value)
 
     def on_att_handle_value_indication(self, indication):
         # Call all subscribers
         subscribers = self.indication_subscribers.get(indication.attribute_handle, [])
         if not subscribers:
             logger.warning('!!! received indication with no subscriber')
+
+        self.cache_value(indication.attribute_handle, indication.attribute_value)
         for subscriber in subscribers:
-            subscriber(indication.attribute_value)
+            if callable(subscriber):
+                subscriber(indication.attribute_value)
+            else:
+                subscriber.emit('update', indication.attribute_value)
 
         # Confirm that we received the indication
         self.send_confirmation(ATT_Handle_Value_Confirmation())
+
+    def cache_value(self, attribute_handle: int, value: bytes):
+        self.cached_values[attribute_handle] = (
+            datetime.now(),
+            value,
+        )

bumble/gatt_server.py

@@ -26,13 +26,52 @@
 import asyncio
 import logging
 from collections import defaultdict
+import struct
+from typing import List, Tuple, Optional, TypeVar, Type
 from pyee import EventEmitter
-from colors import color
 
-from .core import *
-from .hci import *
-from .att import *
-from .gatt import *
+from .colors import color
+from .core import UUID
+from .att import (
+    ATT_ATTRIBUTE_NOT_FOUND_ERROR,
+    ATT_ATTRIBUTE_NOT_LONG_ERROR,
+    ATT_CID,
+    ATT_DEFAULT_MTU,
+    ATT_INVALID_ATTRIBUTE_LENGTH_ERROR,
+    ATT_INVALID_HANDLE_ERROR,
+    ATT_INVALID_OFFSET_ERROR,
+    ATT_REQUEST_NOT_SUPPORTED_ERROR,
+    ATT_REQUESTS,
+    ATT_UNLIKELY_ERROR_ERROR,
+    ATT_UNSUPPORTED_GROUP_TYPE_ERROR,
+    ATT_Error,
+    ATT_Error_Response,
+    ATT_Exchange_MTU_Response,
+    ATT_Find_By_Type_Value_Response,
+    ATT_Find_Information_Response,
+    ATT_Handle_Value_Indication,
+    ATT_Handle_Value_Notification,
+    ATT_Read_Blob_Response,
+    ATT_Read_By_Group_Type_Response,
+    ATT_Read_By_Type_Response,
+    ATT_Read_Response,
+    ATT_Write_Response,
+    Attribute,
+)
+from .gatt import (
+    GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
+    GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
+    GATT_MAX_ATTRIBUTE_VALUE_SIZE,
+    GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
+    GATT_REQUEST_TIMEOUT,
+    GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
+    Characteristic,
+    CharacteristicDeclaration,
+    CharacteristicValue,
+    Descriptor,
+    Service,
+)
+
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -40,27 +79,49 @@ from .gatt import *
 logger = logging.getLogger(__name__)
 
 
+# -----------------------------------------------------------------------------
+# Constants
+# -----------------------------------------------------------------------------
+GATT_SERVER_DEFAULT_MAX_MTU = 517
+
+
 # -----------------------------------------------------------------------------
 # GATT Server
 # -----------------------------------------------------------------------------
 class Server(EventEmitter):
+    attributes: List[Attribute]
+
     def __init__(self, device):
         super().__init__()
-        self.device                = device
-        self.attributes            = []  # Attributes, ordered by increasing handle values
-        self.attributes_by_handle  = {}  # Map for fast attribute access by handle
-        self.max_mtu               = 23  # FIXME: 517  # The max MTU we're willing to negotiate
-        self.subscribers           = {}  # Map of subscriber states by connection handle and attribute handle
-        self.mtus                  = {}  # Map of ATT MTU values by connection handle
+        self.device = device
+        self.attributes = []  # Attributes, ordered by increasing handle values
+        self.attributes_by_handle = {}  # Map for fast attribute access by handle
+        self.max_mtu = (
+            GATT_SERVER_DEFAULT_MAX_MTU  # The max MTU we're willing to negotiate
+        )
+        self.subscribers = (
+            {}
+        )  # Map of subscriber states by connection handle and attribute handle
         self.indication_semaphores = defaultdict(lambda: asyncio.Semaphore(1))
         self.pending_confirmations = defaultdict(lambda: None)
 
+    def __str__(self):
+        return "\n".join(map(str, self.attributes))
+
     def send_gatt_pdu(self, connection_handle, pdu):
         self.device.send_l2cap_pdu(connection_handle, ATT_CID, pdu)
 
     def next_handle(self):
         return 1 + len(self.attributes)
 
+    def get_advertising_service_data(self):
+        return {
+            attribute: data
+            for attribute in self.attributes
+            if isinstance(attribute, Service)
+            and (data := attribute.get_advertising_data())
+        }
+
     def get_attribute(self, handle):
         attribute = self.attributes_by_handle.get(handle)
         if attribute:
@@ -74,15 +135,90 @@ class Server(EventEmitter):
                 return attribute
         return None
 
+    AttributeGroupType = TypeVar('AttributeGroupType', Service, Characteristic)
+
+    def get_attribute_group(
+        self, handle: int, group_type: Type[AttributeGroupType]
+    ) -> Optional[AttributeGroupType]:
+        return next(
+            (
+                attribute
+                for attribute in self.attributes
+                if isinstance(attribute, group_type)
+                and attribute.handle <= handle <= attribute.end_group_handle
+            ),
+            None,
+        )
+
+    def get_service_attribute(self, service_uuid: UUID) -> Optional[Service]:
+        return next(
+            (
+                attribute
+                for attribute in self.attributes
+                if attribute.type == GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE
+                and isinstance(attribute, Service)
+                and attribute.uuid == service_uuid
+            ),
+            None,
+        )
+
+    def get_characteristic_attributes(
+        self, service_uuid: UUID, characteristic_uuid: UUID
+    ) -> Optional[Tuple[CharacteristicDeclaration, Characteristic]]:
+        service_handle = self.get_service_attribute(service_uuid)
+        if not service_handle:
+            return None
+
+        return next(
+            (
+                (attribute, self.get_attribute(attribute.characteristic.handle))
+                for attribute in map(
+                    self.get_attribute,
+                    range(service_handle.handle, service_handle.end_group_handle + 1),
+                )
+                if attribute.type == GATT_CHARACTERISTIC_ATTRIBUTE_TYPE
+                and attribute.characteristic.uuid == characteristic_uuid
+            ),
+            None,
+        )
+
+    def get_descriptor_attribute(
+        self, service_uuid: UUID, characteristic_uuid: UUID, descriptor_uuid: UUID
+    ) -> Optional[Descriptor]:
+        characteristics = self.get_characteristic_attributes(
+            service_uuid, characteristic_uuid
+        )
+        if not characteristics:
+            return None
+
+        (_, characteristic_value) = characteristics
+
+        return next(
+            (
+                attribute
+                for attribute in map(
+                    self.get_attribute,
+                    range(
+                        characteristic_value.handle + 1,
+                        characteristic_value.end_group_handle + 1,
+                    ),
+                )
+                if attribute.type == descriptor_uuid
+            ),
+            None,
+        )
+
     def add_attribute(self, attribute):
         # Assign a handle to this attribute
         attribute.handle = self.next_handle()
-        attribute.end_group_handle = attribute.handle  # TODO: keep track of descriptors in the group
+        attribute.end_group_handle = (
+            attribute.handle
+        )  # TODO: keep track of descriptors in the group
 
         # Add this attribute to the list
         self.attributes.append(attribute)
 
-    def add_service(self, service):
+    def add_service(self, service: Service):
         # Add the service attribute to the DB
         self.add_attribute(service)
 
@@ -90,16 +226,9 @@ class Server(EventEmitter):
 
         # Add all characteristics
         for characteristic in service.characteristics:
-            # Add a Characteristic Declaration (Vol 3, Part G - 3.3.1 Characteristic Declaration)
-            declaration_bytes = struct.pack(
-                '<BH',
-                characteristic.properties,
-                self.next_handle() + 1,  # The value will be the next attribute after this declaration
-            ) + characteristic.uuid.to_pdu_bytes()
-            characteristic_declaration = Attribute(
-                GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
-                Attribute.READABLE,
-                declaration_bytes
+            # Add a Characteristic Declaration
+            characteristic_declaration = CharacteristicDeclaration(
+                characteristic, self.next_handle() + 1
             )
             self.add_attribute(characteristic_declaration)
 
@@ -113,17 +242,29 @@ class Server(EventEmitter):
             # If the characteristic supports subscriptions, add a CCCD descriptor
             # unless there is one already
             if (
-                characteristic.properties & (Characteristic.NOTIFY | Characteristic.INDICATE) and
-                characteristic.get_descriptor(GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR) is None
+                characteristic.properties
+                & (
+                    Characteristic.Properties.NOTIFY
+                    | Characteristic.Properties.INDICATE
+                )
+                and characteristic.get_descriptor(
+                    GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR
+                )
+                is None
             ):
                 self.add_attribute(
+                    # pylint: disable=line-too-long
                     Descriptor(
                         GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
                         Attribute.READABLE | Attribute.WRITEABLE,
                         CharacteristicValue(
-                            read=lambda connection, characteristic=characteristic: self.read_cccd(connection, characteristic),
-                            write=lambda connection, value, characteristic=characteristic: self.write_cccd(connection, characteristic, value)
-                        )
+                            read=lambda connection, characteristic=characteristic: self.read_cccd(
+                                connection, characteristic
+                            ),
+                            write=lambda connection, value, characteristic=characteristic: self.write_cccd(
+                                connection, characteristic, value
+                            ),
+                        ),
                     )
                 )
 
@@ -150,26 +291,39 @@ class Server(EventEmitter):
         return cccd or bytes([0, 0])
 
     def write_cccd(self, connection, characteristic, value):
-        logger.debug(f'Subscription update for connection={connection.handle:04X}, handle={characteristic.handle:04X}: {value.hex()}')
+        logger.debug(
+            f'Subscription update for connection=0x{connection.handle:04X}, '
+            f'handle=0x{characteristic.handle:04X}: {value.hex()}'
+        )
 
         # Sanity check
         if len(value) != 2:
-            logger.warn('CCCD value not 2 bytes long')
+            logger.warning('CCCD value not 2 bytes long')
             return
 
         cccds = self.subscribers.setdefault(connection.handle, {})
         cccds[characteristic.handle] = value
         logger.debug(f'CCCDs: {cccds}')
-        notify_enabled = (value[0] & 0x01 != 0)
-        indicate_enabled = (value[0] & 0x02 != 0)
-        characteristic.emit('subscription', connection, notify_enabled, indicate_enabled)
-        self.emit('characteristic_subscription', connection, characteristic, notify_enabled, indicate_enabled)
+        notify_enabled = value[0] & 0x01 != 0
+        indicate_enabled = value[0] & 0x02 != 0
+        characteristic.emit(
+            'subscription', connection, notify_enabled, indicate_enabled
+        )
+        self.emit(
+            'characteristic_subscription',
+            connection,
+            characteristic,
+            notify_enabled,
+            indicate_enabled,
+        )
 
     def send_response(self, connection, response):
-        logger.debug(f'GATT Response from server: [0x{connection.handle:04X}] {response}')
+        logger.debug(
+            f'GATT Response from server: [0x{connection.handle:04X}] {response}'
+        )
         self.send_gatt_pdu(connection.handle, response.to_bytes())
 
-    async def notify_subscriber(self, connection, attribute, force=False):
+    async def notify_subscriber(self, connection, attribute, value=None, force=False):
         # Check if there's a subscriber
         if not force:
             subscribers = self.subscribers.get(connection.handle)
@@ -178,47 +332,35 @@ class Server(EventEmitter):
                 return
             cccd = subscribers.get(attribute.handle)
             if not cccd:
-                logger.debug(f'not notifying, no subscribers for handle {attribute.handle:04X}')
+                logger.debug(
+                    f'not notifying, no subscribers for handle {attribute.handle:04X}'
+                )
                 return
             if len(cccd) != 2 or (cccd[0] & 0x01 == 0):
                 logger.debug(f'not notifying, cccd={cccd.hex()}')
                 return
 
-        # Get the value
-        value = attribute.read_value(connection)
+        # Get or encode the value
+        value = (
+            attribute.read_value(connection)
+            if value is None
+            else attribute.encode_value(value)
+        )
 
         # Truncate if needed
-        mtu = self.get_mtu(connection)
-        if len(value) > mtu - 3:
-            value = value[:mtu - 3]
+        if len(value) > connection.att_mtu - 3:
+            value = value[: connection.att_mtu - 3]
 
         # Notify
         notification = ATT_Handle_Value_Notification(
-            attribute_handle = attribute.handle,
-            attribute_value  = value
+            attribute_handle=attribute.handle, attribute_value=value
         )
-        logger.debug(f'GATT Notify from server: [0x{connection.handle:04X}] {notification}')
-        self.send_gatt_pdu(connection.handle, notification.to_bytes())
+        logger.debug(
+            f'GATT Notify from server: [0x{connection.handle:04X}] {notification}'
+        )
+        self.send_gatt_pdu(connection.handle, bytes(notification))
 
-    async def notify_subscribers(self, attribute, force=False):
-        # Get all the connections for which there's at least one subscription
-        connections = [
-            connection for connection in [
-                self.device.lookup_connection(connection_handle)
-                for (connection_handle, subscribers) in self.subscribers.items()
-                if force or subscribers.get(attribute.handle)
-            ]
-            if connection is not None
-        ]
-
-        # Notify for each connection
-        if connections:
-            await asyncio.wait([
-                self.notify_subscriber(connection, attribute, force)
-                for connection in connections
-            ])
-
-    async def indicate_subscriber(self, connection, attribute, force=False):
+    async def indicate_subscriber(self, connection, attribute, value=None, force=False):
         # Check if there's a subscriber
         if not force:
             subscribers = self.subscribers.get(connection.handle)
@@ -227,64 +369,84 @@ class Server(EventEmitter):
                 return
             cccd = subscribers.get(attribute.handle)
             if not cccd:
-                logger.debug(f'not indicating, no subscribers for handle {attribute.handle:04X}')
+                logger.debug(
+                    f'not indicating, no subscribers for handle {attribute.handle:04X}'
+                )
                 return
             if len(cccd) != 2 or (cccd[0] & 0x02 == 0):
                 logger.debug(f'not indicating, cccd={cccd.hex()}')
                 return
 
-        # Get the value
-        value = attribute.read_value(connection)
+        # Get or encode the value
+        value = (
+            attribute.read_value(connection)
+            if value is None
+            else attribute.encode_value(value)
+        )
 
         # Truncate if needed
-        mtu = self.get_mtu(connection)
-        if len(value) > mtu - 3:
-            value = value[:mtu - 3]
+        if len(value) > connection.att_mtu - 3:
+            value = value[: connection.att_mtu - 3]
 
         # Indicate
         indication = ATT_Handle_Value_Indication(
-            attribute_handle = attribute.handle,
-            attribute_value  = value
+            attribute_handle=attribute.handle, attribute_value=value
+        )
+        logger.debug(
+            f'GATT Indicate from server: [0x{connection.handle:04X}] {indication}'
         )
-        logger.debug(f'GATT Indicate from server: [0x{connection.handle:04X}] {indication}')
 
         # Wait until we can send (only one pending indication at a time per connection)
         async with self.indication_semaphores[connection.handle]:
-            assert(self.pending_confirmations[connection.handle] is None)
+            assert self.pending_confirmations[connection.handle] is None
 
             # Create a future value to hold the eventual response
-            self.pending_confirmations[connection.handle] = asyncio.get_running_loop().create_future()
+            self.pending_confirmations[
+                connection.handle
+            ] = asyncio.get_running_loop().create_future()
 
             try:
                 self.send_gatt_pdu(connection.handle, indication.to_bytes())
-                await asyncio.wait_for(self.pending_confirmations[connection.handle], GATT_REQUEST_TIMEOUT)
-            except asyncio.TimeoutError:
+                await asyncio.wait_for(
+                    self.pending_confirmations[connection.handle], GATT_REQUEST_TIMEOUT
+                )
+            except asyncio.TimeoutError as error:
                 logger.warning(color('!!! GATT Indicate timeout', 'red'))
-                raise TimeoutError(f'GATT timeout for {indication.name}')
+                raise TimeoutError(f'GATT timeout for {indication.name}') from error
             finally:
                 self.pending_confirmations[connection.handle] = None
 
-    async def indicate_subscribers(self, attribute):
+    async def notify_or_indicate_subscribers(
+        self, indicate, attribute, value=None, force=False
+    ):
         # Get all the connections for which there's at least one subscription
         connections = [
-            connection for connection in [
+            connection
+            for connection in [
                 self.device.lookup_connection(connection_handle)
                 for (connection_handle, subscribers) in self.subscribers.items()
-                if subscribers.get(attribute.handle)
+                if force or subscribers.get(attribute.handle)
             ]
             if connection is not None
         ]
 
-        # Indicate for each connection
+        # Indicate or notify for each connection
         if connections:
-            await asyncio.wait([
-                self.indicate_subscriber(connection, attribute)
-                for connection in connections
-            ])
+            coroutine = self.indicate_subscriber if indicate else self.notify_subscriber
+            await asyncio.wait(
+                [
+                    asyncio.create_task(coroutine(connection, attribute, value, force))
+                    for connection in connections
+                ]
+            )
+
+    async def notify_subscribers(self, attribute, value=None, force=False):
+        return await self.notify_or_indicate_subscribers(False, attribute, value, force)
+
+    async def indicate_subscribers(self, attribute, value=None, force=False):
+        return await self.notify_or_indicate_subscribers(True, attribute, value, force)
 
     def on_disconnection(self, connection):
-        if connection.handle in self.mtus:
-            del self.mtus[connection.handle]
         if connection.handle in self.subscribers:
             del self.subscribers[connection.handle]
         if connection.handle in self.indication_semaphores:
@@ -302,17 +464,17 @@ class Server(EventEmitter):
             except ATT_Error as error:
                 logger.debug(f'normal exception returned by handler: {error}')
                 response = ATT_Error_Response(
-                    request_opcode_in_error   = att_pdu.op_code,
-                    attribute_handle_in_error = error.att_handle,
-                    error_code                = error.error_code
+                    request_opcode_in_error=att_pdu.op_code,
+                    attribute_handle_in_error=error.att_handle,
+                    error_code=error.error_code,
                 )
                 self.send_response(connection, response)
             except Exception as error:
                 logger.warning(f'{color("!!! Exception in handler:", "red")} {error}')
                 response = ATT_Error_Response(
-                    request_opcode_in_error   = att_pdu.op_code,
-                    attribute_handle_in_error = 0x0000,
-                    error_code                = ATT_UNLIKELY_ERROR_ERROR
+                    request_opcode_in_error=att_pdu.op_code,
+                    attribute_handle_in_error=0x0000,
+                    error_code=ATT_UNLIKELY_ERROR_ERROR,
                 )
                 self.send_response(connection, response)
                 raise error
@@ -323,10 +485,13 @@ class Server(EventEmitter):
                 self.on_att_request(connection, att_pdu)
             else:
                 # Just ignore
-                logger.warning(f'{color("--- Ignoring GATT Request from [0x{connection.handle:04X}]:", "red")}  {att_pdu}')
-
-    def get_mtu(self, connection):
-        return self.mtus.get(connection.handle, ATT_DEFAULT_MTU)
+                logger.warning(
+                    color(
+                        f'--- Ignoring GATT Request from [0x{connection.handle:04X}]: ',
+                        'red',
+                    )
+                    + str(att_pdu)
+                )
 
     #######################################################
     # ATT handlers
@@ -335,11 +500,16 @@ class Server(EventEmitter):
         '''
         Handler for requests without a more specific handler
         '''
-        logger.warning(f'{color(f"--- Unsupported ATT Request from [0x{connection.handle:04X}]:", "red")} {pdu}')
+        logger.warning(
+            color(
+                f'--- Unsupported ATT Request from [0x{connection.handle:04X}]: ', 'red'
+            )
+            + str(pdu)
+        )
         response = ATT_Error_Response(
-            request_opcode_in_error   = pdu.op_code,
-            attribute_handle_in_error = 0x0000,
-            error_code                = ATT_REQUEST_NOT_SUPPORTED_ERROR
+            request_opcode_in_error=pdu.op_code,
+            attribute_handle_in_error=0x0000,
+            error_code=ATT_REQUEST_NOT_SUPPORTED_ERROR,
         )
         self.send_response(connection, response)
 
@@ -347,12 +517,18 @@ class Server(EventEmitter):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.2.1 Exchange MTU Request
         '''
-        mtu = max(ATT_DEFAULT_MTU, min(self.max_mtu, request.client_rx_mtu))
-        self.mtus[connection.handle] = mtu
-        self.send_response(connection, ATT_Exchange_MTU_Response(server_rx_mtu = mtu))
+        self.send_response(
+            connection, ATT_Exchange_MTU_Response(server_rx_mtu=self.max_mtu)
+        )
 
-        # Notify the device
-        self.device.on_connection_att_mtu_update(connection.handle, mtu)
+        # Compute the final MTU
+        if request.client_rx_mtu >= ATT_DEFAULT_MTU:
+            mtu = min(self.max_mtu, request.client_rx_mtu)
+
+            # Notify the device
+            self.device.on_connection_att_mtu_update(connection.handle, mtu)
+        else:
+            logger.warning('invalid client_rx_mtu received, MTU not changed')
 
     def on_att_find_information_request(self, connection, request):
         '''
@@ -360,25 +536,30 @@ class Server(EventEmitter):
         '''
 
         # Check the request parameters
-        if request.starting_handle == 0 or request.starting_handle > request.ending_handle:
-            self.send_response(connection, ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_INVALID_HANDLE_ERROR
-            ))
+        if (
+            request.starting_handle == 0
+            or request.starting_handle > request.ending_handle
+        ):
+            self.send_response(
+                connection,
+                ATT_Error_Response(
+                    request_opcode_in_error=request.op_code,
+                    attribute_handle_in_error=request.starting_handle,
+                    error_code=ATT_INVALID_HANDLE_ERROR,
+                ),
+            )
             return
 
         # Build list of returned attributes
-        pdu_space_available = self.get_mtu(connection) - 2
+        pdu_space_available = connection.att_mtu - 2
         attributes = []
         uuid_size = 0
         for attribute in (
-            attribute for attribute in self.attributes if
-            attribute.handle >= request.starting_handle and
-            attribute.handle <= request.ending_handle
+            attribute
+            for attribute in self.attributes
+            if attribute.handle >= request.starting_handle
+            and attribute.handle <= request.ending_handle
         ):
-            # TODO: check permissions
-
             this_uuid_size = len(attribute.type.to_pdu_bytes())
 
             if attributes:
@@ -402,14 +583,14 @@ class Server(EventEmitter):
                 for attribute in attributes
             ]
             response = ATT_Find_Information_Response(
-                format           = 1 if len(attributes[0].type.to_pdu_bytes()) == 2 else 2,
-                information_data = b''.join(information_data_list)
+                format=1 if len(attributes[0].type.to_pdu_bytes()) == 2 else 2,
+                information_data=b''.join(information_data_list),
             )
         else:
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_ATTRIBUTE_NOT_FOUND_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.starting_handle,
+                error_code=ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
         self.send_response(connection, response)
@@ -420,15 +601,16 @@ class Server(EventEmitter):
         '''
 
         # Build list of returned attributes
-        pdu_space_available = self.get_mtu(connection) - 2
+        pdu_space_available = connection.att_mtu - 2
         attributes = []
         for attribute in (
-            attribute for attribute in self.attributes if
-            attribute.handle                 >= request.starting_handle and
-            attribute.handle                 <= request.ending_handle   and
-            attribute.type                   == request.attribute_type  and
-            attribute.read_value(connection) == request.attribute_value and
-            pdu_space_available >= 4
+            attribute
+            for attribute in self.attributes
+            if attribute.handle >= request.starting_handle
+            and attribute.handle <= request.ending_handle
+            and attribute.type == request.attribute_type
+            and attribute.read_value(connection) == request.attribute_value
+            and pdu_space_available >= 4
         ):
             # TODO: check permissions
 
@@ -440,25 +622,27 @@ class Server(EventEmitter):
         if attributes:
             handles_information_list = []
             for attribute in attributes:
-                if attribute.type in {
+                if attribute.type in (
                     GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
                     GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
-                    GATT_CHARACTERISTIC_ATTRIBUTE_TYPE
-                }:
+                    GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
+                ):
                     # Part of a group
                     group_end_handle = attribute.end_group_handle
                 else:
                     # Not part of a group
                     group_end_handle = attribute.handle
-                handles_information_list.append(struct.pack('<HH', attribute.handle, group_end_handle))
+                handles_information_list.append(
+                    struct.pack('<HH', attribute.handle, group_end_handle)
+                )
             response = ATT_Find_By_Type_Value_Response(
-                handles_information_list = b''.join(handles_information_list)
+                handles_information_list=b''.join(handles_information_list)
             )
         else:
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_ATTRIBUTE_NOT_FOUND_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.starting_handle,
+                error_code=ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
         self.send_response(connection, response)
@@ -468,21 +652,39 @@ class Server(EventEmitter):
         See Bluetooth spec Vol 3, Part F - 3.4.4.1 Read By Type Request
         '''
 
-        mtu = self.get_mtu(connection)
-        pdu_space_available = mtu - 2
+        pdu_space_available = connection.att_mtu - 2
+
+        response = ATT_Error_Response(
+            request_opcode_in_error=request.op_code,
+            attribute_handle_in_error=request.starting_handle,
+            error_code=ATT_ATTRIBUTE_NOT_FOUND_ERROR,
+        )
+
         attributes = []
         for attribute in (
-            attribute for attribute in self.attributes if
-            attribute.type   == request.attribute_type  and
-            attribute.handle >= request.starting_handle and
-            attribute.handle <= request.ending_handle   and
-            pdu_space_available
+            attribute
+            for attribute in self.attributes
+            if attribute.type == request.attribute_type
+            and attribute.handle >= request.starting_handle
+            and attribute.handle <= request.ending_handle
+            and pdu_space_available
         ):
-            # TODO: check permissions
+
+            try:
+                attribute_value = attribute.read_value(connection)
+            except ATT_Error as error:
+                # If the first attribute is unreadable, return an error
+                # Otherwise return attributes up to this point
+                if not attributes:
+                    response = ATT_Error_Response(
+                        request_opcode_in_error=request.op_code,
+                        attribute_handle_in_error=attribute.handle,
+                        error_code=error.error_code,
+                    )
+                break
 
             # Check the attribute value size
-            attribute_value = attribute.read_value(connection)
-            max_attribute_size = min(mtu - 4, 253)
+            max_attribute_size = min(connection.att_mtu - 4, 253)
             if len(attribute_value) > max_attribute_size:
                 # We need to truncate
                 attribute_value = attribute_value[:max_attribute_size]
@@ -500,17 +702,14 @@ class Server(EventEmitter):
             pdu_space_available -= entry_size
 
         if attributes:
-            attribute_data_list = [struct.pack('<H', handle) + value for handle, value in attributes]
+            attribute_data_list = [
+                struct.pack('<H', handle) + value for handle, value in attributes
+            ]
             response = ATT_Read_By_Type_Response(
-                length              = entry_size,
-                attribute_data_list = b''.join(attribute_data_list)
+                length=entry_size, attribute_data_list=b''.join(attribute_data_list)
             )
         else:
-            response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_ATTRIBUTE_NOT_FOUND_ERROR
-            )
+            logging.debug(f"not found {request}")
 
         self.send_response(connection, response)
 
@@ -520,17 +719,22 @@ class Server(EventEmitter):
         '''
 
         if attribute := self.get_attribute(request.attribute_handle):
-            # TODO: check permissions
-            value = attribute.read_value(connection)
-            value_size = min(self.get_mtu(connection) - 1, len(value))
-            response = ATT_Read_Response(
-                attribute_value = value[:value_size]
-            )
+            try:
+                value = attribute.read_value(connection)
+            except ATT_Error as error:
+                response = ATT_Error_Response(
+                    request_opcode_in_error=request.op_code,
+                    attribute_handle_in_error=request.attribute_handle,
+                    error_code=error.error_code,
+                )
+            else:
+                value_size = min(connection.att_mtu - 1, len(value))
+                response = ATT_Read_Response(attribute_value=value[:value_size])
         else:
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.attribute_handle,
-                error_code                = ATT_INVALID_HANDLE_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.attribute_handle,
+                error_code=ATT_INVALID_HANDLE_ERROR,
             )
         self.send_response(connection, response)
 
@@ -540,31 +744,41 @@ class Server(EventEmitter):
         '''
 
         if attribute := self.get_attribute(request.attribute_handle):
-            # TODO: check permissions
-            mtu = self.get_mtu(connection)
-            value = attribute.read_value(connection)
-            if request.value_offset > len(value):
+            try:
+                value = attribute.read_value(connection)
+            except ATT_Error as error:
                 response = ATT_Error_Response(
-                    request_opcode_in_error   = request.op_code,
-                    attribute_handle_in_error = request.attribute_handle,
-                    error_code                = ATT_INVALID_OFFSET_ERROR
-                )
-            elif len(value) <= mtu - 1:
-                response = ATT_Error_Response(
-                    request_opcode_in_error   = request.op_code,
-                    attribute_handle_in_error = request.attribute_handle,
-                    error_code                = ATT_ATTRIBUTE_NOT_LONG_ERROR
+                    request_opcode_in_error=request.op_code,
+                    attribute_handle_in_error=request.attribute_handle,
+                    error_code=error.error_code,
                 )
             else:
-                part_size = min(mtu - 1, len(value) - request.value_offset)
-                response = ATT_Read_Blob_Response(
-                    part_attribute_value = value[request.value_offset:request.value_offset + part_size]
-                )
+                if request.value_offset > len(value):
+                    response = ATT_Error_Response(
+                        request_opcode_in_error=request.op_code,
+                        attribute_handle_in_error=request.attribute_handle,
+                        error_code=ATT_INVALID_OFFSET_ERROR,
+                    )
+                elif len(value) <= connection.att_mtu - 1:
+                    response = ATT_Error_Response(
+                        request_opcode_in_error=request.op_code,
+                        attribute_handle_in_error=request.attribute_handle,
+                        error_code=ATT_ATTRIBUTE_NOT_LONG_ERROR,
+                    )
+                else:
+                    part_size = min(
+                        connection.att_mtu - 1, len(value) - request.value_offset
+                    )
+                    response = ATT_Read_Blob_Response(
+                        part_attribute_value=value[
+                            request.value_offset : request.value_offset + part_size
+                        ]
+                    )
         else:
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.attribute_handle,
-                error_code                = ATT_INVALID_HANDLE_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.attribute_handle,
+                error_code=ATT_INVALID_HANDLE_ERROR,
             )
         self.send_response(connection, response)
 
@@ -572,32 +786,33 @@ class Server(EventEmitter):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.4.9 Read by Group Type Request
         '''
-        if request.attribute_group_type not in {
+        if request.attribute_group_type not in (
             GATT_PRIMARY_SERVICE_ATTRIBUTE_TYPE,
             GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
-            GATT_INCLUDE_ATTRIBUTE_TYPE
-        }:
+        ):
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_UNSUPPORTED_GROUP_TYPE_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.starting_handle,
+                error_code=ATT_UNSUPPORTED_GROUP_TYPE_ERROR,
             )
             self.send_response(connection, response)
             return
 
-        mtu = self.get_mtu(connection)
-        pdu_space_available = mtu - 2
+        pdu_space_available = connection.att_mtu - 2
         attributes = []
         for attribute in (
-            attribute for attribute in self.attributes if
-            attribute.type   == request.attribute_group_type and
-            attribute.handle >= request.starting_handle      and
-            attribute.handle <= request.ending_handle        and
-            pdu_space_available
+            attribute
+            for attribute in self.attributes
+            if attribute.type == request.attribute_group_type
+            and attribute.handle >= request.starting_handle
+            and attribute.handle <= request.ending_handle
+            and pdu_space_available
         ):
-            # Check the attribute value size
+            # No need to catch permission errors here, since these attributes
+            # must all be world-readable
             attribute_value = attribute.read_value(connection)
-            max_attribute_size = min(mtu - 6, 251)
+            # Check the attribute value size
+            max_attribute_size = min(connection.att_mtu - 6, 251)
             if len(attribute_value) > max_attribute_size:
                 # We need to truncate
                 attribute_value = attribute_value[:max_attribute_size]
@@ -611,7 +826,9 @@ class Server(EventEmitter):
                 break
 
             # Add the attribute to the list
-            attributes.append((attribute.handle, attribute.end_group_handle, attribute_value))
+            attributes.append(
+                (attribute.handle, attribute.end_group_handle, attribute_value)
+            )
             pdu_space_available -= entry_size
 
         if attributes:
@@ -620,14 +837,14 @@ class Server(EventEmitter):
                 for handle, end_group_handle, value in attributes
             ]
             response = ATT_Read_By_Group_Type_Response(
-                length              = len(attribute_data_list[0]),
-                attribute_data_list = b''.join(attribute_data_list)
+                length=len(attribute_data_list[0]),
+                attribute_data_list=b''.join(attribute_data_list),
             )
         else:
             response = ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.starting_handle,
-                error_code                = ATT_ATTRIBUTE_NOT_FOUND_ERROR
+                request_opcode_in_error=request.op_code,
+                attribute_handle_in_error=request.starting_handle,
+                error_code=ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
         self.send_response(connection, response)
@@ -640,22 +857,28 @@ class Server(EventEmitter):
         # Check  that the attribute exists
         attribute = self.get_attribute(request.attribute_handle)
         if attribute is None:
-            self.send_response(connection, ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.attribute_handle,
-                error_code                = ATT_INVALID_HANDLE_ERROR
-            ))
+            self.send_response(
+                connection,
+                ATT_Error_Response(
+                    request_opcode_in_error=request.op_code,
+                    attribute_handle_in_error=request.attribute_handle,
+                    error_code=ATT_INVALID_HANDLE_ERROR,
+                ),
+            )
             return
 
         # TODO: check permissions
 
         # Check the request parameters
         if len(request.attribute_value) > GATT_MAX_ATTRIBUTE_VALUE_SIZE:
-            self.send_response(connection, ATT_Error_Response(
-                request_opcode_in_error   = request.op_code,
-                attribute_handle_in_error = request.attribute_handle,
-                error_code                = ATT_INVALID_ATTRIBUTE_LENGTH_ERROR
-            ))
+            self.send_response(
+                connection,
+                ATT_Error_Response(
+                    request_opcode_in_error=request.op_code,
+                    attribute_handle_in_error=request.attribute_handle,
+                    error_code=ATT_INVALID_ATTRIBUTE_LENGTH_ERROR,
+                ),
+            )
             return
 
         # Accept the value
@@ -686,13 +909,15 @@ class Server(EventEmitter):
         except Exception as error:
             logger.warning(f'!!! ignoring exception: {error}')
 
-    def on_att_handle_value_confirmation(self, connection, confirmation):
+    def on_att_handle_value_confirmation(self, connection, _confirmation):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.7.3 Handle Value Confirmation
         '''
         if self.pending_confirmations[connection.handle] is None:
             # Not expected!
-            logger.warning('!!! unexpected confirmation, there is no pending indication')
+            logger.warning(
+                '!!! unexpected confirmation, there is no pending indication'
+            )
             return
 
         self.pending_confirmations[connection.handle].set_result(None)

bumble/helpers.py

@@ -16,10 +16,11 @@
 # Imports
 # -----------------------------------------------------------------------------
 import logging
-from colors import color
 
+from .colors import color
+from .att import ATT_CID, ATT_PDU
+from .smp import SMP_CID, SMP_Command
 from .core import name_or_number
-from .gatt import ATT_PDU, ATT_CID
 from .l2cap import (
     L2CAP_PDU,
     L2CAP_CONNECTION_REQUEST,
@@ -27,20 +28,17 @@ from .l2cap import (
     L2CAP_SIGNALING_CID,
     L2CAP_LE_SIGNALING_CID,
     L2CAP_Control_Frame,
-    L2CAP_Connection_Response
+    L2CAP_Connection_Response,
 )
 from .hci import (
     HCI_EVENT_PACKET,
     HCI_ACL_DATA_PACKET,
     HCI_DISCONNECTION_COMPLETE_EVENT,
-    HCI_AclDataPacketAssembler
+    HCI_AclDataPacketAssembler,
 )
 from .rfcomm import RFCOMM_Frame, RFCOMM_PSM
 from .sdp import SDP_PDU, SDP_PSM
-from .avdtp import (
-    MessageAssembler as AVDTP_MessageAssembler,
-    AVDTP_PSM
-)
+from .avdtp import MessageAssembler as AVDTP_MessageAssembler, AVDTP_PSM
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -51,8 +49,8 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 PSM_NAMES = {
     RFCOMM_PSM: 'RFCOMM',
-    SDP_PSM:    'SDP',
-    AVDTP_PSM:  'AVDTP'
+    SDP_PSM: 'SDP',
+    AVDTP_PSM: 'AVDTP'
     # TODO: add more PSM values
 }
 
@@ -61,19 +59,23 @@ PSM_NAMES = {
 class PacketTracer:
     class AclStream:
         def __init__(self, analyzer):
-            self.analyzer         = analyzer
+            self.analyzer = analyzer
             self.packet_assembler = HCI_AclDataPacketAssembler(self.on_acl_pdu)
-            self.avdtp_assemblers = {}    # AVDTP assemblers, by source_cid
-            self.psms             = {}    # PSM, by source_cid
-            self.peer             = None  # ACL stream in the other direction
+            self.avdtp_assemblers = {}  # AVDTP assemblers, by source_cid
+            self.psms = {}  # PSM, by source_cid
+            self.peer = None  # ACL stream in the other direction
 
+        # pylint: disable=too-many-nested-blocks
         def on_acl_pdu(self, pdu):
             l2cap_pdu = L2CAP_PDU.from_bytes(pdu)
 
             if l2cap_pdu.cid == ATT_CID:
                 att_pdu = ATT_PDU.from_bytes(l2cap_pdu.payload)
                 self.analyzer.emit(att_pdu)
-            elif l2cap_pdu.cid == L2CAP_SIGNALING_CID or l2cap_pdu.cid == L2CAP_LE_SIGNALING_CID:
+            elif l2cap_pdu.cid == SMP_CID:
+                smp_command = SMP_Command.from_bytes(l2cap_pdu.payload)
+                self.analyzer.emit(smp_command)
+            elif l2cap_pdu.cid in (L2CAP_SIGNALING_CID, L2CAP_LE_SIGNALING_CID):
                 control_frame = L2CAP_Control_Frame.from_bytes(l2cap_pdu.payload)
                 self.analyzer.emit(control_frame)
 
@@ -81,16 +83,26 @@ class PacketTracer:
                 if control_frame.code == L2CAP_CONNECTION_REQUEST:
                     self.psms[control_frame.source_cid] = control_frame.psm
                 elif control_frame.code == L2CAP_CONNECTION_RESPONSE:
-                    if control_frame.result == L2CAP_Connection_Response.CONNECTION_SUCCESSFUL:
+                    if (
+                        control_frame.result
+                        == L2CAP_Connection_Response.CONNECTION_SUCCESSFUL
+                    ):
                         if self.peer:
                             if psm := self.peer.psms.get(control_frame.source_cid):
                                 # Found a pending connection
                                 self.psms[control_frame.destination_cid] = psm
 
-                                # For AVDTP connections, create a packet assembler for each direction
+                                # For AVDTP connections, create a packet assembler for
+                                # each direction
                                 if psm == AVDTP_PSM:
-                                    self.avdtp_assemblers[control_frame.source_cid] = AVDTP_MessageAssembler(self.on_avdtp_message)
-                                    self.peer.avdtp_assemblers[control_frame.destination_cid] = AVDTP_MessageAssembler(self.peer.on_avdtp_message)
+                                    self.avdtp_assemblers[
+                                        control_frame.source_cid
+                                    ] = AVDTP_MessageAssembler(self.on_avdtp_message)
+                                    self.peer.avdtp_assemblers[
+                                        control_frame.destination_cid
+                                    ] = AVDTP_MessageAssembler(
+                                        self.peer.on_avdtp_message
+                                    )
 
             else:
                 # Try to find the PSM associated with this PDU
@@ -102,31 +114,42 @@ class PacketTracer:
                         rfcomm_frame = RFCOMM_Frame.from_bytes(l2cap_pdu.payload)
                         self.analyzer.emit(rfcomm_frame)
                     elif psm == AVDTP_PSM:
-                        self.analyzer.emit(f'{color("L2CAP", "green")} [CID={l2cap_pdu.cid}, PSM=AVDTP]: {l2cap_pdu.payload.hex()}')
+                        self.analyzer.emit(
+                            f'{color("L2CAP", "green")} [CID={l2cap_pdu.cid}, '
+                            f'PSM=AVDTP]: {l2cap_pdu.payload.hex()}'
+                        )
                         assembler = self.avdtp_assemblers.get(l2cap_pdu.cid)
                         if assembler:
                             assembler.on_pdu(l2cap_pdu.payload)
                     else:
                         psm_string = name_or_number(PSM_NAMES, psm)
-                        self.analyzer.emit(f'{color("L2CAP", "green")} [CID={l2cap_pdu.cid}, PSM={psm_string}]: {l2cap_pdu.payload.hex()}')
+                        self.analyzer.emit(
+                            f'{color("L2CAP", "green")} [CID={l2cap_pdu.cid}, '
+                            f'PSM={psm_string}]: {l2cap_pdu.payload.hex()}'
+                        )
                 else:
                     self.analyzer.emit(l2cap_pdu)
 
         def on_avdtp_message(self, transaction_label, message):
-            self.analyzer.emit(f'{color("AVDTP", "green")} [{transaction_label}] {message}')
+            self.analyzer.emit(
+                f'{color("AVDTP", "green")} [{transaction_label}] {message}'
+            )
 
         def feed_packet(self, packet):
             self.packet_assembler.feed_packet(packet)
 
     class Analyzer:
         def __init__(self, label, emit_message):
-            self.label        = label
+            self.label = label
             self.emit_message = emit_message
-            self.acl_streams  = {}    # ACL streams, by connection handle
-            self.peer         = None  # Analyzer in the other direction
+            self.acl_streams = {}  # ACL streams, by connection handle
+            self.peer = None  # Analyzer in the other direction
 
         def start_acl_stream(self, connection_handle):
-            logger.info(f'[{self.label}] +++ Creating ACL stream for connection 0x{connection_handle:04X}')
+            logger.info(
+                f'[{self.label}] +++ Creating ACL stream for connection '
+                f'0x{connection_handle:04X}'
+            )
             stream = PacketTracer.AclStream(self)
             self.acl_streams[connection_handle] = stream
 
@@ -139,7 +162,10 @@ class PacketTracer:
 
         def end_acl_stream(self, connection_handle):
             if connection_handle in self.acl_streams:
-                logger.info(f'[{self.label}] --- Removing ACL stream for connection 0x{connection_handle:04X}')
+                logger.info(
+                    f'[{self.label}] --- Removing ACL stream for connection '
+                    f'0x{connection_handle:04X}'
+                )
                 del self.acl_streams[connection_handle]
 
                 # Let the other forwarder know so it can cleanup its stream as well
@@ -171,9 +197,13 @@ class PacketTracer:
         self,
         host_to_controller_label=color('HOST->CONTROLLER', 'blue'),
         controller_to_host_label=color('CONTROLLER->HOST', 'cyan'),
-        emit_message=logger.info
+        emit_message=logger.info,
     ):
-        self.host_to_controller_analyzer = PacketTracer.Analyzer(host_to_controller_label, emit_message)
-        self.controller_to_host_analyzer = PacketTracer.Analyzer(controller_to_host_label, emit_message)
+        self.host_to_controller_analyzer = PacketTracer.Analyzer(
+            host_to_controller_label, emit_message
+        )
+        self.controller_to_host_analyzer = PacketTracer.Analyzer(
+            controller_to_host_label, emit_message
+        )
         self.host_to_controller_analyzer.peer = self.controller_to_host_analyzer
         self.controller_to_host_analyzer.peer = self.host_to_controller_analyzer

bumble/hfp.py

@@ -18,7 +18,8 @@
 import logging
 import asyncio
 import collections
-from colors import color
+
+from .colors import color
 
 
 # -----------------------------------------------------------------------------
@@ -34,16 +35,16 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 class HfpProtocol:
     def __init__(self, dlc):
-        self.dlc             = dlc
-        self.buffer          = ''
-        self.lines           = collections.deque()
+        self.dlc = dlc
+        self.buffer = ''
+        self.lines = collections.deque()
         self.lines_available = asyncio.Event()
 
         dlc.sink = self.feed
 
     def feed(self, data):
         # Convert the data to a string if needed
-        if type(data) == bytes:
+        if isinstance(data, bytes):
             data = data.decode('utf-8')
 
         logger.debug(f'<<< Data received: {data}')
@@ -52,7 +53,7 @@ class HfpProtocol:
         self.buffer += data
         while (separator := self.buffer.find('\r')) >= 0:
             line = self.buffer[:separator].strip()
-            self.buffer = self.buffer[separator + 1:]
+            self.buffer = self.buffer[separator + 1 :]
             if len(line) > 0:
                 self.on_line(line)
 
@@ -79,16 +80,16 @@ class HfpProtocol:
     async def initialize_service(self):
         # Perform Service Level Connection Initialization
         self.send_command_line('AT+BRSF=2072')  # Retrieve Supported Features
-        line = await(self.next_line())
-        line = await(self.next_line())
+        await (self.next_line())
+        await (self.next_line())
 
         self.send_command_line('AT+CIND=?')
-        line = await(self.next_line())
-        line = await(self.next_line())
+        await (self.next_line())
+        await (self.next_line())
 
         self.send_command_line('AT+CIND?')
-        line = await(self.next_line())
-        line = await(self.next_line())
+        await (self.next_line())
+        await (self.next_line())
 
         self.send_command_line('AT+CMER=3,0,0,1')
-        line = await(self.next_line())
+        await (self.next_line())

bumble/host.py

@@ -16,16 +16,62 @@
 # Imports
 # -----------------------------------------------------------------------------
 import asyncio
+import collections
 import logging
-from pyee import EventEmitter
-from colors import color
+import struct
+
+from bumble.colors import color
+from bumble.l2cap import L2CAP_PDU
+from bumble.snoop import Snooper
+
+from typing import Optional
+
+from .hci import (
+    Address,
+    HCI_ACL_DATA_PACKET,
+    HCI_COMMAND_COMPLETE_EVENT,
+    HCI_COMMAND_PACKET,
+    HCI_EVENT_PACKET,
+    HCI_LE_READ_BUFFER_SIZE_COMMAND,
+    HCI_LE_READ_LOCAL_SUPPORTED_FEATURES_COMMAND,
+    HCI_LE_READ_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND,
+    HCI_LE_WRITE_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND,
+    HCI_READ_BUFFER_SIZE_COMMAND,
+    HCI_READ_LOCAL_VERSION_INFORMATION_COMMAND,
+    HCI_RESET_COMMAND,
+    HCI_SUCCESS,
+    HCI_SUPPORTED_COMMANDS_FLAGS,
+    HCI_VERSION_BLUETOOTH_CORE_4_0,
+    HCI_AclDataPacket,
+    HCI_AclDataPacketAssembler,
+    HCI_Constant,
+    HCI_Error,
+    HCI_LE_Long_Term_Key_Request_Negative_Reply_Command,
+    HCI_LE_Long_Term_Key_Request_Reply_Command,
+    HCI_LE_Read_Buffer_Size_Command,
+    HCI_LE_Read_Local_Supported_Features_Command,
+    HCI_LE_Read_Suggested_Default_Data_Length_Command,
+    HCI_LE_Remote_Connection_Parameter_Request_Reply_Command,
+    HCI_LE_Set_Event_Mask_Command,
+    HCI_LE_Write_Suggested_Default_Data_Length_Command,
+    HCI_Link_Key_Request_Negative_Reply_Command,
+    HCI_Link_Key_Request_Reply_Command,
+    HCI_Packet,
+    HCI_Read_Buffer_Size_Command,
+    HCI_Read_Local_Supported_Commands_Command,
+    HCI_Read_Local_Version_Information_Command,
+    HCI_Reset_Command,
+    HCI_Set_Event_Mask_Command,
+)
+from .core import (
+    BT_BR_EDR_TRANSPORT,
+    BT_CENTRAL_ROLE,
+    BT_LE_TRANSPORT,
+    ConnectionPHY,
+    ConnectionParameters,
+)
+from .utils import AbortableEventEmitter
 
-from .hci import *
-from .l2cap import *
-from .att import *
-from .gatt import *
-from .smp import *
-from .core import ConnectionParameters
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -36,58 +82,61 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+
 HOST_DEFAULT_HC_LE_ACL_DATA_PACKET_LENGTH = 27
 HOST_HC_TOTAL_NUM_LE_ACL_DATA_PACKETS     = 1
 HOST_DEFAULT_HC_ACL_DATA_PACKET_LENGTH    = 27
 HOST_HC_TOTAL_NUM_ACL_DATA_PACKETS        = 1
 
+# fmt: on
+
 
 # -----------------------------------------------------------------------------
 class Connection:
-    def __init__(self, host, handle, role, peer_address):
-        self.host                  = host
-        self.handle                = handle
-        self.role                  = role
-        self.peer_address          = peer_address
-        self.assembler             = HCI_AclDataPacketAssembler(self.on_acl_pdu)
+    def __init__(self, host, handle, role, peer_address, transport):
+        self.host = host
+        self.handle = handle
+        self.role = role
+        self.peer_address = peer_address
+        self.assembler = HCI_AclDataPacketAssembler(self.on_acl_pdu)
+        self.transport = transport
 
     def on_hci_acl_data_packet(self, packet):
         self.assembler.feed_packet(packet)
 
     def on_acl_pdu(self, pdu):
         l2cap_pdu = L2CAP_PDU.from_bytes(pdu)
-
-        if l2cap_pdu.cid == ATT_CID:
-            self.host.on_gatt_pdu(self, l2cap_pdu.payload)
-        elif l2cap_pdu.cid == SMP_CID:
-            self.host.on_smp_pdu(self, l2cap_pdu.payload)
-        else:
-            self.host.on_l2cap_pdu(self, l2cap_pdu.cid, l2cap_pdu.payload)
+        self.host.on_l2cap_pdu(self, l2cap_pdu.cid, l2cap_pdu.payload)
 
 
 # -----------------------------------------------------------------------------
-class Host(EventEmitter):
-    def __init__(self, controller_source = None, controller_sink = None):
+class Host(AbortableEventEmitter):
+    def __init__(self, controller_source=None, controller_sink=None):
         super().__init__()
 
-        self.hci_sink                         = None
-        self.ready                            = False  # True when we can accept incoming packets
-        self.connections                      = {}     # Connections, by connection handle
-        self.pending_command                  = None
-        self.pending_response                 = None
-        self.hc_le_acl_data_packet_length     = HOST_DEFAULT_HC_LE_ACL_DATA_PACKET_LENGTH
+        self.hci_sink = None
+        self.ready = False  # True when we can accept incoming packets
+        self.reset_done = False
+        self.connections = {}  # Connections, by connection handle
+        self.pending_command = None
+        self.pending_response = None
+        self.hc_le_acl_data_packet_length = HOST_DEFAULT_HC_LE_ACL_DATA_PACKET_LENGTH
         self.hc_total_num_le_acl_data_packets = HOST_HC_TOTAL_NUM_LE_ACL_DATA_PACKETS
-        self.hc_acl_data_packet_length        = HOST_DEFAULT_HC_ACL_DATA_PACKET_LENGTH
-        self.hc_total_num_acl_data_packets    = HOST_HC_TOTAL_NUM_ACL_DATA_PACKETS
-        self.acl_packet_queue                 = collections.deque()
-        self.acl_packets_in_flight            = 0
-        self.local_version                    = None
-        self.local_supported_commands         = bytes(64)
-        self.local_le_features                = 0
-        self.command_semaphore                = asyncio.Semaphore(1)
-        self.long_term_key_provider           = None
-        self.link_key_provider                = None
-        self.pairing_io_capability_provider   = None  # Classic only
+        self.hc_acl_data_packet_length = HOST_DEFAULT_HC_ACL_DATA_PACKET_LENGTH
+        self.hc_total_num_acl_data_packets = HOST_HC_TOTAL_NUM_ACL_DATA_PACKETS
+        self.acl_packet_queue = collections.deque()
+        self.acl_packets_in_flight = 0
+        self.local_version = None
+        self.local_supported_commands = bytes(64)
+        self.local_le_features = 0
+        self.suggested_max_tx_octets = 251  # Max allowed
+        self.suggested_max_tx_time = 2120  # Max allowed
+        self.command_semaphore = asyncio.Semaphore(1)
+        self.long_term_key_provider = None
+        self.link_key_provider = None
+        self.pairing_io_capability_provider = None  # Classic only
+        self.snooper = None
 
         # Connect to the source and sink if specified
         if controller_source:
@@ -95,55 +144,140 @@ class Host(EventEmitter):
         if controller_sink:
             self.set_packet_sink(controller_sink)
 
+    def find_connection_by_bd_addr(
+        self,
+        bd_addr: Address,
+        transport: Optional[int] = None,
+        check_address_type: bool = False,
+    ) -> Optional[Connection]:
+        for connection in self.connections.values():
+            if connection.peer_address.to_bytes() == bd_addr.to_bytes():
+                if (
+                    check_address_type
+                    and connection.peer_address.address_type != bd_addr.address_type
+                ):
+                    continue
+                if transport is None or connection.transport == transport:
+                    return connection
+
+        return None
+
+    async def flush(self) -> None:
+        # Make sure no command is pending
+        await self.command_semaphore.acquire()
+
+        # Flush current host state, then release command semaphore
+        self.emit('flush')
+        self.command_semaphore.release()
+
     async def reset(self):
-        await self.send_command(HCI_Reset_Command())
+        if self.ready:
+            self.ready = False
+            await self.flush()
+
+        await self.send_command(HCI_Reset_Command(), check_result=True)
         self.ready = True
 
-        await self.send_command(HCI_Set_Event_Mask_Command(event_mask = bytes.fromhex('FFFFFFFFFFFFFFFF')))
-        await self.send_command(HCI_LE_Set_Event_Mask_Command(le_event_mask = bytes.fromhex('FFFFF00000000000')))
-
-        response = await self.send_command(HCI_Read_Local_Supported_Commands_Command())
-        if response.return_parameters.status == HCI_SUCCESS:
-            self.local_supported_commands = response.return_parameters.supported_commands
-        else:
-            logger.warn(f'HCI_Read_Local_Supported_Commands_Command failed: {response.return_parameters.status}')
-
-        if self.supports_command(HCI_WRITE_LE_HOST_SUPPORT_COMMAND):
-            await self.send_command(HCI_Write_LE_Host_Support_Command(le_supported_host = 1, simultaneous_le_host = 0))
-
-        if self.supports_command(HCI_READ_LOCAL_VERSION_INFORMATION_COMMAND):
-            response = await self.send_command(HCI_Read_Local_Version_Information_Command())
-            if response.return_parameters.status == HCI_SUCCESS:
-                self.local_version = response.return_parameters
-            else:
-                logger.warn(f'HCI_Read_Local_Version_Information_Command failed: {response.return_parameters.status}')
-
-        if self.supports_command(HCI_LE_READ_BUFFER_SIZE_COMMAND):
-            response = await self.send_command(HCI_LE_Read_Buffer_Size_Command())
-            if response.return_parameters.status == HCI_SUCCESS:
-                self.hc_le_acl_data_packet_length = response.return_parameters.hc_le_acl_data_packet_length
-                self.hc_total_num_le_acl_data_packets = response.return_parameters.hc_total_num_le_acl_data_packets
-                logger.debug(f'HCI LE ACL flow control: hc_le_acl_data_packet_length={response.return_parameters.hc_le_acl_data_packet_length}, hc_total_num_le_acl_data_packets={response.return_parameters.hc_total_num_le_acl_data_packets}')
-            else:
-                logger.warn(f'HCI_LE_Read_Buffer_Size_Command failed: {response.return_parameters.status}')
-            if response.return_parameters.hc_le_acl_data_packet_length == 0 or response.return_parameters.hc_total_num_le_acl_data_packets == 0:
-                # Read the non-LE-specific values
-                response = await self.send_command(HCI_Read_Buffer_Size_Command())
-                if response.return_parameters.status == HCI_SUCCESS:
-                    self.hc_acl_data_packet_length        = response.return_parameters.hc_le_acl_data_packet_length
-                    self.hc_le_acl_data_packet_length     = self.hc_le_acl_data_packet_length or self.hc_acl_data_packet_length
-                    self.hc_total_num_acl_data_packets    = response.return_parameters.hc_total_num_le_acl_data_packets
-                    self.hc_total_num_le_acl_data_packets = self.hc_total_num_le_acl_data_packets or self.hc_total_num_acl_data_packets
-                    logger.debug(f'HCI LE ACL flow control: hc_le_acl_data_packet_length={self.hc_le_acl_data_packet_length}, hc_total_num_le_acl_data_packets={self.hc_total_num_le_acl_data_packets}')
-                else:
-                    logger.warn(f'HCI_Read_Buffer_Size_Command failed: {response.return_parameters.status}')
+        response = await self.send_command(
+            HCI_Read_Local_Supported_Commands_Command(), check_result=True
+        )
+        self.local_supported_commands = response.return_parameters.supported_commands
 
         if self.supports_command(HCI_LE_READ_LOCAL_SUPPORTED_FEATURES_COMMAND):
-            response = await self.send_command(HCI_LE_Read_Local_Supported_Features_Command())
-            if response.return_parameters.status == HCI_SUCCESS:
-                self.local_le_features = struct.unpack('<Q', response.return_parameters.le_features)[0]
-            else:
-                logger.warn(f'HCI_LE_Read_Supported_Features_Command failed: {response.return_parameters.status}')
+            response = await self.send_command(
+                HCI_LE_Read_Local_Supported_Features_Command(), check_result=True
+            )
+            self.local_le_features = struct.unpack(
+                '<Q', response.return_parameters.le_features
+            )[0]
+
+        if self.supports_command(HCI_READ_LOCAL_VERSION_INFORMATION_COMMAND):
+            response = await self.send_command(
+                HCI_Read_Local_Version_Information_Command(), check_result=True
+            )
+            self.local_version = response.return_parameters
+
+        await self.send_command(
+            HCI_Set_Event_Mask_Command(event_mask=bytes.fromhex('FFFFFFFFFFFFFF3F'))
+        )
+
+        if (
+            self.local_version is not None
+            and self.local_version.hci_version <= HCI_VERSION_BLUETOOTH_CORE_4_0
+        ):
+            # Some older controllers don't like event masks with bits they don't
+            # understand
+            le_event_mask = bytes.fromhex('1F00000000000000')
+        else:
+            le_event_mask = bytes.fromhex('FFFFF00000000000')
+
+        await self.send_command(
+            HCI_LE_Set_Event_Mask_Command(le_event_mask=le_event_mask)
+        )
+
+        if self.supports_command(HCI_READ_BUFFER_SIZE_COMMAND):
+            response = await self.send_command(
+                HCI_Read_Buffer_Size_Command(), check_result=True
+            )
+            self.hc_acl_data_packet_length = (
+                response.return_parameters.hc_acl_data_packet_length
+            )
+            self.hc_total_num_acl_data_packets = (
+                response.return_parameters.hc_total_num_acl_data_packets
+            )
+
+            logger.debug(
+                'HCI ACL flow control: '
+                f'hc_acl_data_packet_length={self.hc_acl_data_packet_length},'
+                f'hc_total_num_acl_data_packets={self.hc_total_num_acl_data_packets}'
+            )
+
+        if self.supports_command(HCI_LE_READ_BUFFER_SIZE_COMMAND):
+            response = await self.send_command(
+                HCI_LE_Read_Buffer_Size_Command(), check_result=True
+            )
+            self.hc_le_acl_data_packet_length = (
+                response.return_parameters.hc_le_acl_data_packet_length
+            )
+            self.hc_total_num_le_acl_data_packets = (
+                response.return_parameters.hc_total_num_le_acl_data_packets
+            )
+
+            logger.debug(
+                'HCI LE ACL flow control: '
+                f'hc_le_acl_data_packet_length={self.hc_le_acl_data_packet_length},'
+                'hc_total_num_le_acl_data_packets='
+                f'{self.hc_total_num_le_acl_data_packets}'
+            )
+
+            if (
+                response.return_parameters.hc_le_acl_data_packet_length == 0
+                or response.return_parameters.hc_total_num_le_acl_data_packets == 0
+            ):
+                # LE and Classic share the same values
+                self.hc_le_acl_data_packet_length = self.hc_acl_data_packet_length
+                self.hc_total_num_le_acl_data_packets = (
+                    self.hc_total_num_acl_data_packets
+                )
+
+        if self.supports_command(
+            HCI_LE_READ_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND
+        ) and self.supports_command(HCI_LE_WRITE_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND):
+            response = await self.send_command(
+                HCI_LE_Read_Suggested_Default_Data_Length_Command()
+            )
+            suggested_max_tx_octets = response.return_parameters.suggested_max_tx_octets
+            suggested_max_tx_time = response.return_parameters.suggested_max_tx_time
+            if (
+                suggested_max_tx_octets != self.suggested_max_tx_octets
+                or suggested_max_tx_time != self.suggested_max_tx_time
+            ):
+                await self.send_command(
+                    HCI_LE_Write_Suggested_Default_Data_Length_Command(
+                        suggested_max_tx_octets=self.suggested_max_tx_octets,
+                        suggested_max_tx_time=self.suggested_max_tx_time,
+                    )
+                )
 
         self.reset_done = True
 
@@ -161,15 +295,18 @@ class Host(EventEmitter):
         self.hci_sink = sink
 
     def send_hci_packet(self, packet):
+        if self.snooper:
+            self.snooper.snoop(bytes(packet), Snooper.Direction.HOST_TO_CONTROLLER)
+
         self.hci_sink.on_packet(packet.to_bytes())
 
-    async def send_command(self, command):
+    async def send_command(self, command, check_result=False):
         logger.debug(f'{color("### HOST -> CONTROLLER", "blue")}: {command}')
 
         # Wait until we can send (only one pending command at a time)
         async with self.command_semaphore:
-            assert(self.pending_command is None)
-            assert(self.pending_response is None)
+            assert self.pending_command is None
+            assert self.pending_response is None
 
             # Create a future value to hold the eventual response
             self.pending_response = asyncio.get_running_loop().create_future()
@@ -178,11 +315,29 @@ class Host(EventEmitter):
             try:
                 self.send_hci_packet(command)
                 response = await self.pending_response
-                # TODO: check error values
+
+                # Check the return parameters if required
+                if check_result:
+                    if isinstance(response.return_parameters, int):
+                        status = response.return_parameters
+                    elif isinstance(response.return_parameters, bytes):
+                        # return parameters first field is a one byte status code
+                        status = response.return_parameters[0]
+                    else:
+                        status = response.return_parameters.status
+
+                    if status != HCI_SUCCESS:
+                        logger.warning(
+                            f'{command.name} failed ({HCI_Constant.error_name(status)})'
+                        )
+                        raise HCI_Error(status)
+
                 return response
             except Exception as error:
-                logger.warning(f'{color("!!! Exception while sending HCI packet:", "red")} {error}')
-                # raise error
+                logger.warning(
+                    f'{color("!!! Exception while sending HCI packet:", "red")} {error}'
+                )
+                raise error
             finally:
                 self.pending_command = None
                 self.pending_response = None
@@ -202,15 +357,18 @@ class Host(EventEmitter):
         offset = 0
         pb_flag = 0
         while bytes_remaining:
+            # TODO: support different LE/Classic lengths
             data_total_length = min(bytes_remaining, self.hc_le_acl_data_packet_length)
             acl_packet = HCI_AclDataPacket(
-                connection_handle  = connection_handle,
-                pb_flag            = pb_flag,
-                bc_flag            = 0,
-                data_total_length  = data_total_length,
-                data               = l2cap_pdu[offset:offset + data_total_length]
+                connection_handle=connection_handle,
+                pb_flag=pb_flag,
+                bc_flag=0,
+                data_total_length=data_total_length,
+                data=l2cap_pdu[offset : offset + data_total_length],
+            )
+            logger.debug(
+                f'{color("### HOST -> CONTROLLER", "blue")}: (CID={cid}) {acl_packet}'
             )
-            logger.debug(f'{color("### HOST -> CONTROLLER", "blue")}: (CID={cid}) {acl_packet}')
             self.queue_acl_packet(acl_packet)
             pb_flag = 1
             offset += data_total_length
@@ -221,11 +379,17 @@ class Host(EventEmitter):
         self.check_acl_packet_queue()
 
         if len(self.acl_packet_queue):
-            logger.debug(f'{self.acl_packets_in_flight} ACL packets in flight, {len(self.acl_packet_queue)} in queue')
+            logger.debug(
+                f'{self.acl_packets_in_flight} ACL packets in flight, '
+                f'{len(self.acl_packet_queue)} in queue'
+            )
 
     def check_acl_packet_queue(self):
-        # Send all we can
-        while len(self.acl_packet_queue) > 0 and self.acl_packets_in_flight < self.hc_total_num_le_acl_data_packets:
+        # Send all we can (TODO: support different LE/Classic limits)
+        while (
+            len(self.acl_packet_queue) > 0
+            and self.acl_packets_in_flight < self.hc_total_num_le_acl_data_packets
+        ):
             packet = self.acl_packet_queue.pop()
             self.send_hci_packet(packet)
             self.acl_packets_in_flight += 1
@@ -237,7 +401,9 @@ class Host(EventEmitter):
                 if value == command:
                     # Check if the flag is set
                     if octet < len(self.local_supported_commands) and flag_position < 8:
-                        return (self.local_supported_commands[octet] & (1 << flag_position)) != 0
+                        return (
+                            self.local_supported_commands[octet] & (1 << flag_position)
+                        ) != 0
 
         return False
 
@@ -259,15 +425,17 @@ class Host(EventEmitter):
 
     @property
     def supported_le_features(self):
-        return [feature for feature in range(64) if self.local_le_features & (1 << feature)]
+        return [
+            feature for feature in range(64) if self.local_le_features & (1 << feature)
+        ]
 
     # Packet Sink protocol (packets coming from the controller via HCI)
     def on_packet(self, packet):
         hci_packet = HCI_Packet.from_bytes(packet)
         if self.ready or (
-            hci_packet.hci_packet_type == HCI_EVENT_PACKET and
-            hci_packet.event_code == HCI_COMMAND_COMPLETE_EVENT and
-            hci_packet.command_opcode == HCI_RESET_COMMAND
+            hci_packet.hci_packet_type == HCI_EVENT_PACKET
+            and hci_packet.event_code == HCI_COMMAND_COMPLETE_EVENT
+            and hci_packet.command_opcode == HCI_RESET_COMMAND
         ):
             self.on_hci_packet(hci_packet)
         else:
@@ -276,6 +444,9 @@ class Host(EventEmitter):
     def on_hci_packet(self, packet):
         logger.debug(f'{color("### CONTROLLER -> HOST", "green")}: {packet}')
 
+        if self.snooper:
+            self.snooper.snoop(bytes(packet), Snooper.Direction.CONTROLLER_TO_HOST)
+
         # If the packet is a command, invoke the handler for this packet
         if packet.hci_packet_type == HCI_COMMAND_PACKET:
             self.on_hci_command_packet(packet)
@@ -299,12 +470,6 @@ class Host(EventEmitter):
         if connection := self.connections.get(packet.connection_handle):
             connection.on_hci_acl_data_packet(packet)
 
-    def on_gatt_pdu(self, connection, pdu):
-        self.emit('gatt_pdu', connection.handle, pdu)
-
-    def on_smp_pdu(self, connection, pdu):
-        self.emit('smp_pdu', connection.handle, pdu)
-
     def on_l2cap_pdu(self, connection, cid, pdu):
         self.emit('l2cap_pdu', connection.handle, cid, pdu)
 
@@ -312,7 +477,11 @@ class Host(EventEmitter):
         if self.pending_response:
             # Check that it is what we were expecting
             if self.pending_command.op_code != event.command_opcode:
-                logger.warning(f'!!! command result mismatch, expected 0x{self.pending_command.op_code:X} but got 0x{event.command_opcode:X}')
+                logger.warning(
+                    '!!! command result mismatch, expected '
+                    f'0x{self.pending_command.op_code:X} but got '
+                    f'0x{event.command_opcode:X}'
+                )
 
             self.pending_response.set_result(event)
         else:
@@ -326,10 +495,12 @@ class Host(EventEmitter):
 
     def on_hci_command_complete_event(self, event):
         if event.command_opcode == 0:
-            # This is used just for the Num_HCI_Command_Packets field, not related to an actual command
+            # This is used just for the Num_HCI_Command_Packets field, not related to
+            # an actual command
             logger.debug('no-command event')
-        else:
-            return self.on_command_processed(event)
+            return None
+
+        return self.on_command_processed(event)
 
     def on_hci_command_status_event(self, event):
         return self.on_command_processed(event)
@@ -340,36 +511,49 @@ class Host(EventEmitter):
             self.acl_packets_in_flight -= total_packets
             self.check_acl_packet_queue()
         else:
-            logger.warning(color(f'!!! {total_packets} completed but only {self.acl_packets_in_flight} in flight'))
+            logger.warning(
+                color(
+                    '!!! {total_packets} completed but only '
+                    f'{self.acl_packets_in_flight} in flight'
+                )
+            )
             self.acl_packets_in_flight = 0
 
     # Classic only
     def on_hci_connection_request_event(self, event):
-        # For now, just accept everything
-        # TODO: delegate the decision
-        self.send_command_sync(
-            HCI_Accept_Connection_Request_Command(
-                bd_addr = event.bd_addr,
-                role    = 0x01  # Remain the peripheral
-            )
+        # Notify the listeners
+        self.emit(
+            'connection_request',
+            event.bd_addr,
+            event.class_of_device,
+            event.link_type,
         )
 
     def on_hci_le_connection_complete_event(self, event):
         # Check if this is a cancellation
         if event.status == HCI_SUCCESS:
             # Create/update the connection
-            logger.debug(f'### CONNECTION: [0x{event.connection_handle:04X}] {event.peer_address} as {HCI_Constant.role_name(event.role)}')
+            logger.debug(
+                f'### CONNECTION: [0x{event.connection_handle:04X}] '
+                f'{event.peer_address} as {HCI_Constant.role_name(event.role)}'
+            )
 
             connection = self.connections.get(event.connection_handle)
             if connection is None:
-                connection = Connection(self, event.connection_handle, event.role, event.peer_address)
+                connection = Connection(
+                    self,
+                    event.connection_handle,
+                    event.role,
+                    event.peer_address,
+                    BT_LE_TRANSPORT,
+                )
                 self.connections[event.connection_handle] = connection
 
             # Notify the client
             connection_parameters = ConnectionParameters(
-                event.conn_interval,
-                event.conn_latency,
-                event.supervision_timeout
+                event.connection_interval,
+                event.peripheral_latency,
+                event.supervision_timeout,
             )
             self.emit(
                 'connection',
@@ -378,13 +562,15 @@ class Host(EventEmitter):
                 event.peer_address,
                 None,
                 event.role,
-                connection_parameters
+                connection_parameters,
             )
         else:
             logger.debug(f'### CONNECTION FAILED: {event.status}')
 
             # Notify the listeners
-            self.emit('connection_failure', event.status)
+            self.emit(
+                'connection_failure', BT_LE_TRANSPORT, event.peer_address, event.status
+            )
 
     def on_hci_le_enhanced_connection_complete_event(self, event):
         # Just use the same implementation as for the non-enhanced event for now
@@ -393,11 +579,20 @@ class Host(EventEmitter):
     def on_hci_connection_complete_event(self, event):
         if event.status == HCI_SUCCESS:
             # Create/update the connection
-            logger.debug(f'### BR/EDR CONNECTION: [0x{event.connection_handle:04X}] {event.bd_addr}')
+            logger.debug(
+                f'### BR/EDR CONNECTION: [0x{event.connection_handle:04X}] '
+                f'{event.bd_addr}'
+            )
 
             connection = self.connections.get(event.connection_handle)
             if connection is None:
-                connection = Connection(self, event.connection_handle, BT_CENTRAL_ROLE, event.bd_addr)
+                connection = Connection(
+                    self,
+                    event.connection_handle,
+                    BT_CENTRAL_ROLE,
+                    event.bd_addr,
+                    BT_BR_EDR_TRANSPORT,
+                )
                 self.connections[event.connection_handle] = connection
 
             # Notify the client
@@ -408,13 +603,15 @@ class Host(EventEmitter):
                 event.bd_addr,
                 None,
                 BT_CENTRAL_ROLE,
-                None
+                None,
             )
         else:
             logger.debug(f'### BR/EDR CONNECTION FAILED: {event.status}')
 
             # Notify the client
-            self.emit('connection_failure', event.connection_handle, event.status)
+            self.emit(
+                'connection_failure', BT_BR_EDR_TRANSPORT, event.bd_addr, event.status
+            )
 
     def on_hci_disconnection_complete_event(self, event):
         # Find the connection
@@ -423,7 +620,12 @@ class Host(EventEmitter):
             return
 
         if event.status == HCI_SUCCESS:
-            logger.debug(f'### DISCONNECTION: [0x{event.connection_handle:04X}] {connection.peer_address} as {HCI_Constant.role_name(connection.role)}, reason={event.reason}')
+            logger.debug(
+                f'### DISCONNECTION: [0x{event.connection_handle:04X}] '
+                f'{connection.peer_address} as '
+                f'{HCI_Constant.role_name(connection.role)}, '
+                f'reason={event.reason}'
+            )
             del self.connections[event.connection_handle]
 
             # Notify the listeners
@@ -432,7 +634,7 @@ class Host(EventEmitter):
             logger.debug(f'### DISCONNECTION FAILED: {event.status}')
 
             # Notify the listeners
-            self.emit('disconnection_failure', event.status)
+            self.emit('disconnection_failure', event.connection_handle, event.status)
 
     def on_hci_le_connection_update_complete_event(self, event):
         if (connection := self.connections.get(event.connection_handle)) is None:
@@ -442,13 +644,17 @@ class Host(EventEmitter):
         # Notify the client
         if event.status == HCI_SUCCESS:
             connection_parameters = ConnectionParameters(
-                event.conn_interval,
-                event.conn_latency,
-                event.supervision_timeout
+                event.connection_interval,
+                event.peripheral_latency,
+                event.supervision_timeout,
+            )
+            self.emit(
+                'connection_parameters_update', connection.handle, connection_parameters
             )
-            self.emit('connection_parameters_update', connection.handle, connection_parameters)
         else:
-            self.emit('connection_parameters_update_failure', connection.handle, event.status)
+            self.emit(
+                'connection_parameters_update_failure', connection.handle, event.status
+            )
 
     def on_hci_le_phy_update_complete_event(self, event):
         if (connection := self.connections.get(event.connection_handle)) is None:
@@ -464,13 +670,10 @@ class Host(EventEmitter):
 
     def on_hci_le_advertising_report_event(self, event):
         for report in event.reports:
-            self.emit(
-                'advertising_report',
-                report.address,
-                report.data,
-                report.rssi,
-                report.event_type
-            )
+            self.emit('advertising_report', report)
+
+    def on_hci_le_extended_advertising_report_event(self, event):
+        self.on_hci_le_advertising_report_event(event)
 
     def on_hci_le_remote_connection_parameter_request_event(self, event):
         if event.connection_handle not in self.connections:
@@ -481,13 +684,13 @@ class Host(EventEmitter):
         # TODO: delegate the decision
         self.send_command_sync(
             HCI_LE_Remote_Connection_Parameter_Request_Reply_Command(
-                connection_handle = event.connection_handle,
-                interval_min      = event.interval_min,
-                interval_max      = event.interval_max,
-                latency           = event.latency,
-                timeout           = event.timeout,
-                minimum_ce_length = 0,
-                maximum_ce_length = 0
+                connection_handle=event.connection_handle,
+                interval_min=event.interval_min,
+                interval_max=event.interval_max,
+                max_latency=event.max_latency,
+                timeout=event.timeout,
+                min_ce_length=0,
+                max_ce_length=0,
             )
         )
 
@@ -501,19 +704,23 @@ class Host(EventEmitter):
                 logger.debug('no long term key provider')
                 long_term_key = None
             else:
-                long_term_key = await self.long_term_key_provider(
-                    connection.handle,
-                    event.random_number,
-                    event.encryption_diversifier
+                long_term_key = await self.abort_on(
+                    'flush',
+                    # pylint: disable-next=not-callable
+                    self.long_term_key_provider(
+                        connection.handle,
+                        event.random_number,
+                        event.encryption_diversifier,
+                    ),
                 )
             if long_term_key:
                 response = HCI_LE_Long_Term_Key_Request_Reply_Command(
-                    connection_handle = event.connection_handle,
-                    long_term_key     = long_term_key
+                    connection_handle=event.connection_handle,
+                    long_term_key=long_term_key,
                 )
             else:
                 response = HCI_LE_Long_Term_Key_Request_Negative_Reply_Command(
-                    connection_handle = event.connection_handle
+                    connection_handle=event.connection_handle
                 )
 
             await self.send_command(response)
@@ -528,10 +735,21 @@ class Host(EventEmitter):
 
     def on_hci_role_change_event(self, event):
         if event.status == HCI_SUCCESS:
-            logger.debug(f'role change for {event.bd_addr}: {HCI_Constant.role_name(event.new_role)}')
-            # TODO: lookup the connection and update the role
+            logger.debug(
+                f'role change for {event.bd_addr}: '
+                f'{HCI_Constant.role_name(event.new_role)}'
+            )
+            if connection := self.find_connection_by_bd_addr(
+                event.bd_addr, BT_BR_EDR_TRANSPORT
+            ):
+                connection.role = event.new_role
+            self.emit('role_change', event.bd_addr, event.new_role)
         else:
-            logger.debug(f'role change for {event.bd_addr} failed: {HCI_Constant.error_name(event.status)}')
+            logger.debug(
+                f'role change for {event.bd_addr} failed: '
+                f'{HCI_Constant.error_name(event.status)}'
+            )
+            self.emit('role_change_failure', event.bd_addr, event.status)
 
     def on_hci_le_data_length_change_event(self, event):
         self.emit(
@@ -540,7 +758,7 @@ class Host(EventEmitter):
             event.max_tx_octets,
             event.max_tx_time,
             event.max_rx_octets,
-            event.max_rx_time
+            event.max_rx_time,
         )
 
     def on_hci_authentication_complete_event(self, event):
@@ -548,21 +766,35 @@ class Host(EventEmitter):
         if event.status == HCI_SUCCESS:
             self.emit('connection_authentication', event.connection_handle)
         else:
-            self.emit('connection_authentication_failure', event.connection_handle, event.status)
+            self.emit(
+                'connection_authentication_failure',
+                event.connection_handle,
+                event.status,
+            )
 
     def on_hci_encryption_change_event(self, event):
         # Notify the client
         if event.status == HCI_SUCCESS:
-            self.emit('connection_encryption_change', event.connection_handle, event.encryption_enabled)
+            self.emit(
+                'connection_encryption_change',
+                event.connection_handle,
+                event.encryption_enabled,
+            )
         else:
-            self.emit('connection_encryption_failure', event.connection_handle, event.status)
+            self.emit(
+                'connection_encryption_failure', event.connection_handle, event.status
+            )
 
     def on_hci_encryption_key_refresh_complete_event(self, event):
         # Notify the client
         if event.status == HCI_SUCCESS:
             self.emit('connection_encryption_key_refresh', event.connection_handle)
         else:
-            self.emit('connection_encryption_key_refresh_failure', event.connection_handle, event.status)
+            self.emit(
+                'connection_encryption_key_refresh_failure',
+                event.connection_handle,
+                event.status,
+            )
 
     def on_hci_link_supervision_timeout_changed_event(self, event):
         pass
@@ -574,20 +806,20 @@ class Host(EventEmitter):
         pass
 
     def on_hci_link_key_notification_event(self, event):
-        logger.debug(f'link key for {event.bd_addr}: {event.link_key.hex()}, type={HCI_Constant.link_key_type_name(event.key_type)}')
+        logger.debug(
+            f'link key for {event.bd_addr}: {event.link_key.hex()}, '
+            f'type={HCI_Constant.link_key_type_name(event.key_type)}'
+        )
         self.emit('link_key', event.bd_addr, event.link_key, event.key_type)
 
     def on_hci_simple_pairing_complete_event(self, event):
-        logger.debug(f'simple pairing complete for {event.bd_addr}: status={HCI_Constant.status_name(event.status)}')
+        logger.debug(
+            f'simple pairing complete for {event.bd_addr}: '
+            f'status={HCI_Constant.status_name(event.status)}'
+        )
 
     def on_hci_pin_code_request_event(self, event):
-        # For now, just refuse all requests
-        # TODO: delegate the decision
-        self.send_command_sync(
-            HCI_PIN_Code_Request_Negative_Reply_Command(
-                bd_addr = event.bd_addr
-            )
-        )
+        self.emit('pin_code_request', event.bd_addr)
 
     def on_hci_link_key_request_event(self, event):
         async def send_link_key():
@@ -595,15 +827,18 @@ class Host(EventEmitter):
                 logger.debug('no link key provider')
                 link_key = None
             else:
-                link_key = await self.link_key_provider(event.bd_addr)
+                link_key = await self.abort_on(
+                    'flush',
+                    # pylint: disable-next=not-callable
+                    self.link_key_provider(event.bd_addr),
+                )
             if link_key:
                 response = HCI_Link_Key_Request_Reply_Command(
-                    bd_addr  = event.bd_addr,
-                    link_key = link_key
+                    bd_addr=event.bd_addr, link_key=link_key
                 )
             else:
                 response = HCI_Link_Key_Request_Negative_Reply_Command(
-                    bd_addr = event.bd_addr
+                    bd_addr=event.bd_addr
                 )
 
             await self.send_command(response)
@@ -617,12 +852,21 @@ class Host(EventEmitter):
         pass
 
     def on_hci_user_confirmation_request_event(self, event):
-        self.emit('authentication_user_confirmation_request', event.bd_addr, event.numeric_value)
+        self.emit(
+            'authentication_user_confirmation_request',
+            event.bd_addr,
+            event.numeric_value,
+        )
 
     def on_hci_user_passkey_request_event(self, event):
         self.emit('authentication_user_passkey_request', event.bd_addr)
 
-    def on_hci_inquiry_complete_event(self, event):
+    def on_hci_user_passkey_notification_event(self, event):
+        self.emit(
+            'authentication_user_passkey_notification', event.bd_addr, event.passkey
+        )
+
+    def on_hci_inquiry_complete_event(self, _event):
         self.emit('inquiry_complete')
 
     def on_hci_inquiry_result_with_rssi_event(self, event):
@@ -632,7 +876,7 @@ class Host(EventEmitter):
                 response.bd_addr,
                 response.class_of_device,
                 b'',
-                response.rssi
+                response.rssi,
             )
 
     def on_hci_extended_inquiry_result_event(self, event):
@@ -641,7 +885,7 @@ class Host(EventEmitter):
             event.bd_addr,
             event.class_of_device,
             event.extended_inquiry_response,
-            event.rssi
+            event.rssi,
         )
 
     def on_hci_remote_name_request_complete_event(self, event):
@@ -649,3 +893,10 @@ class Host(EventEmitter):
             self.emit('remote_name_failure', event.bd_addr, event.status)
         else:
             self.emit('remote_name', event.bd_addr, event.remote_name)
+
+    def on_hci_remote_host_supported_features_notification_event(self, event):
+        self.emit(
+            'remote_host_supported_features',
+            event.bd_addr,
+            event.host_supported_features,
+        )

bumble/keys.py

@@ -20,13 +20,19 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
+import asyncio
 import logging
 import os
 import json
-from colors import color
+from typing import TYPE_CHECKING, Optional
 
+from .colors import color
 from .hci import Address
 
+if TYPE_CHECKING:
+    from .device import Device
+
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -38,10 +44,10 @@ logger = logging.getLogger(__name__)
 class PairingKeys:
     class Key:
         def __init__(self, value, authenticated=False, ediv=None, rand=None):
-            self.value         = value
+            self.value = value
             self.authenticated = authenticated
-            self.ediv          = ediv
-            self.rand          = rand
+            self.ediv = ediv
+            self.rand = rand
 
         @classmethod
         def from_dict(cls, key_dict):
@@ -64,31 +70,33 @@ class PairingKeys:
             return key_dict
 
     def __init__(self):
-        self.address_type   = None
-        self.ltk            = None
-        self.ltk_central    = None
+        self.address_type = None
+        self.ltk = None
+        self.ltk_central = None
         self.ltk_peripheral = None
-        self.irk            = None
-        self.csrk           = None
-        self.link_key       = None  # Classic
+        self.irk = None
+        self.csrk = None
+        self.link_key = None  # Classic
 
     @staticmethod
     def key_from_dict(keys_dict, key_name):
         key_dict = keys_dict.get(key_name)
-        if key_dict is not None:
-            return PairingKeys.Key.from_dict(key_dict)
+        if key_dict is None:
+            return None
+
+        return PairingKeys.Key.from_dict(key_dict)
 
     @staticmethod
     def from_dict(keys_dict):
         keys = PairingKeys()
 
-        keys.address_type   = keys_dict.get('address_type')
-        keys.ltk            = PairingKeys.key_from_dict(keys_dict, 'ltk')
-        keys.ltk_central    = PairingKeys.key_from_dict(keys_dict, 'ltk_central')
+        keys.address_type = keys_dict.get('address_type')
+        keys.ltk = PairingKeys.key_from_dict(keys_dict, 'ltk')
+        keys.ltk_central = PairingKeys.key_from_dict(keys_dict, 'ltk_central')
         keys.ltk_peripheral = PairingKeys.key_from_dict(keys_dict, 'ltk_peripheral')
-        keys.irk            = PairingKeys.key_from_dict(keys_dict, 'irk')
-        keys.csrk           = PairingKeys.key_from_dict(keys_dict, 'csrk')
-        keys.link_key       = PairingKeys.key_from_dict(keys_dict, 'link_key')
+        keys.irk = PairingKeys.key_from_dict(keys_dict, 'irk')
+        keys.csrk = PairingKeys.key_from_dict(keys_dict, 'csrk')
+        keys.link_key = PairingKeys.key_from_dict(keys_dict, 'link_key')
 
         return keys
 
@@ -120,13 +128,13 @@ class PairingKeys:
 
     def print(self, prefix=''):
         keys_dict = self.to_dict()
-        for (property, value) in keys_dict.items():
-            if type(value) is dict:
-                print(f'{prefix}{color(property, "cyan")}:')
+        for (container_property, value) in keys_dict.items():
+            if isinstance(value, dict):
+                print(f'{prefix}{color(container_property, "cyan")}:')
                 for (key_property, key_value) in value.items():
                     print(f'{prefix}  {color(key_property, "green")}: {key_value}')
             else:
-                print(f'{prefix}{color(property, "cyan")}: {value}')
+                print(f'{prefix}{color(container_property, "cyan")}: {value}')
 
 
 # -----------------------------------------------------------------------------
@@ -137,12 +145,16 @@ class KeyStore:
     async def update(self, name, keys):
         pass
 
-    async def get(self, name):
+    async def get(self, _name):
         return PairingKeys()
 
     async def get_all(self):
         return []
 
+    async def delete_all(self):
+        all_keys = await self.get_all()
+        await asyncio.gather(*(self.delete(name) for (name, _) in all_keys))
+
     async def get_resolving_keys(self):
         all_keys = await self.get_all()
         resolving_keys = []
@@ -161,26 +173,26 @@ class KeyStore:
         separator = ''
         for (name, keys) in entries:
             print(separator + prefix + color(name, 'yellow'))
-            keys.print(prefix = prefix + '  ')
+            keys.print(prefix=prefix + '  ')
             separator = '\n'
 
     @staticmethod
-    def create_for_device(device_config):
-        if device_config.keystore is None:
+    def create_for_device(device: Device) -> Optional[KeyStore]:
+        if device.config.keystore is None:
             return None
 
-        keystore_type = device_config.keystore.split(':', 1)[0]
+        keystore_type = device.config.keystore.split(':', 1)[0]
         if keystore_type == 'JsonKeyStore':
-            return JsonKeyStore.from_device_config(device_config)
+            return JsonKeyStore.from_device(device)
 
         return None
 
 
 # -----------------------------------------------------------------------------
 class JsonKeyStore(KeyStore):
-    APP_NAME          = 'Bumble'
-    APP_AUTHOR        = 'Google'
-    KEYS_DIR          = 'Pairing'
+    APP_NAME = 'Bumble'
+    APP_AUTHOR = 'Google'
+    KEYS_DIR = 'Pairing'
     DEFAULT_NAMESPACE = '__DEFAULT__'
 
     def __init__(self, namespace, filename=None):
@@ -188,12 +200,17 @@ class JsonKeyStore(KeyStore):
 
         if filename is None:
             # Use a default for the current user
+
+            # Import here because this may not exist on all platforms
+            # pylint: disable=import-outside-toplevel
             import appdirs
+
             self.directory_name = os.path.join(
-                appdirs.user_data_dir(self.APP_NAME, self.APP_AUTHOR),
-                self.KEYS_DIR
+                appdirs.user_data_dir(self.APP_NAME, self.APP_AUTHOR), self.KEYS_DIR
+            )
+            json_filename = (
+                f'{self.namespace}.json'.lower().replace(':', '-').replace('/p', '-p')
             )
-            json_filename = f'{self.namespace}.json'.lower().replace(':', '-')
             self.filename = os.path.join(self.directory_name, json_filename)
         else:
             self.filename = filename
@@ -202,11 +219,21 @@ class JsonKeyStore(KeyStore):
         logger.debug(f'JSON keystore: {self.filename}')
 
     @staticmethod
-    def from_device_config(device_config):
-        params = device_config.keystore.split(':', 1)[1:]
-        namespace = str(device_config.address)
+    def from_device(device: Device) -> Optional[JsonKeyStore]:
+        if not device.config.keystore:
+            return None
+
+        params = device.config.keystore.split(':', 1)[1:]
+
+        # Use a namespace based on the device address
+        if device.public_address not in (Address.ANY, Address.ANY_RANDOM):
+            namespace = str(device.public_address)
+        elif device.random_address != Address.ANY_RANDOM:
+            namespace = str(device.random_address)
+        else:
+            namespace = JsonKeyStore.DEFAULT_NAMESPACE
         if params:
-            filename = params[1]
+            filename = params[0]
         else:
             filename = None
 
@@ -214,7 +241,7 @@ class JsonKeyStore(KeyStore):
 
     async def load(self):
         try:
-            with open(self.filename, 'r') as json_file:
+            with open(self.filename, 'r', encoding='utf-8') as json_file:
                 return json.load(json_file)
         except FileNotFoundError:
             return {}
@@ -226,13 +253,13 @@ class JsonKeyStore(KeyStore):
 
         # Save to a temporary file
         temp_filename = self.filename + '.tmp'
-        with open(temp_filename, 'w') as output:
+        with open(temp_filename, 'w', encoding='utf-8') as output:
             json.dump(db, output, sort_keys=True, indent=4)
 
         # Atomically replace the previous file
         os.rename(temp_filename, self.filename)
 
-    async def delete(self, name):
+    async def delete(self, name: str) -> None:
         db = await self.load()
 
         namespace = db.get(self.namespace)
@@ -257,9 +284,18 @@ class JsonKeyStore(KeyStore):
         if namespace is None:
             return []
 
-        return [(name, PairingKeys.from_dict(keys)) for (name, keys) in namespace.items()]
+        return [
+            (name, PairingKeys.from_dict(keys)) for (name, keys) in namespace.items()
+        ]
 
-    async def get(self, name):
+    async def delete_all(self):
+        db = await self.load()
+
+        db.pop(self.namespace, None)
+
+        await self.save(db)
+
+    async def get(self, name: str) -> Optional[PairingKeys]:
         db = await self.load()
 
         namespace = db.get(self.namespace)

bumble/link.py

@@ -17,15 +17,17 @@
 # -----------------------------------------------------------------------------
 import logging
 import asyncio
-import websockets
 from functools import partial
-from colors import color
 
+from bumble.core import BT_PERIPHERAL_ROLE, BT_BR_EDR_TRANSPORT, BT_LE_TRANSPORT
+from bumble.colors import color
 from bumble.hci import (
     Address,
     HCI_SUCCESS,
     HCI_CONNECTION_ACCEPT_TIMEOUT_ERROR,
-    HCI_CONNECTION_TIMEOUT_ERROR
+    HCI_CONNECTION_TIMEOUT_ERROR,
+    HCI_PAGE_TIMEOUT_ERROR,
+    HCI_Connection_Complete_Event,
 )
 
 # -----------------------------------------------------------------------------
@@ -47,7 +49,8 @@ def parse_parameters(params_str):
 
 
 # -----------------------------------------------------------------------------
-# TODO: add more support for various LL exchanges (see Vol 6, Part B - 2.4 DATA CHANNEL PDU)
+# TODO: add more support for various LL exchanges
+# (see Vol 6, Part B - 2.4 DATA CHANNEL PDU)
 # -----------------------------------------------------------------------------
 class LocalLink:
     '''
@@ -55,8 +58,13 @@ class LocalLink:
     '''
 
     def __init__(self):
-        self.controllers        = set()
+        self.controllers = set()
         self.pending_connection = None
+        self.pending_classic_connection = None
+
+    ############################################################
+    # Common utils
+    ############################################################
 
     def add_controller(self, controller):
         logger.debug(f'new controller: {controller}')
@@ -71,22 +79,39 @@ class LocalLink:
                 return controller
         return None
 
-    def on_address_changed(self, controller):
-        pass
+    def find_classic_controller(self, address):
+        for controller in self.controllers:
+            if controller.public_address == address:
+                return controller
+        return None
 
     def get_pending_connection(self):
         return self.pending_connection
 
+    ############################################################
+    # LE handlers
+    ############################################################
+
+    def on_address_changed(self, controller):
+        pass
+
     def send_advertising_data(self, sender_address, data):
         # Send the advertising data to all controllers, except the sender
         for controller in self.controllers:
             if controller.random_address != sender_address:
                 controller.on_link_advertising_data(sender_address, data)
 
-    def send_acl_data(self, sender_address, destination_address, data):
+    def send_acl_data(self, sender_controller, destination_address, transport, data):
         # Send the data to the first controller with a matching address
-        if controller := self.find_controller(destination_address):
-            controller.on_link_acl_data(sender_address, data)
+        if transport == BT_LE_TRANSPORT:
+            destination_controller = self.find_controller(destination_address)
+            source_address = sender_controller.random_address
+        elif transport == BT_BR_EDR_TRANSPORT:
+            destination_controller = self.find_classic_controller(destination_address)
+            source_address = sender_controller.public_address
+
+        if destination_controller is not None:
+            destination_controller.on_link_acl_data(source_address, transport, data)
 
     def on_connection_complete(self):
         # Check that we expect this call
@@ -103,23 +128,31 @@ class LocalLink:
             return
 
         # Connect to the first controller with a matching address
-        if peripheral_controller := self.find_controller(le_create_connection_command.peer_address):
-            central_controller.on_link_peripheral_connection_complete(le_create_connection_command, HCI_SUCCESS)
+        if peripheral_controller := self.find_controller(
+            le_create_connection_command.peer_address
+        ):
+            central_controller.on_link_peripheral_connection_complete(
+                le_create_connection_command, HCI_SUCCESS
+            )
             peripheral_controller.on_link_central_connected(central_address)
             return
 
         # No peripheral found
         central_controller.on_link_peripheral_connection_complete(
-            le_create_connection_command,
-            HCI_CONNECTION_ACCEPT_TIMEOUT_ERROR
+            le_create_connection_command, HCI_CONNECTION_ACCEPT_TIMEOUT_ERROR
         )
 
     def connect(self, central_address, le_create_connection_command):
-        logger.debug(f'$$$ CONNECTION {central_address} -> {le_create_connection_command.peer_address}')
+        logger.debug(
+            f'$$$ CONNECTION {central_address} -> '
+            f'{le_create_connection_command.peer_address}'
+        )
         self.pending_connection = (central_address, le_create_connection_command)
         asyncio.get_running_loop().call_soon(self.on_connection_complete)
 
-    def on_disconnection_complete(self, central_address, peripheral_address, disconnect_command):
+    def on_disconnection_complete(
+        self, central_address, peripheral_address, disconnect_command
+    ):
         # Find the controller that initiated the disconnection
         if not (central_controller := self.find_controller(central_address)):
             logger.warning('!!! Initiating controller not found')
@@ -127,16 +160,26 @@ class LocalLink:
 
         # Disconnect from the first controller with a matching address
         if peripheral_controller := self.find_controller(peripheral_address):
-            peripheral_controller.on_link_central_disconnected(central_address, disconnect_command.reason)
+            peripheral_controller.on_link_central_disconnected(
+                central_address, disconnect_command.reason
+            )
 
-        central_controller.on_link_peripheral_disconnection_complete(disconnect_command, HCI_SUCCESS)
+        central_controller.on_link_peripheral_disconnection_complete(
+            disconnect_command, HCI_SUCCESS
+        )
 
     def disconnect(self, central_address, peripheral_address, disconnect_command):
-        logger.debug(f'$$$ DISCONNECTION {central_address} -> {peripheral_address}: reason = {disconnect_command.reason}')
+        logger.debug(
+            f'$$$ DISCONNECTION {central_address} -> '
+            f'{peripheral_address}: reason = {disconnect_command.reason}'
+        )
         args = [central_address, peripheral_address, disconnect_command]
         asyncio.get_running_loop().call_soon(self.on_disconnection_complete, *args)
 
-    def on_connection_encrypted(self, central_address, peripheral_address, rand, ediv, ltk):
+    # pylint: disable=too-many-arguments
+    def on_connection_encrypted(
+        self, central_address, peripheral_address, rand, ediv, ltk
+    ):
         logger.debug(f'*** ENCRYPTION {central_address} -> {peripheral_address}')
 
         if central_controller := self.find_controller(central_address):
@@ -145,6 +188,89 @@ class LocalLink:
         if peripheral_controller := self.find_controller(peripheral_address):
             peripheral_controller.on_link_encrypted(central_address, rand, ediv, ltk)
 
+    ############################################################
+    # Classic handlers
+    ############################################################
+
+    def classic_connect(self, initiator_controller, responder_address):
+        logger.debug(
+            f'[Classic] {initiator_controller.public_address} connects to {responder_address}'
+        )
+        responder_controller = self.find_classic_controller(responder_address)
+        if responder_controller is None:
+            initiator_controller.on_classic_connection_complete(
+                responder_address, HCI_PAGE_TIMEOUT_ERROR
+            )
+            return
+        self.pending_classic_connection = (initiator_controller, responder_controller)
+
+        responder_controller.on_classic_connection_request(
+            initiator_controller.public_address,
+            HCI_Connection_Complete_Event.ACL_LINK_TYPE,
+        )
+
+    def classic_accept_connection(
+        self, responder_controller, initiator_address, responder_role
+    ):
+        logger.debug(
+            f'[Classic] {responder_controller.public_address} accepts to connect {initiator_address}'
+        )
+        initiator_controller = self.find_classic_controller(initiator_address)
+        if initiator_controller is None:
+            responder_controller.on_classic_connection_complete(
+                responder_controller.public_address, HCI_PAGE_TIMEOUT_ERROR
+            )
+            return
+
+        async def task():
+            if responder_role != BT_PERIPHERAL_ROLE:
+                initiator_controller.on_classic_role_change(
+                    responder_controller.public_address, int(not (responder_role))
+                )
+            initiator_controller.on_classic_connection_complete(
+                responder_controller.public_address, HCI_SUCCESS
+            )
+
+        asyncio.create_task(task())
+        responder_controller.on_classic_role_change(
+            initiator_controller.public_address, responder_role
+        )
+        responder_controller.on_classic_connection_complete(
+            initiator_controller.public_address, HCI_SUCCESS
+        )
+        self.pending_classic_connection = None
+
+    def classic_disconnect(self, initiator_controller, responder_address, reason):
+        logger.debug(
+            f'[Classic] {initiator_controller.public_address} disconnects {responder_address}'
+        )
+        responder_controller = self.find_classic_controller(responder_address)
+
+        async def task():
+            initiator_controller.on_classic_disconnected(responder_address, reason)
+
+        asyncio.create_task(task())
+        responder_controller.on_classic_disconnected(
+            initiator_controller.public_address, reason
+        )
+
+    def classic_switch_role(
+        self, initiator_controller, responder_address, initiator_new_role
+    ):
+        responder_controller = self.find_classic_controller(responder_address)
+        if responder_controller is None:
+            return
+
+        async def task():
+            initiator_controller.on_classic_role_change(
+                responder_address, initiator_new_role
+            )
+
+        asyncio.create_task(task())
+        responder_controller.on_classic_role_change(
+            initiator_controller.public_address, int(not (initiator_new_role))
+        )
+
 
 # -----------------------------------------------------------------------------
 class RemoteLink:
@@ -152,15 +278,18 @@ class RemoteLink:
     A Link implementation that communicates with other virtual controllers via a
     WebSocket relay
     '''
+
     def __init__(self, uri):
-        self.controller             = None
-        self.uri                    = uri
-        self.execution_queue        = asyncio.Queue()
-        self.websocket              = asyncio.get_running_loop().create_future()
-        self.rpc_result             = None
-        self.pending_connection     = None
-        self.central_connections    = set()  # List of addresses that we have connected to
-        self.peripheral_connections = set()  # List of addresses that have connected to us
+        self.controller = None
+        self.uri = uri
+        self.execution_queue = asyncio.Queue()
+        self.websocket = asyncio.get_running_loop().create_future()
+        self.rpc_result = None
+        self.pending_connection = None
+        self.central_connections = set()  # List of addresses that we have connected to
+        self.peripheral_connections = (
+            set()
+        )  # List of addresses that have connected to us
 
         # Connect and run asynchronously
         asyncio.create_task(self.run_connection())
@@ -179,6 +308,9 @@ class RemoteLink:
     def get_pending_connection(self):
         return self.pending_connection
 
+    def get_pending_classic_connection(self):
+        return self.pending_classic_connection
+
     async def wait_until_connected(self):
         await self.websocket
 
@@ -192,11 +324,16 @@ class RemoteLink:
             try:
                 await item
             except Exception as error:
-                logger.warning(f'{color("!!! Exception in async handler:", "red")} {error}')
+                logger.warning(
+                    f'{color("!!! Exception in async handler:", "red")} {error}'
+                )
 
     async def run_connection(self):
+        import websockets  # lazy import
+
         # Connect to the relay
         logger.debug(f'connecting to {self.uri}')
+        # pylint: disable-next=no-member
         websocket = await websockets.connect(self.uri)
         self.websocket.set_result(websocket)
         logger.debug(f'connected to {self.uri}')
@@ -227,7 +364,9 @@ class RemoteLink:
             self.central_connections.remove(address)
 
         if address in self.peripheral_connections:
-            self.controller.on_link_central_disconnected(address, HCI_CONNECTION_TIMEOUT_ERROR)
+            self.controller.on_link_central_disconnected(
+                address, HCI_CONNECTION_TIMEOUT_ERROR
+            )
             self.peripheral_connections.remove(address)
 
     async def on_unreachable_received(self, target):
@@ -244,7 +383,9 @@ class RemoteLink:
 
     async def on_advertisement_message_received(self, sender, advertisement):
         try:
-            self.controller.on_link_advertising_data(Address(sender), bytes.fromhex(advertisement))
+            self.controller.on_link_advertising_data(
+                Address(sender), bytes.fromhex(advertisement)
+            )
         except Exception:
             logger.exception('exception')
 
@@ -263,11 +404,11 @@ class RemoteLink:
         self.controller.on_link_central_connected(Address(sender))
 
         # Accept the connection by responding to it
-        await self.send_targetted_message(sender, 'connected')
+        await self.send_targeted_message(sender, 'connected')
 
     async def on_connected_message_received(self, sender, _):
         if not self.pending_connection:
-            logger.warn('received a connection ack, but no connection is pending')
+            logger.warning('received a connection ack, but no connection is pending')
             return
 
         # Remember the connection
@@ -275,7 +416,9 @@ class RemoteLink:
 
         # Notify the controller
         logger.debug(f'connected to peripheral {self.pending_connection.peer_address}')
-        self.controller.on_link_peripheral_connection_complete(self.pending_connection, HCI_SUCCESS)
+        self.controller.on_link_peripheral_connection_complete(
+            self.pending_connection, HCI_SUCCESS
+        )
 
     async def on_disconnect_message_received(self, sender, message):
         # Notify the controller
@@ -287,7 +430,7 @@ class RemoteLink:
         if sender in self.peripheral_connections:
             self.peripheral_connections.remove(sender)
 
-    async def on_encrypted_message_received(self, sender, message):
+    async def on_encrypted_message_received(self, sender, _):
         # TODO parse params to get real args
         self.controller.on_link_encrypted(Address(sender), bytes(8), 0, bytes(16))
 
@@ -296,7 +439,7 @@ class RemoteLink:
         websocket = await self.websocket
 
         # Create a future value to hold the eventual result
-        assert(self.rpc_result is None)
+        assert self.rpc_result is None
         self.rpc_result = asyncio.get_running_loop().create_future()
 
         # Send the command
@@ -309,7 +452,7 @@ class RemoteLink:
 
         # TODO: parse the result
 
-    async def send_targetted_message(self, target, message):
+    async def send_targeted_message(self, target, message):
         # Ensure we have a connection
         websocket = await self.websocket
 
@@ -326,35 +469,62 @@ class RemoteLink:
         self.execute(self.notify_address_changed)
 
     async def send_advertising_data_to_relay(self, data):
-        await self.send_targetted_message('*', f'advertisement:{data.hex()}')
+        await self.send_targeted_message('*', f'advertisement:{data.hex()}')
 
-    def send_advertising_data(self, sender_address, data):
+    def send_advertising_data(self, _, data):
         self.execute(partial(self.send_advertising_data_to_relay, data))
 
     async def send_acl_data_to_relay(self, peer_address, data):
-        await self.send_targetted_message(peer_address, f'acl:{data.hex()}')
+        await self.send_targeted_message(peer_address, f'acl:{data.hex()}')
 
-    def send_acl_data(self, sender_address, peer_address, data):
+    def send_acl_data(self, _, peer_address, _transport, data):
+        # TODO: handle different transport
         self.execute(partial(self.send_acl_data_to_relay, peer_address, data))
 
     async def send_connection_request_to_relay(self, peer_address):
-        await self.send_targetted_message(peer_address, 'connect')
+        await self.send_targeted_message(peer_address, 'connect')
 
-    def connect(self, central_address, le_create_connection_command):
+    def connect(self, _, le_create_connection_command):
         if self.pending_connection:
-            logger.warn('connection already pending')
+            logger.warning('connection already pending')
             return
         self.pending_connection = le_create_connection_command
-        self.execute(partial(self.send_connection_request_to_relay, str(le_create_connection_command.peer_address)))
+        self.execute(
+            partial(
+                self.send_connection_request_to_relay,
+                str(le_create_connection_command.peer_address),
+            )
+        )
 
     def on_disconnection_complete(self, disconnect_command):
-        self.controller.on_link_peripheral_disconnection_complete(disconnect_command, HCI_SUCCESS)
+        self.controller.on_link_peripheral_disconnection_complete(
+            disconnect_command, HCI_SUCCESS
+        )
 
     def disconnect(self, central_address, peripheral_address, disconnect_command):
-        logger.debug(f'disconnect {central_address} -> {peripheral_address}: reason = {disconnect_command.reason}')
-        self.execute(partial(self.send_targetted_message, peripheral_address, f'disconnect:reason={disconnect_command.reason}'))
-        asyncio.get_running_loop().call_soon(self.on_disconnection_complete, disconnect_command)
+        logger.debug(
+            f'disconnect {central_address} -> '
+            f'{peripheral_address}: reason = {disconnect_command.reason}'
+        )
+        self.execute(
+            partial(
+                self.send_targeted_message,
+                peripheral_address,
+                f'disconnect:reason={disconnect_command.reason}',
+            )
+        )
+        asyncio.get_running_loop().call_soon(
+            self.on_disconnection_complete, disconnect_command
+        )
 
-    def on_connection_encrypted(self, central_address, peripheral_address, rand, ediv, ltk):
-        asyncio.get_running_loop().call_soon(self.controller.on_link_encrypted, peripheral_address, rand, ediv, ltk)
-        self.execute(partial(self.send_targetted_message, peripheral_address, f'encrypted:ltk={ltk.hex()}'))
+    def on_connection_encrypted(self, _, peripheral_address, rand, ediv, ltk):
+        asyncio.get_running_loop().call_soon(
+            self.controller.on_link_encrypted, peripheral_address, rand, ediv, ltk
+        )
+        self.execute(
+            partial(
+                self.send_targeted_message,
+                peripheral_address,
+                f'encrypted:ltk={ltk.hex()}',
+            )
+        )

bumble/profiles/asha_service.py

@@ -0,0 +1,188 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import struct
+import logging
+from typing import List
+from ..core import AdvertisingData
+from ..device import Device, Connection
+from ..gatt import (
+    GATT_ASHA_SERVICE,
+    GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
+    GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
+    GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
+    GATT_ASHA_VOLUME_CHARACTERISTIC,
+    GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
+    TemplateService,
+    Characteristic,
+    CharacteristicValue,
+)
+from ..utils import AsyncRunner
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+class AshaService(TemplateService):
+    UUID = GATT_ASHA_SERVICE
+    OPCODE_START = 1
+    OPCODE_STOP = 2
+    OPCODE_STATUS = 3
+    PROTOCOL_VERSION = 0x01
+    RESERVED_FOR_FUTURE_USE = [00, 00]
+    FEATURE_MAP = [0x01]  # [LE CoC audio output streaming supported]
+    SUPPORTED_CODEC_ID = [0x02, 0x01]  # Codec IDs [G.722 at 16 kHz]
+    RENDER_DELAY = [00, 00]
+
+    def __init__(self, capability: int, hisyncid: List[int], device: Device, psm=0):
+        self.hisyncid = hisyncid
+        self.capability = capability  # Device Capabilities [Left, Monaural]
+        self.device = device
+        self.audio_out_data = b''
+        self.psm = psm  # a non-zero psm is mainly for testing purpose
+
+        # Handler for volume control
+        def on_volume_write(connection, value):
+            logger.info(f'--- VOLUME Write:{value[0]}')
+            self.emit('volume', connection, value[0])
+
+        # Handler for audio control commands
+        def on_audio_control_point_write(connection: Connection, value):
+            logger.info(f'--- AUDIO CONTROL POINT Write:{value.hex()}')
+            opcode = value[0]
+            if opcode == AshaService.OPCODE_START:
+                # Start
+                audio_type = ('Unknown', 'Ringtone', 'Phone Call', 'Media')[value[2]]
+                logger.info(
+                    f'### START: codec={value[1]}, '
+                    f'audio_type={audio_type}, '
+                    f'volume={value[3]}, '
+                    f'otherstate={value[4]}'
+                )
+                self.emit(
+                    'start',
+                    connection,
+                    {
+                        'codec': value[1],
+                        'audiotype': value[2],
+                        'volume': value[3],
+                        'otherstate': value[4],
+                    },
+                )
+            elif opcode == AshaService.OPCODE_STOP:
+                logger.info('### STOP')
+                self.emit('stop', connection)
+            elif opcode == AshaService.OPCODE_STATUS:
+                logger.info(f'### STATUS: connected={value[1]}')
+
+            # OPCODE_STATUS does not need audio status point update
+            if opcode != AshaService.OPCODE_STATUS:
+                AsyncRunner.spawn(
+                    device.notify_subscribers(
+                        self.audio_status_characteristic, force=True
+                    )
+                )
+
+        self.read_only_properties_characteristic = Characteristic(
+            GATT_ASHA_READ_ONLY_PROPERTIES_CHARACTERISTIC,
+            Characteristic.Properties.READ,
+            Characteristic.READABLE,
+            bytes(
+                [
+                    AshaService.PROTOCOL_VERSION,  # Version
+                    self.capability,
+                ]
+            )
+            + bytes(self.hisyncid)
+            + bytes(AshaService.FEATURE_MAP)
+            + bytes(AshaService.RENDER_DELAY)
+            + bytes(AshaService.RESERVED_FOR_FUTURE_USE)
+            + bytes(AshaService.SUPPORTED_CODEC_ID),
+        )
+
+        self.audio_control_point_characteristic = Characteristic(
+            GATT_ASHA_AUDIO_CONTROL_POINT_CHARACTERISTIC,
+            Characteristic.Properties.WRITE
+            | Characteristic.Properties.WRITE_WITHOUT_RESPONSE,
+            Characteristic.WRITEABLE,
+            CharacteristicValue(write=on_audio_control_point_write),
+        )
+        self.audio_status_characteristic = Characteristic(
+            GATT_ASHA_AUDIO_STATUS_CHARACTERISTIC,
+            Characteristic.Properties.READ | Characteristic.Properties.NOTIFY,
+            Characteristic.READABLE,
+            bytes([0]),
+        )
+        self.volume_characteristic = Characteristic(
+            GATT_ASHA_VOLUME_CHARACTERISTIC,
+            Characteristic.Properties.WRITE_WITHOUT_RESPONSE,
+            Characteristic.WRITEABLE,
+            CharacteristicValue(write=on_volume_write),
+        )
+
+        # Register an L2CAP CoC server
+        def on_coc(channel):
+            def on_data(data):
+                logging.debug(f'<<< data received:{data}')
+
+                self.emit('data', channel.connection, data)
+                self.audio_out_data += data
+
+            channel.sink = on_data
+
+        # let the server find a free PSM
+        self.psm = self.device.register_l2cap_channel_server(self.psm, on_coc, 8)
+        self.le_psm_out_characteristic = Characteristic(
+            GATT_ASHA_LE_PSM_OUT_CHARACTERISTIC,
+            Characteristic.Properties.READ,
+            Characteristic.READABLE,
+            struct.pack('<H', self.psm),
+        )
+
+        characteristics = [
+            self.read_only_properties_characteristic,
+            self.audio_control_point_characteristic,
+            self.audio_status_characteristic,
+            self.volume_characteristic,
+            self.le_psm_out_characteristic,
+        ]
+
+        super().__init__(characteristics)
+
+    def get_advertising_data(self):
+        # Advertisement only uses 4 least significant bytes of the HiSyncId.
+        return bytes(
+            AdvertisingData(
+                [
+                    (
+                        AdvertisingData.SERVICE_DATA_16_BIT_UUID,
+                        bytes(GATT_ASHA_SERVICE)
+                        + bytes(
+                            [
+                                AshaService.PROTOCOL_VERSION,
+                                self.capability,
+                            ]
+                        )
+                        + bytes(self.hisyncid[:4]),
+                    ),
+                ]
+            )
+        )

bumble/profiles/battery_service.py

@@ -23,7 +23,7 @@ from ..gatt import (
     TemplateService,
     Characteristic,
     CharacteristicValue,
-    PackedCharacteristicAdapter
+    PackedCharacteristicAdapter,
 )
 
 
@@ -36,11 +36,11 @@ class BatteryService(TemplateService):
         self.battery_level_characteristic = PackedCharacteristicAdapter(
             Characteristic(
                 GATT_BATTERY_LEVEL_CHARACTERISTIC,
-                Characteristic.READ | Characteristic.NOTIFY,
+                Characteristic.Properties.READ | Characteristic.Properties.NOTIFY,
                 Characteristic.READABLE,
-                CharacteristicValue(read=read_battery_level)
+                CharacteristicValue(read=read_battery_level),
             ),
-            format=BatteryService.BATTERY_LEVEL_FORMAT
+            pack_format=BatteryService.BATTERY_LEVEL_FORMAT,
         )
         super().__init__([self.battery_level_characteristic])
 
@@ -52,10 +52,11 @@ class BatteryServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy):
         self.service_proxy = service_proxy
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_BATTERY_LEVEL_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_BATTERY_LEVEL_CHARACTERISTIC
+        ):
             self.battery_level = PackedCharacteristicAdapter(
-                characteristics[0],
-                format=BatteryService.BATTERY_LEVEL_FORMAT
+                characteristics[0], pack_format=BatteryService.BATTERY_LEVEL_FORMAT
             )
         else:
             self.battery_level = None

bumble/profiles/device_information_service.py

@@ -17,7 +17,7 @@
 # Imports
 # -----------------------------------------------------------------------------
 import struct
-from typing import Tuple
+from typing import Optional, Tuple
 
 from ..gatt_client import ProfileServiceProxy
 from ..gatt import (
@@ -33,7 +33,7 @@ from ..gatt import (
     TemplateService,
     Characteristic,
     DelegatedCharacteristicAdapter,
-    UTF8CharacteristicAdapter
+    UTF8CharacteristicAdapter,
 )
 
 
@@ -52,49 +52,50 @@ class DeviceInformationService(TemplateService):
 
     def __init__(
         self,
-        manufacturer_name: str = None,
-        model_number: str = None,
-        serial_number: str = None,
-        hardware_revision: str = None,
-        firmware_revision: str = None,
-        software_revision: str = None,
-        system_id: Tuple[int, int] = None,  # (OUI, Manufacturer ID)
-        ieee_regulatory_certification_data_list: bytes = None
+        manufacturer_name: Optional[str] = None,
+        model_number: Optional[str] = None,
+        serial_number: Optional[str] = None,
+        hardware_revision: Optional[str] = None,
+        firmware_revision: Optional[str] = None,
+        software_revision: Optional[str] = None,
+        system_id: Optional[Tuple[int, int]] = None,  # (OUI, Manufacturer ID)
+        ieee_regulatory_certification_data_list: Optional[bytes] = None
         # TODO: pnp_id
     ):
         characteristics = [
             Characteristic(
-                uuid,
-                Characteristic.READ,
-                Characteristic.READABLE,
-                field
+                uuid, Characteristic.Properties.READ, Characteristic.READABLE, field
             )
             for (field, uuid) in (
                 (manufacturer_name, GATT_MANUFACTURER_NAME_STRING_CHARACTERISTIC),
-                (model_number,      GATT_MODEL_NUMBER_STRING_CHARACTERISTIC),
-                (serial_number,     GATT_SERIAL_NUMBER_STRING_CHARACTERISTIC),
+                (model_number, GATT_MODEL_NUMBER_STRING_CHARACTERISTIC),
+                (serial_number, GATT_SERIAL_NUMBER_STRING_CHARACTERISTIC),
                 (hardware_revision, GATT_HARDWARE_REVISION_STRING_CHARACTERISTIC),
                 (firmware_revision, GATT_FIRMWARE_REVISION_STRING_CHARACTERISTIC),
-                (software_revision, GATT_SOFTWARE_REVISION_STRING_CHARACTERISTIC)
+                (software_revision, GATT_SOFTWARE_REVISION_STRING_CHARACTERISTIC),
             )
             if field is not None
         ]
 
         if system_id is not None:
-            characteristics.append(Characteristic(
-                GATT_SYSTEM_ID_CHARACTERISTIC,
-                Characteristic.READ,
-                Characteristic.READABLE,
-                self.pack_system_id(*system_id)
-            ))
+            characteristics.append(
+                Characteristic(
+                    GATT_SYSTEM_ID_CHARACTERISTIC,
+                    Characteristic.Properties.READ,
+                    Characteristic.READABLE,
+                    self.pack_system_id(*system_id),
+                )
+            )
 
         if ieee_regulatory_certification_data_list is not None:
-            characteristics.append(Characteristic(
-                GATT_REGULATORY_CERTIFICATION_DATA_LIST_CHARACTERISTIC,
-                Characteristic.READ,
-                Characteristic.READABLE,
-                ieee_regulatory_certification_data_list
-            ))
+            characteristics.append(
+                Characteristic(
+                    GATT_REGULATORY_CERTIFICATION_DATA_LIST_CHARACTERISTIC,
+                    Characteristic.Properties.READ,
+                    Characteristic.READABLE,
+                    ieee_regulatory_certification_data_list,
+                )
+            )
 
         super().__init__(characteristics)
 
@@ -108,11 +109,11 @@ class DeviceInformationServiceProxy(ProfileServiceProxy):
 
         for (field, uuid) in (
             ('manufacturer_name', GATT_MANUFACTURER_NAME_STRING_CHARACTERISTIC),
-            ('model_number',      GATT_MODEL_NUMBER_STRING_CHARACTERISTIC),
-            ('serial_number',     GATT_SERIAL_NUMBER_STRING_CHARACTERISTIC),
+            ('model_number', GATT_MODEL_NUMBER_STRING_CHARACTERISTIC),
+            ('serial_number', GATT_SERIAL_NUMBER_STRING_CHARACTERISTIC),
             ('hardware_revision', GATT_HARDWARE_REVISION_STRING_CHARACTERISTIC),
             ('firmware_revision', GATT_FIRMWARE_REVISION_STRING_CHARACTERISTIC),
-            ('software_revision', GATT_SOFTWARE_REVISION_STRING_CHARACTERISTIC)
+            ('software_revision', GATT_SOFTWARE_REVISION_STRING_CHARACTERISTIC),
         ):
             if characteristics := service_proxy.get_characteristics_by_uuid(uuid):
                 characteristic = UTF8CharacteristicAdapter(characteristics[0])
@@ -120,16 +121,20 @@ class DeviceInformationServiceProxy(ProfileServiceProxy):
                 characteristic = None
             self.__setattr__(field, characteristic)
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_SYSTEM_ID_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_SYSTEM_ID_CHARACTERISTIC
+        ):
             self.system_id = DelegatedCharacteristicAdapter(
                 characteristics[0],
                 encode=lambda v: DeviceInformationService.pack_system_id(*v),
-                decode=DeviceInformationService.unpack_system_id
+                decode=DeviceInformationService.unpack_system_id,
             )
         else:
             self.system_id = None
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_REGULATORY_CERTIFICATION_DATA_LIST_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_REGULATORY_CERTIFICATION_DATA_LIST_CHARACTERISTIC
+        ):
             self.ieee_regulatory_certification_data_list = characteristics[0]
         else:
             self.ieee_regulatory_certification_data_list = None

bumble/profiles/heart_rate_service.py

@@ -30,25 +30,25 @@ from ..gatt import (
     Characteristic,
     CharacteristicValue,
     DelegatedCharacteristicAdapter,
-    PackedCharacteristicAdapter
+    PackedCharacteristicAdapter,
 )
 
 
 # -----------------------------------------------------------------------------
 class HeartRateService(TemplateService):
-    UUID                            = GATT_HEART_RATE_SERVICE
+    UUID = GATT_HEART_RATE_SERVICE
     HEART_RATE_CONTROL_POINT_FORMAT = 'B'
-    CONTROL_POINT_NOT_SUPPORTED     = 0x80
-    RESET_ENERGY_EXPENDED           = 0x01
+    CONTROL_POINT_NOT_SUPPORTED = 0x80
+    RESET_ENERGY_EXPENDED = 0x01
 
     class BodySensorLocation(IntEnum):
-        OTHER    = 0,
-        CHEST    = 1,
-        WRIST    = 2,
-        FINGER   = 3,
-        HAND     = 4,
-        EAR_LOBE = 5,
-        FOOT     = 6
+        OTHER = (0,)
+        CHEST = (1,)
+        WRIST = (2,)
+        FINGER = (3,)
+        HAND = (4,)
+        EAR_LOBE = (5,)
+        FOOT = 6
 
     class HeartRateMeasurement:
         def __init__(
@@ -56,12 +56,14 @@ class HeartRateService(TemplateService):
             heart_rate,
             sensor_contact_detected=None,
             energy_expended=None,
-            rr_intervals=None
+            rr_intervals=None,
         ):
             if heart_rate < 0 or heart_rate > 0xFFFF:
                 raise ValueError('heart_rate out of range')
 
-            if energy_expended is not None and (energy_expended < 0 or energy_expended > 0xFFFF):
+            if energy_expended is not None and (
+                energy_expended < 0 or energy_expended > 0xFFFF
+            ):
                 raise ValueError('energy_expended out of range')
 
             if rr_intervals:
@@ -69,10 +71,10 @@ class HeartRateService(TemplateService):
                     if rr_interval < 0 or rr_interval * 1024 > 0xFFFF:
                         raise ValueError('rr_intervals out of range')
 
-            self.heart_rate              = heart_rate
+            self.heart_rate = heart_rate
             self.sensor_contact_detected = sensor_contact_detected
-            self.energy_expended         = energy_expended
-            self.rr_intervals            = rr_intervals
+            self.energy_expended = energy_expended
+            self.rr_intervals = rr_intervals
 
         @classmethod
         def from_bytes(cls, data):
@@ -87,7 +89,7 @@ class HeartRateService(TemplateService):
                 offset += 1
 
             if flags & (1 << 2):
-                sensor_contact_detected = (flags & (1 << 1) != 0)
+                sensor_contact_detected = flags & (1 << 1) != 0
             else:
                 sensor_contact_detected = None
 
@@ -119,51 +121,57 @@ class HeartRateService(TemplateService):
                 flags |= ((1 if self.sensor_contact_detected else 0) << 1) | (1 << 2)
 
             if self.energy_expended is not None:
-                flags |= (1 << 3)
+                flags |= 1 << 3
                 data += struct.pack('<H', self.energy_expended)
 
             if self.rr_intervals:
-                flags |= (1 << 4)
-                data += b''.join([
-                    struct.pack('<H', int(rr_interval * 1024))
-                    for rr_interval in self.rr_intervals
-                ])
+                flags |= 1 << 4
+                data += b''.join(
+                    [
+                        struct.pack('<H', int(rr_interval * 1024))
+                        for rr_interval in self.rr_intervals
+                    ]
+                )
 
             return bytes([flags]) + data
 
         def __str__(self):
-            return f'HeartRateMeasurement(heart_rate={self.heart_rate},'\
-                f' sensor_contact_detected={self.sensor_contact_detected},'\
-                f' energy_expended={self.energy_expended},'\
+            return (
+                f'HeartRateMeasurement(heart_rate={self.heart_rate},'
+                f' sensor_contact_detected={self.sensor_contact_detected},'
+                f' energy_expended={self.energy_expended},'
                 f' rr_intervals={self.rr_intervals})'
+            )
 
     def __init__(
         self,
         read_heart_rate_measurement,
         body_sensor_location=None,
-        reset_energy_expended=None
+        reset_energy_expended=None,
     ):
         self.heart_rate_measurement_characteristic = DelegatedCharacteristicAdapter(
             Characteristic(
                 GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
-                Characteristic.NOTIFY,
+                Characteristic.Properties.NOTIFY,
                 0,
-                CharacteristicValue(read=read_heart_rate_measurement)
+                CharacteristicValue(read=read_heart_rate_measurement),
             ),
-            encode=lambda value: bytes(value)
+            # pylint: disable=unnecessary-lambda
+            encode=lambda value: bytes(value),
         )
         characteristics = [self.heart_rate_measurement_characteristic]
 
         if body_sensor_location is not None:
             self.body_sensor_location_characteristic = Characteristic(
                 GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC,
-                Characteristic.READ,
+                Characteristic.Properties.READ,
                 Characteristic.READABLE,
-                bytes([int(body_sensor_location)])
+                bytes([int(body_sensor_location)]),
             )
             characteristics.append(self.body_sensor_location_characteristic)
 
         if reset_energy_expended:
+
             def write_heart_rate_control_point_value(connection, value):
                 if value == self.RESET_ENERGY_EXPENDED:
                     if reset_energy_expended is not None:
@@ -174,11 +182,11 @@ class HeartRateService(TemplateService):
             self.heart_rate_control_point_characteristic = PackedCharacteristicAdapter(
                 Characteristic(
                     GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC,
-                    Characteristic.WRITE,
+                    Characteristic.Properties.WRITE,
                     Characteristic.WRITEABLE,
-                    CharacteristicValue(write=write_heart_rate_control_point_value)
+                    CharacteristicValue(write=write_heart_rate_control_point_value),
                 ),
-                format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT
+                pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
             )
             characteristics.append(self.heart_rate_control_point_characteristic)
 
@@ -192,30 +200,38 @@ class HeartRateServiceProxy(ProfileServiceProxy):
     def __init__(self, service_proxy):
         self.service_proxy = service_proxy
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC
+        ):
             self.heart_rate_measurement = DelegatedCharacteristicAdapter(
                 characteristics[0],
-                decode=HeartRateService.HeartRateMeasurement.from_bytes
+                decode=HeartRateService.HeartRateMeasurement.from_bytes,
             )
         else:
             self.heart_rate_measurement = None
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC
+        ):
             self.body_sensor_location = DelegatedCharacteristicAdapter(
                 characteristics[0],
-                decode=lambda value: HeartRateService.BodySensorLocation(value[0])
+                decode=lambda value: HeartRateService.BodySensorLocation(value[0]),
             )
         else:
             self.body_sensor_location = None
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC):
+        if characteristics := service_proxy.get_characteristics_by_uuid(
+            GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC
+        ):
             self.heart_rate_control_point = PackedCharacteristicAdapter(
                 characteristics[0],
-                format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT
+                pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
             )
         else:
             self.heart_rate_control_point = None
 
     async def reset_energy_expended(self):
         if self.heart_rate_control_point is not None:
-            return await self.heart_rate_control_point.write_value(HeartRateService.RESET_ENERGY_EXPENDED)
+            return await self.heart_rate_control_point.write_value(
+                HeartRateService.RESET_ENERGY_EXPENDED
+            )

bumble/rfcomm.py

@@ -17,10 +17,12 @@
 # -----------------------------------------------------------------------------
 import logging
 import asyncio
-from colors import color
 
-from .utils import EventEmitter
-from .core import InvalidStateError, ProtocolError, ConnectionError
+from pyee import EventEmitter
+
+from . import core
+from .colors import color
+from .core import BT_BR_EDR_TRANSPORT, InvalidStateError, ProtocolError
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -31,6 +33,8 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+
 RFCOMM_PSM = 0x0003
 
 
@@ -97,22 +101,24 @@ RFCOMM_DEFAULT_PREFERRED_MTU      = 1280
 RFCOMM_DYNAMIC_CHANNEL_NUMBER_START = 1
 RFCOMM_DYNAMIC_CHANNEL_NUMBER_END   = 30
 
+# fmt: on
+
 
 # -----------------------------------------------------------------------------
-def fcs(buffer):
-    fcs = 0xFF
+def compute_fcs(buffer):
+    result = 0xFF
     for byte in buffer:
-        fcs = CRC_TABLE[fcs ^ byte]
-    return 0xFF - fcs
+        result = CRC_TABLE[result ^ byte]
+    return 0xFF - result
 
 
 # -----------------------------------------------------------------------------
 class RFCOMM_Frame:
-    def __init__(self, type, c_r, dlci, p_f, information = b'', with_credits = False):
-        self.type        = type
-        self.c_r         = c_r
-        self.dlci        = dlci
-        self.p_f         = p_f
+    def __init__(self, frame_type, c_r, dlci, p_f, information=b'', with_credits=False):
+        self.type = frame_type
+        self.c_r = c_r
+        self.dlci = dlci
+        self.p_f = p_f
         self.information = information
         length = len(information)
         if with_credits:
@@ -123,19 +129,19 @@ class RFCOMM_Frame:
         else:
             # 1-byte length indicator
             self.length = bytes([(length << 1) | 1])
-        self.address  = (dlci << 2) | (c_r << 1) | 1
-        self.control  = type | (p_f << 4)
-        if type == RFCOMM_UIH_FRAME:
-            self.fcs = fcs(bytes([self.address, self.control]))
+        self.address = (dlci << 2) | (c_r << 1) | 1
+        self.control = frame_type | (p_f << 4)
+        if frame_type == RFCOMM_UIH_FRAME:
+            self.fcs = compute_fcs(bytes([self.address, self.control]))
         else:
-            self.fcs = fcs(bytes([self.address, self.control]) + self.length)
+            self.fcs = compute_fcs(bytes([self.address, self.control]) + self.length)
 
     def type_name(self):
         return RFCOMM_FRAME_TYPE_NAMES[self.type]
 
     @staticmethod
     def parse_mcc(data):
-        type = data[0] >> 2
+        mcc_type = data[0] >> 2
         c_r = (data[0] >> 1) & 1
         length = data[1]
         if data[1] & 1:
@@ -143,13 +149,16 @@ class RFCOMM_Frame:
             value = data[2:]
         else:
             length = (data[3] << 7) & (length >> 1)
-            value = data[3:3 + length]
+            value = data[3 : 3 + length]
 
-        return (type, c_r, value)
+        return (mcc_type, c_r, value)
 
     @staticmethod
-    def make_mcc(type, c_r, data):
-        return bytes([(type << 2 | c_r << 1 | 1) & 0xFF, (len(data) & 0x7F) << 1 | 1]) + data
+    def make_mcc(mcc_type, c_r, data):
+        return (
+            bytes([(mcc_type << 2 | c_r << 1 | 1) & 0xFF, (len(data) & 0x7F) << 1 | 1])
+            + data
+        )
 
     @staticmethod
     def sabm(c_r, dlci):
@@ -168,15 +177,17 @@ class RFCOMM_Frame:
         return RFCOMM_Frame(RFCOMM_DISC_FRAME, c_r, dlci, 1)
 
     @staticmethod
-    def uih(c_r, dlci, information, p_f = 0):
-        return RFCOMM_Frame(RFCOMM_UIH_FRAME, c_r, dlci, p_f, information, with_credits = (p_f == 1))
+    def uih(c_r, dlci, information, p_f=0):
+        return RFCOMM_Frame(
+            RFCOMM_UIH_FRAME, c_r, dlci, p_f, information, with_credits=(p_f == 1)
+        )
 
     @staticmethod
     def from_bytes(data):
         # Extract fields
         dlci = (data[0] >> 2) & 0x3F
         c_r = (data[0] >> 1) & 0x01
-        type = data[1] & 0xEF
+        frame_type = data[1] & 0xEF
         p_f = (data[1] >> 4) & 0x01
         length = data[2]
         if length & 0x01:
@@ -188,132 +199,182 @@ class RFCOMM_Frame:
         fcs = data[-1]
 
         # Construct the frame and check the CRC
-        frame = RFCOMM_Frame(type, c_r, dlci, p_f, information)
+        frame = RFCOMM_Frame(frame_type, c_r, dlci, p_f, information)
         if frame.fcs != fcs:
-            logger.warn(f'FCS mismatch: got {fcs:02X}, expected {frame.fcs:02X}')
+            logger.warning(f'FCS mismatch: got {fcs:02X}, expected {frame.fcs:02X}')
             raise ValueError('fcs mismatch')
 
         return frame
 
     def __bytes__(self):
-        return bytes([self.address, self.control]) + self.length + self.information + bytes([self.fcs])
+        return (
+            bytes([self.address, self.control])
+            + self.length
+            + self.information
+            + bytes([self.fcs])
+        )
 
     def __str__(self):
-        return f'{color(self.type_name(), "yellow")}(c/r={self.c_r},dlci={self.dlci},p/f={self.p_f},length={len(self.information)},fcs=0x{self.fcs:02X})'
+        return (
+            f'{color(self.type_name(), "yellow")}'
+            f'(c/r={self.c_r},'
+            f'dlci={self.dlci},'
+            f'p/f={self.p_f},'
+            f'length={len(self.information)},'
+            f'fcs=0x{self.fcs:02X})'
+        )
 
 
 # -----------------------------------------------------------------------------
 class RFCOMM_MCC_PN:
-    def __init__(self, dlci, cl, priority, ack_timer, max_frame_size, max_retransmissions, window_size):
-        self.dlci                = dlci
-        self.cl                  = cl
-        self.priority            = priority
-        self.ack_timer           = ack_timer
-        self.max_frame_size      = max_frame_size
+    def __init__(
+        self,
+        dlci,
+        cl,
+        priority,
+        ack_timer,
+        max_frame_size,
+        max_retransmissions,
+        window_size,
+    ):
+        self.dlci = dlci
+        self.cl = cl
+        self.priority = priority
+        self.ack_timer = ack_timer
+        self.max_frame_size = max_frame_size
         self.max_retransmissions = max_retransmissions
-        self.window_size         = window_size
+        self.window_size = window_size
 
     @staticmethod
     def from_bytes(data):
         return RFCOMM_MCC_PN(
-            dlci                = data[0],
-            cl                  = data[1],
-            priority            = data[2],
-            ack_timer           = data[3],
-            max_frame_size      = data[4] | data[5] << 8,
-            max_retransmissions = data[6],
-            window_size         = data[7]
+            dlci=data[0],
+            cl=data[1],
+            priority=data[2],
+            ack_timer=data[3],
+            max_frame_size=data[4] | data[5] << 8,
+            max_retransmissions=data[6],
+            window_size=data[7],
         )
 
     def __bytes__(self):
-        return bytes([
-            self.dlci & 0xFF,
-            self.cl & 0xFF,
-            self.priority & 0xFF,
-            self.ack_timer & 0xFF,
-            self.max_frame_size & 0xFF,
-            (self.max_frame_size >> 8) & 0xFF,
-            self.max_retransmissions & 0xFF,
-            self.window_size & 0xFF
-        ])
+        return bytes(
+            [
+                self.dlci & 0xFF,
+                self.cl & 0xFF,
+                self.priority & 0xFF,
+                self.ack_timer & 0xFF,
+                self.max_frame_size & 0xFF,
+                (self.max_frame_size >> 8) & 0xFF,
+                self.max_retransmissions & 0xFF,
+                self.window_size & 0xFF,
+            ]
+        )
 
     def __str__(self):
-        return f'PN(dlci={self.dlci},cl={self.cl},priority={self.priority},ack_timer={self.ack_timer},max_frame_size={self.max_frame_size},max_retransmissions={self.max_retransmissions},window_size={self.window_size})'
+        return (
+            f'PN(dlci={self.dlci},'
+            f'cl={self.cl},'
+            f'priority={self.priority},'
+            f'ack_timer={self.ack_timer},'
+            f'max_frame_size={self.max_frame_size},'
+            f'max_retransmissions={self.max_retransmissions},'
+            f'window_size={self.window_size})'
+        )
 
 
 # -----------------------------------------------------------------------------
 class RFCOMM_MCC_MSC:
     def __init__(self, dlci, fc, rtc, rtr, ic, dv):
         self.dlci = dlci
-        self.fc   = fc
-        self.rtc  = rtc
-        self.rtr  = rtr
-        self.ic   = ic
-        self.dv   = dv
+        self.fc = fc
+        self.rtc = rtc
+        self.rtr = rtr
+        self.ic = ic
+        self.dv = dv
 
     @staticmethod
     def from_bytes(data):
         return RFCOMM_MCC_MSC(
-            dlci = data[0] >> 2,
-            fc   = data[1] >> 1 & 1,
-            rtc  = data[1] >> 2 & 1,
-            rtr  = data[1] >> 3 & 1,
-            ic   = data[1] >> 6 & 1,
-            dv   = data[1] >> 7 & 1
+            dlci=data[0] >> 2,
+            fc=data[1] >> 1 & 1,
+            rtc=data[1] >> 2 & 1,
+            rtr=data[1] >> 3 & 1,
+            ic=data[1] >> 6 & 1,
+            dv=data[1] >> 7 & 1,
         )
 
     def __bytes__(self):
-        return bytes([
-            (self.dlci << 2) | 3,
-            1 | self.fc << 1 | self.rtc << 2 | self.rtr << 3 | self.ic << 6 | self.dv << 7
-        ])
+        return bytes(
+            [
+                (self.dlci << 2) | 3,
+                1
+                | self.fc << 1
+                | self.rtc << 2
+                | self.rtr << 3
+                | self.ic << 6
+                | self.dv << 7,
+            ]
+        )
 
     def __str__(self):
-        return f'MSC(dlci={self.dlci},fc={self.fc},rtc={self.rtc},rtr={self.rtr},ic={self.ic},dv={self.dv})'
+        return (
+            f'MSC(dlci={self.dlci},'
+            f'fc={self.fc},'
+            f'rtc={self.rtc},'
+            f'rtr={self.rtr},'
+            f'ic={self.ic},'
+            f'dv={self.dv})'
+        )
 
 
 # -----------------------------------------------------------------------------
 class DLC(EventEmitter):
     # States
-    INIT          = 0x00
-    CONNECTING    = 0x01
-    CONNECTED     = 0x02
+    INIT = 0x00
+    CONNECTING = 0x01
+    CONNECTED = 0x02
     DISCONNECTING = 0x03
-    DISCONNECTED  = 0x04
-    RESET         = 0x05
+    DISCONNECTED = 0x04
+    RESET = 0x05
 
     STATE_NAMES = {
-        INIT:          'INIT',
-        CONNECTING:    'CONNECTING',
-        CONNECTED:     'CONNECTED',
+        INIT: 'INIT',
+        CONNECTING: 'CONNECTING',
+        CONNECTED: 'CONNECTED',
         DISCONNECTING: 'DISCONNECTING',
-        DISCONNECTED:  'DISCONNECTED',
-        RESET:         'RESET'
+        DISCONNECTED: 'DISCONNECTED',
+        RESET: 'RESET',
     }
 
     def __init__(self, multiplexer, dlci, max_frame_size, initial_tx_credits):
         super().__init__()
-        self.multiplexer  = multiplexer
-        self.dlci         = dlci
-        self.rx_credits   = RFCOMM_DEFAULT_INITIAL_RX_CREDITS
+        self.multiplexer = multiplexer
+        self.dlci = dlci
+        self.rx_credits = RFCOMM_DEFAULT_INITIAL_RX_CREDITS
         self.rx_threshold = self.rx_credits // 2
-        self.tx_credits   = initial_tx_credits
-        self.tx_buffer    = b''
-        self.state        = DLC.INIT
-        self.role         = multiplexer.role
-        self.c_r          = 1 if self.role == Multiplexer.INITIATOR else 0
-        self.sink         = None
+        self.tx_credits = initial_tx_credits
+        self.tx_buffer = b''
+        self.state = DLC.INIT
+        self.role = multiplexer.role
+        self.c_r = 1 if self.role == Multiplexer.INITIATOR else 0
+        self.sink = None
+        self.connection_result = None
 
         # Compute the MTU
         max_overhead = 4 + 1  # header with 2-byte length + fcs
-        self.mtu = min(max_frame_size, self.multiplexer.l2cap_channel.mtu - max_overhead)
+        self.mtu = min(
+            max_frame_size, self.multiplexer.l2cap_channel.mtu - max_overhead
+        )
 
     @staticmethod
     def state_name(state):
         return DLC.STATE_NAMES[state]
 
     def change_state(self, new_state):
-        logger.debug(f'{self} state change -> {color(self.state_name(new_state), "magenta")}')
+        logger.debug(
+            f'{self} state change -> {color(self.state_name(new_state), "magenta")}'
+        )
         self.state = new_state
 
     def send_frame(self, frame):
@@ -323,58 +384,40 @@ class DLC(EventEmitter):
         handler = getattr(self, f'on_{frame.type_name()}_frame'.lower())
         handler(frame)
 
-    def on_sabm_frame(self, frame):
+    def on_sabm_frame(self, _frame):
         if self.state != DLC.CONNECTING:
-            logger.warn(color('!!! received SABM when not in CONNECTING state', 'red'))
+            logger.warning(
+                color('!!! received SABM when not in CONNECTING state', 'red')
+            )
             return
 
-        self.send_frame(RFCOMM_Frame.ua(c_r  = 1 - self.c_r, dlci = self.dlci))
+        self.send_frame(RFCOMM_Frame.ua(c_r=1 - self.c_r, dlci=self.dlci))
 
         # Exchange the modem status with the peer
-        msc = RFCOMM_MCC_MSC(
-            dlci = self.dlci,
-            fc   = 0,
-            rtc  = 1,
-            rtr  = 1,
-            ic   = 0,
-            dv   = 1
+        msc = RFCOMM_MCC_MSC(dlci=self.dlci, fc=0, rtc=1, rtr=1, ic=0, dv=1)
+        mcc = RFCOMM_Frame.make_mcc(
+            mcc_type=RFCOMM_MCC_MSC_TYPE, c_r=1, data=bytes(msc)
         )
-        mcc = RFCOMM_Frame.make_mcc(type = RFCOMM_MCC_MSC_TYPE, c_r = 1, data = bytes(msc))
         logger.debug(f'>>> MCC MSC Command: {msc}')
-        self.send_frame(
-            RFCOMM_Frame.uih(
-                c_r         = self.c_r,
-                dlci        = 0,
-                information = mcc
-            )
-        )
+        self.send_frame(RFCOMM_Frame.uih(c_r=self.c_r, dlci=0, information=mcc))
 
         self.change_state(DLC.CONNECTED)
         self.emit('open')
 
-    def on_ua_frame(self, frame):
+    def on_ua_frame(self, _frame):
         if self.state != DLC.CONNECTING:
-            logger.warn(color('!!! received SABM when not in CONNECTING state', 'red'))
+            logger.warning(
+                color('!!! received SABM when not in CONNECTING state', 'red')
+            )
             return
 
         # Exchange the modem status with the peer
-        msc = RFCOMM_MCC_MSC(
-            dlci = self.dlci,
-            fc   = 0,
-            rtc  = 1,
-            rtr  = 1,
-            ic   = 0,
-            dv   = 1
+        msc = RFCOMM_MCC_MSC(dlci=self.dlci, fc=0, rtc=1, rtr=1, ic=0, dv=1)
+        mcc = RFCOMM_Frame.make_mcc(
+            mcc_type=RFCOMM_MCC_MSC_TYPE, c_r=1, data=bytes(msc)
         )
-        mcc = RFCOMM_Frame.make_mcc(type = RFCOMM_MCC_MSC_TYPE, c_r = 1, data = bytes(msc))
         logger.debug(f'>>> MCC MSC Command: {msc}')
-        self.send_frame(
-            RFCOMM_Frame.uih(
-                c_r         = self.c_r,
-                dlci        = 0,
-                information = mcc
-            )
-        )
+        self.send_frame(RFCOMM_Frame.uih(c_r=self.c_r, dlci=0, information=mcc))
 
         self.change_state(DLC.CONNECTED)
         self.multiplexer.on_dlc_open_complete(self)
@@ -383,29 +426,36 @@ class DLC(EventEmitter):
         # TODO: handle all states
         pass
 
-    def on_disc_frame(self, frame):
+    def on_disc_frame(self, _frame):
         # TODO: handle all states
-        self.send_frame(RFCOMM_Frame.ua(c_r = 1 - self.c_r, dlci = self.dlci))
+        self.send_frame(RFCOMM_Frame.ua(c_r=1 - self.c_r, dlci=self.dlci))
 
     def on_uih_frame(self, frame):
         data = frame.information
         if frame.p_f == 1:
             # With credits
-            credits = frame.information[0]
-            self.tx_credits += credits
+            received_credits = frame.information[0]
+            self.tx_credits += received_credits
 
-            logger.debug(f'<<< Credits [{self.dlci}]: received {credits}, total={self.tx_credits}')
+            logger.debug(
+                f'<<< Credits [{self.dlci}]: '
+                f'received {credits}, total={self.tx_credits}'
+            )
             data = data[1:]
 
-        logger.debug(f'{color("<<< Data", "yellow")} [{self.dlci}] {len(data)} bytes, rx_credits={self.rx_credits}: {data.hex()}')
+        logger.debug(
+            f'{color("<<< Data", "yellow")} '
+            f'[{self.dlci}] {len(data)} bytes, '
+            f'rx_credits={self.rx_credits}: {data.hex()}'
+        )
         if len(data) and self.sink:
-            self.sink(data)
+            self.sink(data)  # pylint: disable=not-callable
 
         # Update the credits
         if self.rx_credits > 0:
             self.rx_credits -= 1
         else:
-            logger.warn(color('!!! received frame with no rx credits', 'red'))
+            logger.warning(color('!!! received frame with no rx credits', 'red'))
 
         # Check if there's anything to send (including credits)
         self.process_tx()
@@ -417,69 +467,47 @@ class DLC(EventEmitter):
         if c_r:
             # Command
             logger.debug(f'<<< MCC MSC Command: {msc}')
-            msc = RFCOMM_MCC_MSC(
-                dlci = self.dlci,
-                fc   = 0,
-                rtc  = 1,
-                rtr  = 1,
-                ic   = 0,
-                dv   = 1
+            msc = RFCOMM_MCC_MSC(dlci=self.dlci, fc=0, rtc=1, rtr=1, ic=0, dv=1)
+            mcc = RFCOMM_Frame.make_mcc(
+                mcc_type=RFCOMM_MCC_MSC_TYPE, c_r=0, data=bytes(msc)
             )
-            mcc = RFCOMM_Frame.make_mcc(type = RFCOMM_MCC_MSC_TYPE, c_r = 0, data = bytes(msc))
             logger.debug(f'>>> MCC MSC Response: {msc}')
-            self.send_frame(
-                RFCOMM_Frame.uih(
-                    c_r         = self.c_r,
-                    dlci        = 0,
-                    information = mcc
-                )
-            )
+            self.send_frame(RFCOMM_Frame.uih(c_r=self.c_r, dlci=0, information=mcc))
         else:
             # Response
             logger.debug(f'<<< MCC MSC Response: {msc}')
 
     def connect(self):
-        if not self.state == DLC.INIT:
+        if self.state != DLC.INIT:
             raise InvalidStateError('invalid state')
 
         self.change_state(DLC.CONNECTING)
         self.connection_result = asyncio.get_running_loop().create_future()
-        self.send_frame(
-            RFCOMM_Frame.sabm(
-                c_r  = self.c_r,
-                dlci = self.dlci
-            )
-        )
+        self.send_frame(RFCOMM_Frame.sabm(c_r=self.c_r, dlci=self.dlci))
 
     def accept(self):
-        if not self.state == DLC.INIT:
+        if self.state != DLC.INIT:
             raise InvalidStateError('invalid state')
 
         pn = RFCOMM_MCC_PN(
-            dlci                = self.dlci,
-            cl                  = 0xE0,
-            priority            = 7,
-            ack_timer           = 0,
-            max_frame_size      = RFCOMM_DEFAULT_PREFERRED_MTU,
-            max_retransmissions = 0,
-            window_size         = RFCOMM_DEFAULT_INITIAL_RX_CREDITS
+            dlci=self.dlci,
+            cl=0xE0,
+            priority=7,
+            ack_timer=0,
+            max_frame_size=RFCOMM_DEFAULT_PREFERRED_MTU,
+            max_retransmissions=0,
+            window_size=RFCOMM_DEFAULT_INITIAL_RX_CREDITS,
         )
-        mcc = RFCOMM_Frame.make_mcc(type = RFCOMM_MCC_PN_TYPE, c_r = 0, data = bytes(pn))
+        mcc = RFCOMM_Frame.make_mcc(mcc_type=RFCOMM_MCC_PN_TYPE, c_r=0, data=bytes(pn))
         logger.debug(f'>>> PN Response: {pn}')
-        self.send_frame(
-            RFCOMM_Frame.uih(
-                c_r         = self.c_r,
-                dlci        = 0,
-                information = mcc
-            )
-        )
+        self.send_frame(RFCOMM_Frame.uih(c_r=self.c_r, dlci=0, information=mcc))
         self.change_state(DLC.CONNECTING)
 
     def rx_credits_needed(self):
         if self.rx_credits <= self.rx_threshold:
             return RFCOMM_DEFAULT_INITIAL_RX_CREDITS - self.rx_credits
-        else:
-            return 0
+
+        return 0
 
     def process_tx(self):
         # Send anything we can (or an empty frame if we need to send rx credits)
@@ -487,13 +515,13 @@ class DLC(EventEmitter):
         while (self.tx_buffer and self.tx_credits > 0) or rx_credits_needed > 0:
             # Get the next chunk, up to MTU size
             if rx_credits_needed > 0:
-                chunk = bytes([rx_credits_needed]) + self.tx_buffer[:self.mtu - 1]
-                self.tx_buffer = self.tx_buffer[len(chunk) - 1:]
+                chunk = bytes([rx_credits_needed]) + self.tx_buffer[: self.mtu - 1]
+                self.tx_buffer = self.tx_buffer[len(chunk) - 1 :]
                 self.rx_credits += rx_credits_needed
-                tx_credit_spent = (len(chunk) > 1)
+                tx_credit_spent = len(chunk) > 1
             else:
-                chunk = self.tx_buffer[:self.mtu]
-                self.tx_buffer = self.tx_buffer[len(chunk):]
+                chunk = self.tx_buffer[: self.mtu]
+                self.tx_buffer = self.tx_buffer[len(chunk) :]
                 tx_credit_spent = True
 
             # Update the tx credits
@@ -502,13 +530,17 @@ class DLC(EventEmitter):
                 self.tx_credits -= 1
 
             # Send the frame
-            logger.debug(f'>>> sending {len(chunk)} bytes with {rx_credits_needed} credits, rx_credits={self.rx_credits}, tx_credits={self.tx_credits}')
+            logger.debug(
+                f'>>> sending {len(chunk)} bytes with {rx_credits_needed} credits, '
+                f'rx_credits={self.rx_credits}, '
+                f'tx_credits={self.tx_credits}'
+            )
             self.send_frame(
                 RFCOMM_Frame.uih(
-                    c_r          = self.c_r,
-                    dlci         = self.dlci,
-                    information  = chunk,
-                    p_f          = 1 if rx_credits_needed > 0 else 0
+                    c_r=self.c_r,
+                    dlci=self.dlci,
+                    information=chunk,
+                    p_f=1 if rx_credits_needed > 0 else 0,
                 )
             )
 
@@ -517,8 +549,8 @@ class DLC(EventEmitter):
     # Stream protocol
     def write(self, data):
         # We can only send bytes
-        if type(data) != bytes:
-            if type(data) == str:
+        if not isinstance(data, bytes):
+            if isinstance(data, str):
                 # Automatically convert strings to bytes using UTF-8
                 data = data.encode('utf-8')
             else:
@@ -542,34 +574,34 @@ class Multiplexer(EventEmitter):
     RESPONDER = 0x01
 
     # States
-    INIT          = 0x00
-    CONNECTING    = 0x01
-    CONNECTED     = 0x02
-    OPENING       = 0x03
+    INIT = 0x00
+    CONNECTING = 0x01
+    CONNECTED = 0x02
+    OPENING = 0x03
     DISCONNECTING = 0x04
-    DISCONNECTED  = 0x05
-    RESET         = 0x06
+    DISCONNECTED = 0x05
+    RESET = 0x06
 
     STATE_NAMES = {
-        INIT:          'INIT',
-        CONNECTING:    'CONNECTING',
-        CONNECTED:     'CONNECTED',
-        OPENING:       'OPENING',
+        INIT: 'INIT',
+        CONNECTING: 'CONNECTING',
+        CONNECTED: 'CONNECTED',
+        OPENING: 'OPENING',
         DISCONNECTING: 'DISCONNECTING',
-        DISCONNECTED:  'DISCONNECTED',
-        RESET:         'RESET'
+        DISCONNECTED: 'DISCONNECTED',
+        RESET: 'RESET',
     }
 
     def __init__(self, l2cap_channel, role):
         super().__init__()
-        self.role                 = role
-        self.l2cap_channel        = l2cap_channel
-        self.state                = Multiplexer.INIT
-        self.dlcs                 = {}  # DLCs, by DLCI
-        self.connection_result    = None
+        self.role = role
+        self.l2cap_channel = l2cap_channel
+        self.state = Multiplexer.INIT
+        self.dlcs = {}  # DLCs, by DLCI
+        self.connection_result = None
         self.disconnection_result = None
-        self.open_result          = None
-        self.acceptor             = None
+        self.open_result = None
+        self.acceptor = None
 
         # Become a sink for the L2CAP channel
         l2cap_channel.sink = self.on_pdu
@@ -579,7 +611,9 @@ class Multiplexer(EventEmitter):
         return Multiplexer.STATE_NAMES[state]
 
     def change_state(self, new_state):
-        logger.debug(f'{self} state change -> {color(self.state_name(new_state), "cyan")}')
+        logger.debug(
+            f'{self} state change -> {color(self.state_name(new_state), "cyan")}'
+        )
         self.state = new_state
 
     def send_frame(self, frame):
@@ -595,14 +629,14 @@ class Multiplexer(EventEmitter):
             self.on_frame(frame)
         else:
             if frame.type == RFCOMM_DM_FRAME:
-                # DM responses are for a DLCI, but since we only create the dlc when we receive
-                # a PN response (because we need the parameters), we handle DM frames at the Multiplexer
-                # level
+                # DM responses are for a DLCI, but since we only create the dlc when we
+                # receive a PN response (because we need the parameters), we handle DM
+                # frames at the Multiplexer level
                 self.on_dm_frame(frame)
             else:
                 dlc = self.dlcs.get(frame.dlci)
                 if dlc is None:
-                    logger.warn(f'no dlc for DLCI {frame.dlci}')
+                    logger.warning(f'no dlc for DLCI {frame.dlci}')
                     return
                 dlc.on_frame(frame)
 
@@ -610,14 +644,14 @@ class Multiplexer(EventEmitter):
         handler = getattr(self, f'on_{frame.type_name()}_frame'.lower())
         handler(frame)
 
-    def on_sabm_frame(self, frame):
+    def on_sabm_frame(self, _frame):
         if self.state != Multiplexer.INIT:
             logger.debug('not in INIT state, ignoring SABM')
             return
         self.change_state(Multiplexer.CONNECTED)
-        self.send_frame(RFCOMM_Frame.ua(c_r = 1, dlci = 0))
+        self.send_frame(RFCOMM_Frame.ua(c_r=1, dlci=0))
 
-    def on_ua_frame(self, frame):
+    def on_ua_frame(self, _frame):
         if self.state == Multiplexer.CONNECTING:
             self.change_state(Multiplexer.CONNECTED)
             if self.connection_result:
@@ -629,25 +663,34 @@ class Multiplexer(EventEmitter):
                 self.disconnection_result.set_result(None)
                 self.disconnection_result = None
 
-    def on_dm_frame(self, frame):
+    def on_dm_frame(self, _frame):
         if self.state == Multiplexer.OPENING:
             self.change_state(Multiplexer.CONNECTED)
             if self.open_result:
-                self.open_result.set_exception(ConnectionError(ConnectionError.CONNECTION_REFUSED))
+                self.open_result.set_exception(
+                    core.ConnectionError(
+                        core.ConnectionError.CONNECTION_REFUSED,
+                        BT_BR_EDR_TRANSPORT,
+                        self.l2cap_channel.connection.peer_address,
+                        'rfcomm',
+                    )
+                )
         else:
-            logger.warn(f'unexpected state for DM: {self}')
+            logger.warning(f'unexpected state for DM: {self}')
 
-    def on_disc_frame(self, frame):
+    def on_disc_frame(self, _frame):
         self.change_state(Multiplexer.DISCONNECTED)
-        self.send_frame(RFCOMM_Frame.ua(c_r = 0 if self.role == Multiplexer.INITIATOR else 1, dlci = 0))
+        self.send_frame(
+            RFCOMM_Frame.ua(c_r=0 if self.role == Multiplexer.INITIATOR else 1, dlci=0)
+        )
 
     def on_uih_frame(self, frame):
-        (type, c_r, value) = RFCOMM_Frame.parse_mcc(frame.information)
+        (mcc_type, c_r, value) = RFCOMM_Frame.parse_mcc(frame.information)
 
-        if type == RFCOMM_MCC_PN_TYPE:
+        if mcc_type == RFCOMM_MCC_PN_TYPE:
             pn = RFCOMM_MCC_PN.from_bytes(value)
             self.on_mcc_pn(c_r, pn)
-        elif type == RFCOMM_MCC_MSC_TYPE:
+        elif mcc_type == RFCOMM_MCC_MSC_TYPE:
             mcs = RFCOMM_MCC_MSC.from_bytes(value)
             self.on_mcc_msc(c_r, mcs)
 
@@ -663,7 +706,7 @@ class Multiplexer(EventEmitter):
             if pn.dlci & 1:
                 # Not expected, this is an initiator-side number
                 # TODO: error out
-                logger.warn(f'invalid DLCI: {pn.dlci}')
+                logger.warning(f'invalid DLCI: {pn.dlci}')
             else:
                 if self.acceptor:
                     channel_number = pn.dlci >> 1
@@ -679,10 +722,10 @@ class Multiplexer(EventEmitter):
                         dlc.accept()
                     else:
                         # No acceptor, we're in Disconnected Mode
-                        self.send_frame(RFCOMM_Frame.dm(c_r = 1, dlci = pn.dlci))
+                        self.send_frame(RFCOMM_Frame.dm(c_r=1, dlci=pn.dlci))
                 else:
                     # No acceptor?? shouldn't happen
-                    logger.warn(color('!!! no acceptor registered', 'red'))
+                    logger.warning(color('!!! no acceptor registered', 'red'))
         else:
             # Response
             logger.debug(f'>>> PN Response: {pn}')
@@ -691,12 +734,12 @@ class Multiplexer(EventEmitter):
                 self.dlcs[pn.dlci] = dlc
                 dlc.connect()
             else:
-                logger.warn('ignoring PN response')
+                logger.warning('ignoring PN response')
 
     def on_mcc_msc(self, c_r, msc):
         dlc = self.dlcs.get(msc.dlci)
         if dlc is None:
-            logger.warn(f'no dlc for DLCI {msc.dlci}')
+            logger.warning(f'no dlc for DLCI {msc.dlci}')
             return
         dlc.on_mcc_msc(c_r, msc)
 
@@ -706,7 +749,7 @@ class Multiplexer(EventEmitter):
 
         self.change_state(Multiplexer.CONNECTING)
         self.connection_result = asyncio.get_running_loop().create_future()
-        self.send_frame(RFCOMM_Frame.sabm(c_r = 1, dlci = 0))
+        self.send_frame(RFCOMM_Frame.sabm(c_r=1, dlci=0))
         return await self.connection_result
 
     async def disconnect(self):
@@ -715,34 +758,38 @@ class Multiplexer(EventEmitter):
 
         self.disconnection_result = asyncio.get_running_loop().create_future()
         self.change_state(Multiplexer.DISCONNECTING)
-        self.send_frame(RFCOMM_Frame.disc(c_r = 1 if self.role == Multiplexer.INITIATOR else 0, dlci = 0))
+        self.send_frame(
+            RFCOMM_Frame.disc(
+                c_r=1 if self.role == Multiplexer.INITIATOR else 0, dlci=0
+            )
+        )
         await self.disconnection_result
 
     async def open_dlc(self, channel):
         if self.state != Multiplexer.CONNECTED:
             if self.state == Multiplexer.OPENING:
                 raise InvalidStateError('open already in progress')
-            else:
-                raise InvalidStateError('not connected')
+
+            raise InvalidStateError('not connected')
 
         pn = RFCOMM_MCC_PN(
-            dlci                = channel << 1,
-            cl                  = 0xF0,
-            priority            = 7,
-            ack_timer           = 0,
-            max_frame_size      = RFCOMM_DEFAULT_PREFERRED_MTU,
-            max_retransmissions = 0,
-            window_size         = RFCOMM_DEFAULT_INITIAL_RX_CREDITS
+            dlci=channel << 1,
+            cl=0xF0,
+            priority=7,
+            ack_timer=0,
+            max_frame_size=RFCOMM_DEFAULT_PREFERRED_MTU,
+            max_retransmissions=0,
+            window_size=RFCOMM_DEFAULT_INITIAL_RX_CREDITS,
         )
-        mcc = RFCOMM_Frame.make_mcc(type = RFCOMM_MCC_PN_TYPE, c_r = 1, data = bytes(pn))
+        mcc = RFCOMM_Frame.make_mcc(mcc_type=RFCOMM_MCC_PN_TYPE, c_r=1, data=bytes(pn))
         logger.debug(f'>>> Sending MCC: {pn}')
         self.open_result = asyncio.get_running_loop().create_future()
         self.change_state(Multiplexer.OPENING)
         self.send_frame(
             RFCOMM_Frame.uih(
-                c_r         = 1 if self.role == Multiplexer.INITIATOR else 0,
-                dlci        = 0,
-                information = mcc
+                c_r=1 if self.role == Multiplexer.INITIATOR else 0,
+                dlci=0,
+                information=mcc,
             )
         )
         result = await self.open_result
@@ -762,17 +809,19 @@ class Multiplexer(EventEmitter):
 # -----------------------------------------------------------------------------
 class Client:
     def __init__(self, device, connection):
-        self.device        = device
-        self.connection    = connection
+        self.device = device
+        self.connection = connection
         self.l2cap_channel = None
-        self.multiplexer   = None
+        self.multiplexer = None
 
     async def start(self):
         # Create a new L2CAP connection
         try:
-            self.l2cap_channel = await self.device.l2cap_channel_manager.connect(self.connection, RFCOMM_PSM)
+            self.l2cap_channel = await self.device.l2cap_channel_manager.connect(
+                self.connection, RFCOMM_PSM
+            )
         except ProtocolError as error:
-            logger.warn(f'L2CAP connection failed: {error}')
+            logger.warning(f'L2CAP connection failed: {error}')
             raise
 
         # Create a mutliplexer to manage DLCs with the server
@@ -796,22 +845,34 @@ class Client:
 class Server(EventEmitter):
     def __init__(self, device):
         super().__init__()
-        self.device      = device
+        self.device = device
         self.multiplexer = None
-        self.acceptors   = {}
+        self.acceptors = {}
 
         # Register ourselves with the L2CAP channel manager
         device.register_l2cap_server(RFCOMM_PSM, self.on_connection)
 
-    def listen(self, acceptor):
-        # Find a free channel number
-        for channel in range(RFCOMM_DYNAMIC_CHANNEL_NUMBER_START, RFCOMM_DYNAMIC_CHANNEL_NUMBER_END + 1):
-            if channel not in self.acceptors:
-                self.acceptors[channel] = acceptor
-                return channel
+    def listen(self, acceptor, channel=0):
+        if channel:
+            if channel in self.acceptors:
+                # Busy
+                return 0
+        else:
+            # Find a free channel number
+            for candidate in range(
+                RFCOMM_DYNAMIC_CHANNEL_NUMBER_START,
+                RFCOMM_DYNAMIC_CHANNEL_NUMBER_END + 1,
+            ):
+                if candidate not in self.acceptors:
+                    channel = candidate
+                    break
 
-        # All channels used...
-        return 0
+            if channel == 0:
+                # All channels used...
+                return 0
+
+        self.acceptors[channel] = acceptor
+        return channel
 
     def on_connection(self, l2cap_channel):
         logger.debug(f'+++ new L2CAP connection: {l2cap_channel}')

bumble/sdp.py

@@ -15,12 +15,13 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
 import logging
 import struct
-from colors import color
-import colors
+from typing import Dict, List, Type
 
 from . import core
+from .colors import color
 from .core import InvalidStateError
 from .hci import HCI_Object, name_or_number, key_with_value
 
@@ -33,6 +34,9 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
+# fmt: off
+# pylint: disable=line-too-long
+
 SDP_CONTINUATION_WATCHDOG = 64  # Maximum number of continuations we're willing to do
 
 SDP_PSM = 0x0001
@@ -112,137 +116,162 @@ SDP_PUBLIC_BROWSE_ROOT = core.UUID.from_16_bits(0x1002, 'PublicBrowseRoot')
 # To be used in searches where an attribute ID list allows a range to be specified
 SDP_ALL_ATTRIBUTES_RANGE = (0x0000FFFF, 4)  # Express this as tuple so we can convey the desired encoding size
 
+# fmt: on
+# pylint: enable=line-too-long
+# pylint: disable=invalid-name
+
 
 # -----------------------------------------------------------------------------
 class DataElement:
-    NIL              = 0
+    NIL = 0
     UNSIGNED_INTEGER = 1
-    SIGNED_INTEGER   = 2
-    UUID             = 3
-    TEXT_STRING      = 4
-    BOOLEAN          = 5
-    SEQUENCE         = 6
-    ALTERNATIVE      = 7
-    URL              = 8
+    SIGNED_INTEGER = 2
+    UUID = 3
+    TEXT_STRING = 4
+    BOOLEAN = 5
+    SEQUENCE = 6
+    ALTERNATIVE = 7
+    URL = 8
 
     TYPE_NAMES = {
-        NIL:              'NIL',
+        NIL: 'NIL',
         UNSIGNED_INTEGER: 'UNSIGNED_INTEGER',
-        SIGNED_INTEGER:   'SIGNED_INTEGER',
-        UUID:             'UUID',
-        TEXT_STRING:      'TEXT_STRING',
-        BOOLEAN:          'BOOLEAN',
-        SEQUENCE:         'SEQUENCE',
-        ALTERNATIVE:      'ALTERNATIVE',
-        URL:              'URL'
+        SIGNED_INTEGER: 'SIGNED_INTEGER',
+        UUID: 'UUID',
+        TEXT_STRING: 'TEXT_STRING',
+        BOOLEAN: 'BOOLEAN',
+        SEQUENCE: 'SEQUENCE',
+        ALTERNATIVE: 'ALTERNATIVE',
+        URL: 'URL',
     }
 
     type_constructors = {
-        NIL:              lambda x: DataElement(DataElement.NIL, None),
-        UNSIGNED_INTEGER: lambda x, y: DataElement(DataElement.UNSIGNED_INTEGER, DataElement.unsigned_integer_from_bytes(x), value_size=y),
-        SIGNED_INTEGER:   lambda x, y: DataElement(DataElement.SIGNED_INTEGER, DataElement.signed_integer_from_bytes(x), value_size=y),
-        UUID:             lambda x: DataElement(DataElement.UUID, core.UUID.from_bytes(bytes(reversed(x)))),
-        TEXT_STRING:      lambda x: DataElement(DataElement.TEXT_STRING, x.decode('utf8')),
-        BOOLEAN:          lambda x: DataElement(DataElement.BOOLEAN, x[0] == 1),
-        SEQUENCE:         lambda x: DataElement(DataElement.SEQUENCE, DataElement.list_from_bytes(x)),
-        ALTERNATIVE:      lambda x: DataElement(DataElement.ALTERNATIVE, DataElement.list_from_bytes(x)),
-        URL:              lambda x: DataElement(DataElement.URL, x.decode('utf8'))
+        NIL: lambda x: DataElement(DataElement.NIL, None),
+        UNSIGNED_INTEGER: lambda x, y: DataElement(
+            DataElement.UNSIGNED_INTEGER,
+            DataElement.unsigned_integer_from_bytes(x),
+            value_size=y,
+        ),
+        SIGNED_INTEGER: lambda x, y: DataElement(
+            DataElement.SIGNED_INTEGER,
+            DataElement.signed_integer_from_bytes(x),
+            value_size=y,
+        ),
+        UUID: lambda x: DataElement(
+            DataElement.UUID, core.UUID.from_bytes(bytes(reversed(x)))
+        ),
+        TEXT_STRING: lambda x: DataElement(DataElement.TEXT_STRING, x.decode('utf8')),
+        BOOLEAN: lambda x: DataElement(DataElement.BOOLEAN, x[0] == 1),
+        SEQUENCE: lambda x: DataElement(
+            DataElement.SEQUENCE, DataElement.list_from_bytes(x)
+        ),
+        ALTERNATIVE: lambda x: DataElement(
+            DataElement.ALTERNATIVE, DataElement.list_from_bytes(x)
+        ),
+        URL: lambda x: DataElement(DataElement.URL, x.decode('utf8')),
     }
 
-    def __init__(self, type, value, value_size=None):
-        self.type       = type
-        self.value      = value
+    def __init__(self, element_type, value, value_size=None):
+        self.type = element_type
+        self.value = value
         self.value_size = value_size
-        self.bytes      = None  # Used a cache when parsing from bytes so we can emit a byte-for-byte replica
-        if type == DataElement.UNSIGNED_INTEGER or type == DataElement.SIGNED_INTEGER:
+        # Used as a cache when parsing from bytes so we can emit a byte-for-byte replica
+        self.bytes = None
+        if element_type in (DataElement.UNSIGNED_INTEGER, DataElement.SIGNED_INTEGER):
             if value_size is None:
                 raise ValueError('integer types must have a value size specified')
 
     @staticmethod
-    def nil():
+    def nil() -> DataElement:
         return DataElement(DataElement.NIL, None)
 
     @staticmethod
-    def unsigned_integer(value, value_size):
+    def unsigned_integer(value: int, value_size: int) -> DataElement:
         return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size)
 
     @staticmethod
-    def unsigned_integer_8(value):
+    def unsigned_integer_8(value: int) -> DataElement:
         return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=1)
 
     @staticmethod
-    def unsigned_integer_16(value):
+    def unsigned_integer_16(value: int) -> DataElement:
         return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=2)
 
     @staticmethod
-    def unsigned_integer_32(value):
+    def unsigned_integer_32(value: int) -> DataElement:
         return DataElement(DataElement.UNSIGNED_INTEGER, value, value_size=4)
 
     @staticmethod
-    def signed_integer(value, value_size):
+    def signed_integer(value: int, value_size: int) -> DataElement:
         return DataElement(DataElement.SIGNED_INTEGER, value, value_size)
 
     @staticmethod
-    def signed_integer_8(value):
+    def signed_integer_8(value: int) -> DataElement:
         return DataElement(DataElement.SIGNED_INTEGER, value, value_size=1)
 
     @staticmethod
-    def signed_integer_16(value):
+    def signed_integer_16(value: int) -> DataElement:
         return DataElement(DataElement.SIGNED_INTEGER, value, value_size=2)
 
     @staticmethod
-    def signed_integer_32(value):
+    def signed_integer_32(value: int) -> DataElement:
         return DataElement(DataElement.SIGNED_INTEGER, value, value_size=4)
 
     @staticmethod
-    def uuid(value):
+    def uuid(value: core.UUID) -> DataElement:
         return DataElement(DataElement.UUID, value)
 
     @staticmethod
-    def text_string(value):
+    def text_string(value: str) -> DataElement:
         return DataElement(DataElement.TEXT_STRING, value)
 
     @staticmethod
-    def boolean(value):
+    def boolean(value: bool) -> DataElement:
         return DataElement(DataElement.BOOLEAN, value)
 
     @staticmethod
-    def sequence(value):
+    def sequence(value: List[DataElement]) -> DataElement:
         return DataElement(DataElement.SEQUENCE, value)
 
     @staticmethod
-    def alternative(value):
+    def alternative(value: List[DataElement]) -> DataElement:
         return DataElement(DataElement.ALTERNATIVE, value)
 
     @staticmethod
-    def url(value):
+    def url(value: str) -> DataElement:
         return DataElement(DataElement.URL, value)
 
     @staticmethod
     def unsigned_integer_from_bytes(data):
         if len(data) == 1:
             return data[0]
-        elif len(data) == 2:
+
+        if len(data) == 2:
             return struct.unpack('>H', data)[0]
-        elif len(data) == 4:
+
+        if len(data) == 4:
             return struct.unpack('>I', data)[0]
-        elif len(data) == 8:
+
+        if len(data) == 8:
             return struct.unpack('>Q', data)[0]
-        else:
-            raise ValueError(f'invalid integer length {len(data)}')
+
+        raise ValueError(f'invalid integer length {len(data)}')
 
     @staticmethod
     def signed_integer_from_bytes(data):
         if len(data) == 1:
             return struct.unpack('b', data)[0]
-        elif len(data) == 2:
+
+        if len(data) == 2:
             return struct.unpack('>h', data)[0]
-        elif len(data) == 4:
+
+        if len(data) == 4:
             return struct.unpack('>i', data)[0]
-        elif len(data) == 8:
+
+        if len(data) == 8:
             return struct.unpack('>q', data)[0]
-        else:
-            raise ValueError(f'invalid integer length {len(data)}')
+
+        raise ValueError(f'invalid integer length {len(data)}')
 
     @staticmethod
     def list_from_bytes(data):
@@ -250,7 +279,7 @@ class DataElement:
         while data:
             element = DataElement.from_bytes(data)
             elements.append(element)
-            data = data[len(bytes(element)):]
+            data = data[len(bytes(element)) :]
         return elements
 
     @staticmethod
@@ -260,11 +289,11 @@ class DataElement:
 
     @staticmethod
     def from_bytes(data):
-        type = data[0] >> 3
-        size_index  = data[0] & 7
+        element_type = data[0] >> 3
+        size_index = data[0] & 7
         value_offset = 0
         if size_index == 0:
-            if type == DataElement.NIL:
+            if element_type == DataElement.NIL:
                 value_size = 0
             else:
                 value_size = 1
@@ -286,16 +315,21 @@ class DataElement:
             value_size = struct.unpack('>I', data[1:5])[0]
             value_offset = 4
 
-        value_data = data[1 + value_offset:1 + value_offset + value_size]
-        constructor = DataElement.type_constructors.get(type)
+        value_data = data[1 + value_offset : 1 + value_offset + value_size]
+        constructor = DataElement.type_constructors.get(element_type)
         if constructor:
-            if type == DataElement.UNSIGNED_INTEGER or type == DataElement.SIGNED_INTEGER:
+            if element_type in (
+                DataElement.UNSIGNED_INTEGER,
+                DataElement.SIGNED_INTEGER,
+            ):
                 result = constructor(value_data, value_size)
             else:
                 result = constructor(value_data)
         else:
-            result = DataElement(type, value_data)
-        result.bytes = data[:1 + value_offset + value_size]  # Keep a copy so we can re-serialize to an exact replica
+            result = DataElement(element_type, value_data)
+        result.bytes = data[
+            : 1 + value_offset + value_size
+        ]  # Keep a copy so we can re-serialize to an exact replica
         return result
 
     def to_bytes(self):
@@ -311,7 +345,8 @@ class DataElement:
         elif self.type == DataElement.UNSIGNED_INTEGER:
             if self.value < 0:
                 raise ValueError('UNSIGNED_INTEGER cannot be negative')
-            elif self.value_size == 1:
+
+            if self.value_size == 1:
                 data = struct.pack('B', self.value)
             elif self.value_size == 2:
                 data = struct.pack('>H', self.value)
@@ -334,11 +369,11 @@ class DataElement:
                 raise ValueError('invalid value_size')
         elif self.type == DataElement.UUID:
             data = bytes(reversed(bytes(self.value)))
-        elif self.type == DataElement.TEXT_STRING or self.type == DataElement.URL:
+        elif self.type in (DataElement.TEXT_STRING, DataElement.URL):
             data = self.value.encode('utf8')
         elif self.type == DataElement.BOOLEAN:
             data = bytes([1 if self.value else 0])
-        elif self.type == DataElement.SEQUENCE or self.type == DataElement.ALTERNATIVE:
+        elif self.type in (DataElement.SEQUENCE, DataElement.ALTERNATIVE):
             data = b''.join([bytes(element) for element in self.value])
         else:
             data = self.value
@@ -349,9 +384,11 @@ class DataElement:
             if size != 0:
                 raise ValueError('NIL must be empty')
             size_index = 0
-        elif (self.type == DataElement.UNSIGNED_INTEGER or
-              self.type == DataElement.SIGNED_INTEGER or
-              self.type == DataElement.UUID):
+        elif self.type in (
+            DataElement.UNSIGNED_INTEGER,
+            DataElement.SIGNED_INTEGER,
+            DataElement.UUID,
+        ):
             if size <= 1:
                 size_index = 0
             elif size == 2:
@@ -364,10 +401,12 @@ class DataElement:
                 size_index = 4
             else:
                 raise ValueError('invalid data size')
-        elif (self.type == DataElement.TEXT_STRING or
-              self.type == DataElement.SEQUENCE or
-              self.type == DataElement.ALTERNATIVE or
-              self.type == DataElement.URL):
+        elif self.type in (
+            DataElement.TEXT_STRING,
+            DataElement.SEQUENCE,
+            DataElement.ALTERNATIVE,
+            DataElement.URL,
+        ):
             if size <= 0xFF:
                 size_index = 5
                 size_bytes = bytes([size])
@@ -392,11 +431,19 @@ class DataElement:
         type_name = name_or_number(self.TYPE_NAMES, self.type)
         if self.type == DataElement.NIL:
             value_string = ''
-        elif self.type == DataElement.SEQUENCE or self.type == DataElement.ALTERNATIVE:
+        elif self.type in (DataElement.SEQUENCE, DataElement.ALTERNATIVE):
             container_separator = '\n' if pretty else ''
             element_separator = '\n' if pretty else ','
-            value_string = f'[{container_separator}{element_separator.join([element.to_string(pretty, indentation + 1 if pretty else 0) for element in self.value])}{container_separator}{prefix}]'
-        elif self.type == DataElement.UNSIGNED_INTEGER or self.type == DataElement.SIGNED_INTEGER:
+            elements = [
+                element.to_string(pretty, indentation + 1 if pretty else 0)
+                for element in self.value
+            ]
+            value_string = (
+                f'[{container_separator}'
+                f'{element_separator.join(elements)}'
+                f'{container_separator}{prefix}]'
+            )
+        elif self.type in (DataElement.UNSIGNED_INTEGER, DataElement.SIGNED_INTEGER):
             value_string = f'{self.value}#{self.value_size}'
         elif isinstance(self.value, DataElement):
             value_string = self.value.to_string(pretty, indentation)
@@ -410,17 +457,17 @@ class DataElement:
 
 # -----------------------------------------------------------------------------
 class ServiceAttribute:
-    def __init__(self, id, value):
-        self.id    = id
+    def __init__(self, attribute_id: int, value: DataElement) -> None:
+        self.id = attribute_id
         self.value = value
 
     @staticmethod
     def list_from_data_elements(elements):
         attribute_list = []
         for i in range(0, len(elements) // 2):
-            attribute_id, attribute_value = elements[2 * i:2 * (i + 1)]
+            attribute_id, attribute_value = elements[2 * i : 2 * (i + 1)]
             if attribute_id.type != DataElement.UNSIGNED_INTEGER:
-                logger.warn('attribute ID element is not an integer')
+                logger.warning('attribute ID element is not an integer')
                 continue
             attribute_list.append(ServiceAttribute(attribute_id.value, attribute_value))
 
@@ -428,30 +475,41 @@ class ServiceAttribute:
 
     @staticmethod
     def find_attribute_in_list(attribute_list, attribute_id):
-        return next((attribute.value for attribute in attribute_list if attribute.id == attribute_id), None)
+        return next(
+            (
+                attribute.value
+                for attribute in attribute_list
+                if attribute.id == attribute_id
+            ),
+            None,
+        )
 
     @staticmethod
-    def id_name(id):
-        return name_or_number(SDP_ATTRIBUTE_ID_NAMES, id)
+    def id_name(id_code):
+        return name_or_number(SDP_ATTRIBUTE_ID_NAMES, id_code)
 
     @staticmethod
     def is_uuid_in_value(uuid, value):
         # Find if a uuid matches a value, either directly or recursing into sequences
         if value.type == DataElement.UUID:
             return value.value == uuid
-        elif value.type == DataElement.SEQUENCE:
+
+        if value.type == DataElement.SEQUENCE:
             for element in value.value:
                 if ServiceAttribute.is_uuid_in_value(uuid, element):
                     return True
             return False
-        else:
-            return False
 
-    def to_string(self, color=False):
-        if color:
-            return f'Attribute(id={colors.color(self.id_name(self.id),"magenta")},value={self.value})'
-        else:
-            return f'Attribute(id={self.id_name(self.id)},value={self.value})'
+        return False
+
+    def to_string(self, with_colors=False):
+        if with_colors:
+            return (
+                f'Attribute(id={color(self.id_name(self.id),"magenta")},'
+                f'value={self.value})'
+            )
+
+        return f'Attribute(id={self.id_name(self.id)},value={self.value})'
 
     def __str__(self):
         return self.to_string()
@@ -462,11 +520,14 @@ class SDP_PDU:
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.2 PROTOCOL DATA UNIT FORMAT
     '''
-    sdp_pdu_classes = {}
+
+    sdp_pdu_classes: Dict[int, Type[SDP_PDU]] = {}
+    name = None
+    pdu_id = 0
 
     @staticmethod
     def from_bytes(pdu):
-        pdu_id, transaction_id, parameters_length = struct.unpack_from('>BHH', pdu, 0)
+        pdu_id, transaction_id, _parameters_length = struct.unpack_from('>BHH', pdu, 0)
 
         cls = SDP_PDU.sdp_pdu_classes.get(pdu_id)
         if cls is None:
@@ -484,13 +545,15 @@ class SDP_PDU:
     @staticmethod
     def parse_service_record_handle_list_preceded_by_count(data, offset):
         count = struct.unpack_from('>H', data, offset - 2)[0]
-        handle_list = [struct.unpack_from('>I', data, offset + x * 4)[0] for x in range(count)]
+        handle_list = [
+            struct.unpack_from('>I', data, offset + x * 4)[0] for x in range(count)
+        ]
         return offset + count * 4, handle_list
 
     @staticmethod
     def parse_bytes_preceded_by_length(data, offset):
         length = struct.unpack_from('>H', data, offset - 2)[0]
-        return offset + length, data[offset:offset + length]
+        return offset + length, data[offset : offset + length]
 
     @staticmethod
     def error_name(error_code):
@@ -532,7 +595,10 @@ class SDP_PDU:
             HCI_Object.init_from_fields(self, self.fields, kwargs)
         if pdu is None:
             parameters = HCI_Object.dict_to_bytes(kwargs, self.fields)
-            pdu = struct.pack('>BHH', self.pdu_id, transaction_id, len(parameters)) + parameters
+            pdu = (
+                struct.pack('>BHH', self.pdu_id, transaction_id, len(parameters))
+                + parameters
+            )
         self.pdu = pdu
         self.transaction_id = transaction_id
 
@@ -555,9 +621,7 @@ class SDP_PDU:
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('error_code', {'size': 2, 'mapper': SDP_PDU.error_name})
-])
+@SDP_PDU.subclass([('error_code', {'size': 2, 'mapper': SDP_PDU.error_name})])
 class SDP_ErrorResponse(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.4.1 SDP_ErrorResponse PDU
@@ -565,11 +629,13 @@ class SDP_ErrorResponse(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('service_search_pattern',       DataElement.parse_from_bytes),
-    ('maximum_service_record_count', '>2'),
-    ('continuation_state',          '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('service_search_pattern', DataElement.parse_from_bytes),
+        ('maximum_service_record_count', '>2'),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceSearchRequest(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.5.1 SDP_ServiceSearchRequest PDU
@@ -577,12 +643,17 @@ class SDP_ServiceSearchRequest(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('total_service_record_count',   '>2'),
-    ('current_service_record_count', '>2'),
-    ('service_record_handle_list',   SDP_PDU.parse_service_record_handle_list_preceded_by_count),
-    ('continuation_state',           '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('total_service_record_count', '>2'),
+        ('current_service_record_count', '>2'),
+        (
+            'service_record_handle_list',
+            SDP_PDU.parse_service_record_handle_list_preceded_by_count,
+        ),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceSearchResponse(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.5.2 SDP_ServiceSearchResponse PDU
@@ -590,12 +661,14 @@ class SDP_ServiceSearchResponse(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('service_record_handle',        '>4'),
-    ('maximum_attribute_byte_count', '>2'),
-    ('attribute_id_list',            DataElement.parse_from_bytes),
-    ('continuation_state',           '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('service_record_handle', '>4'),
+        ('maximum_attribute_byte_count', '>2'),
+        ('attribute_id_list', DataElement.parse_from_bytes),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceAttributeRequest(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.6.1 SDP_ServiceAttributeRequest PDU
@@ -603,11 +676,13 @@ class SDP_ServiceAttributeRequest(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('attribute_list_byte_count', '>2'),
-    ('attribute_list',            SDP_PDU.parse_bytes_preceded_by_length),
-    ('continuation_state',        '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('attribute_list_byte_count', '>2'),
+        ('attribute_list', SDP_PDU.parse_bytes_preceded_by_length),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceAttributeResponse(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.6.2 SDP_ServiceAttributeResponse PDU
@@ -615,12 +690,14 @@ class SDP_ServiceAttributeResponse(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('service_search_pattern',       DataElement.parse_from_bytes),
-    ('maximum_attribute_byte_count', '>2'),
-    ('attribute_id_list',            DataElement.parse_from_bytes),
-    ('continuation_state',          '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('service_search_pattern', DataElement.parse_from_bytes),
+        ('maximum_attribute_byte_count', '>2'),
+        ('attribute_id_list', DataElement.parse_from_bytes),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceSearchAttributeRequest(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.7.1 SDP_ServiceSearchAttributeRequest PDU
@@ -628,11 +705,13 @@ class SDP_ServiceSearchAttributeRequest(SDP_PDU):
 
 
 # -----------------------------------------------------------------------------
-@SDP_PDU.subclass([
-    ('attribute_lists_byte_count', '>2'),
-    ('attribute_lists',            SDP_PDU.parse_bytes_preceded_by_length),
-    ('continuation_state',        '*')
-])
+@SDP_PDU.subclass(
+    [
+        ('attribute_lists_byte_count', '>2'),
+        ('attribute_lists', SDP_PDU.parse_bytes_preceded_by_length),
+        ('continuation_state', '*'),
+    ]
+)
 class SDP_ServiceSearchAttributeResponse(SDP_PDU):
     '''
     See Bluetooth spec @ Vol 3, Part B - 4.7.2 SDP_ServiceSearchAttributeResponse PDU
@@ -642,9 +721,9 @@ class SDP_ServiceSearchAttributeResponse(SDP_PDU):
 # -----------------------------------------------------------------------------
 class Client:
     def __init__(self, device):
-        self.device          = device
+        self.device = device
         self.pending_request = None
-        self.channel         = None
+        self.channel = None
 
     async def connect(self, connection):
         result = await self.device.l2cap_channel_manager.connect(connection, SDP_PSM)
@@ -659,7 +738,9 @@ class Client:
         if self.pending_request is not None:
             raise InvalidStateError('request already pending')
 
-        service_search_pattern = DataElement.sequence([DataElement.uuid(uuid) for uuid in uuids])
+        service_search_pattern = DataElement.sequence(
+            [DataElement.uuid(uuid) for uuid in uuids]
+        )
 
         # Request and accumulate until there's no more continuation
         service_record_handle_list = []
@@ -668,10 +749,10 @@ class Client:
         while watchdog > 0:
             response_pdu = await self.channel.send_request(
                 SDP_ServiceSearchRequest(
-                    transaction_id               = 0,  # Transaction ID TODO: pick a real value
-                    service_search_pattern       = service_search_pattern,
-                    maximum_service_record_count = 0xFFFF,
-                    continuation_state           = continuation_state
+                    transaction_id=0,  # Transaction ID TODO: pick a real value
+                    service_search_pattern=service_search_pattern,
+                    maximum_service_record_count=0xFFFF,
+                    continuation_state=continuation_state,
                 )
             )
             response = SDP_PDU.from_bytes(response_pdu)
@@ -689,11 +770,15 @@ class Client:
         if self.pending_request is not None:
             raise InvalidStateError('request already pending')
 
-        service_search_pattern = DataElement.sequence([DataElement.uuid(uuid) for uuid in uuids])
+        service_search_pattern = DataElement.sequence(
+            [DataElement.uuid(uuid) for uuid in uuids]
+        )
         attribute_id_list = DataElement.sequence(
             [
-                DataElement.unsigned_integer(attribute_id[0], value_size=attribute_id[1])
-                if type(attribute_id) is tuple
+                DataElement.unsigned_integer(
+                    attribute_id[0], value_size=attribute_id[1]
+                )
+                if isinstance(attribute_id, tuple)
                 else DataElement.unsigned_integer_16(attribute_id)
                 for attribute_id in attribute_ids
             ]
@@ -706,11 +791,11 @@ class Client:
         while watchdog > 0:
             response_pdu = await self.channel.send_request(
                 SDP_ServiceSearchAttributeRequest(
-                    transaction_id               = 0,  # Transaction ID TODO: pick a real value
-                    service_search_pattern       = service_search_pattern,
-                    maximum_attribute_byte_count = 0xFFFF,
-                    attribute_id_list            = attribute_id_list,
-                    continuation_state           = continuation_state
+                    transaction_id=0,  # Transaction ID TODO: pick a real value
+                    service_search_pattern=service_search_pattern,
+                    maximum_attribute_byte_count=0xFFFF,
+                    attribute_id_list=attribute_id_list,
+                    continuation_state=continuation_state,
                 )
             )
             response = SDP_PDU.from_bytes(response_pdu)
@@ -725,7 +810,7 @@ class Client:
         # Parse the result into attribute lists
         attribute_lists_sequences = DataElement.from_bytes(accumulator)
         if attribute_lists_sequences.type != DataElement.SEQUENCE:
-            logger.warn('unexpected data type')
+            logger.warning('unexpected data type')
             return []
 
         return [
@@ -740,8 +825,10 @@ class Client:
 
         attribute_id_list = DataElement.sequence(
             [
-                DataElement.unsigned_integer(attribute_id[0], value_size=attribute_id[1])
-                if type(attribute_id) is tuple
+                DataElement.unsigned_integer(
+                    attribute_id[0], value_size=attribute_id[1]
+                )
+                if isinstance(attribute_id, tuple)
                 else DataElement.unsigned_integer_16(attribute_id)
                 for attribute_id in attribute_ids
             ]
@@ -754,11 +841,11 @@ class Client:
         while watchdog > 0:
             response_pdu = await self.channel.send_request(
                 SDP_ServiceAttributeRequest(
-                    transaction_id               = 0,  # Transaction ID TODO: pick a real value
-                    service_record_handle        = service_record_handle,
-                    maximum_attribute_byte_count = 0xFFFF,
-                    attribute_id_list            = attribute_id_list,
-                    continuation_state           = continuation_state
+                    transaction_id=0,  # Transaction ID TODO: pick a real value
+                    service_record_handle=service_record_handle,
+                    maximum_attribute_byte_count=0xFFFF,
+                    attribute_id_list=attribute_id_list,
+                    continuation_state=continuation_state,
                 )
             )
             response = SDP_PDU.from_bytes(response_pdu)
@@ -773,7 +860,7 @@ class Client:
         # Parse the result into a list of attributes
         attribute_list_sequence = DataElement.from_bytes(accumulator)
         if attribute_list_sequence.type != DataElement.SEQUENCE:
-            logger.warn('unexpected data type')
+            logger.warning('unexpected data type')
             return []
 
         return ServiceAttribute.list_from_data_elements(attribute_list_sequence.value)
@@ -784,8 +871,9 @@ class Server:
     CONTINUATION_STATE = bytes([0x01, 0x43])
 
     def __init__(self, device):
-        self.device           = device
-        self.service_records  = {}  # Service records maps, by record handle
+        self.device = device
+        self.service_records = {}  # Service records maps, by record handle
+        self.channel = None
         self.current_response = None
 
     def register(self, l2cap_channel_manager):
@@ -820,11 +908,10 @@ class Server:
         try:
             sdp_pdu = SDP_PDU.from_bytes(pdu)
         except Exception as error:
-            logger.warn(color(f'failed to parse SDP Request PDU: {error}', 'red'))
+            logger.warning(color(f'failed to parse SDP Request PDU: {error}', 'red'))
             self.send_response(
                 SDP_ErrorResponse(
-                    transaction_id = 0,
-                    error_code     = SDP_INVALID_REQUEST_SYNTAX_ERROR
+                    transaction_id=0, error_code=SDP_INVALID_REQUEST_SYNTAX_ERROR
                 )
             )
 
@@ -840,16 +927,16 @@ class Server:
                 logger.warning(f'{color("!!! Exception in handler:", "red")} {error}')
                 self.send_response(
                     SDP_ErrorResponse(
-                        transaction_id = sdp_pdu.transaction_id,
-                        error_code     = SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR
+                        transaction_id=sdp_pdu.transaction_id,
+                        error_code=SDP_INSUFFICIENT_RESOURCES_TO_SATISFY_REQUEST_ERROR,
                     )
                 )
         else:
             logger.error(color('SDP Request not handled???', 'red'))
             self.send_response(
                 SDP_ErrorResponse(
-                    transaction_id = sdp_pdu.transaction_id,
-                    error_code     = SDP_INVALID_REQUEST_SYNTAX_ERROR
+                    transaction_id=sdp_pdu.transaction_id,
+                    error_code=SDP_INVALID_REQUEST_SYNTAX_ERROR,
                 )
             )
 
@@ -872,17 +959,18 @@ class Server:
             if attribute_id.value_size == 4:
                 # Attribute ID range
                 id_range_start = attribute_id.value >> 16
-                id_range_end   = attribute_id.value & 0xFFFF
+                id_range_end = attribute_id.value & 0xFFFF
             else:
                 id_range_start = attribute_id.value
-                id_range_end   = attribute_id.value
+                id_range_end = attribute_id.value
             attributes += [
-                attribute for attribute in service
+                attribute
+                for attribute in service
                 if attribute.id >= id_range_start and attribute.id <= id_range_end
             ]
 
-        # Return the maching attributes, sorted by attribute id
-        attributes.sort(key = lambda x: x.id)
+        # Return the matching attributes, sorted by attribute id
+        attributes.sort(key=lambda x: x.id)
         attribute_list = DataElement.sequence([])
         for attribute in attributes:
             attribute_list.value.append(DataElement.unsigned_integer_16(attribute.id))
@@ -896,8 +984,8 @@ class Server:
             if not self.current_response:
                 self.send_response(
                     SDP_ErrorResponse(
-                        transaction_id = request.transaction_id,
-                        error_code     = SDP_INVALID_CONTINUATION_STATE_ERROR
+                        transaction_id=request.transaction_id,
+                        error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
                     )
                 )
                 return
@@ -910,30 +998,38 @@ class Server:
             service_record_handles = list(matching_services.keys())
 
             # Only return up to the maximum requested
-            service_record_handles_subset = service_record_handles[:request.maximum_service_record_count]
+            service_record_handles_subset = service_record_handles[
+                : request.maximum_service_record_count
+            ]
 
             # Serialize to a byte array, and remember the total count
             logger.debug(f'Service Record Handles: {service_record_handles}')
             self.current_response = (
                 len(service_record_handles),
-                service_record_handles_subset
+                service_record_handles_subset,
             )
 
         # Respond, keeping any unsent handles for later
-        service_record_handles = self.current_response[1][:request.maximum_service_record_count]
+        service_record_handles = self.current_response[1][
+            : request.maximum_service_record_count
+        ]
         self.current_response = (
             self.current_response[0],
-            self.current_response[1][request.maximum_service_record_count:]
+            self.current_response[1][request.maximum_service_record_count :],
+        )
+        continuation_state = (
+            Server.CONTINUATION_STATE if self.current_response[1] else bytes([0])
+        )
+        service_record_handle_list = b''.join(
+            [struct.pack('>I', handle) for handle in service_record_handles]
         )
-        continuation_state = Server.CONTINUATION_STATE if self.current_response[1] else bytes([0])
-        service_record_handle_list = b''.join([struct.pack('>I', handle) for handle in service_record_handles])
         self.send_response(
             SDP_ServiceSearchResponse(
-                transaction_id               = request.transaction_id,
-                total_service_record_count   = self.current_response[0],
-                current_service_record_count = len(service_record_handles),
-                service_record_handle_list   = service_record_handle_list,
-                continuation_state           = continuation_state
+                transaction_id=request.transaction_id,
+                total_service_record_count=self.current_response[0],
+                current_service_record_count=len(service_record_handles),
+                service_record_handle_list=service_record_handle_list,
+                continuation_state=continuation_state,
             )
         )
 
@@ -943,8 +1039,8 @@ class Server:
             if not self.current_response:
                 self.send_response(
                     SDP_ErrorResponse(
-                        transaction_id = request.transaction_id,
-                        error_code     = SDP_INVALID_CONTINUATION_STATE_ERROR
+                        transaction_id=request.transaction_id,
+                        error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
                     )
                 )
                 return
@@ -957,27 +1053,31 @@ class Server:
             if service is None:
                 self.send_response(
                     SDP_ErrorResponse(
-                        transaction_id = request.transaction_id,
-                        error_code     = SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR
+                        transaction_id=request.transaction_id,
+                        error_code=SDP_INVALID_SERVICE_RECORD_HANDLE_ERROR,
                     )
                 )
                 return
 
             # Get the attributes for the service
-            attribute_list = Server.get_service_attributes(service, request.attribute_id_list.value)
+            attribute_list = Server.get_service_attributes(
+                service, request.attribute_id_list.value
+            )
 
             # Serialize to a byte array
             logger.debug(f'Attributes: {attribute_list}')
             self.current_response = bytes(attribute_list)
 
         # Respond, keeping any pending chunks for later
-        attribute_list, continuation_state = self.get_next_response_payload(request.maximum_attribute_byte_count)
+        attribute_list, continuation_state = self.get_next_response_payload(
+            request.maximum_attribute_byte_count
+        )
         self.send_response(
             SDP_ServiceAttributeResponse(
-                transaction_id            = request.transaction_id,
-                attribute_list_byte_count = len(attribute_list),
-                attribute_list            = attribute_list,
-                continuation_state        = continuation_state
+                transaction_id=request.transaction_id,
+                attribute_list_byte_count=len(attribute_list),
+                attribute_list=attribute_list,
+                continuation_state=continuation_state,
             )
         )
 
@@ -987,8 +1087,8 @@ class Server:
             if not self.current_response:
                 self.send_response(
                     SDP_ErrorResponse(
-                        transaction_id = request.transaction_id,
-                        error_code     = SDP_INVALID_CONTINUATION_STATE_ERROR
+                        transaction_id=request.transaction_id,
+                        error_code=SDP_INVALID_CONTINUATION_STATE_ERROR,
                     )
                 )
         else:
@@ -996,12 +1096,16 @@ class Server:
             self.current_response = None
 
             # Find the matching services
-            matching_services = self.match_services(request.service_search_pattern).values()
+            matching_services = self.match_services(
+                request.service_search_pattern
+            ).values()
 
             # Filter the required attributes
             attribute_lists = DataElement.sequence([])
             for service in matching_services:
-                attribute_list = Server.get_service_attributes(service, request.attribute_id_list.value)
+                attribute_list = Server.get_service_attributes(
+                    service, request.attribute_id_list.value
+                )
                 if attribute_list.value:
                     attribute_lists.value.append(attribute_list)
 
@@ -1010,12 +1114,14 @@ class Server:
             self.current_response = bytes(attribute_lists)
 
         # Respond, keeping any pending chunks for later
-        attribute_lists, continuation_state = self.get_next_response_payload(request.maximum_attribute_byte_count)
+        attribute_lists, continuation_state = self.get_next_response_payload(
+            request.maximum_attribute_byte_count
+        )
         self.send_response(
             SDP_ServiceSearchAttributeResponse(
-                transaction_id             = request.transaction_id,
-                attribute_lists_byte_count = len(attribute_lists),
-                attribute_lists            = attribute_lists,
-                continuation_state         = continuation_state
+                transaction_id=request.transaction_id,
+                attribute_lists_byte_count=len(attribute_lists),
+                attribute_lists=attribute_lists,
+                continuation_state=continuation_state,
             )
         )

bumble/snoop.py

@@ -0,0 +1,170 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+from contextlib import contextmanager
+from enum import IntEnum
+import logging
+import struct
+import datetime
+from typing import BinaryIO, Generator
+import os
+
+from bumble.hci import HCI_COMMAND_PACKET, HCI_EVENT_PACKET
+
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Classes
+# -----------------------------------------------------------------------------
+class Snooper:
+    """
+    Base class for snooper implementations.
+
+    A snooper is an object that will be provided with HCI packets as they are
+    exchanged between a host and a controller.
+    """
+
+    class Direction(IntEnum):
+        HOST_TO_CONTROLLER = 0
+        CONTROLLER_TO_HOST = 1
+
+    class DataLinkType(IntEnum):
+        H1 = 1001
+        H4 = 1002
+        HCI_BSCP = 1003
+        H5 = 1004
+
+    def snoop(self, hci_packet: bytes, direction: Direction) -> None:
+        """Snoop on an HCI packet."""
+
+
+# -----------------------------------------------------------------------------
+class BtSnooper(Snooper):
+    """
+    Snooper that saves HCI packets using the BTSnoop format, based on RFC 1761.
+    """
+
+    IDENTIFICATION_PATTERN = b'btsnoop\0'
+    TIMESTAMP_ANCHOR = datetime.datetime(2000, 1, 1)
+    TIMESTAMP_DELTA = 0x00E03AB44A676000
+    ONE_MS = datetime.timedelta(microseconds=1)
+
+    def __init__(self, output: BinaryIO):
+        self.output = output
+
+        # Write the header
+        self.output.write(
+            self.IDENTIFICATION_PATTERN + struct.pack('>LL', 1, self.DataLinkType.H4)
+        )
+
+    def snoop(self, hci_packet: bytes, direction: Snooper.Direction) -> None:
+        flags = int(direction)
+        packet_type = hci_packet[0]
+        if packet_type in (HCI_EVENT_PACKET, HCI_COMMAND_PACKET):
+            flags |= 0x10
+
+        # Compute the current timestamp
+        timestamp = (
+            int((datetime.datetime.utcnow() - self.TIMESTAMP_ANCHOR) / self.ONE_MS)
+            + self.TIMESTAMP_DELTA
+        )
+
+        # Emit the record
+        self.output.write(
+            struct.pack(
+                '>IIIIQ',
+                len(hci_packet),  # Original Length
+                len(hci_packet),  # Included Length
+                flags,  # Packet Flags
+                0,  # Cumulative Drops
+                timestamp,  # Timestamp
+            )
+            + hci_packet
+        )
+
+
+# -----------------------------------------------------------------------------
+_SNOOPER_INSTANCE_COUNT = 0
+
+
+@contextmanager
+def create_snooper(spec: str) -> Generator[Snooper, None, None]:
+    """
+    Create a snooper given a specification string.
+
+    The general syntax for the specification string is:
+      <snooper-type>:<type-specific-arguments>
+
+    Supported snooper types are:
+
+      btsnoop
+        The syntax for the type-specific arguments for this type is:
+        <io-type>:<io-type-specific-arguments>
+
+        Supported I/O types are:
+
+        file
+          The type-specific arguments for this I/O type is a string that is converted
+          to a file path using the python `str.format()` string formatting. The log
+          records will be written to that file if it can be opened/created.
+          The keyword args that may be referenced by the string pattern are:
+            now: the value of `datetime.now()`
+            utcnow: the value of `datetime.utcnow()`
+            pid: the current process ID.
+            instance: the instance ID in the current process.
+
+    Examples:
+      btsnoop:file:my_btsnoop.log
+      btsnoop:file:/tmp/bumble_{now:%Y-%m-%d-%H:%M:%S}_{pid}.log
+
+    """
+    if ':' not in spec:
+        raise ValueError('snooper type prefix missing')
+
+    snooper_type, snooper_args = spec.split(':', maxsplit=1)
+
+    if snooper_type == 'btsnoop':
+        if ':' not in snooper_args:
+            raise ValueError('I/O type for btsnoop snooper type missing')
+
+        io_type, io_name = snooper_args.split(':', maxsplit=1)
+        if io_type == 'file':
+            # Process the file name string pattern.
+            global _SNOOPER_INSTANCE_COUNT
+            file_path = io_name.format(
+                now=datetime.datetime.now(),
+                utcnow=datetime.datetime.utcnow(),
+                pid=os.getpid(),
+                instance=_SNOOPER_INSTANCE_COUNT,
+            )
+
+            # Open the file
+            logger.debug(f'Snoop file: {file_path}')
+            with open(file_path, 'wb') as snoop_file:
+                _SNOOPER_INSTANCE_COUNT += 1
+                yield BtSnooper(snoop_file)
+                _SNOOPER_INSTANCE_COUNT -= 1
+                return
+
+        raise ValueError(f'I/O type {io_type} not supported')
+
+    raise ValueError(f'snooper type {snooper_type} not found')

bumble/transport/__init__.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,11 +15,13 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from contextlib import asynccontextmanager
 import logging
+import os
 
-from .common import Transport, AsyncPipeSink
-from ..link import RemoteLink
+from .common import Transport, AsyncPipeSink, SnoopingTransport
 from ..controller import Controller
+from ..snoop import create_snooper
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -28,68 +30,148 @@ logger = logging.getLogger(__name__)
 
 
 # -----------------------------------------------------------------------------
-async def open_transport(name):
-    '''
-    Open a transport by name.
-    The name must be <type>:<parameters>
-    Where <parameters> depend on the type (and may be empty for some types).
-    The supported types are: serial,udp,tcp,pty,usb
-    '''
-    scheme, *spec = name.split(':', 1)
-    if scheme == 'serial' and spec:
-        from .serial import open_serial_transport
-        return await open_serial_transport(spec[0])
-    elif scheme == 'udp' and spec:
-        from .udp import open_udp_transport
-        return await open_udp_transport(spec[0])
-    elif scheme == 'tcp-client' and spec:
-        from .tcp_client import open_tcp_client_transport
-        return await open_tcp_client_transport(spec[0])
-    elif scheme == 'tcp-server' and spec:
-        from .tcp_server import open_tcp_server_transport
-        return await open_tcp_server_transport(spec[0])
-    elif scheme == 'ws-client' and spec:
-        from .ws_client import open_ws_client_transport
-        return await open_ws_client_transport(spec[0])
-    elif scheme == 'ws-server' and spec:
-        from .ws_server import open_ws_server_transport
-        return await open_ws_server_transport(spec[0])
-    elif scheme == 'pty':
-        from .pty import open_pty_transport
-        return await open_pty_transport(spec[0] if spec else None)
-    elif scheme == 'file':
-        from .file import open_file_transport
-        return await open_file_transport(spec[0] if spec else None)
-    elif scheme == 'vhci':
-        from .vhci import open_vhci_transport
-        return await open_vhci_transport(spec[0] if spec else None)
-    elif scheme == 'hci-socket':
-        from .hci_socket import open_hci_socket_transport
-        return await open_hci_socket_transport(spec[0] if spec else None)
-    elif scheme == 'usb':
-        from .usb import open_usb_transport
-        return await open_usb_transport(spec[0] if spec else None)
-    elif scheme == 'pyusb':
-        from .pyusb import open_pyusb_transport
-        return await open_pyusb_transport(spec[0] if spec else None)
-    elif scheme == 'android-emulator':
-        from .android_emulator import open_android_emulator_transport
-        return await open_android_emulator_transport(spec[0] if spec else None)
-    else:
-        raise ValueError('unknown transport scheme')
+def _wrap_transport(transport: Transport) -> Transport:
+    """
+    Automatically wrap a Transport instance when a wrapping class can be inferred
+    from the environment.
+    If no wrapping class is applicable, the transport argument is returned as-is.
+    """
+
+    # If BUMBLE_SNOOPER is set, try to automatically create a snooper.
+    if snooper_spec := os.getenv('BUMBLE_SNOOPER'):
+        try:
+            return SnoopingTransport.create_with(
+                transport, create_snooper(snooper_spec)
+            )
+        except Exception as exc:
+            logger.warning(f'Exception while creating snooper: {exc}')
+
+    return transport
 
 
 # -----------------------------------------------------------------------------
-async def open_transport_or_link(name):
+async def open_transport(name: str) -> Transport:
+    """
+    Open a transport by name.
+    The name must be <type>:<parameters>
+    Where <parameters> depend on the type (and may be empty for some types).
+    The supported types are:
+      * serial
+      * udp
+      * tcp-client
+      * tcp-server
+      * ws-client
+      * ws-server
+      * pty
+      * file
+      * vhci
+      * hci-socket
+      * usb
+      * pyusb
+      * android-emulator
+    """
+
+    return _wrap_transport(await _open_transport(name))
+
+
+# -----------------------------------------------------------------------------
+async def _open_transport(name: str) -> Transport:
+    # pylint: disable=import-outside-toplevel
+    # pylint: disable=too-many-return-statements
+
+    scheme, *spec = name.split(':', 1)
+    if scheme == 'serial' and spec:
+        from .serial import open_serial_transport
+
+        return await open_serial_transport(spec[0])
+
+    if scheme == 'udp' and spec:
+        from .udp import open_udp_transport
+
+        return await open_udp_transport(spec[0])
+
+    if scheme == 'tcp-client' and spec:
+        from .tcp_client import open_tcp_client_transport
+
+        return await open_tcp_client_transport(spec[0])
+
+    if scheme == 'tcp-server' and spec:
+        from .tcp_server import open_tcp_server_transport
+
+        return await open_tcp_server_transport(spec[0])
+
+    if scheme == 'ws-client' and spec:
+        from .ws_client import open_ws_client_transport
+
+        return await open_ws_client_transport(spec[0])
+
+    if scheme == 'ws-server' and spec:
+        from .ws_server import open_ws_server_transport
+
+        return await open_ws_server_transport(spec[0])
+
+    if scheme == 'pty':
+        from .pty import open_pty_transport
+
+        return await open_pty_transport(spec[0] if spec else None)
+
+    if scheme == 'file':
+        from .file import open_file_transport
+
+        return await open_file_transport(spec[0] if spec else None)
+
+    if scheme == 'vhci':
+        from .vhci import open_vhci_transport
+
+        return await open_vhci_transport(spec[0] if spec else None)
+
+    if scheme == 'hci-socket':
+        from .hci_socket import open_hci_socket_transport
+
+        return await open_hci_socket_transport(spec[0] if spec else None)
+
+    if scheme == 'usb':
+        from .usb import open_usb_transport
+
+        return await open_usb_transport(spec[0] if spec else None)
+
+    if scheme == 'pyusb':
+        from .pyusb import open_pyusb_transport
+
+        return await open_pyusb_transport(spec[0] if spec else None)
+
+    if scheme == 'android-emulator':
+        from .android_emulator import open_android_emulator_transport
+
+        return await open_android_emulator_transport(spec[0] if spec else None)
+
+    raise ValueError('unknown transport scheme')
+
+
+# -----------------------------------------------------------------------------
+async def open_transport_or_link(name: str) -> Transport:
+    """
+    Open a transport or a link relay.
+
+    Args:
+      name:
+        Name of the transport or link relay to open.
+        When the name starts with "link-relay:", open a link relay (see RemoteLink
+        for details on what the arguments are).
+        For other namespaces, see `open_transport`.
+
+    """
     if name.startswith('link-relay:'):
+        from ..link import RemoteLink  # lazy import
+
         link = RemoteLink(name[11:])
         await link.wait_until_connected()
-        controller = Controller('remote', link = link)
+        controller = Controller('remote', link=link)
 
         class LinkTransport(Transport):
             async def close(self):
                 link.close()
 
-        return LinkTransport(controller, AsyncPipeSink(controller))
-    else:
-        return await open_transport(name)
+        return _wrap_transport(LinkTransport(controller, AsyncPipeSink(controller)))
+
+    return await open_transport(name)

bumble/transport/android_emulator.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -20,9 +20,11 @@ import grpc
 
 from .common import PumpedTransport, PumpedPacketSource, PumpedPacketSink
 from .emulated_bluetooth_pb2_grpc import EmulatedBluetoothServiceStub
-from .emulated_bluetooth_packets_pb2 import HCIPacket
 from .emulated_bluetooth_vhci_pb2_grpc import VhciForwardingServiceStub
 
+# pylint: disable-next=no-name-in-module
+from .emulated_bluetooth_packets_pb2 import HCIPacket
+
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -59,15 +61,10 @@ async def open_android_emulator_transport(spec):
             return bytes([packet.type]) + packet.packet
 
         async def write(self, packet):
-            await self.hci_device.write(
-                HCIPacket(
-                    type   = packet[0],
-                    packet = packet[1:]
-                )
-            )
+            await self.hci_device.write(HCIPacket(type=packet[0], packet=packet[1:]))
 
     # Parse the parameters
-    mode        = 'host'
+    mode = 'host'
     server_host = 'localhost'
     server_port = 8554
     if spec is not None:
@@ -100,7 +97,7 @@ async def open_android_emulator_transport(spec):
     transport = PumpedTransport(
         PumpedPacketSource(hci_device.read),
         PumpedPacketSink(hci_device.write),
-        channel.close
+        channel.close,
     )
     transport.start()
 

bumble/transport/common.py

@@ -15,12 +15,16 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
+import contextlib
 import struct
 import asyncio
 import logging
-from colors import color
+from typing import ContextManager
 
 from .. import hci
+from ..colors import color
+from ..snoop import Snooper
 
 
 # -----------------------------------------------------------------------------
@@ -33,10 +37,10 @@ logger = logging.getLogger(__name__)
 # For each packet type, the info represents:
 # (length-size, length-offset, unpack-type)
 HCI_PACKET_INFO = {
-    hci.HCI_COMMAND_PACKET:          (1, 2, 'B'),
-    hci.HCI_ACL_DATA_PACKET:         (2, 2, 'H'),
+    hci.HCI_COMMAND_PACKET: (1, 2, 'B'),
+    hci.HCI_ACL_DATA_PACKET: (2, 2, 'H'),
     hci.HCI_SYNCHRONOUS_DATA_PACKET: (1, 2, 'B'),
-    hci.HCI_EVENT_PACKET:            (1, 1, 'B')
+    hci.HCI_EVENT_PACKET: (1, 1, 'B'),
 }
 
 
@@ -48,7 +52,7 @@ class PacketPump:
 
     def __init__(self, reader, sink):
         self.reader = reader
-        self.sink   = sink
+        self.sink = sink
 
     async def run(self):
         while True:
@@ -65,43 +69,51 @@ class PacketPump:
 # -----------------------------------------------------------------------------
 class PacketParser:
     '''
-    In-line parser that accepts data and emits 'on_packet' when a full packet has been parsed
+    In-line parser that accepts data and emits 'on_packet' when a full packet has been
+    parsed
     '''
-    NEED_TYPE   = 0
-    NEED_LENGTH = 1
-    NEED_BODY   = 2
 
-    def __init__(self, sink = None):
+    # pylint: disable=attribute-defined-outside-init
+
+    NEED_TYPE = 0
+    NEED_LENGTH = 1
+    NEED_BODY = 2
+
+    def __init__(self, sink=None):
         self.sink = sink
         self.extended_packet_info = {}
         self.reset()
 
     def reset(self):
-        self.state        = PacketParser.NEED_TYPE
+        self.state = PacketParser.NEED_TYPE
         self.bytes_needed = 1
-        self.packet       = bytearray()
-        self.packet_info  = None
+        self.packet = bytearray()
+        self.packet_info = None
 
     def feed_data(self, data):
         data_offset = 0
         data_left = len(data)
         while data_left and self.bytes_needed:
             consumed = min(self.bytes_needed, data_left)
-            self.packet.extend(data[data_offset:data_offset + consumed])
-            data_offset       += consumed
-            data_left         -= consumed
+            self.packet.extend(data[data_offset : data_offset + consumed])
+            data_offset += consumed
+            data_left -= consumed
             self.bytes_needed -= consumed
 
             if self.bytes_needed == 0:
                 if self.state == PacketParser.NEED_TYPE:
                     packet_type = self.packet[0]
-                    self.packet_info  = HCI_PACKET_INFO.get(packet_type) or self.extended_packet_info.get(packet_type)
+                    self.packet_info = HCI_PACKET_INFO.get(
+                        packet_type
+                    ) or self.extended_packet_info.get(packet_type)
                     if self.packet_info is None:
                         raise ValueError(f'invalid packet type {packet_type}')
                     self.state = PacketParser.NEED_LENGTH
                     self.bytes_needed = self.packet_info[0] + self.packet_info[1]
                 elif self.state == PacketParser.NEED_LENGTH:
-                    body_length = struct.unpack_from(self.packet_info[2], self.packet, 1 + self.packet_info[1])[0]
+                    body_length = struct.unpack_from(
+                        self.packet_info[2], self.packet, 1 + self.packet_info[1]
+                    )[0]
                     self.bytes_needed = body_length
                     self.state = PacketParser.NEED_BODY
 
@@ -111,7 +123,9 @@ class PacketParser:
                         try:
                             self.sink.on_packet(bytes(self.packet))
                         except Exception as error:
-                            logger.warning(color(f'!!! Exception in on_packet: {error}', 'red'))
+                            logger.warning(
+                                color(f'!!! Exception in on_packet: {error}', 'red')
+                            )
                     self.reset()
 
     def set_packet_sink(self, sink):
@@ -187,6 +201,7 @@ class AsyncPipeSink:
     '''
     Sink that forwards packets asynchronously to another sink
     '''
+
     def __init__(self, sink):
         self.sink = sink
         self.loop = asyncio.get_running_loop()
@@ -202,7 +217,7 @@ class ParserSource:
     """
 
     def __init__(self):
-        self.parser     = PacketParser()
+        self.parser = PacketParser()
         self.terminated = asyncio.get_running_loop().create_future()
 
     def set_packet_sink(self, sink):
@@ -235,9 +250,23 @@ class StreamPacketSink:
 
 # -----------------------------------------------------------------------------
 class Transport:
+    """
+    Base class for all transports.
+
+    A Transport represents a source and a sink together.
+    An instance must be closed by calling close() when no longer used. Instances
+    implement the ContextManager protocol so that they may be used in a `async with`
+    statement.
+    An instance is iterable. The iterator yields, in order, its source and sink, so
+    that it may be used with a convenient call syntax like:
+
+    async with create_transport() as (source, sink):
+        ...
+    """
+
     def __init__(self, source, sink):
         self.source = source
-        self.sink   = sink
+        self.sink = sink
 
     async def __aenter__(self):
         return self
@@ -248,7 +277,7 @@ class Transport:
     def __iter__(self):
         return iter((self.source, self.sink))
 
-    async def close(self):
+    async def close(self) -> None:
         self.source.close()
         self.sink.close()
 
@@ -258,7 +287,7 @@ class PumpedPacketSource(ParserSource):
     def __init__(self, receive):
         super().__init__()
         self.receive_function = receive
-        self.pump_task        = None
+        self.pump_task = None
 
     def start(self):
         async def pump_packets():
@@ -270,11 +299,11 @@ class PumpedPacketSource(ParserSource):
                     logger.debug('source pump task done')
                     break
                 except Exception as error:
-                    logger.warn(f'exception while waiting for packet: {error}')
+                    logger.warning(f'exception while waiting for packet: {error}')
                     self.terminated.set_result(error)
                     break
 
-        self.pump_task = asyncio.get_running_loop().create_task(pump_packets())
+        self.pump_task = asyncio.create_task(pump_packets())
 
     def close(self):
         if self.pump_task:
@@ -285,8 +314,8 @@ class PumpedPacketSource(ParserSource):
 class PumpedPacketSink:
     def __init__(self, send):
         self.send_function = send
-        self.packet_queue  = asyncio.Queue()
-        self.pump_task     = None
+        self.packet_queue = asyncio.Queue()
+        self.pump_task = None
 
     def on_packet(self, packet):
         self.packet_queue.put_nowait(packet)
@@ -301,10 +330,10 @@ class PumpedPacketSink:
                     logger.debug('sink pump task done')
                     break
                 except Exception as error:
-                    logger.warn(f'exception while sending packet: {error}')
+                    logger.warning(f'exception while sending packet: {error}')
                     break
 
-        self.pump_task = asyncio.get_running_loop().create_task(pump_packets())
+        self.pump_task = asyncio.create_task(pump_packets())
 
     def close(self):
         if self.pump_task:
@@ -324,3 +353,60 @@ class PumpedTransport(Transport):
     async def close(self):
         await super().close()
         await self.close_function()
+
+
+# -----------------------------------------------------------------------------
+class SnoopingTransport(Transport):
+    """Transport wrapper that snoops on packets to/from a wrapped transport."""
+
+    @staticmethod
+    def create_with(
+        transport: Transport, snooper: ContextManager[Snooper]
+    ) -> SnoopingTransport:
+        """
+        Create an instance given a snooper that works as as context manager.
+
+        The returned instance will exit the snooper context when it is closed.
+        """
+        with contextlib.ExitStack() as exit_stack:
+            return SnoopingTransport(
+                transport, exit_stack.enter_context(snooper), exit_stack.pop_all().close
+            )
+        raise RuntimeError('unexpected code path')  # Satisfy the type checker
+
+    class Source:
+        def __init__(self, source, snooper):
+            self.source = source
+            self.snooper = snooper
+            self.sink = None
+
+        def set_packet_sink(self, sink):
+            self.sink = sink
+            self.source.set_packet_sink(self)
+
+        def on_packet(self, packet):
+            self.snooper.snoop(packet, Snooper.Direction.CONTROLLER_TO_HOST)
+            if self.sink:
+                self.sink.on_packet(packet)
+
+    class Sink:
+        def __init__(self, sink, snooper):
+            self.sink = sink
+            self.snooper = snooper
+
+        def on_packet(self, packet):
+            self.snooper.snoop(packet, Snooper.Direction.HOST_TO_CONTROLLER)
+            if self.sink:
+                self.sink.on_packet(packet)
+
+    def __init__(self, transport, snooper, close_snooper=None):
+        super().__init__(
+            self.Source(transport.source, snooper), self.Sink(transport.sink, snooper)
+        )
+        self.transport = transport
+        self.close_snooper = close_snooper
+
+    async def close(self):
+        await self.transport.close()
+        if self.close_snooper:
+            self.close_snooper()

bumble/transport/emulated_bluetooth_packets_pb2.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,37 +16,30 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # source: emulated_bluetooth_packets.proto
 """Generated protocol buffer code."""
+from google.protobuf.internal import builder as _builder
 from google.protobuf import descriptor as _descriptor
 from google.protobuf import descriptor_pool as _descriptor_pool
-from google.protobuf import message as _message
-from google.protobuf import reflection as _reflection
 from google.protobuf import symbol_database as _symbol_database
+
 # @@protoc_insertion_point(imports)
 
 _sym_db = _symbol_database.Default()
 
 
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(
+    b'\n emulated_bluetooth_packets.proto\x12\x1b\x61ndroid.emulation.bluetooth\"\xfb\x01\n\tHCIPacket\x12?\n\x04type\x18\x01 \x01(\x0e\x32\x31.android.emulation.bluetooth.HCIPacket.PacketType\x12\x0e\n\x06packet\x18\x02 \x01(\x0c\"\x9c\x01\n\nPacketType\x12\x1b\n\x17PACKET_TYPE_UNSPECIFIED\x10\x00\x12\x1b\n\x17PACKET_TYPE_HCI_COMMAND\x10\x01\x12\x13\n\x0fPACKET_TYPE_ACL\x10\x02\x12\x13\n\x0fPACKET_TYPE_SCO\x10\x03\x12\x15\n\x11PACKET_TYPE_EVENT\x10\x04\x12\x13\n\x0fPACKET_TYPE_ISO\x10\x05\x42J\n\x1f\x63om.android.emulation.bluetoothP\x01\xf8\x01\x01\xa2\x02\x03\x41\x45\x42\xaa\x02\x1b\x41ndroid.Emulation.Bluetoothb\x06proto3'
+)
 
-
-DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n emulated_bluetooth_packets.proto\x12\x1b\x61ndroid.emulation.bluetooth\"\xfb\x01\n\tHCIPacket\x12?\n\x04type\x18\x01 \x01(\x0e\x32\x31.android.emulation.bluetooth.HCIPacket.PacketType\x12\x0e\n\x06packet\x18\x02 \x01(\x0c\"\x9c\x01\n\nPacketType\x12\x1b\n\x17PACKET_TYPE_UNSPECIFIED\x10\x00\x12\x1b\n\x17PACKET_TYPE_HCI_COMMAND\x10\x01\x12\x13\n\x0fPACKET_TYPE_ACL\x10\x02\x12\x13\n\x0fPACKET_TYPE_SCO\x10\x03\x12\x15\n\x11PACKET_TYPE_EVENT\x10\x04\x12\x13\n\x0fPACKET_TYPE_ISO\x10\x05\x42J\n\x1f\x63om.android.emulation.bluetoothP\x01\xf8\x01\x01\xa2\x02\x03\x41\x45\x42\xaa\x02\x1b\x41ndroid.Emulation.Bluetoothb\x06proto3')
-
-
-
-_HCIPACKET = DESCRIPTOR.message_types_by_name['HCIPacket']
-_HCIPACKET_PACKETTYPE = _HCIPACKET.enum_types_by_name['PacketType']
-HCIPacket = _reflection.GeneratedProtocolMessageType('HCIPacket', (_message.Message,), {
-  'DESCRIPTOR' : _HCIPACKET,
-  '__module__' : 'emulated_bluetooth_packets_pb2'
-  # @@protoc_insertion_point(class_scope:android.emulation.bluetooth.HCIPacket)
-  })
-_sym_db.RegisterMessage(HCIPacket)
-
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
+_builder.BuildTopDescriptorsAndMessages(
+    DESCRIPTOR, 'emulated_bluetooth_packets_pb2', globals()
+)
 if _descriptor._USE_C_DESCRIPTORS == False:
 
-  DESCRIPTOR._options = None
-  DESCRIPTOR._serialized_options = b'\n\037com.android.emulation.bluetoothP\001\370\001\001\242\002\003AEB\252\002\033Android.Emulation.Bluetooth'
-  _HCIPACKET._serialized_start=66
-  _HCIPACKET._serialized_end=317
-  _HCIPACKET_PACKETTYPE._serialized_start=161
-  _HCIPACKET_PACKETTYPE._serialized_end=317
+    DESCRIPTOR._options = None
+    DESCRIPTOR._serialized_options = b'\n\037com.android.emulation.bluetoothP\001\370\001\001\242\002\003AEB\252\002\033Android.Emulation.Bluetooth'
+    _HCIPACKET._serialized_start = 66
+    _HCIPACKET._serialized_end = 317
+    _HCIPACKET_PACKETTYPE._serialized_start = 161
+    _HCIPACKET_PACKETTYPE._serialized_end = 317
 # @@protoc_insertion_point(module_scope)

bumble/transport/emulated_bluetooth_packets_pb2.pyi

@@ -0,0 +1,41 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from google.protobuf.internal import enum_type_wrapper as _enum_type_wrapper
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Optional as _Optional, Union as _Union
+
+DESCRIPTOR: _descriptor.FileDescriptor
+
+class HCIPacket(_message.Message):
+    __slots__ = ["packet", "type"]
+
+    class PacketType(int, metaclass=_enum_type_wrapper.EnumTypeWrapper):
+        __slots__ = []
+    PACKET_FIELD_NUMBER: _ClassVar[int]
+    PACKET_TYPE_ACL: HCIPacket.PacketType
+    PACKET_TYPE_EVENT: HCIPacket.PacketType
+    PACKET_TYPE_HCI_COMMAND: HCIPacket.PacketType
+    PACKET_TYPE_ISO: HCIPacket.PacketType
+    PACKET_TYPE_SCO: HCIPacket.PacketType
+    PACKET_TYPE_UNSPECIFIED: HCIPacket.PacketType
+    TYPE_FIELD_NUMBER: _ClassVar[int]
+    packet: bytes
+    type: HCIPacket.PacketType
+    def __init__(
+        self,
+        type: _Optional[_Union[HCIPacket.PacketType, str]] = ...,
+        packet: _Optional[bytes] = ...,
+    ) -> None: ...

bumble/transport/emulated_bluetooth_packets_pb2_grpc.py

@@ -0,0 +1,17 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+"""Client and server classes corresponding to protobuf-defined services."""
+import grpc

bumble/transport/emulated_bluetooth_pb2.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,11 +16,11 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # source: emulated_bluetooth.proto
 """Generated protocol buffer code."""
+from google.protobuf.internal import builder as _builder
 from google.protobuf import descriptor as _descriptor
 from google.protobuf import descriptor_pool as _descriptor_pool
-from google.protobuf import message as _message
-from google.protobuf import reflection as _reflection
 from google.protobuf import symbol_database as _symbol_database
+
 # @@protoc_insertion_point(imports)
 
 _sym_db = _symbol_database.Default()
@@ -29,25 +29,18 @@ _sym_db = _symbol_database.Default()
 from . import emulated_bluetooth_packets_pb2 as emulated__bluetooth__packets__pb2
 
 
-DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x18\x65mulated_bluetooth.proto\x12\x1b\x61ndroid.emulation.bluetooth\x1a emulated_bluetooth_packets.proto\"\x19\n\x07RawData\x12\x0e\n\x06packet\x18\x01 \x01(\x0c\x32\xcb\x02\n\x18\x45mulatedBluetoothService\x12\x64\n\x12registerClassicPhy\x12$.android.emulation.bluetooth.RawData\x1a$.android.emulation.bluetooth.RawData(\x01\x30\x01\x12`\n\x0eregisterBlePhy\x12$.android.emulation.bluetooth.RawData\x1a$.android.emulation.bluetooth.RawData(\x01\x30\x01\x12g\n\x11registerHCIDevice\x12&.android.emulation.bluetooth.HCIPacket\x1a&.android.emulation.bluetooth.HCIPacket(\x01\x30\x01\x42\"\n\x1e\x63om.android.emulator.bluetoothP\x01\x62\x06proto3')
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(
+    b'\n\x18\x65mulated_bluetooth.proto\x12\x1b\x61ndroid.emulation.bluetooth\x1a emulated_bluetooth_packets.proto\"\x19\n\x07RawData\x12\x0e\n\x06packet\x18\x01 \x01(\x0c\x32\xcb\x02\n\x18\x45mulatedBluetoothService\x12\x64\n\x12registerClassicPhy\x12$.android.emulation.bluetooth.RawData\x1a$.android.emulation.bluetooth.RawData(\x01\x30\x01\x12`\n\x0eregisterBlePhy\x12$.android.emulation.bluetooth.RawData\x1a$.android.emulation.bluetooth.RawData(\x01\x30\x01\x12g\n\x11registerHCIDevice\x12&.android.emulation.bluetooth.HCIPacket\x1a&.android.emulation.bluetooth.HCIPacket(\x01\x30\x01\x42\"\n\x1e\x63om.android.emulator.bluetoothP\x01\x62\x06proto3'
+)
 
-
-
-_RAWDATA = DESCRIPTOR.message_types_by_name['RawData']
-RawData = _reflection.GeneratedProtocolMessageType('RawData', (_message.Message,), {
-  'DESCRIPTOR' : _RAWDATA,
-  '__module__' : 'emulated_bluetooth_pb2'
-  # @@protoc_insertion_point(class_scope:android.emulation.bluetooth.RawData)
-  })
-_sym_db.RegisterMessage(RawData)
-
-_EMULATEDBLUETOOTHSERVICE = DESCRIPTOR.services_by_name['EmulatedBluetoothService']
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'emulated_bluetooth_pb2', globals())
 if _descriptor._USE_C_DESCRIPTORS == False:
 
-  DESCRIPTOR._options = None
-  DESCRIPTOR._serialized_options = b'\n\036com.android.emulator.bluetoothP\001'
-  _RAWDATA._serialized_start=91
-  _RAWDATA._serialized_end=116
-  _EMULATEDBLUETOOTHSERVICE._serialized_start=119
-  _EMULATEDBLUETOOTHSERVICE._serialized_end=450
+    DESCRIPTOR._options = None
+    DESCRIPTOR._serialized_options = b'\n\036com.android.emulator.bluetoothP\001'
+    _RAWDATA._serialized_start = 91
+    _RAWDATA._serialized_end = 116
+    _EMULATEDBLUETOOTHSERVICE._serialized_start = 119
+    _EMULATEDBLUETOOTHSERVICE._serialized_end = 450
 # @@protoc_insertion_point(module_scope)

bumble/transport/emulated_bluetooth_pb2.pyi

@@ -0,0 +1,26 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import emulated_bluetooth_packets_pb2 as _emulated_bluetooth_packets_pb2
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Optional as _Optional
+
+DESCRIPTOR: _descriptor.FileDescriptor
+
+class RawData(_message.Message):
+    __slots__ = ["packet"]
+    PACKET_FIELD_NUMBER: _ClassVar[int]
+    packet: bytes
+    def __init__(self, packet: _Optional[bytes] = ...) -> None: ...

bumble/transport/emulated_bluetooth_pb2_grpc.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -39,20 +39,20 @@ class EmulatedBluetoothServiceStub(object):
             channel: A grpc.Channel.
         """
         self.registerClassicPhy = channel.stream_stream(
-                '/android.emulation.bluetooth.EmulatedBluetoothService/registerClassicPhy',
-                request_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
-                response_deserializer=emulated__bluetooth__pb2.RawData.FromString,
-                )
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerClassicPhy',
+            request_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
+            response_deserializer=emulated__bluetooth__pb2.RawData.FromString,
+        )
         self.registerBlePhy = channel.stream_stream(
-                '/android.emulation.bluetooth.EmulatedBluetoothService/registerBlePhy',
-                request_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
-                response_deserializer=emulated__bluetooth__pb2.RawData.FromString,
-                )
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerBlePhy',
+            request_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
+            response_deserializer=emulated__bluetooth__pb2.RawData.FromString,
+        )
         self.registerHCIDevice = channel.stream_stream(
-                '/android.emulation.bluetooth.EmulatedBluetoothService/registerHCIDevice',
-                request_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
-                response_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-                )
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerHCIDevice',
+            request_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
+            response_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
+        )
 
 
 class EmulatedBluetoothServiceServicer(object):
@@ -121,28 +121,29 @@ class EmulatedBluetoothServiceServicer(object):
 
 def add_EmulatedBluetoothServiceServicer_to_server(servicer, server):
     rpc_method_handlers = {
-            'registerClassicPhy': grpc.stream_stream_rpc_method_handler(
-                    servicer.registerClassicPhy,
-                    request_deserializer=emulated__bluetooth__pb2.RawData.FromString,
-                    response_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
-            ),
-            'registerBlePhy': grpc.stream_stream_rpc_method_handler(
-                    servicer.registerBlePhy,
-                    request_deserializer=emulated__bluetooth__pb2.RawData.FromString,
-                    response_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
-            ),
-            'registerHCIDevice': grpc.stream_stream_rpc_method_handler(
-                    servicer.registerHCIDevice,
-                    request_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-                    response_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
-            ),
+        'registerClassicPhy': grpc.stream_stream_rpc_method_handler(
+            servicer.registerClassicPhy,
+            request_deserializer=emulated__bluetooth__pb2.RawData.FromString,
+            response_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
+        ),
+        'registerBlePhy': grpc.stream_stream_rpc_method_handler(
+            servicer.registerBlePhy,
+            request_deserializer=emulated__bluetooth__pb2.RawData.FromString,
+            response_serializer=emulated__bluetooth__pb2.RawData.SerializeToString,
+        ),
+        'registerHCIDevice': grpc.stream_stream_rpc_method_handler(
+            servicer.registerHCIDevice,
+            request_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
+            response_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
+        ),
     }
     generic_handler = grpc.method_handlers_generic_handler(
-            'android.emulation.bluetooth.EmulatedBluetoothService', rpc_method_handlers)
+        'android.emulation.bluetooth.EmulatedBluetoothService', rpc_method_handlers
+    )
     server.add_generic_rpc_handlers((generic_handler,))
 
 
- # This class is part of an EXPERIMENTAL API.
+# This class is part of an EXPERIMENTAL API.
 class EmulatedBluetoothService(object):
     """An Emulated Bluetooth Service exposes the emulated bluetooth chip from the
     android emulator. It allows you to register emulated bluetooth devices and
@@ -156,52 +157,88 @@ class EmulatedBluetoothService(object):
     """
 
     @staticmethod
-    def registerClassicPhy(request_iterator,
+    def registerClassicPhy(
+        request_iterator,
+        target,
+        options=(),
+        channel_credentials=None,
+        call_credentials=None,
+        insecure=False,
+        compression=None,
+        wait_for_ready=None,
+        timeout=None,
+        metadata=None,
+    ):
+        return grpc.experimental.stream_stream(
+            request_iterator,
             target,
-            options=(),
-            channel_credentials=None,
-            call_credentials=None,
-            insecure=False,
-            compression=None,
-            wait_for_ready=None,
-            timeout=None,
-            metadata=None):
-        return grpc.experimental.stream_stream(request_iterator, target, '/android.emulation.bluetooth.EmulatedBluetoothService/registerClassicPhy',
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerClassicPhy',
             emulated__bluetooth__pb2.RawData.SerializeToString,
             emulated__bluetooth__pb2.RawData.FromString,
-            options, channel_credentials,
-            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )
 
     @staticmethod
-    def registerBlePhy(request_iterator,
+    def registerBlePhy(
+        request_iterator,
+        target,
+        options=(),
+        channel_credentials=None,
+        call_credentials=None,
+        insecure=False,
+        compression=None,
+        wait_for_ready=None,
+        timeout=None,
+        metadata=None,
+    ):
+        return grpc.experimental.stream_stream(
+            request_iterator,
             target,
-            options=(),
-            channel_credentials=None,
-            call_credentials=None,
-            insecure=False,
-            compression=None,
-            wait_for_ready=None,
-            timeout=None,
-            metadata=None):
-        return grpc.experimental.stream_stream(request_iterator, target, '/android.emulation.bluetooth.EmulatedBluetoothService/registerBlePhy',
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerBlePhy',
             emulated__bluetooth__pb2.RawData.SerializeToString,
             emulated__bluetooth__pb2.RawData.FromString,
-            options, channel_credentials,
-            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )
 
     @staticmethod
-    def registerHCIDevice(request_iterator,
+    def registerHCIDevice(
+        request_iterator,
+        target,
+        options=(),
+        channel_credentials=None,
+        call_credentials=None,
+        insecure=False,
+        compression=None,
+        wait_for_ready=None,
+        timeout=None,
+        metadata=None,
+    ):
+        return grpc.experimental.stream_stream(
+            request_iterator,
             target,
-            options=(),
-            channel_credentials=None,
-            call_credentials=None,
-            insecure=False,
-            compression=None,
-            wait_for_ready=None,
-            timeout=None,
-            metadata=None):
-        return grpc.experimental.stream_stream(request_iterator, target, '/android.emulation.bluetooth.EmulatedBluetoothService/registerHCIDevice',
+            '/android.emulation.bluetooth.EmulatedBluetoothService/registerHCIDevice',
             emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
             emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-            options, channel_credentials,
-            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )

bumble/transport/emulated_bluetooth_vhci_pb2.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,28 +16,31 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # source: emulated_bluetooth_vhci.proto
 """Generated protocol buffer code."""
+from google.protobuf.internal import builder as _builder
 from google.protobuf import descriptor as _descriptor
 from google.protobuf import descriptor_pool as _descriptor_pool
-from google.protobuf import message as _message
-from google.protobuf import reflection as _reflection
 from google.protobuf import symbol_database as _symbol_database
+
 # @@protoc_insertion_point(imports)
 
 _sym_db = _symbol_database.Default()
 
 
-import emulated_bluetooth_packets_pb2 as emulated__bluetooth__packets__pb2
+from . import emulated_bluetooth_packets_pb2 as emulated__bluetooth__packets__pb2
 
 
-DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x1d\x65mulated_bluetooth_vhci.proto\x12\x1b\x61ndroid.emulation.bluetooth\x1a emulated_bluetooth_packets.proto2y\n\x15VhciForwardingService\x12`\n\nattachVhci\x12&.android.emulation.bluetooth.HCIPacket\x1a&.android.emulation.bluetooth.HCIPacket(\x01\x30\x01\x42J\n\x1f\x63om.android.emulation.bluetoothP\x01\xf8\x01\x01\xa2\x02\x03\x41\x45\x42\xaa\x02\x1b\x41ndroid.Emulation.Bluetoothb\x06proto3')
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(
+    b'\n\x1d\x65mulated_bluetooth_vhci.proto\x12\x1b\x61ndroid.emulation.bluetooth\x1a emulated_bluetooth_packets.proto2y\n\x15VhciForwardingService\x12`\n\nattachVhci\x12&.android.emulation.bluetooth.HCIPacket\x1a&.android.emulation.bluetooth.HCIPacket(\x01\x30\x01\x42J\n\x1f\x63om.android.emulation.bluetoothP\x01\xf8\x01\x01\xa2\x02\x03\x41\x45\x42\xaa\x02\x1b\x41ndroid.Emulation.Bluetoothb\x06proto3'
+)
 
-
-
-_VHCIFORWARDINGSERVICE = DESCRIPTOR.services_by_name['VhciForwardingService']
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
+_builder.BuildTopDescriptorsAndMessages(
+    DESCRIPTOR, 'emulated_bluetooth_vhci_pb2', globals()
+)
 if _descriptor._USE_C_DESCRIPTORS == False:
 
-  DESCRIPTOR._options = None
-  DESCRIPTOR._serialized_options = b'\n\037com.android.emulation.bluetoothP\001\370\001\001\242\002\003AEB\252\002\033Android.Emulation.Bluetooth'
-  _VHCIFORWARDINGSERVICE._serialized_start=96
-  _VHCIFORWARDINGSERVICE._serialized_end=217
+    DESCRIPTOR._options = None
+    DESCRIPTOR._serialized_options = b'\n\037com.android.emulation.bluetoothP\001\370\001\001\242\002\003AEB\252\002\033Android.Emulation.Bluetooth'
+    _VHCIFORWARDINGSERVICE._serialized_start = 96
+    _VHCIFORWARDINGSERVICE._serialized_end = 217
 # @@protoc_insertion_point(module_scope)

bumble/transport/emulated_bluetooth_vhci_pb2.pyi

@@ -0,0 +1,19 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import emulated_bluetooth_packets_pb2 as _emulated_bluetooth_packets_pb2
+from google.protobuf import descriptor as _descriptor
+from typing import ClassVar as _ClassVar
+
+DESCRIPTOR: _descriptor.FileDescriptor

bumble/transport/emulated_bluetooth_vhci_pb2_grpc.py

@@ -1,4 +1,4 @@
-# Copyright 2021-2022 Google LLC
+# Copyright 2021-2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -35,10 +35,10 @@ class VhciForwardingServiceStub(object):
             channel: A grpc.Channel.
         """
         self.attachVhci = channel.stream_stream(
-                '/android.emulation.bluetooth.VhciForwardingService/attachVhci',
-                request_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
-                response_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-                )
+            '/android.emulation.bluetooth.VhciForwardingService/attachVhci',
+            request_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
+            response_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
+        )
 
 
 class VhciForwardingServiceServicer(object):
@@ -75,18 +75,19 @@ class VhciForwardingServiceServicer(object):
 
 def add_VhciForwardingServiceServicer_to_server(servicer, server):
     rpc_method_handlers = {
-            'attachVhci': grpc.stream_stream_rpc_method_handler(
-                    servicer.attachVhci,
-                    request_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-                    response_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
-            ),
+        'attachVhci': grpc.stream_stream_rpc_method_handler(
+            servicer.attachVhci,
+            request_deserializer=emulated__bluetooth__packets__pb2.HCIPacket.FromString,
+            response_serializer=emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
+        ),
     }
     generic_handler = grpc.method_handlers_generic_handler(
-            'android.emulation.bluetooth.VhciForwardingService', rpc_method_handlers)
+        'android.emulation.bluetooth.VhciForwardingService', rpc_method_handlers
+    )
     server.add_generic_rpc_handlers((generic_handler,))
 
 
- # This class is part of an EXPERIMENTAL API.
+# This class is part of an EXPERIMENTAL API.
 class VhciForwardingService(object):
     """This is a service which allows you to directly intercept the VHCI packets
     that are coming and going to the device before they are delivered to
@@ -97,18 +98,30 @@ class VhciForwardingService(object):
     """
 
     @staticmethod
-    def attachVhci(request_iterator,
+    def attachVhci(
+        request_iterator,
+        target,
+        options=(),
+        channel_credentials=None,
+        call_credentials=None,
+        insecure=False,
+        compression=None,
+        wait_for_ready=None,
+        timeout=None,
+        metadata=None,
+    ):
+        return grpc.experimental.stream_stream(
+            request_iterator,
             target,
-            options=(),
-            channel_credentials=None,
-            call_credentials=None,
-            insecure=False,
-            compression=None,
-            wait_for_ready=None,
-            timeout=None,
-            metadata=None):
-        return grpc.experimental.stream_stream(request_iterator, target, '/android.emulation.bluetooth.VhciForwardingService/attachVhci',
+            '/android.emulation.bluetooth.VhciForwardingService/attachVhci',
             emulated__bluetooth__packets__pb2.HCIPacket.SerializeToString,
             emulated__bluetooth__packets__pb2.HCIPacket.FromString,
-            options, channel_credentials,
-            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)
+            options,
+            channel_credentials,
+            insecure,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )

bumble/transport/file.py

@@ -30,8 +30,9 @@ logger = logging.getLogger(__name__)
 # -----------------------------------------------------------------------------
 async def open_file_transport(spec):
     '''
-    Open a File transport (typically not for a real file, but for a PTY or other unix virtual files).
-    The parameter string is the path of the file to open
+    Open a File transport (typically not for a real file, but for a PTY or other unix
+    virtual files).
+    The parameter string is the path of the file to open.
     '''
 
     # Open the file
@@ -39,14 +40,12 @@ async def open_file_transport(spec):
 
     # Setup reading
     read_transport, packet_source = await asyncio.get_running_loop().connect_read_pipe(
-        lambda: StreamPacketSource(),
-        file
+        StreamPacketSource, file
     )
 
     # Setup writing
     write_transport, _ = await asyncio.get_running_loop().connect_write_pipe(
-        lambda: asyncio.BaseProtocol(),
-        file
+        asyncio.BaseProtocol, file
     )
     packet_sink = StreamPacketSink(write_transport)
 
@@ -57,4 +56,3 @@ async def open_file_transport(spec):
             file.close()
 
     return FileTransport(packet_source, packet_sink)
-

bumble/transport/hci_socket.py

@@ -40,15 +40,21 @@ async def open_hci_socket_transport(spec):
     or a 0-based integer to indicate the adapter number.
     '''
 
-    HCI_CHANNEL_USER = 1
+    HCI_CHANNEL_USER = 1  # pylint: disable=invalid-name
 
     # Create a raw HCI socket
     try:
-        hci_socket = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_RAW | socket.SOCK_NONBLOCK, socket.BTPROTO_HCI)
-    except AttributeError:
+        hci_socket = socket.socket(
+            socket.AF_BLUETOOTH,
+            socket.SOCK_RAW | socket.SOCK_NONBLOCK,
+            socket.BTPROTO_HCI,
+        )
+    except AttributeError as error:
         # Not supported on this platform
         logger.info("HCI sockets not supported on this platform")
-        raise Exception('Bluetooth HCI sockets not supported on this platform')
+        raise Exception(
+            'Bluetooth HCI sockets not supported on this platform'
+        ) from error
 
     # Compute the adapter index
     if spec is None:
@@ -62,20 +68,37 @@ async def open_hci_socket_transport(spec):
     try:
         ctypes.cdll.LoadLibrary('libc.so.6')
         libc = ctypes.CDLL('libc.so.6', use_errno=True)
-    except OSError:
+    except OSError as error:
         logger.info("HCI sockets not supported on this platform")
-        raise Exception('Bluetooth HCI sockets not supported on this platform')
+        raise Exception(
+            'Bluetooth HCI sockets not supported on this platform'
+        ) from error
     libc.bind.argtypes = (ctypes.c_int, ctypes.POINTER(ctypes.c_char), ctypes.c_int)
     libc.bind.restype = ctypes.c_int
-    bind_address = struct.pack('<HHH', socket.AF_BLUETOOTH, adapter_index, HCI_CHANNEL_USER)
-    if libc.bind(hci_socket.fileno(), ctypes.create_string_buffer(bind_address), len(bind_address)) != 0:
+    bind_address = struct.pack(
+        # pylint: disable=no-member
+        '<HHH',
+        socket.AF_BLUETOOTH,
+        adapter_index,
+        HCI_CHANNEL_USER,
+    )
+    if (
+        libc.bind(
+            hci_socket.fileno(),
+            ctypes.create_string_buffer(bind_address),
+            len(bind_address),
+        )
+        != 0
+    ):
         raise IOError(ctypes.get_errno(), os.strerror(ctypes.get_errno()))
 
     class HciSocketSource(ParserSource):
-        def __init__(self, socket):
+        def __init__(self, hci_socket):
             super().__init__()
-            self.socket  = socket
-            asyncio.get_running_loop().add_reader(socket.fileno(), self.recv_until_would_block)
+            self.socket = hci_socket
+            asyncio.get_running_loop().add_reader(
+                self.socket.fileno(), self.recv_until_would_block
+            )
 
         def recv_until_would_block(self):
             logger.debug('recv until would block +++')
@@ -92,9 +115,9 @@ async def open_hci_socket_transport(spec):
             asyncio.get_running_loop().remove_reader(self.socket.fileno())
 
     class HciSocketSink:
-        def __init__(self, socket):
-            self.socket       = socket
-            self.packets      = collections.deque()
+        def __init__(self, hci_socket):
+            self.socket = hci_socket
+            self.packets = collections.deque()
             self.writer_added = False
 
         def send_until_would_block(self):
@@ -112,9 +135,14 @@ async def open_hci_socket_transport(spec):
                     break
 
             if self.packets:
-                # There's still something to send, ensure that we are monitoring the socket
+                # There's still something to send, ensure that we are monitoring the
+                # socket
                 if not self.writer_added:
-                    asyncio.get_running_loop().add_writer(socket.fileno(), self.send_until_would_block)
+                    asyncio.get_running_loop().add_writer(
+                        # pylint: disable=no-member
+                        self.socket.fileno(),
+                        self.send_until_would_block,
+                    )
                     self.writer_added = True
             else:
                 # Nothing left to send, stop monitoring the socket
@@ -131,9 +159,9 @@ async def open_hci_socket_transport(spec):
                 asyncio.get_running_loop().remove_writer(self.socket.fileno())
 
     class HciSocketTransport(Transport):
-        def __init__(self, socket, source, sink):
+        def __init__(self, hci_socket, source, sink):
             super().__init__(source, sink)
-            self.socket = socket
+            self.socket = hci_socket
 
         async def close(self):
             logger.debug('closing HCI socket transport')

bumble/transport/pty.py

@@ -47,13 +47,11 @@ async def open_pty_transport(spec):
     tty.setraw(replica)
 
     read_transport, packet_source = await asyncio.get_running_loop().connect_read_pipe(
-        lambda: StreamPacketSource(),
-        io.open(primary, 'rb', closefd=False)
+        StreamPacketSource, io.open(primary, 'rb', closefd=False)
     )
 
     write_transport, _ = await asyncio.get_running_loop().connect_write_pipe(
-        lambda: asyncio.BaseProtocol(),
-        io.open(primary, 'wb', closefd=False)
+        asyncio.BaseProtocol, io.open(primary, 'wb', closefd=False)
     )
     packet_sink = StreamPacketSink(write_transport)
 

bumble/transport/pyusb.py

@@ -17,14 +17,15 @@
 # -----------------------------------------------------------------------------
 import asyncio
 import logging
-import usb.core
-import usb.util
 import threading
 import time
-from colors import color
+
+import usb.core
+import usb.util
 
 from .common import Transport, ParserSource
 from .. import hci
+from ..colors import color
 
 
 # -----------------------------------------------------------------------------
@@ -48,25 +49,26 @@ async def open_pyusb_transport(spec):
     04b4:f901 --> the BT USB dongle with vendor=04b4 and product=f901
     '''
 
-    USB_RECIPIENT_DEVICE                             = 0x00
-    USB_REQUEST_TYPE_CLASS                           = 0x01 << 5
-    USB_ENDPOINT_EVENTS_IN                           = 0x81
-    USB_ENDPOINT_ACL_IN                              = 0x82
-    USB_ENDPOINT_SCO_IN                              = 0x83
-    USB_ENDPOINT_ACL_OUT                             = 0x02
+    # pylint: disable=invalid-name
+    USB_RECIPIENT_DEVICE = 0x00
+    USB_REQUEST_TYPE_CLASS = 0x01 << 5
+    USB_ENDPOINT_EVENTS_IN = 0x81
+    USB_ENDPOINT_ACL_IN = 0x82
+    USB_ENDPOINT_SCO_IN = 0x83
+    USB_ENDPOINT_ACL_OUT = 0x02
     #  USB_ENDPOINT_SCO_OUT                             = 0x03
-    USB_DEVICE_CLASS_WIRELESS_CONTROLLER             = 0xE0
-    USB_DEVICE_SUBCLASS_RF_CONTROLLER                = 0x01
+    USB_DEVICE_CLASS_WIRELESS_CONTROLLER = 0xE0
+    USB_DEVICE_SUBCLASS_RF_CONTROLLER = 0x01
     USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER = 0x01
 
-    READ_SIZE    = 1024
+    READ_SIZE = 1024
     READ_TIMEOUT = 1000
 
     class UsbPacketSink:
         def __init__(self, device):
-            self.device     = device
-            self.thread     = threading.Thread(target=self.run)
-            self.loop       = asyncio.get_running_loop()
+            self.device = device
+            self.thread = threading.Thread(target=self.run)
+            self.loop = asyncio.get_running_loop()
             self.stop_event = None
 
         def on_packet(self, packet):
@@ -80,9 +82,17 @@ async def open_pyusb_transport(spec):
                 if packet_type == hci.HCI_ACL_DATA_PACKET:
                     self.device.write(USB_ENDPOINT_ACL_OUT, packet[1:])
                 elif packet_type == hci.HCI_COMMAND_PACKET:
-                    self.device.ctrl_transfer(USB_RECIPIENT_DEVICE | USB_REQUEST_TYPE_CLASS, 0, 0, 0, packet[1:])
+                    self.device.ctrl_transfer(
+                        USB_RECIPIENT_DEVICE | USB_REQUEST_TYPE_CLASS,
+                        0,
+                        0,
+                        0,
+                        packet[1:],
+                    )
                 else:
-                    logger.warning(color(f'unsupported packet type {packet_type}', 'red'))
+                    logger.warning(
+                        color(f'unsupported packet type {packet_type}', 'red')
+                    )
             except usb.core.USBTimeoutError:
                 logger.warning('USB Write Timeout')
             except usb.core.USBError as error:
@@ -100,22 +110,21 @@ async def open_pyusb_transport(spec):
         def run(self):
             while self.stop_event is None:
                 time.sleep(1)
-            self.loop.call_soon_threadsafe(lambda: self.stop_event.set())
+            self.loop.call_soon_threadsafe(self.stop_event.set)
 
     class UsbPacketSource(asyncio.Protocol, ParserSource):
         def __init__(self, device, sco_enabled):
             super().__init__()
-            self.device       = device
-            self.loop         = asyncio.get_running_loop()
-            self.queue        = asyncio.Queue()
+            self.device = device
+            self.loop = asyncio.get_running_loop()
+            self.queue = asyncio.Queue()
+            self.dequeue_task = None
             self.event_thread = threading.Thread(
-                target=self.run,
-                args=(USB_ENDPOINT_EVENTS_IN, hci.HCI_EVENT_PACKET)
+                target=self.run, args=(USB_ENDPOINT_EVENTS_IN, hci.HCI_EVENT_PACKET)
             )
             self.event_thread.stop_event = None
             self.acl_thread = threading.Thread(
-                target=self.run,
-                args=(USB_ENDPOINT_ACL_IN, hci.HCI_ACL_DATA_PACKET)
+                target=self.run, args=(USB_ENDPOINT_ACL_IN, hci.HCI_ACL_DATA_PACKET)
             )
             self.acl_thread.stop_event = None
 
@@ -124,12 +133,12 @@ async def open_pyusb_transport(spec):
             if sco_enabled:
                 self.sco_thread = threading.Thread(
                     target=self.run,
-                    args=(USB_ENDPOINT_SCO_IN, hci.HCI_SYNCHRONOUS_DATA_PACKET)
+                    args=(USB_ENDPOINT_SCO_IN, hci.HCI_SYNCHRONOUS_DATA_PACKET),
                 )
                 self.sco_thread.stop_event = None
 
-        def data_received(self, packet):
-            self.parser.feed_data(packet)
+        def data_received(self, data):
+            self.parser.feed_data(data)
 
         def enqueue(self, packet):
             self.queue.put_nowait(packet)
@@ -155,7 +164,7 @@ async def open_pyusb_transport(spec):
 
             # Create stop events and wait for them to be signaled
             self.event_thread.stop_event = asyncio.Event()
-            self.acl_thread.stop_event   = asyncio.Event()
+            self.acl_thread.stop_event = asyncio.Event()
             await self.event_thread.stop_event.wait()
             await self.acl_thread.stop_event.wait()
             if self.sco_enabled:
@@ -173,16 +182,17 @@ async def open_pyusb_transport(spec):
                 except usb.core.USBTimeoutError:
                     continue
                 except usb.core.USBError:
-                    # Don't log this: because pyusb doesn't really support multiple threads
-                    # reading at the same time, we can get occasional USBError(errno=5)
-                    # Input/Output errors reported, but they seem to be harmless.
+                    # Don't log this: because pyusb doesn't really support multiple
+                    # threads reading at the same time, we can get occasional
+                    # USBError(errno=5) Input/Output errors reported, but they seem to
+                    # be harmless.
                     # Until support for async or multi-thread support is added to pyusb,
                     # we'll just live with this as is...
                     # logger.warning(f'USB read error: {error}')
                     time.sleep(1)  # Sleep one second to avoid busy looping
 
             stop_event = current_thread.stop_event
-            self.loop.call_soon_threadsafe(lambda: stop_event.set())
+            self.loop.call_soon_threadsafe(stop_event.set)
 
     class UsbTransport(Transport):
         def __init__(self, device, source, sink):
@@ -194,18 +204,28 @@ async def open_pyusb_transport(spec):
             await self.sink.stop()
             usb.util.release_interface(self.device, 0)
 
+    usb_find = usb.core.find
+    try:
+        import libusb_package
+    except ImportError:
+        logger.debug('libusb_package is not available')
+    else:
+        usb_find = libusb_package.find
+
     # Find the device according to the spec moniker
     if ':' in spec:
         vendor_id, product_id = spec.split(':')
-        device = usb.core.find(idVendor=int(vendor_id, 16), idProduct=int(product_id, 16))
+        device = usb_find(idVendor=int(vendor_id, 16), idProduct=int(product_id, 16))
     else:
         device_index = int(spec)
-        devices = list(usb.core.find(
-            find_all        = 1,
-            bDeviceClass    = USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
-            bDeviceSubClass = USB_DEVICE_SUBCLASS_RF_CONTROLLER,
-            bDeviceProtocol = USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
-        ))
+        devices = list(
+            usb_find(
+                find_all=1,
+                bDeviceClass=USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
+                bDeviceSubClass=USB_DEVICE_SUBCLASS_RF_CONTROLLER,
+                bDeviceProtocol=USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER,
+            )
+        )
         if len(devices) > device_index:
             device = devices[device_index]
         else:
@@ -232,6 +252,7 @@ async def open_pyusb_transport(spec):
 
     # Select an alternate setting for SCO, if available
     sco_enabled = False
+    # pylint: disable=line-too-long
     # NOTE: this is disabled for now, because SCO with alternate settings is broken,
     # see: https://github.com/libusb/libusb/issues/36
     #
@@ -273,4 +294,4 @@ async def open_pyusb_transport(spec):
     packet_source.start()
     packet_sink.start()
 
-    return UsbTransport(device, packet_source, packet_sink)
+    return UsbTransport(device, packet_source, packet_sink)

bumble/transport/serial.py

@@ -60,13 +60,12 @@ async def open_serial_transport(spec):
         device = spec
     serial_transport, packet_source = await serial_asyncio.create_serial_connection(
         asyncio.get_running_loop(),
-        lambda: StreamPacketSource(),
+        StreamPacketSource,
         device,
         baudrate=speed,
         rtscts=rtscts,
-        dsrdtr=dsrdtr
+        dsrdtr=dsrdtr,
     )
     packet_sink = StreamPacketSink(serial_transport)
 
     return Transport(packet_source, packet_sink)
-

bumble/transport/tcp_client.py

@@ -37,13 +37,13 @@ async def open_tcp_client_transport(spec):
     '''
 
     class TcpPacketSource(StreamPacketSource):
-        def connection_lost(self, error):
-            logger.debug(f'connection lost: {error}')
-            self.terminated.set_result(error)
+        def connection_lost(self, exc):
+            logger.debug(f'connection lost: {exc}')
+            self.terminated.set_result(exc)
 
     remote_host, remote_port = spec.split(':')
     tcp_transport, packet_source = await asyncio.get_running_loop().create_connection(
-        lambda: TcpPacketSource(),
+        TcpPacketSource,
         host=remote_host,
         port=int(remote_port),
     )

bumble/transport/tcp_server.py

@@ -45,12 +45,12 @@ async def open_tcp_server_transport(spec):
     class TcpServerProtocol:
         def __init__(self, packet_source, packet_sink):
             self.packet_source = packet_source
-            self.packet_sink   = packet_sink
+            self.packet_sink = packet_sink
 
         # Called when a new connection is established
         def connection_made(self, transport):
-            peername = transport.get_extra_info('peername')
-            logger.debug('connection from {}'.format(peername))
+            peer_name = transport.get_extra_info('peer_name')
+            logger.debug(f'connection from {peer_name}')
             self.packet_sink.transport = transport
 
         # Called when the client is disconnected
@@ -78,7 +78,7 @@ async def open_tcp_server_transport(spec):
 
     local_host, local_port = spec.split(':')
     packet_source = StreamPacketSource()
-    packet_sink   = TcpServerPacketSink()
+    packet_sink = TcpServerPacketSink()
     await asyncio.get_running_loop().create_server(
         lambda: TcpServerProtocol(packet_source, packet_sink),
         host=local_host if local_host != '_' else None,

bumble/transport/udp.py

@@ -53,10 +53,13 @@ async def open_udp_transport(spec):
     local, remote = spec.split(',')
     local_host, local_port = local.split(':')
     remote_host, remote_port = remote.split(':')
-    udp_transport, packet_source = await asyncio.get_running_loop().create_datagram_endpoint(
-        lambda: UdpPacketSource(),
+    (
+        udp_transport,
+        packet_source,
+    ) = await asyncio.get_running_loop().create_datagram_endpoint(
+        UdpPacketSource,
         local_addr=(local_host, int(local_port)),
-        remote_addr=(remote_host, int(remote_port))
+        remote_addr=(remote_host, int(remote_port)),
     )
     packet_sink = UdpPacketSink(udp_transport)
 

bumble/transport/usb.py

@@ -17,13 +17,16 @@
 # -----------------------------------------------------------------------------
 import asyncio
 import logging
-import usb1
 import threading
 import collections
-from colors import color
+import ctypes
+import platform
+
+import usb1
 
 from .common import Transport, ParserSource
 from .. import hci
+from ..colors import color
 
 
 # -----------------------------------------------------------------------------
@@ -33,42 +36,88 @@ logger = logging.getLogger(__name__)
 
 
 # -----------------------------------------------------------------------------
+def load_libusb():
+    '''
+    Attempt to load the libusb-1.0 C library from libusb_package in site-packages.
+    If the library exists, we create a DLL object and initialize the usb1 backend.
+    This only needs to be done once, but before a usb1.USBContext is created.
+    If the library does not exists, do nothing and usb1 will search default system paths
+    when usb1.USBContext is created.
+    '''
+    try:
+        import libusb_package
+    except ImportError:
+        logger.debug('libusb_package is not available')
+    else:
+        if libusb_path := libusb_package.get_library_path():
+            logger.debug(f'loading libusb library at {libusb_path}')
+            dll_loader = (
+                ctypes.WinDLL if platform.system() == 'Windows' else ctypes.CDLL
+            )
+            libusb_dll = dll_loader(
+                str(libusb_path), use_errno=True, use_last_error=True
+            )
+            usb1.loadLibrary(libusb_dll)
+
+
 async def open_usb_transport(spec):
     '''
     Open a USB transport.
-    The parameter string has this syntax:
-    either <index> or <vendor>:<product>[/<serial-number>]
+    The moniker string has this syntax:
+    either <index> or
+    <vendor>:<product> or
+    <vendor>:<product>/<serial-number>] or
+    <vendor>:<product>#<index>
     With <index> as the 0-based index to select amongst all the devices that appear
     to be supporting Bluetooth HCI (0 being the first one), or
     Where <vendor> and <product> are the vendor ID and product ID in hexadecimal. The
-    /<serial-number> suffix max be specified when more than one device with the same
-    vendor and product identifiers are present.
+    /<serial-number> suffix or #<index> suffix max be specified when more than one
+    device with the same vendor and product identifiers are present.
+
+    In addition, if the moniker ends with the symbol "!", the device will be used in
+    "forced" mode:
+    the first USB interface of the device will be used, regardless of the interface
+    class/subclass.
+    This may be useful for some devices that use a custom class/subclass but may
+    nonetheless work as-is.
 
     Examples:
     0 --> the first BT USB dongle
     04b4:f901 --> the BT USB dongle with vendor=04b4 and product=f901
-    04b4:f901/00E04C239987 --> the BT USB dongle with vendor=04b4 and product=f901 and serial number 00E04C239987
+    04b4:f901#2 --> the third USB device with vendor=04b4 and product=f901
+    04b4:f901/00E04C239987 --> the BT USB dongle with vendor=04b4 and product=f901 and
+    serial number 00E04C239987
+    usb:0B05:17CB! --> the BT USB dongle vendor=0B05 and product=17CB, in "forced" mode.
     '''
 
-    USB_RECIPIENT_DEVICE                             = 0x00
-    USB_REQUEST_TYPE_CLASS                           = 0x01 << 5
-    USB_ENDPOINT_EVENTS_IN                           = 0x81
-    USB_ENDPOINT_ACL_IN                              = 0x82
-    USB_ENDPOINT_ACL_OUT                             = 0x02
-    USB_DEVICE_CLASS_WIRELESS_CONTROLLER             = 0xE0
-    USB_DEVICE_SUBCLASS_RF_CONTROLLER                = 0x01
+    # pylint: disable=invalid-name
+    USB_RECIPIENT_DEVICE = 0x00
+    USB_REQUEST_TYPE_CLASS = 0x01 << 5
+    USB_DEVICE_CLASS_DEVICE = 0x00
+    USB_DEVICE_CLASS_WIRELESS_CONTROLLER = 0xE0
+    USB_DEVICE_SUBCLASS_RF_CONTROLLER = 0x01
     USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER = 0x01
+    USB_ENDPOINT_TRANSFER_TYPE_BULK = 0x02
+    USB_ENDPOINT_TRANSFER_TYPE_INTERRUPT = 0x03
+    USB_ENDPOINT_IN = 0x80
+
+    USB_BT_HCI_CLASS_TUPLE = (
+        USB_DEVICE_CLASS_WIRELESS_CONTROLLER,
+        USB_DEVICE_SUBCLASS_RF_CONTROLLER,
+        USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER,
+    )
 
     READ_SIZE = 1024
 
     class UsbPacketSink:
-        def __init__(self, device):
-            self.device      = device
-            self.transfer    = device.getTransfer()
-            self.packets     = collections.deque()  # Queue of packets waiting to be sent
-            self.loop        = asyncio.get_running_loop()
+        def __init__(self, device, acl_out):
+            self.device = device
+            self.acl_out = acl_out
+            self.transfer = device.getTransfer()
+            self.packets = collections.deque()  # Queue of packets waiting to be sent
+            self.loop = asyncio.get_running_loop()
             self.cancel_done = self.loop.create_future()
-            self.closed      = False
+            self.closed = False
 
         def start(self):
             pass
@@ -92,12 +141,15 @@ async def open_usb_transport(spec):
             status = transfer.getStatus()
             # logger.debug(f'<<< USB out transfer callback: status={status}')
 
+            # pylint: disable=no-member
             if status == usb1.TRANSFER_COMPLETED:
                 self.loop.call_soon_threadsafe(self.on_packet_sent_)
             elif status == usb1.TRANSFER_CANCELLED:
                 self.loop.call_soon_threadsafe(self.cancel_done.set_result, None)
             else:
-                logger.warning(color(f'!!! out transfer not completed: status={status}', 'red'))
+                logger.warning(
+                    color(f'!!! out transfer not completed: status={status}', 'red')
+                )
 
         def on_packet_sent_(self):
             if self.packets:
@@ -112,32 +164,38 @@ async def open_usb_transport(spec):
             packet_type = packet[0]
             if packet_type == hci.HCI_ACL_DATA_PACKET:
                 self.transfer.setBulk(
-                    USB_ENDPOINT_ACL_OUT,
-                    packet[1:],
-                    callback=self.on_packet_sent
+                    self.acl_out, packet[1:], callback=self.on_packet_sent
                 )
                 logger.debug('submit ACL')
                 self.transfer.submit()
             elif packet_type == hci.HCI_COMMAND_PACKET:
                 self.transfer.setControl(
-                    USB_RECIPIENT_DEVICE | USB_REQUEST_TYPE_CLASS, 0, 0, 0,
+                    USB_RECIPIENT_DEVICE | USB_REQUEST_TYPE_CLASS,
+                    0,
+                    0,
+                    0,
                     packet[1:],
-                    callback=self.on_packet_sent
+                    callback=self.on_packet_sent,
                 )
                 logger.debug('submit COMMAND')
                 self.transfer.submit()
             else:
                 logger.warning(color(f'unsupported packet type {packet_type}', 'red'))
 
-        async def close(self):
+        def close(self):
             self.closed = True
 
+        async def terminate(self):
+            if not self.closed:
+                self.close()
+
             # Empty the packet queue so that we don't send any more data
             self.packets.clear()
 
             # If we have a transfer in flight, cancel it
             if self.transfer.isSubmitted():
-                # Try to cancel the transfer, but that may fail because it may have already completed
+                # Try to cancel the transfer, but that may fail because it may have
+                # already completed
                 try:
                     self.transfer.cancel()
 
@@ -148,18 +206,23 @@ async def open_usb_transport(spec):
                     logger.debug('OUT transfer likely already completed')
 
     class UsbPacketSource(asyncio.Protocol, ParserSource):
-        def __init__(self, context, device):
+        def __init__(self, context, device, acl_in, events_in):
             super().__init__()
-            self.context         = context
-            self.device          = device
-            self.loop            = asyncio.get_running_loop()
-            self.queue           = asyncio.Queue()
-            self.closed          = False
+            self.context = context
+            self.device = device
+            self.acl_in = acl_in
+            self.events_in = events_in
+            self.loop = asyncio.get_running_loop()
+            self.queue = asyncio.Queue()
+            self.dequeue_task = None
+            self.closed = False
             self.event_loop_done = self.loop.create_future()
             self.cancel_done = {
-                hci.HCI_EVENT_PACKET:    self.loop.create_future(),
-                hci.HCI_ACL_DATA_PACKET: self.loop.create_future()
+                hci.HCI_EVENT_PACKET: self.loop.create_future(),
+                hci.HCI_ACL_DATA_PACKET: self.loop.create_future(),
             }
+            self.events_in_transfer = None
+            self.acl_in_transfer = None
 
             # Create a thread to process events
             self.event_thread = threading.Thread(target=self.run)
@@ -168,19 +231,19 @@ async def open_usb_transport(spec):
             # Set up transfer objects for input
             self.events_in_transfer = device.getTransfer()
             self.events_in_transfer.setInterrupt(
-                USB_ENDPOINT_EVENTS_IN,
+                self.events_in,
                 READ_SIZE,
                 callback=self.on_packet_received,
-                user_data=hci.HCI_EVENT_PACKET
+                user_data=hci.HCI_EVENT_PACKET,
             )
             self.events_in_transfer.submit()
 
             self.acl_in_transfer = device.getTransfer()
             self.acl_in_transfer.setBulk(
-                USB_ENDPOINT_ACL_IN,
+                self.acl_in,
                 READ_SIZE,
                 callback=self.on_packet_received,
-                user_data=hci.HCI_ACL_DATA_PACKET
+                user_data=hci.HCI_ACL_DATA_PACKET,
             )
             self.acl_in_transfer.submit()
 
@@ -190,16 +253,28 @@ async def open_usb_transport(spec):
         def on_packet_received(self, transfer):
             packet_type = transfer.getUserData()
             status = transfer.getStatus()
-            # logger.debug(f'<<< USB IN transfer callback: status={status} packet_type={packet_type}')
+            # logger.debug(
+            #     f'<<< USB IN transfer callback: status={status} '
+            #     f'packet_type={packet_type} '
+            #     f'length={transfer.getActualLength()}'
+            # )
 
+            # pylint: disable=no-member
             if status == usb1.TRANSFER_COMPLETED:
-                packet = bytes([packet_type]) + transfer.getBuffer()[:transfer.getActualLength()]
+                packet = (
+                    bytes([packet_type])
+                    + transfer.getBuffer()[: transfer.getActualLength()]
+                )
                 self.loop.call_soon_threadsafe(self.queue.put_nowait, packet)
             elif status == usb1.TRANSFER_CANCELLED:
-                self.loop.call_soon_threadsafe(self.cancel_done[packet_type].set_result, None)
+                self.loop.call_soon_threadsafe(
+                    self.cancel_done[packet_type].set_result, None
+                )
                 return
             else:
-                logger.warning(color(f'!!! transfer not completed: status={status}', 'red'))
+                logger.warning(
+                    color(f'!!! transfer not completed: status={status}', 'red')
+                )
 
             # Re-submit the transfer so we can receive more data
             transfer.submit()
@@ -214,7 +289,11 @@ async def open_usb_transport(spec):
 
         def run(self):
             logger.debug('starting USB event loop')
-            while self.events_in_transfer.isSubmitted() or self.acl_in_transfer.isSubmitted():
+            while (
+                self.events_in_transfer.isSubmitted()
+                or self.acl_in_transfer.isSubmitted()
+            ):
+                # pylint: disable=no-member
                 try:
                     self.context.handleEvents()
                 except usb1.USBErrorInterrupted:
@@ -223,75 +302,130 @@ async def open_usb_transport(spec):
             logger.debug('USB event loop done')
             self.loop.call_soon_threadsafe(self.event_loop_done.set_result, None)
 
-        async def close(self):
+        def close(self):
             self.closed = True
+
+        async def terminate(self):
+            if not self.closed:
+                self.close()
+
             self.dequeue_task.cancel()
 
             # Cancel the transfers
             for transfer in (self.events_in_transfer, self.acl_in_transfer):
                 if transfer.isSubmitted():
-                    # Try to cancel the transfer, but that may fail because it may have already completed
+                    # Try to cancel the transfer, but that may fail because it may have
+                    # already completed
                     packet_type = transfer.getUserData()
                     try:
                         transfer.cancel()
-                        logger.debug(f'waiting for IN[{packet_type}] transfer cancellation to be done...')
+                        logger.debug(
+                            f'waiting for IN[{packet_type}] transfer cancellation '
+                            'to be done...'
+                        )
                         await self.cancel_done[packet_type]
                         logger.debug(f'IN[{packet_type}] transfer cancellation done')
                     except usb1.USBError:
-                        logger.debug(f'IN[{packet_type}] transfer likely already completed')
+                        logger.debug(
+                            f'IN[{packet_type}] transfer likely already completed'
+                        )
 
             # Wait for the thread to terminate
             await self.event_loop_done
 
     class UsbTransport(Transport):
-        def __init__(self, context, device, interface, source, sink):
+        def __init__(self, context, device, interface, setting, source, sink):
             super().__init__(source, sink)
-            self.context   = context
-            self.device    = device
+            self.context = context
+            self.device = device
             self.interface = interface
 
             # Get exclusive access
             device.claimInterface(interface)
 
+            # Set the alternate setting if not the default
+            if setting != 0:
+                device.setInterfaceAltSetting(interface, setting)
+
             # The source and sink can now start
             source.start()
             sink.start()
 
         async def close(self):
-            await self.source.close()
-            await self.sink.close()
+            self.source.close()
+            self.sink.close()
+            await self.source.terminate()
+            await self.sink.terminate()
             self.device.releaseInterface(self.interface)
             self.device.close()
             self.context.close()
 
     # Find the device according to the spec moniker
+    load_libusb()
     context = usb1.USBContext()
     context.open()
     try:
         found = None
+
+        if spec.endswith('!'):
+            spec = spec[:-1]
+            forced_mode = True
+        else:
+            forced_mode = False
+
         if ':' in spec:
             vendor_id, product_id = spec.split(':')
+            serial_number = None
+            device_index = 0
             if '/' in product_id:
                 product_id, serial_number = product_id.split('/')
-                for device in context.getDeviceIterator(skip_on_error=True):
-                    if (
-                        device.getVendorID() == int(vendor_id, 16) and
-                        device.getProductID() == int(product_id, 16) and
-                        device.getSerialNumber() == serial_number
-                    ):
+            elif '#' in product_id:
+                product_id, device_index_str = product_id.split('#')
+                device_index = int(device_index_str)
+
+            for device in context.getDeviceIterator(skip_on_error=True):
+                try:
+                    device_serial_number = device.getSerialNumber()
+                except usb1.USBError:
+                    device_serial_number = None
+                if (
+                    device.getVendorID() == int(vendor_id, 16)
+                    and device.getProductID() == int(product_id, 16)
+                    and (serial_number is None or serial_number == device_serial_number)
+                ):
+                    if device_index == 0:
                         found = device
                         break
-                    device.close()
-            else:
-                found = context.getByVendorIDAndProductID(int(vendor_id, 16), int(product_id, 16), skip_on_error=True)
+                    device_index -= 1
+                device.close()
         else:
+            # Look for a compatible device by index
+            def device_is_bluetooth_hci(device):
+                # Check if the device class indicates a match
+                if (
+                    device.getDeviceClass(),
+                    device.getDeviceSubClass(),
+                    device.getDeviceProtocol(),
+                ) == USB_BT_HCI_CLASS_TUPLE:
+                    return True
+
+                # If the device class is 'Device', look for a matching interface
+                if device.getDeviceClass() == USB_DEVICE_CLASS_DEVICE:
+                    for configuration in device:
+                        for interface in configuration:
+                            for setting in interface:
+                                if (
+                                    setting.getClass(),
+                                    setting.getSubClass(),
+                                    setting.getProtocol(),
+                                ) == USB_BT_HCI_CLASS_TUPLE:
+                                    return True
+
+                return False
+
             device_index = int(spec)
             for device in context.getDeviceIterator(skip_on_error=True):
-                if (
-                    device.getDeviceClass()    == USB_DEVICE_CLASS_WIRELESS_CONTROLLER and
-                    device.getDeviceSubClass() == USB_DEVICE_SUBCLASS_RF_CONTROLLER and
-                    device.getDeviceProtocol() == USB_DEVICE_PROTOCOL_BLUETOOTH_PRIMARY_CONTROLLER
-                ):
+                if device_is_bluetooth_hci(device):
                     if device_index == 0:
                         found = device
                         break
@@ -303,34 +437,107 @@ async def open_usb_transport(spec):
             raise ValueError('device not found')
 
         logger.debug(f'USB Device: {found}')
+
+        # Look for the first interface with the right class and endpoints
+        def find_endpoints(device):
+            # pylint: disable-next=too-many-nested-blocks
+            for (configuration_index, configuration) in enumerate(device):
+                interface = None
+                for interface in configuration:
+                    setting = None
+                    for setting in interface:
+                        if (
+                            not forced_mode
+                            and (
+                                setting.getClass(),
+                                setting.getSubClass(),
+                                setting.getProtocol(),
+                            )
+                            != USB_BT_HCI_CLASS_TUPLE
+                        ):
+                            continue
+
+                        events_in = None
+                        acl_in = None
+                        acl_out = None
+                        for endpoint in setting:
+                            attributes = endpoint.getAttributes()
+                            address = endpoint.getAddress()
+                            if attributes & 0x03 == USB_ENDPOINT_TRANSFER_TYPE_BULK:
+                                if address & USB_ENDPOINT_IN and acl_in is None:
+                                    acl_in = address
+                                elif acl_out is None:
+                                    acl_out = address
+                            elif (
+                                attributes & 0x03
+                                == USB_ENDPOINT_TRANSFER_TYPE_INTERRUPT
+                            ):
+                                if address & USB_ENDPOINT_IN and events_in is None:
+                                    events_in = address
+
+                        # Return if we found all 3 endpoints
+                        if (
+                            acl_in is not None
+                            and acl_out is not None
+                            and events_in is not None
+                        ):
+                            return (
+                                configuration_index + 1,
+                                setting.getNumber(),
+                                setting.getAlternateSetting(),
+                                acl_in,
+                                acl_out,
+                                events_in,
+                            )
+
+                        logger.debug(
+                            f'skipping configuration {configuration_index + 1} / '
+                            f'interface {setting.getNumber()}'
+                        )
+
+            return None
+
+        endpoints = find_endpoints(found)
+        if endpoints is None:
+            raise ValueError('no compatible interface found for device')
+        (configuration, interface, setting, acl_in, acl_out, events_in) = endpoints
+        logger.debug(
+            f'selected endpoints: configuration={configuration}, '
+            f'interface={interface}, '
+            f'setting={setting}, '
+            f'acl_in=0x{acl_in:02X}, '
+            f'acl_out=0x{acl_out:02X}, '
+            f'events_in=0x{events_in:02X}, '
+        )
+
         device = found.open()
 
+        # Auto-detach the kernel driver if supported
+        # pylint: disable=no-member
+        if usb1.hasCapability(usb1.CAP_SUPPORTS_DETACH_KERNEL_DRIVER):
+            try:
+                logger.debug('auto-detaching kernel driver')
+                device.setAutoDetachKernelDriver(True)
+            except usb1.USBError as error:
+                logger.warning(f'unable to auto-detach kernel driver: {error}')
+
         # Set the configuration if needed
         try:
-            configuration = device.getConfiguration()
-            logger.debug(f'current configuration = {configuration}')
+            current_configuration = device.getConfiguration()
+            logger.debug(f'current configuration = {current_configuration}')
         except usb1.USBError:
+            current_configuration = 0
+
+        if current_configuration != configuration:
             try:
-                logger.debug('setting configuration 1')
-                device.setConfiguration(1)
+                logger.debug(f'setting configuration {configuration}')
+                device.setConfiguration(configuration)
             except usb1.USBError:
-                logger.debug('failed to set configuration 1')
+                logger.warning('failed to set configuration')
 
-        # Use the first interface
-        interface = 0
-
-        # Detach the kernel driver if supported and needed
-        if usb1.hasCapability(usb1.CAP_SUPPORTS_DETACH_KERNEL_DRIVER):
-            try:
-                if device.kernelDriverActive(interface):
-                    logger.debug("detaching kernel driver")
-                    device.detachKernelDriver(interface)
-            except usb1.USBError:
-                pass
-
-        source = UsbPacketSource(context, device)
-        sink   = UsbPacketSink(device)
-        return UsbTransport(context, device, interface, source, sink)
+        source = UsbPacketSource(context, device, acl_in, events_in)
+        sink = UsbPacketSink(device, acl_out)
+        return UsbTransport(context, device, interface, setting, source, sink)
     except usb1.USBError as error:
         logger.warning(color(f'!!! failed to open USB device: {error}', 'red'))
         context.close()

bumble/transport/vhci.py

@@ -33,7 +33,7 @@ async def open_vhci_transport(spec):
     path at /dev/vhci), or the path of a VHCI device
     '''
 
-    HCI_VENDOR_PKT = 0xff
+    HCI_VENDOR_PKT = 0xFF
     HCI_BREDR = 0x00  # Controller type
 
     # Open the VHCI device
@@ -56,4 +56,3 @@ async def open_vhci_transport(spec):
     transport.sink.on_packet(bytes([HCI_VENDOR_PKT, HCI_BREDR]))
 
     return transport
-

bumble/transport/ws_client.py

@@ -43,7 +43,7 @@ async def open_ws_client_transport(spec):
     transport = PumpedTransport(
         PumpedPacketSource(websocket.recv),
         PumpedPacketSink(websocket.send),
-        websocket.close
+        websocket.close,
     )
     transport.start()
     return transport

bumble/transport/ws_server.py

@@ -41,30 +41,36 @@ async def open_ws_server_transport(spec):
 
     class WsServerTransport(Transport):
         def __init__(self):
-            source          = ParserSource()
-            sink            = PumpedPacketSink(self.send_packet)
+            source = ParserSource()
+            sink = PumpedPacketSink(self.send_packet)
             self.connection = asyncio.get_running_loop().create_future()
+            self.server = None
 
             super().__init__(source, sink)
 
         async def serve(self, local_host, local_port):
             self.sink.start()
+            # pylint: disable-next=no-member
             self.server = await websockets.serve(
-                ws_handler = self.on_connection,
-                host       = local_host if local_host != '_' else None,
-                port       = int(local_port)
+                ws_handler=self.on_connection,
+                host=local_host if local_host != '_' else None,
+                port=int(local_port),
             )
             logger.debug(f'websocket server ready on port {local_port}')
 
         async def on_connection(self, connection):
-            logger.debug(f'new connection on {connection.local_address} from {connection.remote_address}')
+            logger.debug(
+                f'new connection on {connection.local_address} '
+                f'from {connection.remote_address}'
+            )
             self.connection.set_result(connection)
+            # pylint: disable=no-member
             try:
                 async for packet in connection:
-                    if type(packet) is bytes:
+                    if isinstance(packet, bytes):
                         self.source.parser.feed_data(packet)
                     else:
-                        logger.warn('discarding packet: not a BINARY frame')
+                        logger.warning('discarding packet: not a BINARY frame')
             except websockets.WebSocketException as error:
                 logger.debug(f'exception while receiving packet: {error}')
 

bumble/utils.py

@@ -18,10 +18,13 @@
 import asyncio
 import logging
 import traceback
+import collections
+import sys
+from typing import Awaitable, Set, TypeVar
 from functools import wraps
-from colors import color
 from pyee import EventEmitter
 
+from .colors import color
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -33,6 +36,7 @@ logger = logging.getLogger(__name__)
 def setup_event_forwarding(emitter, forwarder, event_name):
     def emit(*args, **kwargs):
         forwarder.emit(event_name, *args, **kwargs)
+
     emitter.on(event_name, emit)
 
 
@@ -43,6 +47,8 @@ def composite_listener(cls):
     registers/deregisters all methods named `on_<event_name>` as a listener for
     the <event_name> event with an emitter.
     """
+    # pylint: disable=protected-access
+
     def register(self, emitter):
         for method_name in dir(cls):
             if method_name.startswith('on_'):
@@ -53,13 +59,47 @@ def composite_listener(cls):
             if method_name.startswith('on_'):
                 emitter.remove_listener(method_name[3:], getattr(self, method_name))
 
-    cls._bumble_register_composite   = register
+    cls._bumble_register_composite = register
     cls._bumble_deregister_composite = deregister
     return cls
 
 
 # -----------------------------------------------------------------------------
-class CompositeEventEmitter(EventEmitter):
+_T = TypeVar('_T')
+
+
+class AbortableEventEmitter(EventEmitter):
+    def abort_on(self, event: str, awaitable: Awaitable[_T]) -> Awaitable[_T]:
+        """
+        Set a coroutine or future to abort when an event occur.
+        """
+        future = asyncio.ensure_future(awaitable)
+        if future.done():
+            return future
+
+        def on_event(*_):
+            if future.done():
+                return
+            msg = f'abort: {event} event occurred.'
+            if isinstance(future, asyncio.Task):
+                # python < 3.9 does not support passing a message on `Task.cancel`
+                if sys.version_info < (3, 9, 0):
+                    future.cancel()
+                else:
+                    future.cancel(msg)
+            else:
+                future.set_exception(asyncio.CancelledError(msg))
+
+        def on_done(_):
+            self.remove_listener(event, on_event)
+
+        self.on(event, on_event)
+        future.add_done_callback(on_done)
+        return future
+
+
+# -----------------------------------------------------------------------------
+class CompositeEventEmitter(AbortableEventEmitter):
     def __init__(self):
         super().__init__()
         self._listener = None
@@ -70,6 +110,7 @@ class CompositeEventEmitter(EventEmitter):
 
     @listener.setter
     def listener(self, listener):
+        # pylint: disable=protected-access
         if self._listener:
             # Call the deregistration methods for each base class that has them
             for cls in self._listener.__class__.mro():
@@ -109,11 +150,16 @@ class AsyncRunner:
                 try:
                     await item
                 except Exception as error:
-                    logger.warning(f'{color("!!! Exception in work queue:", "red")} {error}')
+                    logger.warning(
+                        f'{color("!!! Exception in work queue:", "red")} {error}'
+                    )
 
     # Shared default queue
     default_queue = WorkQueue()
 
+    # Shared set of running tasks
+    running_tasks: Set[Awaitable] = set()
+
     @staticmethod
     def run_in_task(queue=None):
         """
@@ -130,7 +176,10 @@ class AsyncRunner:
                         try:
                             await coroutine
                         except Exception:
-                            logger.warning(f'{color("!!! Exception in wrapper:", "red")} {traceback.format_exc()}')
+                            logger.warning(
+                                f'{color("!!! Exception in wrapper:", "red")} '
+                                f'{traceback.format_exc()}'
+                            )
 
                     asyncio.create_task(run())
                 else:
@@ -140,3 +189,116 @@ class AsyncRunner:
             return wrapper
 
         return decorator
+
+    @staticmethod
+    def spawn(coroutine):
+        """
+        Spawn a task to run a coroutine in a "fire and forget" mode.
+
+        Using this method instead of just calling `asyncio.create_task(coroutine)`
+        is necessary when you don't keep a reference to the task, because `asyncio`
+        only keeps weak references to alive tasks.
+        """
+        task = asyncio.create_task(coroutine)
+        AsyncRunner.running_tasks.add(task)
+        task.add_done_callback(AsyncRunner.running_tasks.remove)
+
+
+# -----------------------------------------------------------------------------
+class FlowControlAsyncPipe:
+    """
+    Asyncio pipe with flow control. When writing to the pipe, the source is
+    paused (by calling a function passed in when the pipe is created) if the
+    amount of queued data exceeds a specified threshold.
+    """
+
+    def __init__(
+        self,
+        pause_source,
+        resume_source,
+        write_to_sink=None,
+        drain_sink=None,
+        threshold=0,
+    ):
+        self.pause_source = pause_source
+        self.resume_source = resume_source
+        self.write_to_sink = write_to_sink
+        self.drain_sink = drain_sink
+        self.threshold = threshold
+        self.queue = collections.deque()  # Queue of packets
+        self.queued_bytes = 0  # Number of bytes in the queue
+        self.ready_to_pump = asyncio.Event()
+        self.paused = False
+        self.source_paused = False
+        self.pump_task = None
+
+    def start(self):
+        if self.pump_task is None:
+            self.pump_task = asyncio.create_task(self.pump())
+
+        self.check_pump()
+
+    def stop(self):
+        if self.pump_task is not None:
+            self.pump_task.cancel()
+            self.pump_task = None
+
+    def write(self, packet):
+        self.queued_bytes += len(packet)
+        self.queue.append(packet)
+
+        # Pause the source if we're over the threshold
+        if self.queued_bytes > self.threshold and not self.source_paused:
+            logger.debug(f'pausing source (queued={self.queued_bytes})')
+            self.pause_source()
+            self.source_paused = True
+
+        self.check_pump()
+
+    def pause(self):
+        if not self.paused:
+            self.paused = True
+            if not self.source_paused:
+                self.pause_source()
+                self.source_paused = True
+            self.check_pump()
+
+    def resume(self):
+        if self.paused:
+            self.paused = False
+            if self.source_paused:
+                self.resume_source()
+                self.source_paused = False
+            self.check_pump()
+
+    def can_pump(self):
+        return self.queue and not self.paused and self.write_to_sink is not None
+
+    def check_pump(self):
+        if self.can_pump():
+            self.ready_to_pump.set()
+        else:
+            self.ready_to_pump.clear()
+
+    async def pump(self):
+        while True:
+            # Wait until we can try to pump packets
+            await self.ready_to_pump.wait()
+
+            # Try to pump a packet
+            if self.can_pump():
+                packet = self.queue.pop()
+                self.write_to_sink(packet)
+                self.queued_bytes -= len(packet)
+
+                # Drain the sink if we can
+                if self.drain_sink:
+                    await self.drain_sink()
+
+                # Check if we can accept more
+                if self.queued_bytes <= self.threshold and self.source_paused:
+                    logger.debug(f'resuming source (queued={self.queued_bytes})')
+                    self.source_paused = False
+                    self.resume_source()
+
+            self.check_pump()

docs/README.md

@@ -2,7 +2,7 @@ Bumble Documentation
 ====================
 
 The documentation consists of a collection of markdown text files, with the root of the file
-hierarchy at `docs/mkdocs/src`, starting with `docs/mkdocs/src/index.md`. 
+hierarchy at `docs/mkdocs/src`, starting with `docs/mkdocs/src/index.md`.
 You can read the documentation as text, with any text viewer or your favorite markdown viewer,
 or generate a static HTML "site" using `mkdocs`, which you can then open with any browser.
 
@@ -14,9 +14,9 @@ The `mkdocs` directory contains all the data (actual documentation) and metadata
 `mkdocs/mkdocs.yml` contains the site configuration.
 `mkdocs/src/` is the directory where the actual documentation text, in markdown format, is located.
 
-To build, from the project's root directory:  
+To build, from the project's root directory:
 ```
-$ mkdocs build -f docs/mkdocs/mkdocs.yml 
+$ mkdocs build -f docs/mkdocs/mkdocs.yml
 ```
 
 You can then open `docs/mkdocs/site/index.html` with any web browser.

docs/images/logo.vectornator/Document.json

@@ -1 +1 @@
-{"date":644900643.85054696,"appVersion":"4.1.5","drawing":{"modificationDate":644894800.328192,"activeArtboardIndex":0,"settings":{"outlineMode":false,"isolateActiveLayer":false,"snapToEdges":false,"snapToPoints":false,"guidesVisible":true,"snapToGrid":false,"units":"Pixels","dimensionsVisible":true,"dynamicGuides":false,"isCMYKColorPreviewEnabled":false,"undoHistoryDisabled":false,"snapToGuides":true,"drawOnlyUsingPencil":false,"whiteBackground":false,"rulersVisible":true,"isTimeLapseWatermarkDisabled":false},"artboardPaths":["Artboard0.json"],"documentVersion":"unknown"}}
+{"date":644900643.85054696,"appVersion":"4.1.5","drawing":{"modificationDate":644894800.328192,"activeArtboardIndex":0,"settings":{"outlineMode":false,"isolateActiveLayer":false,"snapToEdges":false,"snapToPoints":false,"guidesVisible":true,"snapToGrid":false,"units":"Pixels","dimensionsVisible":true,"dynamicGuides":false,"isCMYKColorPreviewEnabled":false,"undoHistoryDisabled":false,"snapToGuides":true,"drawOnlyUsingPencil":false,"whiteBackground":false,"rulersVisible":true,"isTimeLapseWatermarkDisabled":false},"artboardPaths":["Artboard0.json"],"documentVersion":"unknown"}}

docs/images/logo.vectornator/Manifest.json

@@ -1 +1 @@
-{"documentJSONFilename":"Document.json","undoHistoryJSONFilename":"UndoHistory.json","fileFormatVersion":0,"thumbnailImageFilename":"Thumbnail.png"}
+{"documentJSONFilename":"Document.json","undoHistoryJSONFilename":"UndoHistory.json","fileFormatVersion":0,"thumbnailImageFilename":"Thumbnail.png"}

docs/images/logo_framed.vectornator/Document.json

@@ -1 +1 @@
-{"date":644900741.09290397,"appVersion":"4.1.5","drawing":{"modificationDate":644894800.328192,"activeArtboardIndex":0,"settings":{"outlineMode":false,"isolateActiveLayer":false,"snapToEdges":false,"snapToPoints":false,"guidesVisible":true,"snapToGrid":false,"units":"Pixels","dimensionsVisible":true,"dynamicGuides":false,"isCMYKColorPreviewEnabled":false,"undoHistoryDisabled":false,"snapToGuides":true,"drawOnlyUsingPencil":false,"whiteBackground":false,"rulersVisible":true,"isTimeLapseWatermarkDisabled":false},"artboardPaths":["Artboard0.json"],"documentVersion":"unknown"}}
+{"date":644900741.09290397,"appVersion":"4.1.5","drawing":{"modificationDate":644894800.328192,"activeArtboardIndex":0,"settings":{"outlineMode":false,"isolateActiveLayer":false,"snapToEdges":false,"snapToPoints":false,"guidesVisible":true,"snapToGrid":false,"units":"Pixels","dimensionsVisible":true,"dynamicGuides":false,"isCMYKColorPreviewEnabled":false,"undoHistoryDisabled":false,"snapToGuides":true,"drawOnlyUsingPencil":false,"whiteBackground":false,"rulersVisible":true,"isTimeLapseWatermarkDisabled":false},"artboardPaths":["Artboard0.json"],"documentVersion":"unknown"}}

docs/images/logo_framed.vectornator/Manifest.json

@@ -1 +1 @@
-{"documentJSONFilename":"Document.json","undoHistoryJSONFilename":"UndoHistory.json","fileFormatVersion":0,"thumbnailImageFilename":"Thumbnail.png"}
+{"documentJSONFilename":"Document.json","undoHistoryJSONFilename":"UndoHistory.json","fileFormatVersion":0,"thumbnailImageFilename":"Thumbnail.png"}

docs/mkdocs/mkdocs.yml

@@ -7,6 +7,8 @@ nav:
   - Getting Started: getting_started.md
   - Development:
     - Python Environments: development/python_environments.md
+    - Contributing: development/contributing.md
+    - Code Style: development/code_style.md
   - Use Cases:
     - Overview: use_cases/index.md
     - Use Case 1: use_cases/use_case_1.md
@@ -41,10 +43,15 @@ nav:
   - Apps & Tools:
     - Overview: apps_and_tools/index.md
     - Console: apps_and_tools/console.md
-    - Link Relay: apps_and_tools/link_relay.md
+    - Bench: apps_and_tools/bench.md
     - HCI Bridge: apps_and_tools/hci_bridge.md
     - Golden Gate Bridge: apps_and_tools/gg_bridge.md
     - Show: apps_and_tools/show.md
+    - GATT Dump: apps_and_tools/gatt_dump.md
+    - Pair: apps_and_tools/pair.md
+    - Unbond: apps_and_tools/unbond.md
+    - USB Probe: apps_and_tools/usb_probe.md
+    - Link Relay: apps_and_tools/link_relay.md
   - Hardware:
     - Overview: hardware/index.md
   - Platforms:
@@ -56,7 +63,7 @@ nav:
   - Examples:
     - Overview: examples/index.md
 
-copyright: Copyright 2021-2022 Google LLC
+copyright: Copyright 2021-2023 Google LLC
 
 theme:
   name: 'material'

docs/mkdocs/requirements.txt

@@ -1,6 +1,6 @@
 # This requirements file is for python3
-mkdocs == 1.2.3
-mkdocs-material == 7.1.7
-mkdocs-material-extensions == 1.0.1
-pymdown-extensions == 8.2
-mkdocstrings == 0.15.1
+mkdocs == 1.4.0
+mkdocs-material == 8.5.6
+mkdocs-material-extensions == 1.0.3
+pymdown-extensions == 9.6
+mkdocstrings-python == 0.7.1

docs/mkdocs/src/api/examples.md

@@ -1,2 +1,2 @@
 API EXAMPLES
-============
+============

docs/mkdocs/src/api/guide.md

@@ -1,2 +1,2 @@
 API DEVELOPER GUIDE
-===================
+===================

docs/mkdocs/src/api/reference.md

@@ -16,4 +16,3 @@ Bumble Python API
 
 ### HCI_Disconnect_Command
 ::: bumble.hci.HCI_Disconnect_Command
-

docs/mkdocs/src/apps_and_tools/bench.md

@@ -0,0 +1,158 @@
+BENCH TOOL
+==========
+
+The "bench" tool implements a number of different ways of measuring the
+throughput and/or latency between two devices.
+
+# General Usage
+
+```
+Usage: bench.py [OPTIONS] COMMAND [ARGS]...
+
+Options:
+  --device-config FILENAME        Device configuration file
+  --role [sender|receiver|ping|pong]
+  --mode [gatt-client|gatt-server|l2cap-client|l2cap-server|rfcomm-client|rfcomm-server]
+  --att-mtu MTU                   GATT MTU (gatt-client mode)  [23<=x<=517]
+  -s, --packet-size SIZE          Packet size (server role)  [8<=x<=4096]
+  -c, --packet-count COUNT        Packet count (server role)
+  -sd, --start-delay SECONDS      Start delay (server role)
+  --help                          Show this message and exit.
+
+Commands:
+  central     Run as a central (initiates the connection)
+  peripheral  Run as a peripheral (waits for a connection)
+```
+
+## Options for the ``central`` Command
+```
+Usage: bumble-bench central [OPTIONS] TRANSPORT
+
+  Run as a central (initiates the connection)
+
+Options:
+  --peripheral ADDRESS_OR_NAME    Address or name to connect to
+  --connection-interval, --ci CONNECTION_INTERVAL
+                                  Connection interval (in ms)
+  --phy [1m|2m|coded]             PHY to use
+  --help                          Show this message and exit.
+```
+
+
+To test once device against another, one of the two devices must be running 
+the ``peripheral`` command and the other the ``central`` command. The device
+running the ``peripheral`` command will accept connections from the device
+running the ``central`` command.
+When using Bluetooth LE (all modes except for ``rfcomm-server`` and ``rfcomm-client``utils),
+the default addresses configured in the tool should be sufficient. But when using 
+Bluetooth Classic, the address of the Peripheral must be specified on the Central 
+using the ``--peripheral`` option. The address will be printed by the Peripheral when
+it starts.
+
+Independently of whether the device is the Central or Peripheral, each device selects a
+``mode`` and and ``role`` to run as. The ``mode`` and ``role`` of the Central and Peripheral
+must be compatible.
+
+Device 1 mode     | Device 2 mode
+------------------|------------------
+``gatt-client``   | ``gatt-server``
+``l2cap-client``  | ``l2cap-server``
+``rfcomm-client`` | ``rfcomm-server``
+
+Device 1 role | Device 2 role
+--------------|--------------
+``sender``    | ``receiver``
+``ping``      | ``pong``
+
+
+# Examples
+
+In the following examples, we have two USB Bluetooth controllers, one on `usb:0` and
+the other on `usb:1`, and two consoles/terminals. We will run a command in each.
+
+!!! example "GATT Throughput"
+    Using the default mode and role for the Central and Peripheral.
+
+    In the first console/terminal:
+    ```
+    $ bumble-bench peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench central usb:1
+    ```
+
+    In this default configuration, the Central runs a Sender, as a GATT client, 
+    connecting to the Peripheral running a Receiver, as a GATT server.
+
+!!! example "L2CAP Throughput"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-server peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-client central usb:1
+    ```
+
+!!! example "RFComm Throughput"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --mode rfcomm-server peripheral usb:0
+    ```
+
+    NOTE: the BT address of the Peripheral will be printed out, use it with the
+    ``--peripheral`` option for the Central.
+
+    In this example, we use a larger packet size and packet count than the default.
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --mode rfcomm-client --packet-size 2000 --packet-count 100 central --peripheral 00:16:A4:5A:40:F2 usb:1
+    ```
+
+!!! example "Ping/Pong Latency"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --role pong peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --role ping central usb:1
+    ```
+
+!!! example "Reversed modes with GATT and custom connection interval"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --mode gatt-client peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --mode gatt-server central --ci 10 usb:1
+    ```
+
+!!! example "Reversed modes with L2CAP and custom PHY"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-client peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-server central --phy 2m usb:1
+    ```
+
+!!! example "Reversed roles with L2CAP"
+    In the first console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-client --role sender peripheral usb:0
+    ```
+
+    In the second console/terminal:
+    ```
+    $ bumble-bench --mode l2cap-server --role receiver central usb:1
+    ```

docs/mkdocs/src/apps_and_tools/console.md

@@ -7,10 +7,12 @@ The Console app is an interactive text user interface that offers a number of fu
 
   * scanning
   * advertising
-  * connecting to devices
+  * connecting to and disconnecting from devices
   * changing connection parameters
+  * enabling encryption
   * discovering GATT services and characteristics
-  * read & write GATT characteristics
+  * reading and writing GATT characteristics
+  * subscribing to and unsubscribing from GATT characteristics
 
 The console user interface has 3 main panes:
 

docs/mkdocs/src/apps_and_tools/gg_bridge.md

@@ -1,2 +1,2 @@
 GOLDEN GATE BRIDGE
-==================
+==================

docs/mkdocs/src/apps_and_tools/hci_bridge.md

@@ -28,5 +28,3 @@ a host that send custom HCI commands that the controller may not understand.
     (through which the communication with other virtual controllers will be mediated).
 
     NOTE: this assumes you're running a Link Relay on port `10723`.
-
-

docs/mkdocs/src/apps_and_tools/index.md

@@ -5,10 +5,10 @@ Included in the project are a few apps and tools, built on top of the core libra
 These include:
 
   * [Console](console.md) - an interactive text-based console
+  * [Bench](bench.md) - Speed and Latency benchmarking between two devices (LE and Classic)
   * [Pair](pair.md) - Pair/bond two devices (LE and Classic)
   * [Unbond](unbond.md) - Remove a previously established bond
   * [HCI Bridge](hci_bridge.md) - a HCI transport bridge to connect two HCI transports and filter/snoop the HCI packets
   * [Golden Gate Bridge](gg_bridge.md) - a bridge between GATT and UDP to use with the Golden Gate "stack tool"
   * [Show](show.md) - Parse a file with HCI packets and print the details of each packet in a human readable form
   * [Link Relay](link_relay.md) - WebSocket relay for virtual RemoteLink instances to communicate with each other.
-