diff --git a/apps/rfcomm_bridge.py b/apps/rfcomm_bridge.py new file mode 100644 index 00000000..f7a08724 --- /dev/null +++ b/apps/rfcomm_bridge.py @@ -0,0 +1,475 @@ +# Copyright 2024 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 time +from typing import Optional + +import click + +from bumble.colors import color +from bumble.device import Device, Connection +from bumble import core +from bumble import hci +from bumble import rfcomm +from bumble import transport +from bumble import utils + + +# ----------------------------------------------------------------------------- +# Constants +# ----------------------------------------------------------------------------- +DEFAULT_RFCOMM_UUID = "E6D55659-C8B4-4B85-96BB-B1143AF6D3AE" +DEFAULT_MTU = 4096 +DEFAULT_TCP_PORT = 9544 + +TRACE_MAX_SIZE = 48 + + +# ----------------------------------------------------------------------------- +class Tracer: + """ + Trace data buffers transmitted from one endpoint to another, with stats. + """ + + def __init__(self, channel_name: str) -> None: + self.channel_name = channel_name + self.last_ts: float = 0.0 + + def trace_data(self, data: bytes) -> None: + now = time.time() + elapsed_s = now - self.last_ts if self.last_ts else 0 + elapsed_ms = int(elapsed_s * 1000) + instant_throughput_kbps = ((len(data) / elapsed_s) / 1000) if elapsed_s else 0.0 + + hex_str = data[:TRACE_MAX_SIZE].hex() + ( + "..." if len(data) > TRACE_MAX_SIZE else "" + ) + print( + f"[{self.channel_name}] {len(data):4} bytes " + f"(+{elapsed_ms:4}ms, {instant_throughput_kbps: 7.2f}kB/s) " + f" {hex_str}" + ) + + self.last_ts = now + + +# ----------------------------------------------------------------------------- +class ServerBridge: + """ + RFCOMM server bridge: waits for a peer to connect an RFCOMM channel. + The RFCOMM channel may be associated with a UUID published in an SDP service + description, or simply be on a system-assigned channel number. + 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 RFCOMM channel is closed, the bridge disconnects the TCP socket + and waits for a new channel to be connected. + """ + + READ_CHUNK_SIZE = 4096 + + def __init__( + self, channel: int, uuid: str, trace: bool, tcp_host: str, tcp_port: int + ) -> None: + self.device: Optional[Device] = None + self.channel = channel + self.uuid = uuid + self.tcp_host = tcp_host + self.tcp_port = tcp_port + self.rfcomm_channel: Optional[rfcomm.DLC] = None + self.tcp_tracer: Optional[Tracer] + self.rfcomm_tracer: Optional[Tracer] + + if trace: + self.tcp_tracer = Tracer(color("RFCOMM->TCP", "cyan")) + self.rfcomm_tracer = Tracer(color("TCP->RFCOMM", "magenta")) + else: + self.rfcomm_tracer = None + self.tcp_tracer = None + + async def start(self, device: Device) -> None: + self.device = device + + # Create and register a server + rfcomm_server = rfcomm.Server(self.device) + + # Listen for incoming DLC connections + self.channel = rfcomm_server.listen(self.on_rfcomm_channel, self.channel) + + # Setup the SDP to advertise this channel + service_record_handle = 0x00010001 + self.device.sdp_service_records = { + service_record_handle: rfcomm.make_service_sdp_records( + service_record_handle, self.channel, core.UUID(self.uuid) + ) + } + + # We're ready for a connection + self.device.on("connection", self.on_connection) + await self.set_available(True) + + print( + color( + ( + f"### Listening for RFCOMM connection on {device.public_address}, " + f"channel {self.channel}" + ), + "yellow", + ) + ) + + async def set_available(self, available: bool): + # Become discoverable and connectable + assert self.device + await self.device.set_connectable(available) + await self.device.set_discoverable(available) + + def on_connection(self, connection): + print(color(f"@@@ Bluetooth connection: {connection}", "blue")) + connection.on("disconnection", self.on_disconnection) + + # Don't accept new connections until we're disconnected + utils.AsyncRunner.spawn(self.set_available(False)) + + def on_disconnection(self, reason: int): + print( + color("@@@ Bluetooth disconnection:", "blue"), + hci.HCI_Constant.error_name(reason), + ) + + # We're ready for a new connection + utils.AsyncRunner.spawn(self.set_available(True)) + + # Called when an RFCOMM channel is established + @utils.AsyncRunner.run_in_task() + async def on_rfcomm_channel(self, rfcomm_channel): + print(color("*** RFCOMM channel:", "cyan"), rfcomm_channel) + + # Connect to the TCP server + print( + color( + f"### Connecting to TCP {self.tcp_host}:{self.tcp_port}", + "yellow", + ) + ) + try: + reader, writer = await asyncio.open_connection(self.tcp_host, self.tcp_port) + except OSError: + print(color("!!! Connection failed", "red")) + await rfcomm_channel.disconnect() + return + + # Pipe data from RFCOMM to TCP + def on_rfcomm_channel_closed(): + print(color("*** RFCOMM channel closed", "cyan")) + writer.close() + + def write_rfcomm_data(data): + if self.rfcomm_tracer: + self.rfcomm_tracer.trace_data(data) + + writer.write(data) + + rfcomm_channel.sink = write_rfcomm_data + rfcomm_channel.on("close", on_rfcomm_channel_closed) + + # Pipe data from TCP to RFCOMM + while True: + try: + data = await reader.read(self.READ_CHUNK_SIZE) + + if len(data) == 0: + print(color("### TCP end of stream", "yellow")) + if rfcomm_channel.state == rfcomm.DLC.State.CONNECTED: + await rfcomm_channel.disconnect() + return + + if self.tcp_tracer: + self.tcp_tracer.trace_data(data) + + rfcomm_channel.write(data) + await rfcomm_channel.drain() + except Exception as error: + print(f"!!! Exception: {error}") + break + + writer.close() + await writer.wait_closed() + print(color("~~~ Bye bye", "magenta")) + + +# ----------------------------------------------------------------------------- +class ClientBridge: + """ + RFCOMM client bridge: connects to a BR/EDR device, then waits for an inbound + TCP connection on a specified port number. When a TCP client connects, an + RFCOMM connection to the device is established, and the data is bridged in both + directions, with flow control. + When the TCP connection is closed by the client, the RFCOMM channel is + disconnected, but the connection to the device remains, ready for a new TCP client + to connect. + """ + + READ_CHUNK_SIZE = 4096 + + def __init__( + self, + channel: int, + uuid: str, + trace: bool, + address: str, + tcp_host: str, + tcp_port: int, + encrypt: bool, + ): + self.channel = channel + self.uuid = uuid + self.trace = trace + self.address = address + self.tcp_host = tcp_host + self.tcp_port = tcp_port + self.encrypt = encrypt + self.device: Optional[Device] = None + self.connection: Optional[Connection] = None + self.rfcomm_client: Optional[rfcomm.Client] + self.rfcomm_mux: Optional[rfcomm.Multiplexer] + self.tcp_connected: bool = False + + self.tcp_tracer: Optional[Tracer] + self.rfcomm_tracer: Optional[Tracer] + + if trace: + self.tcp_tracer = Tracer(color("RFCOMM->TCP", "cyan")) + self.rfcomm_tracer = Tracer(color("TCP->RFCOMM", "magenta")) + else: + self.rfcomm_tracer = None + self.tcp_tracer = None + + async def connect(self) -> None: + if self.connection: + return + + print(color(f"@@@ Connecting to Bluetooth {self.address}", "blue")) + assert self.device + self.connection = await self.device.connect( + self.address, transport=core.BT_BR_EDR_TRANSPORT + ) + print(color(f"@@@ Bluetooth connection: {self.connection}", "blue")) + + if self.encrypt: + print(color("@@@ Encrypting Bluetooth connection", "blue")) + await self.connection.encrypt() + print(color("@@@ Bluetooth connection encrypted", "blue")) + + self.rfcomm_client = rfcomm.Client(self.connection) + self.rfcomm_mux = await self.rfcomm_client.start() + + def on_disconnection(reason): + print( + color("@@@ Bluetooth disconnection:", "red"), + hci.HCI_Constant.error_name(reason), + ) + self.connection = None + + self.connection.on("disconnection", on_disconnection) + + async def start(self, device: Device) -> None: + self.device = device + + # Called when a TCP connection is established + async def on_tcp_connection(reader, writer): + print(color("<<< TCP connection", "magenta")) + if self.tcp_connected: + print( + color("!!! TCP connection already active, rejecting new one", "red") + ) + writer.close() + return + self.tcp_connected = True + + await self.pipe(reader, writer) + writer.close() + await writer.wait_closed() + + 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 pipe( + self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter + ) -> None: + # Resolve the channel number from the UUID if needed + if self.channel == 0: + await self.connect() + assert self.connection + channel = await rfcomm.find_rfcomm_channel_with_uuid( + self.connection, self.uuid + ) + if channel: + print(color(f"### Found RFCOMM channel {channel}", "yellow")) + else: + print(color(f"!!! RFCOMM channel with UUID {self.uuid} not found")) + return + else: + channel = self.channel + + # Connect a new RFCOMM channel + await self.connect() + assert self.rfcomm_mux + print(color(f'*** Opening RFCOMM channel {channel}', 'green')) + try: + rfcomm_channel = await self.rfcomm_mux.open_dlc(channel) + print(color(f'*** RFCOMM channel open: {rfcomm_channel}', "green")) + except Exception as error: + print(color(f'!!! RFCOMM open failed: {error}', 'red')) + return + + # Pipe data from RFCOMM to TCP + def on_rfcomm_channel_closed(): + print(color("*** RFCOMM channel closed", "green")) + + def write_rfcomm_data(data): + if self.trace: + self.rfcomm_tracer.trace_data(data) + + writer.write(data) + + rfcomm_channel.on("close", on_rfcomm_channel_closed) + rfcomm_channel.sink = write_rfcomm_data + + # Pipe data from TCP to RFCOMM + while True: + try: + data = await reader.read(self.READ_CHUNK_SIZE) + + if len(data) == 0: + print(color("### TCP end of stream", "yellow")) + if rfcomm_channel.state == rfcomm.DLC.State.CONNECTED: + await rfcomm_channel.disconnect() + self.tcp_connected = False + return + + if self.tcp_tracer: + self.tcp_tracer.trace_data(data) + + rfcomm_channel.write(data) + await rfcomm_channel.drain() + except Exception as error: + print(f"!!! Exception: {error}") + break + + print(color("~~~ Bye bye", "magenta")) + + +# ----------------------------------------------------------------------------- +async def run(device_config, hci_transport, bridge): + print("<<< connecting to HCI...") + async with await transport.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) + device.classic_enabled = True + + # Let's go + await device.power_on() + try: + await bridge.start(device) + + # Wait until the transport terminates + await hci_source.wait_for_termination() + except core.ConnectionError as error: + print(color(f"!!! Bluetooth connection failed: {error}", "red")) + except Exception as error: + print(f"Exception while running bridge: {error}") + + +# ----------------------------------------------------------------------------- +@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("--trace", is_flag=True, help="Trace bridged data to stdout") +@click.option("--channel", help="RFCOMM channel number", type=int, default=0) +@click.option("--uuid", help="UUID for the RFCOMM channel", default=DEFAULT_RFCOMM_UUID) +def cli( + context, + device_config, + hci_transport, + trace, + channel, + uuid, +): + context.ensure_object(dict) + context.obj["device_config"] = device_config + context.obj["hci_transport"] = hci_transport + context.obj["trace"] = trace + context.obj["channel"] = channel + context.obj["uuid"] = uuid + + +# ----------------------------------------------------------------------------- +@cli.command() +@click.pass_context +@click.option("--tcp-host", help="TCP host", default="localhost") +@click.option("--tcp-port", help="TCP port", default=DEFAULT_TCP_PORT) +def server(context, tcp_host, tcp_port): + bridge = ServerBridge( + context.obj["channel"], + context.obj["uuid"], + context.obj["trace"], + 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=DEFAULT_TCP_PORT) +@click.option("--encrypt", is_flag=True, help="Encrypt the connection") +def client(context, bluetooth_address, tcp_host, tcp_port, encrypt): + bridge = ClientBridge( + context.obj["channel"], + context.obj["uuid"], + context.obj["trace"], + bluetooth_address, + tcp_host, + tcp_port, + encrypt, + ) + 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 diff --git a/bumble/l2cap.py b/bumble/l2cap.py index cec14b85..3eef0e05 100644 --- a/bumble/l2cap.py +++ b/bumble/l2cap.py @@ -70,6 +70,7 @@ L2CAP_LE_SIGNALING_CID = 0x05 L2CAP_MIN_LE_MTU = 23 L2CAP_MIN_BR_EDR_MTU = 48 +L2CAP_MAX_BR_EDR_MTU = 65535 L2CAP_DEFAULT_MTU = 2048 # Default value for the MTU we are willing to accept diff --git a/bumble/rfcomm.py b/bumble/rfcomm.py index 1020a1ea..c95a4c78 100644 --- a/bumble/rfcomm.py +++ b/bumble/rfcomm.py @@ -446,10 +446,6 @@ class DLC(EventEmitter): DISCONNECTED = 0x04 RESET = 0x05 - connection_result: Optional[asyncio.Future] - _sink: Optional[Callable[[bytes], None]] - _enqueued_rx_packets: collections.deque[bytes] - def __init__( self, multiplexer: Multiplexer, @@ -469,12 +465,15 @@ class DLC(EventEmitter): self.state = DLC.State.INIT self.role = multiplexer.role self.c_r = 1 if self.role == Multiplexer.Role.INITIATOR else 0 - self.connection_result = None + self.connection_result: Optional[asyncio.Future] = None + self.disconnection_result: Optional[asyncio.Future] = None self.drained = asyncio.Event() self.drained.set() # Queued packets when sink is not set. - self._enqueued_rx_packets = collections.deque(maxlen=DEFAULT_RX_QUEUE_SIZE) - self._sink = None + self._enqueued_rx_packets: collections.deque[bytes] = collections.deque( + maxlen=DEFAULT_RX_QUEUE_SIZE + ) + self._sink: Optional[Callable[[bytes], None]] = None # Compute the MTU max_overhead = 4 + 1 # header with 2-byte length + fcs @@ -525,20 +524,35 @@ class DLC(EventEmitter): self.emit('open') def on_ua_frame(self, _frame: RFCOMM_Frame) -> None: - if self.state != DLC.State.CONNECTING: + if self.state == DLC.State.CONNECTING: + # Exchange the modem status with the peer + msc = RFCOMM_MCC_MSC(dlci=self.dlci, fc=0, rtc=1, rtr=1, ic=0, dv=1) + mcc = RFCOMM_Frame.make_mcc(mcc_type=MccType.MSC, 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.change_state(DLC.State.CONNECTED) + if self.connection_result: + self.connection_result.set_result(None) + self.connection_result = None + self.multiplexer.on_dlc_open_complete(self) + elif self.state == DLC.State.DISCONNECTING: + self.change_state(DLC.State.DISCONNECTED) + if self.disconnection_result: + self.disconnection_result.set_result(None) + self.disconnection_result = None + self.multiplexer.on_dlc_disconnection(self) + self.emit('close') + else: logger.warning( - color('!!! received SABM when not in CONNECTING state', 'red') + color( + ( + '!!! received UA frame when not in ' + 'CONNECTING or DISCONNECTING 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) - mcc = RFCOMM_Frame.make_mcc(mcc_type=MccType.MSC, 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.change_state(DLC.State.CONNECTED) - self.multiplexer.on_dlc_open_complete(self) def on_dm_frame(self, frame: RFCOMM_Frame) -> None: # TODO: handle all states @@ -609,6 +623,19 @@ class DLC(EventEmitter): self.connection_result = asyncio.get_running_loop().create_future() self.send_frame(RFCOMM_Frame.sabm(c_r=self.c_r, dlci=self.dlci)) + async def disconnect(self) -> None: + if self.state != DLC.State.CONNECTED: + raise InvalidStateError('invalid state') + + self.disconnection_result = asyncio.get_running_loop().create_future() + self.change_state(DLC.State.DISCONNECTING) + self.send_frame( + RFCOMM_Frame.disc( + c_r=1 if self.role == Multiplexer.Role.INITIATOR else 0, dlci=self.dlci + ) + ) + await self.disconnection_result + def accept(self) -> None: if self.state != DLC.State.INIT: raise InvalidStateError('invalid state') @@ -689,6 +716,17 @@ class DLC(EventEmitter): async def drain(self) -> None: await self.drained.wait() + def abort(self) -> None: + logger.debug(f'aborting DLC: {self}') + if self.connection_result: + self.connection_result.cancel() + self.connection_result = None + if self.disconnection_result: + self.disconnection_result.cancel() + self.disconnection_result = None + self.change_state(DLC.State.RESET) + self.emit('close') + def __str__(self) -> str: return f'DLC(dlci={self.dlci},state={self.state.name})' @@ -728,6 +766,8 @@ class Multiplexer(EventEmitter): # Become a sink for the L2CAP channel l2cap_channel.sink = self.on_pdu + l2cap_channel.on('close', self.on_l2cap_channel_close) + def change_state(self, new_state: State) -> None: logger.debug(f'{self} state change -> {color(new_state.name, "cyan")}') self.state = new_state @@ -791,6 +831,7 @@ class Multiplexer(EventEmitter): 'rfcomm', ) ) + self.open_result = None else: logger.warning(f'unexpected state for DM: {self}') @@ -915,15 +956,31 @@ class Multiplexer(EventEmitter): information=mcc, ) ) - result = await self.open_result - self.open_result = None - return result + return await self.open_result def on_dlc_open_complete(self, dlc: DLC) -> None: logger.debug(f'DLC [{dlc.dlci}] open complete') + self.change_state(Multiplexer.State.CONNECTED) + if self.open_result: self.open_result.set_result(dlc) + self.open_result = None + + def on_dlc_disconnection(self, dlc: DLC) -> None: + logger.debug(f'DLC [{dlc.dlci}] disconnection') + self.dlcs.pop(dlc.dlci, None) + + def on_l2cap_channel_close(self) -> None: + logger.debug('L2CAP channel closed, cleaning up') + if self.open_result: + self.open_result.cancel() + self.open_result = None + if self.disconnection_result: + self.disconnection_result.cancel() + self.disconnection_result = None + for dlc in self.dlcs.values(): + dlc.abort() def __str__(self) -> str: return f'Multiplexer(state={self.state.name})' diff --git a/bumble/sdp.py b/bumble/sdp.py index 35b4a3a1..543c322f 100644 --- a/bumble/sdp.py +++ b/bumble/sdp.py @@ -997,7 +997,7 @@ class Server: try: handler(sdp_pdu) except Exception as error: - logger.warning(f'{color("!!! Exception in handler:", "red")} {error}') + logger.exception(f'{color("!!! Exception in handler:", "red")} {error}') self.send_response( SDP_ErrorResponse( transaction_id=sdp_pdu.transaction_id, diff --git a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/SocketClient.kt b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/SocketClient.kt index bd5b7f4a..46a014a4 100644 --- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/SocketClient.kt +++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/SocketClient.kt @@ -56,13 +56,19 @@ class SocketClient(private val viewModel: AppViewModel, private val socket: Blue thread { socketDataSource.receive() + socket.close() + sender.abort() } Log.info("Startup delay: $DEFAULT_STARTUP_DELAY") Thread.sleep(DEFAULT_STARTUP_DELAY.toLong()); Log.info("Starting to send") - sender.run() + try { + sender.run() + } catch (error: IOException) { + Log.info("run ended abruptly") + } cleanup() } } diff --git a/setup.cfg b/setup.cfg index 05d64319..44d85415 100644 --- a/setup.cfg +++ b/setup.cfg @@ -62,6 +62,7 @@ console_scripts = bumble-gatt-dump = bumble.apps.gatt_dump:main bumble-hci-bridge = bumble.apps.hci_bridge:main bumble-l2cap-bridge = bumble.apps.l2cap_bridge:main + bumble-rfcomm-bridge = bumble.apps.rfcomm_bridge:main bumble-pair = bumble.apps.pair:main bumble-scan = bumble.apps.scan:main bumble-show = bumble.apps.show:main