typing surrport for HCI commands return parameters

Add support for RTL8761CU

.gitignore

@@ -17,3 +17,6 @@ venv/
 .venv/
 # snoop logs
 out/
+# macOS
+.DS_Store
+._*

apps/controller_info.py

@@ -34,11 +34,7 @@ from bumble.hci import (
     HCI_READ_BD_ADDR_COMMAND,
     HCI_READ_BUFFER_SIZE_COMMAND,
     HCI_READ_LOCAL_NAME_COMMAND,
-    HCI_SUCCESS,
-    CodecID,
     HCI_Command,
-    HCI_Command_Complete_Event,
-    HCI_Command_Status_Event,
     HCI_LE_Read_Buffer_Size_Command,
     HCI_LE_Read_Buffer_Size_V2_Command,
     HCI_LE_Read_Maximum_Advertising_Data_Length_Command,
@@ -59,34 +55,23 @@ from bumble.host import Host
 from bumble.transport import open_transport
 
 
-# -----------------------------------------------------------------------------
-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: Host) -> None:
     if host.supports_command(HCI_READ_BD_ADDR_COMMAND):
-        response = await host.send_command(HCI_Read_BD_ADDR_Command())
-        if command_succeeded(response):
-            print()
-            print(
-                color('Public Address:', 'yellow'),
-                response.return_parameters.bd_addr.to_string(False),
-            )
+        response1 = await host.send_sync_command(HCI_Read_BD_ADDR_Command())
+        print()
+        print(
+            color('Public Address:', 'yellow'),
+            response1.bd_addr.to_string(False),
+        )
 
     if host.supports_command(HCI_READ_LOCAL_NAME_COMMAND):
-        response = await host.send_command(HCI_Read_Local_Name_Command())
-        if command_succeeded(response):
-            print()
-            print(
-                color('Local Name:', 'yellow'),
-                map_null_terminated_utf8_string(response.return_parameters.local_name),
-            )
+        response2 = await host.send_sync_command(HCI_Read_Local_Name_Command())
+        print()
+        print(
+            color('Local Name:', 'yellow'),
+            map_null_terminated_utf8_string(response2.local_name),
+        )
 
 
 # -----------------------------------------------------------------------------
@@ -94,52 +79,50 @@ async def get_le_info(host: Host) -> None:
     print()
 
     if host.supports_command(HCI_LE_READ_NUMBER_OF_SUPPORTED_ADVERTISING_SETS_COMMAND):
-        response = await host.send_command(
+        response1 = await host.send_sync_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',
-            )
+        print(
+            color('LE Number Of Supported Advertising Sets:', 'yellow'),
+            response1.num_supported_advertising_sets,
+            '\n',
+        )
 
     if host.supports_command(HCI_LE_READ_MAXIMUM_ADVERTISING_DATA_LENGTH_COMMAND):
-        response = await host.send_command(
+        response2 = await host.send_sync_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',
-            )
+        print(
+            color('LE Maximum Advertising Data Length:', 'yellow'),
+            response2.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',
-            )
+        response3 = await host.send_sync_command(
+            HCI_LE_Read_Maximum_Data_Length_Command()
+        )
+        print(
+            color('Maximum Data Length:', 'yellow'),
+            (
+                f'tx:{response3.supported_max_tx_octets}/'
+                f'{response3.supported_max_tx_time}, '
+                f'rx:{response3.supported_max_rx_octets}/'
+                f'{response3.supported_max_rx_time}'
+            ),
+            '\n',
+        )
 
     if host.supports_command(HCI_LE_READ_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND):
-        response = await host.send_command(
+        response4 = await host.send_sync_command(
             HCI_LE_Read_Suggested_Default_Data_Length_Command()
         )
-        if command_succeeded(response):
-            print(
-                color('Suggested Default Data Length:', 'yellow'),
-                f'{response.return_parameters.suggested_max_tx_octets}/'
-                f'{response.return_parameters.suggested_max_tx_time}',
-                '\n',
-            )
+        print(
+            color('Suggested Default Data Length:', 'yellow'),
+            f'{response4.suggested_max_tx_octets}/'
+            f'{response4.suggested_max_tx_time}',
+            '\n',
+        )
 
     print(color('LE Features:', 'yellow'))
     for feature in host.supported_le_features:
@@ -151,37 +134,31 @@ async def get_flow_control_info(host: Host) -> None:
     print()
 
     if host.supports_command(HCI_READ_BUFFER_SIZE_COMMAND):
-        response = await host.send_command(
-            HCI_Read_Buffer_Size_Command(), check_result=True
-        )
+        response1 = await host.send_sync_command(HCI_Read_Buffer_Size_Command())
         print(
             color('ACL Flow Control:', 'yellow'),
-            f'{response.return_parameters.hc_total_num_acl_data_packets} '
-            f'packets of size {response.return_parameters.hc_acl_data_packet_length}',
+            f'{response1.hc_total_num_acl_data_packets} '
+            f'packets of size {response1.hc_acl_data_packet_length}',
         )
 
     if host.supports_command(HCI_LE_READ_BUFFER_SIZE_V2_COMMAND):
-        response = await host.send_command(
-            HCI_LE_Read_Buffer_Size_V2_Command(), check_result=True
-        )
+        response2 = await host.send_sync_command(HCI_LE_Read_Buffer_Size_V2_Command())
         print(
             color('LE ACL Flow Control:', 'yellow'),
-            f'{response.return_parameters.total_num_le_acl_data_packets} '
-            f'packets of size {response.return_parameters.le_acl_data_packet_length}',
+            f'{response2.total_num_le_acl_data_packets} '
+            f'packets of size {response2.le_acl_data_packet_length}',
         )
         print(
             color('LE ISO Flow Control:', 'yellow'),
-            f'{response.return_parameters.total_num_iso_data_packets} '
-            f'packets of size {response.return_parameters.iso_data_packet_length}',
+            f'{response2.total_num_iso_data_packets} '
+            f'packets of size {response2.iso_data_packet_length}',
         )
     elif host.supports_command(HCI_LE_READ_BUFFER_SIZE_COMMAND):
-        response = await host.send_command(
-            HCI_LE_Read_Buffer_Size_Command(), check_result=True
-        )
+        response3 = await host.send_sync_command(HCI_LE_Read_Buffer_Size_Command())
         print(
             color('LE ACL Flow Control:', 'yellow'),
-            f'{response.return_parameters.total_num_le_acl_data_packets} '
-            f'packets of size {response.return_parameters.le_acl_data_packet_length}',
+            f'{response3.total_num_le_acl_data_packets} '
+            f'packets of size {response3.le_acl_data_packet_length}',
         )
 
 
@@ -190,52 +167,44 @@ async def get_codecs_info(host: Host) -> None:
     print()
 
     if host.supports_command(HCI_Read_Local_Supported_Codecs_V2_Command.op_code):
-        response = await host.send_command(
-            HCI_Read_Local_Supported_Codecs_V2_Command(), check_result=True
+        response1 = await host.send_sync_command(
+            HCI_Read_Local_Supported_Codecs_V2_Command()
         )
         print(color('Codecs:', 'yellow'))
 
         for codec_id, transport in zip(
-            response.return_parameters.standard_codec_ids,
-            response.return_parameters.standard_codec_transports,
+            response1.standard_codec_ids,
+            response1.standard_codec_transports,
         ):
-            transport_name = HCI_Read_Local_Supported_Codecs_V2_Command.Transport(
-                transport
-            ).name
-            codec_name = CodecID(codec_id).name
-            print(f'  {codec_name} - {transport_name}')
+            print(f'  {codec_id.name} - {transport.name}')
 
-        for codec_id, transport in zip(
-            response.return_parameters.vendor_specific_codec_ids,
-            response.return_parameters.vendor_specific_codec_transports,
+        for vendor_codec_id, vendor_transport in zip(
+            response1.vendor_specific_codec_ids,
+            response1.vendor_specific_codec_transports,
         ):
-            transport_name = HCI_Read_Local_Supported_Codecs_V2_Command.Transport(
-                transport
-            ).name
-            company = name_or_number(COMPANY_IDENTIFIERS, codec_id >> 16)
-            print(f'  {company} / {codec_id & 0xFFFF} - {transport_name}')
+            company = name_or_number(COMPANY_IDENTIFIERS, vendor_codec_id >> 16)
+            print(f'  {company} / {vendor_codec_id & 0xFFFF} - {vendor_transport.name}')
 
-        if not response.return_parameters.standard_codec_ids:
+        if not response1.standard_codec_ids:
             print('  No standard codecs')
-        if not response.return_parameters.vendor_specific_codec_ids:
+        if not response1.vendor_specific_codec_ids:
             print('  No Vendor-specific codecs')
 
     if host.supports_command(HCI_Read_Local_Supported_Codecs_Command.op_code):
-        response = await host.send_command(
-            HCI_Read_Local_Supported_Codecs_Command(), check_result=True
+        response2 = await host.send_sync_command(
+            HCI_Read_Local_Supported_Codecs_Command()
         )
         print(color('Codecs (BR/EDR):', 'yellow'))
-        for codec_id in response.return_parameters.standard_codec_ids:
-            codec_name = CodecID(codec_id).name
-            print(f'  {codec_name}')
+        for codec_id in response2.standard_codec_ids:
+            print(f'  {codec_id.name}')
 
-        for codec_id in response.return_parameters.vendor_specific_codec_ids:
-            company = name_or_number(COMPANY_IDENTIFIERS, codec_id >> 16)
-            print(f'  {company} / {codec_id & 0xFFFF}')
+        for vendor_codec_id in response2.vendor_specific_codec_ids:
+            company = name_or_number(COMPANY_IDENTIFIERS, vendor_codec_id >> 16)
+            print(f'  {company} / {vendor_codec_id & 0xFFFF}')
 
-        if not response.return_parameters.standard_codec_ids:
+        if not response2.standard_codec_ids:
             print('  No standard codecs')
-        if not response.return_parameters.vendor_specific_codec_ids:
+        if not response2.vendor_specific_codec_ids:
             print('  No Vendor-specific codecs')
 
 

apps/controller_loopback.py

@@ -85,7 +85,7 @@ class Loopback:
             print(color('@@@ Received last packet', 'green'))
             self.done.set()
 
-    async def run(self):
+    async def run(self) -> None:
         """Run a loopback throughput test"""
         print(color('>>> Connecting to HCI...', 'green'))
         async with await open_transport(self.transport) as (
@@ -100,11 +100,15 @@ class Loopback:
             # make sure data can fit in one l2cap pdu
             l2cap_header_size = 4
 
-            max_packet_size = (
+            packet_queue = (
                 host.acl_packet_queue
                 if host.acl_packet_queue
                 else host.le_acl_packet_queue
-            ).max_packet_size - l2cap_header_size
+            )
+            if packet_queue is None:
+                print(color('!!! No packet queue', 'red'))
+                return
+            max_packet_size = packet_queue.max_packet_size - l2cap_header_size
             if self.packet_size > max_packet_size:
                 print(
                     color(
@@ -128,20 +132,18 @@ class Loopback:
             loopback_mode = LoopbackMode.LOCAL
 
             print(color('### Setting loopback mode', 'blue'))
-            await host.send_command(
+            await host.send_sync_command(
                 HCI_Write_Loopback_Mode_Command(loopback_mode=LoopbackMode.LOCAL),
-                check_result=True,
             )
 
             print(color('### Checking loopback mode', 'blue'))
-            response = await host.send_command(
-                HCI_Read_Loopback_Mode_Command(), check_result=True
-            )
-            if response.return_parameters.loopback_mode != loopback_mode:
+            response = await host.send_sync_command(HCI_Read_Loopback_Mode_Command())
+            if response.loopback_mode != loopback_mode:
                 print(color('!!! Loopback mode mismatch', 'red'))
                 return
 
             await self.connection_event.wait()
+            assert self.connection_handle is not None
             print(color('### Connected', 'cyan'))
 
             print(color('=== Start sending', 'magenta'))

apps/lea_unicast/app.py

@@ -298,6 +298,7 @@ class Speaker:
                     advertising_interval_max=25,
                     address=Address('F1:F2:F3:F4:F5:F6'),
                     identity_address_type=Address.RANDOM_DEVICE_ADDRESS,
+                    eatt_enabled=True,
                 )
 
             device_config.le_enabled = True

apps/pair.py

@@ -15,6 +15,8 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
+
 import asyncio
 import logging
 import os
@@ -63,7 +65,7 @@ POST_PAIRING_DELAY = 1
 
 # -----------------------------------------------------------------------------
 class Waiter:
-    instance = None
+    instance: Waiter | None = None
 
     def __init__(self, linger=False):
         self.done = asyncio.get_running_loop().create_future()
@@ -327,25 +329,25 @@ async def on_pairing_failure(connection, reason):
 
 # -----------------------------------------------------------------------------
 async def pair(
-    mode,
-    sc,
-    mitm,
-    bond,
-    ctkd,
-    advertising_address,
-    identity_address,
-    linger,
-    io,
-    oob,
-    prompt,
-    request,
-    print_keys,
-    keystore_file,
-    advertise_service_uuids,
-    advertise_appearance,
-    device_config,
-    hci_transport,
-    address_or_name,
+    mode: str,
+    sc: bool,
+    mitm: bool,
+    bond: bool,
+    ctkd: bool,
+    advertising_address: str,
+    identity_address: str,
+    linger: bool,
+    io: str,
+    oob: str,
+    prompt: bool,
+    request: bool,
+    print_keys: bool,
+    keystore_file: str,
+    advertise_service_uuids: str,
+    advertise_appearance: str,
+    device_config: str,
+    hci_transport: str,
+    address_or_name: str,
 ):
     Waiter.instance = Waiter(linger=linger)
 
@@ -403,6 +405,7 @@ async def pair(
         # Create an OOB context if needed
         if oob:
             our_oob_context = OobContext()
+            legacy_context: OobLegacyContext | None
             if oob == '-':
                 shared_data = None
                 legacy_context = OobLegacyContext()
@@ -661,25 +664,25 @@ class LogHandler(logging.Handler):
 @click.argument('hci_transport')
 @click.argument('address-or-name', required=False)
 def main(
-    mode,
-    sc,
-    mitm,
-    bond,
-    ctkd,
-    advertising_address,
-    identity_address,
-    linger,
-    io,
-    oob,
-    prompt,
-    request,
-    print_keys,
-    keystore_file,
-    advertise_service_uuid,
-    advertise_appearance,
-    device_config,
-    hci_transport,
-    address_or_name,
+    mode: str,
+    sc: bool,
+    mitm: bool,
+    bond: bool,
+    ctkd: bool,
+    advertising_address: str,
+    identity_address: str,
+    linger: bool,
+    io: str,
+    oob: str,
+    prompt: bool,
+    request: bool,
+    print_keys: bool,
+    keystore_file: str,
+    advertise_service_uuid: str,
+    advertise_appearance: str,
+    device_config: str,
+    hci_transport: str,
+    address_or_name: str,
 ):
     # Setup logging
     log_handler = LogHandler()

bumble/att.py

@@ -34,10 +34,13 @@ from typing import (
     TYPE_CHECKING,
     ClassVar,
     Generic,
+    TypeAlias,
     TypeVar,
 )
 
-from bumble import hci, utils
+from typing_extensions import TypeIs
+
+from bumble import hci, l2cap, utils
 from bumble.colors import color
 from bumble.core import UUID, InvalidOperationError, ProtocolError
 from bumble.hci import HCI_Object
@@ -50,6 +53,14 @@ if TYPE_CHECKING:
 
 _T = TypeVar('_T')
 
+Bearer: TypeAlias = "Connection | l2cap.LeCreditBasedChannel"
+EnhancedBearer: TypeAlias = l2cap.LeCreditBasedChannel
+
+
+def is_enhanced_bearer(bearer: Bearer) -> TypeIs[EnhancedBearer]:
+    return isinstance(bearer, EnhancedBearer)
+
+
 # -----------------------------------------------------------------------------
 # Constants
 # -----------------------------------------------------------------------------
@@ -58,6 +69,7 @@ _T = TypeVar('_T')
 
 ATT_CID = 0x04
 ATT_PSM = 0x001F
+EATT_PSM = 0x0027
 
 class Opcode(hci.SpecableEnum):
     ATT_ERROR_RESPONSE              = 0x01
@@ -780,6 +792,43 @@ class AttributeValue(Generic[_T]):
         return self._write(connection, value)
 
 
+# -----------------------------------------------------------------------------
+class AttributeValueV2(Generic[_T]):
+    '''
+    Attribute value compatible with enhanced bearers.
+
+    The only difference between AttributeValue and AttributeValueV2 is that the actual
+    bearer (ACL connection for un-enhanced bearer, L2CAP channel for enhanced bearer)
+    will be passed into read and write callbacks in V2, while in V1 it is always
+    the base ACL connection.
+
+    This is only required when attributes must distinguish bearers, otherwise normal
+    `AttributeValue` objects are also applicable in enhanced bearers.
+    '''
+
+    def __init__(
+        self,
+        read: Callable[[Bearer], Awaitable[_T]] | Callable[[Bearer], _T] | None = None,
+        write: (
+            Callable[[Bearer, _T], Awaitable[None]]
+            | Callable[[Bearer, _T], None]
+            | None
+        ) = None,
+    ):
+        self._read = read
+        self._write = write
+
+    def read(self, bearer: Bearer) -> _T | Awaitable[_T]:
+        if self._read is None:
+            raise InvalidOperationError('AttributeValue has no read function')
+        return self._read(bearer)
+
+    def write(self, bearer: Bearer, value: _T) -> Awaitable[None] | None:
+        if self._write is None:
+            raise InvalidOperationError('AttributeValue has no write function')
+        return self._write(bearer, value)
+
+
 # -----------------------------------------------------------------------------
 class Attribute(utils.EventEmitter, Generic[_T]):
     class Permissions(enum.IntFlag):
@@ -855,7 +904,8 @@ class Attribute(utils.EventEmitter, Generic[_T]):
     def decode_value(self, value: bytes) -> _T:
         return value  # type: ignore
 
-    async def read_value(self, connection: Connection) -> bytes:
+    async def read_value(self, bearer: Bearer) -> bytes:
+        connection = bearer.connection if is_enhanced_bearer(bearer) else bearer
         if (
             (self.permissions & self.READ_REQUIRES_ENCRYPTION)
             and connection is not None
@@ -890,6 +940,17 @@ class Attribute(utils.EventEmitter, Generic[_T]):
                 raise ATT_Error(
                     error_code=error.error_code, att_handle=self.handle
                 ) from error
+        elif isinstance(self.value, AttributeValueV2):
+            try:
+                read_value = self.value.read(bearer)
+                if inspect.isawaitable(read_value):
+                    value = await read_value
+                else:
+                    value = read_value
+            except ATT_Error as error:
+                raise ATT_Error(
+                    error_code=error.error_code, att_handle=self.handle
+                ) from error
         else:
             value = self.value
 
@@ -897,7 +958,8 @@ class Attribute(utils.EventEmitter, Generic[_T]):
 
         return b'' if value is None else self.encode_value(value)
 
-    async def write_value(self, connection: Connection, value: bytes) -> None:
+    async def write_value(self, bearer: Bearer, value: bytes) -> None:
+        connection = bearer.connection if is_enhanced_bearer(bearer) else bearer
         if (
             (self.permissions & self.WRITE_REQUIRES_ENCRYPTION)
             and connection is not None
@@ -931,6 +993,15 @@ class Attribute(utils.EventEmitter, Generic[_T]):
                 raise ATT_Error(
                     error_code=error.error_code, att_handle=self.handle
                 ) from error
+        elif isinstance(self.value, AttributeValueV2):
+            try:
+                result = self.value.write(bearer, decoded_value)
+                if inspect.isawaitable(result):
+                    await result
+            except ATT_Error as error:
+                raise ATT_Error(
+                    error_code=error.error_code, att_handle=self.handle
+                ) from error
         else:
             self.value = decoded_value
 

bumble/controller.py

@@ -421,7 +421,7 @@ class Controller:
                 hci.HCI_Command_Complete_Event(
                     num_hci_command_packets=1,
                     command_opcode=command.op_code,
-                    return_parameters=result,
+                    return_parameters=hci.HCI_GenericReturnParameters(data=result),
                 )
             )
 

bumble/core.py

@@ -923,7 +923,7 @@ class DeviceClass:
     # pylint: enable=line-too-long
 
     @staticmethod
-    def split_class_of_device(class_of_device):
+    def split_class_of_device(class_of_device: int) -> tuple[int, int, int]:
         # Split the bit fields of the composite class of device value into:
         # (service_classes, major_device_class, minor_device_class)
         return (

bumble/drivers/intel.py

@@ -89,51 +89,54 @@ HCI_INTEL_WRITE_BOOT_PARAMS_COMMAND = hci.hci_vendor_command_op_code(0x000E)
 hci.HCI_Command.register_commands(globals())
 
 
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_Intel_Read_Version_Command(hci.HCI_Command):
+class HCI_Intel_Read_Version_ReturnParameters(hci.HCI_StatusReturnParameters):
+    tlv: bytes = hci.field(metadata=hci.metadata('*'))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_Intel_Read_Version_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Intel_Read_Version_Command(
+    hci.HCI_SyncCommand[HCI_Intel_Read_Version_ReturnParameters]
+):
     param0: int = dataclasses.field(metadata=hci.metadata(1))
 
-    return_parameters_fields = [
-        ("status", hci.STATUS_SPEC),
-        ("tlv", "*"),
-    ]
 
-
-@hci.HCI_Command.command
+@hci.HCI_SyncCommand.sync_command(hci.HCI_StatusReturnParameters)
 @dataclasses.dataclass
-class Hci_Intel_Secure_Send_Command(hci.HCI_Command):
+class Hci_Intel_Secure_Send_Command(
+    hci.HCI_SyncCommand[hci.HCI_StatusReturnParameters]
+):
     data_type: int = dataclasses.field(metadata=hci.metadata(1))
     data: bytes = dataclasses.field(metadata=hci.metadata("*"))
 
-    return_parameters_fields = [
-        ("status", 1),
-    ]
 
-
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_Intel_Reset_Command(hci.HCI_Command):
+class HCI_Intel_Reset_ReturnParameters(hci.HCI_ReturnParameters):
+    data: bytes = hci.field(metadata=hci.metadata('*'))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_Intel_Reset_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Intel_Reset_Command(hci.HCI_SyncCommand[HCI_Intel_Reset_ReturnParameters]):
     reset_type: int = dataclasses.field(metadata=hci.metadata(1))
     patch_enable: int = dataclasses.field(metadata=hci.metadata(1))
     ddc_reload: int = dataclasses.field(metadata=hci.metadata(1))
     boot_option: int = dataclasses.field(metadata=hci.metadata(1))
     boot_address: int = dataclasses.field(metadata=hci.metadata(4))
 
-    return_parameters_fields = [
-        ("data", "*"),
-    ]
 
-
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class Hci_Intel_Write_Device_Config_Command(hci.HCI_Command):
-    data: bytes = dataclasses.field(metadata=hci.metadata("*"))
+class HCI_Intel_Write_Device_Config_ReturnParameters(hci.HCI_StatusReturnParameters):
+    params: bytes = hci.field(metadata=hci.metadata('*'))
 
-    return_parameters_fields = [
-        ("status", hci.STATUS_SPEC),
-        ("params", "*"),
-    ]
+
+@hci.HCI_SyncCommand.sync_command(HCI_Intel_Write_Device_Config_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Intel_Write_Device_Config_Command(
+    hci.HCI_SyncCommand[HCI_Intel_Write_Device_Config_ReturnParameters]
+):
+    data: bytes = dataclasses.field(metadata=hci.metadata("*"))
 
 
 # -----------------------------------------------------------------------------
@@ -402,7 +405,7 @@ class Driver(common.Driver):
             self.host.on_hci_event_packet(event)
             return
 
-        if not event.return_parameters == hci.HCI_SUCCESS:
+        if not event.return_parameters.status == hci.HCI_SUCCESS:
             raise DriverError("HCI_Command_Complete_Event error")
 
         if self.max_in_flight_firmware_load_commands != event.num_hci_command_packets:
@@ -641,8 +644,8 @@ class Driver(common.Driver):
         while ddc_data:
             ddc_len = 1 + ddc_data[0]
             ddc_payload = ddc_data[:ddc_len]
-            await self.host.send_command(
-                Hci_Intel_Write_Device_Config_Command(data=ddc_payload)
+            await self.host.send_sync_command(
+                HCI_Intel_Write_Device_Config_Command(data=ddc_payload)
             )
             ddc_data = ddc_data[ddc_len:]
 
@@ -660,31 +663,26 @@ class Driver(common.Driver):
 
     async def read_device_info(self) -> dict[ValueType, Any]:
         self.host.ready = True
-        response = await self.host.send_command(hci.HCI_Reset_Command())
-        if not (
-            isinstance(response, hci.HCI_Command_Complete_Event)
-            and response.return_parameters
-            in (hci.HCI_UNKNOWN_HCI_COMMAND_ERROR, hci.HCI_SUCCESS)
-        ):
+        response1 = await self.host.send_sync_command(
+            hci.HCI_Reset_Command(), check_status=False
+        )
+        if response1.status not in (hci.HCI_UNKNOWN_HCI_COMMAND_ERROR, hci.HCI_SUCCESS):
             # When the controller is in operational mode, the response is a
             # successful response.
             # When the controller is in bootloader mode,
             # HCI_UNKNOWN_HCI_COMMAND_ERROR is the expected response. Anything
             # else is a failure.
-            logger.warning(f"unexpected response: {response}")
+            logger.warning(f"unexpected response: {response1}")
             raise DriverError("unexpected HCI response")
 
         # Read the firmware version.
-        response = await self.host.send_command(
-            HCI_Intel_Read_Version_Command(param0=0xFF)
+        response2 = await self.host.send_sync_command(
+            HCI_Intel_Read_Version_Command(param0=0xFF), check_status=False
         )
-        if not isinstance(response, hci.HCI_Command_Complete_Event):
-            raise DriverError("unexpected HCI response")
-
-        if response.return_parameters.status != 0:  # type: ignore
+        if response2.status != 0:  # type: ignore
             raise DriverError("HCI_Intel_Read_Version_Command error")
 
-        tlvs = _parse_tlv(response.return_parameters.tlv)  # type: ignore
+        tlvs = _parse_tlv(response2.tlv)  # type: ignore
 
         # Convert the list to a dict. That's Ok here because we only expect each type
         # to appear just once.

bumble/drivers/rtk.py

@@ -16,6 +16,7 @@ Support for Realtek USB dongles.
 Based on various online bits of information, including the Linux kernel.
 (see `drivers/bluetooth/btrtl.c`)
 """
+from __future__ import annotations
 
 import asyncio
 import enum
@@ -31,10 +32,14 @@ import weakref
 # Imports
 # -----------------------------------------------------------------------------
 from dataclasses import dataclass, field
+from typing import TYPE_CHECKING
 
 from bumble import core, hci
 from bumble.drivers import common
 
+if TYPE_CHECKING:
+    from bumble.host import Host
+
 # -----------------------------------------------------------------------------
 # Logging
 # -----------------------------------------------------------------------------
@@ -77,6 +82,7 @@ class RtlProjectId(enum.IntEnum):
     PROJECT_ID_8852A = 18
     PROJECT_ID_8852B = 20
     PROJECT_ID_8852C = 25
+    PROJECT_ID_8761C = 51
 
 
 RTK_PROJECT_ID_TO_ROM = {
@@ -92,6 +98,7 @@ RTK_PROJECT_ID_TO_ROM = {
     18: RTK_ROM_LMP_8852A,
     20: RTK_ROM_LMP_8852A,
     25: RTK_ROM_LMP_8852A,
+    51: RTK_ROM_LMP_8761A,
 }
 
 # List of USB (VendorID, ProductID) for Realtek-based devices.
@@ -123,6 +130,10 @@ RTK_USB_PRODUCTS = {
     (0x2550, 0x8761),
     (0x2B89, 0x8761),
     (0x7392, 0xC611),
+    # Realtek 8761CUV
+    (0x0B05, 0x1BF6),
+    (0x0BDA, 0xC761),
+    (0x7392, 0xF611),
     # Realtek 8821AE
     (0x0B05, 0x17DC),
     (0x13D3, 0x3414),
@@ -182,23 +193,36 @@ HCI_RTK_DROP_FIRMWARE_COMMAND = hci.hci_vendor_command_op_code(0x66)
 hci.HCI_Command.register_commands(globals())
 
 
-@hci.HCI_Command.command
 @dataclass
-class HCI_RTK_Read_ROM_Version_Command(hci.HCI_Command):
-    return_parameters_fields = [("status", hci.STATUS_SPEC), ("version", 1)]
+class HCI_RTK_Read_ROM_Version_ReturnParameters(hci.HCI_StatusReturnParameters):
+    version: int = field(metadata=hci.metadata(1))
 
 
-@hci.HCI_Command.command
+@hci.HCI_SyncCommand.sync_command(HCI_RTK_Read_ROM_Version_ReturnParameters)
 @dataclass
-class HCI_RTK_Download_Command(hci.HCI_Command):
+class HCI_RTK_Read_ROM_Version_Command(
+    hci.HCI_SyncCommand[HCI_RTK_Read_ROM_Version_ReturnParameters]
+):
+    pass
+
+
+@dataclass
+class HCI_RTK_Download_ReturnParameters(hci.HCI_StatusReturnParameters):
+    index: int = field(metadata=hci.metadata(1))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_RTK_Download_ReturnParameters)
+@dataclass
+class HCI_RTK_Download_Command(hci.HCI_SyncCommand[HCI_RTK_Download_ReturnParameters]):
     index: int = field(metadata=hci.metadata(1))
     payload: bytes = field(metadata=hci.metadata(RTK_FRAGMENT_LENGTH))
-    return_parameters_fields = [("status", hci.STATUS_SPEC), ("index", 1)]
 
 
-@hci.HCI_Command.command
+@hci.HCI_SyncCommand.sync_command(hci.HCI_GenericReturnParameters)
 @dataclass
-class HCI_RTK_Drop_Firmware_Command(hci.HCI_Command):
+class HCI_RTK_Drop_Firmware_Command(
+    hci.HCI_SyncCommand[hci.HCI_GenericReturnParameters]
+):
     pass
 
 
@@ -363,6 +387,15 @@ class Driver(common.Driver):
             fw_name="rtl8761bu_fw.bin",
             config_name="rtl8761bu_config.bin",
         ),
+        # 8761CU
+        DriverInfo(
+            rom=RTK_ROM_LMP_8761A,
+            hci=(0x0E, 0x00),
+            config_needed=False,
+            has_rom_version=True,
+            fw_name="rtl8761cu_fw.bin",
+            config_name="rtl8761cu_config.bin",
+        ),
         # 8822C
         DriverInfo(
             rom=RTK_ROM_LMP_8822B,
@@ -420,9 +453,17 @@ class Driver(common.Driver):
     @staticmethod
     def find_driver_info(hci_version, hci_subversion, lmp_subversion):
         for driver_info in Driver.DRIVER_INFOS:
-            if driver_info.rom == lmp_subversion and driver_info.hci == (
-                hci_subversion,
-                hci_version,
+            if driver_info.rom == lmp_subversion and (
+                driver_info.hci
+                == (
+                    hci_subversion,
+                    hci_version,
+                )
+                or driver_info.hci
+                == (
+                    hci_subversion,
+                    0x0,
+                )
             ):
                 return driver_info
 
@@ -467,7 +508,7 @@ class Driver(common.Driver):
         return None
 
     @staticmethod
-    def check(host):
+    def check(host: Host) -> bool:
         if not host.hci_metadata:
             logger.debug("USB metadata not found")
             return False
@@ -491,41 +532,39 @@ class Driver(common.Driver):
         return True
 
     @staticmethod
-    async def get_loaded_firmware_version(host):
-        response = await host.send_command(HCI_RTK_Read_ROM_Version_Command())
+    async def get_loaded_firmware_version(host: Host) -> int | None:
+        response1 = await host.send_sync_command(
+            HCI_RTK_Read_ROM_Version_Command(), check_status=False
+        )
 
-        if response.return_parameters.status != hci.HCI_SUCCESS:
+        if response1.status != hci.HCI_SUCCESS:
             return None
 
-        response = await host.send_command(
-            hci.HCI_Read_Local_Version_Information_Command(), check_result=True
-        )
-        return (
-            response.return_parameters.hci_subversion << 16
-            | response.return_parameters.lmp_subversion
+        response2 = await host.send_sync_command(
+            hci.HCI_Read_Local_Version_Information_Command()
         )
+        return response2.hci_subversion << 16 | response2.lmp_subversion
 
     @classmethod
-    async def driver_info_for_host(cls, host):
+    async def driver_info_for_host(cls, host: Host) -> DriverInfo | None:
         try:
-            await host.send_command(
+            await host.send_sync_command(
                 hci.HCI_Reset_Command(),
-                check_result=True,
                 response_timeout=cls.POST_RESET_DELAY,
             )
             host.ready = True  # Needed to let the host know the controller is ready.
         except asyncio.exceptions.TimeoutError:
             logger.warning("timeout waiting for hci reset, retrying")
-            await host.send_command(hci.HCI_Reset_Command(), check_result=True)
+            await host.send_sync_command(hci.HCI_Reset_Command())
             host.ready = True
 
         command = hci.HCI_Read_Local_Version_Information_Command()
-        response = await host.send_command(command, check_result=True)
-        if response.command_opcode != command.op_code:
+        response = await host.send_sync_command(command, check_status=False)
+        if response.status != hci.HCI_SUCCESS:
             logger.error("failed to probe local version information")
             return None
 
-        local_version = response.return_parameters
+        local_version = response
 
         logger.debug(
             f"looking for a driver: 0x{local_version.lmp_subversion:04X} "
@@ -546,7 +585,7 @@ class Driver(common.Driver):
         return driver_info
 
     @classmethod
-    async def for_host(cls, host, force=False):
+    async def for_host(cls, host: Host, force: bool = False):
         # Check that a driver is needed for this host
         if not force and not cls.check(host):
             return None
@@ -603,13 +642,13 @@ class Driver(common.Driver):
 
     async def download_for_rtl8723b(self):
         if self.driver_info.has_rom_version:
-            response = await self.host.send_command(
-                HCI_RTK_Read_ROM_Version_Command(), check_result=True
+            response1 = await self.host.send_sync_command(
+                HCI_RTK_Read_ROM_Version_Command(), check_status=False
             )
-            if response.return_parameters.status != hci.HCI_SUCCESS:
+            if response1.status != hci.HCI_SUCCESS:
                 logger.warning("can't get ROM version")
                 return None
-            rom_version = response.return_parameters.version
+            rom_version = response1.version
             logger.debug(f"ROM version before download: {rom_version:04X}")
         else:
             rom_version = 0
@@ -644,21 +683,20 @@ class Driver(common.Driver):
             fragment_offset = fragment_index * RTK_FRAGMENT_LENGTH
             fragment = payload[fragment_offset : fragment_offset + RTK_FRAGMENT_LENGTH]
             logger.debug(f"downloading fragment {fragment_index}")
-            await self.host.send_command(
-                HCI_RTK_Download_Command(index=download_index, payload=fragment),
-                check_result=True,
+            await self.host.send_sync_command(
+                HCI_RTK_Download_Command(index=download_index, payload=fragment)
             )
 
         logger.debug("download complete!")
 
         # Read the version again
-        response = await self.host.send_command(
-            HCI_RTK_Read_ROM_Version_Command(), check_result=True
+        response2 = await self.host.send_sync_command(
+            HCI_RTK_Read_ROM_Version_Command(), check_status=False
         )
-        if response.return_parameters.status != hci.HCI_SUCCESS:
+        if response2.status != hci.HCI_SUCCESS:
             logger.warning("can't get ROM version")
         else:
-            rom_version = response.return_parameters.version
+            rom_version = response2.version
             logger.debug(f"ROM version after download: {rom_version:02X}")
 
         return firmware.version
@@ -680,7 +718,7 @@ class Driver(common.Driver):
 
     async def init_controller(self):
         await self.download_firmware()
-        await self.host.send_command(hci.HCI_Reset_Command(), check_result=True)
+        await self.host.send_sync_command(hci.HCI_Reset_Command())
         logger.info(f"loaded FW image {self.driver_info.fw_name}")
 
 

bumble/gatt.py

@@ -31,7 +31,7 @@ import struct
 from collections.abc import Iterable, Sequence
 from typing import TypeVar
 
-from bumble.att import Attribute, AttributeValue
+from bumble.att import Attribute, AttributeValue, AttributeValueV2
 from bumble.colors import color
 from bumble.core import UUID, BaseBumbleError
 
@@ -579,7 +579,7 @@ class Descriptor(Attribute):
     def __str__(self) -> str:
         if isinstance(self.value, bytes):
             value_str = self.value.hex()
-        elif isinstance(self.value, CharacteristicValue):
+        elif isinstance(self.value, (AttributeValue, AttributeValueV2)):
             value_str = '<dynamic>'
         else:
             value_str = '<...>'

bumble/gatt_client.py

@@ -26,6 +26,7 @@
 from __future__ import annotations
 
 import asyncio
+import functools
 import logging
 import struct
 from collections.abc import Callable, Iterable
@@ -35,9 +36,10 @@ from typing import (
     Any,
     Generic,
     TypeVar,
+    overload,
 )
 
-from bumble import att, core, utils
+from bumble import att, core, l2cap, utils
 from bumble.colors import color
 from bumble.core import UUID, InvalidStateError
 from bumble.gatt import (
@@ -54,12 +56,12 @@ from bumble.gatt import (
 )
 from bumble.hci import HCI_Constant
 
+if TYPE_CHECKING:
+    from bumble import device as device_module
+
 # -----------------------------------------------------------------------------
 # Typing
 # -----------------------------------------------------------------------------
-if TYPE_CHECKING:
-    from bumble.device import Connection
-
 _T = TypeVar('_T')
 
 # -----------------------------------------------------------------------------
@@ -267,8 +269,8 @@ class Client:
     pending_response: asyncio.futures.Future[att.ATT_PDU] | None
     pending_request: att.ATT_PDU | None
 
-    def __init__(self, connection: Connection) -> None:
-        self.connection = connection
+    def __init__(self, bearer: att.Bearer) -> None:
+        self.bearer = bearer
         self.mtu_exchange_done = False
         self.request_semaphore = asyncio.Semaphore(1)
         self.pending_request = None
@@ -278,21 +280,78 @@ class Client:
         self.services = []
         self.cached_values = {}
 
-        connection.on(connection.EVENT_DISCONNECTION, self.on_disconnection)
+        if att.is_enhanced_bearer(bearer):
+            bearer.on(bearer.EVENT_CLOSE, self.on_disconnection)
+            self._bearer_id = (
+                f'[0x{bearer.connection.handle:04X}|CID=0x{bearer.source_cid:04X}]'
+            )
+            # Fill the mtu.
+            bearer.on_att_mtu_update(att.ATT_DEFAULT_MTU)
+            self.connection = bearer.connection
+        else:
+            bearer.on(bearer.EVENT_DISCONNECTION, self.on_disconnection)
+            self._bearer_id = f'[0x{bearer.handle:04X}]'
+            self.connection = bearer
+
+    @overload
+    @classmethod
+    async def connect_eatt(
+        cls,
+        connection: device_module.Connection,
+        spec: l2cap.LeCreditBasedChannelSpec | None = None,
+    ) -> Client: ...
+
+    @overload
+    @classmethod
+    async def connect_eatt(
+        cls,
+        connection: device_module.Connection,
+        spec: l2cap.LeCreditBasedChannelSpec | None = None,
+        count: int = 1,
+    ) -> list[Client]: ...
+
+    @classmethod
+    async def connect_eatt(
+        cls,
+        connection: device_module.Connection,
+        spec: l2cap.LeCreditBasedChannelSpec | None = None,
+        count: int = 1,
+    ) -> list[Client] | Client:
+        channels = await connection.device.l2cap_channel_manager.create_enhanced_credit_based_channels(
+            connection,
+            spec or l2cap.LeCreditBasedChannelSpec(psm=att.EATT_PSM),
+            count,
+        )
+
+        def on_pdu(client: Client, pdu: bytes):
+            client.on_gatt_pdu(att.ATT_PDU.from_bytes(pdu))
+
+        clients = [cls(channel) for channel in channels]
+        for channel, client in zip(channels, clients):
+            channel.sink = functools.partial(on_pdu, client)
+            channel.att_mtu = att.ATT_DEFAULT_MTU
+        return clients[0] if count == 1 else clients
+
+    @property
+    def mtu(self) -> int:
+        return self.bearer.att_mtu
+
+    @mtu.setter
+    def mtu(self, value: int) -> None:
+        self.bearer.on_att_mtu_update(value)
 
     def send_gatt_pdu(self, pdu: bytes) -> None:
-        self.connection.send_l2cap_pdu(att.ATT_CID, pdu)
+        if att.is_enhanced_bearer(self.bearer):
+            self.bearer.write(pdu)
+        else:
+            self.bearer.send_l2cap_pdu(att.ATT_CID, pdu)
 
     async def send_command(self, command: att.ATT_PDU) -> None:
-        logger.debug(
-            f'GATT Command from client: [0x{self.connection.handle:04X}] {command}'
-        )
+        logger.debug(f'GATT Command from client: {self._bearer_id} {command}')
         self.send_gatt_pdu(bytes(command))
 
     async def send_request(self, request: att.ATT_PDU):
-        logger.debug(
-            f'GATT Request from client: [0x{self.connection.handle:04X}] {request}'
-        )
+        logger.debug(f'GATT Request from client: {self._bearer_id} {request}')
 
         # Wait until we can send (only one pending command at a time for the connection)
         response = None
@@ -321,10 +380,7 @@ class Client:
     def send_confirmation(
         self, confirmation: att.ATT_Handle_Value_Confirmation
     ) -> None:
-        logger.debug(
-            f'GATT Confirmation from client: [0x{self.connection.handle:04X}] '
-            f'{confirmation}'
-        )
+        logger.debug(f'GATT Confirmation from client: {self._bearer_id} {confirmation}')
         self.send_gatt_pdu(bytes(confirmation))
 
     async def request_mtu(self, mtu: int) -> int:
@@ -336,7 +392,7 @@ class Client:
 
         # We can only send one request per connection
         if self.mtu_exchange_done:
-            return self.connection.att_mtu
+            return self.mtu
 
         # Send the request
         self.mtu_exchange_done = True
@@ -347,9 +403,9 @@ class Client:
             raise att.ATT_Error(error_code=response.error_code, message=response)
 
         # Compute the final MTU
-        self.connection.att_mtu = min(mtu, response.server_rx_mtu)
+        self.mtu = min(mtu, response.server_rx_mtu)
 
-        return self.connection.att_mtu
+        return self.mtu
 
     def get_services_by_uuid(self, uuid: UUID) -> list[ServiceProxy]:
         return [service for service in self.services if service.uuid == uuid]
@@ -942,7 +998,7 @@ class Client:
         # 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.connection.att_mtu - 1:
+        if not no_long_read and len(attribute_value) == self.mtu - 1:
             logger.debug('using READ BLOB to get the rest of the value')
             offset = len(attribute_value)
             while True:
@@ -966,7 +1022,7 @@ class Client:
                 part = response.part_attribute_value
                 attribute_value += part
 
-                if len(part) < self.connection.att_mtu - 1:
+                if len(part) < self.mtu - 1:
                     break
 
                 offset += len(part)
@@ -1062,14 +1118,13 @@ class Client:
                 )
             )
 
-    def on_disconnection(self, _) -> None:
+    def on_disconnection(self, *args) -> None:
+        del args  # unused.
         if self.pending_response and not self.pending_response.done():
             self.pending_response.cancel()
 
     def on_gatt_pdu(self, att_pdu: att.ATT_PDU) -> None:
-        logger.debug(
-            f'GATT Response to client: [0x{self.connection.handle:04X}] {att_pdu}'
-        )
+        logger.debug(f'GATT Response to client: {self._bearer_id} {att_pdu}')
         if att_pdu.op_code in att.ATT_RESPONSES:
             if self.pending_request is None:
                 # Not expected!
@@ -1099,8 +1154,7 @@ class Client:
             else:
                 logger.warning(
                     color(
-                        '--- Ignoring GATT Response from '
-                        f'[0x{self.connection.handle:04X}]: ',
+                        '--- Ignoring GATT Response from ' f'{self._bearer_id}: ',
                         'red',
                     )
                     + str(att_pdu)

bumble/gatt_server.py

@@ -32,9 +32,8 @@ from collections import defaultdict
 from collections.abc import Iterable
 from typing import TYPE_CHECKING, TypeVar
 
-from bumble import att, utils
+from bumble import att, core, l2cap, utils
 from bumble.colors import color
-from bumble.core import UUID
 from bumble.gatt import (
     GATT_CHARACTERISTIC_ATTRIBUTE_TYPE,
     GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
@@ -44,14 +43,13 @@ from bumble.gatt import (
     GATT_SECONDARY_SERVICE_ATTRIBUTE_TYPE,
     Characteristic,
     CharacteristicDeclaration,
-    CharacteristicValue,
     Descriptor,
     IncludedServiceDeclaration,
     Service,
 )
 
 if TYPE_CHECKING:
-    from bumble.device import Connection, Device
+    from bumble.device import Device
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -65,6 +63,18 @@ logger = logging.getLogger(__name__)
 GATT_SERVER_DEFAULT_MAX_MTU = 517
 
 
+# -----------------------------------------------------------------------------
+# Helpers
+# -----------------------------------------------------------------------------
+
+
+def _bearer_id(bearer: att.Bearer) -> str:
+    if att.is_enhanced_bearer(bearer):
+        return f'[0x{bearer.connection.handle:04X}|CID=0x{bearer.source_cid:04X}]'
+    else:
+        return f'[0x{bearer.handle:04X}]'
+
+
 # -----------------------------------------------------------------------------
 # GATT Server
 # -----------------------------------------------------------------------------
@@ -72,9 +82,9 @@ class Server(utils.EventEmitter):
     attributes: list[att.Attribute]
     services: list[Service]
     attributes_by_handle: dict[int, att.Attribute]
-    subscribers: dict[int, dict[int, bytes]]
-    indication_semaphores: defaultdict[int, asyncio.Semaphore]
-    pending_confirmations: defaultdict[int, asyncio.futures.Future | None]
+    subscribers: dict[att.Bearer, dict[int, bytes]]
+    indication_semaphores: defaultdict[att.Bearer, asyncio.Semaphore]
+    pending_confirmations: defaultdict[att.Bearer, asyncio.futures.Future | None]
 
     EVENT_CHARACTERISTIC_SUBSCRIPTION = "characteristic_subscription"
 
@@ -96,8 +106,29 @@ class Server(utils.EventEmitter):
     def __str__(self) -> str:
         return "\n".join(map(str, self.attributes))
 
-    def send_gatt_pdu(self, connection_handle: int, pdu: bytes) -> None:
-        self.device.send_l2cap_pdu(connection_handle, att.ATT_CID, pdu)
+    def register_eatt(
+        self, spec: l2cap.LeCreditBasedChannelSpec | None = None
+    ) -> l2cap.LeCreditBasedChannelServer:
+        def on_channel(channel: l2cap.LeCreditBasedChannel):
+            logger.debug(
+                "New EATT Bearer Connection=0x%04X CID=0x%04X",
+                channel.connection.handle,
+                channel.source_cid,
+            )
+            channel.att_mtu = att.ATT_DEFAULT_MTU
+            channel.sink = lambda pdu: self.on_gatt_pdu(
+                channel, att.ATT_PDU.from_bytes(pdu)
+            )
+
+        return self.device.create_l2cap_server(
+            spec or l2cap.LeCreditBasedChannelSpec(psm=att.EATT_PSM), handler=on_channel
+        )
+
+    def send_gatt_pdu(self, bearer: att.Bearer, pdu: bytes) -> None:
+        if att.is_enhanced_bearer(bearer):
+            bearer.write(pdu)
+        else:
+            self.device.send_l2cap_pdu(bearer.handle, att.ATT_CID, pdu)
 
     def next_handle(self) -> int:
         return 1 + len(self.attributes)
@@ -138,7 +169,7 @@ class Server(utils.EventEmitter):
             None,
         )
 
-    def get_service_attribute(self, service_uuid: UUID) -> Service | None:
+    def get_service_attribute(self, service_uuid: core.UUID) -> Service | None:
         return next(
             (
                 attribute
@@ -151,7 +182,7 @@ class Server(utils.EventEmitter):
         )
 
     def get_characteristic_attributes(
-        self, service_uuid: UUID, characteristic_uuid: UUID
+        self, service_uuid: core.UUID, characteristic_uuid: core.UUID
     ) -> tuple[CharacteristicDeclaration, Characteristic] | None:
         service_handle = self.get_service_attribute(service_uuid)
         if not service_handle:
@@ -176,7 +207,10 @@ class Server(utils.EventEmitter):
         )
 
     def get_descriptor_attribute(
-        self, service_uuid: UUID, characteristic_uuid: UUID, descriptor_uuid: UUID
+        self,
+        service_uuid: core.UUID,
+        characteristic_uuid: core.UUID,
+        descriptor_uuid: core.UUID,
     ) -> Descriptor | None:
         characteristics = self.get_characteristic_attributes(
             service_uuid, characteristic_uuid
@@ -257,14 +291,7 @@ class Server(utils.EventEmitter):
                     Descriptor(
                         GATT_CLIENT_CHARACTERISTIC_CONFIGURATION_DESCRIPTOR,
                         att.Attribute.READABLE | att.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
-                            ),
-                        ),
+                        self.make_descriptor_value(characteristic),
                     )
                 )
 
@@ -280,10 +307,21 @@ class Server(utils.EventEmitter):
         for service in services:
             self.add_service(service)
 
-    def read_cccd(
-        self, connection: Connection, characteristic: Characteristic
-    ) -> bytes:
-        subscribers = self.subscribers.get(connection.handle)
+    def make_descriptor_value(
+        self, characteristic: Characteristic
+    ) -> att.AttributeValueV2:
+        # It is necessary to use Attribute Value V2 here to identify the bearer of CCCD.
+        return att.AttributeValueV2(
+            lambda bearer, characteristic=characteristic: self.read_cccd(
+                bearer, characteristic
+            ),
+            write=lambda bearer, value, characteristic=characteristic: self.write_cccd(
+                bearer, characteristic, value
+            ),
+        )
+
+    def read_cccd(self, bearer: att.Bearer, characteristic: Characteristic) -> bytes:
+        subscribers = self.subscribers.get(bearer)
         cccd = None
         if subscribers:
             cccd = subscribers.get(characteristic.handle)
@@ -292,12 +330,12 @@ class Server(utils.EventEmitter):
 
     def write_cccd(
         self,
-        connection: Connection,
+        bearer: att.Bearer,
         characteristic: Characteristic,
         value: bytes,
     ) -> None:
         logger.debug(
-            f'Subscription update for connection=0x{connection.handle:04X}, '
+            f'Subscription update for connection={_bearer_id(bearer)}, '
             f'handle=0x{characteristic.handle:04X}: {value.hex()}'
         )
 
@@ -306,41 +344,60 @@ class Server(utils.EventEmitter):
             logger.warning('CCCD value not 2 bytes long')
             return
 
-        cccds = self.subscribers.setdefault(connection.handle, {})
+        cccds = self.subscribers.setdefault(bearer, {})
         cccds[characteristic.handle] = value
         logger.debug(f'CCCDs: {cccds}')
         notify_enabled = value[0] & 0x01 != 0
         indicate_enabled = value[0] & 0x02 != 0
         characteristic.emit(
             characteristic.EVENT_SUBSCRIPTION,
-            connection,
+            bearer,
             notify_enabled,
             indicate_enabled,
         )
         self.emit(
             self.EVENT_CHARACTERISTIC_SUBSCRIPTION,
-            connection,
+            bearer,
             characteristic,
             notify_enabled,
             indicate_enabled,
         )
 
-    def send_response(self, connection: Connection, response: att.ATT_PDU) -> None:
-        logger.debug(
-            f'GATT Response from server: [0x{connection.handle:04X}] {response}'
-        )
-        self.send_gatt_pdu(connection.handle, bytes(response))
+    def send_response(self, bearer: att.Bearer, response: att.ATT_PDU) -> None:
+        logger.debug(f'GATT Response from server: {_bearer_id(bearer)} {response}')
+        self.send_gatt_pdu(bearer, bytes(response))
 
     async def notify_subscriber(
         self,
-        connection: Connection,
+        bearer: att.Bearer,
         attribute: att.Attribute,
         value: bytes | None = None,
         force: bool = False,
+    ) -> None:
+        if att.is_enhanced_bearer(bearer) or force:
+            return await self._notify_single_subscriber(bearer, attribute, value, force)
+        else:
+            # If API is called to a Connection and not forced, try to notify all subscribed bearers on it.
+            bearers = [
+                channel
+                for channel in self.device.l2cap_channel_manager.le_coc_channels.get(
+                    bearer.handle, {}
+                ).values()
+                if channel.psm == att.EATT_PSM
+            ] + [bearer]
+            for bearer in bearers:
+                await self._notify_single_subscriber(bearer, attribute, value, force)
+
+    async def _notify_single_subscriber(
+        self,
+        bearer: att.Bearer,
+        attribute: att.Attribute,
+        value: bytes | None,
+        force: bool,
     ) -> None:
         # Check if there's a subscriber
         if not force:
-            subscribers = self.subscribers.get(connection.handle)
+            subscribers = self.subscribers.get(bearer)
             if not subscribers:
                 logger.debug('not notifying, no subscribers')
                 return
@@ -356,34 +413,53 @@ class Server(utils.EventEmitter):
 
         # Get or encode the value
         value = (
-            await attribute.read_value(connection)
+            await attribute.read_value(bearer)
             if value is None
             else attribute.encode_value(value)
         )
 
         # Truncate if needed
-        if len(value) > connection.att_mtu - 3:
-            value = value[: connection.att_mtu - 3]
+        if len(value) > bearer.att_mtu - 3:
+            value = value[: bearer.att_mtu - 3]
 
         # Notify
         notification = att.ATT_Handle_Value_Notification(
             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, bytes(notification))
+        logger.debug(f'GATT Notify from server: {_bearer_id(bearer)} {notification}')
+        self.send_gatt_pdu(bearer, bytes(notification))
 
     async def indicate_subscriber(
         self,
-        connection: Connection,
+        bearer: att.Bearer,
         attribute: att.Attribute,
         value: bytes | None = None,
         force: bool = False,
+    ) -> None:
+        if att.is_enhanced_bearer(bearer) or force:
+            return await self._notify_single_subscriber(bearer, attribute, value, force)
+        else:
+            # If API is called to a Connection and not forced, try to indicate all subscribed bearers on it.
+            bearers = [
+                channel
+                for channel in self.device.l2cap_channel_manager.le_coc_channels.get(
+                    bearer.handle, {}
+                ).values()
+                if channel.psm == att.EATT_PSM
+            ] + [bearer]
+            for bearer in bearers:
+                await self._indicate_single_bearer(bearer, attribute, value, force)
+
+    async def _indicate_single_bearer(
+        self,
+        bearer: att.Bearer,
+        attribute: att.Attribute,
+        value: bytes | None,
+        force: bool,
     ) -> None:
         # Check if there's a subscriber
         if not force:
-            subscribers = self.subscribers.get(connection.handle)
+            subscribers = self.subscribers.get(bearer)
             if not subscribers:
                 logger.debug('not indicating, no subscribers')
                 return
@@ -399,40 +475,38 @@ class Server(utils.EventEmitter):
 
         # Get or encode the value
         value = (
-            await attribute.read_value(connection)
+            await attribute.read_value(bearer)
             if value is None
             else attribute.encode_value(value)
         )
 
         # Truncate if needed
-        if len(value) > connection.att_mtu - 3:
-            value = value[: connection.att_mtu - 3]
+        if len(value) > bearer.att_mtu - 3:
+            value = value[: bearer.att_mtu - 3]
 
         # Indicate
         indication = att.ATT_Handle_Value_Indication(
             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: {_bearer_id(bearer)} {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
+        async with self.indication_semaphores[bearer]:
+            assert self.pending_confirmations[bearer] is None
 
             # Create a future value to hold the eventual response
-            pending_confirmation = self.pending_confirmations[connection.handle] = (
+            pending_confirmation = self.pending_confirmations[bearer] = (
                 asyncio.get_running_loop().create_future()
             )
 
             try:
-                self.send_gatt_pdu(connection.handle, bytes(indication))
+                self.send_gatt_pdu(bearer, bytes(indication))
                 await asyncio.wait_for(pending_confirmation, GATT_REQUEST_TIMEOUT)
             except asyncio.TimeoutError as error:
                 logger.warning(color('!!! GATT Indicate timeout', 'red'))
                 raise TimeoutError(f'GATT timeout for {indication.name}') from error
             finally:
-                self.pending_confirmations[connection.handle] = None
+                self.pending_confirmations[bearer] = None
 
     async def _notify_or_indicate_subscribers(
         self,
@@ -441,24 +515,24 @@ class Server(utils.EventEmitter):
         value: bytes | None = None,
         force: bool = False,
     ) -> None:
-        # 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
+        # Get all the bearers for which there's at least one subscription
+        bearers: list[att.Bearer] = [
+            bearer
+            for bearer, subscribers in self.subscribers.items()
+            if force or subscribers.get(attribute.handle)
         ]
 
         # Indicate or notify for each connection
-        if connections:
-            coroutine = self.indicate_subscriber if indicate else self.notify_subscriber
+        if bearers:
+            coroutine = (
+                self._indicate_single_bearer
+                if indicate
+                else self._notify_single_subscriber
+            )
             await asyncio.wait(
                 [
-                    asyncio.create_task(coroutine(connection, attribute, value, force))
-                    for connection in connections
+                    asyncio.create_task(coroutine(bearer, attribute, value, force))
+                    for bearer in bearers
                 ]
             )
 
@@ -480,21 +554,18 @@ class Server(utils.EventEmitter):
     ):
         return await self._notify_or_indicate_subscribers(True, attribute, value, force)
 
-    def on_disconnection(self, connection: Connection) -> None:
-        if connection.handle in self.subscribers:
-            del self.subscribers[connection.handle]
-        if connection.handle in self.indication_semaphores:
-            del self.indication_semaphores[connection.handle]
-        if connection.handle in self.pending_confirmations:
-            del self.pending_confirmations[connection.handle]
+    def on_disconnection(self, bearer: att.Bearer) -> None:
+        self.subscribers.pop(bearer, None)
+        self.indication_semaphores.pop(bearer, None)
+        self.pending_confirmations.pop(bearer, None)
 
-    def on_gatt_pdu(self, connection: Connection, att_pdu: att.ATT_PDU) -> None:
-        logger.debug(f'GATT Request to server: [0x{connection.handle:04X}] {att_pdu}')
+    def on_gatt_pdu(self, bearer: att.Bearer, att_pdu: att.ATT_PDU) -> None:
+        logger.debug(f'GATT Request to server: {_bearer_id(bearer)} {att_pdu}')
         handler_name = f'on_{att_pdu.name.lower()}'
         handler = getattr(self, handler_name, None)
         if handler is not None:
             try:
-                handler(connection, att_pdu)
+                handler(bearer, att_pdu)
             except att.ATT_Error as error:
                 logger.debug(f'normal exception returned by handler: {error}')
                 response = att.ATT_Error_Response(
@@ -502,7 +573,7 @@ class Server(utils.EventEmitter):
                     attribute_handle_in_error=error.att_handle,
                     error_code=error.error_code,
                 )
-                self.send_response(connection, response)
+                self.send_response(bearer, response)
             except Exception:
                 logger.exception(color("!!! Exception in handler:", "red"))
                 response = att.ATT_Error_Response(
@@ -510,18 +581,18 @@ class Server(utils.EventEmitter):
                     attribute_handle_in_error=0x0000,
                     error_code=att.ATT_UNLIKELY_ERROR_ERROR,
                 )
-                self.send_response(connection, response)
+                self.send_response(bearer, response)
                 raise
         else:
             # No specific handler registered
             if att_pdu.op_code in att.ATT_REQUESTS:
                 # Invoke the generic handler
-                self.on_att_request(connection, att_pdu)
+                self.on_att_request(bearer, att_pdu)
             else:
                 # Just ignore
                 logger.warning(
                     color(
-                        f'--- Ignoring GATT Request from [0x{connection.handle:04X}]: ',
+                        f'--- Ignoring GATT Request from {_bearer_id(bearer)}: ',
                         'red',
                     )
                     + str(att_pdu)
@@ -530,13 +601,14 @@ class Server(utils.EventEmitter):
     #######################################################
     # ATT handlers
     #######################################################
-    def on_att_request(self, connection: Connection, pdu: att.ATT_PDU) -> None:
+    def on_att_request(self, bearer: att.Bearer, pdu: att.ATT_PDU) -> None:
         '''
         Handler for requests without a more specific handler
         '''
         logger.warning(
             color(
-                f'--- Unsupported ATT Request from [0x{connection.handle:04X}]: ', 'red'
+                f'--- Unsupported ATT Request from {_bearer_id(bearer)}: ',
+                'red',
             )
             + str(pdu)
         )
@@ -545,29 +617,28 @@ class Server(utils.EventEmitter):
             attribute_handle_in_error=0x0000,
             error_code=att.ATT_REQUEST_NOT_SUPPORTED_ERROR,
         )
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     def on_att_exchange_mtu_request(
-        self, connection: Connection, request: att.ATT_Exchange_MTU_Request
+        self, bearer: att.Bearer, request: att.ATT_Exchange_MTU_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.2.1 Exchange MTU Request
         '''
         self.send_response(
-            connection, att.ATT_Exchange_MTU_Response(server_rx_mtu=self.max_mtu)
+            bearer, att.ATT_Exchange_MTU_Response(server_rx_mtu=self.max_mtu)
         )
 
         # Compute the final MTU
         if request.client_rx_mtu >= att.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)
+            bearer.on_att_mtu_update(mtu)
         else:
             logger.warning('invalid client_rx_mtu received, MTU not changed')
 
     def on_att_find_information_request(
-        self, connection: Connection, request: att.ATT_Find_Information_Request
+        self, bearer: att.Bearer, request: att.ATT_Find_Information_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.3.1 Find Information Request
@@ -580,7 +651,7 @@ class Server(utils.EventEmitter):
             or request.starting_handle > request.ending_handle
         ):
             self.send_response(
-                connection,
+                bearer,
                 att.ATT_Error_Response(
                     request_opcode_in_error=request.op_code,
                     attribute_handle_in_error=request.starting_handle,
@@ -590,7 +661,7 @@ class Server(utils.EventEmitter):
             return
 
         # Build list of returned attributes
-        pdu_space_available = connection.att_mtu - 2
+        pdu_space_available = bearer.att_mtu - 2
         attributes: list[att.Attribute] = []
         uuid_size = 0
         for attribute in (
@@ -632,18 +703,18 @@ class Server(utils.EventEmitter):
                 error_code=att.ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_find_by_type_value_request(
-        self, connection: Connection, request: att.ATT_Find_By_Type_Value_Request
+        self, bearer: att.Bearer, request: att.ATT_Find_By_Type_Value_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.3.3 Find By Type Value Request
         '''
 
         # Build list of returned attributes
-        pdu_space_available = connection.att_mtu - 2
+        pdu_space_available = bearer.att_mtu - 2
         attributes = []
         response: att.ATT_PDU
         async for attribute in (
@@ -652,7 +723,7 @@ class Server(utils.EventEmitter):
             if attribute.handle >= request.starting_handle
             and attribute.handle <= request.ending_handle
             and attribute.type == request.attribute_type
-            and (await attribute.read_value(connection)) == request.attribute_value
+            and (await attribute.read_value(bearer)) == request.attribute_value
             and pdu_space_available >= 4
         ):
             # TODO: check permissions
@@ -688,17 +759,17 @@ class Server(utils.EventEmitter):
                 error_code=att.ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_read_by_type_request(
-        self, connection: Connection, request: att.ATT_Read_By_Type_Request
+        self, bearer: att.Bearer, request: att.ATT_Read_By_Type_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.4.1 Read By Type Request
         '''
 
-        pdu_space_available = connection.att_mtu - 2
+        pdu_space_available = bearer.att_mtu - 2
 
         response: att.ATT_PDU = att.ATT_Error_Response(
             request_opcode_in_error=request.op_code,
@@ -716,7 +787,7 @@ class Server(utils.EventEmitter):
             and pdu_space_available
         ):
             try:
-                attribute_value = await attribute.read_value(connection)
+                attribute_value = await attribute.read_value(bearer)
             except att.ATT_Error as error:
                 # If the first attribute is unreadable, return an error
                 # Otherwise return attributes up to this point
@@ -729,7 +800,7 @@ class Server(utils.EventEmitter):
                 break
 
             # Check the attribute value size
-            max_attribute_size = min(connection.att_mtu - 4, 253)
+            max_attribute_size = min(bearer.att_mtu - 4, 253)
             if len(attribute_value) > max_attribute_size:
                 # We need to truncate
                 attribute_value = attribute_value[:max_attribute_size]
@@ -756,11 +827,11 @@ class Server(utils.EventEmitter):
         else:
             logging.debug(f"not found {request}")
 
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_read_request(
-        self, connection: Connection, request: att.ATT_Read_Request
+        self, bearer: att.Bearer, request: att.ATT_Read_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.4.3 Read Request
@@ -769,7 +840,7 @@ class Server(utils.EventEmitter):
         response: att.ATT_PDU
         if attribute := self.get_attribute(request.attribute_handle):
             try:
-                value = await attribute.read_value(connection)
+                value = await attribute.read_value(bearer)
             except att.ATT_Error as error:
                 response = att.ATT_Error_Response(
                     request_opcode_in_error=request.op_code,
@@ -777,7 +848,7 @@ class Server(utils.EventEmitter):
                     error_code=error.error_code,
                 )
             else:
-                value_size = min(connection.att_mtu - 1, len(value))
+                value_size = min(bearer.att_mtu - 1, len(value))
                 response = att.ATT_Read_Response(attribute_value=value[:value_size])
         else:
             response = att.ATT_Error_Response(
@@ -785,11 +856,11 @@ class Server(utils.EventEmitter):
                 attribute_handle_in_error=request.attribute_handle,
                 error_code=att.ATT_INVALID_HANDLE_ERROR,
             )
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_read_blob_request(
-        self, connection: Connection, request: att.ATT_Read_Blob_Request
+        self, bearer: att.Bearer, request: att.ATT_Read_Blob_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.4.5 Read Blob Request
@@ -798,7 +869,7 @@ class Server(utils.EventEmitter):
         response: att.ATT_PDU
         if attribute := self.get_attribute(request.attribute_handle):
             try:
-                value = await attribute.read_value(connection)
+                value = await attribute.read_value(bearer)
             except att.ATT_Error as error:
                 response = att.ATT_Error_Response(
                     request_opcode_in_error=request.op_code,
@@ -812,7 +883,7 @@ class Server(utils.EventEmitter):
                         attribute_handle_in_error=request.attribute_handle,
                         error_code=att.ATT_INVALID_OFFSET_ERROR,
                     )
-                elif len(value) <= connection.att_mtu - 1:
+                elif len(value) <= bearer.att_mtu - 1:
                     response = att.ATT_Error_Response(
                         request_opcode_in_error=request.op_code,
                         attribute_handle_in_error=request.attribute_handle,
@@ -820,7 +891,7 @@ class Server(utils.EventEmitter):
                     )
                 else:
                     part_size = min(
-                        connection.att_mtu - 1, len(value) - request.value_offset
+                        bearer.att_mtu - 1, len(value) - request.value_offset
                     )
                     response = att.ATT_Read_Blob_Response(
                         part_attribute_value=value[
@@ -833,11 +904,11 @@ class Server(utils.EventEmitter):
                 attribute_handle_in_error=request.attribute_handle,
                 error_code=att.ATT_INVALID_HANDLE_ERROR,
             )
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_read_by_group_type_request(
-        self, connection: Connection, request: att.ATT_Read_By_Group_Type_Request
+        self, bearer: att.Bearer, request: att.ATT_Read_By_Group_Type_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.4.9 Read by Group Type Request
@@ -852,10 +923,10 @@ class Server(utils.EventEmitter):
                 attribute_handle_in_error=request.starting_handle,
                 error_code=att.ATT_UNSUPPORTED_GROUP_TYPE_ERROR,
             )
-            self.send_response(connection, response)
+            self.send_response(bearer, response)
             return
 
-        pdu_space_available = connection.att_mtu - 2
+        pdu_space_available = bearer.att_mtu - 2
         attributes: list[tuple[int, int, bytes]] = []
         for attribute in (
             attribute
@@ -867,9 +938,9 @@ class Server(utils.EventEmitter):
         ):
             # No need to catch permission errors here, since these attributes
             # must all be world-readable
-            attribute_value = await attribute.read_value(connection)
+            attribute_value = await attribute.read_value(bearer)
             # Check the attribute value size
-            max_attribute_size = min(connection.att_mtu - 6, 251)
+            max_attribute_size = min(bearer.att_mtu - 6, 251)
             if len(attribute_value) > max_attribute_size:
                 # We need to truncate
                 attribute_value = attribute_value[:max_attribute_size]
@@ -904,11 +975,11 @@ class Server(utils.EventEmitter):
                 error_code=att.ATT_ATTRIBUTE_NOT_FOUND_ERROR,
             )
 
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_write_request(
-        self, connection: Connection, request: att.ATT_Write_Request
+        self, bearer: att.Bearer, request: att.ATT_Write_Request
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.5.1 Write Request
@@ -918,7 +989,7 @@ class Server(utils.EventEmitter):
         attribute = self.get_attribute(request.attribute_handle)
         if attribute is None:
             self.send_response(
-                connection,
+                bearer,
                 att.ATT_Error_Response(
                     request_opcode_in_error=request.op_code,
                     attribute_handle_in_error=request.attribute_handle,
@@ -932,7 +1003,7 @@ class Server(utils.EventEmitter):
         # Check the request parameters
         if len(request.attribute_value) > GATT_MAX_ATTRIBUTE_VALUE_SIZE:
             self.send_response(
-                connection,
+                bearer,
                 att.ATT_Error_Response(
                     request_opcode_in_error=request.op_code,
                     attribute_handle_in_error=request.attribute_handle,
@@ -944,7 +1015,7 @@ class Server(utils.EventEmitter):
         response: att.ATT_PDU
         try:
             # Accept the value
-            await attribute.write_value(connection, request.attribute_value)
+            await attribute.write_value(bearer, request.attribute_value)
         except att.ATT_Error as error:
             response = att.ATT_Error_Response(
                 request_opcode_in_error=request.op_code,
@@ -954,11 +1025,11 @@ class Server(utils.EventEmitter):
         else:
             # Done
             response = att.ATT_Write_Response()
-        self.send_response(connection, response)
+        self.send_response(bearer, response)
 
     @utils.AsyncRunner.run_in_task()
     async def on_att_write_command(
-        self, connection: Connection, request: att.ATT_Write_Command
+        self, bearer: att.Bearer, request: att.ATT_Write_Command
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.5.3 Write Command
@@ -977,22 +1048,20 @@ class Server(utils.EventEmitter):
 
         # Accept the value
         try:
-            await attribute.write_value(connection, request.attribute_value)
+            await attribute.write_value(bearer, request.attribute_value)
         except Exception:
             logger.exception('!!! ignoring exception')
 
     def on_att_handle_value_confirmation(
         self,
-        connection: Connection,
+        bearer: att.Bearer,
         confirmation: att.ATT_Handle_Value_Confirmation,
     ):
         '''
         See Bluetooth spec Vol 3, Part F - 3.4.7.3 Handle Value Confirmation
         '''
         del confirmation  # Unused.
-        if (
-            pending_confirmation := self.pending_confirmations[connection.handle]
-        ) is None:
+        if (pending_confirmation := self.pending_confirmations[bearer]) is None:
             # Not expected!
             logger.warning(
                 '!!! unexpected confirmation, there is no pending indication'

bumble/host.py

@@ -23,11 +23,15 @@ import dataclasses
 import logging
 import struct
 from collections.abc import Awaitable, Callable
-from typing import TYPE_CHECKING, Any, cast
+from typing import TYPE_CHECKING, Any, TypeVar, cast, overload
 
 from bumble import drivers, hci, utils
 from bumble.colors import color
-from bumble.core import ConnectionPHY, InvalidStateError, PhysicalTransport
+from bumble.core import (
+    ConnectionPHY,
+    InvalidStateError,
+    PhysicalTransport,
+)
 from bumble.l2cap import L2CAP_PDU
 from bumble.snoop import Snooper
 from bumble.transport.common import TransportLostError
@@ -35,7 +39,6 @@ from bumble.transport.common import TransportLostError
 if TYPE_CHECKING:
     from bumble.transport.common import TransportSink, TransportSource
 
-
 # -----------------------------------------------------------------------------
 # Logging
 # -----------------------------------------------------------------------------
@@ -236,6 +239,9 @@ class IsoLink:
 
 
 # -----------------------------------------------------------------------------
+_RP = TypeVar('_RP', bound=hci.HCI_ReturnParameters)
+
+
 class Host(utils.EventEmitter):
     connections: dict[int, Connection]
     cis_links: dict[int, IsoLink]
@@ -264,11 +270,13 @@ class Host(utils.EventEmitter):
         self.bis_links = {}  # BIS links, by connection handle
         self.sco_links = {}  # SCO links, by connection handle
         self.bigs = {}  # BIG Handle to BIS Handles
-        self.pending_command = None
+        self.pending_command: hci.HCI_SyncCommand | hci.HCI_AsyncCommand | None = None
         self.pending_response: asyncio.Future[Any] | None = None
         self.number_of_supported_advertising_sets = 0
         self.maximum_advertising_data_length = 31
-        self.local_version = None
+        self.local_version: (
+            hci.HCI_Read_Local_Version_Information_ReturnParameters | None
+        ) = None
         self.local_supported_commands = 0
         self.local_le_features = 0
         self.local_lmp_features = hci.LmpFeatureMask(0)  # Classic LMP features
@@ -312,7 +320,7 @@ class Host(utils.EventEmitter):
         self.emit('flush')
         self.command_semaphore.release()
 
-    async def reset(self, driver_factory=drivers.get_driver_for_host):
+    async def reset(self, driver_factory=drivers.get_driver_for_host) -> None:
         if self.ready:
             self.ready = False
             await self.flush()
@@ -330,57 +338,53 @@ class Host(utils.EventEmitter):
 
         # Send a reset command unless a driver has already done so.
         if reset_needed:
-            await self.send_command(hci.HCI_Reset_Command(), check_result=True)
+            await self.send_sync_command(hci.HCI_Reset_Command())
             self.ready = True
 
-        response = await self.send_command(
-            hci.HCI_Read_Local_Supported_Commands_Command(), check_result=True
+        response1 = await self.send_sync_command(
+            hci.HCI_Read_Local_Supported_Commands_Command()
         )
         self.local_supported_commands = int.from_bytes(
-            response.return_parameters.supported_commands, 'little'
+            response1.supported_commands, 'little'
         )
 
         if self.supports_command(hci.HCI_LE_READ_LOCAL_SUPPORTED_FEATURES_COMMAND):
-            response = await self.send_command(
-                hci.HCI_LE_Read_Local_Supported_Features_Command(), check_result=True
+            response2 = await self.send_sync_command(
+                hci.HCI_LE_Read_Local_Supported_Features_Command()
             )
-            self.local_le_features = struct.unpack(
-                '<Q', response.return_parameters.le_features
-            )[0]
+            self.local_le_features = struct.unpack('<Q', response2.le_features)[0]
 
         if self.supports_command(hci.HCI_READ_LOCAL_VERSION_INFORMATION_COMMAND):
-            response = await self.send_command(
-                hci.HCI_Read_Local_Version_Information_Command(), check_result=True
+            self.local_version = await self.send_sync_command(
+                hci.HCI_Read_Local_Version_Information_Command()
             )
-            self.local_version = response.return_parameters
 
         if self.supports_command(hci.HCI_READ_LOCAL_EXTENDED_FEATURES_COMMAND):
             max_page_number = 0
             page_number = 0
             lmp_features = 0
             while page_number <= max_page_number:
-                response = await self.send_command(
+                response4 = await self.send_sync_command(
                     hci.HCI_Read_Local_Extended_Features_Command(
                         page_number=page_number
-                    ),
-                    check_result=True,
+                    )
                 )
                 lmp_features |= int.from_bytes(
-                    response.return_parameters.extended_lmp_features, 'little'
+                    response4.extended_lmp_features, 'little'
                 ) << (64 * page_number)
-                max_page_number = response.return_parameters.maximum_page_number
+                max_page_number = response4.maximum_page_number
                 page_number += 1
             self.local_lmp_features = hci.LmpFeatureMask(lmp_features)
 
         elif self.supports_command(hci.HCI_READ_LOCAL_SUPPORTED_FEATURES_COMMAND):
-            response = await self.send_command(
-                hci.HCI_Read_Local_Supported_Features_Command(), check_result=True
+            response5 = await self.send_sync_command(
+                hci.HCI_Read_Local_Supported_Features_Command()
             )
             self.local_lmp_features = hci.LmpFeatureMask(
-                int.from_bytes(response.return_parameters.lmp_features, 'little')
+                int.from_bytes(response5.lmp_features, 'little')
             )
 
-        await self.send_command(
+        await self.send_sync_command(
             hci.HCI_Set_Event_Mask_Command(
                 event_mask=hci.HCI_Set_Event_Mask_Command.mask(
                     [
@@ -437,7 +441,7 @@ class Host(utils.EventEmitter):
             )
         )
         if self.supports_command(hci.HCI_SET_EVENT_MASK_PAGE_2_COMMAND):
-            await self.send_command(
+            await self.send_sync_command(
                 hci.HCI_Set_Event_Mask_Page_2_Command(
                     event_mask_page_2=hci.HCI_Set_Event_Mask_Page_2_Command.mask(
                         [hci.HCI_ENCRYPTION_CHANGE_V2_EVENT]
@@ -499,20 +503,14 @@ class Host(utils.EventEmitter):
                 ]
             )
 
-        await self.send_command(
+        await self.send_sync_command(
             hci.HCI_LE_Set_Event_Mask_Command(le_event_mask=le_event_mask)
         )
 
         if self.supports_command(hci.HCI_READ_BUFFER_SIZE_COMMAND):
-            response = await self.send_command(
-                hci.HCI_Read_Buffer_Size_Command(), check_result=True
-            )
-            hc_acl_data_packet_length = (
-                response.return_parameters.hc_acl_data_packet_length
-            )
-            hc_total_num_acl_data_packets = (
-                response.return_parameters.hc_total_num_acl_data_packets
-            )
+            response6 = await self.send_sync_command(hci.HCI_Read_Buffer_Size_Command())
+            hc_acl_data_packet_length = response6.hc_acl_data_packet_length
+            hc_total_num_acl_data_packets = response6.hc_total_num_acl_data_packets
 
             logger.debug(
                 'HCI ACL flow control: '
@@ -531,19 +529,13 @@ class Host(utils.EventEmitter):
         iso_data_packet_length = 0
         total_num_iso_data_packets = 0
         if self.supports_command(hci.HCI_LE_READ_BUFFER_SIZE_V2_COMMAND):
-            response = await self.send_command(
-                hci.HCI_LE_Read_Buffer_Size_V2_Command(), check_result=True
-            )
-            le_acl_data_packet_length = (
-                response.return_parameters.le_acl_data_packet_length
-            )
-            total_num_le_acl_data_packets = (
-                response.return_parameters.total_num_le_acl_data_packets
-            )
-            iso_data_packet_length = response.return_parameters.iso_data_packet_length
-            total_num_iso_data_packets = (
-                response.return_parameters.total_num_iso_data_packets
+            response7 = await self.send_sync_command(
+                hci.HCI_LE_Read_Buffer_Size_V2_Command()
             )
+            le_acl_data_packet_length = response7.le_acl_data_packet_length
+            total_num_le_acl_data_packets = response7.total_num_le_acl_data_packets
+            iso_data_packet_length = response7.iso_data_packet_length
+            total_num_iso_data_packets = response7.total_num_iso_data_packets
 
             logger.debug(
                 'HCI LE flow control: '
@@ -553,15 +545,11 @@ class Host(utils.EventEmitter):
                 f'total_num_iso_data_packets={total_num_iso_data_packets}'
             )
         elif self.supports_command(hci.HCI_LE_READ_BUFFER_SIZE_COMMAND):
-            response = await self.send_command(
-                hci.HCI_LE_Read_Buffer_Size_Command(), check_result=True
-            )
-            le_acl_data_packet_length = (
-                response.return_parameters.le_acl_data_packet_length
-            )
-            total_num_le_acl_data_packets = (
-                response.return_parameters.total_num_le_acl_data_packets
+            response8 = await self.send_sync_command(
+                hci.HCI_LE_Read_Buffer_Size_Command()
             )
+            le_acl_data_packet_length = response8.le_acl_data_packet_length
+            total_num_le_acl_data_packets = response8.total_num_le_acl_data_packets
 
             logger.debug(
                 'HCI LE ACL flow control: '
@@ -592,16 +580,16 @@ class Host(utils.EventEmitter):
         ) and self.supports_command(
             hci.HCI_LE_WRITE_SUGGESTED_DEFAULT_DATA_LENGTH_COMMAND
         ):
-            response = await self.send_command(
+            response9 = await self.send_sync_command(
                 hci.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
+            suggested_max_tx_octets = response9.suggested_max_tx_octets
+            suggested_max_tx_time = response9.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(
+                await self.send_sync_command(
                     hci.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,
@@ -611,23 +599,21 @@ class Host(utils.EventEmitter):
         if self.supports_command(
             hci.HCI_LE_READ_NUMBER_OF_SUPPORTED_ADVERTISING_SETS_COMMAND
         ):
-            response = await self.send_command(
-                hci.HCI_LE_Read_Number_Of_Supported_Advertising_Sets_Command(),
-                check_result=True,
+            response10 = await self.send_sync_command(
+                hci.HCI_LE_Read_Number_Of_Supported_Advertising_Sets_Command()
             )
             self.number_of_supported_advertising_sets = (
-                response.return_parameters.num_supported_advertising_sets
+                response10.num_supported_advertising_sets
             )
 
         if self.supports_command(
             hci.HCI_LE_READ_MAXIMUM_ADVERTISING_DATA_LENGTH_COMMAND
         ):
-            response = await self.send_command(
-                hci.HCI_LE_Read_Maximum_Advertising_Data_Length_Command(),
-                check_result=True,
+            response11 = await self.send_sync_command(
+                hci.HCI_LE_Read_Maximum_Advertising_Data_Length_Command()
             )
             self.maximum_advertising_data_length = (
-                response.return_parameters.max_advertising_data_length
+                response11.max_advertising_data_length
             )
 
     @property
@@ -654,9 +640,11 @@ class Host(utils.EventEmitter):
         if self.hci_sink:
             self.hci_sink.on_packet(bytes(packet))
 
-    async def send_command(
-        self, command, check_result=False, response_timeout: int | None = None
-    ):
+    async def _send_command(
+        self,
+        command: hci.HCI_SyncCommand | hci.HCI_AsyncCommand,
+        response_timeout: float | None = None,
+    ) -> hci.HCI_Command_Complete_Event | hci.HCI_Command_Status_Event:
         # Wait until we can send (only one pending command at a time)
         async with self.command_semaphore:
             assert self.pending_command is None
@@ -668,29 +656,9 @@ class Host(utils.EventEmitter):
 
             try:
                 self.send_hci_packet(command)
-                await asyncio.wait_for(self.pending_response, timeout=response_timeout)
-                response = self.pending_response.result()
-
-                # Check the return parameters if required
-                if check_result:
-                    if isinstance(response, hci.HCI_Command_Status_Event):
-                        status = response.status  # type: ignore[attr-defined]
-                    elif 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.HCI_SUCCESS:
-                        logger.warning(
-                            f'{command.name} failed '
-                            f'({hci.HCI_Constant.error_name(status)})'
-                        )
-                        raise hci.HCI_Error(status)
-
-                return response
+                return await asyncio.wait_for(
+                    self.pending_response, timeout=response_timeout
+                )
             except Exception:
                 logger.exception(color("!!! Exception while sending command:", "red"))
                 raise
@@ -698,12 +666,107 @@ class Host(utils.EventEmitter):
                 self.pending_command = None
                 self.pending_response = None
 
-    # Use this method to send a command from a task
-    def send_command_sync(self, command: hci.HCI_Command) -> None:
-        async def send_command(command: hci.HCI_Command) -> None:
-            await self.send_command(command)
+    @overload
+    async def send_command(
+        self,
+        command: hci.HCI_SyncCommand[_RP],
+        check_result: bool = False,
+        response_timeout: float | None = None,
+    ) -> hci.HCI_Command_Complete_Event[_RP]: ...
 
-        asyncio.create_task(send_command(command))
+    @overload
+    async def send_command(
+        self,
+        command: hci.HCI_AsyncCommand,
+        check_result: bool = False,
+        response_timeout: float | None = None,
+    ) -> hci.HCI_Command_Status_Event: ...
+
+    async def send_command(
+        self,
+        command: hci.HCI_SyncCommand[_RP] | hci.HCI_AsyncCommand,
+        check_result: bool = False,
+        response_timeout: float | None = None,
+    ) -> hci.HCI_Command_Complete_Event[_RP] | hci.HCI_Command_Status_Event:
+        response = await self._send_command(command, response_timeout)
+
+        # Check the return parameters if required
+        if check_result:
+            if isinstance(response, hci.HCI_Command_Status_Event):
+                status = response.status  # type: ignore[attr-defined]
+            elif 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]
+            elif isinstance(
+                response.return_parameters, hci.HCI_GenericReturnParameters
+            ):
+                # FIXME: temporary workaround
+                # NO STATUS
+                status = hci.HCI_SUCCESS
+            else:
+                status = response.return_parameters.status
+
+            if status != hci.HCI_SUCCESS:
+                logger.warning(
+                    f'{command.name} failed ' f'({hci.HCI_Constant.error_name(status)})'
+                )
+                raise hci.HCI_Error(status)
+
+        return response
+
+    async def send_sync_command(
+        self,
+        command: hci.HCI_SyncCommand[_RP],
+        check_status: bool = True,
+        response_timeout: float | None = None,
+    ) -> _RP:
+        response = await self._send_command(command, response_timeout)
+
+        # Check that the response is of the expected type
+        assert isinstance(response, hci.HCI_Command_Complete_Event)
+        return_parameters: _RP = response.return_parameters
+        assert isinstance(return_parameters, command.return_parameters_class)
+
+        # Check the return parameters if required
+        if check_status:
+            if isinstance(return_parameters, hci.HCI_StatusReturnParameters):
+                status = return_parameters.status
+                if status != hci.HCI_SUCCESS:
+                    logger.warning(
+                        f'{command.name} failed '
+                        f'({hci.HCI_Constant.error_name(status)})'
+                    )
+                    raise hci.HCI_Error(status)
+
+        return return_parameters
+
+    async def send_async_command(
+        self,
+        command: hci.HCI_AsyncCommand,
+        check_status: bool = True,
+        response_timeout: float | None = None,
+    ) -> hci.HCI_ErrorCode:
+        response = await self._send_command(command, response_timeout)
+
+        # Check that the response is of the expected type
+        assert isinstance(response, hci.HCI_Command_Status_Event)
+
+        # Check the return parameters if required
+        status = response.status
+        if check_status:
+            if status != hci.HCI_CommandStatus.PENDING:
+                logger.warning(
+                    f'{command.name} failed ' f'({hci.HCI_Constant.error_name(status)})'
+                )
+                raise hci.HCI_Error(status)
+
+        return hci.HCI_ErrorCode(status)
+
+    @utils.deprecated("Use utils.AsyncRunner.spawn() instead.")
+    def send_command_sync(self, command: hci.HCI_AsyncCommand) -> None:
+        utils.AsyncRunner.spawn(self.send_async_command(command))
 
     def send_acl_sdu(self, connection_handle: int, sdu: bytes) -> None:
         if not (connection := self.connections.get(connection_handle)):
@@ -1338,15 +1401,17 @@ class Host(utils.EventEmitter):
 
         # For now, just accept everything
         # TODO: delegate the decision
-        self.send_command_sync(
-            hci.HCI_LE_Remote_Connection_Parameter_Request_Reply_Command(
-                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,
+        utils.AsyncRunner.spawn(
+            self.send_sync_command(
+                hci.HCI_LE_Remote_Connection_Parameter_Request_Reply_Command(
+                    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,
+                )
             )
         )
 
@@ -1382,9 +1447,9 @@ class Host(utils.EventEmitter):
                     connection_handle=event.connection_handle
                 )
 
-            await self.send_command(response)
+            await self.send_sync_command(response)
 
-        asyncio.create_task(send_long_term_key())
+        utils.AsyncRunner.spawn(send_long_term_key())
 
     def on_hci_synchronous_connection_complete_event(
         self, event: hci.HCI_Synchronous_Connection_Complete_Event
@@ -1583,9 +1648,9 @@ class Host(utils.EventEmitter):
                     bd_addr=event.bd_addr
                 )
 
-            await self.send_command(response)
+            await self.send_sync_command(response)
 
-        asyncio.create_task(send_link_key())
+        utils.AsyncRunner.spawn(send_link_key())
 
     def on_hci_io_capability_request_event(
         self, event: hci.HCI_IO_Capability_Request_Event

bumble/l2cap.py

@@ -20,6 +20,7 @@ from __future__ import annotations
 import asyncio
 import dataclasses
 import enum
+import itertools
 import logging
 import struct
 from collections import deque
@@ -302,11 +303,9 @@ class EnhancedControlField(ControlField):
 
 @dataclasses.dataclass
 class InformationEnhancedControlField(EnhancedControlField):
-    tx_seq: int = 0
+    tx_seq: int
+    sar: int
     req_seq: int = 0
-    segmentation_and_reassembly: int = (
-        EnhancedControlField.SegmentationAndReassembly.UNSEGMENTED
-    )
     final: int = 1
 
     frame_type = EnhancedControlField.FieldType.I_FRAME
@@ -316,15 +315,15 @@ class InformationEnhancedControlField(EnhancedControlField):
         return cls(
             tx_seq=(data[0] >> 1) & 0b0111111,
             final=(data[0] >> 7) & 0b1,
-            req_seq=(data[1] & 0b001111111),
-            segmentation_and_reassembly=(data[1] >> 6) & 0b11,
+            req_seq=(data[1] & 0b00111111),
+            sar=(data[1] >> 6) & 0b11,
         )
 
     def __bytes__(self) -> bytes:
         return bytes(
             [
                 self.frame_type | (self.tx_seq << 1) | (self.final << 7),
-                self.req_seq | (self.segmentation_and_reassembly << 6),
+                self.req_seq | (self.sar << 6),
             ]
         )
 
@@ -889,27 +888,38 @@ class EnhancedRetransmissionProcessor(Processor):
     class _PendingPdu:
         payload: bytes
         tx_seq: int
+        sar: InformationEnhancedControlField.SegmentationAndReassembly
+        sdu_length: int = 0
         req_seq: int = 0
 
         def __bytes__(self) -> bytes:
             return (
                 bytes(
                     InformationEnhancedControlField(
-                        tx_seq=self.tx_seq, req_seq=self.req_seq
+                        tx_seq=self.tx_seq,
+                        req_seq=self.req_seq,
+                        sar=self.sar,
                     )
                 )
+                + (
+                    struct.pack('<H', self.sdu_length)
+                    if self.sar
+                    == InformationEnhancedControlField.SegmentationAndReassembly.START
+                    else b''
+                )
                 + self.payload
             )
 
-    _expected_ack_seq: int = 0
+    _last_acked_tx_seq: int = 0
+    _last_acked_rx_seq: int = 0
     _next_tx_seq: int = 0
-    _last_tx_seq: int = 0
     _req_seq_num: int = 0
-    _next_seq_num: int = 0
     _remote_is_busy: bool = False
+    _in_sdu: bytes = b''
 
     _num_receiver_ready_polls_sent: int = 0
     _pending_pdus: list[_PendingPdu]
+    _tx_window: list[_PendingPdu]
     _monitor_handle: asyncio.TimerHandle | None = None
     _receiver_ready_poll_handle: asyncio.TimerHandle | None = None
 
@@ -917,12 +927,6 @@ class EnhancedRetransmissionProcessor(Processor):
     monitor_timeout: float
     retransmission_timeout: float
 
-    @classmethod
-    def _num_frames_between(cls, low: int, high: int) -> int:
-        if high < low:
-            high += cls.MAX_SEQ_NUM
-        return high - low
-
     def __init__(
         self,
         channel: ClassicChannel,
@@ -935,6 +939,7 @@ class EnhancedRetransmissionProcessor(Processor):
         self.peer_mps = peer_mps
         self.peer_tx_window_size = peer_tx_window_size
         self._pending_pdus = []
+        self._tx_window = []
         self.monitor_timeout = spec.monitor_timeout
         self.channel = channel
         self.retransmission_timeout = spec.retransmission_timeout
@@ -972,12 +977,9 @@ class EnhancedRetransmissionProcessor(Processor):
 
     def _send_receiver_ready_poll(self) -> None:
         self._num_receiver_ready_polls_sent += 1
-        self.channel.send_pdu(
-            SupervisoryEnhancedControlField(
-                supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
-                final=1,
-                req_seq=self._next_seq_num,
-            )
+        self._send_s_frame(
+            supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
+            final=1,
         )
 
     def _get_next_tx_seq(self) -> int:
@@ -987,12 +989,35 @@ class EnhancedRetransmissionProcessor(Processor):
 
     @override
     def send_sdu(self, sdu: bytes) -> None:
-        if len(sdu) > self.peer_mps:
-            raise InvalidArgumentError(
-                f'SDU size({len(sdu)}) exceeds channel MPS {self.peer_mps}'
+        if len(sdu) <= self.peer_mps:
+            pdu = self._PendingPdu(
+                payload=sdu,
+                tx_seq=self._get_next_tx_seq(),
+                req_seq=self._req_seq_num,
+                sar=InformationEnhancedControlField.SegmentationAndReassembly.UNSEGMENTED,
             )
-        pdu = self._PendingPdu(payload=sdu, tx_seq=self._get_next_tx_seq())
-        self._pending_pdus.append(pdu)
+            self._pending_pdus.append(pdu)
+        else:
+            for offset in range(0, len(sdu), self.peer_mps):
+                payload = sdu[offset : offset + self.peer_mps]
+                if offset == 0:
+                    sar = (
+                        InformationEnhancedControlField.SegmentationAndReassembly.START
+                    )
+                elif offset + len(payload) >= len(sdu):
+                    sar = InformationEnhancedControlField.SegmentationAndReassembly.END
+                else:
+                    sar = (
+                        InformationEnhancedControlField.SegmentationAndReassembly.CONTINUATION
+                    )
+                pdu = self._PendingPdu(
+                    payload=payload,
+                    tx_seq=self._get_next_tx_seq(),
+                    req_seq=self._req_seq_num,
+                    sar=sar,
+                    sdu_length=len(sdu),
+                )
+                self._pending_pdus.append(pdu)
         self._process_output()
 
     @override
@@ -1000,17 +1025,37 @@ class EnhancedRetransmissionProcessor(Processor):
         control_field = EnhancedControlField.from_bytes(pdu)
         self._update_ack_seq(control_field.req_seq, control_field.final != 0)
         if isinstance(control_field, InformationEnhancedControlField):
-            if control_field.tx_seq != self._next_seq_num:
+            if control_field.tx_seq != self._req_seq_num:
+                logger.error(
+                    "tx_seq != self._req_seq_num, tx_seq: %d, self._req_seq_num: %d",
+                    control_field.tx_seq,
+                    self._req_seq_num,
+                )
                 return
-            self._next_seq_num = (self._next_seq_num + 1) % self.MAX_SEQ_NUM
-            self._req_seq_num = self._next_seq_num
+            self._req_seq_num = (control_field.tx_seq + 1) % self.MAX_SEQ_NUM
 
-            ack_frame = SupervisoryEnhancedControlField(
-                supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
-                req_seq=self._next_seq_num,
-            )
-            self.channel.send_pdu(ack_frame)
-            self.channel.on_sdu(pdu[2:])
+            if (
+                control_field.sar
+                == InformationEnhancedControlField.SegmentationAndReassembly.START
+            ):
+                # Drop Control Field(2) + SDU Length(2)
+                self._in_sdu += pdu[4:]
+            else:
+                # Drop Control Field(2)
+                self._in_sdu += pdu[2:]
+            if control_field.sar in (
+                InformationEnhancedControlField.SegmentationAndReassembly.END,
+                InformationEnhancedControlField.SegmentationAndReassembly.UNSEGMENTED,
+            ):
+                self.channel.on_sdu(self._in_sdu)
+                self._in_sdu = b''
+
+            # If sink doesn't trigger any I-frame, ack this frame.
+            if self._req_seq_num != self._last_acked_rx_seq:
+                self._send_s_frame(
+                    supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
+                    final=0,
+                )
         elif isinstance(control_field, SupervisoryEnhancedControlField):
             self._remote_is_busy = (
                 control_field.supervision_function
@@ -1022,56 +1067,66 @@ class EnhancedRetransmissionProcessor(Processor):
                 SupervisoryEnhancedControlField.SupervisoryFunction.RNR,
             ):
                 if control_field.poll:
-                    self.channel.send_pdu(
-                        SupervisoryEnhancedControlField(
-                            supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
-                            final=1,
-                            req_seq=self._next_seq_num,
-                        )
+                    self._send_s_frame(
+                        supervision_function=SupervisoryEnhancedControlField.SupervisoryFunction.RR,
+                        final=1,
                     )
             else:
                 # TODO: Handle Retransmission.
                 pass
 
     def _process_output(self) -> None:
-        if self._remote_is_busy or self._monitor_handle:
+        if self._remote_is_busy:
+            logger.debug("Remote is busy")
+            return
+        if self._monitor_handle:
+            logger.debug("Monitor handle is not None")
             return
 
-        for pdu in self._pending_pdus:
-            if self._num_unacked_frames >= self.peer_tx_window_size:
-                return
-            self._send_pdu(pdu)
-            self._last_tx_seq = pdu.tx_seq
+        pdu_to_send = self.peer_tx_window_size - len(self._tx_window)
+        for pdu in itertools.islice(self._pending_pdus, pdu_to_send):
+            self._send_i_frame(pdu)
+        self._pending_pdus = self._pending_pdus[pdu_to_send:]
 
-    @property
-    def _num_unacked_frames(self) -> int:
-        if not self._pending_pdus:
-            return 0
-        return self._num_frames_between(self._expected_ack_seq, self._last_tx_seq + 1)
-
-    def _send_pdu(self, pdu: _PendingPdu) -> None:
+    def _send_i_frame(self, pdu: _PendingPdu) -> None:
         pdu.req_seq = self._req_seq_num
 
         self._start_receiver_ready_poll()
+        self._tx_window.append(pdu)
         self.channel.send_pdu(bytes(pdu))
+        self._last_acked_rx_seq = self._req_seq_num
+
+    def _send_s_frame(
+        self,
+        supervision_function: SupervisoryEnhancedControlField.SupervisoryFunction,
+        final: int,
+    ) -> None:
+        self.channel.send_pdu(
+            SupervisoryEnhancedControlField(
+                supervision_function=supervision_function,
+                final=final,
+                req_seq=self._req_seq_num,
+            )
+        )
+        self._last_acked_rx_seq = self._req_seq_num
 
     def _update_ack_seq(self, new_seq: int, is_poll_response: bool) -> None:
-        num_frames_acked = self._num_frames_between(self._expected_ack_seq, new_seq)
-        if num_frames_acked > self._num_unacked_frames:
+        num_frames_acked = (new_seq - self._last_acked_tx_seq) % self.MAX_SEQ_NUM
+        if num_frames_acked > len(self._tx_window):
             logger.error(
                 "Received acknowledgment for %d frames but only %d frames are pending",
                 num_frames_acked,
-                self._num_unacked_frames,
+                len(self._tx_window),
             )
             return
         if is_poll_response and self._monitor_handle:
             self._monitor_handle.cancel()
             self._monitor_handle = None
 
-        del self._pending_pdus[:num_frames_acked]
-        self._expected_ack_seq = new_seq
+        del self._tx_window[:num_frames_acked]
+        self._last_acked_tx_seq = new_seq
         if (
-            self._expected_ack_seq == self._next_tx_seq
+            self._last_acked_tx_seq == self._next_tx_seq
             and self._receiver_ready_poll_handle
         ):
             self._receiver_ready_poll_handle.cancel()
@@ -1552,6 +1607,7 @@ class LeCreditBasedChannel(utils.EventEmitter):
 
     EVENT_OPEN = "open"
     EVENT_CLOSE = "close"
+    EVENT_ATT_MTU_UPDATE = "att_mtu_update"
 
     def __init__(
         self,
@@ -1591,6 +1647,7 @@ class LeCreditBasedChannel(utils.EventEmitter):
         self.connection_result = None
         self.disconnection_result = None
         self.drained = asyncio.Event()
+        self.att_mtu = 0  # Filled by GATT client or server later.
 
         self.drained.set()
 
@@ -1821,6 +1878,10 @@ class LeCreditBasedChannel(utils.EventEmitter):
             self.disconnection_result.set_result(None)
             self.disconnection_result = None
 
+    def on_att_mtu_update(self, mtu: int) -> None:
+        self.att_mtu = mtu
+        self.emit(self.EVENT_ATT_MTU_UPDATE, mtu)
+
     def flush_output(self) -> None:
         self.out_queue.clear()
         self.out_sdu = None

bumble/profiles/battery_service.py

@@ -16,35 +16,28 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from collections.abc import Callable
 
-from bumble.gatt import (
-    GATT_BATTERY_LEVEL_CHARACTERISTIC,
-    GATT_BATTERY_SERVICE,
-    Characteristic,
-    CharacteristicValue,
-    TemplateService,
-)
-from bumble.gatt_adapters import (
-    PackedCharacteristicAdapter,
-    PackedCharacteristicProxyAdapter,
-)
-from bumble.gatt_client import CharacteristicProxy, ProfileServiceProxy
+from bumble import device, gatt, gatt_adapters, gatt_client
 
 
 # -----------------------------------------------------------------------------
-class BatteryService(TemplateService):
-    UUID = GATT_BATTERY_SERVICE
+class BatteryService(gatt.TemplateService):
+    UUID = gatt.GATT_BATTERY_SERVICE
     BATTERY_LEVEL_FORMAT = 'B'
 
-    battery_level_characteristic: Characteristic[int]
+    battery_level_characteristic: gatt.Characteristic[int]
 
-    def __init__(self, read_battery_level):
-        self.battery_level_characteristic = PackedCharacteristicAdapter(
-            Characteristic(
-                GATT_BATTERY_LEVEL_CHARACTERISTIC,
-                Characteristic.Properties.READ | Characteristic.Properties.NOTIFY,
-                Characteristic.READABLE,
-                CharacteristicValue(read=read_battery_level),
+    def __init__(self, read_battery_level: Callable[[device.Connection], int]) -> None:
+        self.battery_level_characteristic = gatt_adapters.PackedCharacteristicAdapter(
+            gatt.Characteristic(
+                gatt.GATT_BATTERY_LEVEL_CHARACTERISTIC,
+                properties=(
+                    gatt.Characteristic.Properties.READ
+                    | gatt.Characteristic.Properties.NOTIFY
+                ),
+                permissions=gatt.Characteristic.READABLE,
+                value=gatt.CharacteristicValue(read=read_battery_level),
             ),
             pack_format=BatteryService.BATTERY_LEVEL_FORMAT,
         )
@@ -52,19 +45,17 @@ class BatteryService(TemplateService):
 
 
 # -----------------------------------------------------------------------------
-class BatteryServiceProxy(ProfileServiceProxy):
+class BatteryServiceProxy(gatt_client.ProfileServiceProxy):
     SERVICE_CLASS = BatteryService
 
-    battery_level: CharacteristicProxy[int] | None
+    battery_level: gatt_client.CharacteristicProxy[int]
 
-    def __init__(self, service_proxy):
+    def __init__(self, service_proxy: gatt_client.ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(
-            GATT_BATTERY_LEVEL_CHARACTERISTIC
-        ):
-            self.battery_level = PackedCharacteristicProxyAdapter(
-                characteristics[0], pack_format=BatteryService.BATTERY_LEVEL_FORMAT
-            )
-        else:
-            self.battery_level = None
+        self.battery_level = gatt_adapters.PackedCharacteristicProxyAdapter(
+            service_proxy.get_required_characteristic_by_uuid(
+                gatt.GATT_BATTERY_LEVEL_CHARACTERISTIC
+            ),
+            pack_format=BatteryService.BATTERY_LEVEL_FORMAT,
+        )

bumble/profiles/heart_rate_service.py

@@ -18,40 +18,30 @@
 # -----------------------------------------------------------------------------
 from __future__ import annotations
 
+import dataclasses
+import enum
 import struct
-from enum import IntEnum
+from collections.abc import Callable, Sequence
+from typing import Any
 
-from bumble import core
-from bumble.att import ATT_Error
-from bumble.gatt import (
-    GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC,
-    GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC,
-    GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
-    GATT_HEART_RATE_SERVICE,
-    Characteristic,
-    CharacteristicValue,
-    TemplateService,
-)
-from bumble.gatt_adapters import (
-    DelegatedCharacteristicAdapter,
-    PackedCharacteristicAdapter,
-    SerializableCharacteristicAdapter,
-)
-from bumble.gatt_client import CharacteristicProxy, ProfileServiceProxy
+from typing_extensions import Self
+
+from bumble import att, core, device, gatt, gatt_adapters, gatt_client, utils
 
 
 # -----------------------------------------------------------------------------
-class HeartRateService(TemplateService):
-    UUID = GATT_HEART_RATE_SERVICE
+class HeartRateService(gatt.TemplateService):
+    UUID = gatt.GATT_HEART_RATE_SERVICE
+
     HEART_RATE_CONTROL_POINT_FORMAT = 'B'
     CONTROL_POINT_NOT_SUPPORTED = 0x80
     RESET_ENERGY_EXPENDED = 0x01
 
-    heart_rate_measurement_characteristic: Characteristic[HeartRateMeasurement]
-    body_sensor_location_characteristic: Characteristic[BodySensorLocation]
-    heart_rate_control_point_characteristic: Characteristic[int]
+    heart_rate_measurement_characteristic: gatt.Characteristic[HeartRateMeasurement]
+    body_sensor_location_characteristic: gatt.Characteristic[BodySensorLocation]
+    heart_rate_control_point_characteristic: gatt.Characteristic[int]
 
-    class BodySensorLocation(IntEnum):
+    class BodySensorLocation(utils.OpenIntEnum):
         OTHER = 0
         CHEST = 1
         WRIST = 2
@@ -60,82 +50,90 @@ class HeartRateService(TemplateService):
         EAR_LOBE = 5
         FOOT = 6
 
+    @dataclasses.dataclass
     class HeartRateMeasurement:
-        def __init__(
-            self,
-            heart_rate,
-            sensor_contact_detected=None,
-            energy_expended=None,
-            rr_intervals=None,
-        ):
-            if heart_rate < 0 or heart_rate > 0xFFFF:
+        heart_rate: int
+        sensor_contact_detected: bool | None = None
+        energy_expended: int | None = None
+        rr_intervals: Sequence[float] | None = None
+
+        class Flag(enum.IntFlag):
+            INT16_HEART_RATE = 1 << 0
+            SENSOR_CONTACT_DETECTED = 1 << 1
+            SENSOR_CONTACT_SUPPORTED = 1 << 2
+            ENERGY_EXPENDED_STATUS = 1 << 3
+            RR_INTERVAL = 1 << 4
+
+        def __post_init__(self) -> None:
+            if self.heart_rate < 0 or self.heart_rate > 0xFFFF:
                 raise core.InvalidArgumentError('heart_rate out of range')
 
-            if energy_expended is not None and (
-                energy_expended < 0 or energy_expended > 0xFFFF
+            if self.energy_expended is not None and (
+                self.energy_expended < 0 or self.energy_expended > 0xFFFF
             ):
                 raise core.InvalidArgumentError('energy_expended out of range')
 
-            if rr_intervals:
-                for rr_interval in rr_intervals:
+            if self.rr_intervals:
+                for rr_interval in self.rr_intervals:
                     if rr_interval < 0 or rr_interval * 1024 > 0xFFFF:
                         raise core.InvalidArgumentError('rr_intervals out of range')
 
-            self.heart_rate = heart_rate
-            self.sensor_contact_detected = sensor_contact_detected
-            self.energy_expended = energy_expended
-            self.rr_intervals = rr_intervals
-
         @classmethod
-        def from_bytes(cls, data):
+        def from_bytes(cls, data: bytes) -> Self:
             flags = data[0]
             offset = 1
 
-            if flags & 1:
-                hr = struct.unpack_from('<H', data, offset)[0]
+            if flags & cls.Flag.INT16_HEART_RATE:
+                heart_rate = struct.unpack_from('<H', data, offset)[0]
                 offset += 2
             else:
-                hr = struct.unpack_from('B', data, offset)[0]
+                heart_rate = struct.unpack_from('B', data, offset)[0]
                 offset += 1
 
-            if flags & (1 << 2):
-                sensor_contact_detected = flags & (1 << 1) != 0
+            if flags & cls.Flag.SENSOR_CONTACT_SUPPORTED:
+                sensor_contact_detected = flags & cls.Flag.SENSOR_CONTACT_DETECTED != 0
             else:
                 sensor_contact_detected = None
 
-            if flags & (1 << 3):
+            if flags & cls.Flag.ENERGY_EXPENDED_STATUS:
                 energy_expended = struct.unpack_from('<H', data, offset)[0]
                 offset += 2
             else:
                 energy_expended = None
 
-            if flags & (1 << 4):
+            rr_intervals: Sequence[float] | None = None
+            if flags & cls.Flag.RR_INTERVAL:
                 rr_intervals = tuple(
-                    struct.unpack_from('<H', data, offset + i * 2)[0] / 1024
-                    for i in range((len(data) - offset) // 2)
+                    struct.unpack_from('<H', data, i)[0] / 1024
+                    for i in range(offset, len(data), 2)
                 )
-            else:
-                rr_intervals = ()
 
-            return cls(hr, sensor_contact_detected, energy_expended, rr_intervals)
+            return cls(
+                heart_rate=heart_rate,
+                sensor_contact_detected=sensor_contact_detected,
+                energy_expended=energy_expended,
+                rr_intervals=rr_intervals,
+            )
 
-        def __bytes__(self):
+        def __bytes__(self) -> bytes:
+            flags = 0
             if self.heart_rate < 256:
-                flags = 0
                 data = struct.pack('B', self.heart_rate)
             else:
-                flags = 1
+                flags |= self.Flag.INT16_HEART_RATE
                 data = struct.pack('<H', self.heart_rate)
 
             if self.sensor_contact_detected is not None:
-                flags |= ((1 if self.sensor_contact_detected else 0) << 1) | (1 << 2)
+                flags |= self.Flag.SENSOR_CONTACT_SUPPORTED
+                if self.sensor_contact_detected:
+                    flags |= self.Flag.SENSOR_CONTACT_DETECTED
 
             if self.energy_expended is not None:
-                flags |= 1 << 3
+                flags |= self.Flag.ENERGY_EXPENDED_STATUS
                 data += struct.pack('<H', self.energy_expended)
 
-            if self.rr_intervals:
-                flags |= 1 << 4
+            if self.rr_intervals is not None:
+                flags |= self.Flag.RR_INTERVAL
                 data += b''.join(
                     [
                         struct.pack('<H', int(rr_interval * 1024))
@@ -145,57 +143,67 @@ class HeartRateService(TemplateService):
 
             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},'
-                f' rr_intervals={self.rr_intervals})'
-            )
-
     def __init__(
         self,
-        read_heart_rate_measurement,
-        body_sensor_location=None,
-        reset_energy_expended=None,
+        read_heart_rate_measurement: Callable[
+            [device.Connection], HeartRateMeasurement
+        ],
+        body_sensor_location: HeartRateService.BodySensorLocation | None = None,
+        reset_energy_expended: Callable[[device.Connection], Any] | None = None,
     ):
-        self.heart_rate_measurement_characteristic = SerializableCharacteristicAdapter(
-            Characteristic(
-                GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
-                Characteristic.Properties.NOTIFY,
-                0,
-                CharacteristicValue(read=read_heart_rate_measurement),
-            ),
-            HeartRateService.HeartRateMeasurement,
+        self.heart_rate_measurement_characteristic = (
+            gatt_adapters.SerializableCharacteristicAdapter(
+                gatt.Characteristic(
+                    uuid=gatt.GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
+                    properties=gatt.Characteristic.Properties.NOTIFY,
+                    permissions=gatt.Characteristic.Permissions(0),
+                    value=gatt.CharacteristicValue(read=read_heart_rate_measurement),
+                ),
+                HeartRateService.HeartRateMeasurement,
+            )
         )
-        characteristics = [self.heart_rate_measurement_characteristic]
+        characteristics: list[gatt.Characteristic] = [
+            self.heart_rate_measurement_characteristic
+        ]
 
         if body_sensor_location is not None:
-            self.body_sensor_location_characteristic = Characteristic(
-                GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC,
-                Characteristic.Properties.READ,
-                Characteristic.READABLE,
-                bytes([int(body_sensor_location)]),
+            self.body_sensor_location_characteristic = (
+                gatt_adapters.EnumCharacteristicAdapter(
+                    gatt.Characteristic(
+                        uuid=gatt.GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC,
+                        properties=gatt.Characteristic.Properties.READ,
+                        permissions=gatt.Characteristic.READABLE,
+                        value=body_sensor_location,
+                    ),
+                    cls=self.BodySensorLocation,
+                    length=1,
+                )
             )
             characteristics.append(self.body_sensor_location_characteristic)
 
         if reset_energy_expended:
 
-            def write_heart_rate_control_point_value(connection, value):
+            def write_heart_rate_control_point_value(
+                connection: device.Connection, value: bytes
+            ) -> None:
                 if value == self.RESET_ENERGY_EXPENDED:
                     if reset_energy_expended is not None:
                         reset_energy_expended(connection)
                 else:
-                    raise ATT_Error(self.CONTROL_POINT_NOT_SUPPORTED)
+                    raise att.ATT_Error(self.CONTROL_POINT_NOT_SUPPORTED)
 
-            self.heart_rate_control_point_characteristic = PackedCharacteristicAdapter(
-                Characteristic(
-                    GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC,
-                    Characteristic.Properties.WRITE,
-                    Characteristic.WRITEABLE,
-                    CharacteristicValue(write=write_heart_rate_control_point_value),
-                ),
-                pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
+            self.heart_rate_control_point_characteristic = (
+                gatt_adapters.PackedCharacteristicAdapter(
+                    gatt.Characteristic(
+                        uuid=gatt.GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC,
+                        properties=gatt.Characteristic.Properties.WRITE,
+                        permissions=gatt.Characteristic.WRITEABLE,
+                        value=gatt.CharacteristicValue(
+                            write=write_heart_rate_control_point_value
+                        ),
+                    ),
+                    pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
+                )
             )
             characteristics.append(self.heart_rate_control_point_characteristic)
 
@@ -203,50 +211,51 @@ class HeartRateService(TemplateService):
 
 
 # -----------------------------------------------------------------------------
-class HeartRateServiceProxy(ProfileServiceProxy):
+class HeartRateServiceProxy(gatt_client.ProfileServiceProxy):
     SERVICE_CLASS = HeartRateService
 
-    heart_rate_measurement: (
-        CharacteristicProxy[HeartRateService.HeartRateMeasurement] | None
-    )
+    heart_rate_measurement: gatt_client.CharacteristicProxy[
+        HeartRateService.HeartRateMeasurement
+    ]
     body_sensor_location: (
-        CharacteristicProxy[HeartRateService.BodySensorLocation] | None
+        gatt_client.CharacteristicProxy[HeartRateService.BodySensorLocation] | None
     )
-    heart_rate_control_point: CharacteristicProxy[int] | None
+    heart_rate_control_point: gatt_client.CharacteristicProxy[int] | None
 
-    def __init__(self, service_proxy):
+    def __init__(self, service_proxy: gatt_client.ServiceProxy) -> None:
         self.service_proxy = service_proxy
 
-        if characteristics := service_proxy.get_characteristics_by_uuid(
-            GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC
-        ):
-            self.heart_rate_measurement = SerializableCharacteristicAdapter(
-                characteristics[0], HeartRateService.HeartRateMeasurement
+        self.heart_rate_measurement = (
+            gatt_adapters.SerializableCharacteristicProxyAdapter(
+                service_proxy.get_required_characteristic_by_uuid(
+                    gatt.GATT_HEART_RATE_MEASUREMENT_CHARACTERISTIC
+                ),
+                HeartRateService.HeartRateMeasurement,
             )
-        else:
-            self.heart_rate_measurement = None
+        )
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
-            GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC
+            gatt.GATT_BODY_SENSOR_LOCATION_CHARACTERISTIC
         ):
-            self.body_sensor_location = DelegatedCharacteristicAdapter(
-                characteristics[0],
-                decode=lambda value: HeartRateService.BodySensorLocation(value[0]),
+            self.body_sensor_location = gatt_adapters.EnumCharacteristicProxyAdapter(
+                characteristics[0], cls=HeartRateService.BodySensorLocation, length=1
             )
         else:
             self.body_sensor_location = None
 
         if characteristics := service_proxy.get_characteristics_by_uuid(
-            GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC
+            gatt.GATT_HEART_RATE_CONTROL_POINT_CHARACTERISTIC
         ):
-            self.heart_rate_control_point = PackedCharacteristicAdapter(
-                characteristics[0],
-                pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
+            self.heart_rate_control_point = (
+                gatt_adapters.PackedCharacteristicProxyAdapter(
+                    characteristics[0],
+                    pack_format=HeartRateService.HEART_RATE_CONTROL_POINT_FORMAT,
+                )
             )
         else:
             self.heart_rate_control_point = None
 
-    async def reset_energy_expended(self):
+    async def reset_energy_expended(self) -> None:
         if self.heart_rate_control_point is not None:
             return await self.heart_rate_control_point.write_value(
                 HeartRateService.RESET_ENERGY_EXPENDED

bumble/vendor/android/hci.py

@@ -43,44 +43,53 @@ hci.HCI_Command.register_commands(globals())
 
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_LE_Get_Vendor_Capabilities_Command(hci.HCI_Command):
+class HCI_LE_Get_Vendor_Capabilities_ReturnParameters(hci.HCI_StatusReturnParameters):
+    max_advt_instances: int = field(metadata=hci.metadata(1), default=0)
+    offloaded_resolution_of_private_address: int = field(
+        metadata=hci.metadata(1), default=0
+    )
+    total_scan_results_storage: int = field(metadata=hci.metadata(2), default=0)
+    max_irk_list_sz: int = field(metadata=hci.metadata(1), default=0)
+    filtering_support: int = field(metadata=hci.metadata(1), default=0)
+    max_filter: int = field(metadata=hci.metadata(1), default=0)
+    activity_energy_info_support: int = field(metadata=hci.metadata(1), default=0)
+    version_supported: int = field(metadata=hci.metadata(2), default=0)
+    total_num_of_advt_tracked: int = field(metadata=hci.metadata(2), default=0)
+    extended_scan_support: int = field(metadata=hci.metadata(1), default=0)
+    debug_logging_supported: int = field(metadata=hci.metadata(1), default=0)
+    le_address_generation_offloading_support: int = field(
+        metadata=hci.metadata(1), default=0
+    )
+    a2dp_source_offload_capability_mask: int = field(
+        metadata=hci.metadata(4), default=0
+    )
+    bluetooth_quality_report_support: int = field(metadata=hci.metadata(1), default=0)
+    dynamic_audio_buffer_support: int = field(metadata=hci.metadata(4), default=0)
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_LE_Get_Vendor_Capabilities_ReturnParameters)
+@dataclasses.dataclass
+class HCI_LE_Get_Vendor_Capabilities_Command(
+    hci.HCI_SyncCommand[HCI_LE_Get_Vendor_Capabilities_ReturnParameters]
+):
     # pylint: disable=line-too-long
     '''
     See https://source.android.com/docs/core/connect/bluetooth/hci_requirements#vendor-specific-capabilities
     '''
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('max_advt_instances', 1),
-        ('offloaded_resolution_of_private_address', 1),
-        ('total_scan_results_storage', 2),
-        ('max_irk_list_sz', 1),
-        ('filtering_support', 1),
-        ('max_filter', 1),
-        ('activity_energy_info_support', 1),
-        ('version_supported', 2),
-        ('total_num_of_advt_tracked', 2),
-        ('extended_scan_support', 1),
-        ('debug_logging_supported', 1),
-        ('le_address_generation_offloading_support', 1),
-        ('a2dp_source_offload_capability_mask', 4),
-        ('bluetooth_quality_report_support', 1),
-        ('dynamic_audio_buffer_support', 4),
-    ]
-
     @classmethod
     def parse_return_parameters(cls, parameters):
         # There are many versions of this data structure, so we need to parse until
-        # there are no more bytes to parse, and leave un-signal parameters set to
-        # None (older versions)
-        nones = {field: None for field, _ in cls.return_parameters_fields}
-        return_parameters = hci.HCI_Object(cls.return_parameters_fields, **nones)
+        # there are no more bytes to parse, and leave un-signaled parameters set to
+        # 0
+        return_parameters = HCI_LE_Get_Vendor_Capabilities_ReturnParameters(
+            hci.HCI_ErrorCode.SUCCESS
+        )
 
         try:
             offset = 0
-            for field in cls.return_parameters_fields:
+            for field in cls.return_parameters_class.fields:
                 field_name, field_type = field
                 field_value, field_size = hci.HCI_Object.parse_field(
                     parameters, offset, field_type
@@ -94,9 +103,30 @@ class HCI_LE_Get_Vendor_Capabilities_Command(hci.HCI_Command):
 
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
+# APCF Subcommands
+class LeApcfOpcode(hci.SpecableEnum):
+    ENABLE = 0x00
+    SET_FILTERING_PARAMETERS = 0x01
+    BROADCASTER_ADDRESS = 0x02
+    SERVICE_UUID = 0x03
+    SERVICE_SOLICITATION_UUID = 0x04
+    LOCAL_NAME = 0x05
+    MANUFACTURER_DATA = 0x06
+    SERVICE_DATA = 0x07
+    TRANSPORT_DISCOVERY_SERVICE = 0x08
+    AD_TYPE_FILTER = 0x09
+    READ_EXTENDED_FEATURES = 0xFF
+
+
 @dataclasses.dataclass
-class HCI_LE_APCF_Command(hci.HCI_Command):
+class HCI_LE_APCF_ReturnParameters(hci.HCI_StatusReturnParameters):
+    opcode: int = field(metadata=LeApcfOpcode.type_metadata(1))
+    payload: bytes = field(metadata=hci.metadata('*'))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_LE_APCF_ReturnParameters)
+@dataclasses.dataclass
+class HCI_LE_APCF_Command(hci.HCI_SyncCommand[HCI_LE_APCF_ReturnParameters]):
     # pylint: disable=line-too-long
     '''
     See https://source.android.com/docs/core/connect/bluetooth/hci_requirements#le_apcf_command
@@ -105,52 +135,52 @@ class HCI_LE_APCF_Command(hci.HCI_Command):
     implementation. A future enhancement may define subcommand-specific data structures.
     '''
 
-    # APCF Subcommands
-    class Opcode(hci.SpecableEnum):
-        ENABLE = 0x00
-        SET_FILTERING_PARAMETERS = 0x01
-        BROADCASTER_ADDRESS = 0x02
-        SERVICE_UUID = 0x03
-        SERVICE_SOLICITATION_UUID = 0x04
-        LOCAL_NAME = 0x05
-        MANUFACTURER_DATA = 0x06
-        SERVICE_DATA = 0x07
-        TRANSPORT_DISCOVERY_SERVICE = 0x08
-        AD_TYPE_FILTER = 0x09
-        READ_EXTENDED_FEATURES = 0xFF
-
-    opcode: int = dataclasses.field(metadata=Opcode.type_metadata(1))
+    opcode: int = dataclasses.field(metadata=LeApcfOpcode.type_metadata(1))
     payload: bytes = dataclasses.field(metadata=hci.metadata("*"))
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('opcode', Opcode.type_spec(1)),
-        ('payload', '*'),
-    ]
-
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_Get_Controller_Activity_Energy_Info_Command(hci.HCI_Command):
+class HCI_Get_Controller_Activity_Energy_Info_ReturnParameters(
+    hci.HCI_StatusReturnParameters
+):
+    total_tx_time_ms: int = field(metadata=hci.metadata(4))
+    total_rx_time_ms: int = field(metadata=hci.metadata(4))
+    total_idle_time_ms: int = field(metadata=hci.metadata(4))
+    total_energy_used: int = field(metadata=hci.metadata(4))
+
+
+@hci.HCI_SyncCommand.sync_command(
+    HCI_Get_Controller_Activity_Energy_Info_ReturnParameters
+)
+@dataclasses.dataclass
+class HCI_Get_Controller_Activity_Energy_Info_Command(
+    hci.HCI_SyncCommand[HCI_Get_Controller_Activity_Energy_Info_ReturnParameters]
+):
     # pylint: disable=line-too-long
     '''
     See https://source.android.com/docs/core/connect/bluetooth/hci_requirements#le_get_controller_activity_energy_info
     '''
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('total_tx_time_ms', 4),
-        ('total_rx_time_ms', 4),
-        ('total_idle_time_ms', 4),
-        ('total_energy_used', 4),
-    ]
-
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
+# A2DP Hardware Offload Subcommands
+class A2dpHardwareOffloadOpcode(hci.SpecableEnum):
+    START_A2DP_OFFLOAD = 0x01
+    STOP_A2DP_OFFLOAD = 0x02
+
+
 @dataclasses.dataclass
-class HCI_A2DP_Hardware_Offload_Command(hci.HCI_Command):
+class HCI_A2DP_Hardware_Offload_ReturnParameters(hci.HCI_StatusReturnParameters):
+    opcode: int = dataclasses.field(metadata=A2dpHardwareOffloadOpcode.type_metadata(1))
+    payload: bytes = dataclasses.field(metadata=hci.metadata("*"))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_A2DP_Hardware_Offload_ReturnParameters)
+@dataclasses.dataclass
+class HCI_A2DP_Hardware_Offload_Command(
+    hci.HCI_SyncCommand[HCI_A2DP_Hardware_Offload_ReturnParameters]
+):
     # pylint: disable=line-too-long
     '''
     See https://source.android.com/docs/core/connect/bluetooth/hci_requirements#a2dp-hardware-offload-support
@@ -159,25 +189,27 @@ class HCI_A2DP_Hardware_Offload_Command(hci.HCI_Command):
     implementation. A future enhancement may define subcommand-specific data structures.
     '''
 
-    # A2DP Hardware Offload Subcommands
-    class Opcode(hci.SpecableEnum):
-        START_A2DP_OFFLOAD = 0x01
-        STOP_A2DP_OFFLOAD = 0x02
-
-    opcode: int = dataclasses.field(metadata=Opcode.type_metadata(1))
+    opcode: int = dataclasses.field(metadata=A2dpHardwareOffloadOpcode.type_metadata(1))
     payload: bytes = dataclasses.field(metadata=hci.metadata("*"))
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('opcode', Opcode.type_spec(1)),
-        ('payload', '*'),
-    ]
-
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
+# Dynamic Audio Buffer Subcommands
+class DynamicAudioBufferOpcode(hci.SpecableEnum):
+    GET_AUDIO_BUFFER_TIME_CAPABILITY = 0x01
+
+
 @dataclasses.dataclass
-class HCI_Dynamic_Audio_Buffer_Command(hci.HCI_Command):
+class HCI_Dynamic_Audio_Buffer_ReturnParameters(hci.HCI_StatusReturnParameters):
+    opcode: int = dataclasses.field(metadata=DynamicAudioBufferOpcode.type_metadata(1))
+    payload: bytes = dataclasses.field(metadata=hci.metadata("*"))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_Dynamic_Audio_Buffer_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Dynamic_Audio_Buffer_Command(
+    hci.HCI_SyncCommand[HCI_Dynamic_Audio_Buffer_ReturnParameters]
+):
     # pylint: disable=line-too-long
     '''
     See https://source.android.com/docs/core/connect/bluetooth/hci_requirements#dynamic-audio-buffer-command
@@ -186,19 +218,9 @@ class HCI_Dynamic_Audio_Buffer_Command(hci.HCI_Command):
     implementation. A future enhancement may define subcommand-specific data structures.
     '''
 
-    # Dynamic Audio Buffer Subcommands
-    class Opcode(hci.SpecableEnum):
-        GET_AUDIO_BUFFER_TIME_CAPABILITY = 0x01
-
-    opcode: int = dataclasses.field(metadata=Opcode.type_metadata(1))
+    opcode: int = dataclasses.field(metadata=DynamicAudioBufferOpcode.type_metadata(1))
     payload: bytes = dataclasses.field(metadata=hci.metadata("*"))
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('opcode', Opcode.type_spec(1)),
-        ('payload', '*'),
-    ]
-
 
 # -----------------------------------------------------------------------------
 class HCI_Android_Vendor_Event(hci.HCI_Extended_Event):

bumble/vendor/zephyr/hci.py

@@ -46,9 +46,19 @@ class TX_Power_Level_Command:
 
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_Write_Tx_Power_Level_Command(hci.HCI_Command, TX_Power_Level_Command):
+class HCI_Write_Tx_Power_Level_ReturnParameters(hci.HCI_StatusReturnParameters):
+    handle_type: int = hci.field(metadata=hci.metadata(1))
+    connection_handle: int = hci.field(metadata=hci.metadata(2))
+    selected_tx_power_level: int = hci.field(metadata=hci.metadata(-1))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_Write_Tx_Power_Level_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Write_Tx_Power_Level_Command(
+    hci.HCI_SyncCommand[HCI_Write_Tx_Power_Level_ReturnParameters],
+    TX_Power_Level_Command,
+):
     '''
     Write TX power level. See BT_HCI_OP_VS_WRITE_TX_POWER_LEVEL in
     https://github.com/zephyrproject-rtos/zephyr/blob/main/include/zephyr/bluetooth/hci_vs.h
@@ -61,18 +71,21 @@ class HCI_Write_Tx_Power_Level_Command(hci.HCI_Command, TX_Power_Level_Command):
     connection_handle: int = dataclasses.field(metadata=hci.metadata(2))
     tx_power_level: int = dataclasses.field(metadata=hci.metadata(-1))
 
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('handle_type', 1),
-        ('connection_handle', 2),
-        ('selected_tx_power_level', -1),
-    ]
-
 
 # -----------------------------------------------------------------------------
-@hci.HCI_Command.command
 @dataclasses.dataclass
-class HCI_Read_Tx_Power_Level_Command(hci.HCI_Command, TX_Power_Level_Command):
+class HCI_Read_Tx_Power_Level_ReturnParameters(hci.HCI_StatusReturnParameters):
+    handle_type: int = hci.field(metadata=hci.metadata(1))
+    connection_handle: int = hci.field(metadata=hci.metadata(2))
+    tx_power_level: int = hci.field(metadata=hci.metadata(-1))
+
+
+@hci.HCI_SyncCommand.sync_command(HCI_Read_Tx_Power_Level_ReturnParameters)
+@dataclasses.dataclass
+class HCI_Read_Tx_Power_Level_Command(
+    hci.HCI_SyncCommand[HCI_Read_Tx_Power_Level_ReturnParameters],
+    TX_Power_Level_Command,
+):
     '''
     Read TX power level. See BT_HCI_OP_VS_READ_TX_POWER_LEVEL in
     https://github.com/zephyrproject-rtos/zephyr/blob/main/include/zephyr/bluetooth/hci_vs.h
@@ -83,10 +96,3 @@ class HCI_Read_Tx_Power_Level_Command(hci.HCI_Command, TX_Power_Level_Command):
 
     handle_type: int = dataclasses.field(metadata=hci.metadata(1))
     connection_handle: int = dataclasses.field(metadata=hci.metadata(2))
-
-    return_parameters_fields = [
-        ('status', hci.STATUS_SPEC),
-        ('handle_type', 1),
-        ('connection_handle', 2),
-        ('tx_power_level', -1),
-    ]

docs/mkdocs/src/platforms/linux.md

@@ -63,7 +63,7 @@ HCI sockets provide a way to send/receive HCI packets to/from a Bluetooth contro
 See the [HCI Socket Transport page](../transports/hci_socket.md) for details on the `hci-socket` tansport syntax.
 
 The HCI device referenced by an `hci-socket` transport (`hci<X>`, where `<X>` is an integer, with `hci0` being the first controller device, and so on) must be in the `DOWN` state before it can be opened as a transport.
-You can bring a HCI controller `UP` or `DOWN` with `hciconfig hci<X> up` and `hciconfig hci<X> up`.
+You can bring a HCI controller `UP` or `DOWN` with `hciconfig hci<X> up` and `hciconfig hci<X> down`.
 
 !!! tip "HCI Socket Permissions"
     By default, when running as a regular user, you won't have the permission to use

docs/mkdocs/src/platforms/zephyr.md

@@ -37,15 +37,16 @@ The vendor specific HCI commands to read and write TX power are defined in
 from bumble.vendor.zephyr.hci import HCI_Write_Tx_Power_Level_Command
 
 # set advertising power to -4 dB
-response = await host.send_command(
+response = await host.send_sync_command(
     HCI_Write_Tx_Power_Level_Command(
         handle_type=HCI_Write_Tx_Power_Level_Command.TX_POWER_HANDLE_TYPE_ADV,
         connection_handle=0,
         tx_power_level=-4,
-    )
+    ),
+    check_status=False
 )
 
-if response.return_parameters.status == HCI_SUCCESS:
-    print(f"TX power set to {response.return_parameters.selected_tx_power_level}")
+if response.status == HCI_SUCCESS:
+    print(f"TX power set to {response.selected_tx_power_level}")
 
 ```

examples/heart_rate_server.py

@@ -71,8 +71,8 @@ async def main() -> None:
                 rr_intervals=random.choice(
                     (
                         (
-                            random.randint(900, 1100) / 1000,
-                            random.randint(900, 1100) / 1000,
+                            random.randint(900, 1100) // 1000,
+                            random.randint(900, 1100) // 1000,
                         ),
                         None,
                     )

examples/run_gatt_client.py

@@ -19,10 +19,10 @@ import asyncio
 import sys
 
 import bumble.logging
+from bumble import gatt_client
 from bumble.colors import color
 from bumble.core import ProtocolError
-from bumble.device import Device, Peer
-from bumble.gatt import show_services
+from bumble.device import Connection, Device
 from bumble.transport import open_transport
 from bumble.utils import AsyncRunner
 
@@ -34,24 +34,27 @@ class Listener(Device.Listener):
 
     @AsyncRunner.run_in_task()
     # pylint: disable=invalid-overridden-method
-    async def on_connection(self, connection):
+    async def on_connection(self, connection: Connection):
         print(f'=== Connected to {connection}')
 
         # Discover all services
         print('=== Discovering services')
-        peer = Peer(connection)
-        await peer.discover_services()
-        for service in peer.services:
+        if connection.device.config.eatt_enabled:
+            client = await gatt_client.Client.connect_eatt(connection)
+        else:
+            client = connection.gatt_client
+        await client.discover_services()
+        for service in client.services:
             await service.discover_characteristics()
             for characteristic in service.characteristics:
                 await characteristic.discover_descriptors()
 
         print('=== Services discovered')
-        show_services(peer.services)
+        gatt_client.show_services(client.services)
 
         # Discover all attributes
         print('=== Discovering attributes')
-        attributes = await peer.discover_attributes()
+        attributes = await client.discover_attributes()
         for attribute in attributes:
             print(attribute)
         print('=== Attributes discovered')
@@ -59,7 +62,7 @@ class Listener(Device.Listener):
         # Read all attributes
         for attribute in attributes:
             try:
-                value = await peer.read_value(attribute)
+                value = await client.read_value(attribute)
                 print(color(f'0x{attribute.handle:04X} = {value.hex()}', 'green'))
             except ProtocolError as error:
                 print(color(f'cannot read {attribute.handle:04X}:', 'red'), error)

rust/pytests/wrapper/drivers.rs

@@ -17,6 +17,6 @@ use pyo3::PyResult;
 
 #[pyo3_asyncio::tokio::test]
 async fn realtek_driver_info_all_drivers() -> PyResult<()> {
-    assert_eq!(12, DriverInfo::all_drivers()?.len());
+    assert_eq!(13, DriverInfo::all_drivers()?.len());
     Ok(())
 }

tests/battery_service_test.py

@@ -0,0 +1,34 @@
+# Copyright 2021-2026 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 pytest
+
+from bumble import device as device_module
+from bumble.profiles import battery_service
+
+from . import test_utils
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_read_battery_level():
+    devices = await test_utils.TwoDevices.create_with_connection()
+    service = battery_service.BatteryService(lambda _: 1)
+    devices[0].add_service(service)
+
+    async with device_module.Peer(devices.connections[1]) as peer:
+        client = peer.create_service_proxy(battery_service.BatteryServiceProxy)
+        assert client
+        assert await client.battery_level.read_value() == 1

tests/device_test.py

@@ -42,7 +42,6 @@ from bumble.hci import (
     HCI_CREATE_CONNECTION_COMMAND,
     HCI_SUCCESS,
     Address,
-    HCI_Command_Complete_Event,
     HCI_Command_Status_Event,
     HCI_Connection_Complete_Event,
     HCI_Connection_Request_Event,
@@ -154,10 +153,10 @@ async def test_device_connect_parallel():
         assert packet.name == 'HCI_ACCEPT_CONNECTION_REQUEST_COMMAND'
 
         d1.host.on_hci_packet(
-            HCI_Command_Complete_Event(
+            HCI_Command_Status_Event(
+                status=HCI_COMMAND_STATUS_PENDING,
                 num_hci_command_packets=1,
                 command_opcode=HCI_ACCEPT_CONNECTION_REQUEST_COMMAND,
-                return_parameters=b"\x00",
             )
         )
 
@@ -188,10 +187,10 @@ async def test_device_connect_parallel():
         assert packet.name == 'HCI_ACCEPT_CONNECTION_REQUEST_COMMAND'
 
         d2.host.on_hci_packet(
-            HCI_Command_Complete_Event(
+            HCI_Command_Status_Event(
+                status=HCI_COMMAND_STATUS_PENDING,
                 num_hci_command_packets=1,
                 command_opcode=HCI_ACCEPT_CONNECTION_REQUEST_COMMAND,
-                return_parameters=b"\x00",
             )
         )
 
@@ -292,9 +291,9 @@ async def test_legacy_advertising_disconnection(auto_restart):
     await devices[0].start_advertising(
         auto_restart=auto_restart, advertising_interval_min=1.0
     )
-    connecion = await devices[1].connect(devices[0].random_address)
+    connection = await devices[1].connect(devices[0].random_address)
 
-    await connecion.disconnect()
+    await connection.disconnect()
 
     await async_barrier()
     await async_barrier()

tests/gatt_test.py

@@ -28,6 +28,7 @@ from unittest.mock import ANY, AsyncMock, Mock
 import pytest
 from typing_extensions import Self
 
+from bumble import gatt_client, l2cap
 from bumble.att import (
     ATT_ATTRIBUTE_NOT_FOUND_ERROR,
     ATT_PDU,
@@ -63,7 +64,6 @@ from bumble.gatt_adapters import (
     UTF8CharacteristicAdapter,
     UTF8CharacteristicProxyAdapter,
 )
-from bumble.gatt_client import CharacteristicProxy
 
 from .test_utils import Devices, TwoDevices, async_barrier
 
@@ -140,7 +140,7 @@ async def test_characteristic_encoding():
     await c.write_value(Mock(), bytes([122]))
     assert c.value == 122
 
-    class FooProxy(CharacteristicProxy):
+    class FooProxy(gatt_client.CharacteristicProxy):
         def __init__(self, characteristic):
             super().__init__(
                 characteristic.client,
@@ -456,7 +456,7 @@ async def test_CharacteristicProxyAdapter() -> None:
         async def write_value(self, handle, value, with_response=False):
             self.value = value
 
-    class TestAttributeProxy(CharacteristicProxy):
+    class TestAttributeProxy(gatt_client.CharacteristicProxy):
         def __init__(self, value) -> None:
             super().__init__(Client(value), 0, 0, None, 0)  # type: ignore
 
@@ -1425,10 +1425,10 @@ async def test_get_characteristics_by_uuid():
     await peer.discover_characteristics()
     c = peer.get_characteristics_by_uuid(uuid=UUID('1234'))
     assert len(c) == 2
-    assert isinstance(c[0], CharacteristicProxy)
+    assert isinstance(c[0], gatt_client.CharacteristicProxy)
     c = peer.get_characteristics_by_uuid(uuid=UUID('1234'), service=UUID('ABCD'))
     assert len(c) == 1
-    assert isinstance(c[0], CharacteristicProxy)
+    assert isinstance(c[0], gatt_client.CharacteristicProxy)
     c = peer.get_characteristics_by_uuid(uuid=UUID('1234'), service=UUID('AAAA'))
     assert len(c) == 0
 
@@ -1463,6 +1463,181 @@ async def test_write_return_error():
         assert e.value.error_code == ErrorCode.VALUE_NOT_ALLOWED
 
 
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_eatt_read():
+    devices = await TwoDevices.create_with_connection()
+    devices[1].gatt_server.register_eatt()
+
+    characteristic = Characteristic(
+        '1234',
+        Characteristic.Properties.READ,
+        Characteristic.Permissions.READABLE,
+        b'9999',
+    )
+    service = Service('ABCD', [characteristic])
+    devices[1].add_service(service)
+
+    client = await gatt_client.Client.connect_eatt(devices.connections[0])
+    await client.discover_services()
+    service_proxy = client.get_services_by_uuid(service.uuid)[0]
+    await service_proxy.discover_characteristics()
+    characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+        characteristic.uuid
+    )[0]
+    assert await characteristic_proxy.read_value() == b'9999'
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_eatt_write():
+    devices = await TwoDevices.create_with_connection()
+    devices[1].gatt_server.register_eatt()
+
+    write_queue = asyncio.Queue()
+    characteristic = Characteristic(
+        '1234',
+        Characteristic.Properties.WRITE,
+        Characteristic.Permissions.WRITEABLE,
+        CharacteristicValue(write=lambda *args: write_queue.put_nowait(args)),
+    )
+    service = Service('ABCD', [characteristic])
+    devices[1].add_service(service)
+
+    client = await gatt_client.Client.connect_eatt(devices.connections[0])
+    await client.discover_services()
+    service_proxy = client.get_services_by_uuid(service.uuid)[0]
+    await service_proxy.discover_characteristics()
+    characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+        characteristic.uuid
+    )[0]
+    await characteristic_proxy.write_value(b'9999')
+    assert await write_queue.get() == (devices.connections[1], b'9999')
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_eatt_notify():
+    devices = await TwoDevices.create_with_connection()
+    devices[1].gatt_server.register_eatt()
+
+    characteristic = Characteristic(
+        '1234',
+        Characteristic.Properties.NOTIFY,
+        Characteristic.Permissions.WRITEABLE,
+    )
+    service = Service('ABCD', [characteristic])
+    devices[1].add_service(service)
+
+    clients = [
+        (
+            devices.connections[0].gatt_client,
+            asyncio.Queue[bytes](),
+        ),
+        (
+            await gatt_client.Client.connect_eatt(devices.connections[0]),
+            asyncio.Queue[bytes](),
+        ),
+        (
+            await gatt_client.Client.connect_eatt(devices.connections[0]),
+            asyncio.Queue[bytes](),
+        ),
+    ]
+    for client, queue in clients:
+        await client.discover_services()
+        service_proxy = client.get_services_by_uuid(service.uuid)[0]
+        await service_proxy.discover_characteristics()
+        characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+            characteristic.uuid
+        )[0]
+
+    for client, queue in clients[:2]:
+        characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+            characteristic.uuid
+        )[0]
+        await characteristic_proxy.subscribe(queue.put_nowait, prefer_notify=True)
+
+    await devices[1].gatt_server.notify_subscribers(characteristic, b'1234')
+    for _, queue in clients[:2]:
+        assert await queue.get() == b'1234'
+        assert queue.empty()
+    assert clients[2][1].empty()
+
+    await devices[1].gatt_server.notify_subscriber(
+        devices.connections[1], characteristic, b'5678'
+    )
+    for _, queue in clients[:2]:
+        assert await queue.get() == b'5678'
+        assert queue.empty()
+    assert clients[2][1].empty()
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_eatt_indicate():
+    devices = await TwoDevices.create_with_connection()
+    devices[1].gatt_server.register_eatt()
+
+    characteristic = Characteristic(
+        '1234',
+        Characteristic.Properties.INDICATE,
+        Characteristic.Permissions.WRITEABLE,
+    )
+    service = Service('ABCD', [characteristic])
+    devices[1].add_service(service)
+
+    clients = [
+        (
+            devices.connections[0].gatt_client,
+            asyncio.Queue[bytes](),
+        ),
+        (
+            await gatt_client.Client.connect_eatt(devices.connections[0]),
+            asyncio.Queue[bytes](),
+        ),
+        (
+            await gatt_client.Client.connect_eatt(devices.connections[0]),
+            asyncio.Queue[bytes](),
+        ),
+    ]
+    for client, queue in clients:
+        await client.discover_services()
+        service_proxy = client.get_services_by_uuid(service.uuid)[0]
+        await service_proxy.discover_characteristics()
+        characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+            characteristic.uuid
+        )[0]
+
+    for client, queue in clients[:2]:
+        characteristic_proxy = service_proxy.get_characteristics_by_uuid(
+            characteristic.uuid
+        )[0]
+        await characteristic_proxy.subscribe(queue.put_nowait, prefer_notify=False)
+
+    await devices[1].gatt_server.indicate_subscribers(characteristic, b'1234')
+    for _, queue in clients[:2]:
+        assert await queue.get() == b'1234'
+        assert queue.empty()
+    assert clients[2][1].empty()
+
+    await devices[1].gatt_server.indicate_subscriber(
+        devices.connections[1], characteristic, b'5678'
+    )
+    for _, queue in clients[:2]:
+        assert await queue.get() == b'5678'
+        assert queue.empty()
+    assert clients[2][1].empty()
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_eatt_connection_failure():
+    devices = await TwoDevices.create_with_connection()
+
+    with pytest.raises(l2cap.L2capError):
+        await gatt_client.Client.connect_eatt(devices.connections[0])
+
+
 # -----------------------------------------------------------------------------
 if __name__ == '__main__':
     logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())

tests/hci_test.py

@@ -20,7 +20,7 @@ import struct
 
 import pytest
 
-from bumble import hci
+from bumble import hci, utils
 
 # -----------------------------------------------------------------------------
 # pylint: disable=invalid-name
@@ -136,43 +136,25 @@ def test_HCI_LE_Channel_Selection_Algorithm_Event():
 # -----------------------------------------------------------------------------
 def test_HCI_Command_Complete_Event():
     # With a serializable object
-    event = hci.HCI_Command_Complete_Event(
+    event1 = hci.HCI_Command_Complete_Event(
         num_hci_command_packets=34,
         command_opcode=hci.HCI_LE_READ_BUFFER_SIZE_COMMAND,
-        return_parameters=hci.HCI_LE_Read_Buffer_Size_Command.create_return_parameters(
+        return_parameters=hci.HCI_LE_Read_Buffer_Size_Command.return_parameters_class(
             status=0,
             le_acl_data_packet_length=1234,
             total_num_le_acl_data_packets=56,
         ),
     )
-    basic_check(event)
-
-    # With an arbitrary byte array
-    event = hci.HCI_Command_Complete_Event(
-        num_hci_command_packets=1,
-        command_opcode=hci.HCI_RESET_COMMAND,
-        return_parameters=bytes([1, 2, 3, 4]),
-    )
-    basic_check(event)
-
-    # With a simple status as a 1-byte array
-    event = hci.HCI_Command_Complete_Event(
-        num_hci_command_packets=1,
-        command_opcode=hci.HCI_RESET_COMMAND,
-        return_parameters=bytes([7]),
-    )
-    basic_check(event)
-    event = hci.HCI_Packet.from_bytes(bytes(event))
-    assert event.return_parameters == 7
+    basic_check(event1)
 
     # With a simple status as an integer status
-    event = hci.HCI_Command_Complete_Event(
+    event3 = hci.HCI_Command_Complete_Event(
         num_hci_command_packets=1,
         command_opcode=hci.HCI_RESET_COMMAND,
-        return_parameters=9,
+        return_parameters=hci.HCI_StatusReturnParameters(hci.HCI_ErrorCode(9)),
     )
-    basic_check(event)
-    assert event.return_parameters == 9
+    basic_check(event3)
+    assert event3.return_parameters.status == 9
 
 
 # -----------------------------------------------------------------------------
@@ -229,6 +211,28 @@ def test_HCI_Vendor_Event():
     assert isinstance(parsed, hci.HCI_Vendor_Event)
 
 
+# -----------------------------------------------------------------------------
+def test_return_parameters() -> None:
+    params = hci.HCI_Reset_Command.parse_return_parameters(bytes.fromhex('3C'))
+    assert params.status == hci.HCI_ErrorCode.ADVERTISING_TIMEOUT_ERROR
+    assert isinstance(params.status, utils.OpenIntEnum)
+
+    params = hci.HCI_Read_BD_ADDR_Command.parse_return_parameters(
+        bytes.fromhex('3C001122334455')
+    )
+    assert params.status == hci.HCI_ErrorCode.ADVERTISING_TIMEOUT_ERROR
+    assert isinstance(params.status, utils.OpenIntEnum)
+    assert isinstance(params.bd_addr, hci.Address)
+
+    params = hci.HCI_Read_Local_Name_Command.parse_return_parameters(
+        bytes.fromhex('0068656c6c6f') + bytes(248 - 5)
+    )
+    assert params.status == hci.HCI_ErrorCode.SUCCESS
+    assert isinstance(params.local_name, bytes)
+    assert len(params.local_name) == 248
+    assert hci.map_null_terminated_utf8_string(params.local_name) == 'hello'
+
+
 # -----------------------------------------------------------------------------
 def test_HCI_Command():
     command = hci.HCI_Command(op_code=0x5566)
@@ -291,7 +295,7 @@ def test_custom_le_meta_event():
         for clazz in inspect.getmembers(hci)
         if isinstance(clazz[1], type)
         and issubclass(clazz[1], hci.HCI_Command)
-        and clazz[1] is not hci.HCI_Command
+        and clazz[1] not in (hci.HCI_Command, hci.HCI_SyncCommand, hci.HCI_AsyncCommand)
     ],
 )
 def test_hci_command_subclasses_op_code(clazz: type[hci.HCI_Command]):
@@ -620,21 +624,19 @@ def test_HCI_Read_Local_Supported_Codecs_Command_Complete():
 
 # -----------------------------------------------------------------------------
 def test_HCI_Read_Local_Supported_Codecs_V2_Command_Complete():
-    returned_parameters = (
-        hci.HCI_Read_Local_Supported_Codecs_V2_Command.parse_return_parameters(
-            bytes(
-                [
-                    hci.HCI_SUCCESS,
-                    3,
-                    hci.CodecID.A_LOG,
-                    hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.BR_EDR_ACL,
-                    hci.CodecID.CVSD,
-                    hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.BR_EDR_SCO,
-                    hci.CodecID.LINEAR_PCM,
-                    hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.LE_CIS,
-                    0,
-                ]
-            )
+    returned_parameters = hci.HCI_Read_Local_Supported_Codecs_V2_Command.parse_return_parameters(
+        bytes(
+            [
+                hci.HCI_SUCCESS,
+                3,
+                hci.CodecID.A_LOG,
+                hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.BR_EDR_ACL,
+                hci.CodecID.CVSD,
+                hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.BR_EDR_SCO,
+                hci.CodecID.LINEAR_PCM,
+                hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.LE_CIS,
+                0,
+            ]
         )
     )
     assert returned_parameters.standard_codec_ids == [
@@ -643,9 +645,9 @@ def test_HCI_Read_Local_Supported_Codecs_V2_Command_Complete():
         hci.CodecID.LINEAR_PCM,
     ]
     assert returned_parameters.standard_codec_transports == [
-        hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.BR_EDR_ACL,
-        hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.BR_EDR_SCO,
-        hci.HCI_Read_Local_Supported_Codecs_V2_Command.Transport.LE_CIS,
+        hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.BR_EDR_ACL,
+        hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.BR_EDR_SCO,
+        hci.HCI_Read_Local_Supported_Codecs_V2_ReturnParameters.Transport.LE_CIS,
     ]
 
 
@@ -737,6 +739,7 @@ def run_test_commands():
 if __name__ == '__main__':
     run_test_events()
     run_test_commands()
+    test_return_parameters()
     test_address()
     test_custom()
     test_iso_data_packet()

tests/heart_rate_service_test.py

@@ -0,0 +1,89 @@
+# Copyright 2021-2026 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 asyncio
+import itertools
+from collections.abc import Sequence
+
+import pytest
+
+from bumble import device as device_module
+from bumble.profiles import heart_rate_service
+
+from . import test_utils
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "heart_rate, sensor_contact_detected, energy_expanded, rr_intervals",
+    itertools.product(
+        (1, 1000), (True, False, None), (2, None), ((3.0, 4.0, 5.0), None)
+    ),
+)
+async def test_read_measurement(
+    heart_rate: int,
+    sensor_contact_detected: bool | None,
+    energy_expanded: int | None,
+    rr_intervals: Sequence[int] | None,
+):
+    devices = await test_utils.TwoDevices.create_with_connection()
+    measurement = heart_rate_service.HeartRateService.HeartRateMeasurement(
+        heart_rate, sensor_contact_detected, energy_expanded, rr_intervals
+    )
+    service = heart_rate_service.HeartRateService(lambda _: measurement)
+    devices[0].add_service(service)
+
+    async with device_module.Peer(devices.connections[1]) as peer:
+        client = peer.create_service_proxy(heart_rate_service.HeartRateServiceProxy)
+        assert client
+        assert await client.heart_rate_measurement.read_value() == measurement
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_read_body_sensor_location():
+    devices = await test_utils.TwoDevices.create_with_connection()
+    measurement = heart_rate_service.HeartRateService.HeartRateMeasurement(0)
+    location = heart_rate_service.HeartRateService.BodySensorLocation.FINGER
+    service = heart_rate_service.HeartRateService(
+        lambda _: measurement,
+        body_sensor_location=location,
+    )
+    devices[0].add_service(service)
+
+    async with device_module.Peer(devices.connections[1]) as peer:
+        client = peer.create_service_proxy(heart_rate_service.HeartRateServiceProxy)
+        assert client
+        assert client.body_sensor_location
+        assert await client.body_sensor_location.read_value() == location
+
+
+# -----------------------------------------------------------------------------
+@pytest.mark.asyncio
+async def test_reset_energy_expended() -> None:
+    devices = await test_utils.TwoDevices.create_with_connection()
+    measurement = heart_rate_service.HeartRateService.HeartRateMeasurement(1)
+    reset_energy_expended = asyncio.Queue[None]()
+    service = heart_rate_service.HeartRateService(
+        lambda _: measurement,
+        reset_energy_expended=lambda _: reset_energy_expended.put_nowait(None),
+    )
+    devices[0].add_service(service)
+
+    async with device_module.Peer(devices.connections[1]) as peer:
+        client = peer.create_service_proxy(heart_rate_service.HeartRateServiceProxy)
+        assert client
+        await client.reset_energy_expended()
+        await reset_energy_expended.get()

tests/host_test.py

@@ -15,6 +15,7 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+import asyncio
 import logging
 import unittest
 import unittest.mock
@@ -22,9 +23,17 @@ import unittest.mock
 import pytest
 
 from bumble.controller import Controller
-from bumble.hci import HCI_AclDataPacket
+from bumble.hci import (
+    HCI_AclDataPacket,
+    HCI_Command_Complete_Event,
+    HCI_Error,
+    HCI_ErrorCode,
+    HCI_Event,
+    HCI_Reset_Command,
+    HCI_StatusReturnParameters,
+)
 from bumble.host import DataPacketQueue, Host
-from bumble.transport.common import AsyncPipeSink
+from bumble.transport.common import AsyncPipeSink, TransportSink
 
 # -----------------------------------------------------------------------------
 # Logging
@@ -151,3 +160,58 @@ def test_data_packet_queue():
     assert drain_listener.on_flow.call_count == 1
     assert queue.queued == 15
     assert queue.completed == 15
+
+
+# -----------------------------------------------------------------------------
+class Source:
+    terminated: asyncio.Future[None]
+    sink: TransportSink
+
+    def set_packet_sink(self, sink: TransportSink) -> None:
+        self.sink = sink
+
+
+class Sink:
+    response: HCI_Event
+
+    def __init__(self, source: Source, response: HCI_Event) -> None:
+        self.source = source
+        self.response = response
+
+    def on_packet(self, packet: bytes) -> None:
+        self.source.sink.on_packet(bytes(self.response))
+
+
+@pytest.mark.asyncio
+async def test_send_sync_command() -> None:
+    source = Source()
+    sink = Sink(
+        source,
+        HCI_Command_Complete_Event(
+            1,
+            HCI_Reset_Command.op_code,
+            HCI_StatusReturnParameters(status=HCI_ErrorCode.SUCCESS),
+        ),
+    )
+
+    host = Host(source, sink)
+
+    # Sync command with success
+    response1 = await host.send_sync_command(HCI_Reset_Command())
+    assert response1.status == HCI_ErrorCode.SUCCESS
+
+    # Sync command with error status should raise
+    error_response = HCI_Command_Complete_Event(
+        1,
+        HCI_Reset_Command.op_code,
+        HCI_StatusReturnParameters(status=HCI_ErrorCode.COMMAND_DISALLOWED_ERROR),
+    )
+    sink.response = error_response
+    with pytest.raises(HCI_Error) as excinfo:
+        await host.send_sync_command(HCI_Reset_Command())
+
+    assert excinfo.value.error_code == error_response.return_parameters.status
+
+    # Sync command with error status should not raise when `check_status` is False
+    response2 = await host.send_sync_command(HCI_Reset_Command(), check_status=False)
+    assert response2.status == HCI_ErrorCode.COMMAND_DISALLOWED_ERROR

tests/l2cap_test.py

@@ -239,20 +239,7 @@ async def transfer_payload(
     channels[1].sink = received.put_nowait
     sdu_lengths = (21, 70, 700, 5523)
 
-    if isinstance(channels[1], l2cap.LeCreditBasedChannel):
-        mps = channels[1].mps
-    elif isinstance(
-        processor := channels[1].processor, l2cap.EnhancedRetransmissionProcessor
-    ):
-        mps = processor.mps
-    else:
-        mps = channels[1].mtu
-
-    messages = [
-        bytes([i % 8 for i in range(sdu_length)])
-        for sdu_length in sdu_lengths
-        if sdu_length <= mps
-    ]
+    messages = [bytes([i % 8 for i in range(sdu_length)]) for sdu_length in sdu_lengths]
     for message in messages:
         channels[0].write(message)
         if isinstance(channels[0], l2cap.LeCreditBasedChannel):
@@ -334,20 +321,26 @@ async def test_mtu():
 
 # -----------------------------------------------------------------------------
 @pytest.mark.asyncio
-async def test_enhanced_retransmission_mode():
+@pytest.mark.parametrize("mtu,", (50, 255, 256, 1000))
+async def test_enhanced_retransmission_mode(mtu: int):
     devices = TwoDevices()
     await devices.setup_connection()
 
     server_channels = asyncio.Queue[l2cap.ClassicChannel]()
     server = devices.devices[1].create_l2cap_server(
         spec=l2cap.ClassicChannelSpec(
-            mode=l2cap.TransmissionMode.ENHANCED_RETRANSMISSION
+            mode=l2cap.TransmissionMode.ENHANCED_RETRANSMISSION,
+            mtu=mtu,
+            mps=256,
         ),
         handler=server_channels.put_nowait,
     )
     client_channel = await devices.connections[0].create_l2cap_channel(
         spec=l2cap.ClassicChannelSpec(
-            server.psm, mode=l2cap.TransmissionMode.ENHANCED_RETRANSMISSION
+            server.psm,
+            mode=l2cap.TransmissionMode.ENHANCED_RETRANSMISSION,
+            mtu=mtu,
+            mps=1024,
         )
     )
     server_channel = await server_channels.get()

tests/self_test.py

@@ -57,15 +57,13 @@ async def test_self_disconnection():
     await two_devices.setup_connection()
     await two_devices.connections[0].disconnect()
     await async_barrier()
-    assert two_devices.connections[0] is None
-    assert two_devices.connections[1] is None
+    assert not two_devices.connections
 
     two_devices = TwoDevices()
     await two_devices.setup_connection()
     await two_devices.connections[1].disconnect()
     await async_barrier()
-    assert two_devices.connections[0] is None
-    assert two_devices.connections[1] is None
+    assert not two_devices.connections
 
 
 # -----------------------------------------------------------------------------

tests/test_utils.py

@@ -31,10 +31,10 @@ from bumble.transport.common import AsyncPipeSink
 
 # -----------------------------------------------------------------------------
 class Devices:
-    connections: list[Connection | None]
+    connections: dict[int, Connection]
 
     def __init__(self, num_devices: int) -> None:
-        self.connections = [None for _ in range(num_devices)]
+        self.connections = {}
 
         self.link = LocalLink()
         addresses = [":".join([f"F{i}"] * 6) for i in range(num_devices)]
@@ -60,12 +60,14 @@ class Devices:
             asyncio.get_event_loop().create_future() for _ in range(num_devices)
         ]
 
-    def on_connection(self, which, connection):
+    def on_connection(self, which: int, connection: Connection) -> None:
         self.connections[which] = connection
-        connection.on('disconnection', lambda code: self.on_disconnection(which))
+        connection.on(
+            connection.EVENT_DISCONNECTION, lambda *_: self.on_disconnection(which)
+        )
 
-    def on_disconnection(self, which):
-        self.connections[which] = None
+    def on_disconnection(self, which: int) -> None:
+        self.connections.pop(which, None)
 
     def on_paired(self, which: int, keys: PairingKeys) -> None:
         self.paired[which].set_result(keys)

web/heart_rate_monitor/heart_rate_monitor.py

@@ -89,7 +89,7 @@ class HeartRateMonitor:
 
     async def stop(self):
         # TODO: replace this once a proper reset is implemented in the lib.
-        await self.device.host.send_command(HCI_Reset_Command())
+        await self.device.host.send_sync_command(HCI_Reset_Command())
         await self.device.power_off()
         print('### Monitor stopped')
 

web/scanner/scanner.py

@@ -60,7 +60,7 @@ class Scanner(utils.EventEmitter):
 
     async def stop(self):
         # TODO: replace this once a proper reset is implemented in the lib.
-        await self.device.host.send_command(HCI_Reset_Command())
+        await self.device.host.send_sync_command(HCI_Reset_Command())
         await self.device.power_off()
         print('### Scanner stopped')
 

web/speaker/speaker.py

@@ -311,7 +311,7 @@ class Speaker:
 
     async def stop(self):
         # TODO: replace this once a proper reset is implemented in the lib.
-        await self.device.host.send_command(HCI_Reset_Command())
+        await self.device.host.send_sync_command(HCI_Reset_Command())
         await self.device.power_off()
         print('Speaker stopped')