Merge pull request #150 from zxzxwu/roleswitch

Support BR/EDR role switch & change events

bumble/device.py

@@ -101,6 +101,7 @@ from .hci import (
     HCI_Read_RSSI_Command,
     HCI_Reject_Connection_Request_Command,
     HCI_Remote_Name_Request_Command,
+    HCI_Switch_Role_Command,
     HCI_Set_Connection_Encryption_Command,
     HCI_StatusError,
     HCI_User_Confirmation_Request_Negative_Reply_Command,
@@ -621,7 +622,9 @@ class Connection(CompositeEventEmitter):
         assert self.transport == BT_BR_EDR_TRANSPORT
         self.handle = handle
         self.peer_resolvable_address = peer_resolvable_address
-        self.role = role
+        # Quirk: role might be known before complete
+        if self.role is None:
+            self.role = role
         self.parameters = parameters
 
     @property
@@ -669,6 +672,9 @@ class Connection(CompositeEventEmitter):
     async def encrypt(self, enable: bool = True) -> None:
         return await self.device.encrypt(self, enable)
 
+    async def switch_role(self, role: int) -> None:
+        return await self.device.switch_role(self, role)
+
     async def sustain(self, timeout=None):
         """Idles the current task waiting for a disconnect or timeout"""
 
@@ -2318,6 +2324,34 @@ class Device(CompositeEventEmitter):
                 'connection_encryption_failure', on_encryption_failure
             )
 
+    # [Classic only]
+    async def switch_role(self, connection: Connection, role: int):
+        pending_role_change = asyncio.get_running_loop().create_future()
+
+        def on_role_change(new_role):
+            pending_role_change.set_result(new_role)
+
+        def on_role_change_failure(error_code):
+            pending_role_change.set_exception(HCI_Error(error_code))
+
+        connection.on('role_change', on_role_change)
+        connection.on('role_change_failure', on_role_change_failure)
+
+        try:
+            result = await self.send_command(
+                HCI_Switch_Role_Command(bd_addr=connection.peer_address, role=role)  # type: ignore[call-arg]
+            )
+            if result.status != HCI_COMMAND_STATUS_PENDING:
+                logger.warning(
+                    'HCI_Switch_Role_Command failed: '
+                    f'{HCI_Constant.error_name(result.status)}'
+                )
+                raise HCI_StatusError(result)
+            await connection.abort_on('disconnection', pending_role_change)
+        finally:
+            connection.remove_listener('role_change', on_role_change)
+            connection.remove_listener('role_change_failure', on_role_change_failure)
+
     # [Classic only]
     async def request_remote_name(self, remote: Union[Address, Connection]) -> str:
         # Set up event handlers
@@ -2979,6 +3013,21 @@ class Device(CompositeEventEmitter):
         )
         connection.emit('connection_data_length_change')
 
+    # [Classic only]
+    @host_event_handler
+    @with_connection_from_address
+    def on_role_change(self, connection, new_role):
+        connection.role = new_role
+        connection.emit('role_change', new_role)
+
+    # [Classic only]
+    @host_event_handler
+    @try_with_connection_from_address
+    def on_role_change_failure(self, connection, address, error):
+        if connection:
+            connection.emit('role_change_failure', error)
+        self.emit('role_change_failure', address, error)
+
     @with_connection_from_handle
     def on_pairing_start(self, connection):
         connection.emit('pairing_start')

bumble/host.py

@@ -24,7 +24,10 @@ from bumble.colors import color
 from bumble.l2cap import L2CAP_PDU
 from bumble.snoop import Snooper
 
+from typing import Optional
+
 from .hci import (
+    Address,
     HCI_ACL_DATA_PACKET,
     HCI_COMMAND_COMPLETE_EVENT,
     HCI_COMMAND_PACKET,
@@ -141,6 +144,24 @@ class Host(AbortableEventEmitter):
         if controller_sink:
             self.set_packet_sink(controller_sink)
 
+    def find_connection_by_bd_addr(
+        self,
+        bd_addr: Address,
+        transport: Optional[int] = None,
+        check_address_type: bool = False,
+    ) -> Optional[Connection]:
+        for connection in self.connections.values():
+            if connection.peer_address.to_bytes() == bd_addr.to_bytes():
+                if (
+                    check_address_type
+                    and connection.peer_address.address_type != bd_addr.address_type
+                ):
+                    continue
+                if transport is None or connection.transport == transport:
+                    return connection
+
+        return None
+
     async def flush(self) -> None:
         # Make sure no command is pending
         await self.command_semaphore.acquire()
@@ -718,12 +739,17 @@ class Host(AbortableEventEmitter):
                 f'role change for {event.bd_addr}: '
                 f'{HCI_Constant.role_name(event.new_role)}'
             )
-            # TODO: lookup the connection and update the role
+            if connection := self.find_connection_by_bd_addr(
+                event.bd_addr, BT_BR_EDR_TRANSPORT
+            ):
+                connection.role = event.new_role
+            self.emit('role_change', event.bd_addr, event.new_role)
         else:
             logger.debug(
                 f'role change for {event.bd_addr} failed: '
                 f'{HCI_Constant.error_name(event.status)}'
             )
+            self.emit('role_change_failure', event.bd_addr, event.status)
 
     def on_hci_le_data_length_change_event(self, event):
         self.emit(