1# Copyright 2021-2022 Google LLC 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# https://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15# ----------------------------------------------------------------------------- 16# Imports 17# ----------------------------------------------------------------------------- 18import logging 19import grpc 20 21from .common import PumpedTransport, PumpedPacketSource, PumpedPacketSink 22from .emulated_bluetooth_pb2_grpc import EmulatedBluetoothServiceStub 23from .emulated_bluetooth_packets_pb2 import HCIPacket 24from .emulated_bluetooth_vhci_pb2_grpc import VhciForwardingServiceStub 25 26 27# ----------------------------------------------------------------------------- 28# Logging 29# ----------------------------------------------------------------------------- 30logger = logging.getLogger(__name__) 31 32 33# ----------------------------------------------------------------------------- 34async def open_android_emulator_transport(spec): 35 ''' 36 Open a transport connection to an Android emulator via its gRPC interface. 37 The parameter string has this syntax: 38 [<remote-host>:<remote-port>][,mode=<host|controller>] 39 The <remote-host>:<remote-port> part is optional, it defaults to localhost:8554 40 The mode=<mode> part is optional, it defaults to mode=host 41 When the mode is set to 'controller', the connection is for a controller (i.e the 42 Android Bluetooth stack will use the connected endpoint as its controller). When 43 the mode is set to 'host', the connection is to the 'Root Canal' virtual controller 44 that runs as part of the emulator, and used by the Android Bluetooth stack. 45 46 Examples: 47 (empty string) --> connect as a host to the emulator on localhost:8554 48 localhost:8555 --> connect as a host to the emulator on localhost:8555 49 mode=controller --> connect as a controller to the emulator on localhost:8554 50 ''' 51 52 # Wrapper for I/O operations 53 class HciDevice: 54 def __init__(self, hci_device): 55 self.hci_device = hci_device 56 57 async def read(self): 58 packet = await self.hci_device.read() 59 return bytes([packet.type]) + packet.packet 60 61 async def write(self, packet): 62 await self.hci_device.write( 63 HCIPacket( 64 type = packet[0], 65 packet = packet[1:] 66 ) 67 ) 68 69 # Parse the parameters 70 mode = 'host' 71 server_host = 'localhost' 72 server_port = 8554 73 if spec is not None: 74 params = spec.split(',') 75 for param in params: 76 if param.startswith('mode='): 77 mode = param.split('=')[1] 78 elif ':' in param: 79 server_host, server_port = param.split(':') 80 else: 81 raise ValueError('invalid parameter') 82 83 # Connect to the gRPC server 84 server_address = f'{server_host}:{server_port}' 85 logger.debug(f'connecting to gRPC server at {server_address}') 86 channel = grpc.aio.insecure_channel(server_address) 87 88 if mode == 'host': 89 # Connect as a host 90 service = EmulatedBluetoothServiceStub(channel) 91 hci_device = HciDevice(service.registerHCIDevice()) 92 elif mode == 'controller': 93 # Connect as a controller 94 service = VhciForwardingServiceStub(channel) 95 hci_device = HciDevice(service.attachVhci()) 96 else: 97 raise ValueError('invalid mode') 98 99 # Create the transport object 100 transport = PumpedTransport( 101 PumpedPacketSource(hci_device.read), 102 PumpedPacketSink(hci_device.write), 103 channel.close 104 ) 105 transport.start() 106 107 return transport 108