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trezor-firmware/python/src/trezorlib/transport/ble.py

266 lines
8.2 KiB

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2022 SatoshiLabs and contributors
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3
# as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the License along with this library.
# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
import asyncio
import logging
from dataclasses import dataclass
from multiprocessing import Pipe, Process
from multiprocessing.connection import Connection
from typing import TYPE_CHECKING, Any, Iterable, List, Optional
from . import TransportException
from .protocol import ProtocolBasedTransport, ProtocolV1
if TYPE_CHECKING:
from ..models import TrezorModel
LOG = logging.getLogger(__name__)
NUS_SERVICE_UUID = "6e400001-b5a3-f393-e0a9-e50e24dcca9e"
NUS_CHARACTERISTIC_RX = "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
NUS_CHARACTERISTIC_TX = "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
@dataclass
class Device:
address: str
name: str
connected: bool
class BleTransport(ProtocolBasedTransport):
ENABLED = True
PATH_PREFIX = "ble"
_ble = None
def __init__(self, mac_addr: str) -> None:
self.device = mac_addr
super().__init__(protocol=ProtocolV1(self, replen=244))
def get_path(self) -> str:
return "{}:{}".format(self.PATH_PREFIX, self.device)
def find_debug(self) -> "BleTransport":
return BleTransport(self.device)
@classmethod
def enumerate(
cls, _models: Optional[Iterable["TrezorModel"]] = None
) -> Iterable["BleTransport"]:
devices = cls.ble().lookup()
return [BleTransport(device.address) for device in devices if device.connected]
@classmethod
def _try_path(cls, path: str) -> "BleTransport":
devices = cls.enumerate(None)
devices = [d for d in devices if d.device == path]
if len(devices) == 0:
raise TransportException(f"No BLE device: {path}")
return devices[0]
@classmethod
def find_by_path(cls, path: str, prefix_search: bool = False) -> "BleTransport":
if not prefix_search:
raise TransportException
if prefix_search:
return super().find_by_path(path, prefix_search)
else:
raise TransportException(f"No BLE device: {path}")
def open(self) -> None:
self.ble().connect(self.device)
def close(self) -> None:
pass
def write_chunk(self, chunk: bytes) -> None:
self.ble().write(chunk)
def read_chunk(self) -> bytes:
chunk = self.ble().read()
# LOG.log(DUMP_PACKETS, f"received packet: {chunk.hex()}")
if len(chunk) != 64:
raise TransportException(f"Unexpected chunk size: {len(chunk)}")
return bytearray(chunk)
@classmethod
def ble(cls) -> "BleProxy":
if cls._ble is None:
cls._ble = BleProxy()
return cls._ble
class BleProxy:
pipe = None
process = None
def __init__(self):
if self.pipe is not None:
return
parent_pipe, child_pipe = Pipe()
self.pipe = parent_pipe
self.process = Process(target=BleAsync, args=(child_pipe,), daemon=True)
self.process.start()
def __getattr__(self, name: str):
def f(*args: Any, **kwargs: Any):
assert self.pipe is not None
self.pipe.send((name, args, kwargs))
result = self.pipe.recv()
if isinstance(result, BaseException):
raise result
return result
return f
class BleAsync:
def __init__(self, pipe: Connection):
asyncio.run(self.main(pipe))
async def main(self, pipe: Connection):
from ..tealblue import TealBlue
tb = await TealBlue.create()
# TODO: add cli option for mac_filter and pass it here
self.adapter = await tb.find_adapter()
# TODO: currently only one concurrent device is supported
# To support more devices, connect() needs to return a Connection and also has to
# spawn a task that will forward data between that Connection and rx,tx.
self.current = None
self.rx = None
self.tx = None
self.devices = {}
await self.lookup() # populate self.devices
LOG.debug("async BLE process started")
while True:
await ready(pipe)
cmd, args, kwargs = pipe.recv()
try:
result = await getattr(self, cmd)(*args, **kwargs)
except Exception as e:
LOG.exception("Error in async BLE process:")
await ready(pipe, write=True)
pipe.send(e)
break
else:
await ready(pipe, write=True)
pipe.send(result)
async def lookup(self) -> List[Device]:
self.devices.clear()
for device in await self.adapter.devices():
if NUS_SERVICE_UUID in device.UUIDs:
self.devices[device.address] = device
return [
Device(device.address, device.name, device.connected)
for device in self.devices.values()
]
async def scan(self) -> List[Device]:
LOG.debug("Initiating scan")
# TODO: configurable timeout
scanner = await self.adapter.scan(2)
self.devices.clear()
async with scanner:
async for device in scanner:
if NUS_SERVICE_UUID in device.UUIDs:
if device.address not in self.devices:
LOG.debug(f"scan: {device.address}: {device.name}")
self.devices[device.address] = device
return [
Device(device.address, device.name, device.connected)
for device in self.devices.values()
]
async def connect(self, address: str):
if self.current == address:
return
# elif self.current is not None:
# self.devices[self.current].disconnect()
ble_device = self.devices[address]
if not ble_device.connected:
LOG.info("Connecting to %s (%s)..." % (ble_device.name, ble_device.address))
await ble_device.connect()
else:
LOG.info("Connected to %s (%s)." % (ble_device.name, ble_device.address))
services = await ble_device.services()
nus_service = services[NUS_SERVICE_UUID]
self.rx, _mtu = await nus_service.characteristics[
NUS_CHARACTERISTIC_RX
].acquire(write=True)
self.tx, _mtu = await nus_service.characteristics[
NUS_CHARACTERISTIC_TX
].acquire()
self.current = address
async def disconnect(self):
if self.current is None:
return
ble_device = self.devices[self.current]
if ble_device.connected:
LOG.info(
"Disconnecting from %s (%s)..." % (ble_device.name, ble_device.address)
)
await ble_device.disconnect()
else:
LOG.info(
"Disconnected from %s (%s)." % (ble_device.name, ble_device.address)
)
self.current = None
self.rx = None
self.tx = None
async def read(self):
assert self.tx is not None
await ready(self.tx)
return self.tx.read()
async def write(self, chunk: bytes):
assert self.rx is not None
await ready(self.rx, write=True)
self.rx.write(chunk)
async def ready(f: Any, write: bool = False):
"""Asynchronously wait for file-like object to become ready for reading or writing."""
fd = f.fileno()
loop = asyncio.get_event_loop()
event = asyncio.Event()
if write:
def callback():
event.set()
loop.remove_writer(fd)
loop.add_writer(fd, callback)
else:
def callback():
event.set()
loop.remove_reader(fd)
loop.add_reader(fd, callback)
await event.wait()