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trezor-firmware/trezorlib/transport/__init__.py
matejcik 54f1599a5a regenerate license headers
This clarifies the intent: the project is licenced under terms
of LGPL version 3 only, but the standard headers cover only "3 or later",
so we had to rewrite them.

In the same step, we removed author information from individual files
in favor of "SatoshiLabs and contributors", and include an AUTHORS
file that lists the contributors.

Apologies to those whose names are missing; please contact us if you wish
to add your info to the AUTHORS file.
2018-06-21 16:49:13 +02:00

121 lines
4.1 KiB
Python

# This file is part of the Trezor project.
#
# Copyright (C) 2012-2018 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 importlib
import logging
from typing import Iterable, Type, List, Set
LOG = logging.getLogger(__name__)
class TransportException(Exception):
pass
class Transport(object):
def __init__(self):
self.session_counter = 0
def __str__(self):
return self.get_path()
def get_path(self):
return '{}:{}'.format(self.PATH_PREFIX, self.device)
def session_begin(self):
if self.session_counter == 0:
self.open()
self.session_counter += 1
def session_end(self):
self.session_counter = max(self.session_counter - 1, 0)
if self.session_counter == 0:
self.close()
def open(self):
raise NotImplementedError
def close(self):
raise NotImplementedError
@classmethod
def enumerate(cls):
raise NotImplementedError
@classmethod
def find_by_path(cls, path, prefix_search=False):
for device in cls.enumerate():
if path is None or device.get_path() == path \
or (prefix_search and device.get_path().startswith(path)):
return device
raise TransportException('{} device not found: {}'.format(cls.PATH_PREFIX, path))
def all_transports() -> Iterable[Type[Transport]]:
transports = set() # type: Set[Type[Transport]]
for modname in ("bridge", "hid", "udp", "webusb"):
try:
# Import the module and find the Transport class.
# To avoid iterating over every item, the module should assign its Transport class
# to a constant named TRANSPORT.
module = importlib.import_module("." + modname, __name__)
try:
transports.add(getattr(module, "TRANSPORT"))
except AttributeError:
LOG.warning("Skipping broken module {}".format(modname))
except ImportError as e:
LOG.info("Failed to import module {}: {}".format(modname, e))
return transports
def enumerate_devices() -> Iterable[Transport]:
devices = [] # type: List[Transport]
for transport in all_transports():
try:
found = transport.enumerate()
LOG.info("Enumerating {}: found {} devices".format(transport.__name__, len(found)))
devices.extend(found)
except NotImplementedError:
LOG.error("{} does not implement device enumeration".format(transport.__name__))
except Exception as e:
LOG.error("Failed to enumerate {}. {}: {}".format(transport.__name__, e.__class__.__name__, e))
return devices
def get_transport(path: str = None, prefix_search: bool = False) -> Transport:
if path is None:
try:
return next(iter(enumerate_devices()))
except IndexError:
raise Exception("No TREZOR device found") from None
# Find whether B is prefix of A (transport name is part of the path)
# or A is prefix of B (path is a prefix, or a name, of transport).
# This naively expects that no two transports have a common prefix.
def match_prefix(a: str, b: str) -> bool:
return a.startswith(b) or b.startswith(a)
LOG.info("looking for device by {}: {}".format("prefix" if prefix_search else "full path", path))
transports = [t for t in all_transports() if match_prefix(path, t.PATH_PREFIX)]
if transports:
return transports[0].find_by_path(path, prefix_search=prefix_search)
raise Exception("Could not find device by path: {}".format(path))