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trezor-firmware/trezorlib/transport/__init__.py
matejcik 5edcea9ba6
transport: fix all_transports when required modules are missing (#232)
This lets the library work without libusb or hidapi (`--disable-libusb`, `--disable-hidapi`).
2018-03-09 10:58:24 +01:00

119 lines
3.4 KiB
Python

# This file is part of the TREZOR project.
#
# Copyright (C) 2012-2016 Marek Palatinus <slush@satoshilabs.com>
# Copyright (C) 2012-2016 Pavol Rusnak <stick@satoshilabs.com>
# Copyright (C) 2016 Jochen Hoenicke <hoenicke@gmail.com>
#
# This library is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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 GNU Lesser General Public License
# along with this library. If not, see <http://www.gnu.org/licenses/>.
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():
transports = []
try:
from .bridge import BridgeTransport
transports.append(BridgeTransport)
except:
pass
try:
from .hid import HidTransport
transports.append(HidTransport)
except:
pass
try:
from .udp import UdpTransport
transports.append(UdpTransport)
except:
pass
try:
from .webusb import WebUsbTransport
transports.append(WebUsbTransport)
except:
pass
return transports
def enumerate_devices():
return [device
for transport in all_transports()
for device in transport.enumerate()]
def get_transport(path=None, prefix_search=False):
if path is None:
try:
return enumerate_devices()[0]
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, b):
return a.startswith(b) or b.startswith(a)
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("Unknown path prefix '%s'" % prefix)