#!/usr/bin/env python3
#
# Copyright 2019 The usbmon-tools Authors
# Copyright 2020 The glucometerutils Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# SPDX-License-Identifier: Apache-2.0
import argparse
import logging
import sys
import usbmon
import usbmon.chatter
import usbmon.pcapng
_KEEPALIVE_TYPE = 0x22
_UNENCRYPTED_TYPES = (
0x01, 0x04, 0x05, 0x06, 0x0c, 0x0d,
0x14, 0x15,
0x33, 0x34, 0x35,
0x71,
_KEEPALIVE_TYPE,
)
def main():
if sys.version_info < (3, 7):
raise Exception(
'Unsupported Python version, please use at least Python 3.7.')
parser = argparse.ArgumentParser()
parser.add_argument(
'--addr_prefix', action='store', type=str, required=True,
help=('Prefix match applied to the device address in text format. '
'Only packets with source or destination matching this prefix '
'will be printed out.'))
parser.add_argument(
'--vlog', action='store', required=False, type=int,
help=('Python logging level. See the levels at '
'https://docs.python.org/3/library/logging.html#logging-levels'))
parser.add_argument(
'--libre2', action='store_true',
help=('Whether to expect the capture coming from a Libre 2 device. '
'Libre 2 devices encrypt some of the messages, and as such they '
'will be dumped with the undecoded length as well.'))
parser.add_argument(
'--print_keepalive', action='store_true',
help=('Whether to print the keepalive messages sent by the device. '
'Keepalive messages are usually safely ignored.'))
parser.add_argument(
'pcap_file', action='store', type=str,
help='Path to the pcapng file with the USB capture.')
args = parser.parse_args()
logging.basicConfig(level=args.vlog)
session = usbmon.pcapng.parse_file(args.pcap_file, retag_urbs=False)
for first, second in session.in_pairs():
# Ignore stray callbacks/errors.
if not first.type == usbmon.constants.PacketType.SUBMISSION:
continue
if not first.address.startswith(args.addr_prefix):
# No need to check second, they will be linked.
continue
if first.xfer_type == usbmon.constants.XferType.INTERRUPT:
pass
elif (first.xfer_type == usbmon.constants.XferType.CONTROL and
not first.setup_packet or
first.setup_packet.type == usbmon.setup.Type.CLASS):
pass
else:
continue
if first.direction == usbmon.constants.Direction.OUT:
packet = first
else:
packet = second
if not packet.payload:
continue
assert len(packet.payload) >= 2
message_type = packet.payload[0]
if message_type == _KEEPALIVE_TYPE and not args.print_keepalive:
continue
if args.libre2 and message_type not in _UNENCRYPTED_TYPES:
# On Libre 2 (expected encrypted communication), we ignore the
# message_length and we keep it with the whole message.
message_type = f'x{message_type:02x}'
message = packet.payload[1:]
else:
message_length = packet.payload[1]
message_type = f' {message_type:02x}'
message = packet.payload[2:2+message_length]
print(usbmon.chatter.dump_bytes(
packet.direction,
message,
prefix=f'[{message_type}]',
print_empty=True,
), '\n')
if __name__ == "__main__":
main()
