sdk/platform-tools/systrace/catapult/devil/devil/utils/lsusb.py

   1 # Copyright 2015 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import logging
   6 import re
   7
   8 from devil.utils import cmd_helper
   9
  10 logger = logging.getLogger(__name__)
  11
  12 _COULDNT_OPEN_ERROR_RE = re.compile(r'Couldn\'t open device.*')
  13 _INDENTATION_RE = re.compile(r'^( *)')
  14 _LSUSB_BUS_DEVICE_RE = re.compile(r'^Bus (\d{3}) Device (\d{3}): (.*)')
  15 _LSUSB_ENTRY_RE = re.compile(r'^ *([^ ]+) +([^ ]+) *([^ ].*)?$')
  16 _LSUSB_GROUP_RE = re.compile(r'^ *([^ ]+.*):$')
  17
  18
  19 def _lsusbv_on_device(bus_id, dev_id):
  20   """Calls lsusb -v on device."""
  21   _, raw_output = cmd_helper.GetCmdStatusAndOutputWithTimeout(
  22       ['lsusb', '-v', '-s', '%s:%s' % (bus_id, dev_id)], timeout=10)
  23
  24   device = {'bus': bus_id, 'device': dev_id}
  25   depth_stack = [device]
  26
  27   # This builds a nested dict -- a tree, basically -- that corresponds
  28   # to the lsusb output. It looks first for a line containing
  29   #
  30   #   "Bus <bus number> Device <device number>: ..."
  31   #
  32   # and uses that to create the root node. It then parses all remaining
  33   # lines as a tree, with the indentation level determining the
  34   # depth of the new node.
  35   #
  36   # This expects two kinds of lines:
  37   #   - "groups", which take the form
  38   #       "<Group name>:"
  39   #     and typically have children, and
  40   #   - "entries", which take the form
  41   #       "<entry name>   <entry value>  <possible entry description>"
  42   #     and typically do not have children (but can).
  43   #
  44   # This maintains a stack containing all current ancestor nodes in
  45   # order to add new nodes to the proper place in the tree.
  46   # The stack is added to when a new node is parsed. Nodes are removed
  47   # from the stack when they are either at the same indentation level as
  48   # or a deeper indentation level than the current line.
  49   #
  50   # e.g. the following lsusb output:
  51   #
  52   # Bus 123 Device 456: School bus
  53   # Device Descriptor:
  54   #   bDeviceClass 5 Actual School Bus
  55   #   Configuration Descriptor:
  56   #     bLength 20 Rows
  57   #
  58   # would produce the following dict:
  59   #
  60   # {
  61   #   'bus': 123,
  62   #   'device': 456,
  63   #   'desc': 'School bus',
  64   #   'Device Descriptor': {
  65   #     'bDeviceClass': {
  66   #       '_value': '5',
  67   #       '_desc': 'Actual School Bus',
  68   #     },
  69   #     'Configuration Descriptor': {
  70   #       'bLength': {
  71   #         '_value': '20',
  72   #         '_desc': 'Rows',
  73   #       },
  74   #     },
  75   #   }
  76   # }
  77   for line in raw_output.splitlines():
  78     # Ignore blank lines.
  79     if not line:
  80       continue
  81     # Filter out error mesage about opening device.
  82     if _COULDNT_OPEN_ERROR_RE.match(line):
  83       continue
  84     # Find start of device information.
  85     m = _LSUSB_BUS_DEVICE_RE.match(line)
  86     if m:
  87       if m.group(1) != bus_id:
  88         logger.warning(
  89             'Expected bus_id value: %r, seen %r', bus_id, m.group(1))
  90       if m.group(2) != dev_id:
  91         logger.warning(
  92             'Expected dev_id value: %r, seen %r', dev_id, m.group(2))
  93       device['desc'] = m.group(3)
  94       continue
  95
  96     # Skip any lines that aren't indented, as they're not part of the
  97     # device descriptor.
  98     indent_match = _INDENTATION_RE.match(line)
  99     if not indent_match:
 100       continue
 101
 102     # Determine the indentation depth.
 103     depth = 1 + len(indent_match.group(1)) / 2
 104     if depth > len(depth_stack):
 105       logger.error(
 106           'lsusb parsing error: unexpected indentation: "%s"', line)
 107       continue
 108
 109     # Pop everything off the depth stack that isn't a parent of
 110     # this element.
 111     while depth < len(depth_stack):
 112       depth_stack.pop()
 113
 114     cur = depth_stack[-1]
 115
 116     m = _LSUSB_GROUP_RE.match(line)
 117     if m:
 118       new_group = {}
 119       cur[m.group(1)] = new_group
 120       depth_stack.append(new_group)
 121       continue
 122
 123     m = _LSUSB_ENTRY_RE.match(line)
 124     if m:
 125       new_entry = {
 126         '_value': m.group(2),
 127         '_desc': m.group(3),
 128       }
 129       cur[m.group(1)] = new_entry
 130       depth_stack.append(new_entry)
 131       continue
 132
 133     logger.error('lsusb parsing error: unrecognized line: "%s"', line)
 134
 135   return device
 136
 137 def lsusb():
 138   """Call lsusb and return the parsed output."""
 139   _, lsusb_list_output = cmd_helper.GetCmdStatusAndOutputWithTimeout(
 140       ['lsusb'], timeout=10)
 141   devices = []
 142   for line in lsusb_list_output.splitlines():
 143     m = _LSUSB_BUS_DEVICE_RE.match(line)
 144     if m:
 145       bus_num = m.group(1)
 146       dev_num = m.group(2)
 147       try:
 148         devices.append(_lsusbv_on_device(bus_num, dev_num))
 149       except cmd_helper.TimeoutError:
 150         # Will be blacklisted if it is in expected device file, but times out.
 151         logger.info('lsusb -v %s:%s timed out.', bus_num, dev_num)
 152   return devices
 153
 154 def raw_lsusb():
 155   return cmd_helper.GetCmdOutput(['lsusb'])
 156
 157 def get_lsusb_serial(device):
 158   try:
 159     return device['Device Descriptor']['iSerial']['_desc']
 160   except KeyError:
 161     return None
 162
 163 def _is_android_device(device):
 164   try:
 165     # Hubs are not android devices.
 166     if device['Device Descriptor']['bDeviceClass']['_value'] == '9':
 167       return False
 168   except KeyError:
 169     pass
 170   return get_lsusb_serial(device) is not None
 171
 172 def get_android_devices():
 173   android_devices = (d for d in lsusb() if _is_android_device(d))
 174   return [get_lsusb_serial(d) for d in android_devices]