chrome/test/pyautolib/chromeos/suid_actions.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Helper script to perform actions as a super-user on ChromeOS.
   7
   8 Needs to be run with superuser privileges, typically using the
   9 suid_python binary.
  10
  11 Usage:
  12   sudo python suid_actions.py --action=CleanFlimflamDirs
  13 """
  14
  15 import optparse
  16 import os
  17 import shutil
  18 import subprocess
  19 import sys
  20 import time
  21
  22 sys.path.append('/usr/local')  # to import autotest libs.
  23 from autotest.cros import constants
  24 from autotest.cros import cryptohome
  25
  26 TEMP_BACKCHANNEL_FILE = '/tmp/pyauto_network_backchannel_file'
  27
  28
  29 class SuidAction(object):
  30   """Helper to perform some super-user actions on ChromeOS."""
  31
  32   def _ParseArgs(self):
  33     parser = optparse.OptionParser()
  34     parser.add_option(
  35         '-a', '--action', help='Action to perform.')
  36     self._options = parser.parse_args()[0]
  37     if not self._options.action:
  38       raise RuntimeError('No action specified.')
  39
  40   def Run(self):
  41     self._ParseArgs()
  42     assert os.geteuid() == 0, 'Needs superuser privileges.'
  43     handler = getattr(self, self._options.action)
  44     assert handler and callable(handler), \
  45         'No handler for %s' % self._options.action
  46     handler()
  47     return 0
  48
  49   ## Actions ##
  50   def CleanFlimflamDirs(self):
  51     """Clean the contents of all connection manager (shill/flimflam) profiles.
  52     """
  53     flimflam_dirs = ['/home/chronos/user/flimflam',
  54                      '/home/chronos/user/shill',
  55                      '/var/cache/flimflam',
  56                      '/var/cache/shill']
  57
  58     # The stop/start flimflam command should stop/start shill respectivly if
  59     # enabled.
  60     os.system('stop flimflam')
  61     try:
  62       for flimflam_dir in flimflam_dirs:
  63         if not os.path.exists(flimflam_dir):
  64           continue
  65         for item in os.listdir(flimflam_dir):
  66           path = os.path.join(flimflam_dir, item)
  67           if os.path.isdir(path):
  68             shutil.rmtree(path)
  69           else:
  70             os.remove(path)
  71     finally:
  72       os.system('start flimflam')
  73       # TODO(stanleyw): crosbug.com/29421 This method should wait until
  74       # flimflam/shill is fully initialized and accessible via DBus again.
  75       # Otherwise, there is a race conditions and subsequent accesses to
  76       # flimflam/shill may fail. Until this is fixed, waiting for the
  77       # resolv.conf file to be created is better than nothing.
  78       begin = time.time()
  79       while not os.path.exists(constants.RESOLV_CONF_FILE):
  80         if time.time() - begin > 10:
  81           raise RuntimeError('Timeout while waiting for flimflam/shill start.')
  82         time.sleep(.25)
  83
  84   def RemoveAllCryptohomeVaults(self):
  85     """Remove any existing cryptohome vaults."""
  86     cryptohome.remove_all_vaults()
  87
  88   def _GetEthInterfaces(self):
  89     """Returns a list of the eth* interfaces detected by the device."""
  90     # Assumes ethernet interfaces all have "eth" in the name.
  91     import pyudev
  92     return sorted([iface.sys_name for iface in
  93                    pyudev.Context().list_devices(subsystem='net')
  94                    if 'eth' in iface.sys_name])
  95
  96   def _Renameif(self, old_iface, new_iface, mac_address):
  97     """Renames the interface with mac_address from old_iface to new_iface.
  98
  99     Args:
 100       old_iface: The name of the interface you want to change.
 101       new_iface: The name of the interface you want to change to.
 102       mac_address:  The mac address of the interface being changed.
 103     """
 104     subprocess.call(['stop', 'flimflam'])
 105     subprocess.call(['ifconfig', old_iface, 'down'])
 106     subprocess.call(['nameif', new_iface, mac_address])
 107     subprocess.call(['ifconfig', new_iface, 'up'])
 108     subprocess.call(['start', 'flimflam'])
 109
 110     # Check and make sure interfaces have been renamed
 111     eth_ifaces = self._GetEthInterfaces()
 112     if new_iface not in eth_ifaces:
 113       raise RuntimeError('Interface %s was not renamed to %s' %
 114                          (old_iface, new_iface))
 115     elif old_iface in eth_ifaces:
 116       raise RuntimeError('Old iface %s is still present' % old_iface)
 117
 118   def SetupBackchannel(self):
 119     """Renames the connected ethernet interface to eth_test for offline mode
 120        testing.  Does nothing if no connected interface is found.
 121     """
 122     # Return the interface with ethernet connected or returns if none found.
 123     for iface in self._GetEthInterfaces():
 124       with open('/sys/class/net/%s/operstate' % iface, 'r') as fp:
 125         if 'up' in fp.read():
 126           eth_iface = iface
 127           break
 128     else:
 129       return
 130
 131     # Write backup file to be used by TeardownBackchannel to restore the
 132     # interface names.
 133     with open(TEMP_BACKCHANNEL_FILE, 'w') as fpw:
 134       with open('/sys/class/net/%s/address' % eth_iface) as fp:
 135         mac_address = fp.read().strip()
 136         fpw.write('%s, %s' % (eth_iface, mac_address))
 137
 138     self._Renameif(eth_iface, 'eth_test', mac_address)
 139
 140   def TeardownBackchannel(self):
 141     """Restores the eth interface names if SetupBackchannel was called."""
 142     if not os.path.isfile(TEMP_BACKCHANNEL_FILE):
 143       return
 144
 145     with open(TEMP_BACKCHANNEL_FILE, 'r') as fp:
 146       eth_iface, mac_address = fp.read().split(',')
 147
 148     self._Renameif('eth_test', eth_iface, mac_address)
 149     os.remove(TEMP_BACKCHANNEL_FILE)
 150
 151
 152 if __name__ == '__main__':
 153   sys.exit(SuidAction().Run())