media/webrtc/trunk/build/android/pylib/forwarder.py

   1 # Copyright (c) 2012 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 os
   7 import pexpect
   8 import re
   9 import sys
  10
  11 import android_commands
  12 from constants import CHROME_DIR
  13
  14 class Forwarder(object):
  15   """Class to manage port forwards from the device to the host."""
  16
  17   _FORWARDER_PATH = '/data/local/tmp/forwarder'
  18   _TIMEOUT_SECS = 30
  19
  20   def __init__(self, adb, port_pairs, tool, host_name, build_type):
  21     """Forwards TCP ports on the device back to the host.
  22
  23     Works like adb forward, but in reverse.
  24
  25     Args:
  26       adb: Instance of AndroidCommands for talking to the device.
  27       port_pairs: A list of tuples (device_port, host_port) to forward. Note
  28                  that you can specify 0 as a device_port, in which case a
  29                  port will by dynamically assigned on the device. You can
  30                  get the number of the assigned port using the
  31                  DevicePortForHostPort method.
  32       tool: Tool class to use to get wrapper, if necessary, for executing the
  33             forwarder (see valgrind_tools.py).
  34       host_name: Address to forward to, must be addressable from the
  35                  host machine. Usually use loopback '127.0.0.1'.
  36       build_type: 'Release' or 'Debug'.
  37
  38     Raises:
  39       Exception on failure to forward the port.
  40     """
  41     self._adb = adb
  42     self._host_to_device_port_map = dict()
  43     self._process = None
  44     adb.PushIfNeeded(
  45         os.path.join(CHROME_DIR, 'out', build_type, 'forwarder'),
  46         Forwarder._FORWARDER_PATH)
  47     forward_string = ['%d:%d:%s' %
  48                       (device, host, host_name) for device, host in port_pairs]
  49
  50     # Kill off any existing forwarders on conflicting non-dynamically allocated
  51     # ports.
  52     for device_port, _ in port_pairs:
  53       if device_port != 0:
  54         self._KillForwardersUsingDevicePort(device_port)
  55
  56     logging.info('Forwarding ports: %s' % (forward_string))
  57     process = pexpect.spawn(
  58       'adb', ['-s', adb._adb.GetSerialNumber(),
  59               'shell', '%s %s -D %s' % (
  60           tool.GetUtilWrapper(), Forwarder._FORWARDER_PATH,
  61           ' '.join(forward_string))])
  62
  63     # Read the output of the command to determine which device ports where
  64     # forwarded to which host ports (necessary if
  65     success_re = re.compile('Forwarding device port (\d+) to host (\d+):')
  66     failure_re = re.compile('Couldn\'t start forwarder server for port spec: '
  67                             '(\d+):(\d+)')
  68     for pair in port_pairs:
  69       index = process.expect([success_re, failure_re, pexpect.EOF,
  70                               pexpect.TIMEOUT],
  71                              Forwarder._TIMEOUT_SECS)
  72       if index == 0:
  73         # Success
  74         device_port = int(process.match.group(1))
  75         host_port = int(process.match.group(2))
  76         self._host_to_device_port_map[host_port] = device_port
  77         logging.info("Forwarding device port: %d to host port: %d." %
  78                      (device_port, host_port))
  79       elif index == 1:
  80         # Failure
  81         device_port = int(process.match.group(1))
  82         host_port = int(process.match.group(2))
  83         process.close()
  84         raise Exception('Failed to forward port %d to %d' % (device_port,
  85                                                              host_port))
  86       elif index == 2:
  87         logging.error(process.before)
  88         process.close()
  89         raise Exception('Unexpected EOF while trying to forward ports %s' %
  90                         port_pairs)
  91       elif index == 3:
  92         logging.error(process.before)
  93         process.close()
  94         raise Exception('Timeout while trying to forward ports %s' % port_pairs)
  95
  96     self._process = process
  97
  98   def _KillForwardersUsingDevicePort(self, device_port):
  99     """Check if the device port is in use and if it is try to terminate the
 100        forwarder process (if any) that may already be forwarding it"""
 101     processes = self._adb.ProcessesUsingDevicePort(device_port)
 102     for pid, name in processes:
 103       if name == 'forwarder':
 104         logging.warning(
 105             'Killing forwarder process with pid %d using device_port %d' % (
 106                  pid, device_port))
 107         self._adb.RunShellCommand('kill %d' % pid)
 108       else:
 109         logging.error(
 110              'Not killing process with pid %d (%s) using device_port %d' % (
 111                  pid, name, device_port))
 112
 113   def DevicePortForHostPort(self, host_port):
 114     """Get the device port that corresponds to a given host port."""
 115     return self._host_to_device_port_map.get(host_port)
 116
 117   def Close(self):
 118     """Terminate the forwarder process."""
 119     if self._process:
 120       self._process.close()
 121       self._process = None