[android] Upstream / sync most of build/android and build/android/pylib.

build/android/pylib/forwarder.py

+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import logging
+import os
+import pexpect
+import re
+import sys
+
+import android_commands
+from constants import CHROME_DIR
+
+class Forwarder(object):
+  """Class to manage port forwards from the device to the host."""
+
+  _FORWARDER_PATH = '/data/local/tmp/forwarder'
+  _TIMEOUT_SECS = 30
+
+  def __init__(self, adb, port_pairs, tool, host_name):
+    """Forwards TCP ports on the device back to the host.
+
+    Works like adb forward, but in reverse.
+
+    Args:
+      adb: Instance of AndroidCommands for talking to the device.
+      port_pairs: A list of tuples (device_port, host_port) to forward. Note
+                 that you can specify 0 as a device_port, in which case a
+                 port will by dynamically assigned on the device. You can
+                 get the number of the assigned port using the
+                 DevicePortForHostPort method.
+      tool: Tool class to use to get wrapper, if necessary, for executing the
+            forwarder (see valgrind_tools.py).
+      host_name: Optional. Address to forward to, must be addressable from the
+                 host machine. Usually this is omitted and loopback is used.
+
+    Raises:
+      Exception on failure to forward the port.
+    """
+    self._adb = adb
+    self._host_to_device_port_map = dict()
+    self._process = None
+    adb.PushIfNeeded(
+        os.path.join(CHROME_DIR, 'out', 'Release', 'forwarder'),
+        Forwarder._FORWARDER_PATH)
+    forward_string = ['%d:%d:%s' %
+                      (device, host, host_name) for device, host in port_pairs]
+
+    # Kill off any existing forwarders on conflicting non-dynamically allocated
+    # ports.
+    for device_port, _ in port_pairs:
+      if device_port != 0:
+        self._KillForwardersUsingDevicePort(device_port)
+
+    logging.info('Forwarding ports: %s' % (forward_string))
+    process = pexpect.spawn(
+      'adb', ['-s', adb._adb.GetSerialNumber(),
+              'shell', '%s %s -D %s' % (
+          tool.GetUtilWrapper(), Forwarder._FORWARDER_PATH,
+          ' '.join(forward_string))])
+
+    # Read the output of the command to determine which device ports where
+    # forwarded to which host ports (necessary if
+    success_re = re.compile('Forwarding device port (\d+) to host (\d+):')
+    failure_re = re.compile('Couldn\'t start forwarder server for port spec: '
+                            '(\d+):(\d+)')
+    for pair in port_pairs:
+      index = process.expect([success_re, failure_re, pexpect.EOF,
+                              pexpect.TIMEOUT],
+                             Forwarder._TIMEOUT_SECS)
+      if index == 0:
+        # Success
+        device_port = int(process.match.group(1))
+        host_port = int(process.match.group(2))
+        self._host_to_device_port_map[host_port] = device_port
+        logging.info("Forwarding device port: %d to host port: %d." %
+                     (device_port, host_port))
+      elif index == 1:
+        # Failure
+        device_port = int(process.match.group(1))
+        host_port = int(process.match.group(2))
+        process.close()
+        raise Exception('Failed to forward port %d to %d' % (device_port,
+                                                             host_port))
+      elif index == 2:
+        logging.error(process.before)
+        process.close()
+        raise Exception('Unexpected EOF while trying to forward ports %s' %
+                        port_pairs)
+      elif index == 3:
+        logging.error(process.before)
+        process.close()
+        raise Exception('Timeout while trying to forward ports %s' % port_pairs)
+
+    self._process = process
+
+  def _KillForwardersUsingDevicePort(self, device_port):
+    """Check if the device port is in use and if it is try to terminate the
+       forwarder process (if any) that may already be forwarding it"""
+    processes = self._adb.ProcessesUsingDevicePort(device_port)
+    for pid, name in processes:
+      if name == 'forwarder':
+        logging.warning(
+            'Killing forwarder process with pid %d using device_port %d' % (
+                 pid, device_port))
+        self._adb.RunShellCommand('kill %d' % pid)
+      else:
+        logging.error(
+             'Not killing process with pid %d (%s) using device_port %d' % (
+                 pid, name, device_port))
+
+  def DevicePortForHostPort(self, host_port):
+    """Get the device port that corresponds to a given host port."""
+    return self._host_to_device_port_map.get(host_port)
+
+  def Close(self):
+    """Terminate the forwarder process."""
+    if self._process:
+      self._process.close()
+      self._process = None