Initial check-in of Linux virtual Me2Me.

remoting/tools/me2me_virtual_host.py

Index: remoting/tools/me2me_virtual_host.py
diff --git a/remoting/tools/me2me_virtual_host.py b/remoting/tools/me2me_virtual_host.py
new file mode 100755
index 0000000000000000000000000000000000000000..f8a8baaa3566e7e22119527f71aa5f5a4bc090ca
--- /dev/null
+++ b/remoting/tools/me2me_virtual_host.py
@@ -0,0 +1,317 @@
+#!/usr/bin/env python
+# Copyright (c) 2011 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.
+
+# Virtual Me2Me implementation.  This script runs and manages the processes
+# required for a Virtual Me2Me desktop, which are: X server, X desktop
+# session, and Host process.
+# This script is intended to run continuously as a background daemon
+# process, running under an ordinary (non-root) user account.
+
+import atexit
+import getpass
+import json
+import logging
+import os
+import random
+import signal
+import socket
+import subprocess
+import sys
+import time
+import urllib2
+import uuid
+
+# Local modules
+import gaia_auth
+import keygen
+
+REMOTING_COMMAND = "remoting_me2me_host"
+
+SCRIPT_PATH = os.path.dirname(sys.argv[0])
+if not SCRIPT_PATH:
+  SCRIPT_PATH = os.getcwd()
+
+# These are relative to SCRIPT_PATH.
+EXE_PATHS_TO_TRY = [
+    ".",
+    "../../out/Debug",
+    "../../out/Release"
+]
+
+CONFIG_DIR = os.path.expanduser("~/.config/chrome-remote-desktop")
+
+X_LOCK_FILE_TEMPLATE = "/tmp/.X%d-lock"
+FIRST_X_DISPLAY_NUMBER = 20
+
+X_AUTH_FILE = os.path.expanduser("~/.Xauthority")
+os.environ["XAUTHORITY"] = X_AUTH_FILE
+
+def locate_executable(exe_name):
+  for path in EXE_PATHS_TO_TRY:
+    exe_path = os.path.join(SCRIPT_PATH, path, exe_name)
+    if os.path.exists(exe_path):
+      return exe_path
+  raise Exception("Could not locate executable '%s'" % exe_name)
+
+g_desktops = []
+
+class Authentication:
+  """Manage authentication tokens for Chromoting/xmpp"""
+  def __init__(self, config_file):
+    self.config_file = config_file
+
+  def refresh_tokens(self):
+    print "Email:",
+    self.login = raw_input()
+    password = getpass.getpass("Password: ")
+
+    chromoting_auth = gaia_auth.GaiaAuthenticator('chromoting')
+    self.chromoting_auth_token = chromoting_auth.authenticate(self.login,
+                                                              password)
+
+    xmpp_authenticator = gaia_auth.GaiaAuthenticator('chromiumsync')
+    self.xmpp_auth_token = xmpp_authenticator.authenticate(self.login,
+                                                           password)
+
+  def load_config(self):
+    try:
+      settings_file = open(self.config_file, 'r')
+      data = json.load(settings_file)
+      settings_file.close()
+      self.login = data["xmpp_login"]
+      self.chromoting_auth_token = data["chromoting_auth_token"]
+      self.xmpp_auth_token = data["xmpp_auth_token"]
+    except:
+      return False
+    return True
+
+  def save_config(self):
+    data = {
+        "xmpp_login": self.login,
+        "chromoting_auth_token": self.chromoting_auth_token,
+        "xmpp_auth_token": self.xmpp_auth_token,
+    }
+    os.umask(0066) # Set permission mask for created file.
+    settings_file = open(self.config_file, 'w')
+    settings_file.write(json.dumps(data, indent=2))
+    settings_file.close()
+
+
+class Host:
+  """This manages the configuration for a host.
+
+  Callers should instantiate a Host object (passing in a filename where the
+  config will be kept), then should call either of the methods:
+
+  * create_config(auth): Create a new Host configuration and register it with
+  the Directory Service (the "auth" parameter is used to authenticate with the
+  Service).
+  * load_config(): Load a config from disk, with details of an existing Host
+  registration.
+
+  After calling create_config() (or making any config changes) the method
+  save_config() should be called to save the details to disk.
+  """
+
+  server = 'www.googleapis.com'
+  url = 'https://' + server + '/chromoting/v1/@me/hosts'
+
+  def __init__(self, config_file):
+    self.config_file = config_file
+
+  def create_config(self, auth):
+    self.host_id = str(uuid.uuid1())
+    logging.info("HostId: " + self.host_id)
+    self.host_name = socket.gethostname()
+    logging.info("HostName: " + self.host_name)
+
+    logging.info("Generating RSA key pair...")
+    (self.private_key, public_key) = keygen.generateRSAKeyPair()
+    logging.info("Done")
+
+    json_data = {
+        "data": {
+            "hostId": self.host_id,
+            "hostName": self.host_name,
+            "publicKey": public_key,
+        }
+    }
+    params = json.dumps(json_data)
+    headers = {
+        "Authorization": "GoogleLogin auth=" + auth.chromoting_auth_token,
+        "Content-Type": "application/json",
+    }
+
+    request = urllib2.Request(self.url, params, headers)
+    opener = urllib2.OpenerDirector()
+    opener.add_handler(urllib2.HTTPDefaultErrorHandler())
+
+    logging.info("Registering host with directory service...")
+    try:
+      res = urllib2.urlopen(request)
+      data = res.read()
+    except urllib2.HTTPError, err:
+      logging.error("Directory returned error: " + str(err))
+      logging.error(err.read())
+      sys.exit(1)
+    logging.info("Done")
+
+  def load_config(self):
+    try:
+      settings_file = open(self.config_file, 'r')
+      data = json.load(settings_file)
+      settings_file.close()
+      self.host_id = data["host_id"]
+      self.host_name = data["host_name"]
+      self.private_key = data["private_key"]
+    except:
+      return False
+    return True
+
+  def save_config(self):
+    data = {
+        "host_id": self.host_id,
+        "host_name": self.host_name,
+        "private_key": self.private_key,
+    }
+    os.umask(0066) # Set permission mask for created file.
+    settings_file = open(self.config_file, 'w')
+    settings_file.write(json.dumps(data, indent=2))
+    settings_file.close()
+
+
+def cleanup():
+  logging.info("Cleanup.")
+
+  for desktop in g_desktops:
+    if desktop.x_proc:
+      logging.info("Terminating Xvfb")
+      desktop.x_proc.terminate()
+
+def signal_handler(signum, stackframe):
+    # Exit cleanly so the atexit handler, cleanup(), gets called.
+    raise SystemExit
+
+
+class Desktop:
+  """Manage a single virtual desktop"""
+  def __init__(self):
+    self.x_proc = None
+    g_desktops.append(self)
+
+  @staticmethod
+  def get_unused_display_number():
+    """Return a candidate display number for which there is currently no
+    X Server lock file"""
+    display = FIRST_X_DISPLAY_NUMBER
+    while os.path.exists(X_LOCK_FILE_TEMPLATE % display):
+      display += 1
+    return display
+
+  def launch_x_server(self):
+    display = self.get_unused_display_number()
+    ret_code = subprocess.call("xauth add :%d . `mcookie`" % display,
+                               shell=True)
+    if ret_code != 0:
+      raise Exception("xauth failed with code %d" % ret_code)
+
+    logging.info("Starting Xvfb on display :%d" % display);
+    self.x_proc = subprocess.Popen(["Xvfb", ":%d" % display,
+                                    "-auth", X_AUTH_FILE,
+                                    "-nolisten", "tcp",
+                                    "-screen", "0", "1024x768x24",
+                                    ])
+    if not self.x_proc.pid:
+      raise Exception("Could not start Xvfb.")
+
+    # Create clean environment for new session, so it is cleanly separated from
+    # the user's console X session.
+    self.child_env = {"DISPLAY": ":%d" % display}
+    for key in [
+        "HOME",
+        "LOGNAME",
+        "PATH",
+        "SHELL",
+        "USER",
+        "USERNAME"]:
+      if os.environ.has_key(key):
+        self.child_env[key] = os.environ[key]
+
+    # Wait for X to be active.
+    for test in range(5):
+      proc = subprocess.Popen("xdpyinfo > /dev/null", env=self.child_env,
+                              shell=True)
+      pid, retcode = os.waitpid(proc.pid, 0)
+      if retcode == 0:
+        break
+      time.sleep(0.5)
+    if retcode != 0:
+      raise Exception("Could not connect to Xvfb.")
+    else:
+      logging.info("Xvfb is active.")
+
+  def launch_x_session(self):
+    # Start desktop session
+    session_proc = subprocess.Popen("/etc/X11/Xsession",
+                                    cwd=os.environ["HOME"],
+                                    env=self.child_env)
+    if not session_proc.pid:
+      raise Exception("Could not start X session")
+
+  def launch_host(self):
+    # Start remoting host
+    command = locate_executable(REMOTING_COMMAND)
+    self.host_proc = subprocess.Popen(command, env=self.child_env)
+    if not self.host_proc.pid:
+      raise Exception("Could not start remoting host")
+
+
+def main():
+  atexit.register(cleanup)
+
+  for s in [signal.SIGINT, signal.SIGTERM]:
+    signal.signal(s, signal_handler)
+
+  # Ensure full path to config directory exists.
+  if not os.path.exists(CONFIG_DIR):
+    os.makedirs(CONFIG_DIR, mode=0700)
+
+  auth = Authentication(os.path.join(CONFIG_DIR, "auth.json"))
+  if not auth.load_config():
+    try:
+      auth.refresh_tokens()
+    except:
+      logging.error("Authentication failed.")
+      return 1
+    auth.save_config()
+
+  host = Host(os.path.join(CONFIG_DIR, "host.json"))
+
+  if not host.load_config():
+    host.create_config(auth)
+    host.save_config()
+
+  logging.info("Using host_id: " + host.host_id)
+
+  desktop = Desktop()
+  desktop.launch_x_server()
+  desktop.launch_x_session()
+  desktop.launch_host()
+
+  while True:
+    pid, status = os.wait()
+    logging.info("wait() returned (%s,%s)" % (pid, status))
+
+    if pid == desktop.x_proc.pid:
+      logging.info("X server process terminated with code %d", status)
+      break
+
+    if pid == desktop.host_proc.pid:
+      logging.info("Host process terminated, relaunching")
+      desktop.launch_host()
+
+if __name__ == "__main__":
+  logging.basicConfig(level=logging.DEBUG)
+  sys.exit(main())