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Samples/nacl_sdk/RakNet_NativeClient/httpd.py

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+#!/usr/bin/env python
+# 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 BaseHTTPServer
+import imp
+import logging
+import multiprocessing
+import optparse
+import os
+import SimpleHTTPServer  # pylint: disable=W0611
+import socket
+import sys
+import time
+import urlparse
+
+
+SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
+NACL_SDK_ROOT = os.path.dirname(SCRIPT_DIR)
+
+
+# We only run from the examples directory so that not too much is exposed
+# via this HTTP server.  Everything in the directory is served, so there should
+# never be anything potentially sensitive in the serving directory, especially
+# if the machine might be a multi-user machine and not all users are trusted.
+# We only serve via the loopback interface.
+def SanityCheckDirectory(dirname):
+  abs_serve_dir = os.path.abspath(dirname)
+
+  # Verify we don't serve anywhere above NACL_SDK_ROOT.
+  if abs_serve_dir[:len(NACL_SDK_ROOT)] == NACL_SDK_ROOT:
+    return
+  logging.error('For security, httpd.py should only be run from within the')
+  logging.error('example directory tree.')
+  logging.error('Attempting to serve from %s.' % abs_serve_dir)
+  logging.error('Run with --no_dir_check to bypass this check.')
+  sys.exit(1)
+
+
+class PluggableHTTPServer(BaseHTTPServer.HTTPServer):
+  def __init__(self, *args, **kwargs):
+    BaseHTTPServer.HTTPServer.__init__(self, *args)
+    self.serve_dir = kwargs.get('serve_dir', '.')
+    self.test_mode = kwargs.get('test_mode', False)
+    self.delegate_map = {}
+    self.running = True
+    self.result = 0
+
+  def Shutdown(self, result=0):
+    self.running = False
+    self.result = result
+
+
+class PluggableHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+  def _FindDelegateAtPath(self, dirname):
+    # First check the cache...
+    logging.debug('Looking for cached delegate in %s...' % dirname)
+    handler_script = os.path.join(dirname, 'handler.py')
+
+    if dirname in self.server.delegate_map:
+      result = self.server.delegate_map[dirname]
+      if result is None:
+        logging.debug('Found None.')
+      else:
+        logging.debug('Found delegate.')
+      return result
+
+    # Don't have one yet, look for one.
+    delegate = None
+    logging.debug('Testing file %s for existence...' % handler_script)
+    if os.path.exists(handler_script):
+      logging.debug(
+          'File %s exists, looking for HTTPRequestHandlerDelegate.' %
+          handler_script)
+
+      module = imp.load_source('handler', handler_script)
+      delegate_class = getattr(module, 'HTTPRequestHandlerDelegate', None)
+      delegate = delegate_class()
+      if not delegate:
+        logging.warn(
+            'Unable to find symbol HTTPRequestHandlerDelegate in module %s.' %
+            handler_script)
+
+    return delegate
+
+  def _FindDelegateForURLRecurse(self, cur_dir, abs_root):
+    delegate = self._FindDelegateAtPath(cur_dir)
+    if not delegate:
+      # Didn't find it, try the parent directory, but stop if this is the server
+      # root.
+      if cur_dir != abs_root:
+        parent_dir = os.path.dirname(cur_dir)
+        delegate = self._FindDelegateForURLRecurse(parent_dir, abs_root)
+
+    logging.debug('Adding delegate to cache for %s.' % cur_dir)
+    self.server.delegate_map[cur_dir] = delegate
+    return delegate
+
+  def _FindDelegateForURL(self, url_path):
+    path = self.translate_path(url_path)
+    if os.path.isdir(path):
+      dirname = path
+    else:
+      dirname = os.path.dirname(path)
+
+    abs_serve_dir = os.path.abspath(self.server.serve_dir)
+    delegate = self._FindDelegateForURLRecurse(dirname, abs_serve_dir)
+    if not delegate:
+      logging.info('No handler found for path %s. Using default.' % url_path)
+    return delegate
+
+  def _SendNothingAndDie(self, result=0):
+    self.send_response(200, 'OK')
+    self.send_header('Content-type', 'text/html')
+    self.send_header('Content-length', '0')
+    self.end_headers()
+    self.server.Shutdown(result)
+
+  def send_head(self):
+    delegate = self._FindDelegateForURL(self.path)
+    if delegate:
+      return delegate.send_head(self)
+    return self.base_send_head()
+
+  def base_send_head(self):
+    return SimpleHTTPServer.SimpleHTTPRequestHandler.send_head(self)
+
+  def do_GET(self):
+    # TODO(binji): pyauto tests use the ?quit=1 method to kill the server.
+    # Remove this when we kill the pyauto tests.
+    _, _, _, query, _ = urlparse.urlsplit(self.path)
+    if query:
+      params = urlparse.parse_qs(query)
+      if '1' in params.get('quit', None):
+        self._SendNothingAndDie()
+        return
+
+    delegate = self._FindDelegateForURL(self.path)
+    if delegate:
+      return delegate.do_GET(self)
+    return self.base_do_GET()
+
+  def base_do_GET(self):
+    return SimpleHTTPServer.SimpleHTTPRequestHandler.do_GET(self)
+
+  def do_POST(self):
+    delegate = self._FindDelegateForURL(self.path)
+    if delegate:
+      return delegate.do_POST(self)
+    return self.base_do_POST()
+
+  def base_do_POST(self):
+    if self.server.test_mode:
+      if self.path == '/ok':
+        self._SendNothingAndDie(0)
+      elif self.path == '/fail':
+        self._SendNothingAndDie(1)
+
+
+class LocalHTTPServer(object):
+  """Class to start a local HTTP server as a child process."""
+
+  def __init__(self, dirname, port, test_mode):
+    parent_conn, child_conn = multiprocessing.Pipe()
+    self.process = multiprocessing.Process(
+        target=_HTTPServerProcess,
+        args=(child_conn, dirname, port, {
+          'serve_dir': dirname,
+          'test_mode': test_mode,
+        }))
+    self.process.start()
+    if parent_conn.poll(10):  # wait 10 seconds
+      self.port = parent_conn.recv()
+    else:
+      raise Exception('Unable to launch HTTP server.')
+
+    self.conn = parent_conn
+
+  def ServeForever(self):
+    """Serve until the child HTTP process tells us to stop.
+
+    Returns:
+      The result from the child (as an errorcode), or 0 if the server was
+      killed not by the child (by KeyboardInterrupt for example).
+    """
+    child_result = 0
+    try:
+      # Block on this pipe, waiting for a response from the child process.
+      child_result = self.conn.recv()
+    except KeyboardInterrupt:
+      pass
+    finally:
+      self.Shutdown()
+    return child_result
+
+  def ServeUntilSubprocessDies(self, process):
+    """Serve until the child HTTP process tells us to stop or |subprocess| dies.
+
+    Returns:
+      The result from the child (as an errorcode), or 0 if |subprocess| died,
+      or the server was killed some other way (by KeyboardInterrupt for
+      example).
+    """
+    child_result = 0
+    try:
+      while True:
+        if process.poll() is not None:
+          child_result = 0
+          break
+        if self.conn.poll():
+          child_result = self.conn.recv()
+          break
+        time.sleep(0)
+    except KeyboardInterrupt:
+      pass
+    finally:
+      self.Shutdown()
+    return child_result
+
+  def Shutdown(self):
+    """Send a message to the child HTTP server process and wait for it to
+        finish."""
+    self.conn.send(False)
+    self.process.join()
+
+  def GetURL(self, rel_url):
+    """Get the full url for a file on the local HTTP server.
+
+    Args:
+      rel_url: A URL fragment to convert to a full URL. For example,
+          GetURL('foobar.baz') -> 'http://localhost:1234/foobar.baz'
+    """
+    return 'http://localhost:%d/%s' % (self.port, rel_url)
+
+
+def _HTTPServerProcess(conn, dirname, port, server_kwargs):
+  """Run a local httpserver with the given port or an ephemeral port.
+
+  This function assumes it is run as a child process using multiprocessing.
+
+  Args:
+    conn: A connection to the parent process. The child process sends
+        the local port, and waits for a message from the parent to
+        stop serving. It also sends a "result" back to the parent -- this can
+        be used to allow a client-side test to notify the server of results.
+    dirname: The directory to serve. All files are accessible through
+       http://localhost:<port>/path/to/filename.
+    port: The port to serve on. If 0, an ephemeral port will be chosen.
+    server_kwargs: A dict that will be passed as kwargs to the server.
+  """
+  try:
+    os.chdir(dirname)
+    httpd = PluggableHTTPServer(('', port), PluggableHTTPRequestHandler,
+                                **server_kwargs)
+  except socket.error as e:
+    sys.stderr.write('Error creating HTTPServer: %s\n' % e)
+    sys.exit(1)
+
+  try:
+    conn.send(httpd.server_address[1])  # the chosen port number
+    httpd.timeout = 0.5  # seconds
+    while httpd.running:
+      # Flush output for MSVS Add-In.
+      sys.stdout.flush()
+      sys.stderr.flush()
+      httpd.handle_request()
+      if conn.poll():
+        httpd.running = conn.recv()
+  except KeyboardInterrupt:
+    pass
+  finally:
+    conn.send(httpd.result)
+    conn.close()
+
+
+def main(args):
+  parser = optparse.OptionParser()
+  parser.add_option('-C', '--serve-dir',
+      help='Serve files out of this directory.',
+      dest='serve_dir', default=os.path.abspath('.'))
+  parser.add_option('-p', '--port',
+      help='Run server on this port.',
+      dest='port', default=5103)
+  parser.add_option('--no_dir_check',
+      help='No check to ensure serving from safe directory.',
+      dest='do_safe_check', action='store_false', default=True)
+  parser.add_option('--test-mode',
+      help='Listen for posts to /ok or /fail and shut down the server with '
+          ' errorcodes 0 and 1 respectively.',
+      dest='test_mode', action='store_true')
+  options, args = parser.parse_args(args)
+  if options.do_safe_check:
+    SanityCheckDirectory(options.serve_dir)
+
+  server = LocalHTTPServer(options.serve_dir, int(options.port),
+                           options.test_mode)
+
+  # Serve until the client tells us to stop. When it does, it will give us an
+  # errorcode.
+  print 'Serving %s on %s...' % (options.serve_dir, server.GetURL(''))
+  return server.ServeForever()
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))