The Tor Browser: testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py@b8a032363ba2 (annotated)

testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py@b8a032363ba2 (annotated)

testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 # Copyright 2012, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
 # in the documentation and/or other materials provided with the
 # distribution.
 #     * Neither the name of Google Inc. nor the names of its
 # contributors may be used to endorse or promote products derived from
 # this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 """Dispatch WebSocket request.
 """
 import logging
 import os
 import re
 from mod_pywebsocket import common
 from mod_pywebsocket import handshake
 from mod_pywebsocket import msgutil
 from mod_pywebsocket import stream
 from mod_pywebsocket import util
 _SOURCE_PATH_PATTERN = re.compile(r'(?i)_wsh\.py$')
 _SOURCE_SUFFIX = '_wsh.py'
 _DO_EXTRA_HANDSHAKE_HANDLER_NAME = 'web_socket_do_extra_handshake'
 _TRANSFER_DATA_HANDLER_NAME = 'web_socket_transfer_data'
 _PASSIVE_CLOSING_HANDSHAKE_HANDLER_NAME = (
     'web_socket_passive_closing_handshake')
 class DispatchException(Exception):
     """Exception in dispatching WebSocket request."""
     def __init__(self, name, status=common.HTTP_STATUS_NOT_FOUND):
         super(DispatchException, self).__init__(name)
         self.status = status
 def _default_passive_closing_handshake_handler(request):
     """Default web_socket_passive_closing_handshake handler."""
     return common.STATUS_NORMAL_CLOSURE, ''
 def _normalize_path(path):
     """Normalize path.
     Args:
         path: the path to normalize.
     Path is converted to the absolute path.
     The input path can use either '\\' or '/' as the separator.
     The normalized path always uses '/' regardless of the platform.
     """
     path = path.replace('\\', os.path.sep)
     path = os.path.realpath(path)
     path = path.replace('\\', '/')
     return path
 def _create_path_to_resource_converter(base_dir):
     """Returns a function that converts the path of a WebSocket handler source
     file to a resource string by removing the path to the base directory from
     its head, removing _SOURCE_SUFFIX from its tail, and replacing path
     separators in it with '/'.
     Args:
         base_dir: the path to the base directory.
     """
     base_dir = _normalize_path(base_dir)
     base_len = len(base_dir)
     suffix_len = len(_SOURCE_SUFFIX)
     def converter(path):
         if not path.endswith(_SOURCE_SUFFIX):
             return None
         # _normalize_path must not be used because resolving symlink breaks
         # following path check.
         path = path.replace('\\', '/')
         if not path.startswith(base_dir):
             return None
         return path[base_len:-suffix_len]
     return converter
 def _enumerate_handler_file_paths(directory):
     """Returns a generator that enumerates WebSocket Handler source file names
     in the given directory.
     """
     for root, unused_dirs, files in os.walk(directory):
         for base in files:
             path = os.path.join(root, base)
             if _SOURCE_PATH_PATTERN.search(path):
                 yield path
 class _HandlerSuite(object):
     """A handler suite holder class."""
     def __init__(self, do_extra_handshake, transfer_data,
                  passive_closing_handshake):
         self.do_extra_handshake = do_extra_handshake
         self.transfer_data = transfer_data
         self.passive_closing_handshake = passive_closing_handshake
 def _source_handler_file(handler_definition):
     """Source a handler definition string.
     Args:
         handler_definition: a string containing Python statements that define
                             handler functions.
     """
     global_dic = {}
     try:
         exec handler_definition in global_dic
     except Exception:
         raise DispatchException('Error in sourcing handler:' +
                                 util.get_stack_trace())
     passive_closing_handshake_handler = None
     try:
         passive_closing_handshake_handler = _extract_handler(
             global_dic, _PASSIVE_CLOSING_HANDSHAKE_HANDLER_NAME)
     except Exception:
         passive_closing_handshake_handler = (
             _default_passive_closing_handshake_handler)
     return _HandlerSuite(
         _extract_handler(global_dic, _DO_EXTRA_HANDSHAKE_HANDLER_NAME),
         _extract_handler(global_dic, _TRANSFER_DATA_HANDLER_NAME),
         passive_closing_handshake_handler)
 def _extract_handler(dic, name):
     """Extracts a callable with the specified name from the given dictionary
     dic.
     """
     if name not in dic:
         raise DispatchException('%s is not defined.' % name)
     handler = dic[name]
     if not callable(handler):
         raise DispatchException('%s is not callable.' % name)
     return handler
 class Dispatcher(object):
     """Dispatches WebSocket requests.
     This class maintains a map from resource name to handlers.
     """
     def __init__(
         self, root_dir, scan_dir=None,
         allow_handlers_outside_root_dir=True):
         """Construct an instance.
         Args:
             root_dir: The directory where handler definition files are
                       placed.
             scan_dir: The directory where handler definition files are
                       searched. scan_dir must be a directory under root_dir,
                       including root_dir itself.  If scan_dir is None,
                       root_dir is used as scan_dir. scan_dir can be useful
                       in saving scan time when root_dir contains many
                       subdirectories.
             allow_handlers_outside_root_dir: Scans handler files even if their
                       canonical path is not under root_dir.
         """
         self._logger = util.get_class_logger(self)
         self._handler_suite_map = {}
         self._source_warnings = []
         if scan_dir is None:
             scan_dir = root_dir
         if not os.path.realpath(scan_dir).startswith(
                 os.path.realpath(root_dir)):
             raise DispatchException('scan_dir:%s must be a directory under '
                                     'root_dir:%s.' % (scan_dir, root_dir))
         self._source_handler_files_in_dir(
             root_dir, scan_dir, allow_handlers_outside_root_dir)
     def add_resource_path_alias(self,
                                 alias_resource_path, existing_resource_path):
         """Add resource path alias.
         Once added, request to alias_resource_path would be handled by
         handler registered for existing_resource_path.
         Args:
             alias_resource_path: alias resource path
             existing_resource_path: existing resource path
         """
         try:
             handler_suite = self._handler_suite_map[existing_resource_path]
             self._handler_suite_map[alias_resource_path] = handler_suite
         except KeyError:
             raise DispatchException('No handler for: %r' %
                                     existing_resource_path)
     def source_warnings(self):
         """Return warnings in sourcing handlers."""
         return self._source_warnings
     def do_extra_handshake(self, request):
         """Do extra checking in WebSocket handshake.
         Select a handler based on request.uri and call its
         web_socket_do_extra_handshake function.
         Args:
             request: mod_python request.
         Raises:
             DispatchException: when handler was not found
             AbortedByUserException: when user handler abort connection
             HandshakeException: when opening handshake failed
         """
         handler_suite = self.get_handler_suite(request.ws_resource)
         if handler_suite is None:
             raise DispatchException('No handler for: %r' % request.ws_resource)
         do_extra_handshake_ = handler_suite.do_extra_handshake
         try:
             do_extra_handshake_(request)
         except handshake.AbortedByUserException, e:
             raise
         except Exception, e:
             util.prepend_message_to_exception(
                     '%s raised exception for %s: ' % (
                             _DO_EXTRA_HANDSHAKE_HANDLER_NAME,
                             request.ws_resource),
                     e)
             raise handshake.HandshakeException(e, common.HTTP_STATUS_FORBIDDEN)
     def transfer_data(self, request):
         """Let a handler transfer_data with a WebSocket client.
         Select a handler based on request.ws_resource and call its
         web_socket_transfer_data function.
         Args:
             request: mod_python request.
         Raises:
             DispatchException: when handler was not found
             AbortedByUserException: when user handler abort connection
         """
         handler_suite = self.get_handler_suite(request.ws_resource)
         if handler_suite is None:
             raise DispatchException('No handler for: %r' % request.ws_resource)
         transfer_data_ = handler_suite.transfer_data
         # TODO(tyoshino): Terminate underlying TCP connection if possible.
         try:
             transfer_data_(request)
             if not request.server_terminated:
                 request.ws_stream.close_connection()
         # Catch non-critical exceptions the handler didn't handle.
         except handshake.AbortedByUserException, e:
             self._logger.debug('%s', e)
             raise
         except msgutil.BadOperationException, e:
             self._logger.debug('%s', e)
             request.ws_stream.close_connection(common.STATUS_ABNORMAL_CLOSURE)
         except msgutil.InvalidFrameException, e:
             # InvalidFrameException must be caught before
             # ConnectionTerminatedException that catches InvalidFrameException.
             self._logger.debug('%s', e)
             request.ws_stream.close_connection(common.STATUS_PROTOCOL_ERROR)
         except msgutil.UnsupportedFrameException, e:
             self._logger.debug('%s', e)
             request.ws_stream.close_connection(common.STATUS_UNSUPPORTED_DATA)
         except stream.InvalidUTF8Exception, e:
             self._logger.debug('%s', e)
             request.ws_stream.close_connection(
                 common.STATUS_INVALID_FRAME_PAYLOAD_DATA)
         except msgutil.ConnectionTerminatedException, e:
             self._logger.debug('%s', e)
         except Exception, e:
             util.prepend_message_to_exception(
                 '%s raised exception for %s: ' % (
                     _TRANSFER_DATA_HANDLER_NAME, request.ws_resource),
                 e)
             raise
     def passive_closing_handshake(self, request):
         """Prepare code and reason for responding client initiated closing
         handshake.
         """
         handler_suite = self.get_handler_suite(request.ws_resource)
         if handler_suite is None:
             return _default_passive_closing_handshake_handler(request)
         return handler_suite.passive_closing_handshake(request)
     def get_handler_suite(self, resource):
         """Retrieves two handlers (one for extra handshake processing, and one
         for data transfer) for the given request as a HandlerSuite object.
         """
         fragment = None
         if '#' in resource:
             resource, fragment = resource.split('#', 1)
         if '?' in resource:
             resource = resource.split('?', 1)[0]
         handler_suite = self._handler_suite_map.get(resource)
         if handler_suite and fragment:
             raise DispatchException('Fragment identifiers MUST NOT be used on '
                                     'WebSocket URIs',
                                     common.HTTP_STATUS_BAD_REQUEST)
         return handler_suite
     def _source_handler_files_in_dir(
         self, root_dir, scan_dir, allow_handlers_outside_root_dir):
         """Source all the handler source files in the scan_dir directory.
         The resource path is determined relative to root_dir.
         """
         # We build a map from resource to handler code assuming that there's
         # only one path from root_dir to scan_dir and it can be obtained by
         # comparing realpath of them.
         # Here we cannot use abspath. See
         # https://bugs.webkit.org/show_bug.cgi?id=31603
         convert = _create_path_to_resource_converter(root_dir)
         scan_realpath = os.path.realpath(scan_dir)
         root_realpath = os.path.realpath(root_dir)
         for path in _enumerate_handler_file_paths(scan_realpath):
             if (not allow_handlers_outside_root_dir and
                 (not os.path.realpath(path).startswith(root_realpath))):
                 self._logger.debug(
                     'Canonical path of %s is not under root directory' %
                     path)
                 continue
             try:
                 handler_suite = _source_handler_file(open(path).read())
             except DispatchException, e:
                 self._source_warnings.append('%s: %s' % (path, e))
                 continue
             resource = convert(path)
             if resource is None:
                 self._logger.debug(
                     'Path to resource conversion on %s failed' % path)
             else:
                 self._handler_suite_map[convert(path)] = handler_suite
 # vi:sts=4 sw=4 et

The Tor Browser / annotate

testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py@b8a032363ba2 (annotated)

testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py