1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/testing/mochitest/pywebsocket/mod_pywebsocket/dispatch.py Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,381 @@
1.4 +# Copyright 2012, Google Inc.
1.5 +# All rights reserved.
1.6 +#
1.7 +# Redistribution and use in source and binary forms, with or without
1.8 +# modification, are permitted provided that the following conditions are
1.9 +# met:
1.10 +#
1.11 +# * Redistributions of source code must retain the above copyright
1.12 +# notice, this list of conditions and the following disclaimer.
1.13 +# * Redistributions in binary form must reproduce the above
1.14 +# copyright notice, this list of conditions and the following disclaimer
1.15 +# in the documentation and/or other materials provided with the
1.16 +# distribution.
1.17 +# * Neither the name of Google Inc. nor the names of its
1.18 +# contributors may be used to endorse or promote products derived from
1.19 +# this software without specific prior written permission.
1.20 +#
1.21 +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.22 +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.23 +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.24 +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
1.25 +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1.26 +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1.27 +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.28 +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.29 +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.30 +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1.31 +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.32 +
1.33 +
1.34 +"""Dispatch WebSocket request.
1.35 +"""
1.36 +
1.37 +
1.38 +import logging
1.39 +import os
1.40 +import re
1.41 +
1.42 +from mod_pywebsocket import common
1.43 +from mod_pywebsocket import handshake
1.44 +from mod_pywebsocket import msgutil
1.45 +from mod_pywebsocket import stream
1.46 +from mod_pywebsocket import util
1.47 +
1.48 +
1.49 +_SOURCE_PATH_PATTERN = re.compile(r'(?i)_wsh\.py$')
1.50 +_SOURCE_SUFFIX = '_wsh.py'
1.51 +_DO_EXTRA_HANDSHAKE_HANDLER_NAME = 'web_socket_do_extra_handshake'
1.52 +_TRANSFER_DATA_HANDLER_NAME = 'web_socket_transfer_data'
1.53 +_PASSIVE_CLOSING_HANDSHAKE_HANDLER_NAME = (
1.54 + 'web_socket_passive_closing_handshake')
1.55 +
1.56 +
1.57 +class DispatchException(Exception):
1.58 + """Exception in dispatching WebSocket request."""
1.59 +
1.60 + def __init__(self, name, status=common.HTTP_STATUS_NOT_FOUND):
1.61 + super(DispatchException, self).__init__(name)
1.62 + self.status = status
1.63 +
1.64 +
1.65 +def _default_passive_closing_handshake_handler(request):
1.66 + """Default web_socket_passive_closing_handshake handler."""
1.67 +
1.68 + return common.STATUS_NORMAL_CLOSURE, ''
1.69 +
1.70 +
1.71 +def _normalize_path(path):
1.72 + """Normalize path.
1.73 +
1.74 + Args:
1.75 + path: the path to normalize.
1.76 +
1.77 + Path is converted to the absolute path.
1.78 + The input path can use either '\\' or '/' as the separator.
1.79 + The normalized path always uses '/' regardless of the platform.
1.80 + """
1.81 +
1.82 + path = path.replace('\\', os.path.sep)
1.83 + path = os.path.realpath(path)
1.84 + path = path.replace('\\', '/')
1.85 + return path
1.86 +
1.87 +
1.88 +def _create_path_to_resource_converter(base_dir):
1.89 + """Returns a function that converts the path of a WebSocket handler source
1.90 + file to a resource string by removing the path to the base directory from
1.91 + its head, removing _SOURCE_SUFFIX from its tail, and replacing path
1.92 + separators in it with '/'.
1.93 +
1.94 + Args:
1.95 + base_dir: the path to the base directory.
1.96 + """
1.97 +
1.98 + base_dir = _normalize_path(base_dir)
1.99 +
1.100 + base_len = len(base_dir)
1.101 + suffix_len = len(_SOURCE_SUFFIX)
1.102 +
1.103 + def converter(path):
1.104 + if not path.endswith(_SOURCE_SUFFIX):
1.105 + return None
1.106 + # _normalize_path must not be used because resolving symlink breaks
1.107 + # following path check.
1.108 + path = path.replace('\\', '/')
1.109 + if not path.startswith(base_dir):
1.110 + return None
1.111 + return path[base_len:-suffix_len]
1.112 +
1.113 + return converter
1.114 +
1.115 +
1.116 +def _enumerate_handler_file_paths(directory):
1.117 + """Returns a generator that enumerates WebSocket Handler source file names
1.118 + in the given directory.
1.119 + """
1.120 +
1.121 + for root, unused_dirs, files in os.walk(directory):
1.122 + for base in files:
1.123 + path = os.path.join(root, base)
1.124 + if _SOURCE_PATH_PATTERN.search(path):
1.125 + yield path
1.126 +
1.127 +
1.128 +class _HandlerSuite(object):
1.129 + """A handler suite holder class."""
1.130 +
1.131 + def __init__(self, do_extra_handshake, transfer_data,
1.132 + passive_closing_handshake):
1.133 + self.do_extra_handshake = do_extra_handshake
1.134 + self.transfer_data = transfer_data
1.135 + self.passive_closing_handshake = passive_closing_handshake
1.136 +
1.137 +
1.138 +def _source_handler_file(handler_definition):
1.139 + """Source a handler definition string.
1.140 +
1.141 + Args:
1.142 + handler_definition: a string containing Python statements that define
1.143 + handler functions.
1.144 + """
1.145 +
1.146 + global_dic = {}
1.147 + try:
1.148 + exec handler_definition in global_dic
1.149 + except Exception:
1.150 + raise DispatchException('Error in sourcing handler:' +
1.151 + util.get_stack_trace())
1.152 + passive_closing_handshake_handler = None
1.153 + try:
1.154 + passive_closing_handshake_handler = _extract_handler(
1.155 + global_dic, _PASSIVE_CLOSING_HANDSHAKE_HANDLER_NAME)
1.156 + except Exception:
1.157 + passive_closing_handshake_handler = (
1.158 + _default_passive_closing_handshake_handler)
1.159 + return _HandlerSuite(
1.160 + _extract_handler(global_dic, _DO_EXTRA_HANDSHAKE_HANDLER_NAME),
1.161 + _extract_handler(global_dic, _TRANSFER_DATA_HANDLER_NAME),
1.162 + passive_closing_handshake_handler)
1.163 +
1.164 +
1.165 +def _extract_handler(dic, name):
1.166 + """Extracts a callable with the specified name from the given dictionary
1.167 + dic.
1.168 + """
1.169 +
1.170 + if name not in dic:
1.171 + raise DispatchException('%s is not defined.' % name)
1.172 + handler = dic[name]
1.173 + if not callable(handler):
1.174 + raise DispatchException('%s is not callable.' % name)
1.175 + return handler
1.176 +
1.177 +
1.178 +class Dispatcher(object):
1.179 + """Dispatches WebSocket requests.
1.180 +
1.181 + This class maintains a map from resource name to handlers.
1.182 + """
1.183 +
1.184 + def __init__(
1.185 + self, root_dir, scan_dir=None,
1.186 + allow_handlers_outside_root_dir=True):
1.187 + """Construct an instance.
1.188 +
1.189 + Args:
1.190 + root_dir: The directory where handler definition files are
1.191 + placed.
1.192 + scan_dir: The directory where handler definition files are
1.193 + searched. scan_dir must be a directory under root_dir,
1.194 + including root_dir itself. If scan_dir is None,
1.195 + root_dir is used as scan_dir. scan_dir can be useful
1.196 + in saving scan time when root_dir contains many
1.197 + subdirectories.
1.198 + allow_handlers_outside_root_dir: Scans handler files even if their
1.199 + canonical path is not under root_dir.
1.200 + """
1.201 +
1.202 + self._logger = util.get_class_logger(self)
1.203 +
1.204 + self._handler_suite_map = {}
1.205 + self._source_warnings = []
1.206 + if scan_dir is None:
1.207 + scan_dir = root_dir
1.208 + if not os.path.realpath(scan_dir).startswith(
1.209 + os.path.realpath(root_dir)):
1.210 + raise DispatchException('scan_dir:%s must be a directory under '
1.211 + 'root_dir:%s.' % (scan_dir, root_dir))
1.212 + self._source_handler_files_in_dir(
1.213 + root_dir, scan_dir, allow_handlers_outside_root_dir)
1.214 +
1.215 + def add_resource_path_alias(self,
1.216 + alias_resource_path, existing_resource_path):
1.217 + """Add resource path alias.
1.218 +
1.219 + Once added, request to alias_resource_path would be handled by
1.220 + handler registered for existing_resource_path.
1.221 +
1.222 + Args:
1.223 + alias_resource_path: alias resource path
1.224 + existing_resource_path: existing resource path
1.225 + """
1.226 + try:
1.227 + handler_suite = self._handler_suite_map[existing_resource_path]
1.228 + self._handler_suite_map[alias_resource_path] = handler_suite
1.229 + except KeyError:
1.230 + raise DispatchException('No handler for: %r' %
1.231 + existing_resource_path)
1.232 +
1.233 + def source_warnings(self):
1.234 + """Return warnings in sourcing handlers."""
1.235 +
1.236 + return self._source_warnings
1.237 +
1.238 + def do_extra_handshake(self, request):
1.239 + """Do extra checking in WebSocket handshake.
1.240 +
1.241 + Select a handler based on request.uri and call its
1.242 + web_socket_do_extra_handshake function.
1.243 +
1.244 + Args:
1.245 + request: mod_python request.
1.246 +
1.247 + Raises:
1.248 + DispatchException: when handler was not found
1.249 + AbortedByUserException: when user handler abort connection
1.250 + HandshakeException: when opening handshake failed
1.251 + """
1.252 +
1.253 + handler_suite = self.get_handler_suite(request.ws_resource)
1.254 + if handler_suite is None:
1.255 + raise DispatchException('No handler for: %r' % request.ws_resource)
1.256 + do_extra_handshake_ = handler_suite.do_extra_handshake
1.257 + try:
1.258 + do_extra_handshake_(request)
1.259 + except handshake.AbortedByUserException, e:
1.260 + raise
1.261 + except Exception, e:
1.262 + util.prepend_message_to_exception(
1.263 + '%s raised exception for %s: ' % (
1.264 + _DO_EXTRA_HANDSHAKE_HANDLER_NAME,
1.265 + request.ws_resource),
1.266 + e)
1.267 + raise handshake.HandshakeException(e, common.HTTP_STATUS_FORBIDDEN)
1.268 +
1.269 + def transfer_data(self, request):
1.270 + """Let a handler transfer_data with a WebSocket client.
1.271 +
1.272 + Select a handler based on request.ws_resource and call its
1.273 + web_socket_transfer_data function.
1.274 +
1.275 + Args:
1.276 + request: mod_python request.
1.277 +
1.278 + Raises:
1.279 + DispatchException: when handler was not found
1.280 + AbortedByUserException: when user handler abort connection
1.281 + """
1.282 +
1.283 + handler_suite = self.get_handler_suite(request.ws_resource)
1.284 + if handler_suite is None:
1.285 + raise DispatchException('No handler for: %r' % request.ws_resource)
1.286 + transfer_data_ = handler_suite.transfer_data
1.287 + # TODO(tyoshino): Terminate underlying TCP connection if possible.
1.288 + try:
1.289 + transfer_data_(request)
1.290 + if not request.server_terminated:
1.291 + request.ws_stream.close_connection()
1.292 + # Catch non-critical exceptions the handler didn't handle.
1.293 + except handshake.AbortedByUserException, e:
1.294 + self._logger.debug('%s', e)
1.295 + raise
1.296 + except msgutil.BadOperationException, e:
1.297 + self._logger.debug('%s', e)
1.298 + request.ws_stream.close_connection(common.STATUS_ABNORMAL_CLOSURE)
1.299 + except msgutil.InvalidFrameException, e:
1.300 + # InvalidFrameException must be caught before
1.301 + # ConnectionTerminatedException that catches InvalidFrameException.
1.302 + self._logger.debug('%s', e)
1.303 + request.ws_stream.close_connection(common.STATUS_PROTOCOL_ERROR)
1.304 + except msgutil.UnsupportedFrameException, e:
1.305 + self._logger.debug('%s', e)
1.306 + request.ws_stream.close_connection(common.STATUS_UNSUPPORTED_DATA)
1.307 + except stream.InvalidUTF8Exception, e:
1.308 + self._logger.debug('%s', e)
1.309 + request.ws_stream.close_connection(
1.310 + common.STATUS_INVALID_FRAME_PAYLOAD_DATA)
1.311 + except msgutil.ConnectionTerminatedException, e:
1.312 + self._logger.debug('%s', e)
1.313 + except Exception, e:
1.314 + util.prepend_message_to_exception(
1.315 + '%s raised exception for %s: ' % (
1.316 + _TRANSFER_DATA_HANDLER_NAME, request.ws_resource),
1.317 + e)
1.318 + raise
1.319 +
1.320 + def passive_closing_handshake(self, request):
1.321 + """Prepare code and reason for responding client initiated closing
1.322 + handshake.
1.323 + """
1.324 +
1.325 + handler_suite = self.get_handler_suite(request.ws_resource)
1.326 + if handler_suite is None:
1.327 + return _default_passive_closing_handshake_handler(request)
1.328 + return handler_suite.passive_closing_handshake(request)
1.329 +
1.330 + def get_handler_suite(self, resource):
1.331 + """Retrieves two handlers (one for extra handshake processing, and one
1.332 + for data transfer) for the given request as a HandlerSuite object.
1.333 + """
1.334 +
1.335 + fragment = None
1.336 + if '#' in resource:
1.337 + resource, fragment = resource.split('#', 1)
1.338 + if '?' in resource:
1.339 + resource = resource.split('?', 1)[0]
1.340 + handler_suite = self._handler_suite_map.get(resource)
1.341 + if handler_suite and fragment:
1.342 + raise DispatchException('Fragment identifiers MUST NOT be used on '
1.343 + 'WebSocket URIs',
1.344 + common.HTTP_STATUS_BAD_REQUEST)
1.345 + return handler_suite
1.346 +
1.347 + def _source_handler_files_in_dir(
1.348 + self, root_dir, scan_dir, allow_handlers_outside_root_dir):
1.349 + """Source all the handler source files in the scan_dir directory.
1.350 +
1.351 + The resource path is determined relative to root_dir.
1.352 + """
1.353 +
1.354 + # We build a map from resource to handler code assuming that there's
1.355 + # only one path from root_dir to scan_dir and it can be obtained by
1.356 + # comparing realpath of them.
1.357 +
1.358 + # Here we cannot use abspath. See
1.359 + # https://bugs.webkit.org/show_bug.cgi?id=31603
1.360 +
1.361 + convert = _create_path_to_resource_converter(root_dir)
1.362 + scan_realpath = os.path.realpath(scan_dir)
1.363 + root_realpath = os.path.realpath(root_dir)
1.364 + for path in _enumerate_handler_file_paths(scan_realpath):
1.365 + if (not allow_handlers_outside_root_dir and
1.366 + (not os.path.realpath(path).startswith(root_realpath))):
1.367 + self._logger.debug(
1.368 + 'Canonical path of %s is not under root directory' %
1.369 + path)
1.370 + continue
1.371 + try:
1.372 + handler_suite = _source_handler_file(open(path).read())
1.373 + except DispatchException, e:
1.374 + self._source_warnings.append('%s: %s' % (path, e))
1.375 + continue
1.376 + resource = convert(path)
1.377 + if resource is None:
1.378 + self._logger.debug(
1.379 + 'Path to resource conversion on %s failed' % path)
1.380 + else:
1.381 + self._handler_suite_map[convert(path)] = handler_suite
1.382 +
1.383 +
1.384 +# vi:sts=4 sw=4 et
