michael@0: # Copyright 2011, Google Inc.
michael@0: # All rights reserved.
michael@0: #
michael@0: # Redistribution and use in source and binary forms, with or without
michael@0: # modification, are permitted provided that the following conditions are
michael@0: # met:
michael@0: #
michael@0: #     * Redistributions of source code must retain the above copyright
michael@0: # notice, this list of conditions and the following disclaimer.
michael@0: #     * Redistributions in binary form must reproduce the above
michael@0: # copyright notice, this list of conditions and the following disclaimer
michael@0: # in the documentation and/or other materials provided with the
michael@0: # distribution.
michael@0: #     * Neither the name of Google Inc. nor the names of its
michael@0: # contributors may be used to endorse or promote products derived from
michael@0: # this software without specific prior written permission.
michael@0: #
michael@0: # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
michael@0: # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
michael@0: # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: 
michael@0: """PythonHeaderParserHandler for mod_pywebsocket.
michael@0: 
michael@0: Apache HTTP Server and mod_python must be configured such that this
michael@0: function is called to handle WebSocket request.
michael@0: """
michael@0: 
michael@0: 
michael@0: import logging
michael@0: 
michael@0: from mod_python import apache
michael@0: 
michael@0: from mod_pywebsocket import common
michael@0: from mod_pywebsocket import dispatch
michael@0: from mod_pywebsocket import handshake
michael@0: from mod_pywebsocket import util
michael@0: 
michael@0: 
michael@0: # PythonOption to specify the handler root directory.
michael@0: _PYOPT_HANDLER_ROOT = 'mod_pywebsocket.handler_root'
michael@0: 
michael@0: # PythonOption to specify the handler scan directory.
michael@0: # This must be a directory under the root directory.
michael@0: # The default is the root directory.
michael@0: _PYOPT_HANDLER_SCAN = 'mod_pywebsocket.handler_scan'
michael@0: 
michael@0: # PythonOption to allow handlers whose canonical path is
michael@0: # not under the root directory. It's disallowed by default.
michael@0: # Set this option with value of 'yes' to allow.
michael@0: _PYOPT_ALLOW_HANDLERS_OUTSIDE_ROOT = (
michael@0:     'mod_pywebsocket.allow_handlers_outside_root_dir')
michael@0: # Map from values to their meanings. 'Yes' and 'No' are allowed just for
michael@0: # compatibility.
michael@0: _PYOPT_ALLOW_HANDLERS_OUTSIDE_ROOT_DEFINITION = {
michael@0:     'off': False, 'no': False, 'on': True, 'yes': True}
michael@0: 
michael@0: # PythonOption to specify to allow draft75 handshake.
michael@0: # The default is None (Off)
michael@0: _PYOPT_ALLOW_DRAFT75 = 'mod_pywebsocket.allow_draft75'
michael@0: # Map from values to their meanings.
michael@0: _PYOPT_ALLOW_DRAFT75_DEFINITION = {'off': False, 'on': True}
michael@0: 
michael@0: 
michael@0: class ApacheLogHandler(logging.Handler):
michael@0:     """Wrapper logging.Handler to emit log message to apache's error.log."""
michael@0: 
michael@0:     _LEVELS = {
michael@0:         logging.DEBUG: apache.APLOG_DEBUG,
michael@0:         logging.INFO: apache.APLOG_INFO,
michael@0:         logging.WARNING: apache.APLOG_WARNING,
michael@0:         logging.ERROR: apache.APLOG_ERR,
michael@0:         logging.CRITICAL: apache.APLOG_CRIT,
michael@0:         }
michael@0: 
michael@0:     def __init__(self, request=None):
michael@0:         logging.Handler.__init__(self)
michael@0:         self._log_error = apache.log_error
michael@0:         if request is not None:
michael@0:             self._log_error = request.log_error
michael@0: 
michael@0:         # Time and level will be printed by Apache.
michael@0:         self._formatter = logging.Formatter('%(name)s: %(message)s')
michael@0: 
michael@0:     def emit(self, record):
michael@0:         apache_level = apache.APLOG_DEBUG
michael@0:         if record.levelno in ApacheLogHandler._LEVELS:
michael@0:             apache_level = ApacheLogHandler._LEVELS[record.levelno]
michael@0: 
michael@0:         msg = self._formatter.format(record)
michael@0: 
michael@0:         # "server" parameter must be passed to have "level" parameter work.
michael@0:         # If only "level" parameter is passed, nothing shows up on Apache's
michael@0:         # log. However, at this point, we cannot get the server object of the
michael@0:         # virtual host which will process WebSocket requests. The only server
michael@0:         # object we can get here is apache.main_server. But Wherever (server
michael@0:         # configuration context or virtual host context) we put
michael@0:         # PythonHeaderParserHandler directive, apache.main_server just points
michael@0:         # the main server instance (not any of virtual server instance). Then,
michael@0:         # Apache follows LogLevel directive in the server configuration context
michael@0:         # to filter logs. So, we need to specify LogLevel in the server
michael@0:         # configuration context. Even if we specify "LogLevel debug" in the
michael@0:         # virtual host context which actually handles WebSocket connections,
michael@0:         # DEBUG level logs never show up unless "LogLevel debug" is specified
michael@0:         # in the server configuration context.
michael@0:         #
michael@0:         # TODO(tyoshino): Provide logging methods on request object. When
michael@0:         # request is mp_request object (when used together with Apache), the
michael@0:         # methods call request.log_error indirectly. When request is
michael@0:         # _StandaloneRequest, the methods call Python's logging facility which
michael@0:         # we create in standalone.py.
michael@0:         self._log_error(msg, apache_level, apache.main_server)
michael@0: 
michael@0: 
michael@0: def _configure_logging():
michael@0:     logger = logging.getLogger()
michael@0:     # Logs are filtered by Apache based on LogLevel directive in Apache
michael@0:     # configuration file. We must just pass logs for all levels to
michael@0:     # ApacheLogHandler.
michael@0:     logger.setLevel(logging.DEBUG)
michael@0:     logger.addHandler(ApacheLogHandler())
michael@0: 
michael@0: 
michael@0: _configure_logging()
michael@0: 
michael@0: _LOGGER = logging.getLogger(__name__)
michael@0: 
michael@0: 
michael@0: def _parse_option(name, value, definition):
michael@0:     if value is None:
michael@0:         return False
michael@0: 
michael@0:     meaning = definition.get(value.lower())
michael@0:     if meaning is None:
michael@0:         raise Exception('Invalid value for PythonOption %s: %r' %
michael@0:                         (name, value))
michael@0:     return meaning
michael@0: 
michael@0: 
michael@0: def _create_dispatcher():
michael@0:     _LOGGER.info('Initializing Dispatcher')
michael@0: 
michael@0:     options = apache.main_server.get_options()
michael@0: 
michael@0:     handler_root = options.get(_PYOPT_HANDLER_ROOT, None)
michael@0:     if not handler_root:
michael@0:         raise Exception('PythonOption %s is not defined' % _PYOPT_HANDLER_ROOT,
michael@0:                         apache.APLOG_ERR)
michael@0: 
michael@0:     handler_scan = options.get(_PYOPT_HANDLER_SCAN, handler_root)
michael@0: 
michael@0:     allow_handlers_outside_root = _parse_option(
michael@0:         _PYOPT_ALLOW_HANDLERS_OUTSIDE_ROOT,
michael@0:         options.get(_PYOPT_ALLOW_HANDLERS_OUTSIDE_ROOT),
michael@0:         _PYOPT_ALLOW_HANDLERS_OUTSIDE_ROOT_DEFINITION)
michael@0: 
michael@0:     dispatcher = dispatch.Dispatcher(
michael@0:         handler_root, handler_scan, allow_handlers_outside_root)
michael@0: 
michael@0:     for warning in dispatcher.source_warnings():
michael@0:         apache.log_error('mod_pywebsocket: %s' % warning, apache.APLOG_WARNING)
michael@0: 
michael@0:     return dispatcher
michael@0: 
michael@0: 
michael@0: # Initialize
michael@0: _dispatcher = _create_dispatcher()
michael@0: 
michael@0: 
michael@0: def headerparserhandler(request):
michael@0:     """Handle request.
michael@0: 
michael@0:     Args:
michael@0:         request: mod_python request.
michael@0: 
michael@0:     This function is named headerparserhandler because it is the default
michael@0:     name for a PythonHeaderParserHandler.
michael@0:     """
michael@0: 
michael@0:     handshake_is_done = False
michael@0:     try:
michael@0:         # Fallback to default http handler for request paths for which
michael@0:         # we don't have request handlers.
michael@0:         if not _dispatcher.get_handler_suite(request.uri):
michael@0:             request.log_error('No handler for resource: %r' % request.uri,
michael@0:                               apache.APLOG_INFO)
michael@0:             request.log_error('Fallback to Apache', apache.APLOG_INFO)
michael@0:             return apache.DECLINED
michael@0:     except dispatch.DispatchException, e:
michael@0:         request.log_error('mod_pywebsocket: %s' % e, apache.APLOG_INFO)
michael@0:         if not handshake_is_done:
michael@0:             return e.status
michael@0: 
michael@0:     try:
michael@0:         allow_draft75 = _parse_option(
michael@0:             _PYOPT_ALLOW_DRAFT75,
michael@0:             apache.main_server.get_options().get(_PYOPT_ALLOW_DRAFT75),
michael@0:             _PYOPT_ALLOW_DRAFT75_DEFINITION)
michael@0: 
michael@0:         try:
michael@0:             handshake.do_handshake(
michael@0:                 request, _dispatcher, allowDraft75=allow_draft75)
michael@0:         except handshake.VersionException, e:
michael@0:             request.log_error('mod_pywebsocket: %s' % e, apache.APLOG_INFO)
michael@0:             request.err_headers_out.add(common.SEC_WEBSOCKET_VERSION_HEADER,
michael@0:                                         e.supported_versions)
michael@0:             return apache.HTTP_BAD_REQUEST
michael@0:         except handshake.HandshakeException, e:
michael@0:             # Handshake for ws/wss failed.
michael@0:             # Send http response with error status.
michael@0:             request.log_error('mod_pywebsocket: %s' % e, apache.APLOG_INFO)
michael@0:             return e.status
michael@0: 
michael@0:         handshake_is_done = True
michael@0:         request._dispatcher = _dispatcher
michael@0:         _dispatcher.transfer_data(request)
michael@0:     except handshake.AbortedByUserException, e:
michael@0:         request.log_error('mod_pywebsocket: %s' % e, apache.APLOG_INFO)
michael@0:     except Exception, e:
michael@0:         # DispatchException can also be thrown if something is wrong in
michael@0:         # pywebsocket code. It's caught here, then.
michael@0: 
michael@0:         request.log_error('mod_pywebsocket: %s\n%s' %
michael@0:                           (e, util.get_stack_trace()),
michael@0:                           apache.APLOG_ERR)
michael@0:         # Unknown exceptions before handshake mean Apache must handle its
michael@0:         # request with another handler.
michael@0:         if not handshake_is_done:
michael@0:             return apache.DECLINED
michael@0:     # Set assbackwards to suppress response header generation by Apache.
michael@0:     request.assbackwards = 1
michael@0:     return apache.DONE  # Return DONE such that no other handlers are invoked.
michael@0: 
michael@0: 
michael@0: # vi:sts=4 sw=4 et