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: """WebSocket opening handshake processor. This class try to apply available
michael@0: opening handshake processors for each protocol version until a connection is
michael@0: successfully established.
michael@0: """
michael@0: 
michael@0: 
michael@0: import logging
michael@0: 
michael@0: from mod_pywebsocket import common
michael@0: from mod_pywebsocket.handshake import draft75
michael@0: from mod_pywebsocket.handshake import hybi00
michael@0: from mod_pywebsocket.handshake import hybi
michael@0: # Export AbortedByUserException, HandshakeException, and VersionException
michael@0: # symbol from this module.
michael@0: from mod_pywebsocket.handshake._base import AbortedByUserException
michael@0: from mod_pywebsocket.handshake._base import HandshakeException
michael@0: from mod_pywebsocket.handshake._base import VersionException
michael@0: 
michael@0: 
michael@0: _LOGGER = logging.getLogger(__name__)
michael@0: 
michael@0: 
michael@0: def do_handshake(request, dispatcher, allowDraft75=False, strict=False):
michael@0:     """Performs WebSocket handshake.
michael@0: 
michael@0:     Args:
michael@0:         request: mod_python request.
michael@0:         dispatcher: Dispatcher (dispatch.Dispatcher).
michael@0:         allowDraft75: allow draft 75 handshake protocol.
michael@0:         strict: Strictly check handshake request in draft 75.
michael@0:             Default: False. If True, request.connection must provide
michael@0:             get_memorized_lines method.
michael@0: 
michael@0:     Handshaker will add attributes such as ws_resource in performing
michael@0:     handshake.
michael@0:     """
michael@0: 
michael@0:     _LOGGER.debug('Client\'s opening handshake resource: %r', request.uri)
michael@0:     # To print mimetools.Message as escaped one-line string, we converts
michael@0:     # headers_in to dict object. Without conversion, if we use %r, it just
michael@0:     # prints the type and address, and if we use %s, it prints the original
michael@0:     # header string as multiple lines.
michael@0:     #
michael@0:     # Both mimetools.Message and MpTable_Type of mod_python can be
michael@0:     # converted to dict.
michael@0:     #
michael@0:     # mimetools.Message.__str__ returns the original header string.
michael@0:     # dict(mimetools.Message object) returns the map from header names to
michael@0:     # header values. While MpTable_Type doesn't have such __str__ but just
michael@0:     # __repr__ which formats itself as well as dictionary object.
michael@0:     _LOGGER.debug(
michael@0:         'Client\'s opening handshake headers: %r', dict(request.headers_in))
michael@0: 
michael@0:     handshakers = []
michael@0:     handshakers.append(
michael@0:         ('RFC 6455', hybi.Handshaker(request, dispatcher)))
michael@0:     handshakers.append(
michael@0:         ('HyBi 00', hybi00.Handshaker(request, dispatcher)))
michael@0:     if allowDraft75:
michael@0:         handshakers.append(
michael@0:             ('Hixie 75', draft75.Handshaker(request, dispatcher, strict)))
michael@0: 
michael@0:     for name, handshaker in handshakers:
michael@0:         _LOGGER.debug('Trying protocol version %s', name)
michael@0:         try:
michael@0:             handshaker.do_handshake()
michael@0:             _LOGGER.info('Established (%s protocol)', name)
michael@0:             return
michael@0:         except HandshakeException, e:
michael@0:             _LOGGER.debug(
michael@0:                 'Failed to complete opening handshake as %s protocol: %r',
michael@0:                 name, e)
michael@0:             if e.status:
michael@0:                 raise e
michael@0:         except AbortedByUserException, e:
michael@0:             raise
michael@0:         except VersionException, e:
michael@0:             raise
michael@0: 
michael@0:     # TODO(toyoshim): Add a test to cover the case all handshakers fail.
michael@0:     raise HandshakeException(
michael@0:         'Failed to complete opening handshake for all available protocols',
michael@0:         status=common.HTTP_STATUS_BAD_REQUEST)
michael@0: 
michael@0: 
michael@0: # vi:sts=4 sw=4 et