| # Copyright 2013, 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. |
| |
| from six.moves.urllib import parse |
| import zlib |
| from mod_pywebsocket import common |
| from mod_pywebsocket import util |
| from mod_pywebsocket.extensions import PerMessageDeflateExtensionProcessor |
| from mod_pywebsocket.extensions import ExtensionProcessorInterface |
| from mod_pywebsocket.common import ExtensionParameter |
| |
| _GOODBYE_MESSAGE = u'Goodbye' |
| _ENABLE_MESSAGE = u'EnableCompression' |
| _DISABLE_MESSAGE = u'DisableCompression' |
| _bfinal = False |
| _client_max_window_bits = 15 |
| |
| |
| def _get_permessage_deflate_extension_processor(request): |
| for extension_processor in request.ws_extension_processors: |
| if isinstance(extension_processor, PerMessageDeflateExtensionProcessor): |
| return extension_processor |
| return None |
| |
| |
| def web_socket_do_extra_handshake(request): |
| global _bfinal |
| global _client_max_window_bits |
| processor = _get_permessage_deflate_extension_processor(request) |
| # Remove extension processors other than |
| # PerMessageDeflateExtensionProcessor to avoid conflict. |
| request.ws_extension_processors = [processor] |
| if not processor: |
| return |
| r = request.ws_resource.split('?', 1) |
| if len(r) == 1: |
| return |
| parameters = parse.parse_qs(r[1], keep_blank_values=True) |
| if 'client_max_window_bits' in parameters: |
| window_bits = int(parameters['client_max_window_bits'][0]) |
| processor.set_client_max_window_bits(window_bits) |
| _client_max_window_bits = window_bits |
| if 'client_no_context_takeover' in parameters: |
| processor.set_client_no_context_takeover(True) |
| if 'set_bfinal' in parameters: |
| _bfinal = True |
| |
| |
| def receive(request): |
| stream = request.ws_stream |
| possibly_compressed_body = b'' |
| compress = False |
| while True: |
| frame = stream._receive_frame_as_frame_object() |
| if frame.opcode == common.OPCODE_CLOSE: |
| message = stream._get_message_from_frame(frame) |
| stream._process_close_message(message) |
| return (False, None) |
| compress = compress or frame.rsv1 |
| possibly_compressed_body += frame.payload |
| if frame.fin: |
| break |
| if compress: |
| return (compress, possibly_compressed_body + b'\x00\x00\xff\xff') |
| else: |
| return (compress, possibly_compressed_body) |
| |
| |
| def web_socket_transfer_data(request): |
| processor = _get_permessage_deflate_extension_processor(request) |
| processor.set_bfinal(_bfinal) |
| inflater = util._Inflater(_client_max_window_bits) |
| while True: |
| compress, possibly_compressed_body = receive(request) |
| body = None |
| if possibly_compressed_body is None: |
| return |
| if compress: |
| inflater.append(possibly_compressed_body) |
| body = inflater.decompress(-1) |
| else: |
| body = possibly_compressed_body |
| |
| text = body.decode('utf-8') |
| if processor: |
| if text == _ENABLE_MESSAGE: |
| processor.enable_outgoing_compression() |
| elif text == _DISABLE_MESSAGE: |
| processor.disable_outgoing_compression() |
| request.ws_stream.send_message(text, binary=False) |
| if text == _GOODBYE_MESSAGE: |
| return |
| |
| |
| # vi:sts=4 sw=4 et |
