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Diffstat (limited to 'testing/mochitest/pywebsocket/mod_pywebsocket/_stream_hixie75.py')
| -rw-r--r-- | testing/mochitest/pywebsocket/mod_pywebsocket/_stream_hixie75.py | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_hixie75.py b/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_hixie75.py new file mode 100644 index 000000000..94cf5b31b --- /dev/null +++ b/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_hixie75.py @@ -0,0 +1,229 @@ +# Copyright 2011, 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. + + +"""This file provides a class for parsing/building frames of the WebSocket +protocol version HyBi 00 and Hixie 75. + +Specification: +- HyBi 00 http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00 +- Hixie 75 http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-75 +""" + + +from mod_pywebsocket import common +from mod_pywebsocket._stream_base import BadOperationException +from mod_pywebsocket._stream_base import ConnectionTerminatedException +from mod_pywebsocket._stream_base import InvalidFrameException +from mod_pywebsocket._stream_base import StreamBase +from mod_pywebsocket._stream_base import UnsupportedFrameException +from mod_pywebsocket import util + + +class StreamHixie75(StreamBase): + """A class for parsing/building frames of the WebSocket protocol version + HyBi 00 and Hixie 75. + """ + + def __init__(self, request, enable_closing_handshake=False): + """Construct an instance. + + Args: + request: mod_python request. + enable_closing_handshake: to let StreamHixie75 perform closing + handshake as specified in HyBi 00, set + this option to True. + """ + + StreamBase.__init__(self, request) + + self._logger = util.get_class_logger(self) + + self._enable_closing_handshake = enable_closing_handshake + + self._request.client_terminated = False + self._request.server_terminated = False + + def send_message(self, message, end=True, binary=False): + """Send message. + + Args: + message: unicode string to send. + binary: not used in hixie75. + + Raises: + BadOperationException: when called on a server-terminated + connection. + """ + + if not end: + raise BadOperationException( + 'StreamHixie75 doesn\'t support send_message with end=False') + + if binary: + raise BadOperationException( + 'StreamHixie75 doesn\'t support send_message with binary=True') + + if self._request.server_terminated: + raise BadOperationException( + 'Requested send_message after sending out a closing handshake') + + self._write(''.join(['\x00', message.encode('utf-8'), '\xff'])) + + def _read_payload_length_hixie75(self): + """Reads a length header in a Hixie75 version frame with length. + + Raises: + ConnectionTerminatedException: when read returns empty string. + """ + + length = 0 + while True: + b_str = self._read(1) + b = ord(b_str) + length = length * 128 + (b & 0x7f) + if (b & 0x80) == 0: + break + return length + + def receive_message(self): + """Receive a WebSocket frame and return its payload an unicode string. + + Returns: + payload unicode string in a WebSocket frame. + + Raises: + ConnectionTerminatedException: when read returns empty + string. + BadOperationException: when called on a client-terminated + connection. + """ + + if self._request.client_terminated: + raise BadOperationException( + 'Requested receive_message after receiving a closing ' + 'handshake') + + while True: + # Read 1 byte. + # mp_conn.read will block if no bytes are available. + # Timeout is controlled by TimeOut directive of Apache. + frame_type_str = self.receive_bytes(1) + frame_type = ord(frame_type_str) + if (frame_type & 0x80) == 0x80: + # The payload length is specified in the frame. + # Read and discard. + length = self._read_payload_length_hixie75() + if length > 0: + _ = self.receive_bytes(length) + # 5.3 3. 12. if /type/ is 0xFF and /length/ is 0, then set the + # /client terminated/ flag and abort these steps. + if not self._enable_closing_handshake: + continue + + if frame_type == 0xFF and length == 0: + self._request.client_terminated = True + + if self._request.server_terminated: + self._logger.debug( + 'Received ack for server-initiated closing ' + 'handshake') + return None + + self._logger.debug( + 'Received client-initiated closing handshake') + + self._send_closing_handshake() + self._logger.debug( + 'Sent ack for client-initiated closing handshake') + return None + else: + # The payload is delimited with \xff. + bytes = self._read_until('\xff') + # The WebSocket protocol section 4.4 specifies that invalid + # characters must be replaced with U+fffd REPLACEMENT + # CHARACTER. + message = bytes.decode('utf-8', 'replace') + if frame_type == 0x00: + return message + # Discard data of other types. + + def _send_closing_handshake(self): + if not self._enable_closing_handshake: + raise BadOperationException( + 'Closing handshake is not supported in Hixie 75 protocol') + + self._request.server_terminated = True + + # 5.3 the server may decide to terminate the WebSocket connection by + # running through the following steps: + # 1. send a 0xFF byte and a 0x00 byte to the client to indicate the + # start of the closing handshake. + self._write('\xff\x00') + + def close_connection(self, unused_code='', unused_reason=''): + """Closes a WebSocket connection. + + Raises: + ConnectionTerminatedException: when closing handshake was + not successfull. + """ + + if self._request.server_terminated: + self._logger.debug( + 'Requested close_connection but server is already terminated') + return + + if not self._enable_closing_handshake: + self._request.server_terminated = True + self._logger.debug('Connection closed') + return + + self._send_closing_handshake() + self._logger.debug('Sent server-initiated closing handshake') + + # TODO(ukai): 2. wait until the /client terminated/ flag has been set, + # or until a server-defined timeout expires. + # + # For now, we expect receiving closing handshake right after sending + # out closing handshake, and if we couldn't receive non-handshake + # frame, we take it as ConnectionTerminatedException. + message = self.receive_message() + if message is not None: + raise ConnectionTerminatedException( + 'Didn\'t receive valid ack for closing handshake') + # TODO: 3. close the WebSocket connection. + # note: mod_python Connection (mp_conn) doesn't have close method. + + def send_ping(self, body): + raise BadOperationException( + 'StreamHixie75 doesn\'t support send_ping') + + +# vi:sts=4 sw=4 et |