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Diffstat (limited to 'testing/web-platform/tests/tools/pywebsocket/src/mod_pywebsocket/mux.py')
| -rw-r--r-- | testing/web-platform/tests/tools/pywebsocket/src/mod_pywebsocket/mux.py | 1889 |
1 files changed, 1889 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/pywebsocket/src/mod_pywebsocket/mux.py b/testing/web-platform/tests/tools/pywebsocket/src/mod_pywebsocket/mux.py new file mode 100644 index 000000000..76334685b --- /dev/null +++ b/testing/web-platform/tests/tools/pywebsocket/src/mod_pywebsocket/mux.py @@ -0,0 +1,1889 @@ +# Copyright 2012, 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 classes and helper functions for multiplexing extension. + +Specification: +http://tools.ietf.org/html/draft-ietf-hybi-websocket-multiplexing-06 +""" + + +import collections +import copy +import email +import email.parser +import logging +import math +import struct +import threading +import traceback + +from mod_pywebsocket import common +from mod_pywebsocket import handshake +from mod_pywebsocket import util +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_hybi import Frame +from mod_pywebsocket._stream_hybi import Stream +from mod_pywebsocket._stream_hybi import StreamOptions +from mod_pywebsocket._stream_hybi import create_binary_frame +from mod_pywebsocket._stream_hybi import create_closing_handshake_body +from mod_pywebsocket._stream_hybi import create_header +from mod_pywebsocket._stream_hybi import create_length_header +from mod_pywebsocket._stream_hybi import parse_frame +from mod_pywebsocket.handshake import hybi + + +_CONTROL_CHANNEL_ID = 0 +_DEFAULT_CHANNEL_ID = 1 + +_MUX_OPCODE_ADD_CHANNEL_REQUEST = 0 +_MUX_OPCODE_ADD_CHANNEL_RESPONSE = 1 +_MUX_OPCODE_FLOW_CONTROL = 2 +_MUX_OPCODE_DROP_CHANNEL = 3 +_MUX_OPCODE_NEW_CHANNEL_SLOT = 4 + +_MAX_CHANNEL_ID = 2 ** 29 - 1 + +_INITIAL_NUMBER_OF_CHANNEL_SLOTS = 64 +_INITIAL_QUOTA_FOR_CLIENT = 8 * 1024 + +_HANDSHAKE_ENCODING_IDENTITY = 0 +_HANDSHAKE_ENCODING_DELTA = 1 + +# We need only these status code for now. +_HTTP_BAD_RESPONSE_MESSAGES = { + common.HTTP_STATUS_BAD_REQUEST: 'Bad Request', +} + +# DropChannel reason code +# TODO(bashi): Define all reason code defined in -05 draft. +_DROP_CODE_NORMAL_CLOSURE = 1000 + +_DROP_CODE_INVALID_ENCAPSULATING_MESSAGE = 2001 +_DROP_CODE_CHANNEL_ID_TRUNCATED = 2002 +_DROP_CODE_ENCAPSULATED_FRAME_IS_TRUNCATED = 2003 +_DROP_CODE_UNKNOWN_MUX_OPCODE = 2004 +_DROP_CODE_INVALID_MUX_CONTROL_BLOCK = 2005 +_DROP_CODE_CHANNEL_ALREADY_EXISTS = 2006 +_DROP_CODE_NEW_CHANNEL_SLOT_VIOLATION = 2007 +_DROP_CODE_UNKNOWN_REQUEST_ENCODING = 2010 + +_DROP_CODE_SEND_QUOTA_VIOLATION = 3005 +_DROP_CODE_SEND_QUOTA_OVERFLOW = 3006 +_DROP_CODE_ACKNOWLEDGED = 3008 +_DROP_CODE_BAD_FRAGMENTATION = 3009 + + +class MuxUnexpectedException(Exception): + """Exception in handling multiplexing extension.""" + pass + + +# Temporary +class MuxNotImplementedException(Exception): + """Raised when a flow enters unimplemented code path.""" + pass + + +class LogicalConnectionClosedException(Exception): + """Raised when logical connection is gracefully closed.""" + pass + + +class PhysicalConnectionError(Exception): + """Raised when there is a physical connection error.""" + def __init__(self, drop_code, message=''): + super(PhysicalConnectionError, self).__init__( + 'code=%d, message=%r' % (drop_code, message)) + self.drop_code = drop_code + self.message = message + + +class LogicalChannelError(Exception): + """Raised when there is a logical channel error.""" + def __init__(self, channel_id, drop_code, message=''): + super(LogicalChannelError, self).__init__( + 'channel_id=%d, code=%d, message=%r' % ( + channel_id, drop_code, message)) + self.channel_id = channel_id + self.drop_code = drop_code + self.message = message + + +def _encode_channel_id(channel_id): + if channel_id < 0: + raise ValueError('Channel id %d must not be negative' % channel_id) + + if channel_id < 2 ** 7: + return chr(channel_id) + if channel_id < 2 ** 14: + return struct.pack('!H', 0x8000 + channel_id) + if channel_id < 2 ** 21: + first = chr(0xc0 + (channel_id >> 16)) + return first + struct.pack('!H', channel_id & 0xffff) + if channel_id < 2 ** 29: + return struct.pack('!L', 0xe0000000 + channel_id) + + raise ValueError('Channel id %d is too large' % channel_id) + + +def _encode_number(number): + return create_length_header(number, False) + + +def _create_add_channel_response(channel_id, encoded_handshake, + encoding=0, rejected=False): + if encoding != 0 and encoding != 1: + raise ValueError('Invalid encoding %d' % encoding) + + first_byte = ((_MUX_OPCODE_ADD_CHANNEL_RESPONSE << 5) | + (rejected << 4) | encoding) + block = (chr(first_byte) + + _encode_channel_id(channel_id) + + _encode_number(len(encoded_handshake)) + + encoded_handshake) + return block + + +def _create_drop_channel(channel_id, code=None, message=''): + if len(message) > 0 and code is None: + raise ValueError('Code must be specified if message is specified') + + first_byte = _MUX_OPCODE_DROP_CHANNEL << 5 + block = chr(first_byte) + _encode_channel_id(channel_id) + if code is None: + block += _encode_number(0) # Reason size + else: + reason = struct.pack('!H', code) + message + reason_size = _encode_number(len(reason)) + block += reason_size + reason + + return block + + +def _create_flow_control(channel_id, replenished_quota): + first_byte = _MUX_OPCODE_FLOW_CONTROL << 5 + block = (chr(first_byte) + + _encode_channel_id(channel_id) + + _encode_number(replenished_quota)) + return block + + +def _create_new_channel_slot(slots, send_quota): + if slots < 0 or send_quota < 0: + raise ValueError('slots and send_quota must be non-negative.') + first_byte = _MUX_OPCODE_NEW_CHANNEL_SLOT << 5 + block = (chr(first_byte) + + _encode_number(slots) + + _encode_number(send_quota)) + return block + + +def _create_fallback_new_channel_slot(): + first_byte = (_MUX_OPCODE_NEW_CHANNEL_SLOT << 5) | 1 # Set the F flag + block = (chr(first_byte) + _encode_number(0) + _encode_number(0)) + return block + + +def _parse_request_text(request_text): + request_line, header_lines = request_text.split('\r\n', 1) + + words = request_line.split(' ') + if len(words) != 3: + raise ValueError('Bad Request-Line syntax %r' % request_line) + [command, path, version] = words + if version != 'HTTP/1.1': + raise ValueError('Bad request version %r' % version) + + # email.parser.Parser() parses RFC 2822 (RFC 822) style headers. + # RFC 6455 refers RFC 2616 for handshake parsing, and RFC 2616 refers + # RFC 822. + headers = email.parser.Parser().parsestr(header_lines) + return command, path, version, headers + + +class _ControlBlock(object): + """A structure that holds parsing result of multiplexing control block. + Control block specific attributes will be added by _MuxFramePayloadParser. + (e.g. encoded_handshake will be added for AddChannelRequest and + AddChannelResponse) + """ + + def __init__(self, opcode): + self.opcode = opcode + + +class _MuxFramePayloadParser(object): + """A class that parses multiplexed frame payload.""" + + def __init__(self, payload): + self._data = payload + self._read_position = 0 + self._logger = util.get_class_logger(self) + + def read_channel_id(self): + """Reads channel id. + + Raises: + ValueError: when the payload doesn't contain + valid channel id. + """ + + remaining_length = len(self._data) - self._read_position + pos = self._read_position + if remaining_length == 0: + raise ValueError('Invalid channel id format') + + channel_id = ord(self._data[pos]) + channel_id_length = 1 + if channel_id & 0xe0 == 0xe0: + if remaining_length < 4: + raise ValueError('Invalid channel id format') + channel_id = struct.unpack('!L', + self._data[pos:pos+4])[0] & 0x1fffffff + channel_id_length = 4 + elif channel_id & 0xc0 == 0xc0: + if remaining_length < 3: + raise ValueError('Invalid channel id format') + channel_id = (((channel_id & 0x1f) << 16) + + struct.unpack('!H', self._data[pos+1:pos+3])[0]) + channel_id_length = 3 + elif channel_id & 0x80 == 0x80: + if remaining_length < 2: + raise ValueError('Invalid channel id format') + channel_id = struct.unpack('!H', + self._data[pos:pos+2])[0] & 0x3fff + channel_id_length = 2 + self._read_position += channel_id_length + + return channel_id + + def read_inner_frame(self): + """Reads an inner frame. + + Raises: + PhysicalConnectionError: when the inner frame is invalid. + """ + + if len(self._data) == self._read_position: + raise PhysicalConnectionError( + _DROP_CODE_ENCAPSULATED_FRAME_IS_TRUNCATED) + + bits = ord(self._data[self._read_position]) + self._read_position += 1 + fin = (bits & 0x80) == 0x80 + rsv1 = (bits & 0x40) == 0x40 + rsv2 = (bits & 0x20) == 0x20 + rsv3 = (bits & 0x10) == 0x10 + opcode = bits & 0xf + payload = self.remaining_data() + # Consume rest of the message which is payload data of the original + # frame. + self._read_position = len(self._data) + return fin, rsv1, rsv2, rsv3, opcode, payload + + def _read_number(self): + if self._read_position + 1 > len(self._data): + raise ValueError( + 'Cannot read the first byte of number field') + + number = ord(self._data[self._read_position]) + if number & 0x80 == 0x80: + raise ValueError( + 'The most significant bit of the first byte of number should ' + 'be unset') + self._read_position += 1 + pos = self._read_position + if number == 127: + if pos + 8 > len(self._data): + raise ValueError('Invalid number field') + self._read_position += 8 + number = struct.unpack('!Q', self._data[pos:pos+8])[0] + if number > 0x7FFFFFFFFFFFFFFF: + raise ValueError('Encoded number(%d) >= 2^63' % number) + if number <= 0xFFFF: + raise ValueError( + '%d should not be encoded by 9 bytes encoding' % number) + return number + if number == 126: + if pos + 2 > len(self._data): + raise ValueError('Invalid number field') + self._read_position += 2 + number = struct.unpack('!H', self._data[pos:pos+2])[0] + if number <= 125: + raise ValueError( + '%d should not be encoded by 3 bytes encoding' % number) + return number + + def _read_size_and_contents(self): + """Reads data that consists of followings: + - the size of the contents encoded the same way as payload length + of the WebSocket Protocol with 1 bit padding at the head. + - the contents. + """ + + try: + size = self._read_number() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + str(e)) + pos = self._read_position + if pos + size > len(self._data): + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Cannot read %d bytes data' % size) + + self._read_position += size + return self._data[pos:pos+size] + + def _read_add_channel_request(self, first_byte, control_block): + reserved = (first_byte >> 2) & 0x7 + if reserved != 0: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Reserved bits must be unset') + + # Invalid encoding will be handled by MuxHandler. + encoding = first_byte & 0x3 + try: + control_block.channel_id = self.read_channel_id() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK) + control_block.encoding = encoding + encoded_handshake = self._read_size_and_contents() + control_block.encoded_handshake = encoded_handshake + return control_block + + def _read_add_channel_response(self, first_byte, control_block): + reserved = (first_byte >> 2) & 0x3 + if reserved != 0: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Reserved bits must be unset') + + control_block.accepted = (first_byte >> 4) & 1 + control_block.encoding = first_byte & 0x3 + try: + control_block.channel_id = self.read_channel_id() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK) + control_block.encoded_handshake = self._read_size_and_contents() + return control_block + + def _read_flow_control(self, first_byte, control_block): + reserved = first_byte & 0x1f + if reserved != 0: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Reserved bits must be unset') + + try: + control_block.channel_id = self.read_channel_id() + control_block.send_quota = self._read_number() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + str(e)) + + return control_block + + def _read_drop_channel(self, first_byte, control_block): + reserved = first_byte & 0x1f + if reserved != 0: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Reserved bits must be unset') + + try: + control_block.channel_id = self.read_channel_id() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK) + reason = self._read_size_and_contents() + if len(reason) == 0: + control_block.drop_code = None + control_block.drop_message = '' + elif len(reason) >= 2: + control_block.drop_code = struct.unpack('!H', reason[:2])[0] + control_block.drop_message = reason[2:] + else: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Received DropChannel that conains only 1-byte reason') + return control_block + + def _read_new_channel_slot(self, first_byte, control_block): + reserved = first_byte & 0x1e + if reserved != 0: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Reserved bits must be unset') + control_block.fallback = first_byte & 1 + try: + control_block.slots = self._read_number() + control_block.send_quota = self._read_number() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + str(e)) + return control_block + + def read_control_blocks(self): + """Reads control block(s). + + Raises: + PhysicalConnectionError: when the payload contains invalid control + block(s). + StopIteration: when no control blocks left. + """ + + while self._read_position < len(self._data): + first_byte = ord(self._data[self._read_position]) + self._read_position += 1 + opcode = (first_byte >> 5) & 0x7 + control_block = _ControlBlock(opcode=opcode) + if opcode == _MUX_OPCODE_ADD_CHANNEL_REQUEST: + yield self._read_add_channel_request(first_byte, control_block) + elif opcode == _MUX_OPCODE_ADD_CHANNEL_RESPONSE: + yield self._read_add_channel_response( + first_byte, control_block) + elif opcode == _MUX_OPCODE_FLOW_CONTROL: + yield self._read_flow_control(first_byte, control_block) + elif opcode == _MUX_OPCODE_DROP_CHANNEL: + yield self._read_drop_channel(first_byte, control_block) + elif opcode == _MUX_OPCODE_NEW_CHANNEL_SLOT: + yield self._read_new_channel_slot(first_byte, control_block) + else: + raise PhysicalConnectionError( + _DROP_CODE_UNKNOWN_MUX_OPCODE, + 'Invalid opcode %d' % opcode) + + assert self._read_position == len(self._data) + raise StopIteration + + def remaining_data(self): + """Returns remaining data.""" + + return self._data[self._read_position:] + + +class _LogicalRequest(object): + """Mimics mod_python request.""" + + def __init__(self, channel_id, command, path, protocol, headers, + connection): + """Constructs an instance. + + Args: + channel_id: the channel id of the logical channel. + command: HTTP request command. + path: HTTP request path. + headers: HTTP headers. + connection: _LogicalConnection instance. + """ + + self.channel_id = channel_id + self.method = command + self.uri = path + self.protocol = protocol + self.headers_in = headers + self.connection = connection + self.server_terminated = False + self.client_terminated = False + + def is_https(self): + """Mimics request.is_https(). Returns False because this method is + used only by old protocols (hixie and hybi00). + """ + + return False + + +class _LogicalConnection(object): + """Mimics mod_python mp_conn.""" + + # For details, see the comment of set_read_state(). + STATE_ACTIVE = 1 + STATE_GRACEFULLY_CLOSED = 2 + STATE_TERMINATED = 3 + + def __init__(self, mux_handler, channel_id): + """Constructs an instance. + + Args: + mux_handler: _MuxHandler instance. + channel_id: channel id of this connection. + """ + + self._mux_handler = mux_handler + self._channel_id = channel_id + self._incoming_data = '' + + # - Protects _waiting_write_completion + # - Signals the thread waiting for completion of write by mux handler + self._write_condition = threading.Condition() + self._waiting_write_completion = False + + self._read_condition = threading.Condition() + self._read_state = self.STATE_ACTIVE + + def get_local_addr(self): + """Getter to mimic mp_conn.local_addr.""" + + return self._mux_handler.physical_connection.get_local_addr() + local_addr = property(get_local_addr) + + def get_remote_addr(self): + """Getter to mimic mp_conn.remote_addr.""" + + return self._mux_handler.physical_connection.get_remote_addr() + remote_addr = property(get_remote_addr) + + def get_memorized_lines(self): + """Gets memorized lines. Not supported.""" + + raise MuxUnexpectedException('_LogicalConnection does not support ' + 'get_memorized_lines') + + def write(self, data): + """Writes data. mux_handler sends data asynchronously. The caller will + be suspended until write done. + + Args: + data: data to be written. + + Raises: + MuxUnexpectedException: when called before finishing the previous + write. + """ + + try: + self._write_condition.acquire() + if self._waiting_write_completion: + raise MuxUnexpectedException( + 'Logical connection %d is already waiting the completion ' + 'of write' % self._channel_id) + + self._waiting_write_completion = True + self._mux_handler.send_data(self._channel_id, data) + self._write_condition.wait() + # TODO(tyoshino): Raise an exception if woke up by on_writer_done. + finally: + self._write_condition.release() + + def write_control_data(self, data): + """Writes data via the control channel. Don't wait finishing write + because this method can be called by mux dispatcher. + + Args: + data: data to be written. + """ + + self._mux_handler.send_control_data(data) + + def on_write_data_done(self): + """Called when sending data is completed.""" + + try: + self._write_condition.acquire() + if not self._waiting_write_completion: + raise MuxUnexpectedException( + 'Invalid call of on_write_data_done for logical ' + 'connection %d' % self._channel_id) + self._waiting_write_completion = False + self._write_condition.notify() + finally: + self._write_condition.release() + + def on_writer_done(self): + """Called by the mux handler when the writer thread has finished.""" + + try: + self._write_condition.acquire() + self._waiting_write_completion = False + self._write_condition.notify() + finally: + self._write_condition.release() + + + def append_frame_data(self, frame_data): + """Appends incoming frame data. Called when mux_handler dispatches + frame data to the corresponding application. + + Args: + frame_data: incoming frame data. + """ + + self._read_condition.acquire() + self._incoming_data += frame_data + self._read_condition.notify() + self._read_condition.release() + + def read(self, length): + """Reads data. Blocks until enough data has arrived via physical + connection. + + Args: + length: length of data to be read. + Raises: + LogicalConnectionClosedException: when closing handshake for this + logical channel has been received. + ConnectionTerminatedException: when the physical connection has + closed, or an error is caused on the reader thread. + """ + + self._read_condition.acquire() + while (self._read_state == self.STATE_ACTIVE and + len(self._incoming_data) < length): + self._read_condition.wait() + + try: + if self._read_state == self.STATE_GRACEFULLY_CLOSED: + raise LogicalConnectionClosedException( + 'Logical channel %d has closed.' % self._channel_id) + elif self._read_state == self.STATE_TERMINATED: + raise ConnectionTerminatedException( + 'Receiving %d byte failed. Logical channel (%d) closed' % + (length, self._channel_id)) + + value = self._incoming_data[:length] + self._incoming_data = self._incoming_data[length:] + finally: + self._read_condition.release() + + return value + + def set_read_state(self, new_state): + """Sets the state of this connection. Called when an event for this + connection has occurred. + + Args: + new_state: state to be set. new_state must be one of followings: + - STATE_GRACEFULLY_CLOSED: when closing handshake for this + connection has been received. + - STATE_TERMINATED: when the physical connection has closed or + DropChannel of this connection has received. + """ + + self._read_condition.acquire() + self._read_state = new_state + self._read_condition.notify() + self._read_condition.release() + + +class _InnerMessage(object): + """Holds the result of _InnerMessageBuilder.build(). + """ + + def __init__(self, opcode, payload): + self.opcode = opcode + self.payload = payload + + +class _InnerMessageBuilder(object): + """A class that holds the context of inner message fragmentation and + builds a message from fragmented inner frame(s). + """ + + def __init__(self): + self._control_opcode = None + self._pending_control_fragments = [] + self._message_opcode = None + self._pending_message_fragments = [] + self._frame_handler = self._handle_first + + def _handle_first(self, frame): + if frame.opcode == common.OPCODE_CONTINUATION: + raise InvalidFrameException('Sending invalid continuation opcode') + + if common.is_control_opcode(frame.opcode): + return self._process_first_fragmented_control(frame) + else: + return self._process_first_fragmented_message(frame) + + def _process_first_fragmented_control(self, frame): + self._control_opcode = frame.opcode + self._pending_control_fragments.append(frame.payload) + if not frame.fin: + self._frame_handler = self._handle_fragmented_control + return None + return self._reassemble_fragmented_control() + + def _process_first_fragmented_message(self, frame): + self._message_opcode = frame.opcode + self._pending_message_fragments.append(frame.payload) + if not frame.fin: + self._frame_handler = self._handle_fragmented_message + return None + return self._reassemble_fragmented_message() + + def _handle_fragmented_control(self, frame): + if frame.opcode != common.OPCODE_CONTINUATION: + raise InvalidFrameException( + 'Sending invalid opcode %d while sending fragmented control ' + 'message' % frame.opcode) + self._pending_control_fragments.append(frame.payload) + if not frame.fin: + return None + return self._reassemble_fragmented_control() + + def _reassemble_fragmented_control(self): + opcode = self._control_opcode + payload = ''.join(self._pending_control_fragments) + self._control_opcode = None + self._pending_control_fragments = [] + if self._message_opcode is not None: + self._frame_handler = self._handle_fragmented_message + else: + self._frame_handler = self._handle_first + return _InnerMessage(opcode, payload) + + def _handle_fragmented_message(self, frame): + # Sender can interleave a control message while sending fragmented + # messages. + if common.is_control_opcode(frame.opcode): + if self._control_opcode is not None: + raise MuxUnexpectedException( + 'Should not reach here(Bug in builder)') + return self._process_first_fragmented_control(frame) + + if frame.opcode != common.OPCODE_CONTINUATION: + raise InvalidFrameException( + 'Sending invalid opcode %d while sending fragmented message' % + frame.opcode) + self._pending_message_fragments.append(frame.payload) + if not frame.fin: + return None + return self._reassemble_fragmented_message() + + def _reassemble_fragmented_message(self): + opcode = self._message_opcode + payload = ''.join(self._pending_message_fragments) + self._message_opcode = None + self._pending_message_fragments = [] + self._frame_handler = self._handle_first + return _InnerMessage(opcode, payload) + + def build(self, frame): + """Build an inner message. Returns an _InnerMessage instance when + the given frame is the last fragmented frame. Returns None otherwise. + + Args: + frame: an inner frame. + Raises: + InvalidFrameException: when received invalid opcode. (e.g. + receiving non continuation data opcode but the fin flag of + the previous inner frame was not set.) + """ + + return self._frame_handler(frame) + + +class _LogicalStream(Stream): + """Mimics the Stream class. This class interprets multiplexed WebSocket + frames. + """ + + def __init__(self, request, stream_options, send_quota, receive_quota): + """Constructs an instance. + + Args: + request: _LogicalRequest instance. + stream_options: StreamOptions instance. + send_quota: Initial send quota. + receive_quota: Initial receive quota. + """ + + # Physical stream is responsible for masking. + stream_options.unmask_receive = False + Stream.__init__(self, request, stream_options) + + self._send_closed = False + self._send_quota = send_quota + # - Protects _send_closed and _send_quota + # - Signals the thread waiting for send quota replenished + self._send_condition = threading.Condition() + + # The opcode of the first frame in messages. + self._message_opcode = common.OPCODE_TEXT + # True when the last message was fragmented. + self._last_message_was_fragmented = False + + self._receive_quota = receive_quota + self._write_inner_frame_semaphore = threading.Semaphore() + + self._inner_message_builder = _InnerMessageBuilder() + + def _create_inner_frame(self, opcode, payload, end=True): + frame = Frame(fin=end, opcode=opcode, payload=payload) + for frame_filter in self._options.outgoing_frame_filters: + frame_filter.filter(frame) + + if len(payload) != len(frame.payload): + raise MuxUnexpectedException( + 'Mux extension must not be used after extensions which change ' + ' frame boundary') + + first_byte = ((frame.fin << 7) | (frame.rsv1 << 6) | + (frame.rsv2 << 5) | (frame.rsv3 << 4) | frame.opcode) + return chr(first_byte) + frame.payload + + def _write_inner_frame(self, opcode, payload, end=True): + payload_length = len(payload) + write_position = 0 + + try: + # An inner frame will be fragmented if there is no enough send + # quota. This semaphore ensures that fragmented inner frames are + # sent in order on the logical channel. + # Note that frames that come from other logical channels or + # multiplexing control blocks can be inserted between fragmented + # inner frames on the physical channel. + self._write_inner_frame_semaphore.acquire() + + # Consume an octet quota when this is the first fragmented frame. + if opcode != common.OPCODE_CONTINUATION: + try: + self._send_condition.acquire() + while (not self._send_closed) and self._send_quota == 0: + self._send_condition.wait() + + if self._send_closed: + raise BadOperationException( + 'Logical connection %d is closed' % + self._request.channel_id) + + self._send_quota -= 1 + finally: + self._send_condition.release() + + while write_position < payload_length: + try: + self._send_condition.acquire() + while (not self._send_closed) and self._send_quota == 0: + self._logger.debug( + 'No quota. Waiting FlowControl message for %d.' % + self._request.channel_id) + self._send_condition.wait() + + if self._send_closed: + raise BadOperationException( + 'Logical connection %d is closed' % + self.request._channel_id) + + remaining = payload_length - write_position + write_length = min(self._send_quota, remaining) + inner_frame_end = ( + end and + (write_position + write_length == payload_length)) + + inner_frame = self._create_inner_frame( + opcode, + payload[write_position:write_position+write_length], + inner_frame_end) + self._send_quota -= write_length + self._logger.debug('Consumed quota=%d, remaining=%d' % + (write_length, self._send_quota)) + finally: + self._send_condition.release() + + # Writing data will block the worker so we need to release + # _send_condition before writing. + self._logger.debug('Sending inner frame: %r' % inner_frame) + self._request.connection.write(inner_frame) + write_position += write_length + + opcode = common.OPCODE_CONTINUATION + + except ValueError, e: + raise BadOperationException(e) + finally: + self._write_inner_frame_semaphore.release() + + def replenish_send_quota(self, send_quota): + """Replenish send quota.""" + + try: + self._send_condition.acquire() + if self._send_quota + send_quota > 0x7FFFFFFFFFFFFFFF: + self._send_quota = 0 + raise LogicalChannelError( + self._request.channel_id, _DROP_CODE_SEND_QUOTA_OVERFLOW) + self._send_quota += send_quota + self._logger.debug('Replenished send quota for channel id %d: %d' % + (self._request.channel_id, self._send_quota)) + finally: + self._send_condition.notify() + self._send_condition.release() + + def consume_receive_quota(self, amount): + """Consumes receive quota. Returns False on failure.""" + + if self._receive_quota < amount: + self._logger.debug('Violate quota on channel id %d: %d < %d' % + (self._request.channel_id, + self._receive_quota, amount)) + return False + self._receive_quota -= amount + return True + + def send_message(self, message, end=True, binary=False): + """Override Stream.send_message.""" + + if self._request.server_terminated: + raise BadOperationException( + 'Requested send_message after sending out a closing handshake') + + if binary and isinstance(message, unicode): + raise BadOperationException( + 'Message for binary frame must be instance of str') + + if binary: + opcode = common.OPCODE_BINARY + else: + opcode = common.OPCODE_TEXT + message = message.encode('utf-8') + + for message_filter in self._options.outgoing_message_filters: + message = message_filter.filter(message, end, binary) + + if self._last_message_was_fragmented: + if opcode != self._message_opcode: + raise BadOperationException('Message types are different in ' + 'frames for the same message') + opcode = common.OPCODE_CONTINUATION + else: + self._message_opcode = opcode + + self._write_inner_frame(opcode, message, end) + self._last_message_was_fragmented = not end + + def _receive_frame(self): + """Overrides Stream._receive_frame. + + In addition to call Stream._receive_frame, this method adds the amount + of payload to receiving quota and sends FlowControl to the client. + We need to do it here because Stream.receive_message() handles + control frames internally. + """ + + opcode, payload, fin, rsv1, rsv2, rsv3 = Stream._receive_frame(self) + amount = len(payload) + # Replenish extra one octet when receiving the first fragmented frame. + if opcode != common.OPCODE_CONTINUATION: + amount += 1 + self._receive_quota += amount + frame_data = _create_flow_control(self._request.channel_id, + amount) + self._logger.debug('Sending flow control for %d, replenished=%d' % + (self._request.channel_id, amount)) + self._request.connection.write_control_data(frame_data) + return opcode, payload, fin, rsv1, rsv2, rsv3 + + def _get_message_from_frame(self, frame): + """Overrides Stream._get_message_from_frame. + """ + + try: + inner_message = self._inner_message_builder.build(frame) + except InvalidFrameException: + raise LogicalChannelError( + self._request.channel_id, _DROP_CODE_BAD_FRAGMENTATION) + + if inner_message is None: + return None + self._original_opcode = inner_message.opcode + return inner_message.payload + + def receive_message(self): + """Overrides Stream.receive_message.""" + + # Just call Stream.receive_message(), but catch + # LogicalConnectionClosedException, which is raised when the logical + # connection has closed gracefully. + try: + return Stream.receive_message(self) + except LogicalConnectionClosedException, e: + self._logger.debug('%s', e) + return None + + def _send_closing_handshake(self, code, reason): + """Overrides Stream._send_closing_handshake.""" + + body = create_closing_handshake_body(code, reason) + self._logger.debug('Sending closing handshake for %d: (%r, %r)' % + (self._request.channel_id, code, reason)) + self._write_inner_frame(common.OPCODE_CLOSE, body, end=True) + + self._request.server_terminated = True + + def send_ping(self, body=''): + """Overrides Stream.send_ping""" + + self._logger.debug('Sending ping on logical channel %d: %r' % + (self._request.channel_id, body)) + self._write_inner_frame(common.OPCODE_PING, body, end=True) + + self._ping_queue.append(body) + + def _send_pong(self, body): + """Overrides Stream._send_pong""" + + self._logger.debug('Sending pong on logical channel %d: %r' % + (self._request.channel_id, body)) + self._write_inner_frame(common.OPCODE_PONG, body, end=True) + + def close_connection(self, code=common.STATUS_NORMAL_CLOSURE, reason=''): + """Overrides Stream.close_connection.""" + + # TODO(bashi): Implement + self._logger.debug('Closing logical connection %d' % + self._request.channel_id) + self._request.server_terminated = True + + def stop_sending(self): + """Stops accepting new send operation (_write_inner_frame).""" + + self._send_condition.acquire() + self._send_closed = True + self._send_condition.notify() + self._send_condition.release() + + +class _OutgoingData(object): + """A structure that holds data to be sent via physical connection and + origin of the data. + """ + + def __init__(self, channel_id, data): + self.channel_id = channel_id + self.data = data + + +class _PhysicalConnectionWriter(threading.Thread): + """A thread that is responsible for writing data to physical connection. + + TODO(bashi): Make sure there is no thread-safety problem when the reader + thread reads data from the same socket at a time. + """ + + def __init__(self, mux_handler): + """Constructs an instance. + + Args: + mux_handler: _MuxHandler instance. + """ + + threading.Thread.__init__(self) + self._logger = util.get_class_logger(self) + self._mux_handler = mux_handler + self.setDaemon(True) + + # When set, make this thread stop accepting new data, flush pending + # data and exit. + self._stop_requested = False + # The close code of the physical connection. + self._close_code = common.STATUS_NORMAL_CLOSURE + # Deque for passing write data. It's protected by _deque_condition + # until _stop_requested is set. + self._deque = collections.deque() + # - Protects _deque, _stop_requested and _close_code + # - Signals threads waiting for them to be available + self._deque_condition = threading.Condition() + + def put_outgoing_data(self, data): + """Puts outgoing data. + + Args: + data: _OutgoingData instance. + + Raises: + BadOperationException: when the thread has been requested to + terminate. + """ + + try: + self._deque_condition.acquire() + if self._stop_requested: + raise BadOperationException('Cannot write data anymore') + + self._deque.append(data) + self._deque_condition.notify() + finally: + self._deque_condition.release() + + def _write_data(self, outgoing_data): + message = (_encode_channel_id(outgoing_data.channel_id) + + outgoing_data.data) + try: + self._mux_handler.physical_stream.send_message( + message=message, end=True, binary=True) + except Exception, e: + util.prepend_message_to_exception( + 'Failed to send message to %r: ' % + (self._mux_handler.physical_connection.remote_addr,), e) + raise + + # TODO(bashi): It would be better to block the thread that sends + # control data as well. + if outgoing_data.channel_id != _CONTROL_CHANNEL_ID: + self._mux_handler.notify_write_data_done(outgoing_data.channel_id) + + def run(self): + try: + self._deque_condition.acquire() + while not self._stop_requested: + if len(self._deque) == 0: + self._deque_condition.wait() + continue + + outgoing_data = self._deque.popleft() + + self._deque_condition.release() + self._write_data(outgoing_data) + self._deque_condition.acquire() + + # Flush deque. + # + # At this point, self._deque_condition is always acquired. + try: + while len(self._deque) > 0: + outgoing_data = self._deque.popleft() + self._write_data(outgoing_data) + finally: + self._deque_condition.release() + + # Close physical connection. + try: + # Don't wait the response here. The response will be read + # by the reader thread. + self._mux_handler.physical_stream.close_connection( + self._close_code, wait_response=False) + except Exception, e: + util.prepend_message_to_exception( + 'Failed to close the physical connection: %r' % e) + raise + finally: + self._mux_handler.notify_writer_done() + + def stop(self, close_code=common.STATUS_NORMAL_CLOSURE): + """Stops the writer thread.""" + + self._deque_condition.acquire() + self._stop_requested = True + self._close_code = close_code + self._deque_condition.notify() + self._deque_condition.release() + + +class _PhysicalConnectionReader(threading.Thread): + """A thread that is responsible for reading data from physical connection. + """ + + def __init__(self, mux_handler): + """Constructs an instance. + + Args: + mux_handler: _MuxHandler instance. + """ + + threading.Thread.__init__(self) + self._logger = util.get_class_logger(self) + self._mux_handler = mux_handler + self.setDaemon(True) + + def run(self): + while True: + try: + physical_stream = self._mux_handler.physical_stream + message = physical_stream.receive_message() + if message is None: + break + # Below happens only when a data message is received. + opcode = physical_stream.get_last_received_opcode() + if opcode != common.OPCODE_BINARY: + self._mux_handler.fail_physical_connection( + _DROP_CODE_INVALID_ENCAPSULATING_MESSAGE, + 'Received a text message on physical connection') + break + + except ConnectionTerminatedException, e: + self._logger.debug('%s', e) + break + + try: + self._mux_handler.dispatch_message(message) + except PhysicalConnectionError, e: + self._mux_handler.fail_physical_connection( + e.drop_code, e.message) + break + except LogicalChannelError, e: + self._mux_handler.fail_logical_channel( + e.channel_id, e.drop_code, e.message) + except Exception, e: + self._logger.debug(traceback.format_exc()) + break + + self._mux_handler.notify_reader_done() + + +class _Worker(threading.Thread): + """A thread that is responsible for running the corresponding application + handler. + """ + + def __init__(self, mux_handler, request): + """Constructs an instance. + + Args: + mux_handler: _MuxHandler instance. + request: _LogicalRequest instance. + """ + + threading.Thread.__init__(self) + self._logger = util.get_class_logger(self) + self._mux_handler = mux_handler + self._request = request + self.setDaemon(True) + + def run(self): + self._logger.debug('Logical channel worker started. (id=%d)' % + self._request.channel_id) + try: + # Non-critical exceptions will be handled by dispatcher. + self._mux_handler.dispatcher.transfer_data(self._request) + except LogicalChannelError, e: + self._mux_handler.fail_logical_channel( + e.channel_id, e.drop_code, e.message) + finally: + self._mux_handler.notify_worker_done(self._request.channel_id) + + +class _MuxHandshaker(hybi.Handshaker): + """Opening handshake processor for multiplexing.""" + + _DUMMY_WEBSOCKET_KEY = 'dGhlIHNhbXBsZSBub25jZQ==' + + def __init__(self, request, dispatcher, send_quota, receive_quota): + """Constructs an instance. + Args: + request: _LogicalRequest instance. + dispatcher: Dispatcher instance (dispatch.Dispatcher). + send_quota: Initial send quota. + receive_quota: Initial receive quota. + """ + + hybi.Handshaker.__init__(self, request, dispatcher) + self._send_quota = send_quota + self._receive_quota = receive_quota + + # Append headers which should not be included in handshake field of + # AddChannelRequest. + # TODO(bashi): Make sure whether we should raise exception when + # these headers are included already. + request.headers_in[common.UPGRADE_HEADER] = ( + common.WEBSOCKET_UPGRADE_TYPE) + request.headers_in[common.SEC_WEBSOCKET_VERSION_HEADER] = ( + str(common.VERSION_HYBI_LATEST)) + request.headers_in[common.SEC_WEBSOCKET_KEY_HEADER] = ( + self._DUMMY_WEBSOCKET_KEY) + + def _create_stream(self, stream_options): + """Override hybi.Handshaker._create_stream.""" + + self._logger.debug('Creating logical stream for %d' % + self._request.channel_id) + return _LogicalStream( + self._request, stream_options, self._send_quota, + self._receive_quota) + + def _create_handshake_response(self, accept): + """Override hybi._create_handshake_response.""" + + response = [] + + response.append('HTTP/1.1 101 Switching Protocols\r\n') + + # Upgrade and Sec-WebSocket-Accept should be excluded. + response.append('%s: %s\r\n' % ( + common.CONNECTION_HEADER, common.UPGRADE_CONNECTION_TYPE)) + if self._request.ws_protocol is not None: + response.append('%s: %s\r\n' % ( + common.SEC_WEBSOCKET_PROTOCOL_HEADER, + self._request.ws_protocol)) + if (self._request.ws_extensions is not None and + len(self._request.ws_extensions) != 0): + response.append('%s: %s\r\n' % ( + common.SEC_WEBSOCKET_EXTENSIONS_HEADER, + common.format_extensions(self._request.ws_extensions))) + response.append('\r\n') + + return ''.join(response) + + def _send_handshake(self, accept): + """Override hybi.Handshaker._send_handshake.""" + + # Don't send handshake response for the default channel + if self._request.channel_id == _DEFAULT_CHANNEL_ID: + return + + handshake_response = self._create_handshake_response(accept) + frame_data = _create_add_channel_response( + self._request.channel_id, + handshake_response) + self._logger.debug('Sending handshake response for %d: %r' % + (self._request.channel_id, frame_data)) + self._request.connection.write_control_data(frame_data) + + +class _LogicalChannelData(object): + """A structure that holds information about logical channel. + """ + + def __init__(self, request, worker): + self.request = request + self.worker = worker + self.drop_code = _DROP_CODE_NORMAL_CLOSURE + self.drop_message = '' + + +class _HandshakeDeltaBase(object): + """A class that holds information for delta-encoded handshake.""" + + def __init__(self, headers): + self._headers = headers + + def create_headers(self, delta=None): + """Creates request headers for an AddChannelRequest that has + delta-encoded handshake. + + Args: + delta: headers should be overridden. + """ + + headers = copy.copy(self._headers) + if delta: + for key, value in delta.items(): + # The spec requires that a header with an empty value is + # removed from the delta base. + if len(value) == 0 and headers.has_key(key): + del headers[key] + else: + headers[key] = value + return headers + + +class _MuxHandler(object): + """Multiplexing handler. When a handler starts, it launches three + threads; the reader thread, the writer thread, and a worker thread. + + The reader thread reads data from the physical stream, i.e., the + ws_stream object of the underlying websocket connection. The reader + thread interprets multiplexed frames and dispatches them to logical + channels. Methods of this class are mostly called by the reader thread. + + The writer thread sends multiplexed frames which are created by + logical channels via the physical connection. + + The worker thread launched at the starting point handles the + "Implicitly Opened Connection". If multiplexing handler receives + an AddChannelRequest and accepts it, the handler will launch a new worker + thread and dispatch the request to it. + """ + + def __init__(self, request, dispatcher): + """Constructs an instance. + + Args: + request: mod_python request of the physical connection. + dispatcher: Dispatcher instance (dispatch.Dispatcher). + """ + + self.original_request = request + self.dispatcher = dispatcher + self.physical_connection = request.connection + self.physical_stream = request.ws_stream + self._logger = util.get_class_logger(self) + self._logical_channels = {} + self._logical_channels_condition = threading.Condition() + # Holds client's initial quota + self._channel_slots = collections.deque() + self._handshake_base = None + self._worker_done_notify_received = False + self._reader = None + self._writer = None + + def start(self): + """Starts the handler. + + Raises: + MuxUnexpectedException: when the handler already started, or when + opening handshake of the default channel fails. + """ + + if self._reader or self._writer: + raise MuxUnexpectedException('MuxHandler already started') + + self._reader = _PhysicalConnectionReader(self) + self._writer = _PhysicalConnectionWriter(self) + self._reader.start() + self._writer.start() + + # Create "Implicitly Opened Connection". + logical_connection = _LogicalConnection(self, _DEFAULT_CHANNEL_ID) + headers = copy.copy(self.original_request.headers_in) + # Add extensions for logical channel. + headers[common.SEC_WEBSOCKET_EXTENSIONS_HEADER] = ( + common.format_extensions( + self.original_request.mux_processor.extensions())) + self._handshake_base = _HandshakeDeltaBase(headers) + logical_request = _LogicalRequest( + _DEFAULT_CHANNEL_ID, + self.original_request.method, + self.original_request.uri, + self.original_request.protocol, + self._handshake_base.create_headers(), + logical_connection) + # Client's send quota for the implicitly opened connection is zero, + # but we will send FlowControl later so set the initial quota to + # _INITIAL_QUOTA_FOR_CLIENT. + self._channel_slots.append(_INITIAL_QUOTA_FOR_CLIENT) + send_quota = self.original_request.mux_processor.quota() + if not self._do_handshake_for_logical_request( + logical_request, send_quota=send_quota): + raise MuxUnexpectedException( + 'Failed handshake on the default channel id') + self._add_logical_channel(logical_request) + + # Send FlowControl for the implicitly opened connection. + frame_data = _create_flow_control(_DEFAULT_CHANNEL_ID, + _INITIAL_QUOTA_FOR_CLIENT) + logical_request.connection.write_control_data(frame_data) + + def add_channel_slots(self, slots, send_quota): + """Adds channel slots. + + Args: + slots: number of slots to be added. + send_quota: initial send quota for slots. + """ + + self._channel_slots.extend([send_quota] * slots) + # Send NewChannelSlot to client. + frame_data = _create_new_channel_slot(slots, send_quota) + self.send_control_data(frame_data) + + def wait_until_done(self, timeout=None): + """Waits until all workers are done. Returns False when timeout has + occurred. Returns True on success. + + Args: + timeout: timeout in sec. + """ + + self._logical_channels_condition.acquire() + try: + while len(self._logical_channels) > 0: + self._logger.debug('Waiting workers(%d)...' % + len(self._logical_channels)) + self._worker_done_notify_received = False + self._logical_channels_condition.wait(timeout) + if not self._worker_done_notify_received: + self._logger.debug('Waiting worker(s) timed out') + return False + finally: + self._logical_channels_condition.release() + + # Flush pending outgoing data + self._writer.stop() + self._writer.join() + + return True + + def notify_write_data_done(self, channel_id): + """Called by the writer thread when a write operation has done. + + Args: + channel_id: objective channel id. + """ + + try: + self._logical_channels_condition.acquire() + if channel_id in self._logical_channels: + channel_data = self._logical_channels[channel_id] + channel_data.request.connection.on_write_data_done() + else: + self._logger.debug('Seems that logical channel for %d has gone' + % channel_id) + finally: + self._logical_channels_condition.release() + + def send_control_data(self, data): + """Sends data via the control channel. + + Args: + data: data to be sent. + """ + + self._writer.put_outgoing_data(_OutgoingData( + channel_id=_CONTROL_CHANNEL_ID, data=data)) + + def send_data(self, channel_id, data): + """Sends data via given logical channel. This method is called by + worker threads. + + Args: + channel_id: objective channel id. + data: data to be sent. + """ + + self._writer.put_outgoing_data(_OutgoingData( + channel_id=channel_id, data=data)) + + def _send_drop_channel(self, channel_id, code=None, message=''): + frame_data = _create_drop_channel(channel_id, code, message) + self._logger.debug( + 'Sending drop channel for channel id %d' % channel_id) + self.send_control_data(frame_data) + + def _send_error_add_channel_response(self, channel_id, status=None): + if status is None: + status = common.HTTP_STATUS_BAD_REQUEST + + if status in _HTTP_BAD_RESPONSE_MESSAGES: + message = _HTTP_BAD_RESPONSE_MESSAGES[status] + else: + self._logger.debug('Response message for %d is not found' % status) + message = '???' + + response = 'HTTP/1.1 %d %s\r\n\r\n' % (status, message) + frame_data = _create_add_channel_response(channel_id, + encoded_handshake=response, + encoding=0, rejected=True) + self.send_control_data(frame_data) + + def _create_logical_request(self, block): + if block.channel_id == _CONTROL_CHANNEL_ID: + # TODO(bashi): Raise PhysicalConnectionError with code 2006 + # instead of MuxUnexpectedException. + raise MuxUnexpectedException( + 'Received the control channel id (0) as objective channel ' + 'id for AddChannel') + + if block.encoding > _HANDSHAKE_ENCODING_DELTA: + raise PhysicalConnectionError( + _DROP_CODE_UNKNOWN_REQUEST_ENCODING) + + method, path, version, headers = _parse_request_text( + block.encoded_handshake) + if block.encoding == _HANDSHAKE_ENCODING_DELTA: + headers = self._handshake_base.create_headers(headers) + + connection = _LogicalConnection(self, block.channel_id) + request = _LogicalRequest(block.channel_id, method, path, version, + headers, connection) + return request + + def _do_handshake_for_logical_request(self, request, send_quota=0): + try: + receive_quota = self._channel_slots.popleft() + except IndexError: + raise LogicalChannelError( + request.channel_id, _DROP_CODE_NEW_CHANNEL_SLOT_VIOLATION) + + handshaker = _MuxHandshaker(request, self.dispatcher, + send_quota, receive_quota) + try: + handshaker.do_handshake() + except handshake.VersionException, e: + self._logger.info('%s', e) + self._send_error_add_channel_response( + request.channel_id, status=common.HTTP_STATUS_BAD_REQUEST) + return False + except handshake.HandshakeException, e: + # TODO(bashi): Should we _Fail the Logical Channel_ with 3001 + # instead? + self._logger.info('%s', e) + self._send_error_add_channel_response(request.channel_id, + status=e.status) + return False + except handshake.AbortedByUserException, e: + self._logger.info('%s', e) + self._send_error_add_channel_response(request.channel_id) + return False + + return True + + def _add_logical_channel(self, logical_request): + try: + self._logical_channels_condition.acquire() + if logical_request.channel_id in self._logical_channels: + self._logger.debug('Channel id %d already exists' % + logical_request.channel_id) + raise PhysicalConnectionError( + _DROP_CODE_CHANNEL_ALREADY_EXISTS, + 'Channel id %d already exists' % + logical_request.channel_id) + worker = _Worker(self, logical_request) + channel_data = _LogicalChannelData(logical_request, worker) + self._logical_channels[logical_request.channel_id] = channel_data + worker.start() + finally: + self._logical_channels_condition.release() + + def _process_add_channel_request(self, block): + try: + logical_request = self._create_logical_request(block) + except ValueError, e: + self._logger.debug('Failed to create logical request: %r' % e) + self._send_error_add_channel_response( + block.channel_id, status=common.HTTP_STATUS_BAD_REQUEST) + return + if self._do_handshake_for_logical_request(logical_request): + if block.encoding == _HANDSHAKE_ENCODING_IDENTITY: + # Update handshake base. + # TODO(bashi): Make sure this is the right place to update + # handshake base. + self._handshake_base = _HandshakeDeltaBase( + logical_request.headers_in) + self._add_logical_channel(logical_request) + else: + self._send_error_add_channel_response( + block.channel_id, status=common.HTTP_STATUS_BAD_REQUEST) + + def _process_flow_control(self, block): + try: + self._logical_channels_condition.acquire() + if not block.channel_id in self._logical_channels: + return + channel_data = self._logical_channels[block.channel_id] + channel_data.request.ws_stream.replenish_send_quota( + block.send_quota) + finally: + self._logical_channels_condition.release() + + def _process_drop_channel(self, block): + self._logger.debug( + 'DropChannel received for %d: code=%r, reason=%r' % + (block.channel_id, block.drop_code, block.drop_message)) + try: + self._logical_channels_condition.acquire() + if not block.channel_id in self._logical_channels: + return + channel_data = self._logical_channels[block.channel_id] + channel_data.drop_code = _DROP_CODE_ACKNOWLEDGED + + # Close the logical channel + channel_data.request.connection.set_read_state( + _LogicalConnection.STATE_TERMINATED) + channel_data.request.ws_stream.stop_sending() + finally: + self._logical_channels_condition.release() + + def _process_control_blocks(self, parser): + for control_block in parser.read_control_blocks(): + opcode = control_block.opcode + self._logger.debug('control block received, opcode: %d' % opcode) + if opcode == _MUX_OPCODE_ADD_CHANNEL_REQUEST: + self._process_add_channel_request(control_block) + elif opcode == _MUX_OPCODE_ADD_CHANNEL_RESPONSE: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Received AddChannelResponse') + elif opcode == _MUX_OPCODE_FLOW_CONTROL: + self._process_flow_control(control_block) + elif opcode == _MUX_OPCODE_DROP_CHANNEL: + self._process_drop_channel(control_block) + elif opcode == _MUX_OPCODE_NEW_CHANNEL_SLOT: + raise PhysicalConnectionError( + _DROP_CODE_INVALID_MUX_CONTROL_BLOCK, + 'Received NewChannelSlot') + else: + raise MuxUnexpectedException( + 'Unexpected opcode %r' % opcode) + + def _process_logical_frame(self, channel_id, parser): + self._logger.debug('Received a frame. channel id=%d' % channel_id) + try: + self._logical_channels_condition.acquire() + if not channel_id in self._logical_channels: + # We must ignore the message for an inactive channel. + return + channel_data = self._logical_channels[channel_id] + fin, rsv1, rsv2, rsv3, opcode, payload = parser.read_inner_frame() + consuming_byte = len(payload) + if opcode != common.OPCODE_CONTINUATION: + consuming_byte += 1 + if not channel_data.request.ws_stream.consume_receive_quota( + consuming_byte): + # The client violates quota. Close logical channel. + raise LogicalChannelError( + channel_id, _DROP_CODE_SEND_QUOTA_VIOLATION) + header = create_header(opcode, len(payload), fin, rsv1, rsv2, rsv3, + mask=False) + frame_data = header + payload + channel_data.request.connection.append_frame_data(frame_data) + finally: + self._logical_channels_condition.release() + + def dispatch_message(self, message): + """Dispatches message. The reader thread calls this method. + + Args: + message: a message that contains encapsulated frame. + Raises: + PhysicalConnectionError: if the message contains physical + connection level errors. + LogicalChannelError: if the message contains logical channel + level errors. + """ + + parser = _MuxFramePayloadParser(message) + try: + channel_id = parser.read_channel_id() + except ValueError, e: + raise PhysicalConnectionError(_DROP_CODE_CHANNEL_ID_TRUNCATED) + if channel_id == _CONTROL_CHANNEL_ID: + self._process_control_blocks(parser) + else: + self._process_logical_frame(channel_id, parser) + + def notify_worker_done(self, channel_id): + """Called when a worker has finished. + + Args: + channel_id: channel id corresponded with the worker. + """ + + self._logger.debug('Worker for channel id %d terminated' % channel_id) + try: + self._logical_channels_condition.acquire() + if not channel_id in self._logical_channels: + raise MuxUnexpectedException( + 'Channel id %d not found' % channel_id) + channel_data = self._logical_channels.pop(channel_id) + finally: + self._worker_done_notify_received = True + self._logical_channels_condition.notify() + self._logical_channels_condition.release() + + if not channel_data.request.server_terminated: + self._send_drop_channel( + channel_id, code=channel_data.drop_code, + message=channel_data.drop_message) + + def notify_reader_done(self): + """This method is called by the reader thread when the reader has + finished. + """ + + self._logger.debug( + 'Termiating all logical connections waiting for incoming data ' + '...') + self._logical_channels_condition.acquire() + for channel_data in self._logical_channels.values(): + try: + channel_data.request.connection.set_read_state( + _LogicalConnection.STATE_TERMINATED) + except Exception: + self._logger.debug(traceback.format_exc()) + self._logical_channels_condition.release() + + def notify_writer_done(self): + """This method is called by the writer thread when the writer has + finished. + """ + + self._logger.debug( + 'Termiating all logical connections waiting for write ' + 'completion ...') + self._logical_channels_condition.acquire() + for channel_data in self._logical_channels.values(): + try: + channel_data.request.connection.on_writer_done() + except Exception: + self._logger.debug(traceback.format_exc()) + self._logical_channels_condition.release() + + def fail_physical_connection(self, code, message): + """Fail the physical connection. + + Args: + code: drop reason code. + message: drop message. + """ + + self._logger.debug('Failing the physical connection...') + self._send_drop_channel(_CONTROL_CHANNEL_ID, code, message) + self._writer.stop(common.STATUS_INTERNAL_ENDPOINT_ERROR) + + def fail_logical_channel(self, channel_id, code, message): + """Fail a logical channel. + + Args: + channel_id: channel id. + code: drop reason code. + message: drop message. + """ + + self._logger.debug('Failing logical channel %d...' % channel_id) + try: + self._logical_channels_condition.acquire() + if channel_id in self._logical_channels: + channel_data = self._logical_channels[channel_id] + # Close the logical channel. notify_worker_done() will be + # called later and it will send DropChannel. + channel_data.drop_code = code + channel_data.drop_message = message + + channel_data.request.connection.set_read_state( + _LogicalConnection.STATE_TERMINATED) + channel_data.request.ws_stream.stop_sending() + else: + self._send_drop_channel(channel_id, code, message) + finally: + self._logical_channels_condition.release() + + +def use_mux(request): + return hasattr(request, 'mux_processor') and ( + request.mux_processor.is_active()) + + +def start(request, dispatcher): + mux_handler = _MuxHandler(request, dispatcher) + mux_handler.start() + + mux_handler.add_channel_slots(_INITIAL_NUMBER_OF_CHANNEL_SLOTS, + _INITIAL_QUOTA_FOR_CLIENT) + + mux_handler.wait_until_done() + + +# vi:sts=4 sw=4 et |