# Copyright 2016, 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. import logging import messages_pb2 import struct import h2 import h2.connection import twisted import twisted.internet import twisted.internet.protocol _READ_CHUNK_SIZE = 16384 _GRPC_HEADER_SIZE = 5 class H2ProtocolBaseServer(twisted.internet.protocol.Protocol): def __init__(self): self._conn = h2.connection.H2Connection(client_side=False) self._recv_buffer = {} self._handlers = {} self._handlers['ConnectionMade'] = self.on_connection_made_default self._handlers['DataReceived'] = self.on_data_received_default self._handlers['WindowUpdated'] = self.on_window_update_default self._handlers['RequestReceived'] = self.on_request_received_default self._handlers['SendDone'] = self.on_send_done_default self._handlers['ConnectionLost'] = self.on_connection_lost self._handlers['PingAcknowledged'] = self.on_ping_acknowledged_default self._stream_status = {} self._send_remaining = {} self._outstanding_pings = 0 def set_handlers(self, handlers): self._handlers = handlers def connectionMade(self): self._handlers['ConnectionMade']() def connectionLost(self, reason): self._handlers['ConnectionLost'](reason) def on_connection_made_default(self): logging.info('Connection Made') self._conn.initiate_connection() self.transport.setTcpNoDelay(True) self.transport.write(self._conn.data_to_send()) def on_connection_lost(self, reason): logging.info('Disconnected %s' % reason) twisted.internet.reactor.callFromThread(twisted.internet.reactor.stop) def dataReceived(self, data): try: events = self._conn.receive_data(data) except h2.exceptions.ProtocolError: # this try/except block catches exceptions due to race between sending # GOAWAY and processing a response in flight. return if self._conn.data_to_send: self.transport.write(self._conn.data_to_send()) for event in events: if isinstance(event, h2.events.RequestReceived) and self._handlers.has_key('RequestReceived'): logging.info('RequestReceived Event for stream: %d' % event.stream_id) self._handlers['RequestReceived'](event) elif isinstance(event, h2.events.DataReceived) and self._handlers.has_key('DataReceived'): logging.info('DataReceived Event for stream: %d' % event.stream_id) self._handlers['DataReceived'](event) elif isinstance(event, h2.events.WindowUpdated) and self._handlers.has_key('WindowUpdated'): logging.info('WindowUpdated Event for stream: %d' % event.stream_id) self._handlers['WindowUpdated'](event) elif isinstance(event, h2.events.PingAcknowledged) and self._handlers.has_key('PingAcknowledged'): logging.info('PingAcknowledged Event') self._handlers['PingAcknowledged'](event) self.transport.write(self._conn.data_to_send()) def on_ping_acknowledged_default(self, event): logging.info('ping acknowledged') self._outstanding_pings -= 1 def on_data_received_default(self, event): self._conn.acknowledge_received_data(len(event.data), event.stream_id) self._recv_buffer[event.stream_id] += event.data def on_request_received_default(self, event): self._recv_buffer[event.stream_id] = '' self._stream_id = event.stream_id self._stream_status[event.stream_id] = True self._conn.send_headers( stream_id=event.stream_id, headers=[ (':status', '200'), ('content-type', 'application/grpc'), ('grpc-encoding', 'identity'), ('grpc-accept-encoding', 'identity,deflate,gzip'), ], ) self.transport.write(self._conn.data_to_send()) def on_window_update_default(self, event): # send pending data, if any self.default_send(event.stream_id) def send_reset_stream(self): self._conn.reset_stream(self._stream_id) self.transport.write(self._conn.data_to_send()) def setup_send(self, data_to_send, stream_id): logging.info('Setting up data to send for stream_id: %d' % stream_id) self._send_remaining[stream_id] = len(data_to_send) self._send_offset = 0 self._data_to_send = data_to_send self.default_send(stream_id) def default_send(self, stream_id): if not self._send_remaining.has_key(stream_id): # not setup to send data yet return while self._send_remaining[stream_id] > 0: lfcw = self._conn.local_flow_control_window(stream_id) if lfcw == 0: break chunk_size = min(lfcw, _READ_CHUNK_SIZE) bytes_to_send = min(chunk_size, self._send_remaining[stream_id]) logging.info('flow_control_window = %d. sending [%d:%d] stream_id %d' % (lfcw, self._send_offset, self._send_offset + bytes_to_send, stream_id)) data = self._data_to_send[self._send_offset : self._send_offset + bytes_to_send] try: self._conn.send_data(stream_id, data, False) except h2.exceptions.ProtocolError: logging.info('Stream %d is closed' % stream_id) break self._send_remaining[stream_id] -= bytes_to_send self._send_offset += bytes_to_send if self._send_remaining[stream_id] == 0: self._handlers['SendDone'](stream_id) def default_ping(self): logging.info('sending ping') self._outstanding_pings += 1 self._conn.ping(b'\x00'*8) self.transport.write(self._conn.data_to_send()) def on_send_done_default(self, stream_id): if self._stream_status[stream_id]: self._stream_status[stream_id] = False self.default_send_trailer(stream_id) else: logging.error('Stream %d is already closed' % stream_id) def default_send_trailer(self, stream_id): logging.info('Sending trailer for stream id %d' % stream_id) self._conn.send_headers(stream_id, headers=[ ('grpc-status', '0') ], end_stream=True ) self.transport.write(self._conn.data_to_send()) @staticmethod def default_response_data(response_size): sresp = messages_pb2.SimpleResponse() sresp.payload.body = b'\x00'*response_size serialized_resp_proto = sresp.SerializeToString() response_data = b'\x00' + struct.pack('i', len(serialized_resp_proto))[::-1] + serialized_resp_proto return response_data def parse_received_data(self, stream_id): """ returns a grpc framed string of bytes containing response proto of the size asked in request """ recv_buffer = self._recv_buffer[stream_id] grpc_msg_size = struct.unpack('i',recv_buffer[1:5][::-1])[0] if len(recv_buffer) != _GRPC_HEADER_SIZE + grpc_msg_size: return None req_proto_str = recv_buffer[5:5+grpc_msg_size] sr = messages_pb2.SimpleRequest() sr.ParseFromString(req_proto_str) logging.info('Parsed request for stream %d: response_size=%s' % (stream_id, sr.response_size)) return sr