# Copyright 2016 gRPC authors. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import logging import struct import h2 import h2.connection import messages_pb2 import twisted import twisted.internet import twisted.internet.protocol _READ_CHUNK_SIZE = 16384 _GRPC_HEADER_SIZE = 5 _MIN_SETTINGS_MAX_FRAME_SIZE = 16384 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) 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, _, pad_length=None, read_chunk_size=_READ_CHUNK_SIZE): # try to resume sending on all active streams (update might be for connection) for stream_id in self._send_remaining: self.default_send(stream_id, pad_length=pad_length, read_chunk_size=read_chunk_size) 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, pad_length=None, read_chunk_size=_READ_CHUNK_SIZE): 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, pad_length=pad_length, read_chunk_size=read_chunk_size) def default_send(self, stream_id, pad_length=None, read_chunk_size=_READ_CHUNK_SIZE): 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) padding_bytes = pad_length + 1 if pad_length is not None else 0 if lfcw - padding_bytes <= 0: logging.info( 'Stream %d. lfcw: %d. padding bytes: %d. not enough quota yet' % (stream_id, lfcw, padding_bytes)) break chunk_size = min(lfcw - padding_bytes, 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. includes %d total padding bytes' % (lfcw, self._send_offset, self._send_offset + bytes_to_send + padding_bytes, stream_id, padding_bytes)) # The receiver might allow sending frames larger than the http2 minimum # max frame size (16384), but this test should never send more than 16384 # for simplicity (which is always legal). if bytes_to_send + padding_bytes > _MIN_SETTINGS_MAX_FRAME_SIZE: raise ValueError("overload: sending %d" % (bytes_to_send + padding_bytes)) data = self._data_to_send[self._send_offset:self._send_offset + bytes_to_send] try: self._conn.send_data(stream_id, data, end_stream=False, pad_length=pad_length) 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 simple request for stream %d' % stream_id) return sr