# 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