import logging from enum import Enum, IntEnum from typing import Dict, List, Optional, Set import pylsqpack from aioquic.buffer import Buffer, BufferReadError, encode_uint_var from aioquic.h3.events import ( DataReceived, H3Event, Headers, HeadersReceived, PushPromiseReceived, ) from aioquic.h3.exceptions import NoAvailablePushIDError from aioquic.quic.connection import QuicConnection, stream_is_unidirectional from aioquic.quic.events import QuicEvent, StreamDataReceived from aioquic.quic.logger import QuicLoggerTrace logger = logging.getLogger("http3") H3_ALPN = ["h3-29", "h3-28", "h3-27"] class ErrorCode(IntEnum): HTTP_NO_ERROR = 0x100 HTTP_GENERAL_PROTOCOL_ERROR = 0x101 HTTP_INTERNAL_ERROR = 0x102 HTTP_STREAM_CREATION_ERROR = 0x103 HTTP_CLOSED_CRITICAL_STREAM = 0x104 HTTP_FRAME_UNEXPECTED = 0x105 HTTP_FRAME_ERROR = 0x106 HTTP_EXCESSIVE_LOAD = 0x107 HTTP_ID_ERROR = 0x108 HTTP_SETTINGS_ERROR = 0x109 HTTP_MISSING_SETTINGS = 0x10A HTTP_REQUEST_REJECTED = 0x10B HTTP_REQUEST_CANCELLED = 0x10C HTTP_REQUEST_INCOMPLETE = 0x10D HTTP_EARLY_RESPONSE = 0x10E HTTP_CONNECT_ERROR = 0x10F HTTP_VERSION_FALLBACK = 0x110 HTTP_QPACK_DECOMPRESSION_FAILED = 0x200 HTTP_QPACK_ENCODER_STREAM_ERROR = 0x201 HTTP_QPACK_DECODER_STREAM_ERROR = 0x202 class FrameType(IntEnum): DATA = 0x0 HEADERS = 0x1 PRIORITY = 0x2 CANCEL_PUSH = 0x3 SETTINGS = 0x4 PUSH_PROMISE = 0x5 GOAWAY = 0x7 MAX_PUSH_ID = 0xD DUPLICATE_PUSH = 0xE class HeadersState(Enum): INITIAL = 0 AFTER_HEADERS = 1 AFTER_TRAILERS = 2 class Setting(IntEnum): QPACK_MAX_TABLE_CAPACITY = 1 SETTINGS_MAX_HEADER_LIST_SIZE = 6 QPACK_BLOCKED_STREAMS = 7 SETTINGS_NUM_PLACEHOLDERS = 9 class StreamType(IntEnum): CONTROL = 0 PUSH = 1 QPACK_ENCODER = 2 QPACK_DECODER = 3 class ProtocolError(Exception): """ Base class for protocol errors. These errors are not exposed to the API user, they are handled in :meth:`H3Connection.handle_event`. """ error_code = ErrorCode.HTTP_GENERAL_PROTOCOL_ERROR def __init__(self, reason_phrase: str = ""): self.reason_phrase = reason_phrase class QpackDecompressionFailed(ProtocolError): error_code = ErrorCode.HTTP_QPACK_DECOMPRESSION_FAILED class QpackDecoderStreamError(ProtocolError): error_code = ErrorCode.HTTP_QPACK_DECODER_STREAM_ERROR class QpackEncoderStreamError(ProtocolError): error_code = ErrorCode.HTTP_QPACK_ENCODER_STREAM_ERROR class StreamCreationError(ProtocolError): error_code = ErrorCode.HTTP_STREAM_CREATION_ERROR class FrameUnexpected(ProtocolError): error_code = ErrorCode.HTTP_FRAME_UNEXPECTED def encode_frame(frame_type: int, frame_data: bytes) -> bytes: frame_length = len(frame_data) buf = Buffer(capacity=frame_length + 16) buf.push_uint_var(frame_type) buf.push_uint_var(frame_length) buf.push_bytes(frame_data) return buf.data def encode_settings(settings: Dict[int, int]) -> bytes: buf = Buffer(capacity=1024) for setting, value in settings.items(): buf.push_uint_var(setting) buf.push_uint_var(value) return buf.data def parse_max_push_id(data: bytes) -> int: buf = Buffer(data=data) max_push_id = buf.pull_uint_var() assert buf.eof() return max_push_id def parse_settings(data: bytes) -> Dict[int, int]: buf = Buffer(data=data) settings = [] while not buf.eof(): setting = buf.pull_uint_var() value = buf.pull_uint_var() settings.append((setting, value)) return dict(settings) def qlog_encode_data_frame(byte_length: int, stream_id: int) -> Dict: return { "byte_length": str(byte_length), "frame": {"frame_type": "data"}, "stream_id": str(stream_id), } def qlog_encode_headers(headers: Headers) -> List[Dict]: return [ {"name": h[0].decode("utf8"), "value": h[1].decode("utf8")} for h in headers ] def qlog_encode_headers_frame( byte_length: int, headers: Headers, stream_id: int ) -> Dict: return { "byte_length": str(byte_length), "frame": {"frame_type": "headers", "headers": qlog_encode_headers(headers)}, "stream_id": str(stream_id), } def qlog_encode_push_promise_frame( byte_length: int, headers: Headers, push_id: int, stream_id: int ) -> Dict: return { "byte_length": str(byte_length), "frame": { "frame_type": "push_promise", "headers": qlog_encode_headers(headers), "push_id": str(push_id), }, "stream_id": str(stream_id), } class H3Stream: def __init__(self, stream_id: int) -> None: self.blocked = False self.blocked_frame_size: Optional[int] = None self.buffer = b"" self.ended = False self.frame_size: Optional[int] = None self.frame_type: Optional[int] = None self.headers_recv_state: HeadersState = HeadersState.INITIAL self.headers_send_state: HeadersState = HeadersState.INITIAL self.push_id: Optional[int] = None self.stream_id = stream_id self.stream_type: Optional[int] = None class H3Connection: """ A low-level HTTP/3 connection object. :param quic: A :class:`~aioquic.connection.QuicConnection` instance. """ def __init__(self, quic: QuicConnection): self._max_table_capacity = 4096 self._blocked_streams = 16 self._is_client = quic.configuration.is_client self._is_done = False self._quic = quic self._quic_logger: Optional[QuicLoggerTrace] = quic._quic_logger self._decoder = pylsqpack.Decoder( self._max_table_capacity, self._blocked_streams ) self._decoder_bytes_received = 0 self._decoder_bytes_sent = 0 self._encoder = pylsqpack.Encoder() self._encoder_bytes_received = 0 self._encoder_bytes_sent = 0 self._stream: Dict[int, H3Stream] = {} self._max_push_id: Optional[int] = 8 if self._is_client else None self._next_push_id: int = 0 self._local_control_stream_id: Optional[int] = None self._local_decoder_stream_id: Optional[int] = None self._local_encoder_stream_id: Optional[int] = None self._peer_control_stream_id: Optional[int] = None self._peer_decoder_stream_id: Optional[int] = None self._peer_encoder_stream_id: Optional[int] = None self._init_connection() def handle_event(self, event: QuicEvent) -> List[H3Event]: """ Handle a QUIC event and return a list of HTTP events. :param event: The QUIC event to handle. """ if isinstance(event, StreamDataReceived) and not self._is_done: stream_id = event.stream_id stream = self._get_or_create_stream(stream_id) try: if stream_id % 4 == 0: return self._receive_request_or_push_data( stream, event.data, event.end_stream ) elif stream_is_unidirectional(stream_id): return self._receive_stream_data_uni( stream, event.data, event.end_stream ) except ProtocolError as exc: self._is_done = True self._quic.close( error_code=exc.error_code, reason_phrase=exc.reason_phrase ) return [] def send_push_promise(self, stream_id: int, headers: Headers) -> int: """ Send a push promise related to the specified stream. Returns the stream ID on which headers and data can be sent. :param stream_id: The stream ID on which to send the data. :param headers: The HTTP request headers for this push. """ assert not self._is_client, "Only servers may send a push promise." if self._max_push_id is None or self._next_push_id >= self._max_push_id: raise NoAvailablePushIDError # send push promise push_id = self._next_push_id self._next_push_id += 1 self._quic.send_stream_data( stream_id, encode_frame( FrameType.PUSH_PROMISE, encode_uint_var(push_id) + self._encode_headers(stream_id, headers), ), ) #  create push stream push_stream_id = self._create_uni_stream(StreamType.PUSH) self._quic.send_stream_data(push_stream_id, encode_uint_var(push_id)) return push_stream_id def send_data(self, stream_id: int, data: bytes, end_stream: bool) -> None: """ Send data on the given stream. To retrieve datagram which need to be sent over the network call the QUIC connection's :meth:`~aioquic.connection.QuicConnection.datagrams_to_send` method. :param stream_id: The stream ID on which to send the data. :param data: The data to send. :param end_stream: Whether to end the stream. """ # check DATA frame is allowed stream = self._get_or_create_stream(stream_id) if stream.headers_send_state != HeadersState.AFTER_HEADERS: raise FrameUnexpected("DATA frame is not allowed in this state") # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_created", data=qlog_encode_data_frame(byte_length=len(data), stream_id=stream_id), ) self._quic.send_stream_data( stream_id, encode_frame(FrameType.DATA, data), end_stream ) def send_headers( self, stream_id: int, headers: Headers, end_stream: bool = False ) -> None: """ Send headers on the given stream. To retrieve datagram which need to be sent over the network call the QUIC connection's :meth:`~aioquic.connection.QuicConnection.datagrams_to_send` method. :param stream_id: The stream ID on which to send the headers. :param headers: The HTTP headers to send. :param end_stream: Whether to end the stream. """ # check HEADERS frame is allowed stream = self._get_or_create_stream(stream_id) if stream.headers_send_state == HeadersState.AFTER_TRAILERS: raise FrameUnexpected("HEADERS frame is not allowed in this state") frame_data = self._encode_headers(stream_id, headers) # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_created", data=qlog_encode_headers_frame( byte_length=len(frame_data), headers=headers, stream_id=stream_id ), ) # update state and send headers if stream.headers_send_state == HeadersState.INITIAL: stream.headers_send_state = HeadersState.AFTER_HEADERS else: stream.headers_send_state = HeadersState.AFTER_TRAILERS self._quic.send_stream_data( stream_id, encode_frame(FrameType.HEADERS, frame_data), end_stream ) def _create_uni_stream(self, stream_type: int) -> int: """ Create an unidirectional stream of the given type. """ stream_id = self._quic.get_next_available_stream_id(is_unidirectional=True) self._quic.send_stream_data(stream_id, encode_uint_var(stream_type)) return stream_id def _decode_headers(self, stream_id: int, frame_data: Optional[bytes]) -> Headers: """ Decode a HEADERS block and send decoder updates on the decoder stream. This is called with frame_data=None when a stream becomes unblocked. """ try: if frame_data is None: decoder, headers = self._decoder.resume_header(stream_id) else: decoder, headers = self._decoder.feed_header(stream_id, frame_data) self._decoder_bytes_sent += len(decoder) self._quic.send_stream_data(self._local_decoder_stream_id, decoder) except pylsqpack.DecompressionFailed as exc: raise QpackDecompressionFailed() from exc return headers def _encode_headers(self, stream_id: int, headers: Headers) -> bytes: """ Encode a HEADERS block and send encoder updates on the encoder stream. """ encoder, frame_data = self._encoder.encode(stream_id, headers) self._encoder_bytes_sent += len(encoder) self._quic.send_stream_data(self._local_encoder_stream_id, encoder) return frame_data def _get_or_create_stream(self, stream_id: int) -> H3Stream: if stream_id not in self._stream: self._stream[stream_id] = H3Stream(stream_id) return self._stream[stream_id] def _handle_control_frame(self, frame_type: int, frame_data: bytes) -> None: """ Handle a frame received on the peer's control stream. """ if frame_type == FrameType.SETTINGS: settings = parse_settings(frame_data) encoder = self._encoder.apply_settings( max_table_capacity=settings.get(Setting.QPACK_MAX_TABLE_CAPACITY, 0), blocked_streams=settings.get(Setting.QPACK_BLOCKED_STREAMS, 0), ) self._quic.send_stream_data(self._local_encoder_stream_id, encoder) elif frame_type == FrameType.MAX_PUSH_ID: if self._is_client: raise FrameUnexpected("Servers must not send MAX_PUSH_ID") self._max_push_id = parse_max_push_id(frame_data) elif frame_type in ( FrameType.DATA, FrameType.HEADERS, FrameType.PUSH_PROMISE, FrameType.DUPLICATE_PUSH, ): raise FrameUnexpected("Invalid frame type on control stream") def _handle_request_or_push_frame( self, frame_type: int, frame_data: Optional[bytes], stream: H3Stream, stream_ended: bool, ) -> List[H3Event]: """ Handle a frame received on a request or push stream. """ http_events: List[H3Event] = [] if frame_type == FrameType.DATA: # check DATA frame is allowed if stream.headers_recv_state != HeadersState.AFTER_HEADERS: raise FrameUnexpected("DATA frame is not allowed in this state") if stream_ended or frame_data: http_events.append( DataReceived( data=frame_data, push_id=stream.push_id, stream_ended=stream_ended, stream_id=stream.stream_id, ) ) elif frame_type == FrameType.HEADERS: # check HEADERS frame is allowed if stream.headers_recv_state == HeadersState.AFTER_TRAILERS: raise FrameUnexpected("HEADERS frame is not allowed in this state") # try to decode HEADERS, may raise pylsqpack.StreamBlocked headers = self._decode_headers(stream.stream_id, frame_data) # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_parsed", data=qlog_encode_headers_frame( byte_length=stream.blocked_frame_size if frame_data is None else len(frame_data), headers=headers, stream_id=stream.stream_id, ), ) # update state and emit headers if stream.headers_recv_state == HeadersState.INITIAL: stream.headers_recv_state = HeadersState.AFTER_HEADERS else: stream.headers_recv_state = HeadersState.AFTER_TRAILERS http_events.append( HeadersReceived( headers=headers, push_id=stream.push_id, stream_id=stream.stream_id, stream_ended=stream_ended, ) ) elif stream.frame_type == FrameType.PUSH_PROMISE and stream.push_id is None: if not self._is_client: raise FrameUnexpected("Clients must not send PUSH_PROMISE") frame_buf = Buffer(data=frame_data) push_id = frame_buf.pull_uint_var() headers = self._decode_headers( stream.stream_id, frame_data[frame_buf.tell() :] ) # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_parsed", data=qlog_encode_push_promise_frame( byte_length=len(frame_data), headers=headers, push_id=push_id, stream_id=stream.stream_id, ), ) # emit event http_events.append( PushPromiseReceived( headers=headers, push_id=push_id, stream_id=stream.stream_id ) ) elif frame_type in ( FrameType.PRIORITY, FrameType.CANCEL_PUSH, FrameType.SETTINGS, FrameType.PUSH_PROMISE, FrameType.GOAWAY, FrameType.MAX_PUSH_ID, FrameType.DUPLICATE_PUSH, ): raise FrameUnexpected( "Invalid frame type on request stream" if stream.push_id is None else "Invalid frame type on push stream" ) return http_events def _init_connection(self) -> None: # send our settings self._local_control_stream_id = self._create_uni_stream(StreamType.CONTROL) self._quic.send_stream_data( self._local_control_stream_id, encode_frame( FrameType.SETTINGS, encode_settings( { Setting.QPACK_MAX_TABLE_CAPACITY: self._max_table_capacity, Setting.QPACK_BLOCKED_STREAMS: self._blocked_streams, } ), ), ) if self._is_client and self._max_push_id is not None: self._quic.send_stream_data( self._local_control_stream_id, encode_frame(FrameType.MAX_PUSH_ID, encode_uint_var(self._max_push_id)), ) # create encoder and decoder streams self._local_encoder_stream_id = self._create_uni_stream( StreamType.QPACK_ENCODER ) self._local_decoder_stream_id = self._create_uni_stream( StreamType.QPACK_DECODER ) def _receive_request_or_push_data( self, stream: H3Stream, data: bytes, stream_ended: bool ) -> List[H3Event]: """ Handle data received on a request or push stream. """ http_events: List[H3Event] = [] stream.buffer += data if stream_ended: stream.ended = True if stream.blocked: return http_events # shortcut for DATA frame fragments if ( stream.frame_type == FrameType.DATA and stream.frame_size is not None and len(stream.buffer) < stream.frame_size ): http_events.append( DataReceived( data=stream.buffer, push_id=stream.push_id, stream_id=stream.stream_id, stream_ended=False, ) ) stream.frame_size -= len(stream.buffer) stream.buffer = b"" return http_events # handle lone FIN if stream_ended and not stream.buffer: http_events.append( DataReceived( data=b"", push_id=stream.push_id, stream_id=stream.stream_id, stream_ended=True, ) ) return http_events buf = Buffer(data=stream.buffer) consumed = 0 while not buf.eof(): # fetch next frame header if stream.frame_size is None: try: stream.frame_type = buf.pull_uint_var() stream.frame_size = buf.pull_uint_var() except BufferReadError: break consumed = buf.tell() # log frame if ( self._quic_logger is not None and stream.frame_type == FrameType.DATA ): self._quic_logger.log_event( category="http", event="frame_parsed", data=qlog_encode_data_frame( byte_length=stream.frame_size, stream_id=stream.stream_id ), ) # check how much data is available chunk_size = min(stream.frame_size, buf.capacity - consumed) if stream.frame_type != FrameType.DATA and chunk_size < stream.frame_size: break # read available data frame_data = buf.pull_bytes(chunk_size) consumed = buf.tell() # detect end of frame stream.frame_size -= chunk_size if not stream.frame_size: stream.frame_size = None try: http_events.extend( self._handle_request_or_push_frame( frame_type=stream.frame_type, frame_data=frame_data, stream=stream, stream_ended=stream.ended and buf.eof(), ) ) except pylsqpack.StreamBlocked: stream.blocked = True stream.blocked_frame_size = len(frame_data) break # remove processed data from buffer stream.buffer = stream.buffer[consumed:] return http_events def _receive_stream_data_uni( self, stream: H3Stream, data: bytes, stream_ended: bool ) -> List[H3Event]: http_events: List[H3Event] = [] stream.buffer += data if stream_ended: stream.ended = True buf = Buffer(data=stream.buffer) consumed = 0 unblocked_streams: Set[int] = set() while stream.stream_type == StreamType.PUSH or not buf.eof(): # fetch stream type for unidirectional streams if stream.stream_type is None: try: stream.stream_type = buf.pull_uint_var() except BufferReadError: break consumed = buf.tell() # check unicity if stream.stream_type == StreamType.CONTROL: if self._peer_control_stream_id is not None: raise StreamCreationError("Only one control stream is allowed") self._peer_control_stream_id = stream.stream_id elif stream.stream_type == StreamType.QPACK_DECODER: if self._peer_decoder_stream_id is not None: raise StreamCreationError( "Only one QPACK decoder stream is allowed" ) self._peer_decoder_stream_id = stream.stream_id elif stream.stream_type == StreamType.QPACK_ENCODER: if self._peer_encoder_stream_id is not None: raise StreamCreationError( "Only one QPACK encoder stream is allowed" ) self._peer_encoder_stream_id = stream.stream_id if stream.stream_type == StreamType.CONTROL: # fetch next frame try: frame_type = buf.pull_uint_var() frame_length = buf.pull_uint_var() frame_data = buf.pull_bytes(frame_length) except BufferReadError: break consumed = buf.tell() self._handle_control_frame(frame_type, frame_data) elif stream.stream_type == StreamType.PUSH: # fetch push id if stream.push_id is None: try: stream.push_id = buf.pull_uint_var() except BufferReadError: break consumed = buf.tell() # remove processed data from buffer stream.buffer = stream.buffer[consumed:] return self._receive_request_or_push_data(stream, b"", stream_ended) elif stream.stream_type == StreamType.QPACK_DECODER: # feed unframed data to decoder data = buf.pull_bytes(buf.capacity - buf.tell()) consumed = buf.tell() try: self._encoder.feed_decoder(data) except pylsqpack.DecoderStreamError as exc: raise QpackDecoderStreamError() from exc self._decoder_bytes_received += len(data) elif stream.stream_type == StreamType.QPACK_ENCODER: # feed unframed data to encoder data = buf.pull_bytes(buf.capacity - buf.tell()) consumed = buf.tell() try: unblocked_streams.update(self._decoder.feed_encoder(data)) except pylsqpack.EncoderStreamError as exc: raise QpackEncoderStreamError() from exc self._encoder_bytes_received += len(data) else: # unknown stream type, discard data buf.seek(buf.capacity) consumed = buf.tell() # remove processed data from buffer stream.buffer = stream.buffer[consumed:] # process unblocked streams for stream_id in unblocked_streams: stream = self._stream[stream_id] # resume headers http_events.extend( self._handle_request_or_push_frame( frame_type=FrameType.HEADERS, frame_data=None, stream=stream, stream_ended=stream.ended and not stream.buffer, ) ) stream.blocked = False stream.blocked_frame_size = None # resume processing if stream.buffer: http_events.extend( self._receive_request_or_push_data(stream, b"", stream.ended) ) return http_events