from __future__ import annotations import contextlib import logging import re import typing from enum import Enum, IntEnum from .._compat import UINT_VAR_MAX_SIZE from .._hazmat import ( Buffer, BufferReadError, DecoderStreamError, DecompressionFailed, EncoderStreamError, QpackDecoder, QpackEncoder, StreamBlocked, encode_uint_var, ) from ..quic.connection import QuicConnection, stream_is_unidirectional from ..quic.events import DatagramFrameReceived, QuicEvent, StreamDataReceived from ..quic.logger import QuicLoggerTrace from .events import ( DatagramReceived, DataReceived, H3Event, Headers, HeadersReceived, InformationalHeadersReceived, PushPromiseReceived, WebTransportStreamDataReceived, ) from .exceptions import NoAvailablePushIDError logger = logging.getLogger("http3") H3_ALPN = ["h3"] RESERVED_SETTINGS = (0x0, 0x2, 0x3, 0x4, 0x5) UPPERCASE = re.compile(b"[A-Z]") class ErrorCode(IntEnum): H3_NO_ERROR = 0x100 H3_GENERAL_PROTOCOL_ERROR = 0x101 H3_INTERNAL_ERROR = 0x102 H3_STREAM_CREATION_ERROR = 0x103 H3_CLOSED_CRITICAL_STREAM = 0x104 H3_FRAME_UNEXPECTED = 0x105 H3_FRAME_ERROR = 0x106 H3_EXCESSIVE_LOAD = 0x107 H3_ID_ERROR = 0x108 H3_SETTINGS_ERROR = 0x109 H3_MISSING_SETTINGS = 0x10A H3_REQUEST_REJECTED = 0x10B H3_REQUEST_CANCELLED = 0x10C H3_REQUEST_INCOMPLETE = 0x10D H3_MESSAGE_ERROR = 0x10E H3_CONNECT_ERROR = 0x10F H3_VERSION_FALLBACK = 0x110 QPACK_DECOMPRESSION_FAILED = 0x200 QPACK_ENCODER_STREAM_ERROR = 0x201 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 WEBTRANSPORT_STREAM = 0x41 class HeadersState(Enum): INITIAL = 0 AFTER_HEADERS = 1 AFTER_TRAILERS = 2 class Setting(IntEnum): QPACK_MAX_TABLE_CAPACITY = 0x1 MAX_FIELD_SECTION_SIZE = 0x6 QPACK_BLOCKED_STREAMS = 0x7 # https://datatracker.ietf.org/doc/html/rfc9220#section-5 ENABLE_CONNECT_PROTOCOL = 0x8 # https://datatracker.ietf.org/doc/html/draft-ietf-masque-h3-datagram-05#section-9.1 H3_DATAGRAM = 0xFFD277 # https://datatracker.ietf.org/doc/html/draft-ietf-webtrans-http2-02#section-10.1 ENABLE_WEBTRANSPORT = 0x2B603742 # Dummy setting to check it is correctly ignored by the peer. # https://datatracker.ietf.org/doc/html/rfc9114#section-7.2.4.1 DUMMY = 0x21 class StreamType(IntEnum): CONTROL = 0 PUSH = 1 QPACK_ENCODER = 2 QPACK_DECODER = 3 WEBTRANSPORT = 0x54 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.H3_GENERAL_PROTOCOL_ERROR def __init__(self, reason_phrase: str = ""): self.reason_phrase = reason_phrase class QpackDecompressionFailed(ProtocolError): error_code = ErrorCode.QPACK_DECOMPRESSION_FAILED class QpackDecoderStreamError(ProtocolError): error_code = ErrorCode.QPACK_DECODER_STREAM_ERROR class QpackEncoderStreamError(ProtocolError): error_code = ErrorCode.QPACK_ENCODER_STREAM_ERROR class ClosedCriticalStream(ProtocolError): error_code = ErrorCode.H3_CLOSED_CRITICAL_STREAM class FrameUnexpected(ProtocolError): error_code = ErrorCode.H3_FRAME_UNEXPECTED class MessageError(ProtocolError): error_code = ErrorCode.H3_MESSAGE_ERROR class MissingSettingsError(ProtocolError): error_code = ErrorCode.H3_MISSING_SETTINGS class SettingsError(ProtocolError): error_code = ErrorCode.H3_SETTINGS_ERROR class StreamCreationError(ProtocolError): error_code = ErrorCode.H3_STREAM_CREATION_ERROR def encode_frame(frame_type: int, frame_data: bytes) -> bytes: frame_length = len(frame_data) buf = Buffer(capacity=frame_length + 2 * UINT_VAR_MAX_SIZE) 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: dict[int, int] = {} while not buf.eof(): setting = buf.pull_uint_var() value = buf.pull_uint_var() if setting in RESERVED_SETTINGS: raise SettingsError(f"Setting identifier 0x{setting:x} is reserved") if setting in settings: raise SettingsError(f"Setting identifier 0x{setting:x} is included twice") settings[setting] = value return dict(settings) def validate_headers( headers: Headers, allowed_pseudo_headers: frozenset[bytes], required_pseudo_headers: frozenset[bytes], extract_header: bytes | None = None, ) -> bytes | None: after_pseudo_headers = False authority: bytes | None = None path: bytes | None = None scheme: bytes | None = None seen_pseudo_headers: set[bytes] = set() extracted_header_value: bytes | None = None for key, value in headers: if UPPERCASE.search(key): raise MessageError(f"Header {key!r} contains uppercase letters") if extract_header is not None and extracted_header_value is None: extracted_header_value = value if key.startswith(b":"): # pseudo-headers if after_pseudo_headers: raise MessageError( f"Pseudo-header {key!r} is not allowed after regular headers" ) if key not in allowed_pseudo_headers: raise MessageError(f"Pseudo-header {key!r} is not valid") if key in seen_pseudo_headers: raise MessageError(f"Pseudo-header {key!r} is included twice") seen_pseudo_headers.add(key) # store value if key == b":authority": authority = value elif key == b":path": path = value elif key == b":scheme": scheme = value else: # regular headers after_pseudo_headers = True # check required pseudo-headers are present missing = required_pseudo_headers.difference(seen_pseudo_headers) if missing: raise MessageError(f"Pseudo-headers {sorted(missing)} are missing") if scheme in (b"http", b"https"): if not authority: raise MessageError("Pseudo-header b':authority' cannot be empty") if not path: raise MessageError("Pseudo-header b':path' cannot be empty") return extracted_header_value def validate_push_promise_headers(headers: Headers) -> None: validate_headers( headers, allowed_pseudo_headers=frozenset( (b":method", b":scheme", b":authority", b":path") ), required_pseudo_headers=frozenset( (b":method", b":scheme", b":authority", b":path") ), ) def validate_request_headers(headers: Headers) -> None: validate_headers( headers, allowed_pseudo_headers=frozenset( # FIXME: The pseudo-header :protocol is not actually defined, but # we use it for the WebSocket demo. (b":method", b":scheme", b":authority", b":path", b":protocol") ), required_pseudo_headers=frozenset((b":method", b":authority")), ) def validate_response_headers(headers: Headers) -> int | None: status_code: bytes | None = validate_headers( headers, allowed_pseudo_headers=frozenset((b":status",)), required_pseudo_headers=frozenset((b":status",)), extract_header=b":status", ) if status_code is None: return None try: return int(status_code) except ValueError: # Defensive: return None def validate_trailers(headers: Headers) -> None: validate_headers( headers, allowed_pseudo_headers=frozenset(), required_pseudo_headers=frozenset(), ) class H3Stream: def __init__(self, stream_id: int) -> None: self.blocked = False self.blocked_frame_size: int | None = None self.buffer = b"" self.ended = False self.frame_size: int | None = None self.frame_type: int | None = None self.headers_recv_state: HeadersState = HeadersState.INITIAL self.headers_send_state: HeadersState = HeadersState.INITIAL self.push_id: int | None = None self.session_id: int | None = None self.stream_id = stream_id self.stream_type: int | None = None self.receiving_ended = False self.sending_ended = False def is_ended(self) -> bool: return self.sending_ended and self.receiving_ended and not self.blocked def finish_sending(self) -> None: if self.sending_ended: raise FrameUnexpected("stream was already ended") self.sending_ended = True class H3Connection: """ A low-level HTTP/3 connection object. :param quic: A :class:`~qh3.connection.QuicConnection` instance. """ def __init__(self, quic: QuicConnection, enable_webtransport: bool = False) -> None: # settings self._max_table_capacity = 4096 self._blocked_streams = 16 self._enable_webtransport = enable_webtransport self._is_client = quic.configuration.is_client self._is_done = False self._quic = quic self._quic_logger: QuicLoggerTrace | None = quic._quic_logger self._decoder = QpackDecoder(self._max_table_capacity, self._blocked_streams) self._decoder_bytes_received = 0 self._decoder_bytes_sent = 0 self._encoder = QpackEncoder() self._encoder_bytes_received = 0 self._encoder_bytes_sent = 0 self._settings_received = False self._stream: dict[int, H3Stream] = {} self._max_push_id: int | None = 8 if self._is_client else None self._next_push_id: int = 0 self._local_control_stream_id: int | None = None self._local_decoder_stream_id: int | None = None self._local_encoder_stream_id: int | None = None self._peer_control_stream_id: int | None = None self._peer_decoder_stream_id: int | None = None self._peer_encoder_stream_id: int | None = None self._received_settings: dict[int, int] | None = None self._sent_settings: dict[int, int] | None = None self._blocked_stream_map: dict[int, H3Stream] = {} self._init_connection() def create_webtransport_stream( self, session_id: int, is_unidirectional: bool = False ) -> int: """ Create a WebTransport stream and return the stream ID. :param session_id: The WebTransport session identifier. :param is_unidirectional: Whether to create a unidirectional stream. """ if is_unidirectional: stream_id = self._create_uni_stream(StreamType.WEBTRANSPORT) self._quic.send_stream_data(stream_id, encode_uint_var(session_id)) else: stream_id = self._quic.get_next_available_stream_id() self._log_stream_type( stream_id=stream_id, stream_type=StreamType.WEBTRANSPORT ) self._quic.send_stream_data( stream_id, encode_uint_var(FrameType.WEBTRANSPORT_STREAM) + encode_uint_var(session_id), ) return stream_id 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 not self._is_done: try: if isinstance(event, StreamDataReceived): return self._receive_stream_data(event) elif isinstance(event, DatagramFrameReceived): return self._receive_datagram(event.data) except ProtocolError as exc: self._is_done = True self._quic.close( error_code=exc.error_code, reason_phrase=exc.reason_phrase ) return [] def send_datagram(self, flow_id: int, data: bytes) -> None: """ Send a datagram for the specified flow. :param flow_id: The flow ID. :param data: The HTTP/3 datagram payload. """ self._quic.send_datagram_frame(encode_uint_var(flow_id) + data) 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, push_id=push_id) 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:`~qh3.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 with self._get_or_create_stream(stream_id) as stream: if stream.headers_send_state != HeadersState.AFTER_HEADERS: raise FrameUnexpected("DATA frame is not allowed in this state") if end_stream: stream.finish_sending() # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_created", data=self._quic_logger.encode_http3_data_frame( 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:`~qh3.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 with self._get_or_create_stream(stream_id) as stream: if stream.headers_send_state == HeadersState.AFTER_TRAILERS: raise FrameUnexpected("HEADERS frame is not allowed in this state") if end_stream: stream.finish_sending() 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=self._quic_logger.encode_http3_headers_frame( length=len(frame_data), headers=headers, stream_id=stream_id ), ) # update state and send headers if stream.headers_send_state == HeadersState.INITIAL: is_informational_headers = False if not self._is_client and not end_stream: for k, v in headers: if k == b":status": if int(v) < 200: is_informational_headers = True break elif not k.startswith(b":"): break # only the server is allowed to do so! if not is_informational_headers: 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 ) @property def received_settings(self) -> dict[int, int] | None: """ Return the received SETTINGS frame, or None. """ return self._received_settings @property def sent_settings(self) -> dict[int, int] | None: """ Return the sent SETTINGS frame, or None. """ return self._sent_settings def _create_uni_stream(self, stream_type: int, push_id: int | None = None) -> int: """ Create an unidirectional stream of the given type. """ stream_id = self._quic.get_next_available_stream_id(is_unidirectional=True) self._log_stream_type( push_id=push_id, stream_id=stream_id, stream_type=stream_type ) self._quic.send_stream_data(stream_id, encode_uint_var(stream_type)) return stream_id def _decode_headers(self, stream_id: int, frame_data: bytes | None) -> 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._blocked_stream_map[stream_id]._pending # type: ignore[attr-defined] del self._blocked_stream_map[stream_id]._pending # type: ignore[attr-defined] else: # todo: investigate why the underlying implementation # seems to ignore bad frames.. if not frame_data: raise DecompressionFailed() 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 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. """ try: encoder, frame_data = self._encoder.encode(stream_id, headers) except EncoderStreamError as exc: raise QpackEncoderStreamError() from exc self._encoder_bytes_sent += len(encoder) self._quic.send_stream_data(self._local_encoder_stream_id, encoder) return frame_data @contextlib.contextmanager def _get_or_create_stream(self, stream_id: int) -> typing.Generator[H3Stream]: if stream_id not in self._stream: self._stream[stream_id] = H3Stream(stream_id) stream = self._stream[stream_id] try: yield stream finally: # Don't forget to delete stream objects when they are done if stream.is_ended(): del self._stream[stream_id] def _get_local_settings(self) -> dict[int, int]: """ Return the local HTTP/3 settings. """ settings: dict[int, int] = { Setting.QPACK_MAX_TABLE_CAPACITY: self._max_table_capacity, Setting.QPACK_BLOCKED_STREAMS: self._blocked_streams, Setting.ENABLE_CONNECT_PROTOCOL: 1, Setting.DUMMY: 1, } if self._enable_webtransport: settings[Setting.H3_DATAGRAM] = 1 settings[Setting.ENABLE_WEBTRANSPORT] = 1 return settings 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 and not self._settings_received: raise MissingSettingsError if frame_type == FrameType.SETTINGS: if self._settings_received: raise FrameUnexpected("SETTINGS have already been received") settings = parse_settings(frame_data) self._validate_settings(settings) self._received_settings = settings encoder = self._encoder.apply_settings( max_table_capacity=settings.get(Setting.QPACK_MAX_TABLE_CAPACITY, 0), dyn_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) self._settings_received = True 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: bytes | None, 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) status_code: int | None = None # validate headers if stream.headers_recv_state == HeadersState.INITIAL: if self._is_client: status_code = validate_response_headers(headers) else: validate_request_headers(headers) else: validate_trailers(headers) # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_parsed", data=self._quic_logger.encode_http3_headers_frame( 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: # Informational Response MUST be taken as-is without # skipping the main response. if status_code is None or status_code >= 200 or stream_ended: stream.headers_recv_state = HeadersState.AFTER_HEADERS else: stream.headers_recv_state = HeadersState.AFTER_TRAILERS if ( stream.headers_recv_state == HeadersState.INITIAL and status_code is not None and status_code < 200 ): http_events.append( InformationalHeadersReceived( headers=headers, stream_id=stream.stream_id, ) ) else: http_events.append( HeadersReceived( headers=headers, push_id=stream.push_id, stream_id=stream.stream_id, stream_ended=stream_ended, ) ) elif 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() :] ) # validate headers validate_push_promise_headers(headers) # log frame if self._quic_logger is not None: self._quic_logger.log_event( category="http", event="frame_parsed", data=self._quic_logger.encode_http3_push_promise_frame( 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._sent_settings = self._get_local_settings() self._quic.send_stream_data( self._local_control_stream_id, encode_frame(FrameType.SETTINGS, encode_settings(self._sent_settings)), ) 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 _log_stream_type( self, stream_id: int, stream_type: int, push_id: int | None = None ) -> None: if self._quic_logger is not None: type_name = { 0: "control", 1: "push", 2: "qpack_encoder", 3: "qpack_decoder", 0x54: "webtransport", # NOTE: not standardized yet }.get(stream_type, "unknown") data = {"new": type_name, "stream_id": stream_id} if push_id is not None: data["associated_push_id"] = push_id self._quic_logger.log_event( category="http", event="stream_type_set", data=data, ) def _receive_datagram(self, data: bytes) -> list[H3Event]: """ Handle a datagram. """ buf = Buffer(data=data) try: flow_id = buf.pull_uint_var() except BufferReadError: raise ProtocolError("Could not parse flow ID") return [DatagramReceived(data=data[buf.tell() :], flow_id=flow_id)] def _receive_stream_data(self, event: StreamDataReceived) -> list[H3Event]: stream_id = event.stream_id with self._get_or_create_stream(stream_id) as stream: if stream_is_unidirectional(stream_id): return self._receive_stream_data_uni( stream, event.data, event.end_stream ) else: return self._receive_request_or_push_data( stream, event.data, event.end_stream ) 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.receiving_ended = True if stream.blocked: return http_events # shortcut for WEBTRANSPORT_STREAM frame fragments if ( stream.frame_type == FrameType.WEBTRANSPORT_STREAM and stream.session_id is not None ): http_events.append( WebTransportStreamDataReceived( data=stream.buffer, session_id=stream.session_id, stream_id=stream.stream_id, stream_ended=stream_ended, ) ) stream.buffer = b"" 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() # WEBTRANSPORT_STREAM frames last until the end of the stream if stream.frame_type == FrameType.WEBTRANSPORT_STREAM: stream.session_id = stream.frame_size stream.frame_size = None frame_data = stream.buffer[consumed:] stream.buffer = b"" self._log_stream_type( stream_id=stream.stream_id, stream_type=StreamType.WEBTRANSPORT ) if frame_data or stream_ended: http_events.append( WebTransportStreamDataReceived( data=frame_data, session_id=stream.session_id, stream_id=stream.stream_id, stream_ended=stream_ended, ) ) return http_events # 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=self._quic_logger.encode_http3_data_frame( 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) frame_type = stream.frame_type consumed = buf.tell() # detect end of frame stream.frame_size -= chunk_size if not stream.frame_size: stream.frame_size = None stream.frame_type = None try: http_events.extend( self._handle_request_or_push_frame( frame_type=frame_type, frame_data=frame_data, stream=stream, stream_ended=stream.receiving_ended and buf.eof(), ) ) except StreamBlocked: stream.blocked = True stream.blocked_frame_size = len(frame_data) self._blocked_stream_map[stream.stream_id] = stream 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.receiving_ended = True buf = Buffer(data=stream.buffer) consumed = 0 unblocked_streams: set[int] = set() while ( stream.stream_type in (StreamType.PUSH, StreamType.CONTROL, StreamType.WEBTRANSPORT) 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 # for PUSH, logging is performed once the push_id is known if stream.stream_type != StreamType.PUSH: self._log_stream_type( stream_id=stream.stream_id, stream_type=stream.stream_type ) if stream.stream_type == StreamType.CONTROL: if stream_ended: raise ClosedCriticalStream("Closing control stream is not allowed") # 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() self._log_stream_type( push_id=stream.push_id, stream_id=stream.stream_id, stream_type=stream.stream_type, ) # 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.WEBTRANSPORT: # fetch session id if stream.session_id is None: try: stream.session_id = buf.pull_uint_var() except BufferReadError: break consumed = buf.tell() frame_data = stream.buffer[consumed:] stream.buffer = b"" if frame_data or stream_ended: http_events.append( WebTransportStreamDataReceived( data=frame_data, session_id=stream.session_id, stream_ended=stream.receiving_ended, stream_id=stream.stream_id, ) ) return http_events 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 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: self._decoder.feed_encoder(data) except EncoderStreamError as exc: raise QpackEncoderStreamError() from exc for blocked_id, blocked_stream in self._blocked_stream_map.items(): try: stream_data, headers = self._decoder.resume_header(blocked_id) blocked_stream._pending = ( # type: ignore[attr-defined] stream_data, headers, ) unblocked_streams.add(blocked_id) except StreamBlocked: continue 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.receiving_ended and not stream.buffer, ) ) stream.blocked = False stream.blocked_frame_size = None del self._blocked_stream_map[stream_id] # resume processing if stream.buffer: http_events.extend( self._receive_request_or_push_data( stream, b"", stream.receiving_ended, ) ) return http_events def _validate_settings(self, settings: dict[int, int]) -> None: for setting in [ Setting.ENABLE_CONNECT_PROTOCOL, Setting.ENABLE_WEBTRANSPORT, Setting.H3_DATAGRAM, ]: if setting in settings and settings[setting] not in (0, 1): raise SettingsError(f"{setting.name} setting must be 0 or 1") if ( settings.get(Setting.H3_DATAGRAM) == 1 and self._quic._remote_max_datagram_frame_size is None ): raise SettingsError( "H3_DATAGRAM requires max_datagram_frame_size transport parameter" ) if ( settings.get(Setting.ENABLE_WEBTRANSPORT) == 1 and settings.get(Setting.H3_DATAGRAM) != 1 ): raise SettingsError("ENABLE_WEBTRANSPORT requires H3_DATAGRAM")