blob: c3fbab2987167f6bf07523b4a06c6737decfab78 [file] [log] [blame]
#include <cstdint>
#include <limits>
#include <list>
#include <memory>
#include <vector>
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "absl/types/variant.h"
#include "http2/adapter/data_source.h"
#include "http2/adapter/event_forwarder.h"
#include "http2/adapter/header_validator.h"
#include "http2/adapter/http2_protocol.h"
#include "http2/adapter/http2_session.h"
#include "http2/adapter/http2_util.h"
#include "http2/adapter/http2_visitor_interface.h"
#include "http2/adapter/window_manager.h"
#include "http2/core/http2_trace_logging.h"
#include "http2/core/priority_write_scheduler.h"
#include "common/platform/api/quiche_bug_tracker.h"
#include "common/platform/api/quiche_export.h"
#include "spdy/core/http2_frame_decoder_adapter.h"
#include "spdy/core/no_op_headers_handler.h"
#include "spdy/core/spdy_framer.h"
#include "spdy/core/spdy_header_block.h"
#include "spdy/core/spdy_protocol.h"
namespace http2 {
namespace adapter {
// This class manages state associated with a single multiplexed HTTP/2 session.
: public Http2Session,
public spdy::SpdyFramerVisitorInterface,
public spdy::ExtensionVisitorInterface {
Perspective perspective = Perspective::kClient;
// The maximum HPACK table size to use.
absl::optional<size_t> max_hpack_encoding_table_capacity = absl::nullopt;
// The maximum number of decoded header bytes that a stream can receive.
absl::optional<uint32_t> max_header_list_bytes = absl::nullopt;
// Whether to automatically send PING acks when receiving a PING.
bool auto_ping_ack = true;
// Whether (as server) to send a RST_STREAM NO_ERROR when sending a fin on
// an incomplete stream.
bool rst_stream_no_error_when_incomplete = false;
// Whether (as server) to queue trailers until after a stream's data source
// has indicated the end of data. If false, the server will assume that
// submitting trailers indicates the end of data.
bool trailers_require_end_data = false;
OgHttp2Session(Http2VisitorInterface& visitor, Options options);
~OgHttp2Session() override;
// Enqueues a frame for transmission to the peer.
void EnqueueFrame(std::unique_ptr<spdy::SpdyFrameIR> frame);
// Starts a graceful shutdown sequence. No-op if a GOAWAY has already been
// sent.
void StartGracefulShutdown();
// Invokes the visitor's OnReadyToSend() method for serialized frames and
// DataFrameSource::Send() for data frames.
int Send();
int32_t SubmitRequest(absl::Span<const Header> headers,
std::unique_ptr<DataFrameSource> data_source,
void* user_data);
int SubmitResponse(Http2StreamId stream_id, absl::Span<const Header> headers,
std::unique_ptr<DataFrameSource> data_source);
int SubmitTrailer(Http2StreamId stream_id, absl::Span<const Header> trailers);
void SubmitMetadata(Http2StreamId stream_id,
std::unique_ptr<MetadataSource> source);
void SubmitSettings(absl::Span<const Http2Setting> settings);
bool IsServerSession() const {
return options_.perspective == Perspective::kServer;
Http2StreamId GetHighestReceivedStreamId() const {
return highest_received_stream_id_;
void SetStreamUserData(Http2StreamId stream_id, void* user_data);
void* GetStreamUserData(Http2StreamId stream_id);
// Resumes a stream that was previously blocked. Returns true on success.
bool ResumeStream(Http2StreamId stream_id);
// Returns the peer's outstanding stream receive window for the given stream.
int GetStreamSendWindowSize(Http2StreamId stream_id) const;
// Returns the current upper bound on the flow control receive window for this
// stream.
int GetStreamReceiveWindowLimit(Http2StreamId stream_id) const;
// Returns the outstanding stream receive window, or -1 if the stream does not
// exist.
int GetStreamReceiveWindowSize(Http2StreamId stream_id) const;
// Returns the outstanding connection receive window.
int GetReceiveWindowSize() const;
// Returns the size of the HPACK encoder's dynamic table, including the
// per-entry overhead from the specification.
int GetHpackEncoderDynamicTableSize() const;
// Returns the maximum capacity of the HPACK encoder's dynamic table.
int GetHpackEncoderDynamicTableCapacity() const;
// Returns the size of the HPACK decoder's dynamic table, including the
// per-entry overhead from the specification.
int GetHpackDecoderDynamicTableSize() const;
// Returns the size of the HPACK decoder's most recently applied size limit.
int GetHpackDecoderSizeLimit() const;
// From Http2Session.
int64_t ProcessBytes(absl::string_view bytes) override;
int Consume(Http2StreamId stream_id, size_t num_bytes) override;
bool want_read() const override {
return !received_goaway_ && !decoder_.HasError();
bool want_write() const override {
return !fatal_send_error_ &&
(!frames_.empty() || !buffered_data_.empty() ||
!connection_metadata_.empty() || HasReadyStream());
int GetRemoteWindowSize() const override { return connection_send_window_; }
// From SpdyFramerVisitorInterface
void OnError(http2::Http2DecoderAdapter::SpdyFramerError error,
std::string detailed_error) override;
void OnCommonHeader(spdy::SpdyStreamId /*stream_id*/,
size_t /*length*/,
uint8_t /*type*/,
uint8_t /*flags*/) override;
void OnDataFrameHeader(spdy::SpdyStreamId stream_id,
size_t length,
bool fin) override;
void OnStreamFrameData(spdy::SpdyStreamId stream_id,
const char* data,
size_t len) override;
void OnStreamEnd(spdy::SpdyStreamId stream_id) override;
void OnStreamPadLength(spdy::SpdyStreamId /*stream_id*/,
size_t /*value*/) override;
void OnStreamPadding(spdy::SpdyStreamId stream_id, size_t len) override;
spdy::SpdyHeadersHandlerInterface* OnHeaderFrameStart(
spdy::SpdyStreamId stream_id) override;
void OnHeaderFrameEnd(spdy::SpdyStreamId stream_id) override;
void OnRstStream(spdy::SpdyStreamId stream_id,
spdy::SpdyErrorCode error_code) override;
void OnSettings() override;
void OnSetting(spdy::SpdySettingsId id, uint32_t value) override;
void OnSettingsEnd() override;
void OnSettingsAck() override;
void OnPing(spdy::SpdyPingId unique_id, bool is_ack) override;
void OnGoAway(spdy::SpdyStreamId last_accepted_stream_id,
spdy::SpdyErrorCode error_code) override;
bool OnGoAwayFrameData(const char* goaway_data, size_t len) override;
void OnHeaders(spdy::SpdyStreamId stream_id,
bool has_priority,
int weight,
spdy::SpdyStreamId parent_stream_id,
bool exclusive,
bool fin,
bool end) override;
void OnWindowUpdate(spdy::SpdyStreamId stream_id,
int delta_window_size) override;
void OnPushPromise(spdy::SpdyStreamId stream_id,
spdy::SpdyStreamId promised_stream_id,
bool end) override;
void OnContinuation(spdy::SpdyStreamId stream_id, bool end) override;
void OnAltSvc(spdy::SpdyStreamId /*stream_id*/, absl::string_view /*origin*/,
const spdy::SpdyAltSvcWireFormat::
AlternativeServiceVector& /*altsvc_vector*/) override;
void OnPriority(spdy::SpdyStreamId stream_id,
spdy::SpdyStreamId parent_stream_id,
int weight,
bool exclusive) override;
void OnPriorityUpdate(spdy::SpdyStreamId prioritized_stream_id,
absl::string_view priority_field_value) override;
bool OnUnknownFrame(spdy::SpdyStreamId stream_id,
uint8_t frame_type) override;
// Invoked when header processing encounters an invalid or otherwise
// problematic header.
void OnHeaderStatus(Http2StreamId stream_id,
Http2VisitorInterface::OnHeaderResult result);
// Returns true if a recognized extension frame is received.
bool OnFrameHeader(spdy::SpdyStreamId stream_id, size_t length, uint8_t type,
uint8_t flags) override;
// Handles the payload for a recognized extension frame.
void OnFramePayload(const char* data, size_t len) override;
using MetadataSequence = std::vector<std::unique_ptr<MetadataSource>>;
struct QUICHE_EXPORT_PRIVATE StreamState {
StreamState(int32_t stream_receive_window,
WindowManager::WindowUpdateListener listener)
: window_manager(stream_receive_window, std::move(listener)) {}
WindowManager window_manager;
std::unique_ptr<DataFrameSource> outbound_body;
MetadataSequence outbound_metadata;
std::unique_ptr<spdy::SpdyHeaderBlock> trailers;
void* user_data = nullptr;
int32_t send_window = kInitialFlowControlWindowSize;
absl::optional<HeaderType> received_header_type;
bool half_closed_local = false;
bool half_closed_remote = false;
// Indicates that `outbound_body` temporarily cannot produce data.
bool data_deferred = false;
using StreamStateMap = absl::flat_hash_map<Http2StreamId, StreamState>;
struct QUICHE_EXPORT_PRIVATE PendingStreamState {
Http2StreamId stream_id;
spdy::SpdyHeaderBlock headers;
std::unique_ptr<DataFrameSource> data_source;
void* user_data = nullptr;
class QUICHE_EXPORT_PRIVATE PassthroughHeadersHandler
: public spdy::SpdyHeadersHandlerInterface {
explicit PassthroughHeadersHandler(OgHttp2Session& session,
Http2VisitorInterface& visitor)
: session_(session), visitor_(visitor) {}
void set_stream_id(Http2StreamId stream_id) {
stream_id_ = stream_id;
result_ = Http2VisitorInterface::HEADER_OK;
void set_frame_contains_fin() { frame_contains_fin_ = true; }
void set_header_type(HeaderType type) { type_ = type; }
HeaderType header_type() const { return type_; }
void OnHeaderBlockStart() override;
void OnHeader(absl::string_view key, absl::string_view value) override;
void OnHeaderBlockEnd(size_t /* uncompressed_header_bytes */,
size_t /* compressed_header_bytes */) override;
absl::string_view status_header() {
QUICHE_DCHECK(type_ == HeaderType::RESPONSE ||
type_ == HeaderType::RESPONSE_100);
return validator_.status_header();
void AllowConnect() { validator_.AllowConnect(); }
OgHttp2Session& session_;
Http2VisitorInterface& visitor_;
Http2StreamId stream_id_ = 0;
Http2VisitorInterface::OnHeaderResult result_ =
// Validates header blocks according to the HTTP/2 specification.
HeaderValidator validator_;
HeaderType type_ = HeaderType::RESPONSE;
bool frame_contains_fin_ = false;
struct QUICHE_EXPORT_PRIVATE ProcessBytesResultVisitor;
// Queues the connection preface, if not already done.
void MaybeSetupPreface();
// Gets the settings to be sent in the initial SETTINGS frame sent as part of
// the connection preface.
std::vector<Http2Setting> GetInitialSettings() const;
// Prepares and returns a SETTINGS frame with the given `settings`.
std::unique_ptr<spdy::SpdySettingsIR> PrepareSettingsFrame(
absl::Span<const Http2Setting> settings);
void SendWindowUpdate(Http2StreamId stream_id, size_t update_delta);
enum class SendResult {
// All data was flushed.
// Not all data was flushed (due to flow control or TCP back pressure).
// An error occurred while sending data.
enum class ProcessBytesError {
// A general, unspecified error.
using ProcessBytesResult = absl::variant<int64_t, ProcessBytesError>;
// Attempts to process `bytes` and returns the number of bytes proccessed on
// success or the processing error on failure.
ProcessBytesResult ProcessBytesImpl(absl::string_view bytes);
// Returns true if at least one stream has data or control frames to write.
bool HasReadyStream() const;
// Returns the next stream that has something to write. If there are no such
// streams, returns zero.
Http2StreamId GetNextReadyStream();
// Sends the buffered connection preface or serialized frame data, if any.
SendResult MaybeSendBufferedData();
// Serializes and sends queued frames.
SendResult SendQueuedFrames();
// Returns false if a fatal connection error occurred.
bool AfterFrameSent(uint8_t frame_type, uint32_t stream_id,
size_t payload_length, uint8_t flags,
uint32_t error_code);
// Writes DATA frames for stream `stream_id`.
SendResult WriteForStream(Http2StreamId stream_id);
SendResult SendMetadata(Http2StreamId stream_id, MetadataSequence& sequence);
void SendHeaders(Http2StreamId stream_id, spdy::SpdyHeaderBlock headers,
bool end_stream);
void SendTrailers(Http2StreamId stream_id, spdy::SpdyHeaderBlock trailers);
// Encapsulates the RST_STREAM NO_ERROR behavior described in RFC 7540
// Section 8.1.
void MaybeFinWithRstStream(StreamStateMap::iterator iter);
// Performs flow control accounting for data sent by the peer.
void MarkDataBuffered(Http2StreamId stream_id, size_t bytes);
// Creates a stream for `stream_id` if not already present and returns an
// iterator pointing to it.
StreamStateMap::iterator CreateStream(Http2StreamId stream_id);
// Creates a stream for `stream_id`, stores the `data_source` and `user_data`
// in the stream state, and sends the `headers`.
void StartRequest(Http2StreamId stream_id, spdy::SpdyHeaderBlock headers,
std::unique_ptr<DataFrameSource> data_source,
void* user_data);
// Closes the given `stream_id` with the given `error_code`.
void CloseStream(Http2StreamId stream_id, Http2ErrorCode error_code);
// Calculates the next expected header type for a stream in a given state.
HeaderType NextHeaderType(absl::optional<HeaderType> current_type);
// Returns true if the session can create a new stream.
bool CanCreateStream() const;
// Informs the visitor of the connection `error` and stops processing on the
// connection. If server-side, also sends a GOAWAY with `error_code`.
void LatchErrorAndNotify(Http2ErrorCode error_code,
Http2VisitorInterface::ConnectionError error);
void CloseStreamIfReady(uint8_t frame_type, uint32_t stream_id);
// Receives events when inbound frames are parsed.
Http2VisitorInterface& visitor_;
// Forwards received events to the session if it can accept them.
EventForwarder event_forwarder_;
// Logs received frames when enabled.
Http2TraceLogger receive_logger_;
// Logs sent frames when enabled.
Http2FrameLogger send_logger_;
// Encodes outbound frames.
spdy::SpdyFramer framer_{spdy::SpdyFramer::ENABLE_COMPRESSION};
// Decodes inbound frames.
http2::Http2DecoderAdapter decoder_;
// Maintains the state of active streams known to this session.
StreamStateMap stream_map_;
// Maintains the state of pending streams known to this session. A pending
// stream is kept in this list until it can be created while complying with
// `max_outbound_concurrent_streams_`.
std::list<PendingStreamState> pending_streams_;
// The queue of outbound frames.
std::list<std::unique_ptr<spdy::SpdyFrameIR>> frames_;
// Buffered data (connection preface, serialized frames) that has not yet been
// sent.
std::string buffered_data_;
// Maintains the set of streams ready to write data to the peer.
using WriteScheduler = PriorityWriteScheduler<Http2StreamId>;
WriteScheduler write_scheduler_;
// Stores the queue of callbacks to invoke upon receiving SETTINGS acks. At
// most one callback is invoked for each SETTINGS ack.
using SettingsAckCallback = std::function<void()>;
std::list<SettingsAckCallback> settings_ack_callbacks_;
// Delivers header name-value pairs to the visitor.
PassthroughHeadersHandler headers_handler_;
// Ignores header data, e.g., for an unknown or rejected stream.
spdy::NoOpHeadersHandler noop_headers_handler_;
// Tracks the remaining client connection preface, in the case of a server
// session.
absl::string_view remaining_preface_;
WindowManager connection_window_manager_;
absl::flat_hash_set<Http2StreamId> streams_reset_;
// The number of frames currently queued per stream.
absl::flat_hash_map<Http2StreamId, int> queued_frames_;
// Includes streams that are currently ready to write trailers.
absl::flat_hash_set<Http2StreamId> trailers_ready_;
// Includes streams that are currently ready to write metadata.
absl::flat_hash_set<Http2StreamId> metadata_ready_;
MetadataSequence connection_metadata_;
Http2StreamId next_stream_id_ = 1;
// The highest received stream ID is the highest stream ID in any frame read
// from the peer. The highest processed stream ID is the highest stream ID for
// which this endpoint created a stream in the stream map.
Http2StreamId highest_received_stream_id_ = 0;
Http2StreamId highest_processed_stream_id_ = 0;
Http2StreamId metadata_stream_id_ = 0;
size_t metadata_length_ = 0;
int32_t connection_send_window_ = kInitialFlowControlWindowSize;
// The initial flow control receive window size for any newly created streams.
int32_t stream_receive_window_limit_ = kInitialFlowControlWindowSize;
uint32_t max_frame_payload_ = 16384u;
// The maximum number of concurrent streams that this connection can open to
// its peer and allow from its peer, respectively. Although the initial value
// is unlimited, the spec encourages a value of at least 100. We limit
// ourselves to opening 100 until told otherwise by the peer and allow an
// unlimited number from the peer until updated from SETTINGS we send.
uint32_t max_outbound_concurrent_streams_ = 100u;
uint32_t pending_max_inbound_concurrent_streams_ =
uint32_t max_inbound_concurrent_streams_ =
Options options_;
// The HPACK encoder header table capacity that will be applied when
// acking SETTINGS from the peer. Only contains a value if the peer advertises
// a larger table capacity than currently used; a smaller value can safely be
// applied immediately upon receipt.
absl::optional<uint32_t> encoder_header_table_capacity_when_acking_;
bool received_goaway_ = false;
bool queued_preface_ = false;
bool peer_supports_metadata_ = false;
bool end_metadata_ = false;
// Recursion guard for ProcessBytes().
bool processing_bytes_ = false;
// Recursion guard for Send().
bool sending_ = false;
// Replace this with a stream ID, for multiple GOAWAY support.
bool queued_goaway_ = false;
bool latched_error_ = false;
// True if a fatal sending error has occurred.
bool fatal_send_error_ = false;
} // namespace adapter
} // namespace http2