| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "quiche/http2/decoder/payload_decoders/push_promise_payload_decoder.h" |
| |
| #include <stddef.h> |
| |
| #include <ostream> |
| |
| #include "absl/base/macros.h" |
| #include "quiche/http2/decoder/decode_buffer.h" |
| #include "quiche/http2/decoder/http2_frame_decoder_listener.h" |
| #include "quiche/http2/http2_constants.h" |
| #include "quiche/http2/http2_structures.h" |
| #include "quiche/common/platform/api/quiche_bug_tracker.h" |
| #include "quiche/common/platform/api/quiche_logging.h" |
| |
| namespace http2 { |
| |
| std::ostream& operator<<(std::ostream& out, |
| PushPromisePayloadDecoder::PayloadState v) { |
| switch (v) { |
| case PushPromisePayloadDecoder::PayloadState::kReadPadLength: |
| return out << "kReadPadLength"; |
| case PushPromisePayloadDecoder::PayloadState:: |
| kStartDecodingPushPromiseFields: |
| return out << "kStartDecodingPushPromiseFields"; |
| case PushPromisePayloadDecoder::PayloadState::kReadPayload: |
| return out << "kReadPayload"; |
| case PushPromisePayloadDecoder::PayloadState::kSkipPadding: |
| return out << "kSkipPadding"; |
| case PushPromisePayloadDecoder::PayloadState:: |
| kResumeDecodingPushPromiseFields: |
| return out << "kResumeDecodingPushPromiseFields"; |
| } |
| return out << static_cast<int>(v); |
| } |
| |
| DecodeStatus PushPromisePayloadDecoder::StartDecodingPayload( |
| FrameDecoderState* state, DecodeBuffer* db) { |
| const Http2FrameHeader& frame_header = state->frame_header(); |
| const uint32_t total_length = frame_header.payload_length; |
| |
| QUICHE_DVLOG(2) << "PushPromisePayloadDecoder::StartDecodingPayload: " |
| << frame_header; |
| |
| QUICHE_DCHECK_EQ(Http2FrameType::PUSH_PROMISE, frame_header.type); |
| QUICHE_DCHECK_LE(db->Remaining(), total_length); |
| QUICHE_DCHECK_EQ(0, frame_header.flags & ~(Http2FrameFlag::END_HEADERS | |
| Http2FrameFlag::PADDED)); |
| |
| if (!frame_header.IsPadded()) { |
| // If it turns out that PUSH_PROMISE frames without padding are sufficiently |
| // common, and that they are usually short enough that they fit entirely |
| // into one DecodeBuffer, we can detect that here and implement a special |
| // case, avoiding the state machine in ResumeDecodingPayload. |
| payload_state_ = PayloadState::kStartDecodingPushPromiseFields; |
| } else { |
| payload_state_ = PayloadState::kReadPadLength; |
| } |
| state->InitializeRemainders(); |
| return ResumeDecodingPayload(state, db); |
| } |
| |
| DecodeStatus PushPromisePayloadDecoder::ResumeDecodingPayload( |
| FrameDecoderState* state, DecodeBuffer* db) { |
| QUICHE_DVLOG(2) << "UnknownPayloadDecoder::ResumeDecodingPayload" |
| << " remaining_payload=" << state->remaining_payload() |
| << " db->Remaining=" << db->Remaining(); |
| |
| const Http2FrameHeader& frame_header = state->frame_header(); |
| QUICHE_DCHECK_EQ(Http2FrameType::PUSH_PROMISE, frame_header.type); |
| QUICHE_DCHECK_LE(state->remaining_payload(), frame_header.payload_length); |
| QUICHE_DCHECK_LE(db->Remaining(), frame_header.payload_length); |
| |
| DecodeStatus status; |
| while (true) { |
| QUICHE_DVLOG(2) |
| << "PushPromisePayloadDecoder::ResumeDecodingPayload payload_state_=" |
| << payload_state_; |
| switch (payload_state_) { |
| case PayloadState::kReadPadLength: |
| QUICHE_DCHECK_EQ(state->remaining_payload(), |
| frame_header.payload_length); |
| // ReadPadLength handles the OnPadLength callback, and updating the |
| // remaining_payload and remaining_padding fields. If the amount of |
| // padding is too large to fit in the frame's payload, ReadPadLength |
| // instead calls OnPaddingTooLong and returns kDecodeError. |
| // Suppress the call to OnPadLength because we haven't yet called |
| // OnPushPromiseStart, which needs to wait until we've decoded the |
| // Promised Stream ID. |
| status = state->ReadPadLength(db, /*report_pad_length*/ false); |
| if (status != DecodeStatus::kDecodeDone) { |
| payload_state_ = PayloadState::kReadPadLength; |
| return status; |
| } |
| ABSL_FALLTHROUGH_INTENDED; |
| |
| case PayloadState::kStartDecodingPushPromiseFields: |
| status = |
| state->StartDecodingStructureInPayload(&push_promise_fields_, db); |
| if (status != DecodeStatus::kDecodeDone) { |
| payload_state_ = PayloadState::kResumeDecodingPushPromiseFields; |
| return status; |
| } |
| // Finished decoding the Promised Stream ID. Can now tell the listener |
| // that we're starting to decode a PUSH_PROMISE frame. |
| ReportPushPromise(state); |
| ABSL_FALLTHROUGH_INTENDED; |
| |
| case PayloadState::kReadPayload: |
| QUICHE_DCHECK_LT(state->remaining_payload(), |
| frame_header.payload_length); |
| QUICHE_DCHECK_LE(state->remaining_payload(), |
| frame_header.payload_length - |
| Http2PushPromiseFields::EncodedSize()); |
| QUICHE_DCHECK_LE( |
| state->remaining_payload(), |
| frame_header.payload_length - |
| Http2PushPromiseFields::EncodedSize() - |
| (frame_header.IsPadded() ? (1 + state->remaining_padding()) |
| : 0)); |
| { |
| size_t avail = state->AvailablePayload(db); |
| state->listener()->OnHpackFragment(db->cursor(), avail); |
| db->AdvanceCursor(avail); |
| state->ConsumePayload(avail); |
| } |
| if (state->remaining_payload() > 0) { |
| payload_state_ = PayloadState::kReadPayload; |
| return DecodeStatus::kDecodeInProgress; |
| } |
| ABSL_FALLTHROUGH_INTENDED; |
| |
| case PayloadState::kSkipPadding: |
| // SkipPadding handles the OnPadding callback. |
| if (state->SkipPadding(db)) { |
| state->listener()->OnPushPromiseEnd(); |
| return DecodeStatus::kDecodeDone; |
| } |
| payload_state_ = PayloadState::kSkipPadding; |
| return DecodeStatus::kDecodeInProgress; |
| |
| case PayloadState::kResumeDecodingPushPromiseFields: |
| status = |
| state->ResumeDecodingStructureInPayload(&push_promise_fields_, db); |
| if (status == DecodeStatus::kDecodeDone) { |
| // Finished decoding the Promised Stream ID. Can now tell the listener |
| // that we're starting to decode a PUSH_PROMISE frame. |
| ReportPushPromise(state); |
| payload_state_ = PayloadState::kReadPayload; |
| continue; |
| } |
| payload_state_ = PayloadState::kResumeDecodingPushPromiseFields; |
| return status; |
| } |
| QUICHE_BUG(http2_bug_183_1) << "PayloadState: " << payload_state_; |
| } |
| } |
| |
| void PushPromisePayloadDecoder::ReportPushPromise(FrameDecoderState* state) { |
| const Http2FrameHeader& frame_header = state->frame_header(); |
| if (frame_header.IsPadded()) { |
| state->listener()->OnPushPromiseStart(frame_header, push_promise_fields_, |
| 1 + state->remaining_padding()); |
| } else { |
| state->listener()->OnPushPromiseStart(frame_header, push_promise_fields_, |
| 0); |
| } |
| } |
| |
| } // namespace http2 |