| // 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 "http2/decoder/payload_decoders/altsvc_payload_decoder.h" |
| |
| #include <stddef.h> |
| |
| #include "absl/base/macros.h" |
| #include "http2/decoder/decode_buffer.h" |
| #include "http2/decoder/http2_frame_decoder_listener.h" |
| #include "http2/http2_constants.h" |
| #include "http2/http2_structures.h" |
| #include "http2/platform/api/http2_bug_tracker.h" |
| #include "http2/platform/api/http2_logging.h" |
| |
| namespace http2 { |
| |
| std::ostream& operator<<(std::ostream& out, |
| AltSvcPayloadDecoder::PayloadState v) { |
| switch (v) { |
| case AltSvcPayloadDecoder::PayloadState::kStartDecodingStruct: |
| return out << "kStartDecodingStruct"; |
| case AltSvcPayloadDecoder::PayloadState::kMaybeDecodedStruct: |
| return out << "kMaybeDecodedStruct"; |
| case AltSvcPayloadDecoder::PayloadState::kDecodingStrings: |
| return out << "kDecodingStrings"; |
| case AltSvcPayloadDecoder::PayloadState::kResumeDecodingStruct: |
| return out << "kResumeDecodingStruct"; |
| } |
| // Since the value doesn't come over the wire, only a programming bug should |
| // result in reaching this point. |
| int unknown = static_cast<int>(v); |
| HTTP2_BUG(http2_bug_163_1) |
| << "Invalid AltSvcPayloadDecoder::PayloadState: " << unknown; |
| return out << "AltSvcPayloadDecoder::PayloadState(" << unknown << ")"; |
| } |
| |
| DecodeStatus AltSvcPayloadDecoder::StartDecodingPayload( |
| FrameDecoderState* state, |
| DecodeBuffer* db) { |
| HTTP2_DVLOG(2) << "AltSvcPayloadDecoder::StartDecodingPayload: " |
| << state->frame_header(); |
| QUICHE_DCHECK_EQ(Http2FrameType::ALTSVC, state->frame_header().type); |
| QUICHE_DCHECK_LE(db->Remaining(), state->frame_header().payload_length); |
| QUICHE_DCHECK_EQ(0, state->frame_header().flags); |
| |
| state->InitializeRemainders(); |
| payload_state_ = PayloadState::kStartDecodingStruct; |
| |
| return ResumeDecodingPayload(state, db); |
| } |
| |
| DecodeStatus AltSvcPayloadDecoder::ResumeDecodingPayload( |
| FrameDecoderState* state, |
| DecodeBuffer* db) { |
| const Http2FrameHeader& frame_header = state->frame_header(); |
| HTTP2_DVLOG(2) << "AltSvcPayloadDecoder::ResumeDecodingPayload: " |
| << frame_header; |
| QUICHE_DCHECK_EQ(Http2FrameType::ALTSVC, frame_header.type); |
| QUICHE_DCHECK_LE(state->remaining_payload(), frame_header.payload_length); |
| QUICHE_DCHECK_LE(db->Remaining(), state->remaining_payload()); |
| QUICHE_DCHECK_NE(PayloadState::kMaybeDecodedStruct, payload_state_); |
| // |status| has to be initialized to some value to avoid compiler error in |
| // case PayloadState::kMaybeDecodedStruct below, but value does not matter, |
| // see QUICHE_DCHECK_NE above. |
| DecodeStatus status = DecodeStatus::kDecodeError; |
| while (true) { |
| HTTP2_DVLOG(2) |
| << "AltSvcPayloadDecoder::ResumeDecodingPayload payload_state_=" |
| << payload_state_; |
| switch (payload_state_) { |
| case PayloadState::kStartDecodingStruct: |
| status = state->StartDecodingStructureInPayload(&altsvc_fields_, db); |
| ABSL_FALLTHROUGH_INTENDED; |
| |
| case PayloadState::kMaybeDecodedStruct: |
| if (status == DecodeStatus::kDecodeDone && |
| altsvc_fields_.origin_length <= state->remaining_payload()) { |
| size_t origin_length = altsvc_fields_.origin_length; |
| size_t value_length = state->remaining_payload() - origin_length; |
| state->listener()->OnAltSvcStart(frame_header, origin_length, |
| value_length); |
| } else if (status != DecodeStatus::kDecodeDone) { |
| QUICHE_DCHECK(state->remaining_payload() > 0 || |
| status == DecodeStatus::kDecodeError) |
| << "\nremaining_payload: " << state->remaining_payload() |
| << "\nstatus: " << status << "\nheader: " << frame_header; |
| // Assume in progress. |
| payload_state_ = PayloadState::kResumeDecodingStruct; |
| return status; |
| } else { |
| // The origin's length is longer than the remaining payload. |
| QUICHE_DCHECK_GT(altsvc_fields_.origin_length, |
| state->remaining_payload()); |
| return state->ReportFrameSizeError(); |
| } |
| ABSL_FALLTHROUGH_INTENDED; |
| |
| case PayloadState::kDecodingStrings: |
| return DecodeStrings(state, db); |
| |
| case PayloadState::kResumeDecodingStruct: |
| status = state->ResumeDecodingStructureInPayload(&altsvc_fields_, db); |
| payload_state_ = PayloadState::kMaybeDecodedStruct; |
| continue; |
| } |
| HTTP2_BUG(http2_bug_163_2) << "PayloadState: " << payload_state_; |
| } |
| } |
| |
| DecodeStatus AltSvcPayloadDecoder::DecodeStrings(FrameDecoderState* state, |
| DecodeBuffer* db) { |
| HTTP2_DVLOG(2) << "AltSvcPayloadDecoder::DecodeStrings remaining_payload=" |
| << state->remaining_payload() |
| << ", db->Remaining=" << db->Remaining(); |
| // Note that we don't explicitly keep track of exactly how far through the |
| // origin; instead we compute it from how much is left of the original |
| // payload length and the decoded total length of the origin. |
| size_t origin_length = altsvc_fields_.origin_length; |
| size_t value_length = state->frame_header().payload_length - origin_length - |
| Http2AltSvcFields::EncodedSize(); |
| if (state->remaining_payload() > value_length) { |
| size_t remaining_origin_length = state->remaining_payload() - value_length; |
| size_t avail = db->MinLengthRemaining(remaining_origin_length); |
| state->listener()->OnAltSvcOriginData(db->cursor(), avail); |
| db->AdvanceCursor(avail); |
| state->ConsumePayload(avail); |
| if (remaining_origin_length > avail) { |
| payload_state_ = PayloadState::kDecodingStrings; |
| return DecodeStatus::kDecodeInProgress; |
| } |
| } |
| // All that is left is the value string. |
| QUICHE_DCHECK_LE(state->remaining_payload(), value_length); |
| QUICHE_DCHECK_LE(db->Remaining(), state->remaining_payload()); |
| if (db->HasData()) { |
| size_t avail = db->Remaining(); |
| state->listener()->OnAltSvcValueData(db->cursor(), avail); |
| db->AdvanceCursor(avail); |
| state->ConsumePayload(avail); |
| } |
| if (state->remaining_payload() == 0) { |
| state->listener()->OnAltSvcEnd(); |
| return DecodeStatus::kDecodeDone; |
| } |
| payload_state_ = PayloadState::kDecodingStrings; |
| return DecodeStatus::kDecodeInProgress; |
| } |
| |
| } // namespace http2 |