blob: 449d6493802e3596be787c54569f9bf2cb7ba95d [file] [log] [blame]
// 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/http2_frame_decoder.h"
#include "http2/decoder/decode_status.h"
#include "http2/hpack/varint/hpack_varint_decoder.h"
#include "http2/http2_constants.h"
#include "http2/platform/api/http2_bug_tracker.h"
#include "http2/platform/api/http2_flag_utils.h"
#include "http2/platform/api/http2_flags.h"
#include "http2/platform/api/http2_macros.h"
namespace http2 {
std::ostream& operator<<(std::ostream& out, Http2FrameDecoder::State v) {
switch (v) {
case Http2FrameDecoder::State::kStartDecodingHeader:
return out << "kStartDecodingHeader";
case Http2FrameDecoder::State::kResumeDecodingHeader:
return out << "kResumeDecodingHeader";
case Http2FrameDecoder::State::kResumeDecodingPayload:
return out << "kResumeDecodingPayload";
case Http2FrameDecoder::State::kDiscardPayload:
return out << "kDiscardPayload";
}
// 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 << "Http2FrameDecoder::State " << unknown;
return out << "Http2FrameDecoder::State(" << unknown << ")";
}
Http2FrameDecoder::Http2FrameDecoder(Http2FrameDecoderListener* listener)
: state_(State::kStartDecodingHeader),
maximum_payload_size_(Http2SettingsInfo::DefaultMaxFrameSize()) {
set_listener(listener);
}
void Http2FrameDecoder::set_listener(Http2FrameDecoderListener* listener) {
if (listener == nullptr) {
listener = &no_op_listener_;
}
frame_decoder_state_.set_listener(listener);
}
Http2FrameDecoderListener* Http2FrameDecoder::listener() const {
return frame_decoder_state_.listener();
}
DecodeStatus Http2FrameDecoder::DecodeFrame(DecodeBuffer* db) {
HTTP2_DVLOG(2) << "Http2FrameDecoder::DecodeFrame state=" << state_;
switch (state_) {
case State::kStartDecodingHeader:
if (frame_decoder_state_.StartDecodingFrameHeader(db)) {
return StartDecodingPayload(db);
}
state_ = State::kResumeDecodingHeader;
return DecodeStatus::kDecodeInProgress;
case State::kResumeDecodingHeader:
if (frame_decoder_state_.ResumeDecodingFrameHeader(db)) {
return StartDecodingPayload(db);
}
return DecodeStatus::kDecodeInProgress;
case State::kResumeDecodingPayload:
return ResumeDecodingPayload(db);
case State::kDiscardPayload:
return DiscardPayload(db);
}
HTTP2_UNREACHABLE();
return DecodeStatus::kDecodeError;
}
size_t Http2FrameDecoder::remaining_payload() const {
return frame_decoder_state_.remaining_payload();
}
uint32_t Http2FrameDecoder::remaining_padding() const {
return frame_decoder_state_.remaining_padding();
}
DecodeStatus Http2FrameDecoder::StartDecodingPayload(DecodeBuffer* db) {
const Http2FrameHeader& header = frame_header();
// TODO(jamessynge): Remove OnFrameHeader once done with supporting
// SpdyFramer's exact states.
if (!listener()->OnFrameHeader(header)) {
HTTP2_DVLOG(2) << "OnFrameHeader rejected the frame, will discard; header: "
<< header;
state_ = State::kDiscardPayload;
frame_decoder_state_.InitializeRemainders();
return DecodeStatus::kDecodeError;
}
if (header.payload_length > maximum_payload_size_) {
HTTP2_DVLOG(2) << "Payload length is greater than allowed: "
<< header.payload_length << " > " << maximum_payload_size_
<< "\n header: " << header;
state_ = State::kDiscardPayload;
frame_decoder_state_.InitializeRemainders();
listener()->OnFrameSizeError(header);
return DecodeStatus::kDecodeError;
}
// The decode buffer can extend across many frames. Make sure that the
// buffer we pass to the start method that is specific to the frame type
// does not exend beyond this frame.
DecodeBufferSubset subset(db, header.payload_length);
DecodeStatus status;
switch (header.type) {
case Http2FrameType::DATA:
status = StartDecodingDataPayload(&subset);
break;
case Http2FrameType::HEADERS:
status = StartDecodingHeadersPayload(&subset);
break;
case Http2FrameType::PRIORITY:
status = StartDecodingPriorityPayload(&subset);
break;
case Http2FrameType::RST_STREAM:
status = StartDecodingRstStreamPayload(&subset);
break;
case Http2FrameType::SETTINGS:
status = StartDecodingSettingsPayload(&subset);
break;
case Http2FrameType::PUSH_PROMISE:
status = StartDecodingPushPromisePayload(&subset);
break;
case Http2FrameType::PING:
status = StartDecodingPingPayload(&subset);
break;
case Http2FrameType::GOAWAY:
status = StartDecodingGoAwayPayload(&subset);
break;
case Http2FrameType::WINDOW_UPDATE:
status = StartDecodingWindowUpdatePayload(&subset);
break;
case Http2FrameType::CONTINUATION:
status = StartDecodingContinuationPayload(&subset);
break;
case Http2FrameType::ALTSVC:
status = StartDecodingAltSvcPayload(&subset);
break;
case Http2FrameType::PRIORITY_UPDATE:
if (GetHttp2RestartFlag(http2_parse_priority_update_frame)) {
HTTP2_RESTART_FLAG_COUNT_N(http2_parse_priority_update_frame, 1, 2);
status = StartDecodingPriorityUpdatePayload(&subset);
} else {
status = StartDecodingUnknownPayload(&subset);
}
break;
default:
status = StartDecodingUnknownPayload(&subset);
break;
}
if (status == DecodeStatus::kDecodeDone) {
state_ = State::kStartDecodingHeader;
return status;
} else if (status == DecodeStatus::kDecodeInProgress) {
state_ = State::kResumeDecodingPayload;
return status;
} else {
state_ = State::kDiscardPayload;
return status;
}
}
DecodeStatus Http2FrameDecoder::ResumeDecodingPayload(DecodeBuffer* db) {
// The decode buffer can extend across many frames. Make sure that the
// buffer we pass to the start method that is specific to the frame type
// does not exend beyond this frame.
size_t remaining = frame_decoder_state_.remaining_total_payload();
QUICHE_DCHECK_LE(remaining, frame_header().payload_length);
DecodeBufferSubset subset(db, remaining);
DecodeStatus status;
switch (frame_header().type) {
case Http2FrameType::DATA:
status = ResumeDecodingDataPayload(&subset);
break;
case Http2FrameType::HEADERS:
status = ResumeDecodingHeadersPayload(&subset);
break;
case Http2FrameType::PRIORITY:
status = ResumeDecodingPriorityPayload(&subset);
break;
case Http2FrameType::RST_STREAM:
status = ResumeDecodingRstStreamPayload(&subset);
break;
case Http2FrameType::SETTINGS:
status = ResumeDecodingSettingsPayload(&subset);
break;
case Http2FrameType::PUSH_PROMISE:
status = ResumeDecodingPushPromisePayload(&subset);
break;
case Http2FrameType::PING:
status = ResumeDecodingPingPayload(&subset);
break;
case Http2FrameType::GOAWAY:
status = ResumeDecodingGoAwayPayload(&subset);
break;
case Http2FrameType::WINDOW_UPDATE:
status = ResumeDecodingWindowUpdatePayload(&subset);
break;
case Http2FrameType::CONTINUATION:
status = ResumeDecodingContinuationPayload(&subset);
break;
case Http2FrameType::ALTSVC:
status = ResumeDecodingAltSvcPayload(&subset);
break;
case Http2FrameType::PRIORITY_UPDATE:
if (GetHttp2RestartFlag(http2_parse_priority_update_frame)) {
HTTP2_RESTART_FLAG_COUNT_N(http2_parse_priority_update_frame, 2, 2);
status = ResumeDecodingPriorityUpdatePayload(&subset);
} else {
status = ResumeDecodingUnknownPayload(&subset);
}
break;
default:
status = ResumeDecodingUnknownPayload(&subset);
break;
}
if (status == DecodeStatus::kDecodeDone) {
state_ = State::kStartDecodingHeader;
return status;
} else if (status == DecodeStatus::kDecodeInProgress) {
return status;
} else {
state_ = State::kDiscardPayload;
return status;
}
}
// Clear any of the flags in the frame header that aren't set in valid_flags.
void Http2FrameDecoder::RetainFlags(uint8_t valid_flags) {
frame_decoder_state_.RetainFlags(valid_flags);
}
// Clear all of the flags in the frame header; for use with frame types that
// don't define any flags, such as WINDOW_UPDATE.
void Http2FrameDecoder::ClearFlags() {
frame_decoder_state_.ClearFlags();
}
DecodeStatus Http2FrameDecoder::StartDecodingAltSvcPayload(DecodeBuffer* db) {
ClearFlags();
return altsvc_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingAltSvcPayload(DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return altsvc_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingContinuationPayload(
DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::END_HEADERS);
return continuation_payload_decoder_.StartDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingContinuationPayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return continuation_payload_decoder_.ResumeDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingDataPayload(DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::END_STREAM | Http2FrameFlag::PADDED);
return data_payload_decoder_.StartDecodingPayload(&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingDataPayload(DecodeBuffer* db) {
return data_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingGoAwayPayload(DecodeBuffer* db) {
ClearFlags();
return goaway_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingGoAwayPayload(DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return goaway_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingHeadersPayload(DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::END_STREAM | Http2FrameFlag::END_HEADERS |
Http2FrameFlag::PADDED | Http2FrameFlag::PRIORITY);
return headers_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingHeadersPayload(DecodeBuffer* db) {
QUICHE_DCHECK_LE(frame_decoder_state_.remaining_payload_and_padding(),
frame_header().payload_length);
return headers_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingPingPayload(DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::ACK);
return ping_payload_decoder_.StartDecodingPayload(&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingPingPayload(DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return ping_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingPriorityPayload(DecodeBuffer* db) {
ClearFlags();
return priority_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingPriorityPayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return priority_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingPriorityUpdatePayload(
DecodeBuffer* db) {
ClearFlags();
return priority_payload_update_decoder_.StartDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingPriorityUpdatePayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return priority_payload_update_decoder_.ResumeDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingPushPromisePayload(
DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::END_HEADERS | Http2FrameFlag::PADDED);
return push_promise_payload_decoder_.StartDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingPushPromisePayload(
DecodeBuffer* db) {
QUICHE_DCHECK_LE(frame_decoder_state_.remaining_payload_and_padding(),
frame_header().payload_length);
return push_promise_payload_decoder_.ResumeDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingRstStreamPayload(
DecodeBuffer* db) {
ClearFlags();
return rst_stream_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingRstStreamPayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return rst_stream_payload_decoder_.ResumeDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::StartDecodingSettingsPayload(DecodeBuffer* db) {
RetainFlags(Http2FrameFlag::ACK);
return settings_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingSettingsPayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return settings_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingUnknownPayload(DecodeBuffer* db) {
// We don't known what type of frame this is, so we don't know which flags
// are valid, so we don't touch them.
return unknown_payload_decoder_.StartDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingUnknownPayload(DecodeBuffer* db) {
// We don't known what type of frame this is, so we treat it as not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return unknown_payload_decoder_.ResumeDecodingPayload(&frame_decoder_state_,
db);
}
DecodeStatus Http2FrameDecoder::StartDecodingWindowUpdatePayload(
DecodeBuffer* db) {
ClearFlags();
return window_update_payload_decoder_.StartDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::ResumeDecodingWindowUpdatePayload(
DecodeBuffer* db) {
// The frame is not paddable.
QUICHE_DCHECK_EQ(frame_decoder_state_.remaining_total_payload(),
frame_decoder_state_.remaining_payload());
return window_update_payload_decoder_.ResumeDecodingPayload(
&frame_decoder_state_, db);
}
DecodeStatus Http2FrameDecoder::DiscardPayload(DecodeBuffer* db) {
HTTP2_DVLOG(2) << "remaining_payload="
<< frame_decoder_state_.remaining_payload_
<< "; remaining_padding="
<< frame_decoder_state_.remaining_padding_;
frame_decoder_state_.remaining_payload_ +=
frame_decoder_state_.remaining_padding_;
frame_decoder_state_.remaining_padding_ = 0;
const size_t avail = frame_decoder_state_.AvailablePayload(db);
HTTP2_DVLOG(2) << "avail=" << avail;
if (avail > 0) {
frame_decoder_state_.ConsumePayload(avail);
db->AdvanceCursor(avail);
}
if (frame_decoder_state_.remaining_payload_ == 0) {
state_ = State::kStartDecodingHeader;
return DecodeStatus::kDecodeDone;
}
return DecodeStatus::kDecodeInProgress;
}
} // namespace http2