blob: 310e8a70b9b35cd646b621cf937314f264f3e481 [file] [log] [blame]
// Copyright 2017 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/hpack/decoder/hpack_decoder.h"
#include "quiche/http2/decoder/decode_status.h"
#include "quiche/common/platform/api/quiche_flag_utils.h"
#include "quiche/common/platform/api/quiche_logging.h"
namespace http2 {
HpackDecoder::HpackDecoder(HpackDecoderListener* listener,
size_t max_string_size)
: decoder_state_(listener),
entry_buffer_(&decoder_state_, max_string_size),
block_decoder_(&entry_buffer_),
error_(HpackDecodingError::kOk) {}
HpackDecoder::~HpackDecoder() = default;
void HpackDecoder::set_max_string_size_bytes(size_t max_string_size_bytes) {
entry_buffer_.set_max_string_size_bytes(max_string_size_bytes);
}
void HpackDecoder::ApplyHeaderTableSizeSetting(uint32_t max_header_table_size) {
decoder_state_.ApplyHeaderTableSizeSetting(max_header_table_size);
}
bool HpackDecoder::StartDecodingBlock() {
QUICHE_DVLOG(3) << "HpackDecoder::StartDecodingBlock, error_detected="
<< (DetectError() ? "true" : "false");
if (DetectError()) {
return false;
}
// TODO(jamessynge): Eliminate Reset(), which shouldn't be necessary
// if there are no errors, and shouldn't be necessary with errors if
// we never resume decoding after an error has been detected.
block_decoder_.Reset();
decoder_state_.OnHeaderBlockStart();
return true;
}
bool HpackDecoder::DecodeFragment(DecodeBuffer* db) {
QUICHE_DVLOG(3) << "HpackDecoder::DecodeFragment, error_detected="
<< (DetectError() ? "true" : "false")
<< ", size=" << db->Remaining();
if (DetectError()) {
QUICHE_CODE_COUNT_N(decompress_failure_3, 3, 23);
return false;
}
// Decode contents of db as an HPACK block fragment, forwards the decoded
// entries to entry_buffer_, which in turn forwards them to decode_state_,
// which finally forwards them to the HpackDecoderListener.
DecodeStatus status = block_decoder_.Decode(db);
if (status == DecodeStatus::kDecodeError) {
ReportError(block_decoder_.error());
QUICHE_CODE_COUNT_N(decompress_failure_3, 4, 23);
return false;
} else if (DetectError()) {
QUICHE_CODE_COUNT_N(decompress_failure_3, 5, 23);
return false;
}
// Should be positioned between entries iff decoding is complete.
QUICHE_DCHECK_EQ(block_decoder_.before_entry(),
status == DecodeStatus::kDecodeDone)
<< status;
if (!block_decoder_.before_entry()) {
entry_buffer_.BufferStringsIfUnbuffered();
}
return true;
}
bool HpackDecoder::EndDecodingBlock() {
QUICHE_DVLOG(3) << "HpackDecoder::EndDecodingBlock, error_detected="
<< (DetectError() ? "true" : "false");
if (DetectError()) {
QUICHE_CODE_COUNT_N(decompress_failure_3, 6, 23);
return false;
}
if (!block_decoder_.before_entry()) {
// The HPACK block ended in the middle of an entry.
ReportError(HpackDecodingError::kTruncatedBlock);
QUICHE_CODE_COUNT_N(decompress_failure_3, 7, 23);
return false;
}
decoder_state_.OnHeaderBlockEnd();
if (DetectError()) {
// HpackDecoderState will have reported the error.
QUICHE_CODE_COUNT_N(decompress_failure_3, 8, 23);
return false;
}
return true;
}
bool HpackDecoder::DetectError() {
if (error_ != HpackDecodingError::kOk) {
return true;
}
if (decoder_state_.error() != HpackDecodingError::kOk) {
QUICHE_DVLOG(2) << "Error detected in decoder_state_";
QUICHE_CODE_COUNT_N(decompress_failure_3, 10, 23);
error_ = decoder_state_.error();
}
return error_ != HpackDecodingError::kOk;
}
void HpackDecoder::ReportError(HpackDecodingError error) {
QUICHE_DVLOG(3) << "HpackDecoder::ReportError is new="
<< (error_ == HpackDecodingError::kOk ? "true" : "false")
<< ", error: " << HpackDecodingErrorToString(error);
if (error_ == HpackDecodingError::kOk) {
error_ = error;
decoder_state_.listener()->OnHeaderErrorDetected(
HpackDecodingErrorToString(error));
}
}
} // namespace http2