rtp_dependency_descriptor_fuzzer.cc

/*

 *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.

 *  Use of this source code is governed by a BSD-style license

 *  that can be found in the LICENSE file in the root of the source

 *  tree. An additional intellectual property rights grant can be found

 *  in the file PATENTS.  All contributing project authors may

 *  be found in the AUTHORS file in the root of the source tree.

*/

#include <algorithm>

#include <cstddef>

#include <cstdint>

#include <memory>

#include <utility>

#include "api/array_view.h"

#include "common_video/generic_frame_descriptor/generic_frame_info.h"

#include "modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.h"

#include "rtc_base/checks.h"

#include "test/fuzzers/fuzz_data_helper.h"

namespace webrtc {

void FuzzOneInput(const uint8_t* data, size_t size) {

  FrameDependencyStructure structure1;

  // nullptr during 1st while loop, after that should point to structure1.

  const FrameDependencyStructure* structure1_ptr = nullptr;

  std::unique_ptr<const FrameDependencyStructure> structure2;

  test::FuzzDataHelper fuzz_data(rtc::MakeArrayView(data, size));

  while (fuzz_data.CanReadBytes(1)) {

    // Treat next byte as size of the next extension. That aligns how

    // two-byte rtp header extension sizes are written.

    size_t next_size = fuzz_data.Read<uint8_t>();

    auto raw =

        fuzz_data.ReadByteArray(std::min(next_size, fuzz_data.BytesLeft()));

    // Read the random input.

    DependencyDescriptor descriptor1;

    if (!RtpDependencyDescriptorExtension::Parse(raw, structure1_ptr,

                                                 &descriptor1)) {

      // Ignore invalid buffer and move on.

      continue;

    if (descriptor1.attached_structure) {

      structure1 = *descriptor1.attached_structure;

      structure1_ptr = &structure1;

    RTC_CHECK(structure1_ptr);

    // Write parsed descriptor back into raw buffer.

    size_t value_size =

        RtpDependencyDescriptorExtension::ValueSize(structure1, descriptor1);

    // Check `writer` use minimal number of bytes to pack the descriptor by

    // checking it doesn't use more than reader consumed.

    RTC_CHECK_LE(value_size, raw.size());

    uint8_t some_memory[256];

    // That should be true because value_size <= next_size < 256

    RTC_CHECK_LT(value_size, 256);

    rtc::ArrayView<uint8_t> write_buffer(some_memory, value_size);

    RTC_CHECK(RtpDependencyDescriptorExtension::Write(write_buffer, structure1,

                                                      descriptor1));

    // Parse what Write assembled.

    // Unlike random input that should always succeed.

    DependencyDescriptor descriptor2;

    RTC_CHECK(RtpDependencyDescriptorExtension::Parse(

        write_buffer, structure2.get(), &descriptor2));

    // Check descriptor1 and descriptor2 have same values.

    RTC_CHECK_EQ(descriptor1.first_packet_in_frame,

                 descriptor2.first_packet_in_frame);

    RTC_CHECK_EQ(descriptor1.last_packet_in_frame,

                 descriptor2.last_packet_in_frame);

    RTC_CHECK_EQ(descriptor1.attached_structure != nullptr,

                 descriptor2.attached_structure != nullptr);

    // Using value_or would miss invalid corner case when one value is nullopt

    // while another one is 0, but for other errors would produce much nicer

    // error message than using RTC_CHECK(optional1 == optional2);

    // If logger would support pretty printing optional values, value_or can be

    // removed.

    RTC_CHECK_EQ(descriptor1.active_decode_targets_bitmask.value_or(0),

                 descriptor2.active_decode_targets_bitmask.value_or(0));

    RTC_CHECK_EQ(descriptor1.frame_number, descriptor2.frame_number);

    RTC_CHECK(descriptor1.resolution == descriptor2.resolution);

    RTC_CHECK(descriptor1.frame_dependencies == descriptor2.frame_dependencies);

    if (descriptor2.attached_structure) {

      structure2 = std::move(descriptor2.attached_structure);

}  // namespace webrtc