1 files changed, 94 insertions, 0 deletions
diff --git a/third_party/libwebrtc/test/fuzzers/rtp_dependency_descriptor_fuzzer.cc b/third_party/libwebrtc/test/fuzzers/rtp_dependency_descriptor_fuzzer.cc
new file mode 100644
index 0000000000..82404f7264
--- /dev/null
+++ b/third_party/libwebrtc/test/fuzzers/rtp_dependency_descriptor_fuzzer.cc
@@ -0,0 +1,94 @@
+/*
+ *  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