Add a CongestionController fuzzer.

webrtc/test/fuzzers/congestion_controller_fuzzer.cc

+/*
+ *  Copyright (c) 2015 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 "webrtc/call/mock/mock_rtc_event_log.h"
+#include "webrtc/modules/congestion_controller/include/congestion_controller.h"
+#include "webrtc/modules/congestion_controller/include/mock/mock_congestion_controller.h"
+#include "webrtc/modules/remote_bitrate_estimator/include/mock/mock_remote_bitrate_estimator.h"
+#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
+
+namespace webrtc {
+
+void FuzzOneInput(const uint8_t* data, size_t size) {
+  size_t i = 0;
+  const size_t kMinSize = sizeof(size_t) + sizeof(uint16_t) + sizeof(uint8_t);

[pbos-webrtc, 2016/07/18 08:02:52]

Something like kMinPacketSize?

[stefan-webrtc, 2016/07/18 15:46:56]

Roughly, it also includes the size of the packet. But sure, it's a better name
:)

+  if (size < sizeof(int64_t) + sizeof(uint8_t) + sizeof(uint32_t) + kMinSize)

[pbos-webrtc, 2016/07/18 08:02:52]

You can permit this to run with 0 packets as well, kMinSize is sufficient to
check at line 37. Then it has possibly better coverage (running process without
inserting packets).

[stefan-webrtc, 2016/07/18 15:46:56]

Good suggestion, fixing.

+    return;
+  SimulatedClock clock(data[i++]);
+  testing::NiceMock<test::MockCongestionObserver> observer;
+  testing::NiceMock<MockRemoteBitrateObserver> rbe_observer;
+  testing::NiceMock<MockRtcEventLog> event_log;
+  CongestionController cc(&clock, &observer, &rbe_observer, &event_log);
+  RemoteBitrateEstimator* rbe = cc.GetRemoteBitrateEstimator(true);
+  RTPHeader header;
+  header.ssrc = ByteReader<uint32_t>::ReadBigEndian(&data[i]);
+  i += sizeof(uint32_t);
+  header.extension.hasTransportSequenceNumber = true;
+  int64_t arrival_time_ms =
+      std::max<int64_t>(ByteReader<int64_t>::ReadBigEndian(&data[i]), 0);
+  i += sizeof(int64_t);
+  while (i + kMinSize < size) {
+    size_t payload_size = ByteReader<size_t>::ReadBigEndian(&data[i]) % 1500;
+    i += sizeof(size_t);
+    header.extension.transportSequenceNumber =
+        ByteReader<uint16_t>::ReadBigEndian(&data[i]);
+    i += sizeof(uint16_t);
+    rbe->IncomingPacket(arrival_time_ms, payload_size, header);
+    clock.AdvanceTimeMilliseconds(5);
+    arrival_time_ms += ByteReader<uint8_t>::ReadBigEndian(&data[i]);
+    arrival_time_ms += sizeof(uint8_t);
+  }
+  rbe->Process();
+}
+}  // namespace webrtc