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/*
* Copyright (c) 2016 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 "modules/rtp_rtcp/source/ulpfec_header_reader_writer.h"
#include <string.h>
#include <memory>
#include <utility>
#include "api/scoped_refptr.h"
#include "modules/rtp_rtcp/source/byte_io.h"
#include "modules/rtp_rtcp/source/forward_error_correction.h"
#include "modules/rtp_rtcp/source/forward_error_correction_internal.h"
#include "rtc_base/checks.h"
#include "rtc_base/random.h"
#include "test/gmock.h"
#include "test/gtest.h"
namespace webrtc {
namespace {
using Packet = ForwardErrorCorrection::Packet;
using ReceivedFecPacket = ForwardErrorCorrection::ReceivedFecPacket;
using ::testing::SizeIs;
constexpr uint32_t kMediaSsrc = 1254983;
constexpr uint16_t kMediaStartSeqNum = 825;
constexpr size_t kMediaPacketLength = 1234;
constexpr size_t kUlpfecHeaderSizeLBitClear = 14;
constexpr size_t kUlpfecHeaderSizeLBitSet = 18;
constexpr size_t kUlpfecPacketMaskOffset = 12;
std::unique_ptr<uint8_t[]> GeneratePacketMask(size_t packet_mask_size,
uint64_t seed) {
Random random(seed);
std::unique_ptr<uint8_t[]> packet_mask(new uint8_t[packet_mask_size]);
for (size_t i = 0; i < packet_mask_size; ++i) {
packet_mask[i] = random.Rand<uint8_t>();
}
return packet_mask;
}
std::unique_ptr<Packet> WriteHeader(const uint8_t* packet_mask,
size_t packet_mask_size) {
UlpfecHeaderWriter writer;
std::unique_ptr<Packet> written_packet(new Packet());
written_packet->data.SetSize(kMediaPacketLength);
uint8_t* data = written_packet->data.MutableData();
for (size_t i = 0; i < written_packet->data.size(); ++i) {
data[i] = i; // Actual content doesn't matter.
}
const FecHeaderWriter::ProtectedStream protected_streams[] = {
{.ssrc = kMediaSsrc,
.seq_num_base = kMediaStartSeqNum,
.packet_mask = {packet_mask, packet_mask_size}}};
writer.FinalizeFecHeader(protected_streams, *written_packet);
return written_packet;
}
std::unique_ptr<ReceivedFecPacket> ReadHeader(const Packet& written_packet) {
UlpfecHeaderReader reader;
std::unique_ptr<ReceivedFecPacket> read_packet(new ReceivedFecPacket());
read_packet->ssrc = kMediaSsrc;
read_packet->pkt = rtc::scoped_refptr<Packet>(new Packet());
read_packet->pkt->data = written_packet.data;
EXPECT_TRUE(reader.ReadFecHeader(read_packet.get()));
return read_packet;
}
void VerifyHeaders(size_t expected_fec_header_size,
const uint8_t* expected_packet_mask,
size_t expected_packet_mask_size,
const Packet& written_packet,
const ReceivedFecPacket& read_packet) {
EXPECT_EQ(kMediaSsrc, read_packet.ssrc);
EXPECT_EQ(expected_fec_header_size, read_packet.fec_header_size);
ASSERT_THAT(read_packet.protected_streams, SizeIs(1));
EXPECT_EQ(read_packet.protected_streams[0].ssrc, kMediaSsrc);
EXPECT_EQ(read_packet.protected_streams[0].seq_num_base, kMediaStartSeqNum);
EXPECT_EQ(read_packet.protected_streams[0].packet_mask_offset,
kUlpfecPacketMaskOffset);
ASSERT_EQ(read_packet.protected_streams[0].packet_mask_size,
expected_packet_mask_size);
EXPECT_EQ(written_packet.data.size() - expected_fec_header_size,
read_packet.protection_length);
EXPECT_EQ(0, memcmp(expected_packet_mask,
read_packet.pkt->data.MutableData() +
read_packet.protected_streams[0].packet_mask_offset,
read_packet.protected_streams[0].packet_mask_size));
// Verify that the call to ReadFecHeader did not tamper with the payload.
EXPECT_EQ(0, memcmp(written_packet.data.data() + expected_fec_header_size,
read_packet.pkt->data.cdata() + expected_fec_header_size,
written_packet.data.size() - expected_fec_header_size));
}
} // namespace
TEST(UlpfecHeaderReaderTest, ReadsSmallHeader) {
const uint8_t packet[] = {
0x00, 0x12, 0xab, 0xcd, // L bit clear, "random" payload type and SN base
0x12, 0x34, 0x56, 0x78, // "random" TS recovery
0xab, 0xcd, 0x11, 0x22, // "random" length recovery and protection length
0x33, 0x44, // "random" packet mask
0x00, 0x00, 0x00, 0x00 // payload
};
const size_t packet_length = sizeof(packet);
ReceivedFecPacket read_packet;
read_packet.pkt = rtc::scoped_refptr<Packet>(new Packet());
read_packet.pkt->data.SetData(packet, packet_length);
UlpfecHeaderReader reader;
EXPECT_TRUE(reader.ReadFecHeader(&read_packet));
EXPECT_EQ(14U, read_packet.fec_header_size);
EXPECT_EQ(0xabcdU, read_packet.protected_streams[0].seq_num_base);
EXPECT_EQ(12U, read_packet.protected_streams[0].packet_mask_offset);
EXPECT_EQ(2U, read_packet.protected_streams[0].packet_mask_size);
EXPECT_EQ(0x1122U, read_packet.protection_length);
}
TEST(UlpfecHeaderReaderTest, ReadsLargeHeader) {
const uint8_t packet[] = {
0x40, 0x12, 0xab, 0xcd, // L bit set, "random" payload type and SN base
0x12, 0x34, 0x56, 0x78, // "random" TS recovery
0xab, 0xcd, 0x11, 0x22, // "random" length recovery and protection length
0x33, 0x44, 0x55, 0x66, // "random" packet mask
0x77, 0x88, //
0x00, 0x00, 0x00, 0x00 // payload
};
const size_t packet_length = sizeof(packet);
ReceivedFecPacket read_packet;
read_packet.pkt = rtc::scoped_refptr<Packet>(new Packet());
read_packet.pkt->data.SetData(packet, packet_length);
UlpfecHeaderReader reader;
EXPECT_TRUE(reader.ReadFecHeader(&read_packet));
EXPECT_EQ(18U, read_packet.fec_header_size);
EXPECT_EQ(0xabcdU, read_packet.protected_streams[0].seq_num_base);
EXPECT_EQ(12U, read_packet.protected_streams[0].packet_mask_offset);
EXPECT_EQ(6U, read_packet.protected_streams[0].packet_mask_size);
EXPECT_EQ(0x1122U, read_packet.protection_length);
}
TEST(UlpfecHeaderWriterTest, FinalizesSmallHeader) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
Packet written_packet;
written_packet.data.SetSize(kMediaPacketLength);
uint8_t* data = written_packet.data.MutableData();
for (size_t i = 0; i < written_packet.data.size(); ++i) {
data[i] = i;
}
UlpfecHeaderWriter writer;
const FecHeaderWriter::ProtectedStream protected_streams[] = {
{.ssrc = kMediaSsrc,
.seq_num_base = kMediaStartSeqNum,
.packet_mask = {packet_mask.get(), packet_mask_size}}};
writer.FinalizeFecHeader(protected_streams, written_packet);
const uint8_t* packet = written_packet.data.cdata();
EXPECT_EQ(0x00, packet[0] & 0x80); // E bit.
EXPECT_EQ(0x00, packet[0] & 0x40); // L bit.
EXPECT_EQ(kMediaStartSeqNum, ByteReader<uint16_t>::ReadBigEndian(packet + 2));
EXPECT_EQ(
static_cast<uint16_t>(kMediaPacketLength - kUlpfecHeaderSizeLBitClear),
ByteReader<uint16_t>::ReadBigEndian(packet + 10));
EXPECT_EQ(0, memcmp(packet + kUlpfecPacketMaskOffset, packet_mask.get(),
packet_mask_size));
}
TEST(UlpfecHeaderWriterTest, FinalizesLargeHeader) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
Packet written_packet;
written_packet.data.SetSize(kMediaPacketLength);
uint8_t* data = written_packet.data.MutableData();
for (size_t i = 0; i < written_packet.data.size(); ++i) {
data[i] = i;
}
UlpfecHeaderWriter writer;
const FecHeaderWriter::ProtectedStream protected_streams[] = {
{.ssrc = kMediaSsrc,
.seq_num_base = kMediaStartSeqNum,
.packet_mask = {packet_mask.get(), packet_mask_size}}};
writer.FinalizeFecHeader(protected_streams, written_packet);
const uint8_t* packet = written_packet.data.cdata();
EXPECT_EQ(0x00, packet[0] & 0x80); // E bit.
EXPECT_EQ(0x40, packet[0] & 0x40); // L bit.
EXPECT_EQ(kMediaStartSeqNum, ByteReader<uint16_t>::ReadBigEndian(packet + 2));
EXPECT_EQ(
static_cast<uint16_t>(kMediaPacketLength - kUlpfecHeaderSizeLBitSet),
ByteReader<uint16_t>::ReadBigEndian(packet + 10));
EXPECT_EQ(0, memcmp(packet + kUlpfecPacketMaskOffset, packet_mask.get(),
packet_mask_size));
}
TEST(UlpfecHeaderWriterTest, CalculateSmallHeaderSize) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
UlpfecHeaderWriter writer;
size_t min_packet_mask_size =
writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size);
EXPECT_EQ(kUlpfecPacketMaskSizeLBitClear, min_packet_mask_size);
EXPECT_EQ(kUlpfecHeaderSizeLBitClear,
writer.FecHeaderSize(min_packet_mask_size));
}
TEST(UlpfecHeaderWriterTest, CalculateLargeHeaderSize) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
UlpfecHeaderWriter writer;
size_t min_packet_mask_size =
writer.MinPacketMaskSize(packet_mask.get(), packet_mask_size);
EXPECT_EQ(kUlpfecPacketMaskSizeLBitSet, min_packet_mask_size);
EXPECT_EQ(kUlpfecHeaderSizeLBitSet,
writer.FecHeaderSize(min_packet_mask_size));
}
TEST(UlpfecHeaderReaderWriterTest, WriteAndReadSmallHeader) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitClear;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size);
auto read_packet = ReadHeader(*written_packet);
VerifyHeaders(kUlpfecHeaderSizeLBitClear, packet_mask.get(), packet_mask_size,
*written_packet, *read_packet);
}
TEST(UlpfecHeaderReaderWriterTest, WriteAndReadLargeHeader) {
const size_t packet_mask_size = kUlpfecPacketMaskSizeLBitSet;
auto packet_mask = GeneratePacketMask(packet_mask_size, 0xabcd);
auto written_packet = WriteHeader(packet_mask.get(), packet_mask_size);
auto read_packet = ReadHeader(*written_packet);
VerifyHeaders(kUlpfecHeaderSizeLBitSet, packet_mask.get(), packet_mask_size,
*written_packet, *read_packet);
}
} // namespace webrtc
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