7a4116aa54
BUG=webrtc:5260 Review URL: https://codereview.webrtc.org/1582323005 Cr-Commit-Position: refs/heads/master@{#11981}
108 lines
3.4 KiB
C++
108 lines
3.4 KiB
C++
/*
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* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/modules/rtp_rtcp/source/rtcp_packet.h"
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#include "webrtc/base/checks.h"
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#include "webrtc/base/logging.h"
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#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
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namespace webrtc {
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namespace rtcp {
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namespace {
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void AssignUWord8(uint8_t* buffer, size_t* offset, uint8_t value) {
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buffer[(*offset)++] = value;
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}
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void AssignUWord16(uint8_t* buffer, size_t* offset, uint16_t value) {
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ByteWriter<uint16_t>::WriteBigEndian(buffer + *offset, value);
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*offset += 2;
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}
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} // namespace
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rtc::Buffer RtcpPacket::Build() const {
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size_t length = 0;
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rtc::Buffer packet(IP_PACKET_SIZE);
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class PacketVerifier : public PacketReadyCallback {
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public:
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explicit PacketVerifier(rtc::Buffer* packet)
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: called_(false), packet_(packet) {}
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virtual ~PacketVerifier() {}
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void OnPacketReady(uint8_t* data, size_t length) override {
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RTC_CHECK(!called_) << "Fragmentation not supported.";
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called_ = true;
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packet_->SetSize(length);
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}
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private:
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bool called_;
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rtc::Buffer* const packet_;
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} verifier(&packet);
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Create(packet.data(), &length, packet.capacity(), &verifier);
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OnBufferFull(packet.data(), &length, &verifier);
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return packet;
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}
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bool RtcpPacket::Build(PacketReadyCallback* callback) const {
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uint8_t buffer[IP_PACKET_SIZE];
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return BuildExternalBuffer(buffer, IP_PACKET_SIZE, callback);
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}
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bool RtcpPacket::BuildExternalBuffer(uint8_t* buffer,
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size_t max_length,
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PacketReadyCallback* callback) const {
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size_t index = 0;
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if (!Create(buffer, &index, max_length, callback))
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return false;
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return OnBufferFull(buffer, &index, callback);
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}
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bool RtcpPacket::OnBufferFull(uint8_t* packet,
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size_t* index,
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RtcpPacket::PacketReadyCallback* callback) const {
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if (*index == 0)
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return false;
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callback->OnPacketReady(packet, *index);
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*index = 0;
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return true;
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}
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size_t RtcpPacket::HeaderLength() const {
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size_t length_in_bytes = BlockLength();
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// Length in 32-bit words minus 1.
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assert(length_in_bytes > 0);
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return ((length_in_bytes + 3) / 4) - 1;
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}
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// From RFC 3550, RTP: A Transport Protocol for Real-Time Applications.
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//
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// RTP header format.
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// 0 1 2 3
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// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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// |V=2|P| RC/FMT | PT | length |
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// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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void RtcpPacket::CreateHeader(
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uint8_t count_or_format, // Depends on packet type.
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uint8_t packet_type,
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size_t length,
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uint8_t* buffer,
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size_t* pos) {
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assert(length <= 0xffff);
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const uint8_t kVersion = 2;
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AssignUWord8(buffer, pos, (kVersion << 6) + count_or_format);
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AssignUWord8(buffer, pos, packet_type);
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AssignUWord16(buffer, pos, length);
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}
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} // namespace rtcp
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} // namespace webrtc
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