/* * 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/rtcp_packet/sender_report.h" #include <utility> #include "modules/rtp_rtcp/source/byte_io.h" #include "modules/rtp_rtcp/source/rtcp_packet/common_header.h" #include "rtc_base/checks.h" #include "rtc_base/logging.h" namespace webrtc { namespace rtcp { constexpr uint8_t SenderReport::kPacketType; constexpr size_t SenderReport::kMaxNumberOfReportBlocks; constexpr size_t SenderReport::kSenderBaseLength; // Sender report (SR) (RFC 3550). // 0 1 2 3 // 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 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // |V=2|P| RC | PT=SR=200 | length | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // 0 | SSRC of sender | // +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ // 4 | NTP timestamp, most significant word | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // 8 | NTP timestamp, least significant word | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // 12 | RTP timestamp | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // 16 | sender's packet count | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // 20 | sender's octet count | // 24 +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ SenderReport::SenderReport() : rtp_timestamp_(0), sender_packet_count_(0), sender_octet_count_(0) {} SenderReport::SenderReport(const SenderReport&) = default; SenderReport::SenderReport(SenderReport&&) = default; SenderReport& SenderReport::operator=(const SenderReport&) = default; SenderReport& SenderReport::operator=(SenderReport&&) = default; SenderReport::~SenderReport() = default; bool SenderReport::Parse(const CommonHeader& packet) { RTC_DCHECK_EQ(packet.type(), kPacketType); const uint8_t report_block_count = packet.count(); if (packet.payload_size_bytes() < kSenderBaseLength + report_block_count * ReportBlock::kLength) { RTC_LOG(LS_WARNING) << "Packet is too small to contain all the data."; return false; } // Read SenderReport header. const uint8_t* const payload = packet.payload(); SetSenderSsrc(ByteReader<uint32_t>::ReadBigEndian(&payload[0])); uint32_t secs = ByteReader<uint32_t>::ReadBigEndian(&payload[4]); uint32_t frac = ByteReader<uint32_t>::ReadBigEndian(&payload[8]); ntp_.Set(secs, frac); rtp_timestamp_ = ByteReader<uint32_t>::ReadBigEndian(&payload[12]); sender_packet_count_ = ByteReader<uint32_t>::ReadBigEndian(&payload[16]); sender_octet_count_ = ByteReader<uint32_t>::ReadBigEndian(&payload[20]); report_blocks_.resize(report_block_count); const uint8_t* next_block = payload + kSenderBaseLength; for (ReportBlock& block : report_blocks_) { bool block_parsed = block.Parse(next_block, ReportBlock::kLength); RTC_DCHECK(block_parsed); next_block += ReportBlock::kLength; } // Double check we didn't read beyond provided buffer. RTC_DCHECK_LE(next_block - payload, static_cast<ptrdiff_t>(packet.payload_size_bytes())); return true; } size_t SenderReport::BlockLength() const { return kHeaderLength + kSenderBaseLength + report_blocks_.size() * ReportBlock::kLength; } bool SenderReport::Create(uint8_t* packet, size_t* index, size_t max_length, PacketReadyCallback callback) const { while (*index + BlockLength() > max_length) { if (!OnBufferFull(packet, index, callback)) return false; } const size_t index_end = *index + BlockLength(); CreateHeader(report_blocks_.size(), kPacketType, HeaderLength(), packet, index); // Write SenderReport header. ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 0], sender_ssrc()); ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 4], ntp_.seconds()); ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 8], ntp_.fractions()); ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 12], rtp_timestamp_); ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 16], sender_packet_count_); ByteWriter<uint32_t>::WriteBigEndian(&packet[*index + 20], sender_octet_count_); *index += kSenderBaseLength; // Write report blocks. for (const ReportBlock& block : report_blocks_) { block.Create(packet + *index); *index += ReportBlock::kLength; } // Ensure bytes written match expected. RTC_DCHECK_EQ(*index, index_end); return true; } bool SenderReport::AddReportBlock(const ReportBlock& block) { if (report_blocks_.size() >= kMaxNumberOfReportBlocks) { RTC_LOG(LS_WARNING) << "Max report blocks reached."; return false; } report_blocks_.push_back(block); return true; } bool SenderReport::SetReportBlocks(std::vector<ReportBlock> blocks) { if (blocks.size() > kMaxNumberOfReportBlocks) { RTC_LOG(LS_WARNING) << "Too many report blocks (" << blocks.size() << ") for sender report."; return false; } report_blocks_ = std::move(blocks); return true; } } // namespace rtcp } // namespace webrtc