Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/receiver_report.h"
      12             : 
      13             : #include "webrtc/base/checks.h"
      14             : #include "webrtc/base/logging.h"
      15             : #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
      16             : #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/common_header.h"
      17             : 
      18             : namespace webrtc {
      19             : namespace rtcp {
      20             : constexpr uint8_t ReceiverReport::kPacketType;
      21             : // RTCP receiver report (RFC 3550).
      22             : //
      23             : //   0                   1                   2                   3
      24             : //   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
      25             : //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      26             : //  |V=2|P|    RC   |   PT=RR=201   |             length            |
      27             : //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      28             : //  |                     SSRC of packet sender                     |
      29             : //  +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
      30             : //  |                         report block(s)                       |
      31             : //  |                            ....                               |
      32           0 : bool ReceiverReport::Parse(const CommonHeader& packet) {
      33           0 :   RTC_DCHECK_EQ(packet.type(), kPacketType);
      34             : 
      35           0 :   const uint8_t report_blocks_count = packet.count();
      36             : 
      37           0 :   if (packet.payload_size_bytes() <
      38           0 :       kRrBaseLength + report_blocks_count * ReportBlock::kLength) {
      39           0 :     LOG(LS_WARNING) << "Packet is too small to contain all the data.";
      40           0 :     return false;
      41             :   }
      42             : 
      43           0 :   sender_ssrc_ = ByteReader<uint32_t>::ReadBigEndian(packet.payload());
      44             : 
      45           0 :   const uint8_t* next_report_block = packet.payload() + kRrBaseLength;
      46             : 
      47           0 :   report_blocks_.resize(report_blocks_count);
      48           0 :   for (ReportBlock& block : report_blocks_) {
      49           0 :     block.Parse(next_report_block, ReportBlock::kLength);
      50           0 :     next_report_block += ReportBlock::kLength;
      51             :   }
      52             : 
      53           0 :   RTC_DCHECK_LE(next_report_block - packet.payload(),
      54           0 :                 static_cast<ptrdiff_t>(packet.payload_size_bytes()));
      55           0 :   return true;
      56             : }
      57             : 
      58           0 : bool ReceiverReport::Create(uint8_t* packet,
      59             :                             size_t* index,
      60             :                             size_t max_length,
      61             :                             RtcpPacket::PacketReadyCallback* callback) const {
      62           0 :   while (*index + BlockLength() > max_length) {
      63           0 :     if (!OnBufferFull(packet, index, callback))
      64           0 :       return false;
      65             :   }
      66           0 :   CreateHeader(report_blocks_.size(), kPacketType, HeaderLength(), packet,
      67           0 :                index);
      68           0 :   ByteWriter<uint32_t>::WriteBigEndian(packet + *index, sender_ssrc_);
      69           0 :   *index += kRrBaseLength;
      70           0 :   for (const ReportBlock& block : report_blocks_) {
      71           0 :     block.Create(packet + *index);
      72           0 :     *index += ReportBlock::kLength;
      73             :   }
      74           0 :   return true;
      75             : }
      76             : 
      77           0 : bool ReceiverReport::AddReportBlock(const ReportBlock& block) {
      78           0 :   if (report_blocks_.size() >= kMaxNumberOfReportBlocks) {
      79           0 :     LOG(LS_WARNING) << "Max report blocks reached.";
      80           0 :     return false;
      81             :   }
      82           0 :   report_blocks_.push_back(block);
      83           0 :   return true;
      84             : }
      85             : 
      86             : }  // namespace rtcp
      87             : }  // namespace webrtc