1 /*
2 * Copyright (c) 2016 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 "modules/rtp_rtcp/source/rtcp_packet/extended_reports.h"
12
13 #include <vector>
14
15 #include "modules/rtp_rtcp/source/byte_io.h"
16 #include "modules/rtp_rtcp/source/rtcp_packet/common_header.h"
17 #include "rtc_base/checks.h"
18 #include "rtc_base/logging.h"
19
20 namespace webrtc {
21 namespace rtcp {
22 constexpr uint8_t ExtendedReports::kPacketType;
23 constexpr size_t ExtendedReports::kMaxNumberOfDlrrItems;
24 // From RFC 3611: RTP Control Protocol Extended Reports (RTCP XR).
25 //
26 // Format for XR packets:
27 //
28 // 0 1 2 3
29 // 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
30 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
31 // |V=2|P|reserved | PT=XR=207 | length |
32 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
33 // | SSRC |
34 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
35 // : report blocks :
36 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37 //
38 // Extended report block:
39 // 0 1 2 3
40 // 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
41 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 // | Block Type | reserved | block length |
43 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 // : type-specific block contents :
45 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 ExtendedReports::ExtendedReports() = default;
47 ExtendedReports::ExtendedReports(const ExtendedReports& xr) = default;
48 ExtendedReports::~ExtendedReports() = default;
49
Parse(const CommonHeader & packet)50 bool ExtendedReports::Parse(const CommonHeader& packet) {
51 RTC_DCHECK_EQ(packet.type(), kPacketType);
52
53 if (packet.payload_size_bytes() < kXrBaseLength) {
54 RTC_LOG(LS_WARNING)
55 << "Packet is too small to be an ExtendedReports packet.";
56 return false;
57 }
58
59 SetSenderSsrc(ByteReader<uint32_t>::ReadBigEndian(packet.payload()));
60 rrtr_block_.reset();
61 dlrr_block_.ClearItems();
62 target_bitrate_ = absl::nullopt;
63
64 const uint8_t* current_block = packet.payload() + kXrBaseLength;
65 const uint8_t* const packet_end =
66 packet.payload() + packet.payload_size_bytes();
67 constexpr size_t kBlockHeaderSizeBytes = 4;
68 while (current_block + kBlockHeaderSizeBytes <= packet_end) {
69 uint8_t block_type = ByteReader<uint8_t>::ReadBigEndian(current_block);
70 uint16_t block_length =
71 ByteReader<uint16_t>::ReadBigEndian(current_block + 2);
72 const uint8_t* next_block =
73 current_block + kBlockHeaderSizeBytes + block_length * 4;
74 if (next_block > packet_end) {
75 RTC_LOG(LS_WARNING)
76 << "Report block in extended report packet is too big.";
77 return false;
78 }
79 switch (block_type) {
80 case Rrtr::kBlockType:
81 ParseRrtrBlock(current_block, block_length);
82 break;
83 case Dlrr::kBlockType:
84 ParseDlrrBlock(current_block, block_length);
85 break;
86 case TargetBitrate::kBlockType:
87 ParseTargetBitrateBlock(current_block, block_length);
88 break;
89 default:
90 // Unknown block, ignore.
91 RTC_LOG(LS_WARNING)
92 << "Unknown extended report block type " << block_type;
93 break;
94 }
95 current_block = next_block;
96 }
97
98 return true;
99 }
100
SetRrtr(const Rrtr & rrtr)101 void ExtendedReports::SetRrtr(const Rrtr& rrtr) {
102 if (rrtr_block_)
103 RTC_LOG(LS_WARNING) << "Rrtr already set, overwriting.";
104 rrtr_block_.emplace(rrtr);
105 }
106
AddDlrrItem(const ReceiveTimeInfo & time_info)107 bool ExtendedReports::AddDlrrItem(const ReceiveTimeInfo& time_info) {
108 if (dlrr_block_.sub_blocks().size() >= kMaxNumberOfDlrrItems) {
109 RTC_LOG(LS_WARNING) << "Reached maximum number of DLRR items.";
110 return false;
111 }
112 dlrr_block_.AddDlrrItem(time_info);
113 return true;
114 }
115
SetTargetBitrate(const TargetBitrate & bitrate)116 void ExtendedReports::SetTargetBitrate(const TargetBitrate& bitrate) {
117 if (target_bitrate_)
118 RTC_LOG(LS_WARNING) << "TargetBitrate already set, overwriting.";
119
120 target_bitrate_ = bitrate;
121 }
122
BlockLength() const123 size_t ExtendedReports::BlockLength() const {
124 return kHeaderLength + kXrBaseLength + RrtrLength() + DlrrLength() +
125 TargetBitrateLength();
126 }
127
Create(uint8_t * packet,size_t * index,size_t max_length,PacketReadyCallback callback) const128 bool ExtendedReports::Create(uint8_t* packet,
129 size_t* index,
130 size_t max_length,
131 PacketReadyCallback callback) const {
132 while (*index + BlockLength() > max_length) {
133 if (!OnBufferFull(packet, index, callback))
134 return false;
135 }
136 size_t index_end = *index + BlockLength();
137 const uint8_t kReserved = 0;
138 CreateHeader(kReserved, kPacketType, HeaderLength(), packet, index);
139 ByteWriter<uint32_t>::WriteBigEndian(packet + *index, sender_ssrc());
140 *index += sizeof(uint32_t);
141 if (rrtr_block_) {
142 rrtr_block_->Create(packet + *index);
143 *index += Rrtr::kLength;
144 }
145 if (dlrr_block_) {
146 dlrr_block_.Create(packet + *index);
147 *index += dlrr_block_.BlockLength();
148 }
149 if (target_bitrate_) {
150 target_bitrate_->Create(packet + *index);
151 *index += target_bitrate_->BlockLength();
152 }
153 RTC_CHECK_EQ(*index, index_end);
154 return true;
155 }
156
TargetBitrateLength() const157 size_t ExtendedReports::TargetBitrateLength() const {
158 if (target_bitrate_)
159 return target_bitrate_->BlockLength();
160 return 0;
161 }
162
ParseRrtrBlock(const uint8_t * block,uint16_t block_length)163 void ExtendedReports::ParseRrtrBlock(const uint8_t* block,
164 uint16_t block_length) {
165 if (block_length != Rrtr::kBlockLength) {
166 RTC_LOG(LS_WARNING) << "Incorrect rrtr block size " << block_length
167 << " Should be " << Rrtr::kBlockLength;
168 return;
169 }
170 if (rrtr_block_) {
171 RTC_LOG(LS_WARNING)
172 << "Two rrtr blocks found in same Extended Report packet";
173 return;
174 }
175 rrtr_block_.emplace();
176 rrtr_block_->Parse(block);
177 }
178
ParseDlrrBlock(const uint8_t * block,uint16_t block_length)179 void ExtendedReports::ParseDlrrBlock(const uint8_t* block,
180 uint16_t block_length) {
181 if (dlrr_block_) {
182 RTC_LOG(LS_WARNING)
183 << "Two Dlrr blocks found in same Extended Report packet";
184 return;
185 }
186 dlrr_block_.Parse(block, block_length);
187 }
188
ParseTargetBitrateBlock(const uint8_t * block,uint16_t block_length)189 void ExtendedReports::ParseTargetBitrateBlock(const uint8_t* block,
190 uint16_t block_length) {
191 target_bitrate_.emplace();
192 target_bitrate_->Parse(block, block_length);
193 }
194 } // namespace rtcp
195 } // namespace webrtc
196