blob: 439cd01a9aa09c35ab2be30a03f1371be9280afe [file] [log] [blame]
/*
* Copyright (c) 2012 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 "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
#include <string.h>
#include "webrtc/base/logging.h"
#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
namespace webrtc {
RtpData* NullObjectRtpData() {
static NullRtpData null_rtp_data;
return &null_rtp_data;
}
RtpFeedback* NullObjectRtpFeedback() {
static NullRtpFeedback null_rtp_feedback;
return &null_rtp_feedback;
}
ReceiveStatistics* NullObjectReceiveStatistics() {
static NullReceiveStatistics null_receive_statistics;
return &null_receive_statistics;
}
namespace RtpUtility {
enum {
kRtcpExpectedVersion = 2,
kRtcpMinHeaderLength = 4,
kRtcpMinParseLength = 8,
kRtpExpectedVersion = 2,
kRtpMinParseLength = 12
};
/*
* Misc utility routines
*/
#if defined(_WIN32)
bool StringCompare(const char* str1, const char* str2,
const uint32_t length) {
return _strnicmp(str1, str2, length) == 0;
}
#elif defined(WEBRTC_LINUX) || defined(WEBRTC_MAC)
bool StringCompare(const char* str1, const char* str2,
const uint32_t length) {
return strncasecmp(str1, str2, length) == 0;
}
#endif
size_t Word32Align(size_t size) {
uint32_t remainder = size % 4;
if (remainder != 0)
return size + 4 - remainder;
return size;
}
RtpHeaderParser::RtpHeaderParser(const uint8_t* rtpData,
const size_t rtpDataLength)
: _ptrRTPDataBegin(rtpData),
_ptrRTPDataEnd(rtpData ? (rtpData + rtpDataLength) : NULL) {
}
RtpHeaderParser::~RtpHeaderParser() {
}
bool RtpHeaderParser::RTCP() const {
// 72 to 76 is reserved for RTP
// 77 to 79 is not reserver but they are not assigned we will block them
// for RTCP 200 SR == marker bit + 72
// for RTCP 204 APP == marker bit + 76
/*
* RTCP
*
* FIR full INTRA-frame request 192 [RFC2032] supported
* NACK negative acknowledgement 193 [RFC2032]
* IJ Extended inter-arrival jitter report 195 [RFC-ietf-avt-rtp-toff
* set-07.txt] http://tools.ietf.org/html/draft-ietf-avt-rtp-toffset-07
* SR sender report 200 [RFC3551] supported
* RR receiver report 201 [RFC3551] supported
* SDES source description 202 [RFC3551] supported
* BYE goodbye 203 [RFC3551] supported
* APP application-defined 204 [RFC3551] ignored
* RTPFB Transport layer FB message 205 [RFC4585] supported
* PSFB Payload-specific FB message 206 [RFC4585] supported
* XR extended report 207 [RFC3611] supported
*/
/* 205 RFC 5104
* FMT 1 NACK supported
* FMT 2 reserved
* FMT 3 TMMBR supported
* FMT 4 TMMBN supported
*/
/* 206 RFC 5104
* FMT 1: Picture Loss Indication (PLI) supported
* FMT 2: Slice Lost Indication (SLI)
* FMT 3: Reference Picture Selection Indication (RPSI)
* FMT 4: Full Intra Request (FIR) Command supported
* FMT 5: Temporal-Spatial Trade-off Request (TSTR)
* FMT 6: Temporal-Spatial Trade-off Notification (TSTN)
* FMT 7: Video Back Channel Message (VBCM)
* FMT 15: Application layer FB message
*/
const ptrdiff_t length = _ptrRTPDataEnd - _ptrRTPDataBegin;
if (length < kRtcpMinHeaderLength) {
return false;
}
const uint8_t V = _ptrRTPDataBegin[0] >> 6;
if (V != kRtcpExpectedVersion) {
return false;
}
const uint8_t payloadType = _ptrRTPDataBegin[1];
switch (payloadType) {
case 192:
return true;
case 193:
// not supported
// pass through and check for a potential RTP packet
return false;
case 195:
case 200:
case 201:
case 202:
case 203:
case 204:
case 205:
case 206:
case 207:
return true;
default:
return false;
}
}
bool RtpHeaderParser::ParseRtcp(RTPHeader* header) const {
assert(header != NULL);
const ptrdiff_t length = _ptrRTPDataEnd - _ptrRTPDataBegin;
if (length < kRtcpMinParseLength) {
return false;
}
const uint8_t V = _ptrRTPDataBegin[0] >> 6;
if (V != kRtcpExpectedVersion) {
return false;
}
const uint8_t PT = _ptrRTPDataBegin[1];
const size_t len = (_ptrRTPDataBegin[2] << 8) + _ptrRTPDataBegin[3];
const uint8_t* ptr = &_ptrRTPDataBegin[4];
uint32_t SSRC = ByteReader<uint32_t>::ReadBigEndian(ptr);
ptr += 4;
header->payloadType = PT;
header->ssrc = SSRC;
header->headerLength = 4 + (len << 2);
return true;
}
bool RtpHeaderParser::Parse(RTPHeader* header,
RtpHeaderExtensionMap* ptrExtensionMap) const {
const ptrdiff_t length = _ptrRTPDataEnd - _ptrRTPDataBegin;
if (length < kRtpMinParseLength) {
return false;
}
// Version
const uint8_t V = _ptrRTPDataBegin[0] >> 6;
// Padding
const bool P = ((_ptrRTPDataBegin[0] & 0x20) == 0) ? false : true;
// eXtension
const bool X = ((_ptrRTPDataBegin[0] & 0x10) == 0) ? false : true;
const uint8_t CC = _ptrRTPDataBegin[0] & 0x0f;
const bool M = ((_ptrRTPDataBegin[1] & 0x80) == 0) ? false : true;
const uint8_t PT = _ptrRTPDataBegin[1] & 0x7f;
const uint16_t sequenceNumber = (_ptrRTPDataBegin[2] << 8) +
_ptrRTPDataBegin[3];
const uint8_t* ptr = &_ptrRTPDataBegin[4];
uint32_t RTPTimestamp = ByteReader<uint32_t>::ReadBigEndian(ptr);
ptr += 4;
uint32_t SSRC = ByteReader<uint32_t>::ReadBigEndian(ptr);
ptr += 4;
if (V != kRtpExpectedVersion) {
return false;
}
const size_t CSRCocts = CC * 4;
if ((ptr + CSRCocts) > _ptrRTPDataEnd) {
return false;
}
header->markerBit = M;
header->payloadType = PT;
header->sequenceNumber = sequenceNumber;
header->timestamp = RTPTimestamp;
header->ssrc = SSRC;
header->numCSRCs = CC;
header->paddingLength = P ? *(_ptrRTPDataEnd - 1) : 0;
for (uint8_t i = 0; i < CC; ++i) {
uint32_t CSRC = ByteReader<uint32_t>::ReadBigEndian(ptr);
ptr += 4;
header->arrOfCSRCs[i] = CSRC;
}
header->headerLength = 12 + CSRCocts;
// If in effect, MAY be omitted for those packets for which the offset
// is zero.
header->extension.hasTransmissionTimeOffset = false;
header->extension.transmissionTimeOffset = 0;
// May not be present in packet.
header->extension.hasAbsoluteSendTime = false;
header->extension.absoluteSendTime = 0;
// May not be present in packet.
header->extension.hasAudioLevel = false;
header->extension.voiceActivity = false;
header->extension.audioLevel = 0;
// May not be present in packet.
header->extension.hasVideoRotation = false;
header->extension.videoRotation = 0;
if (X) {
/* RTP header extension, 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| defined by profile | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| header extension |
| .... |
*/
const ptrdiff_t remain = _ptrRTPDataEnd - ptr;
if (remain < 4) {
return false;
}
header->headerLength += 4;
uint16_t definedByProfile = ByteReader<uint16_t>::ReadBigEndian(ptr);
ptr += 2;
// in 32 bit words
size_t XLen = ByteReader<uint16_t>::ReadBigEndian(ptr);
ptr += 2;
XLen *= 4; // in bytes
if (static_cast<size_t>(remain) < (4 + XLen)) {
return false;
}
if (definedByProfile == kRtpOneByteHeaderExtensionId) {
const uint8_t* ptrRTPDataExtensionEnd = ptr + XLen;
ParseOneByteExtensionHeader(header,
ptrExtensionMap,
ptrRTPDataExtensionEnd,
ptr);
}
header->headerLength += XLen;
}
if (header->headerLength + header->paddingLength >
static_cast<size_t>(length))
return false;
return true;
}
void RtpHeaderParser::ParseOneByteExtensionHeader(
RTPHeader* header,
const RtpHeaderExtensionMap* ptrExtensionMap,
const uint8_t* ptrRTPDataExtensionEnd,
const uint8_t* ptr) const {
if (!ptrExtensionMap) {
return;
}
while (ptrRTPDataExtensionEnd - ptr > 0) {
// 0
// 0 1 2 3 4 5 6 7
// +-+-+-+-+-+-+-+-+
// | ID | len |
// +-+-+-+-+-+-+-+-+
// Note that 'len' is the header extension element length, which is the
// number of bytes - 1.
const int id = (*ptr & 0xf0) >> 4;
const int len = (*ptr & 0x0f);
ptr++;
if (id == 15) {
LOG(LS_WARNING)
<< "RTP extension header 15 encountered. Terminate parsing.";
return;
}
if (ptrRTPDataExtensionEnd - ptr < (len + 1)) {
LOG(LS_WARNING) << "Incorrect one-byte extension len: " << (len + 1)
<< ", bytes left in buffer: "
<< (ptrRTPDataExtensionEnd - ptr);
return;
}
RTPExtensionType type;
if (ptrExtensionMap->GetType(id, &type) != 0) {
// If we encounter an unknown extension, just skip over it.
LOG(LS_WARNING) << "Failed to find extension id: " << id;
} else {
switch (type) {
case kRtpExtensionTransmissionTimeOffset: {
if (len != 2) {
LOG(LS_WARNING) << "Incorrect transmission time offset len: "
<< len;
return;
}
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | ID | len=2 | transmission offset |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
header->extension.transmissionTimeOffset =
ByteReader<int32_t, 3>::ReadBigEndian(ptr);
header->extension.hasTransmissionTimeOffset = true;
break;
}
case kRtpExtensionAudioLevel: {
if (len != 0) {
LOG(LS_WARNING) << "Incorrect audio level len: " << len;
return;
}
// 0 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | ID | len=0 |V| level |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//
header->extension.audioLevel = ptr[0] & 0x7f;
header->extension.voiceActivity = (ptr[0] & 0x80) != 0;
header->extension.hasAudioLevel = true;
break;
}
case kRtpExtensionAbsoluteSendTime: {
if (len != 2) {
LOG(LS_WARNING) << "Incorrect absolute send time len: " << len;
return;
}
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | ID | len=2 | absolute send time |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
header->extension.absoluteSendTime =
ByteReader<uint32_t, 3>::ReadBigEndian(ptr);
header->extension.hasAbsoluteSendTime = true;
break;
}
case kRtpExtensionVideoRotation: {
if (len != 0) {
LOG(LS_WARNING)
<< "Incorrect coordination of video coordination len: " << len;
return;
}
// 0 1
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | ID | len=0 |0 0 0 0 C F R R|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
header->extension.hasVideoRotation = true;
header->extension.videoRotation = ptr[0];
break;
}
case kRtpExtensionTransportSequenceNumber: {
if (len != 1) {
LOG(LS_WARNING) << "Incorrect transport sequence number len: "
<< len;
return;
}
// 0 1 2
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | ID | L=1 |transport wide sequence number |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
uint16_t sequence_number = ptr[0] << 8;
sequence_number += ptr[1];
header->extension.transportSequenceNumber = sequence_number;
header->extension.hasTransportSequenceNumber = true;
break;
}
default: {
LOG(LS_WARNING) << "Extension type not implemented: " << type;
return;
}
}
}
ptr += (len + 1);
uint8_t num_bytes = ParsePaddingBytes(ptrRTPDataExtensionEnd, ptr);
ptr += num_bytes;
}
}
uint8_t RtpHeaderParser::ParsePaddingBytes(
const uint8_t* ptrRTPDataExtensionEnd,
const uint8_t* ptr) const {
uint8_t num_zero_bytes = 0;
while (ptrRTPDataExtensionEnd - ptr > 0) {
if (*ptr != 0) {
return num_zero_bytes;
}
ptr++;
num_zero_bytes++;
}
return num_zero_bytes;
}
} // namespace RtpUtility
} // namespace webrtc