696 lines
26 KiB
C++
696 lines
26 KiB
C++
/*
|
|
* 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/rtp_packet.h"
|
|
|
|
#include <cstdint>
|
|
#include <cstring>
|
|
#include <utility>
|
|
|
|
#include "modules/rtp_rtcp/source/byte_io.h"
|
|
#include "modules/rtp_rtcp/source/rtp_header_extensions.h"
|
|
#include "rtc_base/checks.h"
|
|
#include "rtc_base/logging.h"
|
|
#include "rtc_base/numerics/safe_conversions.h"
|
|
#include "rtc_base/strings/string_builder.h"
|
|
|
|
namespace webrtc {
|
|
namespace {
|
|
constexpr size_t kFixedHeaderSize = 12;
|
|
constexpr uint8_t kRtpVersion = 2;
|
|
constexpr uint16_t kOneByteExtensionProfileId = 0xBEDE;
|
|
constexpr uint16_t kTwoByteExtensionProfileId = 0x1000;
|
|
constexpr size_t kOneByteExtensionHeaderLength = 1;
|
|
constexpr size_t kTwoByteExtensionHeaderLength = 2;
|
|
constexpr size_t kDefaultPacketSize = 1500;
|
|
} // namespace
|
|
|
|
// 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|X| CC |M| PT | sequence number |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | timestamp |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | synchronization source (SSRC) identifier |
|
|
// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
|
|
// | Contributing source (CSRC) identifiers |
|
|
// | .... |
|
|
// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
|
|
// | header eXtension profile id | length in 32bits |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | Extensions |
|
|
// | .... |
|
|
// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
|
|
// | Payload |
|
|
// | .... : padding... |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | padding | Padding size |
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
RtpPacket::RtpPacket() : RtpPacket(nullptr, kDefaultPacketSize) {}
|
|
|
|
RtpPacket::RtpPacket(const ExtensionManager* extensions)
|
|
: RtpPacket(extensions, kDefaultPacketSize) {}
|
|
|
|
RtpPacket::RtpPacket(const RtpPacket&) = default;
|
|
|
|
RtpPacket::RtpPacket(const ExtensionManager* extensions, size_t capacity)
|
|
: extensions_(extensions ? *extensions : ExtensionManager()),
|
|
buffer_(capacity) {
|
|
RTC_DCHECK_GE(capacity, kFixedHeaderSize);
|
|
Clear();
|
|
}
|
|
|
|
RtpPacket::~RtpPacket() {}
|
|
|
|
void RtpPacket::IdentifyExtensions(const ExtensionManager& extensions) {
|
|
extensions_ = extensions;
|
|
}
|
|
|
|
bool RtpPacket::Parse(const uint8_t* buffer, size_t buffer_size) {
|
|
if (!ParseBuffer(buffer, buffer_size)) {
|
|
Clear();
|
|
return false;
|
|
}
|
|
buffer_.SetData(buffer, buffer_size);
|
|
RTC_DCHECK_EQ(size(), buffer_size);
|
|
return true;
|
|
}
|
|
|
|
bool RtpPacket::Parse(rtc::ArrayView<const uint8_t> packet) {
|
|
return Parse(packet.data(), packet.size());
|
|
}
|
|
|
|
bool RtpPacket::Parse(rtc::CopyOnWriteBuffer buffer) {
|
|
if (!ParseBuffer(buffer.cdata(), buffer.size())) {
|
|
Clear();
|
|
return false;
|
|
}
|
|
size_t buffer_size = buffer.size();
|
|
buffer_ = std::move(buffer);
|
|
RTC_DCHECK_EQ(size(), buffer_size);
|
|
return true;
|
|
}
|
|
|
|
std::vector<uint32_t> RtpPacket::Csrcs() const {
|
|
size_t num_csrc = data()[0] & 0x0F;
|
|
RTC_DCHECK_GE(capacity(), kFixedHeaderSize + num_csrc * 4);
|
|
std::vector<uint32_t> csrcs(num_csrc);
|
|
for (size_t i = 0; i < num_csrc; ++i) {
|
|
csrcs[i] =
|
|
ByteReader<uint32_t>::ReadBigEndian(&data()[kFixedHeaderSize + i * 4]);
|
|
}
|
|
return csrcs;
|
|
}
|
|
|
|
void RtpPacket::CopyHeaderFrom(const RtpPacket& packet) {
|
|
RTC_DCHECK_GE(capacity(), packet.headers_size());
|
|
|
|
marker_ = packet.marker_;
|
|
payload_type_ = packet.payload_type_;
|
|
sequence_number_ = packet.sequence_number_;
|
|
timestamp_ = packet.timestamp_;
|
|
ssrc_ = packet.ssrc_;
|
|
payload_offset_ = packet.payload_offset_;
|
|
extensions_ = packet.extensions_;
|
|
extension_entries_ = packet.extension_entries_;
|
|
extensions_size_ = packet.extensions_size_;
|
|
buffer_ = packet.buffer_.Slice(0, packet.headers_size());
|
|
// Reset payload and padding.
|
|
payload_size_ = 0;
|
|
padding_size_ = 0;
|
|
}
|
|
|
|
void RtpPacket::SetMarker(bool marker_bit) {
|
|
marker_ = marker_bit;
|
|
if (marker_) {
|
|
WriteAt(1, data()[1] | 0x80);
|
|
} else {
|
|
WriteAt(1, data()[1] & 0x7F);
|
|
}
|
|
}
|
|
|
|
void RtpPacket::SetPayloadType(uint8_t payload_type) {
|
|
RTC_DCHECK_LE(payload_type, 0x7Fu);
|
|
payload_type_ = payload_type;
|
|
WriteAt(1, (data()[1] & 0x80) | payload_type);
|
|
}
|
|
|
|
void RtpPacket::SetSequenceNumber(uint16_t seq_no) {
|
|
sequence_number_ = seq_no;
|
|
ByteWriter<uint16_t>::WriteBigEndian(WriteAt(2), seq_no);
|
|
}
|
|
|
|
void RtpPacket::SetTimestamp(uint32_t timestamp) {
|
|
timestamp_ = timestamp;
|
|
ByteWriter<uint32_t>::WriteBigEndian(WriteAt(4), timestamp);
|
|
}
|
|
|
|
void RtpPacket::SetSsrc(uint32_t ssrc) {
|
|
ssrc_ = ssrc;
|
|
ByteWriter<uint32_t>::WriteBigEndian(WriteAt(8), ssrc);
|
|
}
|
|
|
|
void RtpPacket::ZeroMutableExtensions() {
|
|
for (const ExtensionInfo& extension : extension_entries_) {
|
|
switch (extensions_.GetType(extension.id)) {
|
|
case RTPExtensionType::kRtpExtensionNone: {
|
|
RTC_LOG(LS_WARNING) << "Unidentified extension in the packet.";
|
|
break;
|
|
}
|
|
case RTPExtensionType::kRtpExtensionVideoTiming: {
|
|
// Nullify last entries, starting at pacer delay.
|
|
// These are set by pacer and SFUs
|
|
if (VideoTimingExtension::kPacerExitDeltaOffset < extension.length) {
|
|
memset(
|
|
WriteAt(extension.offset +
|
|
VideoTimingExtension::kPacerExitDeltaOffset),
|
|
0,
|
|
extension.length - VideoTimingExtension::kPacerExitDeltaOffset);
|
|
}
|
|
break;
|
|
}
|
|
case RTPExtensionType::kRtpExtensionTransportSequenceNumber:
|
|
case RTPExtensionType::kRtpExtensionTransportSequenceNumber02:
|
|
case RTPExtensionType::kRtpExtensionTransmissionTimeOffset:
|
|
case RTPExtensionType::kRtpExtensionAbsoluteSendTime: {
|
|
// Nullify whole extension, as it's filled in the pacer.
|
|
memset(WriteAt(extension.offset), 0, extension.length);
|
|
break;
|
|
}
|
|
case RTPExtensionType::kRtpExtensionAudioLevel:
|
|
case RTPExtensionType::kRtpExtensionAbsoluteCaptureTime:
|
|
case RTPExtensionType::kRtpExtensionColorSpace:
|
|
case RTPExtensionType::kRtpExtensionGenericFrameDescriptor00:
|
|
case RTPExtensionType::kRtpExtensionGenericFrameDescriptor02:
|
|
case RTPExtensionType::kRtpExtensionMid:
|
|
case RTPExtensionType::kRtpExtensionNumberOfExtensions:
|
|
case RTPExtensionType::kRtpExtensionPlayoutDelay:
|
|
case RTPExtensionType::kRtpExtensionRepairedRtpStreamId:
|
|
case RTPExtensionType::kRtpExtensionRtpStreamId:
|
|
case RTPExtensionType::kRtpExtensionVideoContentType:
|
|
case RTPExtensionType::kRtpExtensionVideoRotation:
|
|
case RTPExtensionType::kRtpExtensionInbandComfortNoise: {
|
|
// Non-mutable extension. Don't change it.
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void RtpPacket::SetCsrcs(rtc::ArrayView<const uint32_t> csrcs) {
|
|
RTC_DCHECK_EQ(extensions_size_, 0);
|
|
RTC_DCHECK_EQ(payload_size_, 0);
|
|
RTC_DCHECK_EQ(padding_size_, 0);
|
|
RTC_DCHECK_LE(csrcs.size(), 0x0fu);
|
|
RTC_DCHECK_LE(kFixedHeaderSize + 4 * csrcs.size(), capacity());
|
|
payload_offset_ = kFixedHeaderSize + 4 * csrcs.size();
|
|
WriteAt(0, (data()[0] & 0xF0) | rtc::dchecked_cast<uint8_t>(csrcs.size()));
|
|
size_t offset = kFixedHeaderSize;
|
|
for (uint32_t csrc : csrcs) {
|
|
ByteWriter<uint32_t>::WriteBigEndian(WriteAt(offset), csrc);
|
|
offset += 4;
|
|
}
|
|
buffer_.SetSize(payload_offset_);
|
|
}
|
|
|
|
rtc::ArrayView<uint8_t> RtpPacket::AllocateRawExtension(int id, size_t length) {
|
|
RTC_DCHECK_GE(id, RtpExtension::kMinId);
|
|
RTC_DCHECK_LE(id, RtpExtension::kMaxId);
|
|
RTC_DCHECK_GE(length, 1);
|
|
RTC_DCHECK_LE(length, RtpExtension::kMaxValueSize);
|
|
const ExtensionInfo* extension_entry = FindExtensionInfo(id);
|
|
if (extension_entry != nullptr) {
|
|
// Extension already reserved. Check if same length is used.
|
|
if (extension_entry->length == length)
|
|
return rtc::MakeArrayView(WriteAt(extension_entry->offset), length);
|
|
|
|
RTC_LOG(LS_ERROR) << "Length mismatch for extension id " << id
|
|
<< ": expected "
|
|
<< static_cast<int>(extension_entry->length)
|
|
<< ". received " << length;
|
|
return nullptr;
|
|
}
|
|
if (payload_size_ > 0) {
|
|
RTC_LOG(LS_ERROR) << "Can't add new extension id " << id
|
|
<< " after payload was set.";
|
|
return nullptr;
|
|
}
|
|
if (padding_size_ > 0) {
|
|
RTC_LOG(LS_ERROR) << "Can't add new extension id " << id
|
|
<< " after padding was set.";
|
|
return nullptr;
|
|
}
|
|
|
|
const size_t num_csrc = data()[0] & 0x0F;
|
|
const size_t extensions_offset = kFixedHeaderSize + (num_csrc * 4) + 4;
|
|
// Determine if two-byte header is required for the extension based on id and
|
|
// length. Please note that a length of 0 also requires two-byte header
|
|
// extension. See RFC8285 Section 4.2-4.3.
|
|
const bool two_byte_header_required =
|
|
id > RtpExtension::kOneByteHeaderExtensionMaxId ||
|
|
length > RtpExtension::kOneByteHeaderExtensionMaxValueSize || length == 0;
|
|
RTC_CHECK(!two_byte_header_required || extensions_.ExtmapAllowMixed());
|
|
|
|
uint16_t profile_id;
|
|
if (extensions_size_ > 0) {
|
|
profile_id =
|
|
ByteReader<uint16_t>::ReadBigEndian(data() + extensions_offset - 4);
|
|
if (profile_id == kOneByteExtensionProfileId && two_byte_header_required) {
|
|
// Is buffer size big enough to fit promotion and new data field?
|
|
// The header extension will grow with one byte per already allocated
|
|
// extension + the size of the extension that is about to be allocated.
|
|
size_t expected_new_extensions_size =
|
|
extensions_size_ + extension_entries_.size() +
|
|
kTwoByteExtensionHeaderLength + length;
|
|
if (extensions_offset + expected_new_extensions_size > capacity()) {
|
|
RTC_LOG(LS_ERROR)
|
|
<< "Extension cannot be registered: Not enough space left in "
|
|
"buffer to change to two-byte header extension and add new "
|
|
"extension.";
|
|
return nullptr;
|
|
}
|
|
// Promote already written data to two-byte header format.
|
|
PromoteToTwoByteHeaderExtension();
|
|
profile_id = kTwoByteExtensionProfileId;
|
|
}
|
|
} else {
|
|
// Profile specific ID, set to OneByteExtensionHeader unless
|
|
// TwoByteExtensionHeader is required.
|
|
profile_id = two_byte_header_required ? kTwoByteExtensionProfileId
|
|
: kOneByteExtensionProfileId;
|
|
}
|
|
|
|
const size_t extension_header_size = profile_id == kOneByteExtensionProfileId
|
|
? kOneByteExtensionHeaderLength
|
|
: kTwoByteExtensionHeaderLength;
|
|
size_t new_extensions_size =
|
|
extensions_size_ + extension_header_size + length;
|
|
if (extensions_offset + new_extensions_size > capacity()) {
|
|
RTC_LOG(LS_ERROR)
|
|
<< "Extension cannot be registered: Not enough space left in buffer.";
|
|
return nullptr;
|
|
}
|
|
|
|
// All checks passed, write down the extension headers.
|
|
if (extensions_size_ == 0) {
|
|
RTC_DCHECK_EQ(payload_offset_, kFixedHeaderSize + (num_csrc * 4));
|
|
WriteAt(0, data()[0] | 0x10); // Set extension bit.
|
|
ByteWriter<uint16_t>::WriteBigEndian(WriteAt(extensions_offset - 4),
|
|
profile_id);
|
|
}
|
|
|
|
if (profile_id == kOneByteExtensionProfileId) {
|
|
uint8_t one_byte_header = rtc::dchecked_cast<uint8_t>(id) << 4;
|
|
one_byte_header |= rtc::dchecked_cast<uint8_t>(length - 1);
|
|
WriteAt(extensions_offset + extensions_size_, one_byte_header);
|
|
} else {
|
|
// TwoByteHeaderExtension.
|
|
uint8_t extension_id = rtc::dchecked_cast<uint8_t>(id);
|
|
WriteAt(extensions_offset + extensions_size_, extension_id);
|
|
uint8_t extension_length = rtc::dchecked_cast<uint8_t>(length);
|
|
WriteAt(extensions_offset + extensions_size_ + 1, extension_length);
|
|
}
|
|
|
|
const uint16_t extension_info_offset = rtc::dchecked_cast<uint16_t>(
|
|
extensions_offset + extensions_size_ + extension_header_size);
|
|
const uint8_t extension_info_length = rtc::dchecked_cast<uint8_t>(length);
|
|
extension_entries_.emplace_back(id, extension_info_length,
|
|
extension_info_offset);
|
|
|
|
extensions_size_ = new_extensions_size;
|
|
|
|
uint16_t extensions_size_padded =
|
|
SetExtensionLengthMaybeAddZeroPadding(extensions_offset);
|
|
payload_offset_ = extensions_offset + extensions_size_padded;
|
|
buffer_.SetSize(payload_offset_);
|
|
return rtc::MakeArrayView(WriteAt(extension_info_offset),
|
|
extension_info_length);
|
|
}
|
|
|
|
void RtpPacket::PromoteToTwoByteHeaderExtension() {
|
|
size_t num_csrc = data()[0] & 0x0F;
|
|
size_t extensions_offset = kFixedHeaderSize + (num_csrc * 4) + 4;
|
|
|
|
RTC_CHECK_GT(extension_entries_.size(), 0);
|
|
RTC_CHECK_EQ(payload_size_, 0);
|
|
RTC_CHECK_EQ(kOneByteExtensionProfileId, ByteReader<uint16_t>::ReadBigEndian(
|
|
data() + extensions_offset - 4));
|
|
// Rewrite data.
|
|
// Each extension adds one to the offset. The write-read delta for the last
|
|
// extension is therefore the same as the number of extension entries.
|
|
size_t write_read_delta = extension_entries_.size();
|
|
for (auto extension_entry = extension_entries_.rbegin();
|
|
extension_entry != extension_entries_.rend(); ++extension_entry) {
|
|
size_t read_index = extension_entry->offset;
|
|
size_t write_index = read_index + write_read_delta;
|
|
// Update offset.
|
|
extension_entry->offset = rtc::dchecked_cast<uint16_t>(write_index);
|
|
// Copy data. Use memmove since read/write regions may overlap.
|
|
memmove(WriteAt(write_index), data() + read_index, extension_entry->length);
|
|
// Rewrite id and length.
|
|
WriteAt(--write_index, extension_entry->length);
|
|
WriteAt(--write_index, extension_entry->id);
|
|
--write_read_delta;
|
|
}
|
|
|
|
// Update profile header, extensions length, and zero padding.
|
|
ByteWriter<uint16_t>::WriteBigEndian(WriteAt(extensions_offset - 4),
|
|
kTwoByteExtensionProfileId);
|
|
extensions_size_ += extension_entries_.size();
|
|
uint16_t extensions_size_padded =
|
|
SetExtensionLengthMaybeAddZeroPadding(extensions_offset);
|
|
payload_offset_ = extensions_offset + extensions_size_padded;
|
|
buffer_.SetSize(payload_offset_);
|
|
}
|
|
|
|
uint16_t RtpPacket::SetExtensionLengthMaybeAddZeroPadding(
|
|
size_t extensions_offset) {
|
|
// Update header length field.
|
|
uint16_t extensions_words = rtc::dchecked_cast<uint16_t>(
|
|
(extensions_size_ + 3) / 4); // Wrap up to 32bit.
|
|
ByteWriter<uint16_t>::WriteBigEndian(WriteAt(extensions_offset - 2),
|
|
extensions_words);
|
|
// Fill extension padding place with zeroes.
|
|
size_t extension_padding_size = 4 * extensions_words - extensions_size_;
|
|
memset(WriteAt(extensions_offset + extensions_size_), 0,
|
|
extension_padding_size);
|
|
return 4 * extensions_words;
|
|
}
|
|
|
|
uint8_t* RtpPacket::AllocatePayload(size_t size_bytes) {
|
|
// Reset payload size to 0. If CopyOnWrite buffer_ was shared, this will cause
|
|
// reallocation and memcpy. Keeping just header reduces memcpy size.
|
|
SetPayloadSize(0);
|
|
return SetPayloadSize(size_bytes);
|
|
}
|
|
|
|
uint8_t* RtpPacket::SetPayloadSize(size_t size_bytes) {
|
|
RTC_DCHECK_EQ(padding_size_, 0);
|
|
if (payload_offset_ + size_bytes > capacity()) {
|
|
RTC_LOG(LS_WARNING) << "Cannot set payload, not enough space in buffer.";
|
|
return nullptr;
|
|
}
|
|
payload_size_ = size_bytes;
|
|
buffer_.SetSize(payload_offset_ + payload_size_);
|
|
return WriteAt(payload_offset_);
|
|
}
|
|
|
|
bool RtpPacket::SetPadding(size_t padding_bytes) {
|
|
if (payload_offset_ + payload_size_ + padding_bytes > capacity()) {
|
|
RTC_LOG(LS_WARNING) << "Cannot set padding size " << padding_bytes
|
|
<< ", only "
|
|
<< (capacity() - payload_offset_ - payload_size_)
|
|
<< " bytes left in buffer.";
|
|
return false;
|
|
}
|
|
padding_size_ = rtc::dchecked_cast<uint8_t>(padding_bytes);
|
|
buffer_.SetSize(payload_offset_ + payload_size_ + padding_size_);
|
|
if (padding_size_ > 0) {
|
|
size_t padding_offset = payload_offset_ + payload_size_;
|
|
size_t padding_end = padding_offset + padding_size_;
|
|
memset(WriteAt(padding_offset), 0, padding_size_ - 1);
|
|
WriteAt(padding_end - 1, padding_size_);
|
|
WriteAt(0, data()[0] | 0x20); // Set padding bit.
|
|
} else {
|
|
WriteAt(0, data()[0] & ~0x20); // Clear padding bit.
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void RtpPacket::Clear() {
|
|
marker_ = false;
|
|
payload_type_ = 0;
|
|
sequence_number_ = 0;
|
|
timestamp_ = 0;
|
|
ssrc_ = 0;
|
|
payload_offset_ = kFixedHeaderSize;
|
|
payload_size_ = 0;
|
|
padding_size_ = 0;
|
|
extensions_size_ = 0;
|
|
extension_entries_.clear();
|
|
|
|
memset(WriteAt(0), 0, kFixedHeaderSize);
|
|
buffer_.SetSize(kFixedHeaderSize);
|
|
WriteAt(0, kRtpVersion << 6);
|
|
}
|
|
|
|
bool RtpPacket::ParseBuffer(const uint8_t* buffer, size_t size) {
|
|
if (size < kFixedHeaderSize) {
|
|
return false;
|
|
}
|
|
const uint8_t version = buffer[0] >> 6;
|
|
if (version != kRtpVersion) {
|
|
return false;
|
|
}
|
|
const bool has_padding = (buffer[0] & 0x20) != 0;
|
|
const bool has_extension = (buffer[0] & 0x10) != 0;
|
|
const uint8_t number_of_crcs = buffer[0] & 0x0f;
|
|
marker_ = (buffer[1] & 0x80) != 0;
|
|
payload_type_ = buffer[1] & 0x7f;
|
|
|
|
sequence_number_ = ByteReader<uint16_t>::ReadBigEndian(&buffer[2]);
|
|
timestamp_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[4]);
|
|
ssrc_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[8]);
|
|
if (size < kFixedHeaderSize + number_of_crcs * 4) {
|
|
return false;
|
|
}
|
|
payload_offset_ = kFixedHeaderSize + number_of_crcs * 4;
|
|
|
|
if (has_padding) {
|
|
padding_size_ = buffer[size - 1];
|
|
if (padding_size_ == 0) {
|
|
RTC_LOG(LS_WARNING) << "Padding was set, but padding size is zero";
|
|
return false;
|
|
}
|
|
} else {
|
|
padding_size_ = 0;
|
|
}
|
|
|
|
extensions_size_ = 0;
|
|
extension_entries_.clear();
|
|
if (has_extension) {
|
|
/* 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 |
|
|
| .... |
|
|
*/
|
|
size_t extension_offset = payload_offset_ + 4;
|
|
if (extension_offset > size) {
|
|
return false;
|
|
}
|
|
uint16_t profile =
|
|
ByteReader<uint16_t>::ReadBigEndian(&buffer[payload_offset_]);
|
|
size_t extensions_capacity =
|
|
ByteReader<uint16_t>::ReadBigEndian(&buffer[payload_offset_ + 2]);
|
|
extensions_capacity *= 4;
|
|
if (extension_offset + extensions_capacity > size) {
|
|
return false;
|
|
}
|
|
if (profile != kOneByteExtensionProfileId &&
|
|
profile != kTwoByteExtensionProfileId) {
|
|
RTC_LOG(LS_WARNING) << "Unsupported rtp extension " << profile;
|
|
} else {
|
|
size_t extension_header_length = profile == kOneByteExtensionProfileId
|
|
? kOneByteExtensionHeaderLength
|
|
: kTwoByteExtensionHeaderLength;
|
|
constexpr uint8_t kPaddingByte = 0;
|
|
constexpr uint8_t kPaddingId = 0;
|
|
constexpr uint8_t kOneByteHeaderExtensionReservedId = 15;
|
|
while (extensions_size_ + extension_header_length < extensions_capacity) {
|
|
if (buffer[extension_offset + extensions_size_] == kPaddingByte) {
|
|
extensions_size_++;
|
|
continue;
|
|
}
|
|
int id;
|
|
uint8_t length;
|
|
if (profile == kOneByteExtensionProfileId) {
|
|
id = buffer[extension_offset + extensions_size_] >> 4;
|
|
length = 1 + (buffer[extension_offset + extensions_size_] & 0xf);
|
|
if (id == kOneByteHeaderExtensionReservedId ||
|
|
(id == kPaddingId && length != 1)) {
|
|
break;
|
|
}
|
|
} else {
|
|
id = buffer[extension_offset + extensions_size_];
|
|
length = buffer[extension_offset + extensions_size_ + 1];
|
|
}
|
|
|
|
if (extensions_size_ + extension_header_length + length >
|
|
extensions_capacity) {
|
|
RTC_LOG(LS_WARNING) << "Oversized rtp header extension.";
|
|
break;
|
|
}
|
|
|
|
ExtensionInfo& extension_info = FindOrCreateExtensionInfo(id);
|
|
if (extension_info.length != 0) {
|
|
RTC_LOG(LS_VERBOSE)
|
|
<< "Duplicate rtp header extension id " << id << ". Overwriting.";
|
|
}
|
|
|
|
size_t offset =
|
|
extension_offset + extensions_size_ + extension_header_length;
|
|
if (!rtc::IsValueInRangeForNumericType<uint16_t>(offset)) {
|
|
RTC_DLOG(LS_WARNING) << "Oversized rtp header extension.";
|
|
break;
|
|
}
|
|
extension_info.offset = static_cast<uint16_t>(offset);
|
|
extension_info.length = length;
|
|
extensions_size_ += extension_header_length + length;
|
|
}
|
|
}
|
|
payload_offset_ = extension_offset + extensions_capacity;
|
|
}
|
|
|
|
if (payload_offset_ + padding_size_ > size) {
|
|
return false;
|
|
}
|
|
payload_size_ = size - payload_offset_ - padding_size_;
|
|
return true;
|
|
}
|
|
|
|
const RtpPacket::ExtensionInfo* RtpPacket::FindExtensionInfo(int id) const {
|
|
for (const ExtensionInfo& extension : extension_entries_) {
|
|
if (extension.id == id) {
|
|
return &extension;
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
RtpPacket::ExtensionInfo& RtpPacket::FindOrCreateExtensionInfo(int id) {
|
|
for (ExtensionInfo& extension : extension_entries_) {
|
|
if (extension.id == id) {
|
|
return extension;
|
|
}
|
|
}
|
|
extension_entries_.emplace_back(id);
|
|
return extension_entries_.back();
|
|
}
|
|
|
|
rtc::ArrayView<const uint8_t> RtpPacket::FindExtension(
|
|
ExtensionType type) const {
|
|
uint8_t id = extensions_.GetId(type);
|
|
if (id == ExtensionManager::kInvalidId) {
|
|
// Extension not registered.
|
|
return nullptr;
|
|
}
|
|
ExtensionInfo const* extension_info = FindExtensionInfo(id);
|
|
if (extension_info == nullptr) {
|
|
return nullptr;
|
|
}
|
|
return rtc::MakeArrayView(data() + extension_info->offset,
|
|
extension_info->length);
|
|
}
|
|
|
|
rtc::ArrayView<uint8_t> RtpPacket::AllocateExtension(ExtensionType type,
|
|
size_t length) {
|
|
// TODO(webrtc:7990): Add support for empty extensions (length==0).
|
|
if (length == 0 || length > RtpExtension::kMaxValueSize ||
|
|
(!extensions_.ExtmapAllowMixed() &&
|
|
length > RtpExtension::kOneByteHeaderExtensionMaxValueSize)) {
|
|
return nullptr;
|
|
}
|
|
|
|
uint8_t id = extensions_.GetId(type);
|
|
if (id == ExtensionManager::kInvalidId) {
|
|
// Extension not registered.
|
|
return nullptr;
|
|
}
|
|
if (!extensions_.ExtmapAllowMixed() &&
|
|
id > RtpExtension::kOneByteHeaderExtensionMaxId) {
|
|
return nullptr;
|
|
}
|
|
return AllocateRawExtension(id, length);
|
|
}
|
|
|
|
bool RtpPacket::HasExtension(ExtensionType type) const {
|
|
uint8_t id = extensions_.GetId(type);
|
|
if (id == ExtensionManager::kInvalidId) {
|
|
// Extension not registered.
|
|
return false;
|
|
}
|
|
return FindExtensionInfo(id) != nullptr;
|
|
}
|
|
|
|
bool RtpPacket::RemoveExtension(ExtensionType type) {
|
|
uint8_t id_to_remove = extensions_.GetId(type);
|
|
if (id_to_remove == ExtensionManager::kInvalidId) {
|
|
// Extension not registered.
|
|
RTC_LOG(LS_ERROR) << "Extension not registered, type=" << type
|
|
<< ", packet=" << ToString();
|
|
return false;
|
|
}
|
|
|
|
// Rebuild new packet from scratch.
|
|
RtpPacket new_packet;
|
|
|
|
new_packet.SetMarker(Marker());
|
|
new_packet.SetPayloadType(PayloadType());
|
|
new_packet.SetSequenceNumber(SequenceNumber());
|
|
new_packet.SetTimestamp(Timestamp());
|
|
new_packet.SetSsrc(Ssrc());
|
|
new_packet.IdentifyExtensions(extensions_);
|
|
|
|
// Copy all extensions, except the one we are removing.
|
|
bool found_extension = false;
|
|
for (const ExtensionInfo& ext : extension_entries_) {
|
|
if (ext.id == id_to_remove) {
|
|
found_extension = true;
|
|
} else {
|
|
auto extension_data = new_packet.AllocateRawExtension(ext.id, ext.length);
|
|
if (extension_data.size() != ext.length) {
|
|
RTC_LOG(LS_ERROR) << "Failed to allocate extension id=" << ext.id
|
|
<< ", length=" << ext.length
|
|
<< ", packet=" << ToString();
|
|
return false;
|
|
}
|
|
|
|
// Copy extension data to new packet.
|
|
memcpy(extension_data.data(), ReadAt(ext.offset), ext.length);
|
|
}
|
|
}
|
|
|
|
if (!found_extension) {
|
|
RTC_LOG(LS_WARNING) << "Extension not present in RTP packet, type=" << type
|
|
<< ", packet=" << ToString();
|
|
return false;
|
|
}
|
|
|
|
// Copy payload data to new packet.
|
|
memcpy(new_packet.AllocatePayload(payload_size()), payload().data(),
|
|
payload_size());
|
|
|
|
// Allocate padding -- must be last!
|
|
new_packet.SetPadding(padding_size());
|
|
|
|
// Success, replace current packet with newly built packet.
|
|
*this = new_packet;
|
|
return true;
|
|
}
|
|
|
|
std::string RtpPacket::ToString() const {
|
|
rtc::StringBuilder result;
|
|
result << "{payload_type=" << payload_type_ << "marker=" << marker_
|
|
<< ", sequence_number=" << sequence_number_
|
|
<< ", padding_size=" << padding_size_ << ", timestamp=" << timestamp_
|
|
<< ", ssrc=" << ssrc_ << ", payload_offset=" << payload_offset_
|
|
<< ", payload_size=" << payload_size_ << ", total_size=" << size()
|
|
<< "}";
|
|
|
|
return result.Release();
|
|
}
|
|
|
|
} // namespace webrtc
|