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/*
* 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/common_header.h"
#include <cstddef>
#include <cstdint>
#include "modules/rtp_rtcp/source/byte_io.h"
#include "rtc_base/logging.h"
namespace webrtc {
namespace rtcp {
// 0 1 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// 0 |V=2|P| C/F |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// 1 | Packet Type |
// ----------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// 2 | length |
// --------------------------------+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//
// Common header for all RTCP packets, 4 octets.
bool CommonHeader::Parse(const uint8_t* buffer, size_t size_bytes) {
const uint8_t kVersion = 2;
if (size_bytes < kHeaderSizeBytes) {
RTC_LOG(LS_WARNING)
<< "Too little data (" << size_bytes << " byte"
<< (size_bytes != 1 ? "s" : "")
<< ") remaining in buffer to parse RTCP header (4 bytes).";
return false;
}
uint8_t version = buffer[0] >> 6;
if (version != kVersion) {
RTC_LOG(LS_WARNING) << "Invalid RTCP header: Version must be "
<< static_cast<int>(kVersion) << " but was "
<< static_cast<int>(version);
return false;
}
bool has_padding = (buffer[0] & 0x20) != 0;
count_or_format_ = buffer[0] & 0x1F;
packet_type_ = buffer[1];
payload_size_ = ByteReader<uint16_t>::ReadBigEndian(&buffer[2]) * 4;
payload_ = buffer + kHeaderSizeBytes;
padding_size_ = 0;
if (size_bytes < kHeaderSizeBytes + payload_size_) {
RTC_LOG(LS_WARNING) << "Buffer too small (" << size_bytes
<< " bytes) to fit an RtcpPacket with a header and "
<< payload_size_ << " bytes.";
return false;
}
if (has_padding) {
if (payload_size_ == 0) {
RTC_LOG(LS_WARNING)
<< "Invalid RTCP header: Padding bit set but 0 payload "
"size specified.";
return false;
}
padding_size_ = payload_[payload_size_ - 1];
if (padding_size_ == 0) {
RTC_LOG(LS_WARNING)
<< "Invalid RTCP header: Padding bit set but 0 padding "
"size specified.";
return false;
}
if (padding_size_ > payload_size_) {
RTC_LOG(LS_WARNING) << "Invalid RTCP header: Too many padding bytes ("
<< padding_size_ << ") for a packet payload size of "
<< payload_size_ << " bytes.";
return false;
}
payload_size_ -= padding_size_;
}
return true;
}
} // namespace rtcp
} // namespace webrtc
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