151 lines
4.9 KiB
C++
151 lines
4.9 KiB
C++
/*
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*
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* @APPLE_LICENSE_HEADER_START@
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*
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* Copyright (c) 1999-2008 Apple Inc. All Rights Reserved.
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*
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* This file contains Original Code and/or Modifications of Original Code
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* as defined in and that are subject to the Apple Public Source License
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* Version 2.0 (the 'License'). You may not use this file except in
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* compliance with the License. Please obtain a copy of the License at
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* http://www.opensource.apple.com/apsl/ and read it before using this
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* file.
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*
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* The Original Code and all software distributed under the License are
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* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
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* Please see the License for the specific language governing rights and
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* limitations under the License.
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*
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* @APPLE_LICENSE_HEADER_END@
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*
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*/
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/*
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File: RTCPAckPacket.h
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Contains: RTCPAckPacket de-packetizing class
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*/
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#ifndef _RTCPACKPACKET_H_
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#define _RTCPACKPACKET_H_
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#include "OSHeaders.h"
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#include "RTCPAPPPacket.h"
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#include <stdlib.h>
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#include "SafeStdLib.h"
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#ifndef __Win32__
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#include <netinet/in.h>
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#endif
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class RTCPAckPacket : public RTCPAPPPacket
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{
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public:
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/*
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RTCP app ACK packet
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# bytes description
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------- -----------
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4 rtcp header
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4 SSRC of receiver
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4 app type ('qtak')
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2 reserved (set to 0)
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2 seqNum
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*/
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//
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// This class is not derived from RTCPPacket as a performance optimization.
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// Instead, it is assumed that the RTCP packet validation has already been
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// done.
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RTCPAckPacket() : fRTCPAckBuffer(NULL), fAckMaskSize(0) {}
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virtual ~RTCPAckPacket() {}
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// Call to parse if you don't know what kind of packet this is
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// Returns true if this is an Ack packet, false otherwise.
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// Assumes that inPacketBuffer is a pointer to a valid RTCP packet header.
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Bool16 ParseAckPacket(UInt8* inPacketBuffer, UInt32 inPacketLength);
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virtual Bool16 ParseAPPData(UInt8* inPacketBuffer, UInt32 inPacketLength);
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inline UInt16 GetAckSeqNum();
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inline UInt32 GetAckMaskSizeInBits() { return fAckMaskSize * 8; }
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inline Bool16 IsNthBitEnabled(UInt32 inBitNumber);
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inline UInt16 GetPacketLength();
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void Dump();
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static void GetTestPacket(StrPtrLen* resultPtr) {} //todo
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enum
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{
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kAckPacketName = FOUR_CHARS_TO_INT('q', 't', 'a', 'k'), // 'qtak' documented Apple reliable UDP packet type
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kAckPacketAlternateName = FOUR_CHARS_TO_INT('a', 'c', 'k', ' '), // 'ack ' required by QT 5 and earlier
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};
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private:
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UInt8* fRTCPAckBuffer;
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UInt32 fAckMaskSize;
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Bool16 IsAckPacketType();
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enum
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{
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kAppPacketTypeOffset = 8,
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kAckSeqNumOffset = 16,
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kAckMaskOffset = 20,
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kPacketLengthMask = 0x0000FFFFUL,
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};
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inline Bool16 IsAckType(UInt32 theAppType) { return ( (theAppType == kAckPacketAlternateName) || (theAppType == kAckPacketName) );}
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};
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Bool16 RTCPAckPacket::IsNthBitEnabled(UInt32 inBitNumber)
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{
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// Don't need to do endian conversion because we're dealing with 8-bit numbers
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UInt8 bitMask = 128;
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return *(fRTCPAckBuffer + kAckMaskOffset + (inBitNumber >> 3)) & (bitMask >>= inBitNumber & 7);
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}
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UInt16 RTCPAckPacket::GetAckSeqNum()
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{
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return (UInt16) (ntohl(*(UInt32*)&fRTCPAckBuffer[kAckSeqNumOffset]));
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}
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inline UInt16 RTCPAckPacket::GetPacketLength()
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{
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return (UInt16) ( ntohl(*(UInt32*)fRTCPAckBuffer) & kPacketLengthMask);
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}
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/*
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6.6 Ack Packet format
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0 1 2 3
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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
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|V=2|P| subtype | PT=APP=204 | length |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| SSRC/CSRC |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| name (ASCII) = 'qtak' |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| SSRC/CSRC |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Reserved | Seq num |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Mask... |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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#endif //_RTCPAPPPACKET_H_
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