kopia lustrzana https://github.com/f4exb/sdrangel
141 wiersze
4.2 KiB
C++
141 wiersze
4.2 KiB
C++
/*
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This file is a part of JRTPLIB
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Copyright (c) 1999-2017 Jori Liesenborgs
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Contact: jori.liesenborgs@gmail.com
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This library was developed at the Expertise Centre for Digital Media
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(http://www.edm.uhasselt.be), a research center of the Hasselt University
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(http://www.uhasselt.be). The library is based upon work done for
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my thesis at the School for Knowledge Technology (Belgium/The Netherlands).
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included
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in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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IN THE SOFTWARE.
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*/
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#include "rtcpsdespacket.h"
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namespace qrtplib
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{
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RTCPSDESPacket::RTCPSDESPacket(uint8_t *data, std::size_t datalength) :
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RTCPPacket(SDES, data, datalength)
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{
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knownformat = false;
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currentchunk = 0;
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itemoffset = 0;
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curchunknum = 0;
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RTCPCommonHeader *hdr = (RTCPCommonHeader *) data;
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std::size_t len = datalength;
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if (hdr->padding)
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{
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uint8_t padcount = data[datalength - 1];
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if ((padcount & 0x03) != 0) // not a multiple of four! (see rfc 3550 p 37)
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return;
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if (((std::size_t) padcount) >= len)
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return;
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len -= (std::size_t) padcount;
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}
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if (hdr->count == 0)
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{
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if (len != sizeof(RTCPCommonHeader))
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return;
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}
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else
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{
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int ssrccount = (int) (hdr->count);
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uint8_t *chunk;
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int chunkoffset;
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if (len < sizeof(RTCPCommonHeader))
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return;
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len -= sizeof(RTCPCommonHeader);
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chunk = data + sizeof(RTCPCommonHeader);
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while ((ssrccount > 0) && (len > 0))
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{
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if (len < (sizeof(uint32_t) * 2)) // chunk must contain at least a SSRC identifier
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return; // and a (possibly empty) item
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len -= sizeof(uint32_t);
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chunkoffset = sizeof(uint32_t);
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bool done = false;
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while (!done)
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{
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if (len < 1) // at least a zero byte (end of item list) should be there
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return;
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RTCPSDESHeader *sdeshdr = (RTCPSDESHeader *) (chunk + chunkoffset);
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if (sdeshdr->sdesid == 0) // end of item list
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{
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len--;
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chunkoffset++;
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std::size_t r = (chunkoffset & 0x03);
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if (r != 0)
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{
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std::size_t addoffset = 4 - r;
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if (addoffset > len)
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return;
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len -= addoffset;
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chunkoffset += addoffset;
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}
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done = true;
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}
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else
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{
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if (len < sizeof(RTCPSDESHeader))
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return;
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len -= sizeof(RTCPSDESHeader);
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chunkoffset += sizeof(RTCPSDESHeader);
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std::size_t itemlen = (std::size_t)(sdeshdr->length);
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if (itemlen > len)
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return;
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len -= itemlen;
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chunkoffset += itemlen;
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}
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}
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ssrccount--;
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chunk += chunkoffset;
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}
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// check for remaining bytes
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if (len > 0)
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return;
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if (ssrccount > 0)
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return;
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}
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knownformat = true;
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}
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} // end namespace
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