mirror of
				https://github.com/f4exb/sdrangel.git
				synced 2025-10-30 04:20:21 -04:00 
			
		
		
		
	
		
			
				
	
	
		
			141 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
| 
 | |
|  This file is a part of JRTPLIB
 | |
|  Copyright (c) 1999-2017 Jori Liesenborgs
 | |
| 
 | |
|  Contact: jori.liesenborgs@gmail.com
 | |
| 
 | |
|  This library was developed at the Expertise Centre for Digital Media
 | |
|  (http://www.edm.uhasselt.be), a research center of the Hasselt University
 | |
|  (http://www.uhasselt.be). The library is based upon work done for
 | |
|  my thesis at the School for Knowledge Technology (Belgium/The Netherlands).
 | |
| 
 | |
|  Permission is hereby granted, free of charge, to any person obtaining a
 | |
|  copy of this software and associated documentation files (the "Software"),
 | |
|  to deal in the Software without restriction, including without limitation
 | |
|  the rights to use, copy, modify, merge, publish, distribute, sublicense,
 | |
|  and/or sell copies of the Software, and to permit persons to whom the
 | |
|  Software is furnished to do so, subject to the following conditions:
 | |
| 
 | |
|  The above copyright notice and this permission notice shall be included
 | |
|  in all copies or substantial portions of the Software.
 | |
| 
 | |
|  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 | |
|  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 | |
|  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 | |
|  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 | |
|  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 | |
|  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 | |
|  IN THE SOFTWARE.
 | |
| 
 | |
|  */
 | |
| 
 | |
| #include "rtcpsdespacket.h"
 | |
| 
 | |
| namespace qrtplib
 | |
| {
 | |
| 
 | |
| RTCPSDESPacket::RTCPSDESPacket(uint8_t *data, std::size_t datalength) :
 | |
|         RTCPPacket(SDES, data, datalength)
 | |
| {
 | |
|     knownformat = false;
 | |
|     currentchunk = 0;
 | |
|     itemoffset = 0;
 | |
|     curchunknum = 0;
 | |
| 
 | |
|     RTCPCommonHeader *hdr = (RTCPCommonHeader *) data;
 | |
|     std::size_t len = datalength;
 | |
| 
 | |
|     if (hdr->padding)
 | |
|     {
 | |
|         uint8_t padcount = data[datalength - 1];
 | |
|         if ((padcount & 0x03) != 0) // not a multiple of four! (see rfc 3550 p 37)
 | |
|             return;
 | |
|         if (((std::size_t) padcount) >= len)
 | |
|             return;
 | |
|         len -= (std::size_t) padcount;
 | |
|     }
 | |
| 
 | |
|     if (hdr->count == 0)
 | |
|     {
 | |
|         if (len != sizeof(RTCPCommonHeader))
 | |
|             return;
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         int ssrccount = (int) (hdr->count);
 | |
|         uint8_t *chunk;
 | |
|         int chunkoffset;
 | |
| 
 | |
|         if (len < sizeof(RTCPCommonHeader))
 | |
|             return;
 | |
| 
 | |
|         len -= sizeof(RTCPCommonHeader);
 | |
|         chunk = data + sizeof(RTCPCommonHeader);
 | |
| 
 | |
|         while ((ssrccount > 0) && (len > 0))
 | |
|         {
 | |
|             if (len < (sizeof(uint32_t) * 2)) // chunk must contain at least a SSRC identifier
 | |
|                 return;                  // and a (possibly empty) item
 | |
| 
 | |
|             len -= sizeof(uint32_t);
 | |
|             chunkoffset = sizeof(uint32_t);
 | |
| 
 | |
|             bool done = false;
 | |
|             while (!done)
 | |
|             {
 | |
|                 if (len < 1) // at least a zero byte (end of item list) should be there
 | |
|                     return;
 | |
| 
 | |
|                 RTCPSDESHeader *sdeshdr = (RTCPSDESHeader *) (chunk + chunkoffset);
 | |
|                 if (sdeshdr->sdesid == 0) // end of item list
 | |
|                 {
 | |
|                     len--;
 | |
|                     chunkoffset++;
 | |
| 
 | |
|                     std::size_t r = (chunkoffset & 0x03);
 | |
|                     if (r != 0)
 | |
|                     {
 | |
|                         std::size_t addoffset = 4 - r;
 | |
| 
 | |
|                         if (addoffset > len)
 | |
|                             return;
 | |
|                         len -= addoffset;
 | |
|                         chunkoffset += addoffset;
 | |
|                     }
 | |
|                     done = true;
 | |
|                 }
 | |
|                 else
 | |
|                 {
 | |
|                     if (len < sizeof(RTCPSDESHeader))
 | |
|                         return;
 | |
| 
 | |
|                     len -= sizeof(RTCPSDESHeader);
 | |
|                     chunkoffset += sizeof(RTCPSDESHeader);
 | |
| 
 | |
|                     std::size_t itemlen = (std::size_t)(sdeshdr->length);
 | |
|                     if (itemlen > len)
 | |
|                         return;
 | |
| 
 | |
|                     len -= itemlen;
 | |
|                     chunkoffset += itemlen;
 | |
|                 }
 | |
|             }
 | |
| 
 | |
|             ssrccount--;
 | |
|             chunk += chunkoffset;
 | |
|         }
 | |
| 
 | |
|         // check for remaining bytes
 | |
|         if (len > 0)
 | |
|             return;
 | |
|         if (ssrccount > 0)
 | |
|             return;
 | |
|     }
 | |
| 
 | |
|     knownformat = true;
 | |
| }
 | |
| 
 | |
| } // end namespace
 | |
| 
 |