sdp.cxx

sloedgy open sip stack source code

/*
 * sdp.cxx
 *
 * Session Description Protocol support.
 *
 * Open Phone Abstraction Library (OPAL)
 *
 * Copyright (c) 2000 Equivalence Pty. Ltd.
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Open Phone Abstraction Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Contributor(s): ______________________________________.
 *
 * $Log: sdp.cxx,v $
 * Revision 1.3  2006/12/02 01:12:44  joegenbaclor
 * Initial upload of SoftPhoneInterface classes
 *
 * Revision 1.2  2006/08/03 12:48:06  joegenbaclor
 * Minor tweaks for integrating pwlib into OSS source tree
 *
 * Revision 1.1  2006/06/26 03:03:54  joegenbaclor
 * I have decided to include the latest development realease  of OPAL tagged Deimos Devel 1 (June 8 2006) as inegrated classes to opensipstack to avoid future version conflicts due to the fast pace in OPAL development.   This move is also aimed to reduce the size of projects using OPAL componets such as the soon to be relased OpenSIPPhone.
 *
 * Revision 2.36  2006/04/30 09:58:44  csoutheren
 * Added IPV6 handlng to SDP
 *
 * Revision 2.35  2006/04/23 20:12:52  dsandras
 * The RFC tells that the SDP answer SHOULD have the same payload type than the
 * SDP offer. Added rtpmap support to allow this. Fixes problems with Asterisk,
 * and Ekiga report #337456.
 *
 * Revision 2.34  2006/04/22 09:32:18  dsandras
 * Fixed compilation error with GCC on Linux.
 *
 * Revision 2.33  2006/04/21 14:36:51  hfriederich
 * Adding ability to parse and transmit simple bandwidth information
 *
 * Revision 2.32  2006/03/29 23:53:54  csoutheren
 * Make sure OpalTransportAddresses that are parsed from SDP are always udp$ and not
 *  tcp$
 *
 * Revision 2.31  2006/03/20 00:41:43  csoutheren
 * Fixed typo in last submit
 *
 * Revision 2.30  2006/03/20 00:20:15  csoutheren
 * Fixed problem with output empty image media formats
 *
 * Revision 2.29  2006/03/08 10:59:03  csoutheren
 * Applied patch #1444783 - Add 'image' SDP meda type and 'udptl' transport protocol
 * Thanks to Drazen Dimoti
 *
 * Revision 2.28  2006/02/08 04:51:58  csoutheren
 * Don't output media description when no formats to output
 *
 * Revision 2.27  2006/02/02 07:02:58  csoutheren
 * Added RTP payload map to transcoders and connections to allow remote SIP endpoints
 * to change the payload type used for outgoing RTP.
 *
 * Revision 2.26  2006/01/02 11:28:07  dsandras
 * Some documentation. Various code cleanups to prevent duplicate code.
 *
 * Revision 2.25  2005/12/29 16:23:38  dsandras
 * Media formats with different clock rates are not identical.
 *
 * Revision 2.24  2005/12/27 20:51:20  dsandras
 * Added clockRate parameter support.
 *
 * Revision 2.23  2005/10/04 18:31:01  dsandras
 * Allow SetFMTP and GetFMTP to work with any option set for a=fmtp:.
 *
 * Revision 2.22  2005/09/15 17:01:08  dsandras
 * Added support for the direction attributes in the audio & video media descriptions and in the session.
 *
 * Revision 2.21  2005/08/25 18:50:55  dsandras
 * Added support for clockrate based on the media format.
 *
 * Revision 2.20  2005/07/18 01:19:37  csoutheren
 * Fixed proxy with FWD rejecting call because of the order of the SDP fields
 * I can't see any requirement for ordering in the RFC, so this is probably a
 * bug in the FWD proxy
 *
 * Revision 2.19  2005/07/14 08:52:19  csoutheren
 * Modified to output media desscription specific connection address if needed
 *
 * Revision 2.18  2005/04/28 20:22:54  dsandras
 * Applied big sanity patch for SIP thanks to Ted Szoczei <[e-mail]>.
 * Thanks a lot!
 *
 * Revision 2.17  2005/04/10 21:19:38  dsandras
 * Added support to set / get the stream direction in a SDP.
 *
 * Revision 2.16  2004/10/24 10:45:19  rjongbloed
 * Back out change of strcasecmp to strcmp for WinCE
 *
 * Revision 2.15  2004/10/23 11:43:05  ykiryanov
 * Added ifdef _WIN32_WCE for PocketPC 2003 SDK port
 *
 * Revision 2.14  2004/04/27 07:22:40  rjongbloed
 * Adjusted some logging
 *
 * Revision 2.13  2004/03/25 11:51:12  rjongbloed
 * Changed PCM-16 from IllegalPayloadType to MaxPayloadType to avoid problems
 *   in other parts of the code.
 * Changed to hame m= line for every codec, including "known" ones, thanks Ted Szoczei
 *
 * Revision 2.12  2004/03/22 11:32:42  rjongbloed
 * Added new codec type for 16 bit Linear PCM as must distinguish between the internal
 *   format used by such things as the sound card and the RTP payload format which
 *   is always big endian.
 *
 * Revision 2.11  2004/02/09 13:13:02  rjongbloed
 * Added debug string output for media type enum.
 *
 * Revision 2.10  2004/02/07 02:18:19  rjongbloed
 * Improved searching for media format to use payload type AND the encoding name.
 *
 * Revision 2.9  2004/01/08 22:23:23  csoutheren
 * Fixed problem with not using session ID when constructing SDP lists
 *
 * Revision 2.8  2004/01/08 22:20:43  csoutheren
 * Fixed problem with not using session ID when constructing SDP lists
 *
 * Revision 2.7  2003/12/15 11:56:17  rjongbloed
 * Applied numerous bug fixes, thank you very much Ted Szoczei
 *
 * Revision 2.6  2003/03/17 22:31:35  robertj
 * Fixed warnings
 *
 * Revision 2.5  2002/06/16 02:22:49  robertj
 * Fixed memory leak of RFC2833 ordinals, thanks Ted Szoczei
 *
 * Revision 2.4  2002/02/19 07:51:37  robertj
 * Added OpalRFC2833 as a OpalMediaFormat variable.
 * Fixed encoding name being used correctly in SDP media list.
 *
 * Revision 2.3  2002/02/13 02:28:59  robertj
 * Normalised some function names.
 * Fixed incorrect port number usage stopping audio in one direction.
 * Added code to put individual c lines in each media description.
 *
 * Revision 2.2  2002/02/11 07:35:35  robertj
 * Changed SDP to use OpalTransport for hosts instead of IP addresses/ports
 *
 * Revision 2.1  2002/02/01 04:53:01  robertj
 * Added (very primitive!) SIP support.
 *
 */

#include <ptlib.h>

#ifdef __GNUC__
#pragma implementation "sdp.h"
#endif

#include <opal/sdp.h>

#include <ptlib/socket.h>
#include <opal/transports.h>


#define SIP_DEFAULT_SESSION_NAME  "OSS RTP Session"
#define	SDP_MEDIA_TRANSPORT       "RTP/AVP"
#define	SDP_MEDIA_TRANSPORT_UDPTL "udptl"

#define new PNEW


/////////////////////////////////////////////////////////

static OpalTransportAddress ParseConnectAddress(const PStringArray & tokens, PINDEX offset)
{
  if (tokens.GetSize() == offset+3) {
    if (tokens[offset] *= "IN") {
      if ((tokens[offset+1] *= "IP4") 
#if P_HAS_IPV6
        || (tokens[offset+1] *= "IP6")
#endif
        )
        return OpalTransportAddress(tokens[offset+2], 0, "udp");
      else {
        PTRACE(1, "SDP\tConnect address has invalid address type \"" << tokens[offset+1] << '"');
      }
    }
    else {
      PTRACE(1, "SDP\tConnect address has invalid network \"" << tokens[offset] << '"');
    }
  }
  else {
    PTRACE(1, "SDP\tConnect address has invalid (" << tokens.GetSize() << ") elements");
  }

  return OpalTransportAddress();
}


static OpalTransportAddress ParseConnectAddress(const PString & str)
{
  PStringArray tokens = str.Tokenise(' ');
  return ParseConnectAddress(tokens, 0);
}


static PString GetConnectAddressString(const OpalTransportAddress & address)
{
  PStringStream str;

  PIPSocket::Address ip;
  if (address != 0 && address.GetIpAddress(ip))
    str << "IN IP" << ip.GetVersion() << ' ' << ip;
  else
    str << "IN IP4 0.0.0.0";

  return str;
}


/////////////////////////////////////////////////////////

SDPMediaFormat::SDPMediaFormat(RTP_DataFrame::PayloadTypes pt,
                               const char * _name,
                               unsigned _clockRate,
                               const char * _parms)
  : payloadType(pt),
    clockRate(_clockRate),
    encodingName(_name),
    parameters(_parms),
    nteSet(TRUE)
{
  if (encodingName == OpalRFC2833.GetEncodingName())
    AddNTEString("0-15");
}


SDPMediaFormat::SDPMediaFormat(const PString & nteString, RTP_DataFrame::PayloadTypes pt)

  : payloadType(pt),
    clockRate(8000),
    encodingName(OpalRFC2833.GetEncodingName()),
    nteSet(TRUE)
{
  AddNTEString(nteString);
}


void SDPMediaFormat::SetFMTP(const PString & str)
{
  if (encodingName == OpalRFC2833.GetEncodingName()) {
    nteSet.RemoveAll();
    AddNTEString(str);
  }
  else {
    fmtp = str;
  }
}


PString SDPMediaFormat::GetFMTP() const
{
  if (encodingName == OpalRFC2833.GetEncodingName())
    return GetNTEString();
  else
    return fmtp;
}


PString SDPMediaFormat::GetNTEString() const
{
  POrdinalSet & nteSetNc = (POrdinalSet &)nteSet;
  PString str;
  PINDEX i = 0;
  while (i < nteSet.GetSize()) {
    if (!nteSetNc.Contains(POrdinalKey(i)))
      i++;
    else {
      PINDEX start = i++;
      while (nteSetNc.Contains(POrdinalKey(i)))
        i++;
      if (!str.IsEmpty())
        str += ",";
      str += PString(PString::Unsigned, start);
      if (i > start+1)
        str += PString('-') + PString(PString::Unsigned, i-1);
    }
  }

  return str;
}


void SDPMediaFormat::AddNTEString(const PString & str)
{
  PStringArray tokens = str.Tokenise(",", FALSE);
  PINDEX i;
  for (i = 0; i < tokens.GetSize(); i++)
    AddNTEToken(tokens[i]);
}


void SDPMediaFormat::AddNTEToken(const PString & ostr)
{
  PString str = ostr.Trim();
  if (str[0] == ',')
    str = str.Mid(1);
  if (str.Right(1) == ",")
    str = str.Left(str.GetLength()-1);
  PINDEX pos = str.Find('-');
  if (pos == P_MAX_INDEX)
    nteSet.Include(new POrdinalKey(str.AsInteger()));
  else {
    PINDEX from = str.Left(pos).AsInteger();
    PINDEX to   = str.Mid(pos+1).AsInteger();
    while (from <= to)
      nteSet.Include(new POrdinalKey(from++));
  }
}


void SDPMediaFormat::PrintOn(ostream & strm) const
{
  PAssert(!encodingName.IsEmpty(), "SDPAudioMediaFormat encoding name is empty");

  strm << "a=rtpmap:" << (int)payloadType << ' ' << encodingName << '/' << clockRate;
  if (!parameters.IsEmpty())
    strm << '/' << parameters;
  strm << "\r\n";

  PString fmtpString = GetFMTP();

  if (!fmtpString.IsEmpty())
    strm << "a=fmtp:" << (int)payloadType << ' ' << fmtpString << "\r\n";
}


OpalMediaFormat SDPMediaFormat::GetMediaFormat() const
{
  return OpalMediaFormat(payloadType, clockRate, encodingName);
}


//////////////////////////////////////////////////////////////////////////////

#if PTRACING
ostream & operator<<(ostream & out, SDPMediaDescription::MediaType type)
{
  static const char * const MediaTypeNames[SDPMediaDescription::NumMediaTypes] = {
    "Audio", "Video", "Application", "Image", "Unknown"
  };

  if (type < PARRAYSIZE(MediaTypeNames) && MediaTypeNames[type] != NULL)
    out << MediaTypeNames[type];
  else
    out << "MediaTypes<" << (int)type << '>';

  return out;
}
#endif

SDPMediaDescription::SDPMediaDescription(const OpalTransportAddress & address, MediaType _mediaType)
  : mediaType(_mediaType),
    transportAddress(address),
	packetTime(0)
{
  switch (mediaType) {
    case Audio:
      media = "audio";
      break;
    case Video:
      media = "video";
      break;
    case Image:
      media = "image";
      break;
    default:
      break;
  }

  transport = (mediaType == Image) ? SDP_MEDIA_TRANSPORT_UDPTL : SDP_MEDIA_TRANSPORT;
  direction = Undefined;
}


BOOL SDPMediaDescription::Decode(const PString & str)
{
  PStringArray tokens = str.Tokenise(" ");

  if (tokens.GetSize() < 4) {
    PTRACE(1, "SDP\tMedia session has only " << tokens.GetSize() << " elements");
    return FALSE;
  }

  media = tokens[0];
  if (media == "video")
    mediaType = Video;
  else if (media == "audio")
    mediaType = Audio;
  else if (media == "image")
    mediaType = Image;
  else {
    PTRACE(1, "SDP\tUnknown media type " << media);
    mediaType = Unknown;
  }

  PString portStr  = tokens[1];
  transport        = tokens[2];

  // parse the port and port count
  PINDEX pos = portStr.Find('/');
  if (pos == P_MAX_INDEX) 
    portCount = 1;
  else {
    PTRACE(1, "SDP\tMedia header contains port count - " << portStr);
    portCount = (WORD)portStr.Mid(pos+1).AsUnsigned();
    portStr   = portStr.Left(pos);
  }
  unsigned port = portStr.AsUnsigned();
  PTRACE(4, "SDP\tMedia session port=" << port);

  if ((transport != SDP_MEDIA_TRANSPORT) && (transport != SDP_MEDIA_TRANSPORT_UDPTL)) {
    PTRACE(1, "SDP\tMedia session has only " << tokens.GetSize() << " elements");
    return FALSE;
  }

  PIPSocket::Address ip;
  transportAddress.GetIpAddress(ip);
  transportAddress = OpalTransportAddress(ip, (WORD)port);

  // create the format list
  PINDEX i;
  for (i = 3; i < tokens.GetSize(); i++) {
    if (mediaType == Image)
      formats.Append(new SDPMediaFormat((RTP_DataFrame::PayloadTypes)RTP_DataFrame::DynamicBase, tokens[i], 0));
    else
      formats.Append(new SDPMediaFormat((RTP_DataFrame::PayloadTypes)tokens[i].AsUnsigned()));
  }

  return TRUE;
}


void SDPMediaDescription::SetAttribute(const PString & ostr)
{
  // get the attribute type
  PINDEX pos = ostr.Find(":");
  if (pos == P_MAX_INDEX) {

    if (ostr *= "sendonly")
      direction = SendOnly;
    else if (ostr *= "recvonly")
      direction = RecvOnly;
    else if (ostr *= "sendrecv")
      direction = SendRecv;
    else if (ostr *= "inactive")
      direction = Inactive;
    else
      PTRACE(2, "SDP\tMalformed media attribute " << ostr);
    return;
  }
  PString attr = ostr.Left(pos);
  PString str  = ostr.Mid(pos+1);

  if (attr *= "ptime") {                // caseless comparison
      packetTime = str.AsUnsigned() ;
      return;
  }

  // extract the RTP payload type
  pos = str.Find(" ");
  if (pos == P_MAX_INDEX) {
    PTRACE(2, "SDP\tMalformed media attribute " << ostr);
    return;
  }