sdp.cxx

一个SIP协议栈

// $Id: sdp.cxx,v 1.3 1999/08/31 01:53:27 cullen Exp $

/*

This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not; write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.

*/

// $Log: sdp.cxx,v $
// Revision 1.3  1999/08/31 01:53:27  cullen
// Cullen check in some code from Luan that has things needed to compile
//
// Revision 1.8  1999/07/23 23:57:25  bogawa
//
// the mgcp/examples/gateway Makefile was changed to use the new make file system.
//
// improve the global makefiles.  Now, most targets use these makefiles
// which should simplify the lives of the users, we hope.
//
// Key features include support for nested object directories as well as
// a more coherent install strategy (so that installs are less likely to
// produce error messages)
//
// in addition, the code was cleaned up to add a few new features and to
// remove some warnings.
//
// Revision 1.7  1999/07/12 23:35:33  bogawa
//
// fix for the sdp.
//
// Revision 1.6  1999/06/30 06:09:08  bogawa
//
// update copyright and license
//
// Revision 1.5  1999/06/29 23:42:03  bogawa
//
// Updated copyright notice.
//
// Revision 1.4  1999/06/28 21:30:37  bogawa
//
// Update to the latest version of the MGCP stack.
//
// Revision 1.3  1999/06/09 08:16:44  bogawa
//
// Add copyright notices.
//
// Revision 1.2  1999/06/09 01:04:59  bogawa
//
// Changes to make the new structure compile correctly, and to allow the
// code to use the new hardware structure.  gateway1 is now using the
// new structure fully, while gateway2 is using it partially (actually
// not very much).
//
// A future version should be much cleaner.
//

// implement simple session description protocol

#include <assert.h>
#include "sdp.hxx"
#include "mstring.h"
#include <strstream>


std::mstring* SDPDescriptor::encode()
{
    ostrstream s(buf, 1024);

    buf[0] = '\0';

    // encode the puppy
    s << "v=" << protocolVersion << "\r\n";

    s << "o=" << username << " " << sessionId << " " << version << " ";
    if(networkType == NetworkTypeInternet)
    {
	s << "IN ";
    }
    else
    {
	s << "unknown ";
    }

    if(addressType == AddressTypeIPV4)
    {
	s << "IP4 ";
    }
    else
    {
	s << "unknown ";
    }

    s << address << "\r\n";


    s << "s=" << sessionName << "\r\n";


    s << "c=";

    if(networkType == NetworkTypeInternet)
    {
	s << "IN ";
    }
    else
    {
	s << "unknown ";
    }
    
    if(addressType == AddressTypeIPV4)
    {
	s << "IP4 ";
    }
    else
    {
	s << "unknown ";
    }

    s << address << "\r\n";


    s << "m=" ;

    if(mediaType == MediaTypeAudio)
    {
	s << "audio ";
    }

    s << port << " ";

    if(transportType == TransportTypeRTP)
    {
	s << "RTP/AVP";
    }

    std::vector <int>::iterator iter;
    iter = formatList.begin();

    assert (iter != formatList.end());

    while(iter != formatList.end())
    {
	s << " " << static_cast<int>(*iter);
	++iter;
    }

    s << "\r\n" << '\0';
    myEncoding = s.str();

    return &myEncoding;
}

bool SDPDescriptor::decode(const std::mstring& buffer)
{
    std::vector<std::mstring> lines;

    buffer.split(&lines, "\n", "", 0, std::mstring::sep_single);

    return decode(lines);
}

bool SDPDescriptor::decode(const std::vector<std::mstring>& parms)
{
    std::vector<std::mstring> lines(parms);

    return decode(lines);
}


bool SDPDescriptor::decode(std::vector<std::mstring>& lines)
{

    if(lines.size() <= 3)
    {
	// no good --

	return false;

    }

    std::vector<std::mstring>::iterator linecount;

    linecount = lines.begin();

    {
	// lines[0] is the version line -- ignore

        linecount->rtrimc('\r');

	if(*linecount != "v=0")
	{
	    // no good
	    return false;
	}

	++linecount;

        linecount->rtrimc('\r');

	if(((*linecount).find("o=")) != 0)
	{
	    // match on this line is BAD
	    return false;
	}

	// parse line 1 for the proper stuff

	(*linecount).erase(0, 2);

	std::vector<std::mstring> optionsList;

	linecount->split(&optionsList, " ", "");

	if(optionsList.size() < 6)
	{
	    // not enough parameters
	    return false;
	}

	username = optionsList[0];
	sessionId = atoi(optionsList[1].c_str());
	version = atoi(optionsList[2].c_str());
	if(optionsList[3] == "IN")
	{
	    networkType = NetworkTypeInternet;
	}
	else
	{
	    // bad!
	    return false;
	}

	if(optionsList[4] == "IP4")
	{
	    addressType = AddressTypeIPV4;
	}
	else
	{
	    return false;
	}

	address = optionsList[5].c_str();

	// parse the session name

	++linecount;

        linecount->rtrimc('\r');

	if(((*linecount).find("s=")) != 0)
	{
	    return false;
	}

	sessionName = (*linecount).substr(2, (*linecount).length() - 2);

	++linecount;

	while((linecount != lines.end()) && ((*linecount).find("m=") != 0))
	{
            linecount->rtrimc('\r');

	    // pre media-channel items
	    if((*linecount).find("c=") == 0)
	    {
		// this is a c= line
		std::vector<std::mstring> cList;

		linecount->split(&cList, " ", "");

		// actually we'll ignore this... ?


	    }
	    ++linecount;
	}
	    
	// media channel items
	while(linecount != lines.end())
	{
            linecount->rtrimc('\r');

	    if((*linecount).find("m=") == 0)
	    {
		// this is a m= line

		std::vector<std::mstring> mList;

		linecount->split(&mList, " ", "");

		if(mList.size() < 4)
		{
		    assert(0);
		    return false;
		}
		std::vector<std::mstring>::iterator mListIter;

		mListIter = mList.begin();

		if(*mListIter == "audio")
		{
		    mediaType = MediaTypeAudio;
		}
		++mListIter;
		// xxx needs splitting help

		port = atoi((*mListIter).c_str());

		++mListIter;

		if(*mListIter == "RTP/AVP")
		{
		    transportType = TransportTypeRTP;
		}
		else if(*mListIter == "UDP")
		{
		    transportType = TransportTypeUDP;
		}

		++mListIter;

		formatList.clear();
		while(mListIter != mList.end())
		{
		    // these are all format list items
		    formatList.push_back(atoi((*mListIter).c_str()));

		    ++mListIter;
		}
		assert(formatList.size() != 0);
	    }
	    ++linecount;
	}


    }
    isValid = true;
    return true;
}
;