/*
  The oRTP library is an RTP (Realtime Transport Protocol - rfc3550) stack.
  Copyright (C) 2001  Simon MORLAT simon.morlat@linphone.org

  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 2.1 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
*/

#include "ortp/ortp.h"
#include "utils.h"
#include "ortp/rtpsession.h"
#include "rtpsession_priv.h"


#if defined(WIN32) || defined(_WIN32_WCE)
#include "ortp-config-win32.h"
#else
#include "ortp-config.h" /*needed for HAVE_SYS_UIO_H */
#endif

#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#define USE_SENDMSG 1
#endif

#define can_connect(s)	( (s)->use_connect && !(s)->symmetric_rtp)

static bool_t try_connect(int fd, const struct sockaddr *dest, socklen_t addrlen){
	if (connect(fd,dest,addrlen)<0){
		ortp_warning("Could not connect() socket: %s",getSocketError());
		return FALSE;
	}
	return TRUE;
}

static ortp_socket_t create_and_bind(const char *addr, int port, int *sock_family, bool_t reuse_addr){
	int err;
	int optval = 1;
	ortp_socket_t sock=-1;

#ifdef ORTP_INET6
	char num[8];
	struct addrinfo hints, *res0, *res;
#else
	struct sockaddr_in saddr;
#endif
	
#ifdef ORTP_INET6
	
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;
	snprintf(num, sizeof(num), "%d",port);
	err = getaddrinfo(addr,num, &hints, &res0);
	if (err!=0) {
		ortp_warning ("Error in getaddrinfo on (addr=%s port=%i): %s", addr, port, gai_strerror(err));
		return -1;
	}
	
	for (res = res0; res; res = res->ai_next) {
		sock = socket(res->ai_family, res->ai_socktype, 0);
		if (sock==-1)
			continue;

		if (reuse_addr){
			err = setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
					(SOCKET_OPTION_VALUE)&optval, sizeof (optval));
			if (err < 0)
			{
				ortp_warning ("Fail to set rtp address reusable: %s.", getSocketError());
			}
		}

		*sock_family=res->ai_family;
		err = bind (sock, res->ai_addr, res->ai_addrlen);
		if (err != 0){
			ortp_warning ("Fail to bind rtp socket to (addr=%s port=%i) : %s.", addr,port, getSocketError());
			close_socket (sock);
			sock=-1;
			continue;
		}
#ifndef __hpux
		switch (res->ai_family)
		  {
		    case AF_INET:
		      if (IN_MULTICAST(ntohl(((struct sockaddr_in *) res->ai_addr)->sin_addr.s_addr)))
			{
		          struct ip_mreq mreq;
			  mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *) res->ai_addr)->sin_addr.s_addr;
			  mreq.imr_interface.s_addr = INADDR_ANY;
			  err = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (SOCKET_OPTION_VALUE) &mreq, sizeof(mreq));
			  if (err < 0){
				ortp_warning ("Fail to join address group: %s.", getSocketError());
				close_socket (sock);
				sock=-1;
				continue;
			    }
			}
		      break;
		    case AF_INET6:
		      if (IN6_IS_ADDR_MULTICAST(&(((struct sockaddr_in6 *) res->ai_addr)->sin6_addr)))
			{
			  struct ipv6_mreq mreq;
			  mreq.ipv6mr_multiaddr = ((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
			  mreq.ipv6mr_interface = 0;
			  err = setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, (SOCKET_OPTION_VALUE)&mreq, sizeof(mreq));
			  if (err < 0)
			    {
			      ortp_warning ("Fail to join address group: %s.", getSocketError());
			      close_socket (sock);
			      sock=-1;
			      continue;
			    }
			}
		      break;
		  }
#endif /*hpux*/
		break;
	}
	freeaddrinfo(res0);
#else
	saddr.sin_family = AF_INET;
	*sock_family=AF_INET;
	err = inet_aton (addr, &saddr.sin_addr);
	if (err < 0)
	{
		ortp_warning ("Error in socket address:%s.", getSocketError());
		return -1;
	}
	saddr.sin_port = htons (port);

	sock = socket (PF_INET, SOCK_DGRAM, 0);
	if (sock==-1) return -1;

	if (reuse_addr){
		err = setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
				(SOCKET_OPTION_VALUE)&optval, sizeof (optval));
		if (err < 0)
		{
			ortp_warning ("Fail to set rtp address reusable: %s.",getSocketError());
		}
	}

	err = bind (sock,
		    (struct sockaddr *) &saddr,
		    sizeof (saddr));

	if (err != 0)
	{
		ortp_warning ("Fail to bind rtp socket to port %i: %s.", port, getSocketError());
		close_socket (sock);
		return -1;
	}
#endif
	if (sock!=-1){
		set_non_blocking_socket (sock);
	}
	return sock;
}

static void set_socket_sizes(int sock, unsigned int sndbufsz, unsigned int rcvbufsz){
	int err;
	bool_t done=FALSE;
	if (sndbufsz>0){
#ifdef SO_SNDBUFFORCE
		err = setsockopt(sock, SOL_SOCKET, SO_SNDBUFFORCE, (void *)&sndbufsz, sizeof(sndbufsz)); 
		if (err == -1) {
			ortp_error("Fail to increase socket's send buffer size with SO_SNDBUFFORCE: %s.", getSocketError());
		}else done=TRUE;
#endif
		if (!done){
			err = setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (void *)&sndbufsz, sizeof(sndbufsz)); 
			if (err == -1) {
				ortp_error("Fail to increase socket's send buffer size with SO_SNDBUF: %s.", getSocketError());
			}
		}
	}
	done=FALSE;
	if (rcvbufsz>0){
#ifdef SO_RCVBUFFORCE
		err = setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE, (void *)&rcvbufsz, sizeof(rcvbufsz)); 
		if (err == -1) {
			ortp_error("Fail to increase socket's recv buffer size with SO_RCVBUFFORCE: %s.", getSocketError());
		}
#endif
		if (!done){
			err = setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&rcvbufsz, sizeof(rcvbufsz)); 
			if (err == -1) {
				ortp_error("Fail to increase socket's recv buffer size with SO_RCVBUF: %s.", getSocketError());
			}
		}
		
	}
}

static ortp_socket_t create_and_bind_random(const char *localip, int *sock_family, int *port){
	int retry;
	ortp_socket_t sock = -1;
	for (retry=0;retry<100;retry++)
	{
		int localport;
		do
		{
			localport = (rand () + 5000) & 0xfffe;
		}
		while ((localport < 5000) || (localport > 0xffff));
		/*do not set REUSEADDR in case of random allocation */
		sock = create_and_bind(localip, localport, sock_family,FALSE);
		if (sock!=-1) {
			*port=localport;
			return sock;
		}
	}
	ortp_warning("create_and_bind_random: Could not find a random port for %s !",localip);
	return -1;
}

/**
 *rtp_session_set_local_addr:
 *@session:		a rtp session freshly created.
 *@addr:		a local IP address in the xxx.xxx.xxx.xxx form.
 *@port:		a local port or -1 to let oRTP choose the port randomly
 *
 *	Specify the local addr to be use to listen for rtp packets or to send rtp packet from.
 *	In case where the rtp session is send-only, then it is not required to call this function:
 *	when calling rtp_session_set_remote_addr(), if no local address has been set, then the 
 *	default INADRR_ANY (0.0.0.0) IP address with a random port will be used. Calling 
 *	rtp_sesession_set_local_addr() is mandatory when the session is recv-only or duplex.
 *
 *	Returns: 0 on success.
**/

int
rtp_session_set_local_addr (RtpSession * session, const char * addr, int port)
{
	ortp_socket_t sock;
	int sockfamily;
	if (session->rtp.socket>=0){
		/* don't rebind, but close before*/
		rtp_session_release_sockets(session);
	}
	/* try to bind the rtp port */
	if (port>0)
		sock=create_and_bind(addr,port,&sockfamily,TRUE);
	else
		sock=create_and_bind_random(addr,&sockfamily,&port);
	if (sock!=-1){
		set_socket_sizes(sock,session->rtp.snd_socket_size,session->rtp.rcv_socket_size);
		session->rtp.sockfamily=sockfamily;
		session->rtp.socket=sock;
		session->rtp.loc_port=port;
		/*try to bind rtcp port */
		sock=create_and_bind(addr,port+1,&sockfamily,TRUE);
		if (sock!=-1){
			session->rtcp.sockfamily=sockfamily;
			session->rtcp.socket=sock;
		}else{
			ortp_warning("Could not create and bind rtcp socket.");
		}
		
		/* set socket options (but don't change chosen states) */
		rtp_session_set_dscp( session, -1 );
		rtp_session_set_multicast_ttl( session, -1 );
		rtp_session_set_multicast_loopback( session, -1 );

		return 0;
	}
	return -1;
}


/**
 *rtp_session_set_multicast_ttl:
 *@session: a rtp session
 *@ttl: desired Multicast Time-To-Live
 *
 * Sets the TTL (Time-To-Live) for outgoing multicast packets.
 *
 * Returns: 0 on success.
 *
**/
int rtp_session_set_multicast_ttl(RtpSession *session, int ttl)
{
    int retval;
    
    // Store new TTL if one is specified
    if (ttl>0) session->multicast_ttl = ttl;
    
    // Don't do anything if socket hasn't been created yet
    if (session->rtp.socket < 0) return 0;

    switch (session->rtp.sockfamily) {
        case AF_INET: {
 
			retval= setsockopt(session->rtp.socket, IPPROTO_IP, IP_MULTICAST_TTL,
						 (SOCKET_OPTION_VALUE)  &session->multicast_ttl, sizeof(session->multicast_ttl));
            
			if (retval<0) break;

			retval= setsockopt(session->rtcp.socket, IPPROTO_IP, IP_MULTICAST_TTL,
					 (SOCKET_OPTION_VALUE)	   &session->multicast_ttl, sizeof(session->multicast_ttl));

 		} break;

        case AF_INET6: {

			retval= setsockopt(session->rtp.socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 
					 (SOCKET_OPTION_VALUE)&session->multicast_ttl, sizeof(session->multicast_ttl));
					
			if (retval<0) break;
			
			retval= setsockopt(session->rtcp.socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 
					 (SOCKET_OPTION_VALUE) &session->multicast_ttl, sizeof(session->multicast_ttl));

        } break;

        default:
            retval=-1;
    }
    
	if (retval<0)
		ortp_warning("Failed to set multicast TTL on socket.");
  

	return retval;
}


/**
 *rtp_session_get_multicast_ttl:
 *@session: a rtp session
 *
 * Returns the TTL (Time-To-Live) for outgoing multicast packets.
 *
**/
int rtp_session_get_multicast_ttl(RtpSession *session)
{
	return session->multicast_ttl;
}


/**
 *rtp_session_set_multicast_loopback:
 *@session: a rtp session
 *@ttl: desired Multicast Time-To-Live
 *
 * Sets the TTL (Time-To-Live) for outgoing multicast packets.
 *
 * Returns: 0 on success.
 *
**/
int rtp_session_set_multicast_loopback(RtpSession *session, int yesno)
{
    int retval;
    
    // Store new loopback state if one is specified
    if (yesno==0) {
    	// Don't loop back
    	session->multicast_loopback = 0;
    } else if (yesno>0) {
    	// Do loop back
    	session->multicast_loopback = 1;
    }
     
    // Don't do anything if socket hasn't been created yet
    if (session->rtp.socket < 0) return 0;

    switch (session->rtp.sockfamily) {
        case AF_INET: {
 
			retval= setsockopt(session->rtp.socket, IPPROTO_IP, IP_MULTICAST_LOOP,
						 (SOCKET_OPTION_VALUE)   &session->multicast_loopback, sizeof(session->multicast_loopback));
            
			if (retval<0) break;

			retval= setsockopt(session->rtcp.socket, IPPROTO_IP, IP_MULTICAST_LOOP,
						 (SOCKET_OPTION_VALUE)   &session->multicast_loopback, sizeof(session->multicast_loopback));

 		} break;

        case AF_INET6: {

			retval= setsockopt(session->rtp.socket, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, 
				 (SOCKET_OPTION_VALUE)	&session->multicast_loopback, sizeof(session->multicast_loopback));
					
			if (retval<0) break;
			
			retval= setsockopt(session->rtcp.socket, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, 
				 (SOCKET_OPTION_VALUE)	&session->multicast_loopback, sizeof(session->multicast_loopback));

        } break;

        default:
            retval=-1;
    }
    
	if (retval<0)
		ortp_warning("Failed to set multicast loopback on socket.");
  

	return retval;
}


/**
 *rtp_session_get_multicast_loopback:
 *@session: a rtp session
 *
 * Returns the multicast loopback state of rtp session (true or false).
 *
**/
int rtp_session_get_multicast_loopback(RtpSession *session)
{
	return session->multicast_loopback;
}

/**
 *rtp_session_set_dscp:
 *@session: a rtp session
 *@dscp: desired DSCP PHB value
 *
 * Sets the DSCP (Differentiated Services Code Point) for outgoing RTP packets.
 *
 * Returns: 0 on success.
 *
**/
int rtp_session_set_dscp(RtpSession *session, int dscp){
	int retval=0;
	int tos;

	// Store new DSCP value if one is specified
	if (dscp>=0) session->dscp = dscp;
	
	// Don't do anything if socket hasn't been created yet
	if (session->rtp.socket < 0) return 0;

	// DSCP value is in the upper six bits of the TOS field
	tos = (session->dscp << 2) & 0xFC;
	switch (session->rtp.sockfamily) {
		case AF_INET:
		retval = setsockopt(session->rtp.socket, IPPROTO_IP, IP_TOS, (SOCKET_OPTION_VALUE)&tos, sizeof(tos));
		break;
#ifdef ORTP_INET6
	case AF_INET6:
#	ifdef IPV6_TCLASS /*seems not defined by my libc*/
		retval = setsockopt(session->rtp.socket, IPPROTO_IPV6, IPV6_TCLASS,
		 (SOCKET_OPTION_VALUE)&tos, sizeof(tos));
#	else
		/*in case that works:*/
		retval = setsockopt(session->rtp.socket, IPPROTO_IPV6, IP_TOS,
		 (SOCKET_OPTION_VALUE)&tos, sizeof(tos));
#endif
		break;
#endif
	default:
		retval=-1;
	}
	if (retval<0)
		ortp_warning("Failed to set DSCP value on socket.");

	return retval;
}


/**
 *rtp_session_get_dscp:
 *@session: a rtp session
 *
 * Returns the DSCP (Differentiated Services Code Point) for outgoing RTP packets.
 *
**/
int rtp_session_get_dscp(const RtpSession *session)
{
	return session->dscp;
}


/**
 *rtp_session_get_local_port:
 *@session:	a rtp session for which rtp_session_set_local_addr() or rtp_session_set_remote_addr() has been called
 *
 *	This function can be useful to retrieve the local port that was randomly choosen by 
 *	rtp_session_set_remote_addr() when rtp_session_set_local_addr() was not called.
 *
 *	Returns: the local port used to listen for rtp packets, -1 if not set.
**/

int rtp_session_get_local_port(const RtpSession *session){
	return (session->rtp.loc_port>0) ? session->rtp.loc_port : -1;
}


static char * ortp_inet_ntoa(struct sockaddr *addr, int addrlen, char *dest, int destlen){
#ifdef ORTP_INET6
	int err;
	dest[0]=0;
	err=getnameinfo(addr,addrlen,dest,destlen,NULL,0,NI_NUMERICHOST);
	if (err!=0){
		ortp_warning("getnameinfo error: %s",gai_strerror(err));
	}
#else
	char *tmp=inet_ntoa(((struct sockaddr_in*)addr)->sin_addr);
	strncpy(dest,tmp,destlen);
	dest[destlen-1]='\0';
#endif
	return dest;
}

/**
 *rtp_session_set_remote_addr:
 *@session:		a rtp session freshly created.
 *@addr:		a local IP address in the xxx.xxx.xxx.xxx form.
 *@port:		a local port.
 *
 *	Sets the remote address of the rtp session, ie the destination address where rtp packet
 *	are sent. If the session is recv-only or duplex, it also sets the origin of incoming RTP 
 *	packets. Rtp packets that don't come from addr:port are discarded.
 *
 *	Returns: 0 on success.
**/
int
rtp_session_set_remote_addr (RtpSession * session, const char * addr, int port){
	return rtp_session_set_remote_addr_full (session, addr, port, port+1);
}

/**
 *rtp_session_set_remote_addr_full:
 *@session:		a rtp session freshly created.
 *@addr:		a local IP address in the xxx.xxx.xxx.xxx form.
 *@rtp_port:		a local rtp port.
 *@rtcp_port:		a local rtcp port.
 *
 *	Sets the remote address of the rtp session, ie the destination address where rtp packet
 *	are sent. If the session is recv-only or duplex, it also sets the origin of incoming RTP 
 *	packets. Rtp packets that don't come from addr:port are discarded.
 *
 *	Returns: 0 on success.
**/

int
rtp_session_set_remote_addr_full (RtpSession * session, const char * addr, int rtp_port, int rtcp_port)
{
	int err;
#ifdef ORTP_INET6
	struct addrinfo hints, *res0, *res;
	char num[8];
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;
	snprintf(num, sizeof(num), "%d", rtp_port);
	err = getaddrinfo(addr, num, &hints, &res0);
	if (err) {
		ortp_warning ("Error in socket address: %s", gai_strerror(err));
		return -1;
	}
#endif
	if (session->rtp.socket == -1){
		/* the session has not its socket bound, do it */
		ortp_message ("Setting random local addresses.");
#ifdef ORTP_INET6
		/* bind to an address type that matches the destination address */
		if (res0->ai_addr->sa_family==AF_INET6)
			err = rtp_session_set_local_addr (session, "::", -1);
		else err=rtp_session_set_local_addr (session, "0.0.0.0", -1);
#else
		err = rtp_session_set_local_addr (session, "0.0.0.0", -1);
#endif
		if (err<0) return -1;
	}

#ifdef ORTP_INET6
	err=1;
	for (res = res0; res; res = res->ai_next) {
		/* set a destination address that has the same type as the local address */
		if (res->ai_family==session->rtp.sockfamily ) {
			memcpy( &session->rtp.rem_addr, res->ai_addr, res->ai_addrlen);
			session->rtp.rem_addrlen=res->ai_addrlen;
		  	err=0;
		  	break;
		}
	}
	freeaddrinfo(res0);
	if (err) {
		ortp_warning("Could not set destination for RTP socket to %s:%i.",addr,rtp_port);
		return -1;
	}
	
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;
	snprintf(num, sizeof(num), "%d", rtcp_port);
	err = getaddrinfo(addr, num, &hints, &res0);
	if (err) {
		ortp_warning ("Error: %s", gai_strerror(err));
		return err;
	}
	err=1;
	for (res = res0; res; res = res->ai_next) {
		/* set a destination address that has the same type as the local address */
		if (res->ai_family==session->rtp.sockfamily ) {
		  	err=0;
		  	memcpy( &session->rtcp.rem_addr, res->ai_addr, res->ai_addrlen);
			session->rtcp.rem_addrlen=res->ai_addrlen;
		  	break;
		}
	}
	freeaddrinfo(res0);
	if (err) {
		ortp_warning("Could not set destination for RCTP socket to %s:%i.",addr,rtcp_port);
		return -1;
	}
#else
	session->rtp.rem_addrlen=sizeof(session->rtp.rem_addr);
	session->rtp.rem_addr.sin_family = AF_INET;

	err = inet_aton (addr, &session->rtp.rem_addr.sin_addr);
	if (err < 0)
	{
		ortp_warning ("Error in socket address:%s.", getSocketError());
		return err;
	}
	session->rtp.rem_addr.sin_port = htons (rtp_port);

	memcpy (&session->rtcp.rem_addr, &session->rtp.rem_addr,
		sizeof (struct sockaddr_in));
	session->rtcp.rem_addr.sin_port = htons (rtcp_port);
	session->rtcp.rem_addrlen=sizeof(session->rtcp.rem_addr);
#endif
	if (can_connect(session)){
		if (try_connect(session->rtp.socket,(struct sockaddr*)&session->rtp.rem_addr,session->rtp.rem_addrlen))
			session->flags|=RTP_SOCKET_CONNECTED;
		if (session->rtcp.socket>=0){
			if (try_connect(session->rtcp.socket,(struct sockaddr*)&session->rtcp.rem_addr,session->rtcp.rem_addrlen))
				session->flags|=RTCP_SOCKET_CONNECTED;
		}
	}else if (session->flags & RTP_SOCKET_CONNECTED){
		/*must dissolve association done by connect().
		See connect(2) manpage*/
		struct sockaddr sa;
		sa.sa_family=AF_UNSPEC;
		if (connect(session->rtp.socket,&sa,sizeof(sa))<0){
			ortp_error("Cannot dissolve connect() association for rtp socket: %s", getSocketError());
		}
		if (connect(session->rtcp.socket,&sa,sizeof(sa))<0){
			ortp_error("Cannot dissolve connect() association for rtcp socket: %s", getSocketError());
		}
		session->flags&=~RTP_SOCKET_CONNECTED;
		session->flags&=~RTCP_SOCKET_CONNECTED;
	}
	return 0;
}

int
rtp_session_set_remote_addr_and_port(RtpSession * session, const char * addr, int rtp_port, int rtcp_port){
	return rtp_session_set_remote_addr_full(session,addr,rtp_port,rtcp_port);
}

void rtp_session_set_sockets(RtpSession *session, int rtpfd, int rtcpfd)
{
	if (rtpfd>=0) set_non_blocking_socket(rtpfd);
	if (rtcpfd>=0) set_non_blocking_socket(rtcpfd);
	session->rtp.socket=rtpfd;
	session->rtcp.socket=rtcpfd;
	if (rtpfd>=0 || rtcpfd>=0 )
		session->flags|=(RTP_SESSION_USING_EXT_SOCKETS|RTP_SOCKET_CONNECTED|RTCP_SOCKET_CONNECTED);
	else session->flags&=~(RTP_SESSION_USING_EXT_SOCKETS|RTP_SOCKET_CONNECTED|RTCP_SOCKET_CONNECTED);
}

void rtp_session_set_transports(RtpSession *session, struct _RtpTransport *rtptr, struct _RtpTransport *rtcptr)
{
	session->rtp.tr = rtptr;
	session->rtcp.tr = rtcptr;
	if (rtptr)
		rtptr->session=session;
	if (rtcptr)
		rtcptr->session=session;

	if (rtptr || rtcptr )
		session->flags|=(RTP_SESSION_USING_TRANSPORT);
	else session->flags&=~(RTP_SESSION_USING_TRANSPORT);
}



/**
 *rtp_session_flush_sockets:
 *@session: a rtp session
 *
 * Flushes the sockets for all pending incoming packets.
 * This can be usefull if you did not listen to the stream for a while
 * and wishes to start to receive again. During the time no receive is made
 * packets get bufferised into the internal kernel socket structure.
 *
**/
void rtp_session_flush_sockets(RtpSession *session){
	unsigned char trash[4096];
#ifdef ORTP_INET6
	struct sockaddr_storage from;
#else
	struct sockaddr from;
#endif
	socklen_t fromlen=sizeof(from);
	if (rtp_session_using_transport(session, rtp))
	  {
		mblk_t *trashmp=esballoc(trash,sizeof(trash),0,NULL);
		
	    while (session->rtp.tr->t_recvfrom(session->rtp.tr,trashmp,0,(struct sockaddr *)&from,&fromlen)>0){};

	    if (session->rtcp.tr)
	      while (session->rtcp.tr->t_recvfrom(session->rtcp.tr,trashmp,0,(struct sockaddr *)&from,&fromlen)>0){};
		freemsg(trashmp);
	    return;
	  }

	if (session->rtp.socket>=0){
		while (recvfrom(session->rtp.socket,trash,sizeof(trash),0,(struct sockaddr *)&from,&fromlen)>0){};
	}
	if (session->rtcp.socket>=0){
		while (recvfrom(session->rtcp.socket,trash,sizeof(trash),0,(struct sockaddr*)&from,&fromlen)>0){};
	}
}


#ifdef USE_SENDMSG 
#define MAX_IOV 30
static int rtp_sendmsg(int sock,mblk_t *m, struct sockaddr *rem_addr, int addr_len){
	int error;
	struct msghdr msg;
	struct iovec iov[MAX_IOV];
	int iovlen;
	for(iovlen=0; iovlen<MAX_IOV && m!=NULL; m=m->b_cont,iovlen++){
		iov[iovlen].iov_base=m->b_rptr;
		iov[iovlen].iov_len=m->b_wptr-m->b_rptr;
	}
	if (iovlen==MAX_IOV){
		ortp_error("Too long msgb, didn't fit into iov, end discarded.");
	}
	msg.msg_name=(void*)rem_addr;
	msg.msg_namelen=addr_len;
	msg.msg_iov=&iov[0];
	msg.msg_iovlen=iovlen;
	msg.msg_control=NULL;
	msg.msg_controllen=0;
	msg.msg_flags=0;
	error=sendmsg(sock,&msg,0);
	return error;
}
#endif	

#define IP_UDP_OVERHEAD (20+8)

static void update_sent_bytes(RtpSession*s, int nbytes){
	if (s->rtp.sent_bytes==0){
		gettimeofday(&s->rtp.send_bw_start,NULL);
	}
	s->rtp.sent_bytes+=nbytes+IP_UDP_OVERHEAD;
}

static void update_recv_bytes(RtpSession*s, int nbytes){
	if (s->rtp.recv_bytes==0){
		gettimeofday(&s->rtp.recv_bw_start,NULL);
	}
	s->rtp.recv_bytes+=nbytes+IP_UDP_OVERHEAD;
}

int
rtp_session_rtp_send (RtpSession * session, mblk_t * m)
{
	int error;
	int i;
	rtp_header_t *hdr;
	struct sockaddr *destaddr=(struct sockaddr*)&session->rtp.rem_addr;
	socklen_t destlen=session->rtp.rem_addrlen;
	ortp_socket_t sockfd=session->rtp.socket;

	hdr = (rtp_header_t *) m->b_rptr;
	/* perform host to network conversions */
	hdr->ssrc = htonl (hdr->ssrc);
	hdr->timestamp = htonl (hdr->timestamp);
	hdr->seq_number = htons (hdr->seq_number);
	for (i = 0; i < hdr->cc; i++)
		hdr->csrc[i] = htonl (hdr->csrc[i]);

	if (session->flags & RTP_SOCKET_CONNECTED) {
		destaddr=NULL;
		destlen=0;
	}

	if (rtp_session_using_transport(session, rtp)){
		error = (session->rtp.tr->t_sendto) (session->rtp.tr,m,0,destaddr,destlen);
	}else{
#ifdef USE_SENDMSG
		error=rtp_sendmsg(sockfd,m,destaddr,destlen);
#else
		if (m->b_cont!=NULL)
			msgpullup(m,-1);
		error = sendto (sockfd, m->b_rptr, (int) (m->b_wptr - m->b_rptr),
			 0,destaddr,destlen);
#endif
	}
	if (error < 0){
		if (session->on_network_error.count>0){
			rtp_signal_table_emit3(&session->on_network_error,(long)"Error sending RTP packet",INT_TO_POINTER(getSocketErrorCode()));
		}else ortp_warning ("Error sending rtp packet: %s ; socket=%i", getSocketError(), sockfd);
		session->rtp.send_errno=getSocketErrorCode();
	}else{
		update_sent_bytes(session,error);
	}
	freemsg (m);
	return error;
}

int
rtp_session_rtcp_send (RtpSession * session, mblk_t * m)
{
	int error=0;
	ortp_socket_t sockfd=session->rtcp.socket;
	struct sockaddr *destaddr=(struct sockaddr*)&session->rtcp.rem_addr;
	socklen_t destlen=session->rtcp.rem_addrlen;
	bool_t using_connected_socket=(session->flags & RTCP_SOCKET_CONNECTED)!=0;

	if (using_connected_socket) {
		destaddr=NULL;
		destlen=0;
	}

	if (session->rtcp.enabled &&
		( (sockfd>=0 && (session->rtcp.rem_addrlen>0 ||using_connected_socket))
			|| rtp_session_using_transport(session, rtcp) ) ){
		if (rtp_session_using_transport(session, rtcp)){
			error = (session->rtcp.tr->t_sendto) (session->rtcp.tr, m, 0,
			destaddr, destlen);
		}
		else{
#ifdef USE_SENDMSG
			error=rtp_sendmsg(sockfd,m,destaddr, destlen);
#else
			if (m->b_cont!=NULL){
				msgpullup(m,-1);
			}
			error = sendto (sockfd, m->b_rptr,
			(int) (m->b_wptr - m->b_rptr), 0,
			destaddr, destlen);
#endif
		}
		if (error < 0){
			char host[65];
			if (session->on_network_error.count>0){
				rtp_signal_table_emit3(&session->on_network_error,(long)"Error sending RTCP packet",INT_TO_POINTER(getSocketErrorCode()));
			}else ortp_warning ("Error sending rtcp packet: %s ; socket=%i; addr=%s", getSocketError(), session->rtcp.socket, ortp_inet_ntoa((struct sockaddr*)&session->rtcp.rem_addr,session->rtcp.rem_addrlen,host,sizeof(host)) );
		}
	}else ortp_message("Not sending rtcp report: sockfd=%i, rem_addrlen=%i, connected=%i",sockfd,session->rtcp.rem_addrlen,using_connected_socket);
	freemsg (m);
	return error;
}

int
rtp_session_rtp_recv (RtpSession * session, uint32_t user_ts)
{
	int error;
	ortp_socket_t sockfd=session->rtp.socket;
#ifdef ORTP_INET6
	struct sockaddr_storage remaddr;
#else
	struct sockaddr remaddr;
#endif
	socklen_t addrlen = sizeof (remaddr);
	mblk_t *mp;
	
	if ((sockfd<0) && !rtp_session_using_transport(session, rtp)) return -1;  /*session has no sockets for the moment*/

	while (1)
	{
		int bufsz;
		bool_t sock_connected=!!(session->flags & RTP_SOCKET_CONNECTED);

		if (session->rtp.cached_mp==NULL)
			 session->rtp.cached_mp = msgb_allocator_alloc(&session->allocator,session->recv_buf_size);
		mp=session->rtp.cached_mp;
		bufsz=(int) (mp->b_datap->db_lim - mp->b_datap->db_base);
		if (sock_connected){
			error=recv(sockfd,mp->b_wptr,bufsz,0);
		}else if (rtp_session_using_transport(session, rtp)) 
			error = (session->rtp.tr->t_recvfrom)(session->rtp.tr, mp, 0,
				  (struct sockaddr *) &remaddr,
				  &addrlen);
		else error = recvfrom(sockfd, mp->b_wptr,
				  bufsz, 0,
				  (struct sockaddr *) &remaddr,
				  &addrlen);
		if (error > 0){
			if (session->symmetric_rtp && !sock_connected){
				/* store the sender rtp address to do symmetric RTP */
				memcpy(&session->rtp.rem_addr,&remaddr,addrlen);
				session->rtp.rem_addrlen=addrlen;
				if (session->use_connect){
					if (try_connect(sockfd,(struct sockaddr*)&remaddr,addrlen))
						session->flags|=RTP_SOCKET_CONNECTED;
				}
			}
			/* then parse the message and put on queue */
			mp->b_wptr+=error;
			rtp_session_rtp_parse (session, mp, user_ts, (struct sockaddr*)&remaddr,addrlen);
			session->rtp.cached_mp=NULL;
			/*for bandwidth measurements:*/
			update_recv_bytes(session,error);
		}
		else
		{
		 	int errnum=getSocketErrorCode();

			if (error == 0)
			{
				ortp_warning
					("rtp_recv: strange... recv() returned zero.");
			}
			else if (!is_would_block_error(errnum))
			{
				if (session->on_network_error.count>0){
					rtp_signal_table_emit3(&session->on_network_error,(long)"Error receiving RTP packet",INT_TO_POINTER(getSocketErrorCode()));
				}else ortp_warning("Error receiving RTP packet: %s.",getSocketError());
			}
			/* don't free the cached_mp, it will be reused next time */
			return -1;	/* avoids an infinite loop ! */
		}
	}
	return error;
}

void rtp_session_notify_inc_rtcp(RtpSession *session, mblk_t *m){
	if (session->eventqs!=NULL){
		OrtpEvent *ev=ortp_event_new(ORTP_EVENT_RTCP_PACKET_RECEIVED);
		OrtpEventData *d=ortp_event_get_data(ev);
		d->packet=m;
		rtp_session_dispatch_event(session,ev);
	}
	else freemsg(m);  /* avoid memory leak */
}

int
rtp_session_rtcp_recv (RtpSession * session)
{
	int error;
#ifdef ORTP_INET6
	struct sockaddr_storage remaddr;
#else
	struct sockaddr remaddr;
#endif
	socklen_t addrlen=0;
	mblk_t *mp;

	if (session->rtcp.socket<0 && !rtp_session_using_transport(session, rtcp)) return -1;  /*session has no rtcp sockets for the moment*/
	

	while (1)
	{
		bool_t sock_connected=!!(session->flags & RTCP_SOCKET_CONNECTED);
		if (session->rtcp.cached_mp==NULL)
			 session->rtcp.cached_mp = allocb (RTCP_MAX_RECV_BUFSIZE, 0);
		
		mp=session->rtcp.cached_mp;
		if (sock_connected){
			error=recv(session->rtcp.socket,mp->b_wptr,RTCP_MAX_RECV_BUFSIZE,0);
		}else {
			addrlen=sizeof (remaddr);

			if (rtp_session_using_transport(session, rtcp))
			  error=(session->rtcp.tr->t_recvfrom)(session->rtcp.tr, mp, 0,
				  (struct sockaddr *) &remaddr,
				  &addrlen);
			else
			  error=recvfrom (session->rtcp.socket, mp->b_wptr,
				  RTCP_MAX_RECV_BUFSIZE, 0,
				  (struct sockaddr *) &remaddr,
				  &addrlen);
		}
		if (error > 0)
		{
			mp->b_wptr += error;
			/* post an event to notify the application*/
			{
				rtp_session_notify_inc_rtcp(session,mp);
			}
			session->rtcp.cached_mp=NULL;
			if (session->symmetric_rtp && !sock_connected){
				/* store the sender rtp address to do symmetric RTP */
				memcpy(&session->rtcp.rem_addr,&remaddr,addrlen);
				session->rtcp.rem_addrlen=addrlen;
				if (session->use_connect){
					if (try_connect(session->rtcp.socket,(struct sockaddr*)&remaddr,addrlen))
						session->flags|=RTCP_SOCKET_CONNECTED;
				}
			}
		}
		else
		{
			int errnum=getSocketErrorCode();

			if (error == 0)
			{
				ortp_warning
					("rtcp_recv: strange... recv() returned zero.");
			}
			else if (!is_would_block_error(errnum))
			{
				if (session->on_network_error.count>0){
					rtp_signal_table_emit3(&session->on_network_error,(long)"Error receiving RTCP packet",INT_TO_POINTER(errnum));
				}else ortp_warning("Error receiving RTCP packet: %s.",getSocketError());
				session->rtp.recv_errno=errnum;
			}
			/* don't free the cached_mp, it will be reused next time */
			return -1;	/* avoids an infinite loop ! */
		}
	}
	return error;
}