/*
  * Copyright (C) 2002-2003 Fhg Fokus
  *

  * This file is part of SEMS, a free SIP media server.

  *

  * SEMS is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version. This program is released under
  * the GPL with the additional exemption that compiling, linking,
  * and/or using OpenSSL is allowed.

  *

  * For a license to use the SEMS software under conditions

  * other than those described here, or to purchase support for this
  * software, please contact iptel.org by e-mail at the following addresses:
  *    info@iptel.org
  *

  * SEMS 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 General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License 
  * along with this program; if not, write to the Free Software 
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include "AmRtpPacket.h"
 #include "rtp/rtp.h"
 #include "log.h"

 #include "AmConfig.h"

 
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
 
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
 AmRtpPacket::AmRtpPacket()

   : data_offset(0)

 {

   // buffer will be overwritten by received packet 
   // of hdr+data - does not need to be set to 0s
   //    memset(buffer,0,4096);

 }
 
 AmRtpPacket::~AmRtpPacket()
 {
 }
 
 #ifdef SUPPORT_IPV6
 
 void AmRtpPacket::setAddr(struct sockaddr_storage* a)
 {

   memcpy(&addr,a,sizeof(sockaddr_storage));

 }
 
 void AmRtpPacket::getAddr(struct sockaddr_storage* a)
 {

   memcpy(a,&addr,sizeof(sockaddr_storage));

 }
 
 #else
 
 void AmRtpPacket::setAddr(struct sockaddr_in* a)
 {

   memcpy(&addr,a,sizeof(sockaddr_in));

 }
 
 void AmRtpPacket::getAddr(struct sockaddr_in* a)
 {

   memcpy(a,&addr,sizeof(sockaddr_in));

 }
 
 #endif
 
 int AmRtpPacket::parse()
 {

   assert(buffer);
   assert(b_size);
 
   rtp_hdr_t* hdr = (rtp_hdr_t*)buffer;

   if 
 #ifndef WITH_ZRTP
     (hdr->version != RTP_VERSION)
 #else 
     ((hdr->version != RTP_VERSION) && (hdr->version != 0))
 #endif
       {
 	DBG("received RTP packet with unsupported version (%i).\n",
 	    hdr->version);
 	return -1;
       }

   data_offset = sizeof(rtp_hdr_t) + (hdr->cc*4);
 

   if(hdr->x != 0){

 #ifndef WITH_ZRTP 

     if (AmConfig::IgnoreRTPXHdrs) {
       // skip the extension header

 #endif

       if (b_size >= data_offset + 4) {
 	data_offset +=
 	  ntohs(((rtp_xhdr_t*) (buffer + data_offset))->len)*4;
       }

 #ifndef WITH_ZRTP

     } else {
       DBG("RTP extension headers not supported.\n");
       return -1;
     }

 #endif

   }
 
   payload = hdr->pt;
   marker = hdr->m;
   sequence = ntohs(hdr->seq);
   timestamp = ntohl(hdr->ts);
   ssrc = ntohl(hdr->ssrc);
 
   if (data_offset >= b_size) {
     ERROR("bad rtp packet (header size too big) !\n");
     return -1;
   }
   d_size = b_size - data_offset;
 
   if(hdr->p){
     if (buffer[b_size-1]>=d_size){
       ERROR("bad rtp packet (invalid padding size) !\n");
       return -1;

     }

     d_size -= buffer[b_size-1];
   }

   return 0;

 }
 

 unsigned char *AmRtpPacket::getData()
 {

   return &buffer[data_offset];

 }
 

 unsigned char *AmRtpPacket::getBuffer()
 {
   return &buffer[0];
 }
 

 int AmRtpPacket::compile(unsigned char* data_buf, unsigned int size)
 {

   assert(data_buf);
   assert(size);
 
   d_size = size;
   b_size = d_size + sizeof(rtp_hdr_t);
   assert(b_size <= 4096);
   rtp_hdr_t* hdr = (rtp_hdr_t*)buffer;
 
   if(b_size>sizeof(buffer)){
     ERROR("builtin buffer size (%d) exceeded: %d\n",
 	  (int)sizeof(buffer), b_size);
     return -1;
   }
 
   memset(hdr,0,sizeof(rtp_hdr_t));
   hdr->version = RTP_VERSION;
   hdr->m = marker;
   hdr->pt = payload;

   hdr->seq = htons(sequence);
   hdr->ts = htonl(timestamp);
   hdr->ssrc = htonl(ssrc);

   data_offset = sizeof(rtp_hdr_t);
   memcpy(&buffer[data_offset],data_buf,d_size);

   return 0;

 }
 

 int AmRtpPacket::compile_raw(unsigned char* data_buf, unsigned int size)
 {
   if ((!size) || (!data_buf))
     return -1;
 
   if(size>sizeof(buffer)){
     ERROR("builtin buffer size (%d) exceeded: %d\n",
 	  (int)sizeof(buffer), size);
     return -1;
   }
 
   memcpy(&buffer[0], data_buf, size);
   b_size = size;
 
   return size;
 }
 

 int AmRtpPacket::send(int sd)
 {

   int err;

 #ifdef SUPPORT_IPV6

   if(addr.ss_family != PF_INET)
     err = sendto(sd,buffer,b_size,0,

 		 (const struct sockaddr *)&addr,

 		 sizeof(struct sockaddr_in6));
   else 

 #endif

     err = sendto(sd,buffer,b_size,0,
 		 (const struct sockaddr *)&addr,
 		 sizeof(struct sockaddr_in));

   if(err == -1){
     ERROR("while sending RTP packet: %s\n",strerror(errno));
     return -1;
   }

   return 0;

 }
 
 int AmRtpPacket::recv(int sd)
 {
 #ifdef SUPPORT_IPV6

   socklen_t recv_addr_len = sizeof(struct sockaddr_storage);

 #else

   socklen_t recv_addr_len = sizeof(struct sockaddr_in);

 #endif
 

   int ret = recvfrom(sd,buffer,sizeof(buffer),0,
 		     (struct sockaddr*)&addr,
 		     &recv_addr_len);

   if(ret > 0){

     if(ret > 4096)
       return -1;

     b_size = ret;
   }

   return ret;

 }