/*
NAME:       Multicast sender
SYNOPSIS:    McastSend <multicast group> <port>
DESCRIPTION:    The program creates a datagram socket in the inet 
                domain. It sends data to a multicast group and gets
                an echo of the message.
*/

#include <stdio.h>
#include <errno.h>
#include <sys/time.h>

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/file.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>

#include "packetReg.h"

int main( int argc, char * argv[] )
{
   int   s;
   struct   sockaddr_in mc_group;
   struct sockaddr_in addr;
   int rc;
   /* linux */
   unsigned long int GroupIP;
   /* Solaris
      in_addr_t GroupIP; */
   char loop, ttl;
   Packet pkt;

   if (argc != 4) {
     fprintf(stderr, "Usage : %s <name> <multicast group> <port>\n",argv[0]);
     exit(0);
   }

   if( (GroupIP = inet_addr(argv[2]))== -1)
       printf("error in inet_addr\n");
   
   strcpy(pkt.name, argv[1]);

   mc_group.sin_family = AF_INET; 
   mc_group.sin_port = htons(atoi(argv[3]));
   mc_group.sin_addr.s_addr = GroupIP;

   s = socket (PF_INET,SOCK_DGRAM,0);

   /*
      By default, messages sent to the multicast group are looped 
      back to the local host. this function disables that.
      loop = 1  means enable loopback 
      loop = 0  means disable loopback 
      NOTE : by default, loopback is enabled
      */       
   loop = 1;
   if( setsockopt(s,IPPROTO_IP,IP_MULTICAST_LOOP,(char *) &loop,
		  sizeof(u_char)) == -1 )
   {
     printf("error in setting loopback\n");
   }

   /*
      set the Time-To-Live value
      */
   ttl = 5;
   if( setsockopt(s,IPPROTO_IP,IP_MULTICAST_TTL,(char *) &ttl,
		  sizeof(u_char)) == -1 )
   {
     printf("error in setting loopback value\n");
   }

   for(;;) {
     printf("\nType anything followed by RETURN, or type CTRL-D to exit\n");
     rc=read(0,pkt.msg, BUFSIZE);
     if (rc == 0) break;
     pkt.msg[rc-1]='\0';
     pkt.length = sizeof(pkt)-BUFSIZE+rc;
     printf("Sending %d bytes \"%s\"\n", pkt.length, pkt.msg);
     if (sendto(s, (char *)&pkt, pkt.length, 0, (struct sockaddr*)&mc_group, 
		sizeof(mc_group)) <0 )
	 perror("sending datagram message");
   }
   printf ("EOF... exit\n");
   close(s);
}