testcases/network/multicast/mc_commo/mc_send.c

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <netdb.h>

#define	MAXBUFSIZ	8096

char buf[MAXBUFSIZ];
int Num_Loops=100;

int main(argc, argv)
int argc;
char *argv[];
{
	struct ip_mreq imr;
        struct sockaddr_in sin, mcast_out;
        int i=0, s=0, n=0;
        unsigned i1, i2, i3, i4, g1, g2, g3, g4;
        struct hostent *hp, *gethostbyname();
        char myname[64];
	char ttl=0;

  	if (argc < 4) {
           fprintf(stderr,
                   "usage: %s g.g.g.g interface_name (or i.i.i.i) port [ttl]\n",
                   argv[ 0]);
           exit( 1);
        }

        /* Get local host name */
        if (gethostname(myname, sizeof (myname) - 1) < 0) {
          perror("gethostname");
          exit(1);
        }

        /* set up multicast membership structure */
        if ((n = sscanf(argv[1], "%u.%u.%u.%u", &g1, &g2, &g3, &g4)) != 4) {
          fprintf(stderr, "bad group address\n" );
          exit(1);
        }
        imr.imr_multiaddr.s_addr = htonl((g1<<24) | (g2<<16) | (g3<<8) | g4);

        if ((hp = gethostbyname(argv[2]))) {
           memcpy(&imr.imr_interface.s_addr, hp->h_addr, hp->h_length);
        } else
           if ((n = sscanf(argv[2], "%u.%u.%u.%u", &i1, &i2, &i3, &i4)) != 4) {
               fprintf (stderr,"Bad interface address\n");
               exit (1);
           } else
              imr.imr_interface.s_addr =
                                     htonl((i1<<24) | (i2<<16) | (i3<<8) | i4);

        /* Set up socket structure for sendto */
        memset(&mcast_out, 0x00, sizeof(mcast_out));
        memset(&sin, 0x00, sizeof(sin));
        mcast_out.sin_family = sin.sin_family = AF_INET;
        mcast_out.sin_port = sin.sin_port = htons(atoi(argv[3]));

        mcast_out.sin_addr.s_addr = imr.imr_multiaddr.s_addr;

        /* Create socket */
        if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
            perror( "can not open socket" );
            exit(1);
        }

        /* Set socket for multicasting */
        if ( setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
             &imr.imr_interface.s_addr, sizeof(imr.imr_interface.s_addr)) != 0 )
        {
           fprintf (stderr,
                    "Error: unable to set socket option IP_MULTICAST_IF\n");
           exit (1);
        }

        /* With an even port number the loopback will be disabled */
/*      loop = atoi(argv[3])&1;
        if (setsockopt(s,IPPROTO_IP,IP_MULTICAST_LOOP,&loop,sizeof(char))!= 0) {
           fprintf (stderr,
                    "Error: unable to set socket option IP_MULTICAST_LOOP\n");
           exit (1);
        }
*/
	ttl = atoi(argv[4]);
	if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
	{
		perror("can not set ttl");
		exit(1);
	}

        /* Send datagrams */
        for (i=1;i < Num_Loops;i++) {
            sprintf(buf, "%s %d %d", argv[2], i, (int)time(0));
            if ((n = sendto(s, buf, sizeof(buf), 0, (struct sockaddr *) &mcast_out,
                          sizeof(mcast_out))) < 0) {
               perror("setsockopt");
               exit(1);
            }
            sleep (1);
        }

        /* Tell recevier to close */
        sprintf(buf, "quit");
        if ((n = sendto(s, buf, sizeof(buf), 0, (struct sockaddr *) &mcast_out,
                        sizeof(mcast_out))) < 0) {
           perror("setsockopt");
           exit(1);
        }

        close (s);
        exit (0);
}