testcases/network/multicast/mc_commo/mc_recv.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 <netdb.h>

#define	MAXBUFSIZ	8096

char buf[MAXBUFSIZ];

int main(int argc, char *argv[])
{
	struct ip_mreq imr;
        struct sockaddr_in from_in, mcast_in;
        int s=0, n=0, one=1;
	/*DHH 052697 Added for 64BIT Compatibility */
/*	6/2/97	Mario Gallegos changed from ifdef to ifndef (PORTING)	*/
#ifndef __64BIT__
	unsigned int len=0;
#else
	unsigned long len=0;
#endif
        unsigned i1, i2, i3, i4, g1, g2, g3, g4;
        struct hostent *hp, *gethostbyname();

        /*int loop=0;*/

  	if (argc < 4) {
           fprintf(stderr,
                   "usage: %s g.g.g.g interface_name (or i.i.i.i) port\n",
                   argv[ 0]);
           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 group interface address\n");
               exit (1);
           } else
               imr.imr_interface.s_addr = htonl((i1<<24) | (i2<<16) | (i3<<8) | i4);

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

        memset(&mcast_in, 0x00, sizeof(mcast_in));
        mcast_in.sin_family = AF_INET;
        mcast_in.sin_port = htons(atoi(argv[3]));

        /* allow address reuse for binding multiple multicast applications to
           the same group */
        if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) {
           perror("setsockopt SO_REUSEADDR failed");
           exit(1);
        }

        if (bind(s, ( struct sockaddr *) &mcast_in, sizeof (mcast_in)) < 0) {
           perror("bind");
           exit(1);
        }

        /* Add interface to multicast group */
        if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof(struct ip_mreq)) < 0) {
            perror("can not join group");
            exit (1);
	}
        printf ("Joined group\n");

        /* Receive datagrams */
        len = sizeof (from_in);
        for (;;) {
            memset(&from_in, 0x00, sizeof(from_in));
            if ((n = recvfrom(s, buf, sizeof(buf), 0, (struct sockaddr *) &from_in, &len)) < 0)
            {
               perror("recvfrom");
               exit(1);
            }
            if (strcmp (buf,"quit") == 0)
               break;
            printf ("%s\n",buf);
        }
        close (s);
        exit (0);
}