#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
static 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);
}