2 #include <sys/socket.h>
5 #include <netinet/in.h>
14 usage(const char *cmd)
17 "%s -m addr -p port [-d dst] [-i addr] [-D delay]\n", cmd);
22 main(int argc, char *argv[])
25 struct sockaddr_in in, dst;
29 memset(&in, 0, sizeof(in));
30 in.sin_family = AF_INET;
32 memset(&dst, 0, sizeof(dst));
33 dst.sin_family = AF_INET;
35 memset(&iface, 0, sizeof(iface));
38 while ((opt = getopt(argc, argv, "m:p:d:i:D:")) != -1) {
41 if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0) {
42 fprintf(stderr, "invalid -m addr %s\n", optarg);
48 in.sin_port = htons(atoi(optarg));
49 dst.sin_port = in.sin_port;
53 if (inet_pton(AF_INET, optarg, &dst.sin_addr) <= 0) {
54 fprintf(stderr, "invalid -d addr %s\n", optarg);
60 if (inet_pton(AF_INET, optarg, &iface) <= 0) {
61 fprintf(stderr, "invalid -i addr %s\n", optarg);
75 if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0)
77 if (dst.sin_addr.s_addr == 0)
78 dst.sin_addr = in.sin_addr;
80 s = socket(AF_INET, SOCK_DGRAM, 0);
82 fprintf(stderr, "socket failed: %d\n", errno);
86 if (bind(s, (const struct sockaddr *)&in, sizeof(in)) < 0) {
87 fprintf(stderr, "bind failed: %d\n", errno);
91 memset(&mreq, 0, sizeof(mreq));
92 mreq.imr_multiaddr = in.sin_addr;
93 mreq.imr_interface = iface;
94 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
95 &mreq, sizeof(mreq)) < 0) {
96 fprintf(stderr, "setsockopt IP MEMSHIP failed: %d\n", errno);
100 if (iface.s_addr != INADDR_ANY) {
101 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
102 &iface, sizeof(iface)) < 0) {
103 fprintf(stderr, "setsockopt IP IF failed: %d\n", errno);
111 n = sendto(s, &mreq, sizeof(mreq), 0,
112 (const struct sockaddr *)&dst, sizeof(dst));
114 fprintf(stderr, "sendto failed: %d\n", errno);