2 #include <sys/socket.h>
5 #include <netinet/in.h>
15 usage(const char *cmd)
17 fprintf(stderr, "%s -m addr -p port -i addr [-a]\n", cmd);
22 create_sock(const struct sockaddr_in *in0, const struct in_addr *iface,
26 struct sockaddr_in in;
29 s = socket(AF_INET, SOCK_DGRAM, 0);
31 err(2, "socket failed");
34 if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &on, sizeof(on)) < 0)
35 err(2, "setsockopt SO_REUSEPORT failed");
39 in.sin_addr.s_addr = htonl(INADDR_ANY);
41 if (bind(s, (const struct sockaddr *)&in, sizeof(in)) < 0)
42 err(2, "bind failed");
44 memset(&mreq, 0, sizeof(mreq));
45 mreq.imr_multiaddr = in0->sin_addr;
46 mreq.imr_interface = *iface;
47 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
48 &mreq, sizeof(mreq)) < 0)
49 err(2, "setsockopt IP_ADD_MEMBERSHIP failed");
55 main(int argc, char *argv[])
57 struct sockaddr_in in;
59 int s1, s2, opt, n, bind_any;
62 memset(&in, 0, sizeof(in));
63 in.sin_family = AF_INET;
65 memset(&iface, 0, sizeof(iface));
68 while ((opt = getopt(argc, argv, "ai:m:p:")) != -1) {
75 if (inet_pton(AF_INET, optarg, &iface) <= 0)
80 if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0)
85 in.sin_port = strtol(optarg, NULL, 10);
86 in.sin_port = htons(in.sin_port);
94 if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0 ||
95 iface.s_addr == INADDR_ANY)
98 s1 = create_sock(&in, &iface, bind_any);
99 s2 = create_sock(&in, &iface, bind_any);
101 n = read(s1, buf, sizeof(buf));
103 err(2, "read 1 failed");
104 fprintf(stderr, "read 1 got %d\n", n);
106 n = read(s2, buf, sizeof(buf));
108 err(2, "read 2 failed");
109 fprintf(stderr, "read 2 got %d\n", n);