2 #include <sys/socket.h>
5 #include <netinet/in.h>
16 usage(const char *cmd)
18 fprintf(stderr, "%s -4 ip4 -p port [-r]\n", cmd);
23 main(int argc, char *argv[])
25 struct sockaddr_in in, in2;
26 int s, opt, n, reuseport;
29 memset(&in, 0, sizeof(in));
30 in.sin_family = AF_INET;
34 while ((opt = getopt(argc, argv, "4:p:r")) != -1) {
37 if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0)
42 in.sin_port = strtol(optarg, NULL, 10);
43 in.sin_port = htons(in.sin_port);
55 if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0)
58 s = socket(AF_INET, SOCK_DGRAM, 0);
60 err(2, "socket failed");
63 if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
64 &reuseport, sizeof(reuseport)) < 0)
65 err(2, "setsockopt SO_REUSEPORT failed");
68 if (connect(s, (const struct sockaddr *)&in, sizeof(in)) < 0)
69 err(2, "connect failed");
71 memset(&in2, 0, sizeof(in2));
72 in2.sin_family = AF_UNSPEC;
73 if (connect(s, (const struct sockaddr *)&in2, sizeof(in2)) < 0) {
76 if (error != EAFNOSUPPORT)
77 errc(2, error, "di-connect failed");
80 n = sendto(s, buf, sizeof(buf), 0,
81 (const struct sockaddr *)&in, sizeof(in));
83 err(2, "sendto failed");
84 else if (n != (int)sizeof(buf))
85 errx(2, "sent truncated data %d", n);
87 n = read(s, buf, sizeof(buf));
89 err(2, "read failed");
90 printf("read %d, done\n", n);