2 #include <sys/socket.h>
5 #include <netinet/in.h>
15 usage(const char *cmd)
17 fprintf(stderr, "%s -4 ip4 -p port [-r]\n", cmd);
22 main(int argc, char *argv[])
24 struct sockaddr_in in;
25 int s, opt, n, reuseport;
28 memset(&in, 0, sizeof(in));
29 in.sin_family = AF_INET;
33 while ((opt = getopt(argc, argv, "4:p:r")) != -1) {
36 if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0)
41 in.sin_port = strtol(optarg, NULL, 10);
42 in.sin_port = htons(in.sin_port);
54 if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0)
57 s = socket(AF_INET, SOCK_DGRAM, 0);
59 err(2, "socket failed");
62 if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
63 &reuseport, sizeof(reuseport)) < 0)
64 err(2, "setsockopt SO_REUSEPORT failed");
67 n = sendto(s, buf, sizeof(buf), 0,
68 (const struct sockaddr *)&in, sizeof(in));
70 err(2, "sendto failed");
71 else if (n != (int)sizeof(buf))
72 errx(2, "sent truncated data %d", n);
74 n = read(s, buf, sizeof(buf));
76 err(2, "read failed");
77 printf("read %d, done\n", n);