1f503b4c4SSepherosa Ziehau #include <sys/types.h>
2f503b4c4SSepherosa Ziehau #include <sys/socket.h>
3f503b4c4SSepherosa Ziehau 
4f503b4c4SSepherosa Ziehau #include <arpa/inet.h>
5f503b4c4SSepherosa Ziehau #include <netinet/in.h>
6f503b4c4SSepherosa Ziehau 
7f503b4c4SSepherosa Ziehau #include <err.h>
8f503b4c4SSepherosa Ziehau #include <stdio.h>
9f503b4c4SSepherosa Ziehau #include <stdint.h>
10f503b4c4SSepherosa Ziehau #include <stdlib.h>
11f503b4c4SSepherosa Ziehau #include <string.h>
12f503b4c4SSepherosa Ziehau #include <unistd.h>
13f503b4c4SSepherosa Ziehau 
14f503b4c4SSepherosa Ziehau static void
usage(const char * cmd)15f503b4c4SSepherosa Ziehau usage(const char *cmd)
16f503b4c4SSepherosa Ziehau {
17*c4122907SSepherosa Ziehau 	fprintf(stderr, "%s -4 ip4 -p port [-r]\n", cmd);
18f503b4c4SSepherosa Ziehau 	exit(1);
19f503b4c4SSepherosa Ziehau }
20f503b4c4SSepherosa Ziehau 
21f503b4c4SSepherosa Ziehau int
main(int argc,char * argv[])22f503b4c4SSepherosa Ziehau main(int argc, char *argv[])
23f503b4c4SSepherosa Ziehau {
24f503b4c4SSepherosa Ziehau 	struct sockaddr_in in;
25*c4122907SSepherosa Ziehau 	int s, opt, n, reuseport;
26f503b4c4SSepherosa Ziehau 	uint8_t buf[18];
27f503b4c4SSepherosa Ziehau 
28f503b4c4SSepherosa Ziehau 	memset(&in, 0, sizeof(in));
29f503b4c4SSepherosa Ziehau 	in.sin_family = AF_INET;
30f503b4c4SSepherosa Ziehau 
31*c4122907SSepherosa Ziehau 	reuseport = 0;
32*c4122907SSepherosa Ziehau 
33*c4122907SSepherosa Ziehau 	while ((opt = getopt(argc, argv, "4:p:r")) != -1) {
34f503b4c4SSepherosa Ziehau 		switch (opt) {
35f503b4c4SSepherosa Ziehau 		case '4':
36f503b4c4SSepherosa Ziehau 			if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0)
37f503b4c4SSepherosa Ziehau 				usage(argv[0]);
38f503b4c4SSepherosa Ziehau 			break;
39f503b4c4SSepherosa Ziehau 
40f503b4c4SSepherosa Ziehau 		case 'p':
41f503b4c4SSepherosa Ziehau 			in.sin_port = strtol(optarg, NULL, 10);
42f503b4c4SSepherosa Ziehau 			in.sin_port = htons(in.sin_port);
43f503b4c4SSepherosa Ziehau 			break;
44f503b4c4SSepherosa Ziehau 
45*c4122907SSepherosa Ziehau 		case 'r':
46*c4122907SSepherosa Ziehau 			reuseport = 1;
47*c4122907SSepherosa Ziehau 			break;
48*c4122907SSepherosa Ziehau 
49f503b4c4SSepherosa Ziehau 		default:
50f503b4c4SSepherosa Ziehau 			usage(argv[0]);
51f503b4c4SSepherosa Ziehau 		}
52f503b4c4SSepherosa Ziehau 	}
53f503b4c4SSepherosa Ziehau 
54f503b4c4SSepherosa Ziehau 	if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0)
55f503b4c4SSepherosa Ziehau 		usage(argv[0]);
56f503b4c4SSepherosa Ziehau 
57f503b4c4SSepherosa Ziehau 	s = socket(AF_INET, SOCK_DGRAM, 0);
58f503b4c4SSepherosa Ziehau 	if (s < 0)
59f503b4c4SSepherosa Ziehau 		err(2, "socket failed");
60f503b4c4SSepherosa Ziehau 
61*c4122907SSepherosa Ziehau 	if (reuseport) {
62*c4122907SSepherosa Ziehau 		if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
63*c4122907SSepherosa Ziehau 		    &reuseport, sizeof(reuseport)) < 0)
64*c4122907SSepherosa Ziehau 			err(2, "setsockopt SO_REUSEPORT failed");
65*c4122907SSepherosa Ziehau 	}
66*c4122907SSepherosa Ziehau 
67f503b4c4SSepherosa Ziehau 	n = sendto(s, buf, sizeof(buf), 0,
68f503b4c4SSepherosa Ziehau 	    (const struct sockaddr *)&in, sizeof(in));
69f503b4c4SSepherosa Ziehau 	if (n < 0)
70f503b4c4SSepherosa Ziehau 		err(2, "sendto failed");
71f503b4c4SSepherosa Ziehau 	else if (n != (int)sizeof(buf))
72f503b4c4SSepherosa Ziehau 		errx(2, "sent truncated data %d", n);
73f503b4c4SSepherosa Ziehau 
74f503b4c4SSepherosa Ziehau 	n = read(s, buf, sizeof(buf));
75f503b4c4SSepherosa Ziehau 	if (n < 0)
76f503b4c4SSepherosa Ziehau 		err(2, "read failed");
77f503b4c4SSepherosa Ziehau 	printf("read %d, done\n", n);
78f503b4c4SSepherosa Ziehau 
79f503b4c4SSepherosa Ziehau 	exit(0);
80f503b4c4SSepherosa Ziehau }
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