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 [-b ip4] -P bind_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, local_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 
31f503b4c4SSepherosa Ziehau 	memset(&local_in, 0, sizeof(local_in));
32f503b4c4SSepherosa Ziehau 	local_in.sin_family = AF_INET;
33f503b4c4SSepherosa Ziehau 
34*c4122907SSepherosa Ziehau 	reuseport = 0;
35*c4122907SSepherosa Ziehau 
36*c4122907SSepherosa Ziehau 	while ((opt = getopt(argc, argv, "4:P:b:p:r")) != -1) {
37f503b4c4SSepherosa Ziehau 		switch (opt) {
38f503b4c4SSepherosa Ziehau 		case '4':
39f503b4c4SSepherosa Ziehau 			if (inet_pton(AF_INET, optarg, &in.sin_addr) <= 0)
40f503b4c4SSepherosa Ziehau 				usage(argv[0]);
41f503b4c4SSepherosa Ziehau 			break;
42f503b4c4SSepherosa Ziehau 
43f503b4c4SSepherosa Ziehau 		case 'P':
44f503b4c4SSepherosa Ziehau 			local_in.sin_port = strtol(optarg, NULL, 10);
45f503b4c4SSepherosa Ziehau 			local_in.sin_port = htons(local_in.sin_port);
46f503b4c4SSepherosa Ziehau 			break;
47f503b4c4SSepherosa Ziehau 
48f503b4c4SSepherosa Ziehau 		case 'b':
49f503b4c4SSepherosa Ziehau 			if (inet_pton(AF_INET, optarg, &local_in.sin_addr) <= 0)
50f503b4c4SSepherosa Ziehau 				usage(argv[0]);
51f503b4c4SSepherosa Ziehau 			break;
52f503b4c4SSepherosa Ziehau 
53f503b4c4SSepherosa Ziehau 		case 'p':
54f503b4c4SSepherosa Ziehau 			in.sin_port = strtol(optarg, NULL, 10);
55f503b4c4SSepherosa Ziehau 			in.sin_port = htons(in.sin_port);
56f503b4c4SSepherosa Ziehau 			break;
57f503b4c4SSepherosa Ziehau 
58*c4122907SSepherosa Ziehau 		case 'r':
59*c4122907SSepherosa Ziehau 			reuseport = 1;
60*c4122907SSepherosa Ziehau 			break;
61*c4122907SSepherosa Ziehau 
62f503b4c4SSepherosa Ziehau 		default:
63f503b4c4SSepherosa Ziehau 			usage(argv[0]);
64f503b4c4SSepherosa Ziehau 		}
65f503b4c4SSepherosa Ziehau 	}
66f503b4c4SSepherosa Ziehau 
67f503b4c4SSepherosa Ziehau 	if (in.sin_addr.s_addr == INADDR_ANY || in.sin_port == 0 ||
68f503b4c4SSepherosa Ziehau 	    local_in.sin_port == 0)
69f503b4c4SSepherosa Ziehau 		usage(argv[0]);
70f503b4c4SSepherosa Ziehau 
71f503b4c4SSepherosa Ziehau 	s = socket(AF_INET, SOCK_DGRAM, 0);
72f503b4c4SSepherosa Ziehau 	if (s < 0)
73f503b4c4SSepherosa Ziehau 		err(2, "socket failed");
74f503b4c4SSepherosa Ziehau 
75*c4122907SSepherosa Ziehau 	if (reuseport) {
76*c4122907SSepherosa Ziehau 		if (setsockopt(s, SOL_SOCKET, SO_REUSEPORT,
77*c4122907SSepherosa Ziehau 		    &reuseport, sizeof(reuseport)) < 0)
78*c4122907SSepherosa Ziehau 			err(2, "setsockopt SO_REUSEPORT failed");
79*c4122907SSepherosa Ziehau 	}
80*c4122907SSepherosa Ziehau 
81f503b4c4SSepherosa Ziehau 	if (bind(s, (const struct sockaddr *)&local_in, sizeof(local_in)) < 0)
82f503b4c4SSepherosa Ziehau 		err(2, "bind failed");
83f503b4c4SSepherosa Ziehau 
84f503b4c4SSepherosa Ziehau 	if (connect(s, (const struct sockaddr *)&in, sizeof(in)) < 0)
85f503b4c4SSepherosa Ziehau 		err(2, "connect failed");
86f503b4c4SSepherosa Ziehau 
87f503b4c4SSepherosa Ziehau 	n = write(s, buf, sizeof(buf));
88f503b4c4SSepherosa Ziehau 	if (n < 0)
89f503b4c4SSepherosa Ziehau 		err(2, "write failed");
90f503b4c4SSepherosa Ziehau 	else if (n != (int)sizeof(buf))
91f503b4c4SSepherosa Ziehau 		errx(2, "written truncated data %d", n);
92f503b4c4SSepherosa Ziehau 
93f503b4c4SSepherosa Ziehau 	n = read(s, buf, sizeof(buf));
94f503b4c4SSepherosa Ziehau 	if (n < 0)
95f503b4c4SSepherosa Ziehau 		err(2, "read failed");
96f503b4c4SSepherosa Ziehau 	printf("read %d, done\n", n);
97f503b4c4SSepherosa Ziehau 
98f503b4c4SSepherosa Ziehau 	exit(0);
99f503b4c4SSepherosa Ziehau }
100