1/*
2 *  Copyright (c) 2014 Spectra Logic Corporation
3 *  All rights reserved.
4 *
5 *  Redistribution and use in source and binary forms, with or without
6 *  modification, are permitted provided that the following conditions
7 *  are met:
8 *  1. Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions, and the following disclaimer,
10 *     without modification.
11 *  2. Redistributions in binary form must reproduce at minimum a disclaimer
12 *     substantially similar to the "NO WARRANTY" disclaimer below
13 *     ("Disclaimer") and any redistribution must be conditioned upon
14 *     including a substantially similar Disclaimer requirement for further
15 *     binary redistribution.
16 *
17 *  NO WARRANTY
18 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 *  HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 *  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27 *  IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 *  POSSIBILITY OF SUCH DAMAGES.
29 *
30 *  Authors: Alan Somers         (Spectra Logic Corporation)
31 *
32 * $FreeBSD: stable/11/tests/sys/netinet/udp_dontroute.c 317067 2017-04-17 20:13:20Z asomers $
33 */
34
35#include <arpa/inet.h>
36#include <netinet/in.h>
37#include <sys/types.h>
38#include <sys/socket.h>
39
40#include <err.h>
41#include <errno.h>
42#include <fcntl.h>
43#include <stdio.h>
44#include <stdbool.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49/*
50 * Sends a single UDP packet to the provided address, with SO_DONTROUTE set
51 * I couldn't find a way to do this with builtin utilities like nc(1)
52 */
53int
54main(int argc, char **argv)
55{
56	struct sockaddr_storage dst;
57	int s, t;
58	int opt;
59	int ret;
60	ssize_t len;
61	const char* sendbuf = "Hello, World!";
62	const size_t buflen = 80;
63	char recvbuf[buflen];
64	bool v6 = false;
65	const char *addr, *tapdev;
66	const uint16_t port = 46120;
67
68	bzero(&dst, sizeof(dst));
69	if (argc < 3 || argc > 4) {
70		fprintf(stderr, "Usage: %s [-6] ip_address tapdev\n", argv[0]);
71		exit(2);
72	}
73
74	if (strcmp("-6", argv[1]) == 0) {
75		v6 = true;
76		addr = argv[2];
77		tapdev = argv[3];
78	} else {
79		addr = argv[1];
80		tapdev = argv[2];
81	}
82
83	t = open(tapdev, O_RDWR | O_NONBLOCK);
84	if (t < 0)
85		err(EXIT_FAILURE, "open");
86
87	if (v6)
88		s = socket(PF_INET6, SOCK_DGRAM, 0);
89	else
90		s = socket(PF_INET, SOCK_DGRAM, 0);
91	if (s < 0)
92		err(EXIT_FAILURE, "socket");
93	opt = 1;
94
95	ret = setsockopt(s, SOL_SOCKET, SO_DONTROUTE, &opt, sizeof(opt));
96	if (ret == -1)
97		err(EXIT_FAILURE, "setsockopt(SO_DONTROUTE)");
98
99	if (v6) {
100		struct sockaddr_in6 *dst6 = ((struct sockaddr_in6*)&dst);
101
102		dst.ss_len = sizeof(struct sockaddr_in6);
103		dst.ss_family = AF_INET6;
104		dst6->sin6_port = htons(port);
105		ret = inet_pton(AF_INET6, addr, &dst6->sin6_addr);
106	} else {
107		struct sockaddr_in *dst4 = ((struct sockaddr_in*)&dst);
108
109		dst.ss_len = sizeof(struct sockaddr_in);
110		dst.ss_family = AF_INET;
111		dst4->sin_port = htons(port);
112		ret = inet_pton(AF_INET, addr, &dst4->sin_addr);
113	}
114	if (ret != 1)
115		err(EXIT_FAILURE, "inet_pton returned %d", ret);
116
117	ret = sendto(s, sendbuf, strlen(sendbuf), 0, (struct sockaddr*)&dst,
118	    dst.ss_len);
119	if (ret == -1)
120		err(EXIT_FAILURE, "sendto");
121
122	/* Verify that the packet went to the desired tap device */
123
124	len = read(t, recvbuf, buflen);
125	if (len == 0)
126		errx(EXIT_FAILURE, "read returned EOF");
127	else if (len < 0 && errno == EAGAIN)
128		errx(EXIT_FAILURE, "Did not receive any packets");
129	else if (len < 0)
130		err(EXIT_FAILURE, "read");
131
132	/*
133	 * If read returned anything at all, consider it a success.  The packet
134	 * should be an Ethernet frame containing an ARP request for
135	 * ip_address.  We won't bother to decode it
136	 */
137	return (0);
138}
139