1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2025 Gleb Smirnoff <glebius@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30 #include <arpa/inet.h>
31 #include <net/if.h>
32 #include <assert.h>
33 #include <errno.h>
34 #include <limits.h>
35 #include <stdbool.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <err.h>
39
40 static in_port_t
atop(const char * c)41 atop(const char *c)
42 {
43 unsigned long ul;
44
45 errno = 0;
46 if ((ul = strtol(c, NULL, 10)) < 1 || ul > IPPORT_MAX || errno != 0)
47 err(1, "can't parse %s", c);
48
49 return ((in_port_t)ul);
50 }
51
52 int
main(int argc,char * argv[])53 main(int argc, char *argv[])
54 {
55 struct sockaddr_in src = {
56 .sin_family = AF_INET,
57 .sin_len = sizeof(struct sockaddr_in),
58 }, dst = {
59 .sin_family = AF_INET,
60 .sin_len = sizeof(struct sockaddr_in),
61 };
62 struct ip_mreqn mreqn;
63 struct in_addr in;
64 int s;
65 bool index;
66
67 if (argc < 7)
68 errx(1, "Usage: %s src-IPv4 src-port dst-IPv4 dst-port "
69 "interface payload", argv[0]);
70
71 if (inet_pton(AF_INET, argv[1], &src.sin_addr) != 1)
72 err(1, "inet_pton(%s) failed", argv[1]);
73 src.sin_port = htons(atop(argv[2]));
74 if (inet_pton(AF_INET, argv[3], &dst.sin_addr) != 1)
75 err(1, "inet_pton(%s) failed", argv[3]);
76 dst.sin_port = htons(atop(argv[4]));
77 if (inet_pton(AF_INET, argv[5], &in) == 1)
78 index = false;
79 else if ((mreqn.imr_ifindex = if_nametoindex(argv[5])) > 0)
80 index = true;
81 else
82 err(1, "if_nametoindex(%s) failed", argv[5]);
83
84 assert((s = socket(PF_INET, SOCK_DGRAM, 0)) > 0);
85 assert(bind(s, (struct sockaddr *)&src, sizeof(src)) == 0);
86 if (index)
87 assert(setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &mreqn,
88 sizeof(mreqn)) == 0);
89 else
90 assert(setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &in,
91 sizeof(in)) == 0);
92 if (sendto(s, argv[6], strlen(argv[6]) + 1, 0, (struct sockaddr *)&dst,
93 sizeof(dst)) != (ssize_t)strlen(argv[6]) + 1)
94 err(1, "sendto failed");
95
96 return (0);
97 }
98