1 /* $OpenBSD: nonxt-sendrecv.c,v 1.2 2018/05/21 01:19:21 bluhm Exp $ */
2 /*
3 * Copyright (c) Alexander Bluhm <bluhm@genua.de>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <sys/types.h>
19 #include <sys/socket.h>
20
21 #include <netdb.h>
22
23 #include <err.h>
24 #include <errno.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29
30 void __dead usage(void);
31
32 void
usage(void)33 usage(void)
34 {
35 fprintf(stderr, "usage: nonxt-sendrecv [localaddr] remoteaddr\n"
36 "Send empty protocol 59 packet and wait for answer.\n");
37 exit(1);
38 }
39
40 int
main(int argc,char * argv[])41 main(int argc, char *argv[])
42 {
43 struct addrinfo hints, *res, *res0;
44 struct timeval to;
45 const char *cause = NULL, *local, *remote;
46 int error;
47 int save_errno;
48 int s;
49 char buf[1024];
50
51 switch (argc) {
52 case 2:
53 local = NULL;
54 remote = argv[1];
55 break;
56 case 3:
57 local = argv[1];
58 remote = argv[2];
59 break;
60 default:
61 usage();
62 }
63
64 if (pledge("stdio inet dns", NULL) == -1)
65 err(1, "pledge");
66
67 /* Create socket and connect it to remote address. */
68 memset(&hints, 0, sizeof(hints));
69 hints.ai_family = AF_UNSPEC;
70 hints.ai_socktype = SOCK_RAW;
71 hints.ai_protocol = IPPROTO_NONE;
72 error = getaddrinfo(remote, NULL, &hints, &res0);
73 if (error)
74 errx(1, "getaddrinfo remote: %s", gai_strerror(error));
75 for (res = res0; res; res = res->ai_next) {
76 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
77 if (s == -1) {
78 cause = "socket";
79 continue;
80 }
81 if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
82 cause = "connect";
83 save_errno = errno;
84 close(s);
85 errno = save_errno;
86 continue;
87 }
88 break;
89 }
90 if (res == NULL)
91 err(1, "%s", cause);
92
93 /* Optionally bind the socket to local address. */
94 if (local != NULL) {
95 memset(&hints, 0, sizeof(hints));
96 hints.ai_family = res->ai_family;
97 hints.ai_socktype = SOCK_RAW;
98 hints.ai_protocol = IPPROTO_NONE;
99 hints.ai_flags = AI_PASSIVE;
100 freeaddrinfo(res0);
101 error = getaddrinfo(local, NULL, &hints, &res0);
102 if (error)
103 errx(1, "getaddrinfo local: %s", gai_strerror(error));
104 for (res = res0; res; res = res->ai_next) {
105 if (bind(s, res->ai_addr, res->ai_addrlen) == -1)
106 continue;
107 break;
108 }
109 if (res == NULL)
110 err(1, "bind");
111 }
112 freeaddrinfo(res0);
113
114 if (pledge("stdio inet", NULL) == -1)
115 err(1, "pledge");
116
117 /* Send a protocol 59 packet. */
118 if (send(s, buf, 0, 0) == -1)
119 err(1, "send");
120 /* Wait for up to 3 seconds to receive a reply packet. */
121 to.tv_sec = 3;
122 to.tv_usec = 0;
123 if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &to, sizeof(to)) == -1)
124 err(1, "setsockopt");
125 if (recv(s, buf, sizeof(buf), 0) == -1)
126 err(1, "recv");
127
128 return 0;
129 }
130