1 /* $OpenBSD: nologin.c,v 1.10 2023/03/08 04:43:06 guenther Exp $ */
2
3 /*
4 * Copyright (c) 1997, Jason Downs. All rights reserved.
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(S) ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * 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/types.h>
29 #include <err.h>
30 #include <fcntl.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 /* Distinctly different from _PATH_NOLOGIN. */
37 #define _PATH_NOLOGIN_TXT "/etc/nologin.txt"
38
39 #define DEFAULT_MESG "This account is currently not available.\n"
40
41 int
main(int argc,char * argv[])42 main(int argc, char *argv[])
43 {
44 int nfd;
45 ssize_t nrd;
46 char nbuf[BUFSIZ];
47
48 if (unveil(_PATH_NOLOGIN_TXT, "r") == -1)
49 err(1, "unveil %s", _PATH_NOLOGIN_TXT);
50 if (pledge("stdio rpath", NULL) == -1)
51 err(1, "pledge");
52
53 nfd = open(_PATH_NOLOGIN_TXT, O_RDONLY);
54 if (nfd == -1) {
55 write(STDOUT_FILENO, DEFAULT_MESG, strlen(DEFAULT_MESG));
56 exit (1);
57 }
58
59 while ((nrd = read(nfd, nbuf, sizeof(nbuf))) != -1 && nrd != 0)
60 write(STDOUT_FILENO, nbuf, nrd);
61 close (nfd);
62
63 exit (1);
64 }
65