1/*-
2 * Copyright (c) 2008 Bruce Simpson.
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 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/param.h>
28#include <sys/types.h>
29#include <sys/ioctl.h>
30
31#include <stdlib.h>
32#include <stdio.h>
33#include <string.h>
34#include <errno.h>
35#include <err.h>
36#include <fcntl.h>
37#include <unistd.h>
38
39#include <libgen.h>
40#include <sysexits.h>
41
42#define DEVPATHNAME "/dev"
43
44int
45main(int argc, char *argv[])
46{
47	char *progname;
48	char *ttyname;
49	int fd;
50	int dofree;
51
52	dofree = 0;
53
54	progname = basename(argv[0]);
55	if (argc != 2)
56		errx(EX_USAGE, "usage: %s <ttyname>\n", progname);
57	if (geteuid() != 0)
58		errx(EX_NOPERM, "Sorry\n");
59
60	if (argv[1][0] == '/') {
61		ttyname = argv[1];
62	} else {
63		size_t len, maxpath, result;
64
65		len = strlen(argv[1]) + sizeof(DEVPATHNAME) + 1;
66
67		maxpath = pathconf(DEVPATHNAME, _PC_PATH_MAX);
68		if (len > maxpath) {
69			warnc(ENAMETOOLONG, ttyname);
70			exit(EX_DATAERR);
71		}
72
73		ttyname = malloc(len);
74		if (ttyname == NULL) {
75			warnc(ENOMEM, "malloc");
76			exit(EX_OSERR);
77		}
78		dofree = 1;
79
80		result = snprintf(ttyname, len, "%s/%s", DEVPATHNAME, argv[1]);
81		if (result >= len)
82			warnc(ENOMEM, "snprintf");
83	}
84
85	fd = open(ttyname, O_RDWR);
86	if (fd == -1) {
87		warnc(errno, "open %s", ttyname);
88		if (dofree)
89			free(ttyname);
90		exit(EX_OSERR);
91	}
92
93	if (0 != ioctl(fd, TIOCNXCL, 0))
94		warnc(errno, "ioctl TIOCNXCL %s", ttyname);
95
96	if (dofree)
97		free(ttyname);
98	exit(0);
99}
100