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
44 int
main(int argc,char * argv[])45 main(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