xref: /freebsd/sbin/dumpon/dumpon.c (revision 817420dc8eac7df799c78f5309b75092b7f7cd40)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1980, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "From: @(#)swapon.c	8.1 (Berkeley) 6/5/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <err.h>
49 #include <stdio.h>
50 #include <unistd.h>
51 #include <sys/param.h>
52 #include <sys/sysctl.h>
53 #include <sys/stat.h>
54 #include <sysexits.h>
55 
56 void	usage __P((void)) __dead2;
57 
58 int
59 main(int argc, char **argv)
60 {
61 	int ch, verbose, rv;
62 	struct stat stab;
63 	int mib[2];
64 
65 	verbose = rv = 0;
66 	while ((ch = getopt(argc, argv, "v")) != -1)
67 		switch((char)ch) {
68 		case 'v':
69 			verbose = 1;
70 			break;
71 		case '?':
72 		default:
73 			usage();
74 		}
75 	argv += optind;
76 
77 	if (!argv[0] || argv[1])
78 		usage();
79 
80 	if (strcmp(argv[0], "off")) {
81 		rv = stat(argv[0], &stab);
82 		if (rv) {
83 			err(EX_OSFILE, "%s", argv[0]);
84 		}
85 
86 		if (!S_ISCHR(stab.st_mode)) {
87 			errx(EX_USAGE,
88 			     "%s: must specify a character disk device",
89 			     argv[0]);
90 		}
91 	} else {
92 		stab.st_rdev = NODEV;
93 	}
94 
95 	mib[0] = CTL_KERN;
96 	mib[1] = KERN_DUMPDEV;
97 
98 	rv = sysctl(mib, 2, (void *)0, (size_t *)0, &stab.st_rdev,
99 		    sizeof stab.st_rdev);
100 	if (rv) {
101 		err(EX_OSERR, "sysctl: kern.dumpdev");
102 	}
103 
104 	if (verbose) {
105 		if (stab.st_rdev == NODEV) {
106 			printf("dumpon: crash dumps disabled\n");
107 		} else {
108 			printf("dumpon: crash dumps to %s (%lu, %lu)\n",
109 			       argv[0],
110 			       (unsigned long)major(stab.st_rdev),
111 			       (unsigned long)minor(stab.st_rdev));
112 		}
113 	}
114 
115 	return 0;
116 }
117 
118 void
119 usage()
120 {
121 	fprintf(stderr,
122 		"usage: dumpon [-v] special_file\n"
123 		"       dumpon [-v] off\n");
124 	exit(EX_USAGE);
125 }
126