xref: /freebsd/sbin/dumpon/dumpon.c (revision e627b39baccd1ec9129690167cf5e6d860509655)
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 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 /*static char sccsid[] = "From: @(#)swapon.c	8.1 (Berkeley) 6/5/93";*/
42 static const char rcsid[] =
43 	"$Id: dumpon.c,v 1.1 1995/05/12 19:10:09 wollman Exp $";
44 #endif /* not lint */
45 
46 #include <errno.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 #include <sys/param.h>
51 #include <sys/types.h>
52 #include <sys/sysctl.h>
53 #include <sys/stat.h>
54 #include <sysexits.h>
55 #include <err.h>
56 
57 void	usage __P((void)) __dead2;
58 static char *whoami;
59 
60 int
61 main(int argc, char **argv)
62 {
63 	extern char *optarg;
64 	extern int optind;
65 	int ch, verbose, rv;
66 	struct stat stab;
67 	int mib[2];
68 
69 	verbose = rv = 0;
70 	whoami = argv[0];
71 	while ((ch = getopt(argc, argv, "v")) != EOF)
72 		switch((char)ch) {
73 		case 'v':
74 			verbose = 1;
75 			break;
76 		case '?':
77 		default:
78 			usage();
79 		}
80 	argv += optind;
81 
82 	if (!argv[0] || argv[1])
83 		usage();
84 
85 	if (strcmp(argv[0], "off")) {
86 		rv = stat(argv[0], &stab);
87 		if (rv) {
88 			err(EX_OSFILE, "%s", argv[0]);
89 		}
90 
91 		if (!S_ISBLK(stab.st_mode)) {
92 			errx(EX_USAGE, "%s: must specify a block device",
93 			     argv[0]);
94 		}
95 	} else {
96 		stab.st_rdev = NODEV;
97 	}
98 
99 	mib[0] = CTL_KERN;
100 	mib[1] = KERN_DUMPDEV;
101 
102 	rv = sysctl(mib, 2, (void *)0, (size_t *)0, &stab.st_rdev,
103 		    sizeof stab.st_rdev);
104 	if (rv) {
105 		err(EX_OSERR, "sysctl: kern.dumpdev");
106 	}
107 
108 	if (verbose) {
109 		if (stab.st_rdev == NODEV) {
110 			printf("%s: crash dumps disabled\n", whoami);
111 		} else {
112 			printf("%s: crash dumps to %s (%lu, %lu)\n",
113 			       whoami, argv[0],
114 			       (unsigned long)major(stab.st_rdev),
115 			       (unsigned long)minor(stab.st_rdev));
116 		}
117 	}
118 
119 	return 0;
120 }
121 
122 void
123 usage()
124 {
125 	fprintf(stderr,
126 		"usage: %s [-v] special_file\n"
127 		"       %s [-v] off\n", whoami, whoami);
128 	exit(EX_USAGE);
129 }
130