xref: /freebsd/sbin/dumpon/dumpon.c (revision d056fa046c6a91b90cd98165face0e42a33a5173)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static const char copyright[] =
33 "@(#) Copyright (c) 1980, 1993\n\
34 	The Regents of the University of California.  All rights reserved.\n";
35 #endif /* not lint */
36 
37 #ifndef lint
38 static char sccsid[] = "From: @(#)swapon.c	8.1 (Berkeley) 6/5/93";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/param.h>
45 #include <sys/disk.h>
46 #include <sys/sysctl.h>
47 
48 #include <err.h>
49 #include <fcntl.h>
50 #include <paths.h>
51 #include <stdint.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <sysexits.h>
56 #include <unistd.h>
57 
58 static int	verbose;
59 
60 static void
61 usage(void)
62 {
63 	fprintf(stderr, "%s\n%s\n",
64 	    "usage: dumpon [-v] special_file",
65 	    "       dumpon [-v] off");
66 	exit(EX_USAGE);
67 }
68 
69 static void
70 check_size(int fd, const char *fn)
71 {
72 	int name[] = { CTL_HW, HW_PHYSMEM };
73 	size_t namelen = sizeof name / sizeof *name;
74 	unsigned long physmem;
75 	size_t len;
76 	off_t mediasize;
77 	int minidump;
78 
79 
80 	len = sizeof minidump;
81 	if (sysctlbyname("debug.minidump", &minidump, &len, NULL, 0) == 0 &&
82 	    minidump == 1)
83 		return;
84 	len = sizeof physmem;
85 	if (sysctl(name, namelen, &physmem, &len, NULL, 0) != 0)
86 		err(EX_OSERR, "can't get memory size");
87 	if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) != 0)
88 		err(EX_OSERR, "%s: can't get size", fn);
89 	if ((uintmax_t)mediasize < (uintmax_t)physmem) {
90 		if (verbose)
91 			printf("%s is smaller than physical memory\n", fn);
92 		exit(EX_IOERR);
93 	}
94 }
95 
96 int
97 main(int argc, char *argv[])
98 {
99 	int ch;
100 	int i, fd;
101 	u_int u;
102 
103 	while ((ch = getopt(argc, argv, "v")) != -1)
104 		switch((char)ch) {
105 		case 'v':
106 			verbose = 1;
107 			break;
108 		default:
109 			usage();
110 		}
111 
112 	argc -= optind;
113 	argv += optind;
114 
115 	if (argc != 1)
116 		usage();
117 
118 	if (strcmp(argv[0], "off") != 0) {
119 		fd = open(argv[0], O_RDONLY);
120 		if (fd < 0)
121 			err(EX_OSFILE, "%s", argv[0]);
122 		check_size(fd, argv[0]);
123 		u = 0;
124 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
125 		u = 1;
126 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
127 		if (i == 0 && verbose)
128 			printf("kernel dumps on %s\n", argv[0]);
129 	} else {
130 		fd = open(_PATH_DEVNULL, O_RDONLY);
131 		if (fd < 0)
132 			err(EX_OSFILE, "%s", _PATH_DEVNULL);
133 		u = 0;
134 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
135 		if (i == 0 && verbose)
136 			printf("kernel dumps disabled\n");
137 	}
138 	if (i < 0)
139 		err(EX_OSERR, "ioctl(DIOCSKERNELDUMP)");
140 
141 	exit (0);
142 }
143