xref: /freebsd/sbin/dumpon/dumpon.c (revision 243e928310d073338c5ec089f0dce238a80b9866)
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 <errno.h>
50 #include <fcntl.h>
51 #include <paths.h>
52 #include <stdint.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <sysexits.h>
57 #include <unistd.h>
58 
59 static int	verbose;
60 
61 static void
62 usage(void)
63 {
64 	fprintf(stderr, "%s\n%s\n%s\n",
65 	    "usage: dumpon [-v] special_file",
66 	    "       dumpon [-v] off",
67 	    "       dumpon [-v] -l");
68 	exit(EX_USAGE);
69 }
70 
71 static void
72 check_size(int fd, const char *fn)
73 {
74 	int name[] = { CTL_HW, HW_PHYSMEM };
75 	size_t namelen = nitems(name);
76 	unsigned long physmem;
77 	size_t len;
78 	off_t mediasize;
79 	int minidump;
80 
81 	len = sizeof(minidump);
82 	if (sysctlbyname("debug.minidump", &minidump, &len, NULL, 0) == 0 &&
83 	    minidump == 1)
84 		return;
85 	len = sizeof(physmem);
86 	if (sysctl(name, namelen, &physmem, &len, NULL, 0) != 0)
87 		err(EX_OSERR, "can't get memory size");
88 	if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) != 0)
89 		err(EX_OSERR, "%s: can't get size", fn);
90 	if ((uintmax_t)mediasize < (uintmax_t)physmem) {
91 		if (verbose)
92 			printf("%s is smaller than physical memory\n", fn);
93 		exit(EX_IOERR);
94 	}
95 }
96 
97 static void
98 listdumpdev(void)
99 {
100 	char dumpdev[PATH_MAX];
101 	size_t len;
102 	const char *sysctlname = "kern.shutdown.dumpdevname";
103 
104 	len = sizeof(dumpdev);
105 	if (sysctlbyname(sysctlname, &dumpdev, &len, NULL, 0) != 0) {
106 		if (errno == ENOMEM) {
107 			err(EX_OSERR, "Kernel returned too large of a buffer for '%s'\n",
108 				sysctlname);
109 		} else {
110 			err(EX_OSERR, "Sysctl get '%s'\n", sysctlname);
111 		}
112 	}
113 	if (verbose) {
114 		printf("kernel dumps on ");
115 	}
116 	if (strlen(dumpdev) == 0) {
117 		printf("%s\n", _PATH_DEVNULL);
118 	} else {
119 		printf("%s\n", dumpdev);
120 	}
121 }
122 
123 int
124 main(int argc, char *argv[])
125 {
126 	int ch;
127 	int i, fd;
128 	u_int u;
129 	int do_listdumpdev = 0;
130 
131 	while ((ch = getopt(argc, argv, "lv")) != -1)
132 		switch((char)ch) {
133 		case 'l':
134 			do_listdumpdev = 1;
135 			break;
136 		case 'v':
137 			verbose = 1;
138 			break;
139 		default:
140 			usage();
141 		}
142 
143 	argc -= optind;
144 	argv += optind;
145 
146 	if (do_listdumpdev) {
147 		listdumpdev();
148 		exit(EX_OK);
149 	}
150 
151 	if (argc != 1)
152 		usage();
153 
154 	if (strcmp(argv[0], "off") != 0) {
155 		char tmp[PATH_MAX];
156 		char *dumpdev;
157 
158 		if (strncmp(argv[0], _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0) {
159 			dumpdev = argv[0];
160 		} else {
161 			i = snprintf(tmp, PATH_MAX, "%s%s", _PATH_DEV, argv[0]);
162 			if (i < 0) {
163 				err(EX_OSERR, "%s", argv[0]);
164 			} else if (i >= PATH_MAX) {
165 				errno = EINVAL;
166 				err(EX_DATAERR, "%s", argv[0]);
167 			}
168 			dumpdev = tmp;
169 		}
170 		fd = open(dumpdev, O_RDONLY);
171 		if (fd < 0)
172 			err(EX_OSFILE, "%s", dumpdev);
173 		check_size(fd, dumpdev);
174 		u = 0;
175 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
176 		u = 1;
177 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
178 		if (i == 0 && verbose)
179 			printf("kernel dumps on %s\n", dumpdev);
180 	} else {
181 		fd = open(_PATH_DEVNULL, O_RDONLY);
182 		if (fd < 0)
183 			err(EX_OSFILE, "%s", _PATH_DEVNULL);
184 		u = 0;
185 		i = ioctl(fd, DIOCSKERNELDUMP, &u);
186 		if (i == 0 && verbose)
187 			printf("kernel dumps disabled\n");
188 	}
189 	if (i < 0)
190 		err(EX_OSERR, "ioctl(DIOCSKERNELDUMP)");
191 
192 	exit (0);
193 }
194