xref: /netbsd-src/usr.sbin/kvm_mkdb/testdb.c (revision 326b2259b73e878289ebd80cd9d20bc5aee35e99)
1 /*	$NetBSD: testdb.c,v 1.10 2003/08/07 11:25:23 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "from: @(#)testdb.c	8.1 (Berkeley) 6/6/93";
36 #else
37 __RCSID("$NetBSD: testdb.c,v 1.10 2003/08/07 11:25:23 agc Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/param.h>
42 #include <sys/file.h>
43 #include <sys/sysctl.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <limits.h>
47 #include <kvm.h>
48 #include <db.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <unistd.h>
52 #include <string.h>
53 #include <paths.h>
54 
55 #include "extern.h"
56 
57 /* Return true if the db file is valid, else false */
58 int
testdb()59 testdb()
60 {
61 	DB *db;
62 	int ret, dbversionlen;
63 	DBT rec;
64 	char dbversion[_POSIX2_LINE_MAX];
65 	char *kversion;
66 	int mib[2];
67 	size_t size;
68 
69 	ret = 0;
70 	db = NULL;
71 
72 	if ((db = dbopen(_PATH_KVMDB, O_RDONLY, 0, DB_HASH, NULL)) == NULL)
73 		goto close;
74 
75 	/* Read the version out of the database */
76 	rec.data = VRS_KEY;
77 	rec.size = sizeof(VRS_KEY) - 1;
78 	if ((db->get)(db, &rec, &rec, 0))
79 		goto close;
80 	if (rec.data == 0 || rec.size == 0 || rec.size > sizeof(dbversion))
81 		goto close;
82 	memmove(dbversion, rec.data, rec.size);
83 	dbversionlen = rec.size;
84 
85 	/* Read version string from kernel memory */
86 	mib[0] = CTL_KERN;
87 	mib[1] = KERN_VERSION;
88 	if (sysctl(mib, 2, NULL, &size, NULL, 0) == -1)
89 		errx(1, "can't get size of kernel version string");
90 
91 	if ((kversion = malloc(size)) == NULL)
92 		err(1, "couldn't allocate space for buffer data");
93 
94 	if (sysctl(mib, 2, kversion, &size, NULL, 0) == -1)
95 		errx(1, "can't get kernel version string");
96 
97 	/* If they match, we win */
98 	ret = memcmp(dbversion, kversion, dbversionlen) == 0;
99 
100 close:	if (db)
101 		(void)(db->close)(db);
102 	return (ret);
103 }
104