1 /* $OpenBSD: testdb.c,v 1.7 2004/11/24 17:57:16 millert 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 #ifndef lint
33 #if 0
34 static char sccsid[] = "from: @(#)testdb.c 8.1 (Berkeley) 6/6/93";
35 #else
36 static char *rcsid = "$OpenBSD: testdb.c,v 1.7 2004/11/24 17:57:16 millert Exp $";
37 #endif
38 #endif /* not lint */
39
40 #include <sys/param.h>
41 #include <sys/sysctl.h>
42
43 #include <db.h>
44 #include <fcntl.h>
45 #include <kvm.h>
46 #include <limits.h>
47 #include <paths.h>
48 #include <stdio.h>
49 #include <string.h>
50 #include <unistd.h>
51
52 #include "extern.h"
53
54 /* Return true if the db file is valid, else false */
55 int
testdb(char * dbname)56 testdb(char *dbname)
57 {
58 DBT rec;
59 DB *db = NULL;
60 size_t kversionlen;
61 char kversion[LINE_MAX];
62 int mib[2], ret = 0;
63
64 /* Read version string of running kernel */
65 mib[0] = CTL_KERN;
66 mib[1] = KERN_VERSION;
67 kversionlen = sizeof(kversion);
68 if (sysctl(mib, 2, kversion, &kversionlen, NULL, 0) < 0)
69 goto close;
70
71 /* Read the version out of the database */
72 if ((db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL)) == NULL)
73 goto close;
74 rec.data = VRS_KEY;
75 rec.size = sizeof(VRS_KEY) - 1;
76 if ((db->get)(db, &rec, &rec, 0))
77 goto close;
78 if (rec.data == NULL || rec.size > kversionlen)
79 goto close;
80
81 /* If they match, we win */
82 ret = memcmp(kversion, rec.data, rec.size) == 0;
83
84 close:
85 if (db)
86 (void)(db->close)(db);
87 return (ret);
88 }
89