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      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
     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