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testdb.c revision 1.8 
      1 /*	$NetBSD: testdb.c,v 1.8 2001/03/19 15:18:59 msaitoh 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "from: @(#)testdb.c	8.1 (Berkeley) 6/6/93";
     40 #else
     41 __RCSID("$NetBSD: testdb.c,v 1.8 2001/03/19 15:18:59 msaitoh Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/file.h>
     47 #include <sys/sysctl.h>
     48 #include <err.h>
     49 #include <errno.h>
     50 #include <limits.h>
     51 #include <kvm.h>
     52 #include <db.h>
     53 #include <stdio.h>
     54 #include <stdlib.h>
     55 #include <unistd.h>
     56 #include <string.h>
     57 #include <paths.h>
     58 
     59 #include "extern.h"
     60 
     61 /* Return true if the db file is valid, else false */
     62 int
     63 testdb()
     64 {
     65 	DB *db;
     66 	int kd, ret, dbversionlen;
     67 	DBT rec;
     68 	char dbversion[_POSIX2_LINE_MAX];
     69 	char *kversion;
     70 	int mib[2];
     71 	size_t size;
     72 
     73 	ret = 0;
     74 	db = NULL;
     75 
     76 	if ((kd = open(_PATH_KMEM, O_RDONLY, 0)) < 0)
     77 		goto close;
     78 
     79 	if ((db = dbopen(_PATH_KVMDB, O_RDONLY, 0, DB_HASH, NULL)) == NULL)
     80 		goto close;
     81 
     82 	/* Read the version out of the database */
     83 	rec.data = VRS_KEY;
     84 	rec.size = sizeof(VRS_KEY) - 1;
     85 	if ((db->get)(db, &rec, &rec, 0))
     86 		goto close;
     87 	if (rec.data == 0 || rec.size == 0 || rec.size > sizeof(dbversion))
     88 		goto close;
     89 	memmove(dbversion, rec.data, rec.size);
     90 	dbversionlen = rec.size;
     91 
     92 	/* Read version string from kernel memory */
     93 	mib[0] = CTL_KERN;
     94 	mib[1] = KERN_VERSION;
     95 	if (sysctl(mib, 2, NULL, &size, NULL, 0) == -1)
     96 		errx(1, "can't get size of kernel version string");
     97 
     98 	if ((kversion = malloc(size)) == NULL)
     99 		err(1, "couldn't allocate space for buffer data");
    100 
    101 	if (sysctl(mib, 2, kversion, &size, NULL, 0) == -1)
    102 		errx(1, "can't get kernel version string");
    103 
    104 	/* If they match, we win */
    105 	ret = memcmp(dbversion, kversion, dbversionlen) == 0;
    106 
    107 close:	if (kd >= 0)
    108 		(void)close(kd);
    109 	if (db)
    110 		(void)(db->close)(db);
    111 	return (ret);
    112 }
    113