/*      $NetBSD: testdb.c,v 1.10 2003/08/07 11:25:23 agc Exp $  */

/*-
* Copyright (c) 1992, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)testdb.c      8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: testdb.c,v 1.10 2003/08/07 11:25:23 agc Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <sys/sysctl.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <kvm.h>
#include <db.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <paths.h>

#include "extern.h"

/* Return true if the db file is valid, else false */
int
testdb()
{
       DB *db;
       int ret, dbversionlen;
       DBT rec;
       char dbversion[_POSIX2_LINE_MAX];
       char *kversion;
       int mib[2];
       size_t size;

       ret = 0;
       db = NULL;

       if ((db = dbopen(_PATH_KVMDB, O_RDONLY, 0, DB_HASH, NULL)) == NULL)
               goto close;

       /* Read the version out of the database */
       rec.data = VRS_KEY;
       rec.size = sizeof(VRS_KEY) - 1;
       if ((db->get)(db, &rec, &rec, 0))
               goto close;
       if (rec.data == 0 || rec.size == 0 || rec.size > sizeof(dbversion))
               goto close;
       memmove(dbversion, rec.data, rec.size);
       dbversionlen = rec.size;

       /* Read version string from kernel memory */
       mib[0] = CTL_KERN;
       mib[1] = KERN_VERSION;
       if (sysctl(mib, 2, NULL, &size, NULL, 0) == -1)
               errx(1, "can't get size of kernel version string");

       if ((kversion = malloc(size)) == NULL)
               err(1, "couldn't allocate space for buffer data");

       if (sysctl(mib, 2, kversion, &size, NULL, 0) == -1)
               errx(1, "can't get kernel version string");

       /* If they match, we win */
       ret = memcmp(dbversion, kversion, dbversionlen) == 0;

close:  if (db)
               (void)(db->close)(db);
       return (ret);
}