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/* $OpenBSD: testdb.c,v 1.3 1998/08/19 06:47:55 millert 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)testdb.c 8.1 (Berkeley) 6/6/93";
#else
static char *rcsid = "$OpenBSD: testdb.c,v 1.3 1998/08/19 06:47:55 millert Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/file.h>
#include <errno.h>
#include <limits.h>
#include <kvm.h>
#include <db.h>
#include <stdio.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(dbname)
char *dbname;
{
register DB *db;
register int cc, kd, ret, dbversionlen;
DBT rec;
struct nlist nitem;
char dbversion[_POSIX2_LINE_MAX];
char kversion[_POSIX2_LINE_MAX];
ret = 0;
db = NULL;
if ((kd = open(_PATH_KMEM, O_RDONLY, 0)) < 0)
goto close;
if ((db = dbopen(dbname, 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;
(void)memcpy(dbversion, rec.data, rec.size);
dbversionlen = rec.size;
/* Read version string from kernel memory */
rec.data = VRS_SYM;
rec.size = sizeof(VRS_SYM) - 1;
if ((db->get)(db, &rec, &rec, 0))
goto close;
if (rec.data == 0 || rec.size != sizeof(struct nlist))
goto close;
(void)memcpy(&nitem, rec.data, sizeof(nitem));
/*
* Theoretically possible for lseek to be seeking to -1. Not
* that it's something to lie awake nights about, however.
*/
errno = 0;
if (lseek(kd, (off_t)nitem.n_value, SEEK_SET) == -1 && errno != 0)
goto close;
cc = read(kd, kversion, sizeof(kversion));
if (cc < 0 || cc != sizeof(kversion))
goto close;
/* If they match, we win */
ret = memcmp(kversion, dbversion, dbversionlen) == 0;
close: if (kd >= 0)
(void)close(kd);
if (db)
(void)(db->close)(db);
return (ret);
}
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