/* $NetBSD: disklabel_scan.c,v 1.3 2009/01/18 12:13:03 lukem Exp $ */

/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Roland C. Dowdeswell.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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
__COPYRIGHT(
"@(#) Copyright (c) 2002\
       The NetBSD Foundation, Inc.  All rights reserved.");
__RCSID("$NetBSD: disklabel_scan.c,v 1.3 2009/01/18 12:13:03 lukem Exp $");
#endif

#include <string.h>
#include <unistd.h>
#include <util.h>

#include <sys/disklabel.h>

#define SCAN_INCR       4

int
disklabel_scan(struct disklabel *lp, char *buf, size_t buflen)
{
       size_t  i;

       /* scan for the correct magic numbers. */

       for (i=0; i <= buflen - sizeof(*lp); i += SCAN_INCR) {
               memcpy(lp, buf + i, sizeof(*lp));
               if (lp->d_magic == DISKMAGIC && lp->d_magic2 == DISKMAGIC)
                       goto sanity;
       }

       return 1;

sanity:
       /* we've found something, let's sanity check it */
       if (lp->d_npartitions > MAXPARTITIONS || disklabel_dkcksum(lp))
               return 1;

       return 0;
}