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dkcksum.c revision 1.1 
      1  1.1  mrg /*	$NetBSD: dkcksum.c,v 1.1 2021/05/17 08:50:36 mrg Exp $	*/
      2  1.1  mrg 
      3  1.1  mrg /*-
      4  1.1  mrg  * Copyright (c) 1991, 1993
      5  1.1  mrg  *	The Regents of the University of California.  All rights reserved.
      6  1.1  mrg  *
      7  1.1  mrg  * Redistribution and use in source and binary forms, with or without
      8  1.1  mrg  * modification, are permitted provided that the following conditions
      9  1.1  mrg  * are met:
     10  1.1  mrg  * 1. Redistributions of source code must retain the above copyright
     11  1.1  mrg  *    notice, this list of conditions and the following disclaimer.
     12  1.1  mrg  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.1  mrg  *    notice, this list of conditions and the following disclaimer in the
     14  1.1  mrg  *    documentation and/or other materials provided with the distribution.
     15  1.1  mrg  * 3. Neither the name of the University nor the names of its contributors
     16  1.1  mrg  *    may be used to endorse or promote products derived from this software
     17  1.1  mrg  *    without specific prior written permission.
     18  1.1  mrg  *
     19  1.1  mrg  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  1.1  mrg  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  1.1  mrg  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  1.1  mrg  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  1.1  mrg  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  1.1  mrg  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  1.1  mrg  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  1.1  mrg  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  1.1  mrg  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  1.1  mrg  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  1.1  mrg  * SUCH DAMAGE.
     30  1.1  mrg  *
     31  1.1  mrg  * from: NetBSD: dkcksum.c,v 1.14 2013/05/03 16:05:12 matt Exp
     32  1.1  mrg  */
     33  1.1  mrg 
     34  1.1  mrg #include <sys/cdefs.h>
     35  1.1  mrg #ifndef lint
     36  1.1  mrg #if 0
     37  1.1  mrg static char sccsid[] = "@(#)dkcksum.c	8.1 (Berkeley) 6/5/93";
     38  1.1  mrg #else
     39  1.1  mrg __RCSID("$NetBSD: dkcksum.c,v 1.1 2021/05/17 08:50:36 mrg Exp $");
     40  1.1  mrg #endif
     41  1.1  mrg #endif /* not lint */
     42  1.1  mrg 
     43  1.1  mrg #include <sys/types.h>
     44  1.1  mrg #include <sys/disklabel.h>
     45  1.1  mrg #include <lib/libkern/libkern.h>
     46  1.1  mrg 
     47  1.1  mrg uint16_t
     48  1.1  mrg dkcksum(const struct disklabel *lp)
     49  1.1  mrg {
     50  1.1  mrg 
     51  1.1  mrg 	return dkcksum_sized(lp, lp->d_npartitions);
     52  1.1  mrg }
     53  1.1  mrg 
     54  1.1  mrg uint16_t
     55  1.1  mrg dkcksum_sized(const struct disklabel *lp, size_t npartitions)
     56  1.1  mrg {
     57  1.1  mrg 	const uint16_t *start, *end;
     58  1.1  mrg 	uint16_t sum;
     59  1.1  mrg 
     60  1.1  mrg 	sum = 0;
     61  1.1  mrg 	start = (const uint16_t *)lp;
     62  1.1  mrg 	end = (const uint16_t *)&lp->d_partitions[npartitions];
     63  1.1  mrg 	while (start < end) {
     64  1.1  mrg 		sum ^= *start++;
     65  1.1  mrg 	}
     66  1.1  mrg 	return sum;
     67  1.1  mrg }
     68