sbin/disklabel/dkcksum.c

   1 /*      $NetBSD: dkcksum.c,v 1.12 2009/10/24 18:15:45 tsutsui Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1991, 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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if HAVE_NBTOOL_CONFIG_H
  33 #include "nbtool_config.h"
  34 #endif
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 #if 0
  39 static char sccsid[] = "@(#)dkcksum.c   8.1 (Berkeley) 6/5/93";
  40 #else
  41 __RCSID("$NetBSD: dkcksum.c,v 1.12 2009/10/24 18:15:45 tsutsui Exp $");
  42 #endif
  43 #endif /* not lint */
  44
  45 #include <sys/types.h>
  46 #if HAVE_NBTOOL_CONFIG_H
  47 #include <nbinclude/sys/disklabel.h>
  48 #else
  49 #include <sys/disklabel.h>
  50 #endif /* HAVE_NBTOOL_CONFIG_H */
  51 #include "dkcksum.h"
  52
  53 uint16_t
  54 dkcksum(struct disklabel *lp)
  55 {
  56
  57         return dkcksum_sized(lp, lp->d_npartitions);
  58 }
  59
  60 uint16_t
  61 dkcksum_sized(struct disklabel *lp, size_t npartitions)
  62 {
  63         uint16_t *start, *end;
  64         uint16_t sum;
  65
  66         sum = 0;
  67         start = (uint16_t *)lp;
  68         end = (uint16_t *)&lp->d_partitions[npartitions];
  69         while (start < end)
  70                 sum ^= *start++;
  71         return sum;
  72 }