1 /* $NetBSD: dkcksum.c,v 1.14 2013/05/03 16:05:12 matt 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 1.14 2013/05/03 16:05:12 matt 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
dkcksum(const struct disklabel * lp)54 dkcksum(const struct disklabel *lp)
55 {
56
57 return dkcksum_sized(lp, lp->d_npartitions);
58 }
59
60 uint16_t
dkcksum_sized(const struct disklabel * lp,size_t npartitions)61 dkcksum_sized(const struct disklabel *lp, size_t npartitions)
62 {
63 const uint16_t *start, *end;
64 uint16_t sum;
65
66 sum = 0;
67 start = (const uint16_t *)lp;
68 end = (const uint16_t *)&lp->d_partitions[npartitions];
69 while (start < end) {
70 sum ^= *start++;
71 }
72 return sum;
73 }
74