1 /* $NetBSD: dkcksum.c,v 1.1 2021/05/17 08:50:36 mrg 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 * from: NetBSD: dkcksum.c,v 1.14 2013/05/03 16:05:12 matt Exp 32 */ 33 34 #include <sys/cdefs.h> 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)dkcksum.c 8.1 (Berkeley) 6/5/93"; 38 #else 39 __RCSID("$NetBSD: dkcksum.c,v 1.1 2021/05/17 08:50:36 mrg Exp $"); 40 #endif 41 #endif /* not lint */ 42 43 #include <sys/types.h> 44 #include <sys/disklabel.h> 45 #include <lib/libkern/libkern.h> 46 47 uint16_t 48 dkcksum(const struct disklabel *lp) 49 { 50 51 return dkcksum_sized(lp, lp->d_npartitions); 52 } 53 54 uint16_t 55 dkcksum_sized(const struct disklabel *lp, size_t npartitions) 56 { 57 const uint16_t *start, *end; 58 uint16_t sum; 59 60 sum = 0; 61 start = (const uint16_t *)lp; 62 end = (const uint16_t *)&lp->d_partitions[npartitions]; 63 while (start < end) { 64 sum ^= *start++; 65 } 66 return sum; 67 } 68