1*56a34939Shaad /* $NetBSD: crc.c,v 1.1.1.1 2008/12/22 00:18:12 haad Exp $ */
2*56a34939Shaad
3*56a34939Shaad /*
4*56a34939Shaad * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
5*56a34939Shaad * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
6*56a34939Shaad *
7*56a34939Shaad * This file is part of LVM2.
8*56a34939Shaad *
9*56a34939Shaad * This copyrighted material is made available to anyone wishing to use,
10*56a34939Shaad * modify, copy, or redistribute it subject to the terms and conditions
11*56a34939Shaad * of the GNU Lesser General Public License v.2.1.
12*56a34939Shaad *
13*56a34939Shaad * You should have received a copy of the GNU Lesser General Public License
14*56a34939Shaad * along with this program; if not, write to the Free Software Foundation,
15*56a34939Shaad * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16*56a34939Shaad */
17*56a34939Shaad
18*56a34939Shaad #include "lib.h"
19*56a34939Shaad
20*56a34939Shaad #include "crc.h"
21*56a34939Shaad
22*56a34939Shaad /* Calculate an endian-independent CRC of supplied buffer */
calc_crc(uint32_t initial,const void * buf,uint32_t size)23*56a34939Shaad uint32_t calc_crc(uint32_t initial, const void *buf, uint32_t size)
24*56a34939Shaad {
25*56a34939Shaad static const uint32_t crctab[] = {
26*56a34939Shaad 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
27*56a34939Shaad 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
28*56a34939Shaad 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
29*56a34939Shaad 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
30*56a34939Shaad };
31*56a34939Shaad uint32_t i, crc = initial;
32*56a34939Shaad const uint8_t *data = (const uint8_t *) buf;
33*56a34939Shaad
34*56a34939Shaad for (i = 0; i < size; i++) {
35*56a34939Shaad crc ^= *data++;
36*56a34939Shaad crc = (crc >> 4) ^ crctab[crc & 0xf];
37*56a34939Shaad crc = (crc >> 4) ^ crctab[crc & 0xf];
38*56a34939Shaad }
39*56a34939Shaad return crc;
40*56a34939Shaad }
41