xref: /dflybsd-src/contrib/lvm2/dist/lib/misc/crc.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
186d7f5d3SJohn Marino /*	$NetBSD: crc.c,v 1.1.1.1 2008/12/22 00:18:12 haad Exp $	*/
286d7f5d3SJohn Marino 
386d7f5d3SJohn Marino /*
486d7f5d3SJohn Marino  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
586d7f5d3SJohn Marino  * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
686d7f5d3SJohn Marino  *
786d7f5d3SJohn Marino  * This file is part of LVM2.
886d7f5d3SJohn Marino  *
986d7f5d3SJohn Marino  * This copyrighted material is made available to anyone wishing to use,
1086d7f5d3SJohn Marino  * modify, copy, or redistribute it subject to the terms and conditions
1186d7f5d3SJohn Marino  * of the GNU Lesser General Public License v.2.1.
1286d7f5d3SJohn Marino  *
1386d7f5d3SJohn Marino  * You should have received a copy of the GNU Lesser General Public License
1486d7f5d3SJohn Marino  * along with this program; if not, write to the Free Software Foundation,
1586d7f5d3SJohn Marino  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
1686d7f5d3SJohn Marino  */
1786d7f5d3SJohn Marino 
1886d7f5d3SJohn Marino #include "lib.h"
1986d7f5d3SJohn Marino 
2086d7f5d3SJohn Marino #include "crc.h"
2186d7f5d3SJohn Marino 
2286d7f5d3SJohn Marino /* Calculate an endian-independent CRC of supplied buffer */
calc_crc(uint32_t initial,const void * buf,uint32_t size)2386d7f5d3SJohn Marino uint32_t calc_crc(uint32_t initial, const void *buf, uint32_t size)
2486d7f5d3SJohn Marino {
2586d7f5d3SJohn Marino 	static const uint32_t crctab[] = {
2686d7f5d3SJohn Marino 		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
2786d7f5d3SJohn Marino 		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
2886d7f5d3SJohn Marino 		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
2986d7f5d3SJohn Marino 		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
3086d7f5d3SJohn Marino 	};
3186d7f5d3SJohn Marino 	uint32_t i, crc = initial;
3286d7f5d3SJohn Marino 	const uint8_t *data = (const uint8_t *) buf;
3386d7f5d3SJohn Marino 
3486d7f5d3SJohn Marino 	for (i = 0; i < size; i++) {
3586d7f5d3SJohn Marino 		crc ^= *data++;
3686d7f5d3SJohn Marino 		crc = (crc >> 4) ^ crctab[crc & 0xf];
3786d7f5d3SJohn Marino 		crc = (crc >> 4) ^ crctab[crc & 0xf];
3886d7f5d3SJohn Marino 	}
3986d7f5d3SJohn Marino 	return crc;
4086d7f5d3SJohn Marino }
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