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