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Diffstat (limited to 'wsutil/crc8.c')
-rw-r--r-- | wsutil/crc8.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/wsutil/crc8.c b/wsutil/crc8.c new file mode 100644 index 0000000000..ceeb53fd1b --- /dev/null +++ b/wsutil/crc8.c @@ -0,0 +1,102 @@ +/* crc8.c + * Implementation CRC-8 declarations and routines + * + * 2011 Roland Knall <rknall@gmail.com> + * + * $Id$ + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <glib.h> +#include <wsutil/crc8.h> + +/* @brief Precompiled table for CRC8 values for the polynom 0x2F */ +static const guint8 crc8_precompiled_2F[256] = +{ + 0x00, 0x2F, 0x5E, 0x71, 0xBC, 0x93, 0xE2, 0xCD, + 0x57, 0x78, 0x09, 0x26, 0xEB, 0xC4, 0xB5, 0x9A, + 0xAE, 0x81, 0xF0, 0xDF, 0x12, 0x3D, 0x4C, 0x63, + 0xF9, 0xD6, 0xA7, 0x88, 0x45, 0x6A, 0x1B, 0x34, + 0x73, 0x5C, 0x2D, 0x02, 0xCF, 0xE0, 0x91, 0xBE, + 0x24, 0x0B, 0x7A, 0x55, 0x98, 0xB7, 0xC6, 0xE9, + 0xDD, 0xF2, 0x83, 0xAC, 0x61, 0x4E, 0x3F, 0x10, + 0x8A, 0xA5, 0xD4, 0xFB, 0x36, 0x19, 0x68, 0x47, + 0xE6, 0xC9, 0xB8, 0x97, 0x5A, 0x75, 0x04, 0x2B, + 0xB1, 0x9E, 0xEF, 0xC0, 0x0D, 0x22, 0x53, 0x7C, + 0x48, 0x67, 0x16, 0x39, 0xF4, 0xDB, 0xAA, 0x85, + 0x1F, 0x30, 0x41, 0x6E, 0xA3, 0x8C, 0xFD, 0xD2, + 0x95, 0xBA, 0xCB, 0xE4, 0x29, 0x06, 0x77, 0x58, + 0xC2, 0xED, 0x9C, 0xB3, 0x7E, 0x51, 0x20, 0x0F, + 0x3B, 0x14, 0x65, 0x4A, 0x87, 0xA8, 0xD9, 0xF6, + 0x6C, 0x43, 0x32, 0x1D, 0xD0, 0xFF, 0x8E, 0xA1, + 0xE3, 0xCC, 0xBD, 0x92, 0x5F, 0x70, 0x01, 0x2E, + 0xB4, 0x9B, 0xEA, 0xC5, 0x08, 0x27, 0x56, 0x79, + 0x4D, 0x62, 0x13, 0x3C, 0xF1, 0xDE, 0xAF, 0x80, + 0x1A, 0x35, 0x44, 0x6B, 0xA6, 0x89, 0xF8, 0xD7, + 0x90, 0xBF, 0xCE, 0xE1, 0x2C, 0x03, 0x72, 0x5D, + 0xC7, 0xE8, 0x99, 0xB6, 0x7B, 0x54, 0x25, 0x0A, + 0x3E, 0x11, 0x60, 0x4F, 0x82, 0xAD, 0xDC, 0xF3, + 0x69, 0x46, 0x37, 0x18, 0xD5, 0xFA, 0x8B, 0xA4, + 0x05, 0x2A, 0x5B, 0x74, 0xB9, 0x96, 0xE7, 0xC8, + 0x52, 0x7D, 0x0C, 0x23, 0xEE, 0xC1, 0xB0, 0x9F, + 0xAB, 0x84, 0xF5, 0xDA, 0x17, 0x38, 0x49, 0x66, + 0xFC, 0xD3, 0xA2, 0x8D, 0x40, 0x6F, 0x1E, 0x31, + 0x76, 0x59, 0x28, 0x07, 0xCA, 0xE5, 0x94, 0xBB, + 0x21, 0x0E, 0x7F, 0x50, 0x9D, 0xB2, 0xC3, 0xEC, + 0xD8, 0xF7, 0x86, 0xA9, 0x64, 0x4B, 0x3A, 0x15, + 0x8F, 0xA0, 0xD1, 0xFE, 0x33, 0x1C, 0x6D, 0x42 +}; + + +/** Calculates a CRC8 checksum for the given buffer with the polynom + * stored in the crc_table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @param crc_table a table storing 256 entries for crc8 checksums + * @return the CRC8 checksum for the buffer + */ +static guint8 crc8_precompiled(guint8 *buf, guint32 len, guint8 seed, const guint8 crc_table[]) +{ + guint8 crc; + + crc = seed; + while(len-- > 0) + crc = crc_table[(guint8)(*buf++) ^ crc]; + + return crc; +} + +/** Calculates a CRC8 checksum for the given buffer with the polynom + * 0x2F using the precompiled CRC table + * @param buf a pointer to a buffer of the given length + * @param len the length of the given buffer + * @param seed The seed to use. + * @return the CRC8 checksum for the buffer + */ +guint8 crc8_0x2F(guint8 *buf, guint32 len, guint8 seed) +{ + return crc8_precompiled(buf, len, seed, crc8_precompiled_2F); +} |