forked from osmocom/wireshark
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/*
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* crc6.c
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <glib.h>
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#include "crc6.h"
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guint16 update_crc6_by_bytes(guint16 crc6, guint8 byte1, guint8 byte2) {
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int bit;
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guint32 remainder = ( byte1<<8 | byte2 ) << 6;
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guint32 polynomial = 0x6F << 15;
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for (bit = 15;
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bit >= 0;
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--bit)
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{
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if (remainder & (0x40 << bit))
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{
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remainder ^= polynomial;
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}
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polynomial >>= 1;
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}
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return (guint16)(remainder ^ crc6);
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}
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