105 lines
3.8 KiB
C
105 lines
3.8 KiB
C
/* crc16.h
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* Declaration of CRC-16 routines and table
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*
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* 2004 Richard van der Hoff <richardv@mxtelecom.com>
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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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef __CRC16_H__
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#define __CRC16_H__
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#include "ws_symbol_export.h"
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#ifdef __cplusplus
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extern "C" {
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#endif /* __cplusplus */
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/* Calculate the CCITT/ITU/CRC-16 16-bit CRC
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(parameters for this CRC are:
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Polynomial: x^16 + x^12 + x^5 + 1 (0x1021);
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Start value 0xFFFF;
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XOR result with 0xFFFF;
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First bit is LSB)
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*/
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/** Compute CRC16 CCITT checksum of a buffer of data.
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@param buf The buffer containing the data.
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@param len The number of bytes to include in the computation.
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@return The CRC16 CCITT checksum. */
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WS_DLL_PUBLIC guint16 crc16_ccitt(const guint8 *buf, guint len);
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/** Compute CRC16 X.25 CCITT checksum of a buffer of data.
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@param buf The buffer containing the data.
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@param len The number of bytes to include in the computation.
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@return The CRC16 X.25 CCITT checksum. */
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WS_DLL_PUBLIC guint16 crc16_x25_ccitt_seed(const guint8 *buf, guint len, guint16 seed);
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/** Compute CRC16 CCITT checksum of a buffer of data. If computing the
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* checksum over multiple buffers and you want to feed the partial CRC16
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* back in, remember to take the 1's complement of the partial CRC16 first.
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@param buf The buffer containing the data.
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@param len The number of bytes to include in the computation.
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@param seed The seed to use.
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@return The CRC16 CCITT checksum (using the given seed). */
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WS_DLL_PUBLIC guint16 crc16_ccitt_seed(const guint8 *buf, guint len, guint16 seed);
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/** Calculates a CRC16 checksum for the given buffer with the polynom
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* 0x5935 using a precompiled CRC table
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* @param buf a pointer to a buffer of the given length
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* @param len the length of the given buffer
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* @param seed The seed to use.
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* @return the CRC16 checksum for the buffer
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*/
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WS_DLL_PUBLIC guint16 crc16_0x5935(const guint8 *buf, guint32 len, guint16 seed);
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/** Calculates a CRC16 checksum for the given buffer with the polynom
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* 0x755B using a precompiled CRC table
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* @param buf a pointer to a buffer of the given length
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* @param len the length of the given buffer
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* @param seed The seed to use.
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* @return the CRC16 checksum for the buffer
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*/
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WS_DLL_PUBLIC guint16 crc16_0x755B(const guint8 *buf, guint32 len, guint16 seed);
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/** Computes CRC16 checksum for the given data with the polynom 0x9949 using
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* precompiled CRC table
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* @param buf a pointer to a buffer of the given length
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* @param len the length of the given buffer
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* @param seed The seed to use.
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* @return the CRC16 checksum for the buffer
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*/
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WS_DLL_PUBLIC guint16 crc16_0x9949_seed(const guint8 *buf, guint len, guint16 seed);
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/** Computes CRC16 checksum for the given data with the polynom 0x3D65 using
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* precompiled CRC table
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* @param buf a pointer to a buffer of the given length
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* @param len the length of the given buffer
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* @param seed The seed to use.
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* @return the CRC16 checksum for the buffer
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*/
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WS_DLL_PUBLIC guint16 crc16_0x3D65_seed(const guint8 *buf, guint len, guint16 seed);
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#ifdef __cplusplus
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}
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#endif /* __cplusplus */
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#endif /* crc16.h */
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