From 4132d40e50c576ae6cf9e03e4f552ea091035626 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stig=20Bj=C3=B8rlykke?= Date: Tue, 30 Aug 2011 13:46:42 +0000 Subject: Move all crc routines to libwsutil. This way we can use the crc routines in wiretap. svn path=/trunk/; revision=38800 --- wsutil/crc16.h | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 wsutil/crc16.h (limited to 'wsutil/crc16.h') diff --git a/wsutil/crc16.h b/wsutil/crc16.h new file mode 100644 index 0000000000..0fb0548dc4 --- /dev/null +++ b/wsutil/crc16.h @@ -0,0 +1,126 @@ +/* crc16.h + * Declaration of CRC-16 routines and table + * + * 2004 Richard van der Hoff + * + * $Id$ + * + * Wireshark - Network traffic analyzer + * By Gerald Combs + * Copyright 1998 Gerald Combs + * + * Copied from README.developer + * + * 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. +*/ + +#ifndef __CRC16_H_ +#define __CRC16_H_ + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Calculate the CCITT/ITU/CRC-16 16-bit CRC + + (parameters for this CRC are: + Polynomial: x^16 + x^12 + x^5 + 1 (0x1021); + Start value 0xFFFF; + XOR result with 0xFFFF; + First bit is LSB) +*/ + +/** Compute CRC16 CCITT checksum of a buffer of data. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 CCITT checksum. */ +extern guint16 crc16_ccitt(const guint8 *buf, guint len); + +/** Compute CRC16 X.25 CCITT checksum of a buffer of data. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 X.25 CCITT checksum. */ +extern guint16 crc16_x25_ccitt(const guint8 *buf, guint len); + +/** Compute CRC16 CCITT checksum of a buffer of data. If computing the + * checksum over multiple buffers and you want to feed the partial CRC16 + * back in, remember to take the 1's complement of the partial CRC16 first. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @param seed The seed to use. + @return The CRC16 CCITT checksum (using the given seed). */ +extern guint16 crc16_ccitt_seed(const guint8 *buf, guint len, guint16 seed); + +/** Compute CRC16 CCITT checksum of a tv buffer. + @param tvb The tv buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 CCITT checksum. */ +extern guint16 crc16_ccitt_tvb(tvbuff_t *tvb, guint len); + +/** Compute CRC16 X.25 CCITT checksum of a tv buffer. + @param tvb The tv buffer containing the data. + @param len The number of bytes to include in the computation. + @return The CRC16 X.25 CCITT checksum. */ +extern guint16 crc16_x25_ccitt_tvb(tvbuff_t *tvb, guint len); + +/** Compute CRC16 CCITT checksum of a tv buffer. + @param tvb The tv buffer containing the data. + @param offset The offset into the tv buffer. + @param len The number of bytes to include in the computation. + @return The CRC16 CCITT checksum. */ +extern guint16 crc16_ccitt_tvb_offset(tvbuff_t *tvb, guint offset, guint len); + +/** Compute CRC16 CCITT checksum of a tv buffer. If computing the + * checksum over multiple tv buffers and you want to feed the partial CRC16 + * back in, remember to take the 1's complement of the partial CRC16 first. + @param tvb The tv buffer containing the data. + @param len The number of bytes to include in the computation. + @param seed The seed to use. + @return The CRC16 CCITT checksum (using the given seed). */ +extern guint16 crc16_ccitt_tvb_seed(tvbuff_t *tvb, guint len, guint16 seed); + +/** Compute CRC16 CCITT checksum of a tv buffer. If computing the + * checksum over multiple tv buffers and you want to feed the partial CRC16 + * back in, remember to take the 1's complement of the partial CRC16 first. + @param tvb The tv buffer containing the data. + @param offset The offset into the tv buffer. + @param len The number of bytes to include in the computation. + @param seed The seed to use. + @return The CRC16 CCITT checksum (using the given seed). */ +extern guint16 crc16_ccitt_tvb_offset_seed(tvbuff_t *tvb, guint offset, + guint len, guint16 seed); + +/** Compute the "plain" CRC16 checksum of a tv buffer using the following + * parameters: + * Width = 16 + * Poly = 0x8005 + * XorIn = 0x0000 + * ReflectIn = True + * XorOut = 0x0000 + * ReflectOut = True + * Algorithm = table-driven + * Direct = True + @param tvb The tv buffer containing the data. + @param offset The offset into the tv buffer. + @param len The number of bytes to include in the computation. + @return The CRC16 checksum. */ +extern guint16 crc16_plain_tvb_offset(tvbuff_t *tvb, guint offset, guint len); + + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* crc16.h */ -- cgit v1.2.1