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Diffstat (limited to 'wsutil/crc32.h')
-rw-r--r-- | wsutil/crc32.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/wsutil/crc32.h b/wsutil/crc32.h new file mode 100644 index 0000000000..90d77ae31f --- /dev/null +++ b/wsutil/crc32.h @@ -0,0 +1,76 @@ +/* crc32.h + * Declaration of CRC-32 routine and table + * + * $Id$ + * + * 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. + */ + +#ifndef __CRC32_H__ +#define __CRC32_H__ + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +#define CRC32_CCITT_SEED 0xFFFFFFFF +#define CRC32C_PRELOAD 0xffffffff + +/* + * Byte swap fix contributed by Dave Wysochanski <davidw@netapp.com>. + */ +#define CRC32C_SWAP(crc32c_value) \ + (((crc32c_value & 0xff000000) >> 24) | \ + ((crc32c_value & 0x00ff0000) >> 8) | \ + ((crc32c_value & 0x0000ff00) << 8) | \ + ((crc32c_value & 0x000000ff) << 24)) + +#define CRC32C(c,d) (c=(c>>8)^crc32c_table[(c^(d))&0xFF]) + +extern const guint32 crc32c_table[256]; + +/** Compute CRC32C checksum of a buffer of data. + @param buf The buffer containing the data. + @param len The number of bytes to include in the computation. + @param crc The preload value for the CRC32C computation. + @return The CRC32C checksum. */ +extern guint32 crc32c_calculate(const void *buf, int len, guint32 crc); + +extern const guint32 crc32_ccitt_table[256]; + +/** Compute CRC32 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 CRC32 CCITT checksum. */ +extern guint32 crc32_ccitt(const guint8 *buf, guint len); + +/** Compute CRC32 CCITT checksum of a buffer of data. If computing the + * checksum over multiple buffers and you want to feed the partial CRC32 + * back in, remember to take the 1's complement of the partial CRC32 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 CRC32 CCITT checksum (using the given seed). */ +extern guint32 crc32_ccitt_seed(const guint8 *buf, guint len, guint32 seed); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* crc32.h */ |