/*
* Copyright (c) 2009 Lukas Mejdrech
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup net
* @{
*/
/** @file
* General CRC and checksum computation.
*/
#ifndef __NET_CRC_H__
#define __NET_CRC_H__
#include <byteorder.h>
#include <sys/types.h>
/** Computes CRC32 value.
* @param seed Initial value. Often used as 0 or ~0. Input parameter.
* @param data Pointer to the beginning of data to process. Input parameter.
* @param length Length of the data in bits. Input parameter.
* @returns The computed CRC32 of the length bits of the data.
*/
#ifdef ARCH_IS_BIG_ENDIAN
#define compute_crc32( seed, data, length ) compute_crc32_be( seed, ( uint8_t * ) data, length )
#else
#define compute_crc32( seed, data, length ) compute_crc32_le( seed, ( uint8_t * ) data, length )
#endif
/** Computes CRC32 value in the little-endian environment.
* @param seed Initial value. Often used as 0 or ~0. Input parameter.
* @param data Pointer to the beginning of data to process. Input parameter.
* @param length Length of the data in bits. Input parameter.
* @returns The computed CRC32 of the length bits of the data.
*/
uint32_t compute_crc32_le( uint32_t seed, uint8_t * data, size_t length );
/** Computes CRC32 value in the big-endian environment.
* @param seed Initial value. Often used as 0 or ~0. Input parameter.
* @param data Pointer to the beginning of data to process. Input parameter.
* @param length Length of the data in bits. Input parameter.
* @returns The computed CRC32 of the length bits of the data.
*/
uint32_t compute_crc32_be( uint32_t seed, uint8_t * data, size_t length );
/** Computes sum of the 2 byte fields.
* Padds one zero (0) byte if odd.
* @param seed Initial value. Often used as 0 or ~0. Input parameter.
* @param data Pointer to the beginning of data to process. Input parameter.
* @param length Length of the data in bytes. Input parameter.
* @returns The computed checksum of the length bytes of the data.
*/
uint32_t compute_checksum( uint32_t seed, uint8_t * data, size_t length );
/** Compacts the computed checksum to the 16 bit number adding the carries.
* @param sum Computed checksum. Input parameter.
* @returns Compacted computed checksum to the 16 bits.
*/
uint16_t compact_checksum( uint32_t sum );
/** Computes the ip header checksum.
* To compute the checksum of a new packet, the checksum header field must be zero.
* To check the checksum of a received packet, the checksum may be left set.
* The zero (0) value will returned in this case if valid.
* @param data The header data. Input parameter.
* @param length The header length in bytes. Input parameter.
* @returns The internet protocol header checksum.
* @returns 0xFFFF if the computed checksum is zero.
*/
uint16_t ip_checksum( uint8_t * data, size_t length );
#endif
/** @}
*/