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