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/*
* util/rfc_1982.h - RFC 1982 Serial Number Arithmetic
*
* Copyright (c) 2023, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* 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.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT
* HOLDER OR CONTRIBUTORS 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.
*/
/**
* \file
*
* This file contains functions for RFC 1982 serial number arithmetic.
*/
#ifndef RFC_1982_H
#define RFC_1982_H
/**
* RFC 1982 comparison, uses unsigned integers, and tries to avoid
* compiler optimization (eg. by avoiding a-b<0 comparisons).
* @param a: value to compare.
* @param b: value to compare.
* @return 0 if equal, 1 if a > b, else -1.
*/
int compare_1982(uint32_t a, uint32_t b);
/**
* RFC 1982 subtraction, uses unsigned integers, and tries to avoid
* compiler optimization (eg. by avoiding a-b<0 comparisons).
* @param a: value to subtract from.
* @param b: value to subtract.
* @return the difference between them if we know that b is larger than a,
* that is the distance between them in serial number arithmetic.
*/
uint32_t subtract_1982(uint32_t a, uint32_t b);
#endif /* RFC_1982_H */
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