1*d500c338Sflorian /* 2*d500c338Sflorian * util/rfc_1982.h - RFC 1982 Serial Number Arithmetic 3*d500c338Sflorian * 4*d500c338Sflorian * Copyright (c) 2023, NLnet Labs. All rights reserved. 5*d500c338Sflorian * 6*d500c338Sflorian * This software is open source. 7*d500c338Sflorian * 8*d500c338Sflorian * Redistribution and use in source and binary forms, with or without 9*d500c338Sflorian * modification, are permitted provided that the following conditions 10*d500c338Sflorian * are met: 11*d500c338Sflorian * 12*d500c338Sflorian * Redistributions of source code must retain the above copyright notice, 13*d500c338Sflorian * this list of conditions and the following disclaimer. 14*d500c338Sflorian * 15*d500c338Sflorian * Redistributions in binary form must reproduce the above copyright notice, 16*d500c338Sflorian * this list of conditions and the following disclaimer in the documentation 17*d500c338Sflorian * and/or other materials provided with the distribution. 18*d500c338Sflorian * 19*d500c338Sflorian * Neither the name of the NLNET LABS nor the names of its contributors may 20*d500c338Sflorian * be used to endorse or promote products derived from this software without 21*d500c338Sflorian * specific prior written permission. 22*d500c338Sflorian * 23*d500c338Sflorian * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24*d500c338Sflorian * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25*d500c338Sflorian * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26*d500c338Sflorian * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27*d500c338Sflorian * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28*d500c338Sflorian * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29*d500c338Sflorian * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30*d500c338Sflorian * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31*d500c338Sflorian * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32*d500c338Sflorian * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33*d500c338Sflorian * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34*d500c338Sflorian */ 35*d500c338Sflorian 36*d500c338Sflorian /** 37*d500c338Sflorian * \file 38*d500c338Sflorian * 39*d500c338Sflorian * This file contains functions for RFC 1982 serial number arithmetic. 40*d500c338Sflorian */ 41*d500c338Sflorian #ifndef RFC_1982_H 42*d500c338Sflorian #define RFC_1982_H 43*d500c338Sflorian 44*d500c338Sflorian /** 45*d500c338Sflorian * RFC 1982 comparison, uses unsigned integers, and tries to avoid 46*d500c338Sflorian * compiler optimization (eg. by avoiding a-b<0 comparisons). 47*d500c338Sflorian * @param a: value to compare. 48*d500c338Sflorian * @param b: value to compare. 49*d500c338Sflorian * @return 0 if equal, 1 if a > b, else -1. 50*d500c338Sflorian */ 51*d500c338Sflorian int compare_1982(uint32_t a, uint32_t b); 52*d500c338Sflorian 53*d500c338Sflorian /** 54*d500c338Sflorian * RFC 1982 subtraction, uses unsigned integers, and tries to avoid 55*d500c338Sflorian * compiler optimization (eg. by avoiding a-b<0 comparisons). 56*d500c338Sflorian * @param a: value to subtract from. 57*d500c338Sflorian * @param b: value to subtract. 58*d500c338Sflorian * @return the difference between them if we know that b is larger than a, 59*d500c338Sflorian * that is the distance between them in serial number arithmetic. 60*d500c338Sflorian */ 61*d500c338Sflorian uint32_t subtract_1982(uint32_t a, uint32_t b); 62*d500c338Sflorian 63*d500c338Sflorian #endif /* RFC_1982_H */ 64