1 /* $NetBSD: random.h,v 1.4 2021/12/19 11:49:12 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _LINUX_RANDOM_H_ 33 #define _LINUX_RANDOM_H_ 34 35 #include <sys/cprng.h> 36 37 static inline int 38 get_random_int(void) 39 { 40 int v; 41 42 cprng_strong(kern_cprng, &v, sizeof v, 0); 43 44 return v; 45 } 46 47 static inline long 48 get_random_long(void) 49 { 50 long v; 51 52 cprng_strong(kern_cprng, &v, sizeof v, 0); 53 54 return v; 55 } 56 57 static inline uint32_t 58 get_random_u32(void) 59 { 60 uint32_t v; 61 62 cprng_strong(kern_cprng, &v, sizeof v, 0); 63 64 return v; 65 } 66 67 static inline uint32_t 68 prandom_u32_max(uint32_t bound) 69 { 70 uint32_t v, min; 71 72 min = (-bound) % bound; 73 do { 74 v = get_random_u32(); 75 } while (v < min); 76 77 return v % bound; 78 } 79 80 #endif /* _LINUX_RANDOM_H_ */ 81