1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * Copyright 2023 The FreeBSD Foundation 8 * 9 * Portions of this software was developed by Björn Zeeb 10 * under sponsorship from the FreeBSD Foundation. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice unmodified, this list of conditions, and the following 17 * disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 * $FreeBSD$ 34 */ 35 36 #ifndef _LINUXKPI_LINUX_RANDOM_H_ 37 #define _LINUXKPI_LINUX_RANDOM_H_ 38 39 #include <linux/types.h> 40 #include <sys/random.h> 41 #include <sys/libkern.h> 42 43 static inline void 44 get_random_bytes(void *buf, int nbytes) 45 { 46 47 arc4random_buf(buf, nbytes); 48 } 49 50 static inline u_int 51 get_random_int(void) 52 { 53 u_int val; 54 55 get_random_bytes(&val, sizeof(val)); 56 return (val); 57 } 58 59 #define get_random_u32() get_random_int() 60 61 /* 62 * See "Fast Random Integer Generation in an Interval" by Daniel Lemire 63 * [https://arxiv.org/pdf/1805.10941.pdf] for implementation insights. 64 */ 65 static inline uint32_t 66 get_random_u32_inclusive(uint32_t floor, uint32_t ceil) 67 { 68 uint64_t x; 69 uint32_t t, v; 70 71 MPASS(ceil >= floor); 72 73 v = get_random_u32(); 74 t = ceil - floor + 1; 75 x = (uint64_t)t * v; 76 while (x < t) 77 x = (uint64_t)t * get_random_u32(); 78 v = x >> 32; 79 80 return (floor + v); 81 } 82 83 static inline u_long 84 get_random_long(void) 85 { 86 u_long val; 87 88 get_random_bytes(&val, sizeof(val)); 89 return (val); 90 } 91 92 static __inline uint32_t 93 prandom_u32(void) 94 { 95 uint32_t val; 96 97 get_random_bytes(&val, sizeof(val)); 98 return (val); 99 } 100 101 static inline u32 102 prandom_u32_max(u32 max) 103 { 104 return (arc4random_uniform(max)); 105 } 106 107 #endif /* _LINUXKPI_LINUX_RANDOM_H_ */ 108