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 34 #ifndef _LINUXKPI_LINUX_RANDOM_H_ 35 #define _LINUXKPI_LINUX_RANDOM_H_ 36 37 #include <linux/types.h> 38 #include <sys/random.h> 39 #include <sys/libkern.h> 40 41 static inline void 42 get_random_bytes(void *buf, int nbytes) 43 { 44 45 arc4random_buf(buf, nbytes); 46 } 47 48 static inline u_int 49 get_random_int(void) 50 { 51 u_int val; 52 53 get_random_bytes(&val, sizeof(val)); 54 return (val); 55 } 56 57 static inline uint8_t 58 get_random_u8(void) 59 { 60 uint8_t val; 61 62 get_random_bytes(&val, sizeof(val)); 63 return (val); 64 } 65 66 #define get_random_u32() get_random_int() 67 68 /* 69 * See "Fast Random Integer Generation in an Interval" by Daniel Lemire 70 * [https://arxiv.org/pdf/1805.10941.pdf] for implementation insights. 71 */ 72 static inline uint32_t 73 get_random_u32_inclusive(uint32_t floor, uint32_t ceil) 74 { 75 uint64_t x; 76 uint32_t t, v; 77 78 MPASS(ceil >= floor); 79 80 v = get_random_u32(); 81 t = ceil - floor + 1; 82 x = (uint64_t)t * v; 83 while (x < t) 84 x = (uint64_t)t * get_random_u32(); 85 v = x >> 32; 86 87 return (floor + v); 88 } 89 90 static inline u_long 91 get_random_long(void) 92 { 93 u_long val; 94 95 get_random_bytes(&val, sizeof(val)); 96 return (val); 97 } 98 99 static inline uint64_t 100 get_random_u64(void) 101 { 102 uint64_t val; 103 104 get_random_bytes(&val, sizeof(val)); 105 return (val); 106 } 107 108 static inline uint32_t 109 get_random_u32_below(uint32_t max) 110 { 111 return (arc4random_uniform(max)); 112 } 113 114 static __inline uint32_t 115 prandom_u32(void) 116 { 117 uint32_t val; 118 119 get_random_bytes(&val, sizeof(val)); 120 return (val); 121 } 122 123 static inline u32 124 prandom_u32_max(u32 max) 125 { 126 return (arc4random_uniform(max)); 127 } 128 129 #endif /* _LINUXKPI_LINUX_RANDOM_H_ */ 130