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
get_random_int(void)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
get_random_long(void)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
get_random_u32(void)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
prandom_u32_max(uint32_t bound)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