Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * include/linux/random.h
3 *
4 * Include file for the random number generator.
5 */
6#ifndef _LINUX_RANDOM_H
7#define _LINUX_RANDOM_H
8
9#include <linux/list.h>
10#include <uapi/linux/random.h>
11
12struct random_ready_callback {
13 struct list_head list;
14 void (*func)(struct random_ready_callback *rdy);
15 struct module *owner;
16};
17
18extern void add_device_randomness(const void *, unsigned int);
19extern void add_input_randomness(unsigned int type, unsigned int code,
20 unsigned int value);
21extern void add_interrupt_randomness(int irq, int irq_flags);
22
23extern void get_random_bytes(void *buf, int nbytes);
24extern int add_random_ready_callback(struct random_ready_callback *rdy);
25extern void del_random_ready_callback(struct random_ready_callback *rdy);
26extern void get_random_bytes_arch(void *buf, int nbytes);
27void generate_random_uuid(unsigned char uuid_out[16]);
28extern int random_int_secret_init(void);
29
30#ifndef MODULE
31extern const struct file_operations random_fops, urandom_fops;
32#endif
33
34unsigned int get_random_int(void);
35unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
36
37u32 prandom_u32(void);
38void prandom_bytes(void *buf, size_t nbytes);
39void prandom_seed(u32 seed);
40void prandom_reseed_late(void);
41
42struct rnd_state {
43 __u32 s1, s2, s3, s4;
44};
45
46u32 prandom_u32_state(struct rnd_state *state);
47void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
48
49/**
50 * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
51 * @ep_ro: right open interval endpoint
52 *
53 * Returns a pseudo-random number that is in interval [0, ep_ro). Note
54 * that the result depends on PRNG being well distributed in [0, ~0U]
55 * u32 space. Here we use maximally equidistributed combined Tausworthe
56 * generator, that is, prandom_u32(). This is useful when requesting a
57 * random index of an array containing ep_ro elements, for example.
58 *
59 * Returns: pseudo-random number in interval [0, ep_ro)
60 */
61static inline u32 prandom_u32_max(u32 ep_ro)
62{
63 return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
64}
65
66/*
67 * Handle minimum values for seeds
68 */
69static inline u32 __seed(u32 x, u32 m)
70{
71 return (x < m) ? x + m : x;
72}
73
74/**
75 * prandom_seed_state - set seed for prandom_u32_state().
76 * @state: pointer to state structure to receive the seed.
77 * @seed: arbitrary 64-bit value to use as a seed.
78 */
79static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
80{
81 u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
82
83 state->s1 = __seed(i, 2U);
84 state->s2 = __seed(i, 8U);
85 state->s3 = __seed(i, 16U);
86 state->s4 = __seed(i, 128U);
87}
88
89#ifdef CONFIG_ARCH_RANDOM
90# include <asm/archrandom.h>
91#else
92static inline int arch_get_random_long(unsigned long *v)
93{
94 return 0;
95}
96static inline int arch_get_random_int(unsigned int *v)
97{
98 return 0;
99}
100static inline int arch_has_random(void)
101{
102 return 0;
103}
104static inline int arch_get_random_seed_long(unsigned long *v)
105{
106 return 0;
107}
108static inline int arch_get_random_seed_int(unsigned int *v)
109{
110 return 0;
111}
112static inline int arch_has_random_seed(void)
113{
114 return 0;
115}
116#endif
117
118/* Pseudo random number generator from numerical recipes. */
119static inline u32 next_pseudo_random32(u32 seed)
120{
121 return seed * 1664525 + 1013904223;
122}
123
124#endif /* _LINUX_RANDOM_H */