Linux kernel mirror (for testing)
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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 <linux/once.h>
11
12#include <uapi/linux/random.h>
13
14struct random_ready_callback {
15 struct list_head list;
16 void (*func)(struct random_ready_callback *rdy);
17 struct module *owner;
18};
19
20extern void add_device_randomness(const void *, unsigned int);
21extern void add_input_randomness(unsigned int type, unsigned int code,
22 unsigned int value);
23extern void add_interrupt_randomness(int irq, int irq_flags);
24
25extern void get_random_bytes(void *buf, int nbytes);
26extern int add_random_ready_callback(struct random_ready_callback *rdy);
27extern void del_random_ready_callback(struct random_ready_callback *rdy);
28extern void get_random_bytes_arch(void *buf, int nbytes);
29void generate_random_uuid(unsigned char uuid_out[16]);
30extern int random_int_secret_init(void);
31
32#ifndef MODULE
33extern const struct file_operations random_fops, urandom_fops;
34#endif
35
36unsigned int get_random_int(void);
37unsigned long get_random_long(void);
38unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
39
40u32 prandom_u32(void);
41void prandom_bytes(void *buf, size_t nbytes);
42void prandom_seed(u32 seed);
43void prandom_reseed_late(void);
44
45struct rnd_state {
46 __u32 s1, s2, s3, s4;
47};
48
49u32 prandom_u32_state(struct rnd_state *state);
50void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
51void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
52
53#define prandom_init_once(pcpu_state) \
54 DO_ONCE(prandom_seed_full_state, (pcpu_state))
55
56/**
57 * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
58 * @ep_ro: right open interval endpoint
59 *
60 * Returns a pseudo-random number that is in interval [0, ep_ro). Note
61 * that the result depends on PRNG being well distributed in [0, ~0U]
62 * u32 space. Here we use maximally equidistributed combined Tausworthe
63 * generator, that is, prandom_u32(). This is useful when requesting a
64 * random index of an array containing ep_ro elements, for example.
65 *
66 * Returns: pseudo-random number in interval [0, ep_ro)
67 */
68static inline u32 prandom_u32_max(u32 ep_ro)
69{
70 return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
71}
72
73/*
74 * Handle minimum values for seeds
75 */
76static inline u32 __seed(u32 x, u32 m)
77{
78 return (x < m) ? x + m : x;
79}
80
81/**
82 * prandom_seed_state - set seed for prandom_u32_state().
83 * @state: pointer to state structure to receive the seed.
84 * @seed: arbitrary 64-bit value to use as a seed.
85 */
86static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
87{
88 u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
89
90 state->s1 = __seed(i, 2U);
91 state->s2 = __seed(i, 8U);
92 state->s3 = __seed(i, 16U);
93 state->s4 = __seed(i, 128U);
94}
95
96#ifdef CONFIG_ARCH_RANDOM
97# include <asm/archrandom.h>
98#else
99static inline int arch_get_random_long(unsigned long *v)
100{
101 return 0;
102}
103static inline int arch_get_random_int(unsigned int *v)
104{
105 return 0;
106}
107static inline int arch_has_random(void)
108{
109 return 0;
110}
111static inline int arch_get_random_seed_long(unsigned long *v)
112{
113 return 0;
114}
115static inline int arch_get_random_seed_int(unsigned int *v)
116{
117 return 0;
118}
119static inline int arch_has_random_seed(void)
120{
121 return 0;
122}
123#endif
124
125/* Pseudo random number generator from numerical recipes. */
126static inline u32 next_pseudo_random32(u32 seed)
127{
128 return seed * 1664525 + 1013904223;
129}
130
131#endif /* _LINUX_RANDOM_H */