Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * include/linux/random.h | |
3 | * | |
4 | * Include file for the random number generator. | |
5 | */ | |
1da177e4 LT |
6 | #ifndef _LINUX_RANDOM_H |
7 | #define _LINUX_RANDOM_H | |
8 | ||
607ca46e | 9 | #include <uapi/linux/random.h> |
1da177e4 | 10 | |
a2080a67 | 11 | extern void add_device_randomness(const void *, unsigned int); |
1da177e4 LT |
12 | extern void add_input_randomness(unsigned int type, unsigned int code, |
13 | unsigned int value); | |
775f4b29 | 14 | extern void add_interrupt_randomness(int irq, int irq_flags); |
1da177e4 LT |
15 | |
16 | extern void get_random_bytes(void *buf, int nbytes); | |
16b369a9 | 17 | extern void get_blocking_random_bytes(void *buf, int nbytes); |
c2557a30 | 18 | extern void get_random_bytes_arch(void *buf, int nbytes); |
1da177e4 | 19 | void generate_random_uuid(unsigned char uuid_out[16]); |
47d06e53 | 20 | extern int random_int_secret_init(void); |
1da177e4 | 21 | |
1da177e4 | 22 | #ifndef MODULE |
54047320 | 23 | extern const struct file_operations random_fops, urandom_fops; |
1da177e4 LT |
24 | #endif |
25 | ||
26 | unsigned int get_random_int(void); | |
27 | unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len); | |
28 | ||
496f2f93 | 29 | u32 prandom_u32(void); |
a98406e2 | 30 | void prandom_bytes(void *buf, size_t nbytes); |
496f2f93 | 31 | void prandom_seed(u32 seed); |
4af712e8 | 32 | void prandom_reseed_late(void); |
aaa248f6 | 33 | |
38e9efcd | 34 | struct rnd_state { |
a98814ce | 35 | __u32 s1, s2, s3, s4; |
38e9efcd DB |
36 | }; |
37 | ||
a98814ce | 38 | u32 prandom_u32_state(struct rnd_state *state); |
a98406e2 | 39 | void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); |
5960164f | 40 | |
f337db64 DB |
41 | /** |
42 | * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro) | |
43 | * @ep_ro: right open interval endpoint | |
44 | * | |
45 | * Returns a pseudo-random number that is in interval [0, ep_ro). Note | |
46 | * that the result depends on PRNG being well distributed in [0, ~0U] | |
47 | * u32 space. Here we use maximally equidistributed combined Tausworthe | |
48 | * generator, that is, prandom_u32(). This is useful when requesting a | |
49 | * random index of an array containing ep_ro elements, for example. | |
50 | * | |
51 | * Returns: pseudo-random number in interval [0, ep_ro) | |
52 | */ | |
53 | static inline u32 prandom_u32_max(u32 ep_ro) | |
54 | { | |
55 | return (u32)(((u64) prandom_u32() * ep_ro) >> 32); | |
56 | } | |
57 | ||
5960164f JE |
58 | /* |
59 | * Handle minimum values for seeds | |
60 | */ | |
61 | static inline u32 __seed(u32 x, u32 m) | |
62 | { | |
63 | return (x < m) ? x + m : x; | |
64 | } | |
65 | ||
66 | /** | |
496f2f93 | 67 | * prandom_seed_state - set seed for prandom_u32_state(). |
5960164f JE |
68 | * @state: pointer to state structure to receive the seed. |
69 | * @seed: arbitrary 64-bit value to use as a seed. | |
70 | */ | |
496f2f93 | 71 | static inline void prandom_seed_state(struct rnd_state *state, u64 seed) |
5960164f JE |
72 | { |
73 | u32 i = (seed >> 32) ^ (seed << 10) ^ seed; | |
74 | ||
a98814ce DB |
75 | state->s1 = __seed(i, 2U); |
76 | state->s2 = __seed(i, 8U); | |
77 | state->s3 = __seed(i, 16U); | |
78 | state->s4 = __seed(i, 128U); | |
5960164f JE |
79 | } |
80 | ||
63d77173 PA |
81 | #ifdef CONFIG_ARCH_RANDOM |
82 | # include <asm/archrandom.h> | |
83 | #else | |
84 | static inline int arch_get_random_long(unsigned long *v) | |
85 | { | |
86 | return 0; | |
87 | } | |
88 | static inline int arch_get_random_int(unsigned int *v) | |
89 | { | |
90 | return 0; | |
91 | } | |
7b878d4b PA |
92 | static inline int arch_has_random(void) |
93 | { | |
94 | return 0; | |
95 | } | |
d20f78d2 PA |
96 | static inline int arch_get_random_seed_long(unsigned long *v) |
97 | { | |
98 | return 0; | |
99 | } | |
100 | static inline int arch_get_random_seed_int(unsigned int *v) | |
101 | { | |
102 | return 0; | |
103 | } | |
7b878d4b PA |
104 | static inline int arch_has_random_seed(void) |
105 | { | |
106 | return 0; | |
107 | } | |
63d77173 PA |
108 | #endif |
109 | ||
055dc21a TH |
110 | /* Pseudo random number generator from numerical recipes. */ |
111 | static inline u32 next_pseudo_random32(u32 seed) | |
112 | { | |
113 | return seed * 1664525 + 1013904223; | |
114 | } | |
115 | ||
1da177e4 | 116 | #endif /* _LINUX_RANDOM_H */ |