| 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 | |
| 14 | struct random_ready_callback { |
| 15 | struct list_head list; |
| 16 | void (*func)(struct random_ready_callback *rdy); |
| 17 | struct module *owner; |
| 18 | }; |
| 19 | |
| 20 | extern void add_device_randomness(const void *, unsigned int); |
| 21 | |
| 22 | #if defined(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) && !defined(__CHECKER__) |
| 23 | static inline void add_latent_entropy(void) |
| 24 | { |
| 25 | add_device_randomness((const void *)&latent_entropy, |
| 26 | sizeof(latent_entropy)); |
| 27 | } |
| 28 | #else |
| 29 | static inline void add_latent_entropy(void) {} |
| 30 | #endif |
| 31 | |
| 32 | extern void add_input_randomness(unsigned int type, unsigned int code, |
| 33 | unsigned int value) __latent_entropy; |
| 34 | extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; |
| 35 | |
| 36 | extern void get_random_bytes(void *buf, int nbytes); |
| 37 | extern int add_random_ready_callback(struct random_ready_callback *rdy); |
| 38 | extern void del_random_ready_callback(struct random_ready_callback *rdy); |
| 39 | extern void get_random_bytes_arch(void *buf, int nbytes); |
| 40 | extern int random_int_secret_init(void); |
| 41 | |
| 42 | #ifndef MODULE |
| 43 | extern const struct file_operations random_fops, urandom_fops; |
| 44 | #endif |
| 45 | |
| 46 | unsigned int get_random_int(void); |
| 47 | unsigned long get_random_long(void); |
| 48 | unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len); |
| 49 | |
| 50 | u32 prandom_u32(void); |
| 51 | void prandom_bytes(void *buf, size_t nbytes); |
| 52 | void prandom_seed(u32 seed); |
| 53 | void prandom_reseed_late(void); |
| 54 | |
| 55 | struct rnd_state { |
| 56 | __u32 s1, s2, s3, s4; |
| 57 | }; |
| 58 | |
| 59 | u32 prandom_u32_state(struct rnd_state *state); |
| 60 | void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); |
| 61 | void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); |
| 62 | |
| 63 | #define prandom_init_once(pcpu_state) \ |
| 64 | DO_ONCE(prandom_seed_full_state, (pcpu_state)) |
| 65 | |
| 66 | /** |
| 67 | * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro) |
| 68 | * @ep_ro: right open interval endpoint |
| 69 | * |
| 70 | * Returns a pseudo-random number that is in interval [0, ep_ro). Note |
| 71 | * that the result depends on PRNG being well distributed in [0, ~0U] |
| 72 | * u32 space. Here we use maximally equidistributed combined Tausworthe |
| 73 | * generator, that is, prandom_u32(). This is useful when requesting a |
| 74 | * random index of an array containing ep_ro elements, for example. |
| 75 | * |
| 76 | * Returns: pseudo-random number in interval [0, ep_ro) |
| 77 | */ |
| 78 | static inline u32 prandom_u32_max(u32 ep_ro) |
| 79 | { |
| 80 | return (u32)(((u64) prandom_u32() * ep_ro) >> 32); |
| 81 | } |
| 82 | |
| 83 | /* |
| 84 | * Handle minimum values for seeds |
| 85 | */ |
| 86 | static inline u32 __seed(u32 x, u32 m) |
| 87 | { |
| 88 | return (x < m) ? x + m : x; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * prandom_seed_state - set seed for prandom_u32_state(). |
| 93 | * @state: pointer to state structure to receive the seed. |
| 94 | * @seed: arbitrary 64-bit value to use as a seed. |
| 95 | */ |
| 96 | static inline void prandom_seed_state(struct rnd_state *state, u64 seed) |
| 97 | { |
| 98 | u32 i = (seed >> 32) ^ (seed << 10) ^ seed; |
| 99 | |
| 100 | state->s1 = __seed(i, 2U); |
| 101 | state->s2 = __seed(i, 8U); |
| 102 | state->s3 = __seed(i, 16U); |
| 103 | state->s4 = __seed(i, 128U); |
| 104 | } |
| 105 | |
| 106 | #ifdef CONFIG_ARCH_RANDOM |
| 107 | # include <asm/archrandom.h> |
| 108 | #else |
| 109 | static inline bool arch_get_random_long(unsigned long *v) |
| 110 | { |
| 111 | return 0; |
| 112 | } |
| 113 | static inline bool arch_get_random_int(unsigned int *v) |
| 114 | { |
| 115 | return 0; |
| 116 | } |
| 117 | static inline bool arch_has_random(void) |
| 118 | { |
| 119 | return 0; |
| 120 | } |
| 121 | static inline bool arch_get_random_seed_long(unsigned long *v) |
| 122 | { |
| 123 | return 0; |
| 124 | } |
| 125 | static inline bool arch_get_random_seed_int(unsigned int *v) |
| 126 | { |
| 127 | return 0; |
| 128 | } |
| 129 | static inline bool arch_has_random_seed(void) |
| 130 | { |
| 131 | return 0; |
| 132 | } |
| 133 | #endif |
| 134 | |
| 135 | /* Pseudo random number generator from numerical recipes. */ |
| 136 | static inline u32 next_pseudo_random32(u32 seed) |
| 137 | { |
| 138 | return seed * 1664525 + 1013904223; |
| 139 | } |
| 140 | |
| 141 | #endif /* _LINUX_RANDOM_H */ |