[deliverable/linux.git] / include / linux / random.h

/*
 * include/linux/random.h
 *
 * Include file for the random number generator.
 */
#ifndef _LINUX_RANDOM_H
#define _LINUX_RANDOM_H

#include <linux/list.h>
#include <uapi/linux/random.h>

struct random_ready_callback {
	struct list_head list;
	void (*func)(struct random_ready_callback *rdy);
	struct module *owner;
};

extern void add_device_randomness(const void *, unsigned int);
extern void add_input_randomness(unsigned int type, unsigned int code,
				 unsigned int value);
extern void add_interrupt_randomness(int irq, int irq_flags);

extern void get_random_bytes(void *buf, int nbytes);
extern void get_blocking_random_bytes(void *buf, int nbytes);
extern int add_random_ready_callback(struct random_ready_callback *rdy);
extern void del_random_ready_callback(struct random_ready_callback *rdy);
extern void get_random_bytes_arch(void *buf, int nbytes);
void generate_random_uuid(unsigned char uuid_out[16]);
extern int random_int_secret_init(void);

#ifndef MODULE
extern const struct file_operations random_fops, urandom_fops;
#endif

unsigned int get_random_int(void);
unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);

u32 prandom_u32(void);
void prandom_bytes(void *buf, size_t nbytes);
void prandom_seed(u32 seed);
void prandom_reseed_late(void);

struct rnd_state {
	__u32 s1, s2, s3, s4;
};

u32 prandom_u32_state(struct rnd_state *state);
void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);

/**
 * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
 * @ep_ro: right open interval endpoint
 *
 * Returns a pseudo-random number that is in interval [0, ep_ro). Note
 * that the result depends on PRNG being well distributed in [0, ~0U]
 * u32 space. Here we use maximally equidistributed combined Tausworthe
 * generator, that is, prandom_u32(). This is useful when requesting a
 * random index of an array containing ep_ro elements, for example.
 *
 * Returns: pseudo-random number in interval [0, ep_ro)
 */
static inline u32 prandom_u32_max(u32 ep_ro)
{
	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
}

/*
 * Handle minimum values for seeds
 */
static inline u32 __seed(u32 x, u32 m)
{
	return (x < m) ? x + m : x;
}

/**
 * prandom_seed_state - set seed for prandom_u32_state().
 * @state: pointer to state structure to receive the seed.
 * @seed: arbitrary 64-bit value to use as a seed.
 */
static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
{
	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;

	state->s1 = __seed(i,   2U);
	state->s2 = __seed(i,   8U);
	state->s3 = __seed(i,  16U);
	state->s4 = __seed(i, 128U);
}

#ifdef CONFIG_ARCH_RANDOM
# include <asm/archrandom.h>
#else
static inline int arch_get_random_long(unsigned long *v)
{
	return 0;
}
static inline int arch_get_random_int(unsigned int *v)
{
	return 0;
}
static inline int arch_has_random(void)
{
	return 0;
}
static inline int arch_get_random_seed_long(unsigned long *v)
{
	return 0;
}
static inline int arch_get_random_seed_int(unsigned int *v)
{
	return 0;
}
static inline int arch_has_random_seed(void)
{
	return 0;
}
#endif

/* Pseudo random number generator from numerical recipes. */
static inline u32 next_pseudo_random32(u32 seed)
{
	return seed * 1664525 + 1013904223;
}

#endif /* _LINUX_RANDOM_H */
Commit	Line	Data
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
205a525c	9	#include <linux/list.h>
607ca46e	10	#include <uapi/linux/random.h>
1da177e4	11
205a525c HX	12	struct random_ready_callback {
	13	struct list_head list;
	14	void (func)(struct random_ready_callback rdy);
	15	struct module *owner;
	16	};
	17
a2080a67	18	extern void add_device_randomness(const void *, unsigned int);
1da177e4 LT	19	extern void add_input_randomness(unsigned int type, unsigned int code,
1da177e4 LT	20	unsigned int value);
775f4b29	21	extern void add_interrupt_randomness(int irq, int irq_flags);
1da177e4 LT	22
1da177e4 LT	23	extern void get_random_bytes(void *buf, int nbytes);
16b369a9	24	extern void get_blocking_random_bytes(void *buf, int nbytes);
205a525c HX	25	extern int add_random_ready_callback(struct random_ready_callback *rdy);
205a525c HX	26	extern void del_random_ready_callback(struct random_ready_callback *rdy);
c2557a30	27	extern void get_random_bytes_arch(void *buf, int nbytes);
1da177e4	28	void generate_random_uuid(unsigned char uuid_out[16]);
47d06e53	29	extern int random_int_secret_init(void);
1da177e4	30
1da177e4	31	#ifndef MODULE
54047320	32	extern const struct file_operations random_fops, urandom_fops;
1da177e4 LT	33	#endif
	34
	35	unsigned int get_random_int(void);
	36	unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
	37
496f2f93	38	u32 prandom_u32(void);
a98406e2	39	void prandom_bytes(void *buf, size_t nbytes);
496f2f93	40	void prandom_seed(u32 seed);
4af712e8	41	void prandom_reseed_late(void);
aaa248f6	42
38e9efcd	43	struct rnd_state {
a98814ce	44	__u32 s1, s2, s3, s4;
38e9efcd DB	45	};
38e9efcd DB	46
a98814ce	47	u32 prandom_u32_state(struct rnd_state *state);
a98406e2	48	void prandom_bytes_state(struct rnd_state state, void buf, size_t nbytes);
5960164f	49
f337db64 DB	50	/**
	51	* prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
	52	* @ep_ro: right open interval endpoint
	53	*
	54	* Returns a pseudo-random number that is in interval [0, ep_ro). Note
	55	* that the result depends on PRNG being well distributed in [0, ~0U]
	56	* u32 space. Here we use maximally equidistributed combined Tausworthe
	57	* generator, that is, prandom_u32(). This is useful when requesting a
	58	* random index of an array containing ep_ro elements, for example.
	59	*
	60	* Returns: pseudo-random number in interval [0, ep_ro)
	61	*/
	62	static inline u32 prandom_u32_max(u32 ep_ro)
	63	{
	64	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
	65	}
	66
5960164f JE	67	/*
	68	* Handle minimum values for seeds
	69	*/
	70	static inline u32 __seed(u32 x, u32 m)
	71	{
	72	return (x < m) ? x + m : x;
	73	}
	74
	75	/**
496f2f93	76	* prandom_seed_state - set seed for prandom_u32_state().
5960164f JE	77	* @state: pointer to state structure to receive the seed.
	78	* @seed: arbitrary 64-bit value to use as a seed.
	79	*/
496f2f93	80	static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
5960164f JE	81	{
	82	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
	83
a98814ce DB	84	state->s1 = __seed(i, 2U);
	85	state->s2 = __seed(i, 8U);
	86	state->s3 = __seed(i, 16U);
	87	state->s4 = __seed(i, 128U);
5960164f JE	88	}
5960164f JE	89
63d77173 PA	90	#ifdef CONFIG_ARCH_RANDOM
	91	# include <asm/archrandom.h>
	92	#else
	93	static inline int arch_get_random_long(unsigned long *v)
	94	{
	95	return 0;
	96	}
	97	static inline int arch_get_random_int(unsigned int *v)
	98	{
	99	return 0;
	100	}
7b878d4b PA	101	static inline int arch_has_random(void)
	102	{
	103	return 0;
	104	}
d20f78d2 PA	105	static inline int arch_get_random_seed_long(unsigned long *v)
	106	{
	107	return 0;
	108	}
	109	static inline int arch_get_random_seed_int(unsigned int *v)
	110	{
	111	return 0;
	112	}
7b878d4b PA	113	static inline int arch_has_random_seed(void)
	114	{
	115	return 0;
	116	}
63d77173 PA	117	#endif
63d77173 PA	118
055dc21a TH	119	/* Pseudo random number generator from numerical recipes. */
	120	static inline u32 next_pseudo_random32(u32 seed)
	121	{
	122	return seed * 1664525 + 1013904223;
	123	}
	124
1da177e4	125	#endif /* _LINUX_RANDOM_H */