[linux-2.6-block.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 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);
205a525c HX	24	extern int add_random_ready_callback(struct random_ready_callback *rdy);
205a525c HX	25	extern void del_random_ready_callback(struct random_ready_callback *rdy);
c2557a30	26	extern void get_random_bytes_arch(void *buf, int nbytes);
1da177e4	27	void generate_random_uuid(unsigned char uuid_out[16]);
47d06e53	28	extern int random_int_secret_init(void);
1da177e4	29
1da177e4	30	#ifndef MODULE
54047320	31	extern const struct file_operations random_fops, urandom_fops;
1da177e4 LT	32	#endif
	33
	34	unsigned int get_random_int(void);
	35	unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
	36
496f2f93	37	u32 prandom_u32(void);
a98406e2	38	void prandom_bytes(void *buf, size_t nbytes);
496f2f93	39	void prandom_seed(u32 seed);
4af712e8	40	void prandom_reseed_late(void);
aaa248f6	41
38e9efcd	42	struct rnd_state {
a98814ce	43	__u32 s1, s2, s3, s4;
38e9efcd DB	44	};
38e9efcd DB	45
a98814ce	46	u32 prandom_u32_state(struct rnd_state *state);
a98406e2	47	void prandom_bytes_state(struct rnd_state state, void buf, size_t nbytes);
5960164f	48
f337db64 DB	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	*/
	61	static inline u32 prandom_u32_max(u32 ep_ro)
	62	{
	63	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
	64	}
	65
5960164f JE	66	/*
	67	* Handle minimum values for seeds
	68	*/
	69	static inline u32 __seed(u32 x, u32 m)
	70	{
	71	return (x < m) ? x + m : x;
	72	}
	73
	74	/**
496f2f93	75	* prandom_seed_state - set seed for prandom_u32_state().
5960164f JE	76	* @state: pointer to state structure to receive the seed.
	77	* @seed: arbitrary 64-bit value to use as a seed.
	78	*/
496f2f93	79	static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
5960164f JE	80	{
	81	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
	82
a98814ce DB	83	state->s1 = __seed(i, 2U);
	84	state->s2 = __seed(i, 8U);
	85	state->s3 = __seed(i, 16U);
	86	state->s4 = __seed(i, 128U);
5960164f JE	87	}
5960164f JE	88
63d77173 PA	89	#ifdef CONFIG_ARCH_RANDOM
	90	# include <asm/archrandom.h>
	91	#else
	92	static inline int arch_get_random_long(unsigned long *v)
	93	{
	94	return 0;
	95	}
	96	static inline int arch_get_random_int(unsigned int *v)
	97	{
	98	return 0;
	99	}
7b878d4b PA	100	static inline int arch_has_random(void)
	101	{
	102	return 0;
	103	}
d20f78d2 PA	104	static inline int arch_get_random_seed_long(unsigned long *v)
	105	{
	106	return 0;
	107	}
	108	static inline int arch_get_random_seed_int(unsigned int *v)
	109	{
	110	return 0;
	111	}
7b878d4b PA	112	static inline int arch_has_random_seed(void)
	113	{
	114	return 0;
	115	}
63d77173 PA	116	#endif
63d77173 PA	117
055dc21a TH	118	/* Pseudo random number generator from numerical recipes. */
	119	static inline u32 next_pseudo_random32(u32 seed)
	120	{
	121	return seed * 1664525 + 1013904223;
	122	}
	123
1da177e4	124	#endif /* _LINUX_RANDOM_H */