LXR linux/include/linux/random.h

   1/*
   2 * include/linux/random.h
   3 *
   4 * Include file for the random number generator.
   5 */
   6
   7#ifndef _LINUX_RANDOM_H
   8#define _LINUX_RANDOM_H
   9
  10#include <linux/types.h>
  11#include <linux/ioctl.h>
  12#include <linux/irqnr.h>
  13
  14/* ioctl()'s for the random number generator */
  15
  16/* Get the entropy count. */
  17#define RNDGETENTCNT    _IOR( 'R', 0x00, int )
  18
  19/* Add to (or subtract from) the entropy count.  (Superuser only.) */
  20#define RNDADDTOENTCNT  _IOW( 'R', 0x01, int )
  21
  22/* Get the contents of the entropy pool.  (Superuser only.) */
  23#define RNDGETPOOL      _IOR( 'R', 0x02, int [2] )
  24
  25/* 
  26 * Write bytes into the entropy pool and add to the entropy count.
  27 * (Superuser only.)
  28 */
  29#define RNDADDENTROPY   _IOW( 'R', 0x03, int [2] )
  30
  31/* Clear entropy count to 0.  (Superuser only.) */
  32#define RNDZAPENTCNT    _IO( 'R', 0x04 )
  33
  34/* Clear the entropy pool and associated counters.  (Superuser only.) */
  35#define RNDCLEARPOOL    _IO( 'R', 0x06 )
  36
  37struct rand_pool_info {
  38        int     entropy_count;
  39        int     buf_size;
  40        __u32   buf[0];
  41};
  42
  43struct rnd_state {
  44        __u32 s1, s2, s3;
  45};
  46
  47/* Exported functions */
  48
  49#ifdef __KERNEL__
  50
  51extern void rand_initialize_irq(int irq);
  52
  53extern void add_input_randomness(unsigned int type, unsigned int code,
  54                                 unsigned int value);
  55extern void add_interrupt_randomness(int irq);
  56
  57extern void get_random_bytes(void *buf, int nbytes);
  58void generate_random_uuid(unsigned char uuid_out[16]);
  59
  60#ifndef MODULE
  61extern const struct file_operations random_fops, urandom_fops;
  62#endif
  63
  64unsigned int get_random_int(void);
  65unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
  66
  67u32 random32(void);
  68void srandom32(u32 seed);
  69
  70u32 prandom32(struct rnd_state *);
  71
  72/*
  73 * Handle minimum values for seeds
  74 */
  75static inline u32 __seed(u32 x, u32 m)
  76{
  77        return (x < m) ? x + m : x;
  78}
  79
  80/**
  81 * prandom32_seed - set seed for prandom32().
  82 * @state: pointer to state structure to receive the seed.
  83 * @seed: arbitrary 64-bit value to use as a seed.
  84 */
  85static inline void prandom32_seed(struct rnd_state *state, u64 seed)
  86{
  87        u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
  88
  89        state->s1 = __seed(i, 1);
  90        state->s2 = __seed(i, 7);
  91        state->s3 = __seed(i, 15);
  92}
  93
  94#endif /* __KERNEL___ */
  95
  96#endif /* _LINUX_RANDOM_H */
  97