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
  37 struct rand_pool_info {
  38         int     entropy_count;
  39         int     buf_size;
  40         __u32   buf[0];
  41 };
  42
  43 struct rnd_state {
  44         __u32 s1, s2, s3;
  45 };
  46
  47 /* Exported functions */
  48
  49 #ifdef __KERNEL__
  50
  51 extern void rand_initialize_irq(int irq);
  52
  53 extern void add_input_randomness(unsigned int type, unsigned int code,
  54                                  unsigned int value);
  55 extern void add_interrupt_randomness(int irq);
  56
  57 extern void get_random_bytes(void *buf, int nbytes);
  58 void generate_random_uuid(unsigned char uuid_out[16]);
  59
  60 #ifndef MODULE
  61 extern const struct file_operations random_fops, urandom_fops;
  62 #endif
  63
  64 unsigned int get_random_int(void);
  65 unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
  66
  67 u32 random32(void);
  68 void srandom32(u32 seed);
  69
  70 u32 prandom32(struct rnd_state *);
  71
  72 /*
  73  * Handle minimum values for seeds
  74  */
  75 static 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  */
  85 static 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 */