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
  60extern __u32 secure_ip_id(__be32 daddr);
  61extern u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport);
  62extern u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
  63                                      __be16 dport);
  64extern __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
  65                                        __be16 sport, __be16 dport);
  66extern __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
  67                                          __be16 sport, __be16 dport);
  68extern u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
  69                                       __be16 sport, __be16 dport);
  70
  71#ifndef MODULE
  72extern const struct file_operations random_fops, urandom_fops;
  73#endif
  74
  75unsigned int get_random_int(void);
  76unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
  77
  78u32 random32(void);
  79void srandom32(u32 seed);
  80
  81u32 prandom32(struct rnd_state *);
  82
  83/*
  84 * Handle minimum values for seeds
  85 */
  86static inline u32 __seed(u32 x, u32 m)
  87{
  88        return (x < m) ? x + m : x;
  89}
  90
  91/**
  92 * prandom32_seed - set seed for prandom32().
  93 * @state: pointer to state structure to receive the seed.
  94 * @seed: arbitrary 64-bit value to use as a seed.
  95 */
  96static inline void prandom32_seed(struct rnd_state *state, u64 seed)
  97{
  98        u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
  99
 100        state->s1 = __seed(i, 1);
 101        state->s2 = __seed(i, 7);
 102        state->s3 = __seed(i, 15);
 103}
 104
 105#endif /* __KERNEL___ */
 106
 107#endif /* _LINUX_RANDOM_H */
 108