summaryrefslogtreecommitdiffstats
path: root/kernel/include/linux/random.h
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/include/linux/random.h')
-rw-r--r--kernel/include/linux/random.h115
1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/include/linux/random.h b/kernel/include/linux/random.h
new file mode 100644
index 000000000..4a64ad52d
--- /dev/null
+++ b/kernel/include/linux/random.h
@@ -0,0 +1,115 @@
+/*
+ * include/linux/random.h
+ *
+ * Include file for the random number generator.
+ */
+#ifndef _LINUX_RANDOM_H
+#define _LINUX_RANDOM_H
+
+#include <uapi/linux/random.h>
+
+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, __u64 ip);
+
+extern void get_random_bytes(void *buf, int nbytes);
+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 */