1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * include/linux/random.h
4 *
5 * Include file for the random number generator.
6 */
7
8#ifndef _LINUX_RANDOM_H
9#define _LINUX_RANDOM_H
10
11#include <linux/types.h>
12#include <linux/ioctl.h>
13#include <linux/irqnr.h>
14
15/* ioctl()'s for the random number generator */
16
17/* Get the entropy count. */
18#define RNDGETENTCNT _IOR( 'R', 0x00, int )
19
20/* Add to (or subtract from) the entropy count. (Superuser only.) */
21#define RNDADDTOENTCNT _IOW( 'R', 0x01, int )
22
23/* Get the contents of the entropy pool. (Superuser only.) */
24#define RNDGETPOOL _IOR( 'R', 0x02, int [2] )
25
26/*
27 * Write bytes into the entropy pool and add to the entropy count.
28 * (Superuser only.)
29 */
30#define RNDADDENTROPY _IOW( 'R', 0x03, int [2] )
31
32/* Clear entropy count to 0. (Superuser only.) */
33#define RNDZAPENTCNT _IO( 'R', 0x04 )
34
35/* Clear the entropy pool and associated counters. (Superuser only.) */
36#define RNDCLEARPOOL _IO( 'R', 0x06 )
37
38/* Reseed CRNG. (Superuser only.) */
39#define RNDRESEEDCRNG _IO( 'R', 0x07 )
40
41struct rand_pool_info {
42 int entropy_count;
43 int buf_size;
44 __u32 buf[0];
45};
46
47/*
48 * Flags for getrandom(2)
49 *
50 * GRND_NONBLOCK Don't block and return EAGAIN instead
51 * GRND_RANDOM No effect
52 * GRND_INSECURE Return non-cryptographic random bytes
53 */
54#define GRND_NONBLOCK 0x0001
55#define GRND_RANDOM 0x0002
56#define GRND_INSECURE 0x0004
57
58#endif /* _LINUX_RANDOM_H */
59