LXR qemu/include/qemu/guest-random.h

   1/*
   2 * QEMU guest-visible random functions
   3 *
   4 * Copyright 2019 Linaro, Ltd.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License as published by the Free
   8 * Software Foundation; either version 2 of the License, or (at your option)
   9 * any later version.
  10 */
  11
  12#ifndef QEMU_GUEST_RANDOM_H
  13#define QEMU_GUEST_RANDOM_H
  14
  15/**
  16 * qemu_guest_random_seed_main(const char *optarg, Error **errp)
  17 * @optarg: a non-NULL pointer to a C string
  18 * @errp: an error indicator
  19 *
  20 * The @optarg value is that which accompanies the -seed argument.
  21 * This forces qemu_guest_getrandom into deterministic mode.
  22 *
  23 * Returns 0 on success, < 0 on failure while setting *errp.
  24 */
  25int qemu_guest_random_seed_main(const char *optarg, Error **errp);
  26
  27/**
  28 * qemu_guest_random_seed_thread_part1(void)
  29 *
  30 * If qemu_getrandom is in deterministic mode, returns an
  31 * independent seed for the new thread.  Otherwise returns 0.
  32 */
  33uint64_t qemu_guest_random_seed_thread_part1(void);
  34
  35/**
  36 * qemu_guest_random_seed_thread_part2(uint64_t seed)
  37 * @seed: a value for the new thread.
  38 *
  39 * If qemu_guest_getrandom is in deterministic mode, this stores an
  40 * independent seed for the new thread.  Otherwise a no-op.
  41 */
  42void qemu_guest_random_seed_thread_part2(uint64_t seed);
  43
  44/**
  45 * qemu_guest_getrandom(void *buf, size_t len, Error **errp)
  46 * @buf: a buffer of bytes to be written
  47 * @len: the number of bytes in @buf
  48 * @errp: an error indicator
  49 *
  50 * Fills len bytes in buf with random data.  This should only be used
  51 * for data presented to the guest.  Host-side crypto services should
  52 * use qcrypto_random_bytes.
  53 *
  54 * Returns 0 on success, < 0 on failure while setting *errp.
  55 */
  56int qemu_guest_getrandom(void *buf, size_t len, Error **errp);
  57
  58/**
  59 * qemu_guest_getrandom_nofail(void *buf, size_t len)
  60 * @buf: a buffer of bytes to be written
  61 * @len: the number of bytes in @buf
  62 *
  63 * Like qemu_guest_getrandom, but will assert for failure.
  64 * Use this when there is no reasonable recovery.
  65 */
  66void qemu_guest_getrandom_nofail(void *buf, size_t len);
  67
  68#endif /* QEMU_GUEST_RANDOM_H */
  69