unicorn/qemu/util/guest-random.c

82 lines
1.8 KiB
C

/*
* QEMU guest-visible random functions
*
* Copyright 2019 Linaro, Ltd.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#include "qemu/osdep.h"
#include "qemu/cutils.h"
//#include "qapi/error.h"
#include "qemu/guest-random.h"
#include "crypto/random.h"
//#include "sysemu/replay.h"
#ifndef _MSC_VER
static __thread GRand *thread_rand;
#endif
static bool deterministic = true;
static int glib_random_bytes(void *buf, size_t len)
{
#ifndef _MSC_VER
GRand *rand = thread_rand;
size_t i;
uint32_t x;
if (unlikely(rand == NULL)) {
/* Thread not initialized for a cpu, or main w/o -seed. */
thread_rand = rand = g_rand_new();
}
for (i = 0; i + 4 <= len; i += 4) {
x = g_rand_int(rand);
__builtin_memcpy(buf + i, &x, 4);
}
if (i < len) {
x = g_rand_int(rand);
__builtin_memcpy(buf + i, &x, i - len);
}
#endif
return 0;
}
int qemu_guest_getrandom(void *buf, size_t len)
{
return glib_random_bytes(buf, len);
}
void qemu_guest_getrandom_nofail(void *buf, size_t len)
{
(void)qemu_guest_getrandom(buf, len);
}
uint64_t qemu_guest_random_seed_thread_part1(void)
{
if (deterministic) {
uint64_t ret;
glib_random_bytes(&ret, sizeof(ret));
return ret;
}
return 0;
}
void qemu_guest_random_seed_thread_part2(uint64_t seed)
{
#ifndef _MSC_VER
g_assert(thread_rand == NULL);
if (deterministic) {
thread_rand =
g_rand_new_with_seed_array((const guint32 *)&seed,
sizeof(seed) / sizeof(guint32));
}
#endif
}