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/*
* Copyright (c) 2008, 2009 Nicira Networks.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include "random.h"
#include <errno.h>
#include <stdlib.h>
#include <sys/time.h>
#include "util.h"
void
random_init(void)
{
static bool inited = false;
if (!inited) {
struct timeval tv;
inited = true;
if (gettimeofday(&tv, NULL) < 0) {
ovs_fatal(errno, "gettimeofday");
}
srand(tv.tv_sec ^ tv.tv_usec);
}
}
void
random_bytes(void *p_, size_t n)
{
uint8_t *p = p_;
random_init();
while (n--) {
*p++ = rand();
}
}
uint8_t
random_uint8(void)
{
random_init();
return rand();
}
uint16_t
random_uint16(void)
{
if (RAND_MAX >= UINT16_MAX) {
random_init();
return rand();
} else {
uint16_t x;
random_bytes(&x, sizeof x);
return x;
}
}
uint32_t
random_uint32(void)
{
if (RAND_MAX >= UINT32_MAX) {
random_init();
return rand();
} else if (RAND_MAX == INT32_MAX) {
random_init();
return rand() | ((rand() & 1u) << 31);
} else {
uint32_t x;
random_bytes(&x, sizeof x);
return x;
}
}
int
random_range(int max)
{
return random_uint32() % max;
}
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