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/*
* Copyright (c) 2008, 2009 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#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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