/*

 * Copyright (c) 2020 Red Hat, Inc.

 *

 * 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.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA. 

 *

 * $Id: //eng/uds-releases/jasper/src/uds/random.h#2 $

 */

#ifndef RANDOM_H

#define RANDOM_H

#ifdef __KERNEL__

#include <linux/random.h>

#else

#include <stdlib.h>

#endif

#include "compiler.h"

#include "typeDefs.h"

/**

 * Get random unsigned integer in a given range

 *

 * @param lo  Minimum unsigned integer value

 * @param hi  Maximum unsigned integer value

 *

 * @return unsigned integer in the interval [lo,hi]

 **/

unsigned int randomInRange(unsigned int lo, unsigned int hi);

/**

 * Special function wrapper required for compile-time assertions. This

 * function will fail to compile if RAND_MAX is not of the form 2^n - 1.

 **/

void randomCompileTimeAssertions(void);

/**

 * Fill bytes with random data.

 *

 * @param ptr   where to store bytes

 * @param len   number of bytes to write

 **/

#ifdef __KERNEL__

static INLINE void fillRandomly(void *ptr, size_t len)

{

  prandom_bytes(ptr, len);

}

#else

void fillRandomly(void *ptr, size_t len);

#endif

#ifdef __KERNEL__

#define RAND_MAX 2147483647

/**

 * Random number generator

 *

 * @return a random number in the rand 0 to RAND_MAX

 **/

static INLINE long random(void)

{

  long value;

  fillRandomly(&value, sizeof(value));

  return value & RAND_MAX;

}

#endif

#endif /* RANDOM_H */