/*
 * 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.c#2 $
 */

#include "random.h"

#include "permassert.h"

/*****************************************************************************/
unsigned int randomInRange(unsigned int lo, unsigned int hi)
{
  return lo + random() % (hi - lo + 1);
}

/*****************************************************************************/
void randomCompileTimeAssertions(void)
{
  STATIC_ASSERT((((uint64_t) RAND_MAX + 1) & RAND_MAX) == 0);
}

#ifndef __KERNEL__
/*****************************************************************************/
void fillRandomly(void *ptr, size_t len)
{
  uint64_t randNum  = 0;
  uint64_t randMask = 0;
  const uint64_t multiplier = (uint64_t) RAND_MAX + 1;

  byte *bp = ptr;
  for (size_t i = 0; i < len; ++i) {
    if (randMask < 0xff) {
      randNum  = randNum * multiplier + random();
      randMask = randMask * multiplier + RAND_MAX;
    }
    bp[i] = randNum & 0xff;
    randNum >>= 8;
    randMask >>= 8;
  }
}
#endif