/* safe-alloc.c: safer memory allocation

   Copyright (C) 2009-2019 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify it

   under the terms of the GNU Lesser General Public License as published by the

   Free Software Foundation; either version 2.1 of the License, or 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 Lesser General Public License for more details.

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

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Daniel Berrange <berrange@redhat.com>, 2008 */

#include <config.h>

/* Specification.  */

#include "safe-alloc.h"

#include "xalloc-oversized.h"

#include <stdlib.h>

#include <stddef.h>

#include <errno.h>

/**

 * safe_alloc_alloc_n:

 * @ptrptr: pointer to pointer for address of allocated memory

 * @size: number of bytes to allocate

 * @count: number of elements to allocate

 *

 * Allocate an array of memory 'count' elements long,

 * each with 'size' bytes. Return the address of the

 * allocated memory in 'ptrptr'.  The newly allocated

 * memory is filled with zeros.

 *

 * Return -1 on failure to allocate, zero on success

 */

int

safe_alloc_alloc_n (void *ptrptr, size_t size, size_t count, int zeroed)

{

  if (size == 0 || count == 0)

    {

      *(void **) ptrptr = NULL;

      return 0;

    }

  if (xalloc_oversized (count, size))

    {

      errno = ENOMEM;

      return -1;

    }

  if (zeroed)

    *(void **) ptrptr = calloc (count, size);

  else

    *(void **) ptrptr = malloc (count * size);

  if (*(void **) ptrptr == NULL)

    return -1;

  return 0;

}

/**

 * safe_alloc_realloc_n:

 * @ptrptr: pointer to pointer for address of allocated memory

 * @size: number of bytes to allocate

 * @count: number of elements in array

 *

 * Resize the block of memory in 'ptrptr' to be an array of

 * 'count' elements, each 'size' bytes in length. Update 'ptrptr'

 * with the address of the newly allocated memory. On failure,

 * 'ptrptr' is not changed and still points to the original memory

 * block. The newly allocated memory is filled with zeros.

 *

 * Return -1 on failure to allocate, zero on success

 */

int

safe_alloc_realloc_n (void *ptrptr, size_t size, size_t count)

{

  void *tmp;

  if (size == 0 || count == 0)

    {

      free (*(void **) ptrptr);

      *(void **) ptrptr = NULL;

      return 0;

    }

  if (xalloc_oversized (count, size))

    {

      errno = ENOMEM;

      return -1;

    }

  tmp = realloc (*(void **) ptrptr, size * count);

  if (!tmp)

    return -1;

  *(void **) ptrptr = tmp;

  return 0;

}