/*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/

/*

 * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>

 *

 * Permission to use, copy, modify, and 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.

 */

/* OPENBSD ORIGINAL: lib/libc/stdlib/reallocarray.c */

#include <config.h>

#ifndef HAVE_REALLOCARRAY

#undef reallocarray

#include <sys/types.h>

#include <errno.h>

#ifdef HAVE_STDINT_H

#include <stdint.h>

#endif

#include <stdlib.h>

void *reallocarray(void *, size_t, size_t);

/*

 * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX

 * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW

 */

#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))

void *

reallocarray(void *optr, size_t nmemb, size_t size)

{

	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&

	    nmemb > 0 && SIZE_MAX / nmemb < size) {

		errno = ENOMEM;

		return NULL;

	}

	return realloc(optr, size * nmemb);

}

#endif /* HAVE_REALLOCARRAY */