1287915Sdes/*	$OpenBSD: reallocarray.c,v 1.1 2014/05/08 21:43:49 deraadt Exp $	*/
2287915Sdes/*
3287915Sdes * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
4287915Sdes *
5287915Sdes * Permission to use, copy, modify, and distribute this software for any
6287915Sdes * purpose with or without fee is hereby granted, provided that the above
7287915Sdes * copyright notice and this permission notice appear in all copies.
8287915Sdes *
9287915Sdes * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10287915Sdes * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11287915Sdes * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12287915Sdes * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13287915Sdes * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14287915Sdes * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15287915Sdes * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16287915Sdes */
17287915Sdes
18287915Sdes#include "config.h"
19287915Sdes#include <sys/types.h>
20287915Sdes#include <errno.h>
21294190Sdes#ifdef HAVE_STDINT_H
22287915Sdes#include <stdint.h>
23294190Sdes#endif
24294190Sdes#include <limits.h>
25287915Sdes#include <stdlib.h>
26287915Sdes
27287915Sdes/*
28287915Sdes * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
29287915Sdes * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
30287915Sdes */
31287915Sdes#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
32287915Sdes
33287915Sdesvoid *
34287915Sdesreallocarray(void *optr, size_t nmemb, size_t size)
35287915Sdes{
36287915Sdes	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
37287915Sdes	    nmemb > 0 && SIZE_MAX / nmemb < size) {
38287915Sdes		errno = ENOMEM;
39287915Sdes		return NULL;
40287915Sdes	}
41287915Sdes	return realloc(optr, size * nmemb);
42287915Sdes}
43