1 bfdc637c 2020-09-20 stsp /*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
 2 bfdc637c 2020-09-20 stsp /*
 3 bfdc637c 2020-09-20 stsp  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
 4 bfdc637c 2020-09-20 stsp  *
 5 bfdc637c 2020-09-20 stsp  * Permission to use, copy, modify, and distribute this software for any
 6 bfdc637c 2020-09-20 stsp  * purpose with or without fee is hereby granted, provided that the above
 7 bfdc637c 2020-09-20 stsp  * copyright notice and this permission notice appear in all copies.
 8 bfdc637c 2020-09-20 stsp  *
 9 bfdc637c 2020-09-20 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 bfdc637c 2020-09-20 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 bfdc637c 2020-09-20 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 bfdc637c 2020-09-20 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 bfdc637c 2020-09-20 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 bfdc637c 2020-09-20 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 bfdc637c 2020-09-20 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 bfdc637c 2020-09-20 stsp  */
17 bfdc637c 2020-09-20 stsp 
18 bfdc637c 2020-09-20 stsp #include <sys/types.h>
19 bfdc637c 2020-09-20 stsp #include <errno.h>
20 bfdc637c 2020-09-20 stsp #include <stdint.h>
21 bfdc637c 2020-09-20 stsp #include <stdlib.h>
22 bfdc637c 2020-09-20 stsp 
23 bfdc637c 2020-09-20 stsp /*
24 bfdc637c 2020-09-20 stsp  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
25 bfdc637c 2020-09-20 stsp  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
26 bfdc637c 2020-09-20 stsp  */
27 bfdc637c 2020-09-20 stsp #define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
28 bfdc637c 2020-09-20 stsp 
29 bfdc637c 2020-09-20 stsp void *
30 bfdc637c 2020-09-20 stsp reallocarray(void *optr, size_t nmemb, size_t size)
31 bfdc637c 2020-09-20 stsp {
32 bfdc637c 2020-09-20 stsp 	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
33 bfdc637c 2020-09-20 stsp 	    nmemb > 0 && SIZE_MAX / nmemb < size) {
34 bfdc637c 2020-09-20 stsp 		errno = ENOMEM;
35 bfdc637c 2020-09-20 stsp 		return NULL;
36 bfdc637c 2020-09-20 stsp 	}
37 bfdc637c 2020-09-20 stsp 	return realloc(optr, size * nmemb);
38 bfdc637c 2020-09-20 stsp }