1/*
2 * Copyright (c) 2010-2013 Apple Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24#include <stdlib.h>
25#include <string.h>
26#include "secure.h"
27
28char *
29__stpncpy_chk (char *restrict dest, char *restrict src,
30	       size_t len, size_t dstlen)
31{
32  size_t n;
33  char *retval;
34
35  if (__builtin_expect (dstlen < len, 0))
36    __chk_fail_overflow ();
37
38  retval = stpncpy (dest, src, len); // Normally returns a pointer to the \0
39  n = retval - dest + 1;
40
41  // Check if it's pointing to the location after the buffer after not writing \0
42  if (n == len + 1)
43    n--;
44
45  if (__builtin_expect (__chk_assert_no_overlap != 0, 1))
46    __chk_overlap(dest, n, src, n);
47
48  return retval;
49}
50