1/* Copyright (C) 2005-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <limits.h>
19#include <stdlib.h>
20#include <string.h>
21#include <unistd.h>
22
23
24char *
25__realpath_chk (const char *buf, char *resolved, size_t resolvedlen)
26{
27#ifdef PATH_MAX
28 if (resolvedlen < PATH_MAX)
29 __chk_fail ();
30
31 return __realpath (buf, resolved);
32#else
33 long int pathmax =__pathconf (buf, _PC_PATH_MAX);
34 if (pathmax != -1)
35 {
36 /* We do have a fixed limit. */
37 if (resolvedlen < pathmax)
38 __chk_fail ();
39
40 return __realpath (buf, resolved);
41 }
42
43 /* Since there is no fixed limit we check whether the size is large
44 enough. */
45 char *res = __realpath (buf, NULL);
46 if (res != NULL)
47 {
48 size_t actlen = strlen (res) + 1;
49 if (actlen > resolvedlen)
50 __chk_fail ();
51
52 memcpy (resolved, res, actlen);
53 free (res);
54 res = resolved;
55 }
56
57 return res;
58#endif
59}
60