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[glibc/history.git] / debug / realpath_chk.c
blob961aea0b85ad296b04b4b7552b5f963fb54d7853
1 /* Copyright (C) 2005 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
19 #include <limits.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
25 char *
26 __realpath_chk (const char *buf, char *resolved, size_t resolvedlen)
28 #ifdef PATH_MAX
29 if (resolvedlen < PATH_MAX)
30 __chk_fail ();
32 return __realpath (buf, resolved);
33 #else
34 long int pathmax =__pathconf (buf, _PC_PATH_MAX);
35 if (pathmax != -1)
37 /* We do have a fixed limit. */
38 if (resolvedlen < pathmax)
39 __chk_fail ();
41 return __realpath (buf, resolved);
44 /* Since there is no fixed limit we check whether the size is large
45 enough. */
46 char *res = __realpath (buf, NULL);
47 if (res != NULL)
49 size_t actlen = strlen (res) + 1;
50 if (actlen > resolvedlen)
51 __chk_fail ();
53 memcpy (resolved, res, actlen);
54 free (res);
55 res = resolved;
58 return res;
59 #endif