1: /* Copyright (C) 2005 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, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.  */
   18: 
   19: #include <limits.h>
   20: #include <stdlib.h>
   21: #include <string.h>
   22: #include <unistd.h>
   23: 
   24: 
   25: char *
   26: __realpath_chk (const char *buf, char *resolved, size_t resolvedlen)
   27: {
   28: #ifdef PATH_MAX
   29:   if (resolvedlen < PATH_MAX)
   30:     __chk_fail ();
   31: 
   32:   return __realpath (buf, resolved);
   33: #else
   34:   long int pathmax =__pathconf (buf, _PC_PATH_MAX);
   35:   if (pathmax != -1)
   36:     {
   37:       /* We do have a fixed limit.  */
   38:       if (resolvedlen < pathmax)
   39:         __chk_fail ();
   40: 
   41:       return __realpath (buf, resolved);
   42:     }
   43: 
   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)
   48:     {
   49:       size_t actlen = strlen (res) + 1;
   50:       if (actlen > resolvedlen)
   51:         __chk_fail ();
   52: 
   53:       memcpy (resolved, res, actlen);
   54:       free (res);
   55:       res = resolved;
   56:     }
   57: 
   58:   return res;
   59: #endif
   60: }