sysdeps/unix/fdopendir.c

   1 /* Copyright (C) 2005, 2006, 2011 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <dirent.h>
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <sys/stat.h>
  22
  23 #include <not-cancel.h>
  24
  25
  26 DIR *
  27 __fdopendir (int fd)
  28 {
  29   struct stat64 statbuf;
  30
  31   if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &statbuf), 0) < 0)
  32     return NULL;
  33   if (__builtin_expect (! S_ISDIR (statbuf.st_mode), 0))
  34     {
  35       __set_errno (ENOTDIR);
  36       return NULL;
  37     }
  38
  39   /* Make sure the descriptor allows for reading.  */
  40   int flags = __fcntl (fd, F_GETFL);
  41   if (__builtin_expect (flags == -1, 0))
  42     return NULL;
  43   if (__builtin_expect ((flags & O_ACCMODE) == O_WRONLY, 0))
  44     {
  45       __set_errno (EINVAL);
  46       return NULL;
  47     }
  48
  49   return __alloc_dir (fd, false, flags, &statbuf);
  50 }
  51 weak_alias (__fdopendir, fdopendir)