1  /* Copyright (C) 2005-2023 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 <dirent.h>
      19  #include <errno.h>
      20  #include <fcntl.h>
      21  #include <stddef.h>
      22  #include <sys/stat.h>
      23  
      24  #include <not-cancel.h>
      25  
      26  
      27  DIR *
      28  __fdopendir (int fd)
      29  {
      30    struct __stat64_t64 statbuf;
      31  
      32    if (__glibc_unlikely (__fstat64_time64 (fd, &statbuf) < 0))
      33      return NULL;
      34    if (__glibc_unlikely (! S_ISDIR (statbuf.st_mode)))
      35      {
      36        __set_errno (ENOTDIR);
      37        return NULL;
      38      }
      39  
      40    /* Make sure the descriptor allows for reading.  */
      41    int flags = __fcntl64_nocancel (fd, F_GETFL);
      42    if (__glibc_unlikely (flags == -1))
      43      return NULL;
      44    if (__glibc_unlikely ((flags & O_ACCMODE) == O_WRONLY))
      45      {
      46        __set_errno (EINVAL);
      47        return NULL;
      48      }
      49  
      50    return __alloc_dir (fd, false, flags, &statbuf);
      51  }
      52  weak_alias (__fdopendir, fdopendir)