1  /* Read a directory in reentrant mode.  Linux no-LFS version.
       2     Copyright (C) 2018-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <dirent.h>
      20  
      21  #if !_DIRENT_MATCHES_DIRENT64
      22  /* Read a directory entry from DIRP.  */
      23  int
      24  __readdir_r (DIR *dirp, struct dirent *entry, struct dirent **result)
      25  {
      26    struct dirent *dp;
      27    size_t reclen;
      28  
      29    __libc_lock_lock (dirp->lock);
      30  
      31    while (1)
      32      {
      33        dp = __readdir_unlocked (dirp);
      34        if (dp == NULL)
      35  	break;
      36  
      37        reclen = dp->d_reclen;
      38        if (reclen <= offsetof (struct dirent, d_name) + NAME_MAX + 1)
      39  	break;
      40  
      41        /* The record is very long.  It could still fit into the caller-supplied
      42  	 buffer if we can skip padding at the end.  */
      43        size_t namelen = _D_EXACT_NAMLEN (dp);
      44        if (namelen <= NAME_MAX)
      45  	{
      46  	  reclen = offsetof (struct dirent, d_name) + namelen + 1;
      47  	  break;
      48  	}
      49  
      50        /* The name is too long.  Ignore this file.  */
      51        dirp->errcode = ENAMETOOLONG;
      52      }
      53  
      54    if (dp != NULL)
      55      {
      56        *result = memcpy (entry, dp, reclen);
      57        entry->d_reclen = reclen;
      58      }
      59    else
      60      *result = NULL;
      61  
      62    __libc_lock_unlock (dirp->lock);
      63  
      64    return dp != NULL ? 0 : dirp->errcode;
      65  }
      66  
      67  weak_alias (__readdir_r, readdir_r)
      68  #endif /* _DIRENT_MATCHES_DIRENT64  */