sysdeps/mach/hurd/readdir64_r.c

   1 /* Copyright (C) 2001-2016 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 <stddef.h>
  20 #include <string.h>
  21 #include <hurd.h>
  22 #include <hurd/fs.h>
  23 #include <hurd/fd.h>
  24 #include "dirstream.h"
  25
  26 /* Read a directory entry from DIRP.  */
  27 int
  28 __readdir64_r (DIR *dirp, struct dirent64 *entry, struct dirent64 **result)
  29 {
  30   struct dirent64 *dp;
  31   error_t err = 0;
  32
  33   if (dirp == NULL)
  34     {
  35       errno = EINVAL;
  36       return errno;
  37     }
  38
  39   __libc_lock_lock (dirp->__lock);
  40
  41   do
  42     {
  43       if (dirp->__ptr - dirp->__data >= dirp->__size)
  44         {
  45           /* We've emptied out our buffer.  Refill it.  */
  46
  47           char *data = dirp->__data;
  48           int nentries;
  49
  50           if (err = HURD_FD_PORT_USE (dirp->__fd,
  51                                       __dir_readdir (port,
  52                                                      &data, &dirp->__size,
  53                                                      dirp->__entry_ptr,
  54                                                      -1, 0, &nentries)))
  55             {
  56               __hurd_fail (err);
  57               dp = NULL;
  58               break;
  59             }
  60
  61           /* DATA now corresponds to entry index DIRP->__entry_ptr.  */
  62           dirp->__entry_data = dirp->__entry_ptr;
  63
  64           if (data != dirp->__data)
  65             {
  66               /* The data was passed out of line, so our old buffer is no
  67                  longer useful.  Deallocate the old buffer and reset our
  68                  information for the new buffer.  */
  69               __vm_deallocate (__mach_task_self (),
  70                                (vm_address_t) dirp->__data,
  71                                dirp->__allocation);
  72               dirp->__data = data;
  73               dirp->__allocation = round_page (dirp->__size);
  74             }
  75
  76           /* Reset the pointer into the buffer.  */
  77           dirp->__ptr = dirp->__data;
  78
  79           if (nentries == 0)
  80             {
  81               /* End of file.  */
  82               dp = NULL;
  83               break;
  84             }
  85
  86           /* We trust the filesystem to return correct data and so we
  87              ignore NENTRIES.  */
  88         }
  89
  90       dp = (struct dirent64 *) dirp->__ptr;
  91       dirp->__ptr += dp->d_reclen;
  92       ++dirp->__entry_ptr;
  93
  94       /* Loop to ignore deleted files.  */
  95     } while (dp->d_fileno == 0);
  96
  97   if (dp)
  98     {
  99       *entry = *dp;
 100       memcpy (entry->d_name, dp->d_name, dp->d_namlen + 1);
 101       *result = entry;
 102     }
 103   else
 104     *result = NULL;
 105
 106   __libc_lock_unlock (dirp->__lock);
 107
 108   return dp ? 0 : err ? errno : 0;
 109 }
 110
 111 weak_alias (__readdir64_r, readdir64_r)