lib/opendir.c

   1 /* Start reading the entries of a directory.
   2    Copyright (C) 2006-2018 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 /* Specification.  */
  20 #include <dirent.h>
  21
  22 #include <errno.h>
  23 #include <stddef.h>
  24
  25 #if HAVE_OPENDIR
  26
  27 /* Override opendir(), to keep track of the open file descriptors.
  28    Needed because there is a function dirfd().  */
  29
  30 #else
  31
  32 # include <stdlib.h>
  33
  34 # include "dirent-private.h"
  35 # include "filename.h"
  36
  37 #endif
  38
  39 #if REPLACE_FCHDIR
  40 # include <unistd.h>
  41 #endif
  42
  43 #ifdef __KLIBC__
  44 # include <io.h>
  45 # include <fcntl.h>
  46 #endif
  47
  48 DIR *
  49 opendir (const char *dir_name)
  50 {
  51 #if HAVE_OPENDIR
  52 # undef opendir
  53   DIR *dirp;
  54
  55   dirp = opendir (dir_name);
  56   if (dirp == NULL)
  57     return NULL;
  58
  59 # ifdef __KLIBC__
  60   {
  61     int fd = open (dir_name, O_RDONLY);
  62     if (fd == -1 || _gl_register_dirp_fd (fd, dirp))
  63       {
  64         int saved_errno = errno;
  65
  66         close (fd);
  67         closedir (dirp);
  68
  69         errno = saved_errno;
  70
  71         return NULL;
  72       }
  73   }
  74 # endif
  75 #else
  76
  77   char dir_name_mask[MAX_PATH + 1 + 1 + 1];
  78   int status;
  79   HANDLE current;
  80   WIN32_FIND_DATA entry;
  81   struct gl_directory *dirp;
  82
  83   if (dir_name[0] == '\0')
  84     {
  85       errno = ENOENT;
  86       return NULL;
  87     }
  88
  89   /* Make the dir_name absolute, so that we continue reading the same
  90      directory if the current directory changed between this opendir()
  91      call and a subsequent rewinddir() call.  */
  92   if (!GetFullPathName (dir_name, MAX_PATH, dir_name_mask, NULL))
  93     {
  94       errno = EINVAL;
  95       return NULL;
  96     }
  97
  98   /* Append the mask.
  99      "*" and "*.*" appear to be equivalent.  */
 100   {
 101     char *p;
 102
 103     p = dir_name_mask + strlen (dir_name_mask);
 104     if (p > dir_name_mask && !ISSLASH (p[-1]))
 105       *p++ = '\\';
 106     *p++ = '*';
 107     *p = '\0';
 108   }
 109
 110   /* Start searching the directory.  */
 111   status = -1;
 112   current = FindFirstFile (dir_name_mask, &entry);
 113   if (current == INVALID_HANDLE_VALUE)
 114     {
 115       switch (GetLastError ())
 116         {
 117         case ERROR_FILE_NOT_FOUND:
 118           status = -2;
 119           break;
 120         case ERROR_PATH_NOT_FOUND:
 121           errno = ENOENT;
 122           return NULL;
 123         case ERROR_DIRECTORY:
 124           errno = ENOTDIR;
 125           return NULL;
 126         case ERROR_ACCESS_DENIED:
 127           errno = EACCES;
 128           return NULL;
 129         default:
 130           errno = EIO;
 131           return NULL;
 132         }
 133     }
 134
 135   /* Allocate the result.  */
 136   dirp =
 137     (struct gl_directory *)
 138     malloc (offsetof (struct gl_directory, dir_name_mask[0])
 139             + strlen (dir_name_mask) + 1);
 140   if (dirp == NULL)
 141     {
 142       if (current != INVALID_HANDLE_VALUE)
 143         FindClose (current);
 144       errno = ENOMEM;
 145       return NULL;
 146     }
 147   dirp->status = status;
 148   dirp->current = current;
 149   if (status == -1)
 150     memcpy (&dirp->entry, &entry, sizeof (WIN32_FIND_DATA));
 151   strcpy (dirp->dir_name_mask, dir_name_mask);
 152
 153 #endif
 154
 155 #if REPLACE_FCHDIR
 156   {
 157     int fd = dirfd (dirp);
 158     if (0 <= fd && _gl_register_fd (fd, dir_name) != fd)
 159       {
 160         int saved_errno = errno;
 161         closedir (dirp);
 162         errno = saved_errno;
 163         return NULL;
 164       }
 165   }
 166 #endif
 167
 168   return dirp;
 169 }