source3/modules/vfs_dirsort.c

   1 /*
   2  * VFS module to provide a sorted directory list.
   3  *
   4  * Copyright (C) Andy Kelk (andy@mopoke.co.uk), 2009
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "includes.h"
  22 #include "smbd/smbd.h"
  23 #include "system/filesys.h"
  24
  25 static int compare_dirent (const struct dirent *da, const struct dirent *db)
  26 {
  27         return strcasecmp_m(da->d_name, db->d_name);
  28 }
  29
  30 struct dirsort_privates {
  31         long pos;
  32         struct dirent *directory_list;
  33         long number_of_entries;
  34         time_t mtime;
  35         DIR *source_directory;
  36         int fd;
  37 };
  38
  39 static void free_dirsort_privates(void **datap) {
  40         TALLOC_FREE(*datap);
  41 }
  42
  43 static bool open_and_sort_dir (vfs_handle_struct *handle)
  44 {
  45         struct dirent *dp;
  46         struct stat dir_stat;
  47         long current_pos;
  48         struct dirsort_privates *data = NULL;
  49
  50         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
  51                                 return false);
  52
  53         data->number_of_entries = 0;
  54
  55         if (fstat(data->fd, &dir_stat) == 0) {
  56                 data->mtime = dir_stat.st_mtime;
  57         }
  58
  59         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  60                != NULL) {
  61                 data->number_of_entries++;
  62         }
  63
  64         if (data->number_of_entries == 0) {
  65                 return false;
  66         }
  67
  68         /* Open the underlying directory and count the number of entries
  69            Skip back to the beginning as we'll read it again */
  70         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
  71
  72         /* Set up an array and read the directory entries into it */
  73         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  74         data->directory_list = talloc_zero_array(data,
  75                                         struct dirent,
  76                                         data->number_of_entries);
  77         if (!data->directory_list) {
  78                 return false;
  79         }
  80         current_pos = data->pos;
  81         data->pos = 0;
  82         while ((dp = SMB_VFS_NEXT_READDIR(handle, data->source_directory,
  83                                           NULL)) != NULL) {
  84                 data->directory_list[data->pos++] = *dp;
  85         }
  86
  87         /* Sort the directory entries by name */
  88         data->pos = current_pos;
  89         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
  90         return true;
  91 }
  92
  93 static DIR *dirsort_opendir(vfs_handle_struct *handle,
  94                                        const char *fname, const char *mask,
  95                                        uint32 attr)
  96 {
  97         struct dirsort_privates *data = NULL;
  98
  99         /* set up our private data about this directory */
 100         data = talloc_zero(handle->conn, struct dirsort_privates);
 101         if (!data) {
 102                 return NULL;
 103         }
 104
 105         data->directory_list = NULL;
 106         data->pos = 0;
 107
 108         /* Open the underlying directory and count the number of entries */
 109         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 110                                                       attr);
 111
 112         data->fd = dirfd(data->source_directory);
 113
 114         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 115                                 struct dirsort_privates, return NULL);
 116
 117         if (!open_and_sort_dir(handle)) {
 118                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 119                 return NULL;
 120         }
 121
 122         return data->source_directory;
 123 }
 124
 125 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 126                                         files_struct *fsp,
 127                                         const char *mask,
 128                                         uint32 attr)
 129 {
 130         struct dirsort_privates *data = NULL;
 131
 132         /* set up our private data about this directory */
 133         data = talloc_zero(handle->conn, struct dirsort_privates);
 134         if (!data) {
 135                 return NULL;
 136         }
 137
 138         data->directory_list = NULL;
 139         data->pos = 0;
 140
 141         /* Open the underlying directory and count the number of entries */
 142         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 143                                                       attr);
 144
 145         if (data->source_directory == NULL) {
 146                 TALLOC_FREE(data);
 147                 return NULL;
 148         }
 149
 150         data->fd = dirfd(data->source_directory);
 151
 152         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 153                                 struct dirsort_privates, return NULL);
 154
 155         if (!open_and_sort_dir(handle)) {
 156                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 157                 /* fd is now closed. */
 158                 fsp->fh->fd = -1;
 159                 return NULL;
 160         }
 161
 162         return data->source_directory;
 163 }
 164
 165 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 166                                           DIR *dirp,
 167                                           SMB_STRUCT_STAT *sbuf)
 168 {
 169         struct dirsort_privates *data = NULL;
 170         time_t current_mtime;
 171         struct stat dir_stat;
 172
 173         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 174                                 return NULL);
 175
 176         if (fstat(data->fd, &dir_stat) == -1) {
 177                 return NULL;
 178         }
 179
 180         current_mtime = dir_stat.st_mtime;
 181
 182         /* throw away cache and re-read the directory if we've changed */
 183         if (current_mtime > data->mtime) {
 184                 open_and_sort_dir(handle);
 185         }
 186
 187         if (data->pos >= data->number_of_entries) {
 188                 return NULL;
 189         }
 190
 191         return &data->directory_list[data->pos++];
 192 }
 193
 194 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 195                             long offset)
 196 {
 197         struct dirsort_privates *data = NULL;
 198         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 199
 200         data->pos = offset;
 201 }
 202
 203 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 204 {
 205         struct dirsort_privates *data = NULL;
 206         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 207                                 return -1);
 208
 209         return data->pos;
 210 }
 211
 212 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 213 {
 214         struct dirsort_privates *data = NULL;
 215         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 216
 217         data->pos = 0;
 218 }
 219
 220 static struct vfs_fn_pointers vfs_dirsort_fns = {
 221         .opendir_fn = dirsort_opendir,
 222         .fdopendir_fn = dirsort_fdopendir,
 223         .readdir_fn = dirsort_readdir,
 224         .seekdir_fn = dirsort_seekdir,
 225         .telldir_fn = dirsort_telldir,
 226         .rewind_dir_fn = dirsort_rewinddir,
 227 };
 228
 229 NTSTATUS vfs_dirsort_init(void)
 230 {
 231         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 232                                 &vfs_dirsort_fns);
 233 }