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 SMB_STRUCT_DIRENT *da, const SMB_STRUCT_DIRENT *db)
  26 {
  27         return StrCaseCmp(da->d_name, db->d_name);
  28 }
  29
  30 struct dirsort_privates {
  31         long pos;
  32         SMB_STRUCT_DIRENT *directory_list;
  33         unsigned int number_of_entries;
  34         time_t mtime;
  35         SMB_STRUCT_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 stat dir_stat;
  46         unsigned int i;
  47         unsigned int total_count = 0;
  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                 total_count++;
  62         }
  63
  64         if (total_count == 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                                                  SMB_STRUCT_DIRENT,
  76                                                  total_count);
  77         if (!data->directory_list) {
  78                 return false;
  79         }
  80         for (i = 0; i < total_count; i++) {
  81                 SMB_STRUCT_DIRENT *dp = SMB_VFS_NEXT_READDIR(handle,
  82                                                 data->source_directory,
  83                                                 NULL);
  84                 if (dp == NULL) {
  85                         break;
  86                 }
  87                 data->directory_list[i] = *dp;
  88         }
  89
  90         data->number_of_entries = i;
  91
  92         /* Sort the directory entries by name */
  93         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
  94         return true;
  95 }
  96
  97 static SMB_STRUCT_DIR *dirsort_opendir(vfs_handle_struct *handle,
  98                                        const char *fname, const char *mask,
  99                                        uint32 attr)
 100 {
 101         struct dirsort_privates *data = NULL;
 102
 103         /* set up our private data about this directory */
 104         data = talloc_zero(handle->conn, struct dirsort_privates);
 105         if (!data) {
 106                 return NULL;
 107         }
 108
 109         data->directory_list = NULL;
 110         data->pos = 0;
 111
 112         /* Open the underlying directory and count the number of entries */
 113         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 114                                                       attr);
 115
 116         data->fd = dirfd(data->source_directory);
 117
 118         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 119                                 struct dirsort_privates, return NULL);
 120
 121         if (!open_and_sort_dir(handle)) {
 122                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 123                 return NULL;
 124         }
 125
 126         return data->source_directory;
 127 }
 128
 129 static SMB_STRUCT_DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 130                                         files_struct *fsp,
 131                                         const char *mask,
 132                                         uint32 attr)
 133 {
 134         struct dirsort_privates *data = NULL;
 135
 136         /* set up our private data about this directory */
 137         data = talloc_zero(handle->conn, struct dirsort_privates);
 138         if (!data) {
 139                 return NULL;
 140         }
 141
 142         data->directory_list = NULL;
 143         data->pos = 0;
 144
 145         /* Open the underlying directory and count the number of entries */
 146         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 147                                                       attr);
 148
 149         if (data->source_directory == NULL) {
 150                 TALLOC_FREE(data);
 151                 return NULL;
 152         }
 153
 154         data->fd = dirfd(data->source_directory);
 155
 156         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 157                                 struct dirsort_privates, return NULL);
 158
 159         if (!open_and_sort_dir(handle)) {
 160                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 161                 /* fd is now closed. */
 162                 fsp->fh->fd = -1;
 163                 return NULL;
 164         }
 165
 166         return data->source_directory;
 167 }
 168
 169 static SMB_STRUCT_DIRENT *dirsort_readdir(vfs_handle_struct *handle,
 170                                           SMB_STRUCT_DIR *dirp,
 171                                           SMB_STRUCT_STAT *sbuf)
 172 {
 173         struct dirsort_privates *data = NULL;
 174         time_t current_mtime;
 175         struct stat dir_stat;
 176
 177         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 178                                 return NULL);
 179
 180         if (fstat(data->fd, &dir_stat) == -1) {
 181                 return NULL;
 182         }
 183
 184         current_mtime = dir_stat.st_mtime;
 185
 186         /* throw away cache and re-read the directory if we've changed */
 187         if (current_mtime > data->mtime) {
 188                 open_and_sort_dir(handle);
 189         }
 190
 191         if (data->pos >= data->number_of_entries) {
 192                 return NULL;
 193         }
 194
 195         return &data->directory_list[data->pos++];
 196 }
 197
 198 static void dirsort_seekdir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp,
 199                             long offset)
 200 {
 201         struct dirsort_privates *data = NULL;
 202         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 203
 204         data->pos = offset;
 205 }
 206
 207 static long dirsort_telldir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
 208 {
 209         struct dirsort_privates *data = NULL;
 210         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 211                                 return -1);
 212
 213         return data->pos;
 214 }
 215
 216 static void dirsort_rewinddir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
 217 {
 218         struct dirsort_privates *data = NULL;
 219         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 220
 221         data->pos = 0;
 222 }
 223
 224 static struct vfs_fn_pointers vfs_dirsort_fns = {
 225         .opendir = dirsort_opendir,
 226         .fdopendir = dirsort_fdopendir,
 227         .readdir = dirsort_readdir,
 228         .seekdir = dirsort_seekdir,
 229         .telldir = dirsort_telldir,
 230         .rewind_dir = dirsort_rewinddir,
 231 };
 232
 233 NTSTATUS vfs_dirsort_init(void)
 234 {
 235         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 236                                 &vfs_dirsort_fns);
 237 }