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         unsigned int 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                                 struct dirsort_privates *data)
  45 {
  46         struct stat dir_stat;
  47         unsigned int i;
  48         unsigned int total_count = 0;
  49         struct dirsort_privates *data = NULL;
  50
  51         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
  52                                 return false);
  53
  54         data->number_of_entries = 0;
  55
  56         if (fstat(data->fd, &dir_stat) == 0) {
  57                 data->mtime = dir_stat.st_mtime;
  58         }
  59
  60         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  61                != NULL) {
  62                 total_count++;
  63         }
  64
  65         if (total_count == 0) {
  66                 return false;
  67         }
  68
  69         /* Open the underlying directory and count the number of entries
  70            Skip back to the beginning as we'll read it again */
  71         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
  72
  73         /* Set up an array and read the directory entries into it */
  74         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  75         data->directory_list = talloc_zero_array(data,
  76                                         struct dirent,
  77                                         total_count);
  78         if (!data->directory_list) {
  79                 return false;
  80         }
  81         for (i = 0; i < total_count; i++) {
  82                 struct dirent *dp = SMB_VFS_NEXT_READDIR(handle,
  83                                                 data->source_directory,
  84                                                 NULL);
  85                 if (dp == NULL) {
  86                         break;
  87                 }
  88                 data->directory_list[i] = *dp;
  89         }
  90
  91         data->number_of_entries = i;
  92
  93         /* Sort the directory entries by name */
  94         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
  95         return true;
  96 }
  97
  98 static DIR *dirsort_opendir(vfs_handle_struct *handle,
  99                                        const char *fname, const char *mask,
 100                                        uint32 attr)
 101 {
 102         struct dirsort_privates *data = NULL;
 103
 104         /* set up our private data about this directory */
 105         data = talloc_zero(handle->conn, struct dirsort_privates);
 106         if (!data) {
 107                 return NULL;
 108         }
 109
 110         data->directory_list = NULL;
 111         data->pos = 0;
 112
 113         /* Open the underlying directory and count the number of entries */
 114         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 115                                                       attr);
 116
 117         data->fd = dirfd(data->source_directory);
 118
 119         if (!open_and_sort_dir(handle, data)) {
 120                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 121                 TALLOC_FREE(data);
 122                 return NULL;
 123         }
 124
 125         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 126                                 struct dirsort_privates, return NULL);
 127
 128         return data->source_directory;
 129 }
 130
 131 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 132                                         files_struct *fsp,
 133                                         const char *mask,
 134                                         uint32 attr)
 135 {
 136         struct dirsort_privates *data = NULL;
 137
 138         /* set up our private data about this directory */
 139         data = talloc_zero(handle->conn, struct dirsort_privates);
 140         if (!data) {
 141                 return NULL;
 142         }
 143
 144         data->directory_list = NULL;
 145         data->pos = 0;
 146
 147         /* Open the underlying directory and count the number of entries */
 148         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 149                                                       attr);
 150
 151         if (data->source_directory == NULL) {
 152                 TALLOC_FREE(data);
 153                 return NULL;
 154         }
 155
 156         data->fd = dirfd(data->source_directory);
 157
 158         if (!open_and_sort_dir(handle, data)) {
 159                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 160                 TALLOC_FREE(data);
 161                 /* fd is now closed. */
 162                 fsp->fh->fd = -1;
 163                 return NULL;
 164         }
 165
 166         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 167                                 struct dirsort_privates, return NULL);
 168
 169         return data->source_directory;
 170 }
 171
 172 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 173                                           DIR *dirp,
 174                                           SMB_STRUCT_STAT *sbuf)
 175 {
 176         struct dirsort_privates *data = NULL;
 177         time_t current_mtime;
 178         struct stat dir_stat;
 179
 180         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 181                                 return NULL);
 182
 183         if (fstat(data->fd, &dir_stat) == -1) {
 184                 return NULL;
 185         }
 186
 187         current_mtime = dir_stat.st_mtime;
 188
 189         /* throw away cache and re-read the directory if we've changed */
 190         if (current_mtime > data->mtime) {
 191                 open_and_sort_dir(handle, data);
 192         }
 193
 194         if (data->pos >= data->number_of_entries) {
 195                 return NULL;
 196         }
 197
 198         return &data->directory_list[data->pos++];
 199 }
 200
 201 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 202                             long offset)
 203 {
 204         struct dirsort_privates *data = NULL;
 205         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 206
 207         data->pos = offset;
 208 }
 209
 210 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 211 {
 212         struct dirsort_privates *data = NULL;
 213         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 214                                 return -1);
 215
 216         return data->pos;
 217 }
 218
 219 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 220 {
 221         struct dirsort_privates *data = NULL;
 222         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 223
 224         data->pos = 0;
 225 }
 226
 227 static struct vfs_fn_pointers vfs_dirsort_fns = {
 228         .opendir_fn = dirsort_opendir,
 229         .fdopendir_fn = dirsort_fdopendir,
 230         .readdir_fn = dirsort_readdir,
 231         .seekdir_fn = dirsort_seekdir,
 232         .telldir_fn = dirsort_telldir,
 233         .rewind_dir_fn = dirsort_rewinddir,
 234 };
 235
 236 NTSTATUS vfs_dirsort_init(void)
 237 {
 238         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 239                                 &vfs_dirsort_fns);
 240 }