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         long 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         struct dirsort_privates *data = (struct dirsort_privates *) *datap;
  41         SAFE_FREE(data->directory_list);
  42         SAFE_FREE(data);
  43         *datap = NULL;
  44
  45         return;
  46 }
  47
  48 static bool open_and_sort_dir (vfs_handle_struct *handle)
  49 {
  50         SMB_STRUCT_DIRENT *dp;
  51         struct stat dir_stat;
  52         long current_pos;
  53         struct dirsort_privates *data = NULL;
  54
  55         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
  56                                 return false);
  57
  58         data->number_of_entries = 0;
  59
  60         if (fstat(data->fd, &dir_stat) == 0) {
  61                 data->mtime = dir_stat.st_mtime;
  62         }
  63
  64         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  65                != NULL) {
  66                 data->number_of_entries++;
  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         SAFE_FREE(data->directory_list); /* destroy previous cache if needed */
  75         data->directory_list = (SMB_STRUCT_DIRENT *)SMB_MALLOC(
  76                 data->number_of_entries * sizeof(SMB_STRUCT_DIRENT));
  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 SMB_STRUCT_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 = (struct dirsort_privates *)SMB_MALLOC(
 101                 sizeof(struct dirsort_privates));
 102
 103         if (!data) {
 104                 return NULL;
 105         }
 106
 107         data->directory_list = NULL;
 108         data->pos = 0;
 109
 110         /* Open the underlying directory and count the number of entries */
 111         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 112                                                       attr);
 113
 114         data->fd = dirfd(data->source_directory);
 115
 116         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 117                                 struct dirsort_privates, return NULL);
 118
 119         if (!open_and_sort_dir(handle)) {
 120                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 121                 return NULL;
 122         }
 123
 124         return data->source_directory;
 125 }
 126
 127 static SMB_STRUCT_DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 128                                         files_struct *fsp,
 129                                         const char *mask,
 130                                         uint32 attr)
 131 {
 132         struct dirsort_privates *data = NULL;
 133
 134         /* set up our private data about this directory */
 135         data = (struct dirsort_privates *)SMB_MALLOC(
 136                 sizeof(struct dirsort_privates));
 137
 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                 SAFE_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 }