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         struct timespec mtime;
  35         DIR *source_directory;
  36         files_struct *fsp; /* If open via FDOPENDIR. */
  37         struct smb_filename *smb_fname; /* If open via OPENDIR */
  38 };
  39
  40 static void free_dirsort_privates(void **datap) {
  41         TALLOC_FREE(*datap);
  42 }
  43
  44 static bool get_sorted_dir_mtime(vfs_handle_struct *handle,
  45                                 struct dirsort_privates *data,
  46                                 struct timespec *ret_mtime)
  47 {
  48         int ret;
  49         struct timespec mtime;
  50
  51         if (data->fsp) {
  52                 ret = fsp_stat(data->fsp);
  53                 mtime = data->fsp->fsp_name->st.st_ex_mtime;
  54         } else {
  55                 ret = SMB_VFS_STAT(handle->conn, data->smb_fname);
  56                 mtime = data->smb_fname->st.st_ex_mtime;
  57         }
  58
  59         if (ret == -1) {
  60                 return false;
  61         }
  62
  63         *ret_mtime = mtime;
  64
  65         return true;
  66 }
  67
  68 static bool open_and_sort_dir(vfs_handle_struct *handle,
  69                                 struct dirsort_privates *data)
  70 {
  71         unsigned int i = 0;
  72         unsigned int total_count = 0;
  73
  74         data->number_of_entries = 0;
  75
  76         if (get_sorted_dir_mtime(handle, data, &data->mtime) == false) {
  77                 return false;
  78         }
  79
  80         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  81                != NULL) {
  82                 total_count++;
  83         }
  84
  85         if (total_count == 0) {
  86                 return false;
  87         }
  88
  89         /* Open the underlying directory and count the number of entries
  90            Skip back to the beginning as we'll read it again */
  91         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
  92
  93         /* Set up an array and read the directory entries into it */
  94         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  95         data->directory_list = talloc_zero_array(data,
  96                                         struct dirent,
  97                                         total_count);
  98         if (!data->directory_list) {
  99                 return false;
 100         }
 101         for (i = 0; i < total_count; i++) {
 102                 struct dirent *dp = SMB_VFS_NEXT_READDIR(handle,
 103                                                 data->source_directory,
 104                                                 NULL);
 105                 if (dp == NULL) {
 106                         break;
 107                 }
 108                 data->directory_list[i] = *dp;
 109         }
 110
 111         data->number_of_entries = i;
 112
 113         /* Sort the directory entries by name */
 114         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
 115         return true;
 116 }
 117
 118 static DIR *dirsort_opendir(vfs_handle_struct *handle,
 119                                        const char *fname, const char *mask,
 120                                        uint32 attr)
 121 {
 122         struct dirsort_privates *data = NULL;
 123
 124         /* set up our private data about this directory */
 125         data = talloc_zero(handle->conn, struct dirsort_privates);
 126         if (!data) {
 127                 return NULL;
 128         }
 129
 130         data->smb_fname = synthetic_smb_fname(data, fname, NULL, NULL);
 131         if (data->smb_fname == NULL) {
 132                 TALLOC_FREE(data);
 133                 return NULL;
 134         }
 135
 136         /* Open the underlying directory and count the number of entries */
 137         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 138                                                       attr);
 139
 140         if (data->source_directory == NULL) {
 141                 TALLOC_FREE(data);
 142                 return NULL;
 143         }
 144
 145         if (!open_and_sort_dir(handle, data)) {
 146                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 147                 TALLOC_FREE(data);
 148                 return NULL;
 149         }
 150
 151         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 152                                 struct dirsort_privates, return NULL);
 153
 154         return data->source_directory;
 155 }
 156
 157 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 158                                         files_struct *fsp,
 159                                         const char *mask,
 160                                         uint32 attr)
 161 {
 162         struct dirsort_privates *data = NULL;
 163
 164         /* set up our private data about this directory */
 165         data = talloc_zero(handle->conn, struct dirsort_privates);
 166         if (!data) {
 167                 return NULL;
 168         }
 169
 170         data->fsp = fsp;
 171
 172         /* Open the underlying directory and count the number of entries */
 173         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 174                                                       attr);
 175
 176         if (data->source_directory == NULL) {
 177                 TALLOC_FREE(data);
 178                 return NULL;
 179         }
 180
 181         if (!open_and_sort_dir(handle, data)) {
 182                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 183                 TALLOC_FREE(data);
 184                 /* fd is now closed. */
 185                 fsp->fh->fd = -1;
 186                 return NULL;
 187         }
 188
 189         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 190                                 struct dirsort_privates, return NULL);
 191
 192         return data->source_directory;
 193 }
 194
 195 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 196                                           DIR *dirp,
 197                                           SMB_STRUCT_STAT *sbuf)
 198 {
 199         struct dirsort_privates *data = NULL;
 200         struct timespec current_mtime;
 201
 202         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 203                                 return NULL);
 204
 205         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 206                 return NULL;
 207         }
 208
 209         /* throw away cache and re-read the directory if we've changed */
 210         if (timespec_compare(&current_mtime, &data->mtime) > 1) {
 211                 open_and_sort_dir(handle, data);
 212         }
 213
 214         if (data->pos >= data->number_of_entries) {
 215                 return NULL;
 216         }
 217
 218         return &data->directory_list[data->pos++];
 219 }
 220
 221 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 222                             long offset)
 223 {
 224         struct dirsort_privates *data = NULL;
 225         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 226
 227         data->pos = offset;
 228 }
 229
 230 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 231 {
 232         struct dirsort_privates *data = NULL;
 233         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 234                                 return -1);
 235
 236         return data->pos;
 237 }
 238
 239 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 240 {
 241         struct dirsort_privates *data = NULL;
 242         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 243
 244         data->pos = 0;
 245 }
 246
 247 static struct vfs_fn_pointers vfs_dirsort_fns = {
 248         .opendir_fn = dirsort_opendir,
 249         .fdopendir_fn = dirsort_fdopendir,
 250         .readdir_fn = dirsort_readdir,
 251         .seekdir_fn = dirsort_seekdir,
 252         .telldir_fn = dirsort_telldir,
 253         .rewind_dir_fn = dirsort_rewinddir,
 254 };
 255
 256 NTSTATUS vfs_dirsort_init(void)
 257 {
 258         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 259                                 &vfs_dirsort_fns);
 260 }