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         struct dirsort_privates *prev, *next;
  32         long pos;
  33         struct dirent *directory_list;
  34         unsigned int number_of_entries;
  35         struct timespec mtime;
  36         DIR *source_directory;
  37         files_struct *fsp; /* If open via FDOPENDIR. */
  38         struct smb_filename *smb_fname; /* If open via OPENDIR */
  39 };
  40
  41 static bool get_sorted_dir_mtime(vfs_handle_struct *handle,
  42                                 struct dirsort_privates *data,
  43                                 struct timespec *ret_mtime)
  44 {
  45         int ret;
  46         struct timespec mtime;
  47
  48         if (data->fsp) {
  49                 ret = fsp_stat(data->fsp);
  50                 mtime = data->fsp->fsp_name->st.st_ex_mtime;
  51         } else {
  52                 ret = SMB_VFS_STAT(handle->conn, data->smb_fname);
  53                 mtime = data->smb_fname->st.st_ex_mtime;
  54         }
  55
  56         if (ret == -1) {
  57                 return false;
  58         }
  59
  60         *ret_mtime = mtime;
  61
  62         return true;
  63 }
  64
  65 static bool open_and_sort_dir(vfs_handle_struct *handle,
  66                                 struct dirsort_privates *data)
  67 {
  68         unsigned int i = 0;
  69         unsigned int total_count = 0;
  70
  71         data->number_of_entries = 0;
  72
  73         if (get_sorted_dir_mtime(handle, data, &data->mtime) == false) {
  74                 return false;
  75         }
  76
  77         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  78                != NULL) {
  79                 total_count++;
  80         }
  81
  82         if (total_count == 0) {
  83                 return false;
  84         }
  85
  86         /* Open the underlying directory and count the number of entries
  87            Skip back to the beginning as we'll read it again */
  88         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
  89
  90         /* Set up an array and read the directory entries into it */
  91         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  92         data->directory_list = talloc_zero_array(data,
  93                                         struct dirent,
  94                                         total_count);
  95         if (!data->directory_list) {
  96                 return false;
  97         }
  98         for (i = 0; i < total_count; i++) {
  99                 struct dirent *dp = SMB_VFS_NEXT_READDIR(handle,
 100                                                 data->source_directory,
 101                                                 NULL);
 102                 if (dp == NULL) {
 103                         break;
 104                 }
 105                 data->directory_list[i] = *dp;
 106         }
 107
 108         data->number_of_entries = i;
 109
 110         /* Sort the directory entries by name */
 111         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
 112         return true;
 113 }
 114
 115 static DIR *dirsort_opendir(vfs_handle_struct *handle,
 116                                        const char *fname, const char *mask,
 117                                        uint32 attr)
 118 {
 119         NTSTATUS status;
 120         struct dirsort_privates *list_head = NULL;
 121         struct dirsort_privates *data = NULL;
 122
 123         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 124                 /* Find the list head of all open directories. */
 125                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 126                                 return NULL);
 127         }
 128
 129         /* set up our private data about this directory */
 130         data = talloc_zero(handle->conn, struct dirsort_privates);
 131         if (!data) {
 132                 return NULL;
 133         }
 134
 135         status = create_synthetic_smb_fname(data,
 136                                         fname,
 137                                         NULL,
 138                                         NULL,
 139                                         &data->smb_fname);
 140         if (!NT_STATUS_IS_OK(status)) {
 141                 TALLOC_FREE(data);
 142                 return NULL;
 143         }
 144
 145         /* Open the underlying directory and count the number of entries */
 146         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 147                                                       attr);
 148
 149         if (data->source_directory == NULL) {
 150                 TALLOC_FREE(data);
 151                 return NULL;
 152         }
 153
 154         if (!open_and_sort_dir(handle, data)) {
 155                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 156                 TALLOC_FREE(data);
 157                 return NULL;
 158         }
 159
 160         /* Add to the private list of all open directories. */
 161         DLIST_ADD(list_head, data);
 162         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 163                                 struct dirsort_privates, return NULL);
 164
 165         return data->source_directory;
 166 }
 167
 168 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 169                                         files_struct *fsp,
 170                                         const char *mask,
 171                                         uint32 attr)
 172 {
 173         struct dirsort_privates *list_head = NULL;
 174         struct dirsort_privates *data = NULL;
 175
 176         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 177                 /* Find the list head of all open directories. */
 178                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 179                                 return NULL);
 180         }
 181
 182         /* set up our private data about this directory */
 183         data = talloc_zero(handle->conn, struct dirsort_privates);
 184         if (!data) {
 185                 return NULL;
 186         }
 187
 188         data->fsp = fsp;
 189
 190         /* Open the underlying directory and count the number of entries */
 191         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 192                                                       attr);
 193
 194         if (data->source_directory == NULL) {
 195                 TALLOC_FREE(data);
 196                 return NULL;
 197         }
 198
 199         if (!open_and_sort_dir(handle, data)) {
 200                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 201                 TALLOC_FREE(data);
 202                 /* fd is now closed. */
 203                 fsp->fh->fd = -1;
 204                 return NULL;
 205         }
 206
 207         /* Add to the private list of all open directories. */
 208         DLIST_ADD(list_head, data);
 209         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 210                                 struct dirsort_privates, return NULL);
 211
 212         return data->source_directory;
 213 }
 214
 215 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 216                                           DIR *dirp,
 217                                           SMB_STRUCT_STAT *sbuf)
 218 {
 219         struct dirsort_privates *data = NULL;
 220         struct timespec current_mtime;
 221
 222         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 223                                 return NULL);
 224
 225         while(data && (data->source_directory != dirp)) {
 226                 data = data->next;
 227         }
 228         if (data == NULL) {
 229                 return NULL;
 230         }
 231
 232         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 233                 return NULL;
 234         }
 235
 236         /* throw away cache and re-read the directory if we've changed */
 237         if (timespec_compare(&current_mtime, &data->mtime)) {
 238                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 239                 open_and_sort_dir(handle, data);
 240         }
 241
 242         if (data->pos >= data->number_of_entries) {
 243                 return NULL;
 244         }
 245
 246         return &data->directory_list[data->pos++];
 247 }
 248
 249 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 250                             long offset)
 251 {
 252         struct timespec current_mtime;
 253         struct dirsort_privates *data = NULL;
 254
 255         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 256
 257         /* Find the entry holding dirp. */
 258         while(data && (data->source_directory != dirp)) {
 259                 data = data->next;
 260         }
 261         if (data == NULL) {
 262                 return;
 263         }
 264         if (offset >= data->number_of_entries) {
 265                 return;
 266         }
 267         data->pos = offset;
 268
 269         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 270                 return;
 271         }
 272
 273         if (timespec_compare(&current_mtime, &data->mtime)) {
 274                 /* Directory changed. We must re-read the
 275                    cache and search for the name that was
 276                    previously stored at the offset being
 277                    requested, otherwise after the re-sort
 278                    we will point to the wrong entry. The
 279                    OS/2 incremental delete code relies on
 280                    this. */
 281                 unsigned int i;
 282                 char *wanted_name = talloc_strdup(handle->conn,
 283                                         data->directory_list[offset].d_name);
 284                 if (wanted_name == NULL) {
 285                         return;
 286                 }
 287                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 288                 open_and_sort_dir(handle, data);
 289                 /* Now search for where we were. */
 290                 data->pos = 0;
 291                 for (i = 0; i < data->number_of_entries; i++) {
 292                         if(strcmp(wanted_name, data->directory_list[i].d_name) == 0) {
 293                                 data->pos = i;
 294                                 break;
 295                         }
 296                 }
 297                 TALLOC_FREE(wanted_name);
 298         }
 299 }
 300
 301 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 302 {
 303         struct dirsort_privates *data = NULL;
 304         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 305                                 return -1);
 306
 307         /* Find the entry holding dirp. */
 308         while(data && (data->source_directory != dirp)) {
 309                 data = data->next;
 310         }
 311         if (data == NULL) {
 312                 return -1;
 313         }
 314         return data->pos;
 315 }
 316
 317 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 318 {
 319         struct dirsort_privates *data = NULL;
 320         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 321
 322         /* Find the entry holding dirp. */
 323         while(data && (data->source_directory != dirp)) {
 324                 data = data->next;
 325         }
 326         if (data == NULL) {
 327                 return;
 328         }
 329         data->pos = 0;
 330 }
 331
 332 static int dirsort_closedir(vfs_handle_struct *handle, DIR *dirp)
 333 {
 334         struct dirsort_privates *list_head = NULL;
 335         struct dirsort_privates *data = NULL;
 336         int ret;
 337
 338         SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates, return -1);
 339         /* Find the entry holding dirp. */
 340         for(data = list_head; data && (data->source_directory != dirp); data = data->next) {
 341                 ;
 342         }
 343         if (data == NULL) {
 344                 return -1;
 345         }
 346         /* Remove from the list and re-store the list head. */
 347         DLIST_REMOVE(list_head, data);
 348         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 349                                 struct dirsort_privates, return -1);
 350
 351         ret = SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
 352         TALLOC_FREE(data);
 353         return ret;
 354 }
 355
 356 static struct vfs_fn_pointers vfs_dirsort_fns = {
 357         .opendir_fn = dirsort_opendir,
 358         .fdopendir_fn = dirsort_fdopendir,
 359         .readdir_fn = dirsort_readdir,
 360         .seekdir_fn = dirsort_seekdir,
 361         .telldir_fn = dirsort_telldir,
 362         .rewind_dir_fn = dirsort_rewinddir,
 363         .closedir_fn = dirsort_closedir,
 364 };
 365
 366 NTSTATUS vfs_dirsort_init(void)
 367 {
 368         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 369                                 &vfs_dirsort_fns);
 370 }