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         struct dirsort_privates *list_head = NULL;
 120         struct dirsort_privates *data = NULL;
 121
 122         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 123                 /* Find the list head of all open directories. */
 124                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 125                                 return NULL);
 126         }
 127
 128         /* set up our private data about this directory */
 129         data = talloc_zero(handle->conn, struct dirsort_privates);
 130         if (!data) {
 131                 return NULL;
 132         }
 133
 134         data->smb_fname = synthetic_smb_fname(data, fname, NULL, NULL);
 135         if (data->smb_fname == NULL) {
 136                 TALLOC_FREE(data);
 137                 return NULL;
 138         }
 139
 140         /* Open the underlying directory and count the number of entries */
 141         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 142                                                       attr);
 143
 144         if (data->source_directory == NULL) {
 145                 TALLOC_FREE(data);
 146                 return NULL;
 147         }
 148
 149         if (!open_and_sort_dir(handle, data)) {
 150                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 151                 TALLOC_FREE(data);
 152                 return NULL;
 153         }
 154
 155         /* Add to the private list of all open directories. */
 156         DLIST_ADD(list_head, data);
 157         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 158                                 struct dirsort_privates, return NULL);
 159
 160         return data->source_directory;
 161 }
 162
 163 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 164                                         files_struct *fsp,
 165                                         const char *mask,
 166                                         uint32 attr)
 167 {
 168         struct dirsort_privates *list_head = NULL;
 169         struct dirsort_privates *data = NULL;
 170
 171         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 172                 /* Find the list head of all open directories. */
 173                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 174                                 return NULL);
 175         }
 176
 177         /* set up our private data about this directory */
 178         data = talloc_zero(handle->conn, struct dirsort_privates);
 179         if (!data) {
 180                 return NULL;
 181         }
 182
 183         data->fsp = fsp;
 184
 185         /* Open the underlying directory and count the number of entries */
 186         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 187                                                       attr);
 188
 189         if (data->source_directory == NULL) {
 190                 TALLOC_FREE(data);
 191                 return NULL;
 192         }
 193
 194         if (!open_and_sort_dir(handle, data)) {
 195                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 196                 TALLOC_FREE(data);
 197                 /* fd is now closed. */
 198                 fsp->fh->fd = -1;
 199                 return NULL;
 200         }
 201
 202         /* Add to the private list of all open directories. */
 203         DLIST_ADD(list_head, data);
 204         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 205                                 struct dirsort_privates, return NULL);
 206
 207         return data->source_directory;
 208 }
 209
 210 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 211                                           DIR *dirp,
 212                                           SMB_STRUCT_STAT *sbuf)
 213 {
 214         struct dirsort_privates *data = NULL;
 215         struct timespec current_mtime;
 216
 217         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 218                                 return NULL);
 219
 220         while(data && (data->source_directory != dirp)) {
 221                 data = data->next;
 222         }
 223         if (data == NULL) {
 224                 return NULL;
 225         }
 226
 227         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 228                 return NULL;
 229         }
 230
 231         /* throw away cache and re-read the directory if we've changed */
 232         if (timespec_compare(&current_mtime, &data->mtime)) {
 233                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 234                 open_and_sort_dir(handle, data);
 235         }
 236
 237         if (data->pos >= data->number_of_entries) {
 238                 return NULL;
 239         }
 240
 241         return &data->directory_list[data->pos++];
 242 }
 243
 244 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 245                             long offset)
 246 {
 247         struct timespec current_mtime;
 248         struct dirsort_privates *data = NULL;
 249
 250         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 251
 252         /* Find the entry holding dirp. */
 253         while(data && (data->source_directory != dirp)) {
 254                 data = data->next;
 255         }
 256         if (data == NULL) {
 257                 return;
 258         }
 259         if (offset > data->number_of_entries) {
 260                 return;
 261         }
 262         data->pos = offset;
 263
 264         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 265                 return;
 266         }
 267
 268         if (timespec_compare(&current_mtime, &data->mtime)) {
 269                 /* Directory changed. We must re-read the
 270                    cache and search for the name that was
 271                    previously stored at the offset being
 272                    requested, otherwise after the re-sort
 273                    we will point to the wrong entry. The
 274                    OS/2 incremental delete code relies on
 275                    this. */
 276                 unsigned int i;
 277                 char *wanted_name = talloc_strdup(handle->conn,
 278                                         data->directory_list[offset].d_name);
 279                 if (wanted_name == NULL) {
 280                         return;
 281                 }
 282                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 283                 open_and_sort_dir(handle, data);
 284                 /* Now search for where we were. */
 285                 data->pos = 0;
 286                 for (i = 0; i < data->number_of_entries; i++) {
 287                         if(strcmp(wanted_name, data->directory_list[i].d_name) == 0) {
 288                                 data->pos = i;
 289                                 break;
 290                         }
 291                 }
 292                 TALLOC_FREE(wanted_name);
 293         }
 294 }
 295
 296 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 297 {
 298         struct dirsort_privates *data = NULL;
 299         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 300                                 return -1);
 301
 302         /* Find the entry holding dirp. */
 303         while(data && (data->source_directory != dirp)) {
 304                 data = data->next;
 305         }
 306         if (data == NULL) {
 307                 return -1;
 308         }
 309         return data->pos;
 310 }
 311
 312 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 313 {
 314         struct dirsort_privates *data = NULL;
 315         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 316
 317         /* Find the entry holding dirp. */
 318         while(data && (data->source_directory != dirp)) {
 319                 data = data->next;
 320         }
 321         if (data == NULL) {
 322                 return;
 323         }
 324         data->pos = 0;
 325 }
 326
 327 static int dirsort_closedir(vfs_handle_struct *handle, DIR *dirp)
 328 {
 329         struct dirsort_privates *list_head = NULL;
 330         struct dirsort_privates *data = NULL;
 331         int ret;
 332
 333         SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates, return -1);
 334         /* Find the entry holding dirp. */
 335         for(data = list_head; data && (data->source_directory != dirp); data = data->next) {
 336                 ;
 337         }
 338         if (data == NULL) {
 339                 return -1;
 340         }
 341         /* Remove from the list and re-store the list head. */
 342         DLIST_REMOVE(list_head, data);
 343         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 344                                 struct dirsort_privates, return -1);
 345
 346         ret = SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
 347         TALLOC_FREE(data);
 348         return ret;
 349 }
 350
 351 static struct vfs_fn_pointers vfs_dirsort_fns = {
 352         .opendir_fn = dirsort_opendir,
 353         .fdopendir_fn = dirsort_fdopendir,
 354         .readdir_fn = dirsort_readdir,
 355         .seekdir_fn = dirsort_seekdir,
 356         .telldir_fn = dirsort_telldir,
 357         .rewind_dir_fn = dirsort_rewinddir,
 358         .closedir_fn = dirsort_closedir,
 359 };
 360
 361 NTSTATUS vfs_dirsort_init(void)
 362 {
 363         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 364                                 &vfs_dirsort_fns);
 365 }