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 struct smb_filename *smb_fname,
 117                                 const char *mask,
 118                                 uint32_t attr)
 119 {
 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         data->smb_fname = cp_smb_filename(data, smb_fname);
 136         if (data->smb_fname == NULL) {
 137                 TALLOC_FREE(data);
 138                 return NULL;
 139         }
 140
 141         /* Open the underlying directory and count the number of entries */
 142         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, smb_fname, mask,
 143                                                       attr);
 144
 145         if (data->source_directory == NULL) {
 146                 TALLOC_FREE(data);
 147                 return NULL;
 148         }
 149
 150         if (!open_and_sort_dir(handle, data)) {
 151                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 152                 TALLOC_FREE(data);
 153                 return NULL;
 154         }
 155
 156         /* Add to the private list of all open directories. */
 157         DLIST_ADD(list_head, data);
 158         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 159                                 struct dirsort_privates, return NULL);
 160
 161         return data->source_directory;
 162 }
 163
 164 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 165                                         files_struct *fsp,
 166                                         const char *mask,
 167                                         uint32_t attr)
 168 {
 169         struct dirsort_privates *list_head = NULL;
 170         struct dirsort_privates *data = NULL;
 171
 172         if (SMB_VFS_HANDLE_TEST_DATA(handle)) {
 173                 /* Find the list head of all open directories. */
 174                 SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates,
 175                                 return NULL);
 176         }
 177
 178         /* set up our private data about this directory */
 179         data = talloc_zero(handle->conn, struct dirsort_privates);
 180         if (!data) {
 181                 return NULL;
 182         }
 183
 184         data->fsp = fsp;
 185
 186         /* Open the underlying directory and count the number of entries */
 187         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 188                                                       attr);
 189
 190         if (data->source_directory == NULL) {
 191                 TALLOC_FREE(data);
 192                 return NULL;
 193         }
 194
 195         if (!open_and_sort_dir(handle, data)) {
 196                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 197                 TALLOC_FREE(data);
 198                 /* fd is now closed. */
 199                 fsp->fh->fd = -1;
 200                 return NULL;
 201         }
 202
 203         /* Add to the private list of all open directories. */
 204         DLIST_ADD(list_head, data);
 205         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 206                                 struct dirsort_privates, return NULL);
 207
 208         return data->source_directory;
 209 }
 210
 211 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
 212                                           DIR *dirp,
 213                                           SMB_STRUCT_STAT *sbuf)
 214 {
 215         struct dirsort_privates *data = NULL;
 216         struct timespec current_mtime;
 217
 218         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 219                                 return NULL);
 220
 221         while(data && (data->source_directory != dirp)) {
 222                 data = data->next;
 223         }
 224         if (data == NULL) {
 225                 return NULL;
 226         }
 227
 228         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 229                 return NULL;
 230         }
 231
 232         /* throw away cache and re-read the directory if we've changed */
 233         if (timespec_compare(&current_mtime, &data->mtime)) {
 234                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 235                 open_and_sort_dir(handle, data);
 236         }
 237
 238         if (data->pos >= data->number_of_entries) {
 239                 return NULL;
 240         }
 241
 242         return &data->directory_list[data->pos++];
 243 }
 244
 245 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
 246                             long offset)
 247 {
 248         struct timespec current_mtime;
 249         struct dirsort_privates *data = NULL;
 250
 251         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 252
 253         /* Find the entry holding dirp. */
 254         while(data && (data->source_directory != dirp)) {
 255                 data = data->next;
 256         }
 257         if (data == NULL) {
 258                 return;
 259         }
 260         if (offset >= data->number_of_entries) {
 261                 return;
 262         }
 263         data->pos = offset;
 264
 265         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 266                 return;
 267         }
 268
 269         if (timespec_compare(&current_mtime, &data->mtime)) {
 270                 /* Directory changed. We must re-read the
 271                    cache and search for the name that was
 272                    previously stored at the offset being
 273                    requested, otherwise after the re-sort
 274                    we will point to the wrong entry. The
 275                    OS/2 incremental delete code relies on
 276                    this. */
 277                 unsigned int i;
 278                 char *wanted_name = talloc_strdup(handle->conn,
 279                                         data->directory_list[offset].d_name);
 280                 if (wanted_name == NULL) {
 281                         return;
 282                 }
 283                 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
 284                 open_and_sort_dir(handle, data);
 285                 /* Now search for where we were. */
 286                 data->pos = 0;
 287                 for (i = 0; i < data->number_of_entries; i++) {
 288                         if(strcmp(wanted_name, data->directory_list[i].d_name) == 0) {
 289                                 data->pos = i;
 290                                 break;
 291                         }
 292                 }
 293                 TALLOC_FREE(wanted_name);
 294         }
 295 }
 296
 297 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
 298 {
 299         struct dirsort_privates *data = NULL;
 300         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 301                                 return -1);
 302
 303         /* Find the entry holding dirp. */
 304         while(data && (data->source_directory != dirp)) {
 305                 data = data->next;
 306         }
 307         if (data == NULL) {
 308                 return -1;
 309         }
 310         return data->pos;
 311 }
 312
 313 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
 314 {
 315         struct dirsort_privates *data = NULL;
 316         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 317
 318         /* Find the entry holding dirp. */
 319         while(data && (data->source_directory != dirp)) {
 320                 data = data->next;
 321         }
 322         if (data == NULL) {
 323                 return;
 324         }
 325         data->pos = 0;
 326 }
 327
 328 static int dirsort_closedir(vfs_handle_struct *handle, DIR *dirp)
 329 {
 330         struct dirsort_privates *list_head = NULL;
 331         struct dirsort_privates *data = NULL;
 332         int ret;
 333
 334         SMB_VFS_HANDLE_GET_DATA(handle, list_head, struct dirsort_privates, return -1);
 335         /* Find the entry holding dirp. */
 336         for(data = list_head; data && (data->source_directory != dirp); data = data->next) {
 337                 ;
 338         }
 339         if (data == NULL) {
 340                 return -1;
 341         }
 342         /* Remove from the list and re-store the list head. */
 343         DLIST_REMOVE(list_head, data);
 344         SMB_VFS_HANDLE_SET_DATA(handle, list_head, NULL,
 345                                 struct dirsort_privates, return -1);
 346
 347         ret = SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
 348         TALLOC_FREE(data);
 349         return ret;
 350 }
 351
 352 static struct vfs_fn_pointers vfs_dirsort_fns = {
 353         .opendir_fn = dirsort_opendir,
 354         .fdopendir_fn = dirsort_fdopendir,
 355         .readdir_fn = dirsort_readdir,
 356         .seekdir_fn = dirsort_seekdir,
 357         .telldir_fn = dirsort_telldir,
 358         .rewind_dir_fn = dirsort_rewinddir,
 359         .closedir_fn = dirsort_closedir,
 360 };
 361
 362 static_decl_vfs;
 363 NTSTATUS vfs_dirsort_init(void)
 364 {
 365         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 366                                 &vfs_dirsort_fns);
 367 }