source3/smbd/notify_internal.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Andrew Tridgell 2006
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21   this is the change notify database. It implements mechanisms for
  22   storing current change notify waiters in a tdb, and checking if a
  23   given event matches any of the stored notify waiiters.
  24 */
  25
  26 #include "includes.h"
  27 #include "librpc/gen_ndr/ndr_notify.h"
  28
  29 struct notify_context {
  30         struct db_context *db_recursive;
  31         struct db_context *db_onelevel;
  32         struct server_id server;
  33         struct messaging_context *messaging_ctx;
  34         struct notify_list *list;
  35         struct notify_array *array;
  36         int seqnum;
  37         struct sys_notify_context *sys_notify_ctx;
  38         TDB_DATA key;
  39 };
  40
  41
  42 struct notify_list {
  43         struct notify_list *next, *prev;
  44         void *private_data;
  45         void (*callback)(void *, const struct notify_event *);
  46         void *sys_notify_handle;
  47         int depth;
  48 };
  49
  50 #define NOTIFY_KEY "notify array"
  51
  52 #define NOTIFY_ENABLE           "notify:enable"
  53 #define NOTIFY_ENABLE_DEFAULT   True
  54
  55 static NTSTATUS notify_remove_all(struct notify_context *notify,
  56                                   const struct server_id *server);
  57 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
  58                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
  59
  60 /*
  61   destroy the notify context
  62 */
  63 static int notify_destructor(struct notify_context *notify)
  64 {
  65         messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
  66
  67         if (notify->list != NULL) {
  68                 notify_remove_all(notify, &notify->server);
  69         }
  70
  71         return 0;
  72 }
  73
  74 /*
  75   Open up the notify.tdb database. You should close it down using
  76   talloc_free(). We need the messaging_ctx to allow for notifications
  77   via internal messages
  78 */
  79 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
  80                                    struct messaging_context *messaging_ctx,
  81                                    struct event_context *ev,
  82                                    connection_struct *conn)
  83 {
  84         struct notify_context *notify;
  85
  86         if (!lp_change_notify(conn->params)) {
  87                 return NULL;
  88         }
  89
  90         notify = talloc(mem_ctx, struct notify_context);
  91         if (notify == NULL) {
  92                 return NULL;
  93         }
  94
  95         notify->db_recursive = db_open(notify, lock_path("notify.tdb"),
  96                                        0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST,
  97                                        O_RDWR|O_CREAT, 0644);
  98         if (notify->db_recursive == NULL) {
  99                 talloc_free(notify);
 100                 return NULL;
 101         }
 102
 103         notify->db_onelevel = db_open(notify, lock_path("notify_onelevel.tdb"),
 104                                       0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST,
 105                                       O_RDWR|O_CREAT, 0644);
 106         if (notify->db_onelevel == NULL) {
 107                 talloc_free(notify);
 108                 return NULL;
 109         }
 110
 111         notify->server = server;
 112         notify->messaging_ctx = messaging_ctx;
 113         notify->list = NULL;
 114         notify->array = NULL;
 115         notify->seqnum = notify->db_recursive->get_seqnum(
 116                 notify->db_recursive);
 117         notify->key = string_term_tdb_data(NOTIFY_KEY);
 118
 119         talloc_set_destructor(notify, notify_destructor);
 120
 121         /* register with the messaging subsystem for the notify
 122            message type */
 123         messaging_register(notify->messaging_ctx, notify,
 124                            MSG_PVFS_NOTIFY, notify_handler);
 125
 126         notify->sys_notify_ctx = sys_notify_context_create(conn, notify, ev);
 127
 128         return notify;
 129 }
 130
 131 /*
 132   lock and fetch the record
 133 */
 134 static NTSTATUS notify_fetch_locked(struct notify_context *notify, struct db_record **rec)
 135 {
 136         *rec = notify->db_recursive->fetch_locked(notify->db_recursive,
 137                                                   notify, notify->key);
 138         if (*rec == NULL) {
 139                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 140         }
 141         return NT_STATUS_OK;
 142 }
 143
 144 /*
 145   load the notify array
 146 */
 147 static NTSTATUS notify_load(struct notify_context *notify, struct db_record *rec)
 148 {
 149         TDB_DATA dbuf;
 150         DATA_BLOB blob;
 151         NTSTATUS status;
 152         int seqnum;
 153
 154         seqnum = notify->db_recursive->get_seqnum(notify->db_recursive);
 155
 156         if (seqnum == notify->seqnum && notify->array != NULL) {
 157                 return NT_STATUS_OK;
 158         }
 159
 160         notify->seqnum = seqnum;
 161
 162         talloc_free(notify->array);
 163         notify->array = TALLOC_ZERO_P(notify, struct notify_array);
 164         NT_STATUS_HAVE_NO_MEMORY(notify->array);
 165
 166         if (!rec) {
 167                 if (notify->db_recursive->fetch(notify->db_recursive, notify,
 168                                                 notify->key, &dbuf) != 0) {
 169                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 170                 }
 171         } else {
 172                 dbuf = rec->value;
 173         }
 174
 175         blob.data = (uint8 *)dbuf.dptr;
 176         blob.length = dbuf.dsize;
 177
 178         status = NT_STATUS_OK;
 179         if (blob.length > 0) {
 180                 enum ndr_err_code ndr_err;
 181                 ndr_err = ndr_pull_struct_blob(&blob, notify->array, NULL, notify->array,
 182                                                (ndr_pull_flags_fn_t)ndr_pull_notify_array);
 183                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 184                         status = ndr_map_error2ntstatus(ndr_err);
 185                 }
 186         }
 187
 188         if (DEBUGLEVEL >= 10) {
 189                 DEBUG(10, ("notify_load:\n"));
 190                 NDR_PRINT_DEBUG(notify_array, notify->array);
 191         }
 192
 193         if (!rec) {
 194                 talloc_free(dbuf.dptr);
 195         }
 196
 197         return status;
 198 }
 199
 200 /*
 201   compare notify entries for sorting
 202 */
 203 static int notify_compare(const void *p1, const void *p2)
 204 {
 205         const struct notify_entry *e1 = (const struct notify_entry *)p1;
 206         const struct notify_entry *e2 = (const struct notify_entry *)p2;
 207         return strcmp(e1->path, e2->path);
 208 }
 209
 210 /*
 211   save the notify array
 212 */
 213 static NTSTATUS notify_save(struct notify_context *notify, struct db_record *rec)
 214 {
 215         TDB_DATA dbuf;
 216         DATA_BLOB blob;
 217         NTSTATUS status;
 218         enum ndr_err_code ndr_err;
 219         TALLOC_CTX *tmp_ctx;
 220
 221         /* if possible, remove some depth arrays */
 222         while (notify->array->num_depths > 0 &&
 223                notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
 224                 notify->array->num_depths--;
 225         }
 226
 227         /* we might just be able to delete the record */
 228         if (notify->array->num_depths == 0) {
 229                 return rec->delete_rec(rec);
 230         }
 231
 232         tmp_ctx = talloc_new(notify);
 233         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 234
 235         ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, NULL, notify->array,
 236                                       (ndr_push_flags_fn_t)ndr_push_notify_array);
 237         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 238                 talloc_free(tmp_ctx);
 239                 return ndr_map_error2ntstatus(ndr_err);
 240         }
 241
 242         if (DEBUGLEVEL >= 10) {
 243                 DEBUG(10, ("notify_save:\n"));
 244                 NDR_PRINT_DEBUG(notify_array, notify->array);
 245         }
 246
 247         dbuf.dptr = blob.data;
 248         dbuf.dsize = blob.length;
 249
 250         status = rec->store(rec, dbuf, TDB_REPLACE);
 251         talloc_free(tmp_ctx);
 252
 253         return status;
 254 }
 255
 256
 257 /*
 258   handle incoming notify messages
 259 */
 260 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
 261                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
 262 {
 263         struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
 264         enum ndr_err_code ndr_err;
 265         struct notify_event ev;
 266         TALLOC_CTX *tmp_ctx = talloc_new(notify);
 267         struct notify_list *listel;
 268
 269         if (tmp_ctx == NULL) {
 270                 return;
 271         }
 272
 273         ndr_err = ndr_pull_struct_blob(data, tmp_ctx, NULL, &ev,
 274                                        (ndr_pull_flags_fn_t)ndr_pull_notify_event);
 275         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 276                 talloc_free(tmp_ctx);
 277                 return;
 278         }
 279
 280         for (listel=notify->list;listel;listel=listel->next) {
 281                 if (listel->private_data == ev.private_data) {
 282                         listel->callback(listel->private_data, &ev);
 283                         break;
 284                 }
 285         }
 286
 287         talloc_free(tmp_ctx);
 288 }
 289
 290 /*
 291   callback from sys_notify telling us about changes from the OS
 292 */
 293 static void sys_notify_callback(struct sys_notify_context *ctx,
 294                                 void *ptr, struct notify_event *ev)
 295 {
 296         struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
 297         ev->private_data = listel;
 298         DEBUG(10, ("sys_notify_callback called with action=%d, for %s\n",
 299                    ev->action, ev->path));
 300         listel->callback(listel->private_data, ev);
 301 }
 302
 303 /*
 304   add an entry to the notify array
 305 */
 306 static NTSTATUS notify_add_array(struct notify_context *notify, struct db_record *rec,
 307                                  struct notify_entry *e,
 308                                  void *private_data, int depth)
 309 {
 310         int i;
 311         struct notify_depth *d;
 312         struct notify_entry *ee;
 313
 314         /* possibly expand the depths array */
 315         if (depth >= notify->array->num_depths) {
 316                 d = talloc_realloc(notify->array, notify->array->depth,
 317                                    struct notify_depth, depth+1);
 318                 NT_STATUS_HAVE_NO_MEMORY(d);
 319                 for (i=notify->array->num_depths;i<=depth;i++) {
 320                         ZERO_STRUCT(d[i]);
 321                 }
 322                 notify->array->depth = d;
 323                 notify->array->num_depths = depth+1;
 324         }
 325         d = &notify->array->depth[depth];
 326
 327         /* expand the entries array */
 328         ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
 329                             d->num_entries+1);
 330         NT_STATUS_HAVE_NO_MEMORY(ee);
 331         d->entries = ee;
 332
 333         d->entries[d->num_entries] = *e;
 334         d->entries[d->num_entries].private_data = private_data;
 335         d->entries[d->num_entries].server = notify->server;
 336         d->entries[d->num_entries].path_len = strlen(e->path);
 337         d->num_entries++;
 338
 339         d->max_mask |= e->filter;
 340         d->max_mask_subdir |= e->subdir_filter;
 341
 342         if (d->num_entries > 1) {
 343                 qsort(d->entries, d->num_entries, sizeof(d->entries[0]), notify_compare);
 344         }
 345
 346         /* recalculate the maximum masks */
 347         d->max_mask = 0;
 348         d->max_mask_subdir = 0;
 349
 350         for (i=0;i<d->num_entries;i++) {
 351                 d->max_mask |= d->entries[i].filter;
 352                 d->max_mask_subdir |= d->entries[i].subdir_filter;
 353         }
 354
 355         return notify_save(notify, rec);
 356 }
 357
 358 /*
 359   Add a non-recursive watch
 360 */
 361
 362 static void notify_add_onelevel(struct notify_context *notify,
 363                                 struct notify_entry *e, void *private_data)
 364 {
 365         struct notify_entry_array *array;
 366         struct db_record *rec;
 367         DATA_BLOB blob;
 368         TDB_DATA dbuf;
 369         enum ndr_err_code ndr_err;
 370         NTSTATUS status;
 371
 372         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 373         if (array == NULL) {
 374                 return;
 375         }
 376
 377         rec = notify->db_onelevel->fetch_locked(
 378                 notify->db_onelevel, talloc_tos(),
 379                 make_tdb_data((uint8_t *)&e->dir_id, sizeof(e->dir_id)));
 380         if (rec == NULL) {
 381                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 382                            "\n", file_id_string_tos(&e->dir_id)));
 383                 TALLOC_FREE(array);
 384                 return;
 385         }
 386
 387         blob.data = (uint8_t *)rec->value.dptr;
 388         blob.length = rec->value.dsize;
 389
 390         if (blob.length > 0) {
 391                 ndr_err = ndr_pull_struct_blob(
 392                         &blob, array, NULL, array,
 393                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 394                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 395                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 396                                    ndr_errstr(ndr_err)));
 397                         TALLOC_FREE(array);
 398                         return;
 399                 }
 400                 if (DEBUGLEVEL >= 10) {
 401                         DEBUG(10, ("notify_add_onelevel:\n"));
 402                         NDR_PRINT_DEBUG(notify_entry_array, array);
 403                 }
 404         }
 405
 406         array->entries = talloc_realloc(array, array->entries,
 407                                         struct notify_entry,
 408                                         array->num_entries+1);
 409         if (array->entries == NULL) {
 410                 TALLOC_FREE(array);
 411                 return;
 412         }
 413         array->entries[array->num_entries] = *e;
 414         array->entries[array->num_entries].private_data = private_data;
 415         array->entries[array->num_entries].server = notify->server;
 416         array->num_entries += 1;
 417
 418         ndr_err = ndr_push_struct_blob(
 419                 &blob, rec, NULL, array,
 420                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 421         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 422                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 423                            ndr_errstr(ndr_err)));
 424                 TALLOC_FREE(array);
 425                 return;
 426         }
 427
 428         if (DEBUGLEVEL >= 10) {
 429                 DEBUG(10, ("notify_add_onelevel:\n"));
 430                 NDR_PRINT_DEBUG(notify_entry_array, array);
 431         }
 432
 433         dbuf.dptr = blob.data;
 434         dbuf.dsize = blob.length;
 435
 436         status = rec->store(rec, dbuf, TDB_REPLACE);
 437         TALLOC_FREE(array);
 438         if (!NT_STATUS_IS_OK(status)) {
 439                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 440                            nt_errstr(status)));
 441                 return;
 442         }
 443         e->filter = 0;
 444         return;
 445 }
 446
 447
 448 /*
 449   add a notify watch. This is called when a notify is first setup on a open
 450   directory handle.
 451 */
 452 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 453                     void (*callback)(void *, const struct notify_event *),
 454                     void *private_data)
 455 {
 456         struct notify_entry e = *e0;
 457         NTSTATUS status;
 458         char *tmp_path = NULL;
 459         struct notify_list *listel;
 460         size_t len;
 461         int depth;
 462         struct db_record *rec;
 463
 464         /* see if change notify is enabled at all */
 465         if (notify == NULL) {
 466                 return NT_STATUS_NOT_IMPLEMENTED;
 467         }
 468
 469         status = notify_fetch_locked(notify, &rec);
 470         NT_STATUS_NOT_OK_RETURN(status);
 471
 472         status = notify_load(notify, rec);
 473         if (!NT_STATUS_IS_OK(status)) {
 474                 talloc_free(rec);
 475                 return status;
 476         }
 477
 478         /* cope with /. on the end of the path */
 479         len = strlen(e.path);
 480         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 481                 tmp_path = talloc_strndup(notify, e.path, len-2);
 482                 if (tmp_path == NULL) {
 483                         status = NT_STATUS_NO_MEMORY;
 484                         goto done;
 485                 }
 486                 e.path = tmp_path;
 487         }
 488
 489         depth = count_chars(e.path, '/');
 490
 491         listel = TALLOC_ZERO_P(notify, struct notify_list);
 492         if (listel == NULL) {
 493                 status = NT_STATUS_NO_MEMORY;
 494                 goto done;
 495         }
 496
 497         listel->private_data = private_data;
 498         listel->callback = callback;
 499         listel->depth = depth;
 500         DLIST_ADD(notify->list, listel);
 501
 502         /* ignore failures from sys_notify */
 503         if (notify->sys_notify_ctx != NULL) {
 504                 /*
 505                   this call will modify e.filter and e.subdir_filter
 506                   to remove bits handled by the backend
 507                 */
 508                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 509                                           sys_notify_callback, listel,
 510                                           &listel->sys_notify_handle);
 511                 if (NT_STATUS_IS_OK(status)) {
 512                         talloc_steal(listel, listel->sys_notify_handle);
 513                 }
 514         }
 515
 516         if (e.filter != 0) {
 517                 notify_add_onelevel(notify, &e, private_data);
 518                 status = NT_STATUS_OK;
 519         }
 520
 521         /* if the system notify handler couldn't handle some of the
 522            filter bits, or couldn't handle a request for recursion
 523            then we need to install it in the array used for the
 524            intra-samba notify handling */
 525         if (e.filter != 0 || e.subdir_filter != 0) {
 526                 status = notify_add_array(notify, rec, &e, private_data, depth);
 527         }
 528
 529 done:
 530         talloc_free(rec);
 531         talloc_free(tmp_path);
 532
 533         return status;
 534 }
 535
 536 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 537                                 const struct file_id *fid,
 538                                 void *private_data)
 539 {
 540         struct notify_entry_array *array;
 541         struct db_record *rec;
 542         DATA_BLOB blob;
 543         TDB_DATA dbuf;
 544         enum ndr_err_code ndr_err;
 545         NTSTATUS status;
 546         int i;
 547
 548         if (notify == NULL) {
 549                 return NT_STATUS_NOT_IMPLEMENTED;
 550         }
 551
 552         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 553         if (array == NULL) {
 554                 return NT_STATUS_NO_MEMORY;
 555         }
 556
 557         rec = notify->db_onelevel->fetch_locked(
 558                 notify->db_onelevel, array,
 559                 make_tdb_data((uint8_t *)fid, sizeof(*fid)));
 560         if (rec == NULL) {
 561                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 562                            "\n", file_id_string_tos(fid)));
 563                 TALLOC_FREE(array);
 564                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 565         }
 566
 567         blob.data = (uint8_t *)rec->value.dptr;
 568         blob.length = rec->value.dsize;
 569
 570         if (blob.length > 0) {
 571                 ndr_err = ndr_pull_struct_blob(
 572                         &blob, array, NULL, array,
 573                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 574                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 575                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 576                                    ndr_errstr(ndr_err)));
 577                         TALLOC_FREE(array);
 578                         return ndr_map_error2ntstatus(ndr_err);
 579                 }
 580                 if (DEBUGLEVEL >= 10) {
 581                         DEBUG(10, ("notify_remove_onelevel:\n"));
 582                         NDR_PRINT_DEBUG(notify_entry_array, array);
 583                 }
 584         }
 585
 586         for (i=0; i<array->num_entries; i++) {
 587                 if ((private_data == array->entries[i].private_data) &&
 588                     cluster_id_equal(&notify->server,
 589                                      &array->entries[i].server)) {
 590                         break;
 591                 }
 592         }
 593
 594         if (i == array->num_entries) {
 595                 TALLOC_FREE(array);
 596                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 597         }
 598
 599         array->entries[i] = array->entries[array->num_entries-1];
 600         array->num_entries -= 1;
 601
 602         if (array->num_entries == 0) {
 603                 rec->delete_rec(rec);
 604                 TALLOC_FREE(array);
 605                 return NT_STATUS_OK;
 606         }
 607
 608         ndr_err = ndr_push_struct_blob(
 609                 &blob, rec, NULL, array,
 610                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 611         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 612                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 613                            ndr_errstr(ndr_err)));
 614                 TALLOC_FREE(array);
 615                 return ndr_map_error2ntstatus(ndr_err);
 616         }
 617
 618         if (DEBUGLEVEL >= 10) {
 619                 DEBUG(10, ("notify_add_onelevel:\n"));
 620                 NDR_PRINT_DEBUG(notify_entry_array, array);
 621         }
 622
 623         dbuf.dptr = blob.data;
 624         dbuf.dsize = blob.length;
 625
 626         status = rec->store(rec, dbuf, TDB_REPLACE);
 627         TALLOC_FREE(array);
 628         if (!NT_STATUS_IS_OK(status)) {
 629                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 630                            nt_errstr(status)));
 631                 return status;
 632         }
 633         return NT_STATUS_OK;
 634 }
 635
 636 /*
 637   remove a notify watch. Called when the directory handle is closed
 638 */
 639 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 640 {
 641         NTSTATUS status;
 642         struct notify_list *listel;
 643         int i, depth;
 644         struct notify_depth *d;
 645         struct db_record *rec;
 646
 647         /* see if change notify is enabled at all */
 648         if (notify == NULL) {
 649                 return NT_STATUS_NOT_IMPLEMENTED;
 650         }
 651
 652         for (listel=notify->list;listel;listel=listel->next) {
 653                 if (listel->private_data == private_data) {
 654                         DLIST_REMOVE(notify->list, listel);
 655                         break;
 656                 }
 657         }
 658         if (listel == NULL) {
 659                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 660         }
 661
 662         depth = listel->depth;
 663
 664         talloc_free(listel);
 665
 666         status = notify_fetch_locked(notify, &rec);
 667         NT_STATUS_NOT_OK_RETURN(status);
 668
 669         status = notify_load(notify, rec);
 670         if (!NT_STATUS_IS_OK(status)) {
 671                 talloc_free(rec);
 672                 return status;
 673         }
 674
 675         if (depth >= notify->array->num_depths) {
 676                 talloc_free(rec);
 677                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 678         }
 679
 680         /* we only have to search at the depth of this element */
 681         d = &notify->array->depth[depth];
 682
 683         for (i=0;i<d->num_entries;i++) {
 684                 if (private_data == d->entries[i].private_data &&
 685                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 686                         break;
 687                 }
 688         }
 689         if (i == d->num_entries) {
 690                 talloc_free(rec);
 691                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 692         }
 693
 694         if (i < d->num_entries-1) {
 695                 memmove(&d->entries[i], &d->entries[i+1],
 696                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 697         }
 698         d->num_entries--;
 699
 700         status = notify_save(notify, rec);
 701
 702         talloc_free(rec);
 703
 704         return status;
 705 }
 706
 707 /*
 708   remove all notify watches for a messaging server
 709 */
 710 static NTSTATUS notify_remove_all(struct notify_context *notify,
 711                                   const struct server_id *server)
 712 {
 713         NTSTATUS status;
 714         int i, depth, del_count=0;
 715         struct db_record *rec;
 716
 717         status = notify_fetch_locked(notify, &rec);
 718         NT_STATUS_NOT_OK_RETURN(status);
 719
 720         status = notify_load(notify, rec);
 721         if (!NT_STATUS_IS_OK(status)) {
 722                 talloc_free(rec);
 723                 return status;
 724         }
 725
 726         /* we have to search for all entries across all depths, looking for matches
 727            for the server id */
 728         for (depth=0;depth<notify->array->num_depths;depth++) {
 729                 struct notify_depth *d = &notify->array->depth[depth];
 730                 for (i=0;i<d->num_entries;i++) {
 731                         if (cluster_id_equal(server, &d->entries[i].server)) {
 732                                 if (i < d->num_entries-1) {
 733                                         memmove(&d->entries[i], &d->entries[i+1],
 734                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 735                                 }
 736                                 i--;
 737                                 d->num_entries--;
 738                                 del_count++;
 739                         }
 740                 }
 741         }
 742
 743         if (del_count > 0) {
 744                 status = notify_save(notify, rec);
 745         }
 746
 747         talloc_free(rec);
 748
 749         return status;
 750 }
 751
 752
 753 /*
 754   send a notify message to another messaging server
 755 */
 756 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 757                             const char *path, uint32_t action)
 758 {
 759         struct notify_event ev;
 760         DATA_BLOB data;
 761         NTSTATUS status;
 762         enum ndr_err_code ndr_err;
 763         TALLOC_CTX *tmp_ctx;
 764
 765         ev.action = action;
 766         ev.path = path;
 767         ev.private_data = e->private_data;
 768
 769         tmp_ctx = talloc_new(notify);
 770
 771         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, NULL, &ev,
 772                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 773         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 774                 talloc_free(tmp_ctx);
 775                 return ndr_map_error2ntstatus(ndr_err);
 776         }
 777
 778         status = messaging_send(notify->messaging_ctx, e->server,
 779                                 MSG_PVFS_NOTIFY, &data);
 780         talloc_free(tmp_ctx);
 781         return status;
 782 }
 783
 784 void notify_onelevel(struct notify_context *notify, uint32_t action,
 785                      uint32_t filter, struct file_id fid, const char *name)
 786 {
 787         struct notify_entry_array *array;
 788         TDB_DATA dbuf;
 789         DATA_BLOB blob;
 790         bool have_dead_entries = false;
 791         int i;
 792
 793         if (notify == NULL) {
 794                 return;
 795         }
 796
 797         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 798         if (array == NULL) {
 799                 return;
 800         }
 801
 802         if (notify->db_onelevel->fetch(
 803                     notify->db_onelevel, array,
 804                     make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 805                     &dbuf) == -1) {
 806                 TALLOC_FREE(array);
 807                 return;
 808         }
 809
 810         blob.data = (uint8 *)dbuf.dptr;
 811         blob.length = dbuf.dsize;
 812
 813         if (blob.length > 0) {
 814                 enum ndr_err_code ndr_err;
 815                 ndr_err = ndr_pull_struct_blob(
 816                         &blob, array, NULL, array,
 817                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 818                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 819                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 820                                    ndr_errstr(ndr_err)));
 821                         TALLOC_FREE(array);
 822                         return;
 823                 }
 824                 if (DEBUGLEVEL >= 10) {
 825                         DEBUG(10, ("notify_onelevel:\n"));
 826                         NDR_PRINT_DEBUG(notify_entry_array, array);
 827                 }
 828         }
 829
 830         for (i=0; i<array->num_entries; i++) {
 831                 struct notify_entry *e = &array->entries[i];
 832
 833                 if ((e->filter & filter) != 0) {
 834                         NTSTATUS status;
 835
 836                         status = notify_send(notify, e, name, action);
 837                         if (NT_STATUS_EQUAL(
 838                                     status, NT_STATUS_INVALID_HANDLE)) {
 839                                 /*
 840                                  * Mark the entry as dead. All entries have a
 841                                  * path set. The marker used here is setting
 842                                  * that to NULL.
 843                                  */
 844                                 e->path = NULL;
 845                                 have_dead_entries = true;
 846                         }
 847                 }
 848         }
 849
 850         if (!have_dead_entries) {
 851                 TALLOC_FREE(array);
 852                 return;
 853         }
 854
 855         for (i=0; i<array->num_entries; i++) {
 856                 struct notify_entry *e = &array->entries[i];
 857                 if (e->path != NULL) {
 858                         continue;
 859                 }
 860                 DEBUG(10, ("Deleting notify entries for process %s because "
 861                            "it's gone\n", procid_str_static(&e->server)));
 862                 /*
 863                  * Potential TODO: This might need optimizing,
 864                  * notify_remove_onelevel() does a fetch_locked() operation at
 865                  * every call. But this would only matter if a process with
 866                  * MANY notifies has died without shutting down properly.
 867                  */
 868                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 869         }
 870
 871         TALLOC_FREE(array);
 872         return;
 873 }
 874
 875 /*
 876   trigger a notify message for anyone waiting on a matching event
 877
 878   This function is called a lot, and needs to be very fast. The unusual data structure
 879   and traversal is designed to be fast in the average case, even for large numbers of
 880   notifies
 881 */
 882 void notify_trigger(struct notify_context *notify,
 883                     uint32_t action, uint32_t filter, const char *path)
 884 {
 885         NTSTATUS status;
 886         int depth;
 887         const char *p, *next_p;
 888
 889         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 890                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 891
 892         /* see if change notify is enabled at all */
 893         if (notify == NULL) {
 894                 return;
 895         }
 896
 897  again:
 898         status = notify_load(notify, NULL);
 899         if (!NT_STATUS_IS_OK(status)) {
 900                 return;
 901         }
 902
 903         /* loop along the given path, working with each directory depth separately */
 904         for (depth=0,p=path;
 905              p && depth < notify->array->num_depths;
 906              p=next_p,depth++) {
 907                 int p_len = p - path;
 908                 int min_i, max_i, i;
 909                 struct notify_depth *d = &notify->array->depth[depth];
 910                 next_p = strchr(p+1, '/');
 911
 912                 /* see if there are any entries at this depth */
 913                 if (d->num_entries == 0) continue;
 914
 915                 /* try to skip based on the maximum mask. If next_p is
 916                  NULL then we know it will be a 'this directory'
 917                  match, otherwise it must be a subdir match */
 918                 if (next_p != NULL) {
 919                         if (0 == (filter & d->max_mask_subdir)) {
 920                                 continue;
 921                         }
 922                 } else {
 923                         if (0 == (filter & d->max_mask)) {
 924                                 continue;
 925                         }
 926                 }
 927
 928                 /* we know there is an entry here worth looking
 929                  for. Use a bisection search to find the first entry
 930                  with a matching path */
 931                 min_i = 0;
 932                 max_i = d->num_entries-1;
 933
 934                 while (min_i < max_i) {
 935                         struct notify_entry *e;
 936                         int cmp;
 937                         i = (min_i+max_i)/2;
 938                         e = &d->entries[i];
 939                         cmp = strncmp(path, e->path, p_len);
 940                         if (cmp == 0) {
 941                                 if (p_len == e->path_len) {
 942                                         max_i = i;
 943                                 } else {
 944                                         max_i = i-1;
 945                                 }
 946                         } else if (cmp < 0) {
 947                                 max_i = i-1;
 948                         } else {
 949                                 min_i = i+1;
 950                         }
 951                 }
 952
 953                 if (min_i != max_i) {
 954                         /* none match */
 955                         continue;
 956                 }
 957
 958                 /* we now know that the entries start at min_i */
 959                 for (i=min_i;i<d->num_entries;i++) {
 960                         struct notify_entry *e = &d->entries[i];
 961                         if (p_len != e->path_len ||
 962                             strncmp(path, e->path, p_len) != 0) break;
 963                         if (next_p != NULL) {
 964                                 if (0 == (filter & e->subdir_filter)) {
 965                                         continue;
 966                                 }
 967                         } else {
 968                                 if (0 == (filter & e->filter)) {
 969                                         continue;
 970                                 }
 971                         }
 972                         status = notify_send(notify, e, path + e->path_len + 1,
 973                                              action);
 974
 975                         if (NT_STATUS_EQUAL(
 976                                     status, NT_STATUS_INVALID_HANDLE)) {
 977                                 struct server_id server = e->server;
 978
 979                                 DEBUG(10, ("Deleting notify entries for "
 980                                            "process %s because it's gone\n",
 981                                            procid_str_static(&e->server)));
 982                                 notify_remove_all(notify, &server);
 983                                 goto again;
 984                         }
 985                 }
 986         }
 987 }