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 "system/filesys.h"
  28 #include "librpc/gen_ndr/ndr_notify.h"
  29 #include "dbwrap.h"
  30 #include "smbd/smbd.h"
  31 #include "messages.h"
  32 #include "lib/util/tdb_wrap.h"
  33
  34 struct notify_context {
  35         struct db_context *db_recursive;
  36         struct db_context *db_onelevel;
  37         struct server_id server;
  38         struct messaging_context *messaging_ctx;
  39         struct notify_list *list;
  40         struct notify_array *array;
  41         int seqnum;
  42         struct sys_notify_context *sys_notify_ctx;
  43         TDB_DATA key;
  44 };
  45
  46
  47 struct notify_list {
  48         struct notify_list *next, *prev;
  49         void *private_data;
  50         void (*callback)(void *, const struct notify_event *);
  51         void *sys_notify_handle;
  52         int depth;
  53 };
  54
  55 #define NOTIFY_KEY "notify array"
  56
  57 #define NOTIFY_ENABLE           "notify:enable"
  58 #define NOTIFY_ENABLE_DEFAULT   True
  59
  60 static NTSTATUS notify_remove_all(struct notify_context *notify,
  61                                   const struct server_id *server);
  62 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
  63                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
  64
  65 /*
  66   destroy the notify context
  67 */
  68 static int notify_destructor(struct notify_context *notify)
  69 {
  70         messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
  71
  72         if (notify->list != NULL) {
  73                 notify_remove_all(notify, &notify->server);
  74         }
  75
  76         return 0;
  77 }
  78
  79 /*
  80   Open up the notify.tdb database. You should close it down using
  81   talloc_free(). We need the messaging_ctx to allow for notifications
  82   via internal messages
  83 */
  84 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
  85                                    struct messaging_context *messaging_ctx,
  86                                    struct event_context *ev,
  87                                    connection_struct *conn)
  88 {
  89         struct notify_context *notify;
  90
  91         if (!lp_change_notify(conn->params)) {
  92                 return NULL;
  93         }
  94
  95         notify = talloc(mem_ctx, struct notify_context);
  96         if (notify == NULL) {
  97                 return NULL;
  98         }
  99
 100         notify->db_recursive = db_open(notify, lock_path("notify.tdb"),
 101                                        0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 102                                        O_RDWR|O_CREAT, 0644);
 103         if (notify->db_recursive == NULL) {
 104                 talloc_free(notify);
 105                 return NULL;
 106         }
 107
 108         notify->db_onelevel = db_open(notify, lock_path("notify_onelevel.tdb"),
 109                                       0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 110                                       O_RDWR|O_CREAT, 0644);
 111         if (notify->db_onelevel == NULL) {
 112                 talloc_free(notify);
 113                 return NULL;
 114         }
 115
 116         notify->server = server;
 117         notify->messaging_ctx = messaging_ctx;
 118         notify->list = NULL;
 119         notify->array = NULL;
 120         notify->seqnum = notify->db_recursive->get_seqnum(
 121                 notify->db_recursive);
 122         notify->key = string_term_tdb_data(NOTIFY_KEY);
 123
 124         talloc_set_destructor(notify, notify_destructor);
 125
 126         /* register with the messaging subsystem for the notify
 127            message type */
 128         messaging_register(notify->messaging_ctx, notify,
 129                            MSG_PVFS_NOTIFY, notify_handler);
 130
 131         notify->sys_notify_ctx = sys_notify_context_create(conn, notify, ev);
 132
 133         return notify;
 134 }
 135
 136 bool notify_internal_parent_init(TALLOC_CTX *mem_ctx)
 137 {
 138         struct tdb_wrap *db1, *db2;
 139
 140         if (lp_clustering()) {
 141                 return true;
 142         }
 143
 144         /*
 145          * Open the tdbs in the parent process (smbd) so that our
 146          * CLEAR_IF_FIRST optimization in tdb_reopen_all can properly
 147          * work.
 148          */
 149
 150         db1 = tdb_wrap_open(mem_ctx, lock_path("notify.tdb"),
 151                             0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 152                            O_RDWR|O_CREAT, 0644);
 153         if (db1 == NULL) {
 154                 DEBUG(1, ("could not open notify.tdb: %s\n", strerror(errno)));
 155                 return false;
 156         }
 157         db2 = tdb_wrap_open(mem_ctx, lock_path("notify_onelevel.tdb"),
 158                             0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDWR|O_CREAT, 0644);
 159         if (db2 == NULL) {
 160                 DEBUG(1, ("could not open notify_onelevel.tdb: %s\n",
 161                           strerror(errno)));
 162                 TALLOC_FREE(db1);
 163                 return false;
 164         }
 165         return true;
 166 }
 167
 168 /*
 169   lock and fetch the record
 170 */
 171 static NTSTATUS notify_fetch_locked(struct notify_context *notify, struct db_record **rec)
 172 {
 173         *rec = notify->db_recursive->fetch_locked(notify->db_recursive,
 174                                                   notify, notify->key);
 175         if (*rec == NULL) {
 176                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 177         }
 178         return NT_STATUS_OK;
 179 }
 180
 181 /*
 182   load the notify array
 183 */
 184 static NTSTATUS notify_load(struct notify_context *notify, struct db_record *rec)
 185 {
 186         TDB_DATA dbuf;
 187         DATA_BLOB blob;
 188         NTSTATUS status;
 189         int seqnum;
 190
 191         seqnum = notify->db_recursive->get_seqnum(notify->db_recursive);
 192
 193         if (seqnum == notify->seqnum && notify->array != NULL) {
 194                 return NT_STATUS_OK;
 195         }
 196
 197         notify->seqnum = seqnum;
 198
 199         talloc_free(notify->array);
 200         notify->array = TALLOC_ZERO_P(notify, struct notify_array);
 201         NT_STATUS_HAVE_NO_MEMORY(notify->array);
 202
 203         if (!rec) {
 204                 if (notify->db_recursive->fetch(notify->db_recursive, notify,
 205                                                 notify->key, &dbuf) != 0) {
 206                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 207                 }
 208         } else {
 209                 dbuf = rec->value;
 210         }
 211
 212         blob.data = (uint8 *)dbuf.dptr;
 213         blob.length = dbuf.dsize;
 214
 215         status = NT_STATUS_OK;
 216         if (blob.length > 0) {
 217                 enum ndr_err_code ndr_err;
 218                 ndr_err = ndr_pull_struct_blob(&blob, notify->array, notify->array,
 219                                                (ndr_pull_flags_fn_t)ndr_pull_notify_array);
 220                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 221                         /* 1. log that we got a corrupt notify_array
 222                          * 2. clear the variable the garbage was stored into to not trip
 223                          *  over it next time this method is entered with the same seqnum
 224                          * 3. delete it from the database */
 225                         DEBUG(2, ("notify_array is corrupt, discarding it\n"));
 226
 227                         ZERO_STRUCTP(notify->array);
 228                         if (rec != NULL) {
 229                                 rec->delete_rec(rec);
 230                         }
 231
 232                 } else {
 233                         if (DEBUGLEVEL >= 10) {
 234                                 DEBUG(10, ("notify_load:\n"));
 235                                 NDR_PRINT_DEBUG(notify_array, notify->array);
 236                         }
 237                 }
 238         }
 239
 240
 241         if (!rec) {
 242                 talloc_free(dbuf.dptr);
 243         }
 244
 245         return status;
 246 }
 247
 248 /*
 249   compare notify entries for sorting
 250 */
 251 static int notify_compare(const struct notify_entry *e1, const struct notify_entry *e2)
 252 {
 253         return strcmp(e1->path, e2->path);
 254 }
 255
 256 /*
 257   save the notify array
 258 */
 259 static NTSTATUS notify_save(struct notify_context *notify, struct db_record *rec)
 260 {
 261         TDB_DATA dbuf;
 262         DATA_BLOB blob;
 263         NTSTATUS status;
 264         enum ndr_err_code ndr_err;
 265         TALLOC_CTX *tmp_ctx;
 266
 267         /* if possible, remove some depth arrays */
 268         while (notify->array->num_depths > 0 &&
 269                notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
 270                 notify->array->num_depths--;
 271         }
 272
 273         /* we might just be able to delete the record */
 274         if (notify->array->num_depths == 0) {
 275                 return rec->delete_rec(rec);
 276         }
 277
 278         tmp_ctx = talloc_new(notify);
 279         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 280
 281         ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, notify->array,
 282                                       (ndr_push_flags_fn_t)ndr_push_notify_array);
 283         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 284                 talloc_free(tmp_ctx);
 285                 return ndr_map_error2ntstatus(ndr_err);
 286         }
 287
 288         if (DEBUGLEVEL >= 10) {
 289                 DEBUG(10, ("notify_save:\n"));
 290                 NDR_PRINT_DEBUG(notify_array, notify->array);
 291         }
 292
 293         dbuf.dptr = blob.data;
 294         dbuf.dsize = blob.length;
 295
 296         status = rec->store(rec, dbuf, TDB_REPLACE);
 297         talloc_free(tmp_ctx);
 298
 299         return status;
 300 }
 301
 302
 303 /*
 304   handle incoming notify messages
 305 */
 306 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
 307                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
 308 {
 309         struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
 310         enum ndr_err_code ndr_err;
 311         struct notify_event ev;
 312         TALLOC_CTX *tmp_ctx = talloc_new(notify);
 313         struct notify_list *listel;
 314
 315         if (tmp_ctx == NULL) {
 316                 return;
 317         }
 318
 319         ndr_err = ndr_pull_struct_blob(data, tmp_ctx, &ev,
 320                                        (ndr_pull_flags_fn_t)ndr_pull_notify_event);
 321         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 322                 talloc_free(tmp_ctx);
 323                 return;
 324         }
 325
 326         for (listel=notify->list;listel;listel=listel->next) {
 327                 if (listel->private_data == ev.private_data) {
 328                         listel->callback(listel->private_data, &ev);
 329                         break;
 330                 }
 331         }
 332
 333         talloc_free(tmp_ctx);
 334 }
 335
 336 /*
 337   callback from sys_notify telling us about changes from the OS
 338 */
 339 static void sys_notify_callback(struct sys_notify_context *ctx,
 340                                 void *ptr, struct notify_event *ev)
 341 {
 342         struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
 343         ev->private_data = listel;
 344         DEBUG(10, ("sys_notify_callback called with action=%d, for %s\n",
 345                    ev->action, ev->path));
 346         listel->callback(listel->private_data, ev);
 347 }
 348
 349 /*
 350   add an entry to the notify array
 351 */
 352 static NTSTATUS notify_add_array(struct notify_context *notify, struct db_record *rec,
 353                                  struct notify_entry *e,
 354                                  void *private_data, int depth)
 355 {
 356         int i;
 357         struct notify_depth *d;
 358         struct notify_entry *ee;
 359
 360         /* possibly expand the depths array */
 361         if (depth >= notify->array->num_depths) {
 362                 d = talloc_realloc(notify->array, notify->array->depth,
 363                                    struct notify_depth, depth+1);
 364                 NT_STATUS_HAVE_NO_MEMORY(d);
 365                 for (i=notify->array->num_depths;i<=depth;i++) {
 366                         ZERO_STRUCT(d[i]);
 367                 }
 368                 notify->array->depth = d;
 369                 notify->array->num_depths = depth+1;
 370         }
 371         d = &notify->array->depth[depth];
 372
 373         /* expand the entries array */
 374         ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
 375                             d->num_entries+1);
 376         NT_STATUS_HAVE_NO_MEMORY(ee);
 377         d->entries = ee;
 378
 379         d->entries[d->num_entries] = *e;
 380         d->entries[d->num_entries].private_data = private_data;
 381         d->entries[d->num_entries].server = notify->server;
 382         d->entries[d->num_entries].path_len = strlen(e->path);
 383         d->num_entries++;
 384
 385         d->max_mask |= e->filter;
 386         d->max_mask_subdir |= e->subdir_filter;
 387
 388         TYPESAFE_QSORT(d->entries, d->num_entries, notify_compare);
 389
 390         /* recalculate the maximum masks */
 391         d->max_mask = 0;
 392         d->max_mask_subdir = 0;
 393
 394         for (i=0;i<d->num_entries;i++) {
 395                 d->max_mask |= d->entries[i].filter;
 396                 d->max_mask_subdir |= d->entries[i].subdir_filter;
 397         }
 398
 399         return notify_save(notify, rec);
 400 }
 401
 402 /*
 403   Add a non-recursive watch
 404 */
 405
 406 static void notify_add_onelevel(struct notify_context *notify,
 407                                 struct notify_entry *e, void *private_data)
 408 {
 409         struct notify_entry_array *array;
 410         struct db_record *rec;
 411         DATA_BLOB blob;
 412         TDB_DATA dbuf;
 413         enum ndr_err_code ndr_err;
 414         NTSTATUS status;
 415
 416         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 417         if (array == NULL) {
 418                 return;
 419         }
 420
 421         rec = notify->db_onelevel->fetch_locked(
 422                 notify->db_onelevel, talloc_tos(),
 423                 make_tdb_data((uint8_t *)&e->dir_id, sizeof(e->dir_id)));
 424         if (rec == NULL) {
 425                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 426                            "\n", file_id_string_tos(&e->dir_id)));
 427                 TALLOC_FREE(array);
 428                 return;
 429         }
 430
 431         blob.data = (uint8_t *)rec->value.dptr;
 432         blob.length = rec->value.dsize;
 433
 434         if (blob.length > 0) {
 435                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 436                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 437                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 438                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 439                                    ndr_errstr(ndr_err)));
 440                         TALLOC_FREE(array);
 441                         return;
 442                 }
 443                 if (DEBUGLEVEL >= 10) {
 444                         DEBUG(10, ("notify_add_onelevel:\n"));
 445                         NDR_PRINT_DEBUG(notify_entry_array, array);
 446                 }
 447         }
 448
 449         array->entries = talloc_realloc(array, array->entries,
 450                                         struct notify_entry,
 451                                         array->num_entries+1);
 452         if (array->entries == NULL) {
 453                 TALLOC_FREE(array);
 454                 return;
 455         }
 456         array->entries[array->num_entries] = *e;
 457         array->entries[array->num_entries].private_data = private_data;
 458         array->entries[array->num_entries].server = notify->server;
 459         array->num_entries += 1;
 460
 461         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 462                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 463         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 464                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 465                            ndr_errstr(ndr_err)));
 466                 TALLOC_FREE(array);
 467                 return;
 468         }
 469
 470         if (DEBUGLEVEL >= 10) {
 471                 DEBUG(10, ("notify_add_onelevel:\n"));
 472                 NDR_PRINT_DEBUG(notify_entry_array, array);
 473         }
 474
 475         dbuf.dptr = blob.data;
 476         dbuf.dsize = blob.length;
 477
 478         status = rec->store(rec, dbuf, TDB_REPLACE);
 479         TALLOC_FREE(array);
 480         if (!NT_STATUS_IS_OK(status)) {
 481                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 482                            nt_errstr(status)));
 483                 return;
 484         }
 485         e->filter = 0;
 486         return;
 487 }
 488
 489
 490 /*
 491   add a notify watch. This is called when a notify is first setup on a open
 492   directory handle.
 493 */
 494 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 495                     void (*callback)(void *, const struct notify_event *),
 496                     void *private_data)
 497 {
 498         struct notify_entry e = *e0;
 499         NTSTATUS status;
 500         char *tmp_path = NULL;
 501         struct notify_list *listel;
 502         size_t len;
 503         int depth;
 504         struct db_record *rec;
 505
 506         /* see if change notify is enabled at all */
 507         if (notify == NULL) {
 508                 return NT_STATUS_NOT_IMPLEMENTED;
 509         }
 510
 511         status = notify_fetch_locked(notify, &rec);
 512         NT_STATUS_NOT_OK_RETURN(status);
 513
 514         status = notify_load(notify, rec);
 515         if (!NT_STATUS_IS_OK(status)) {
 516                 talloc_free(rec);
 517                 return status;
 518         }
 519
 520         /* cope with /. on the end of the path */
 521         len = strlen(e.path);
 522         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 523                 tmp_path = talloc_strndup(notify, e.path, len-2);
 524                 if (tmp_path == NULL) {
 525                         status = NT_STATUS_NO_MEMORY;
 526                         goto done;
 527                 }
 528                 e.path = tmp_path;
 529         }
 530
 531         depth = count_chars(e.path, '/');
 532
 533         listel = TALLOC_ZERO_P(notify, struct notify_list);
 534         if (listel == NULL) {
 535                 status = NT_STATUS_NO_MEMORY;
 536                 goto done;
 537         }
 538
 539         listel->private_data = private_data;
 540         listel->callback = callback;
 541         listel->depth = depth;
 542         DLIST_ADD(notify->list, listel);
 543
 544         /* ignore failures from sys_notify */
 545         if (notify->sys_notify_ctx != NULL) {
 546                 /*
 547                   this call will modify e.filter and e.subdir_filter
 548                   to remove bits handled by the backend
 549                 */
 550                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 551                                           sys_notify_callback, listel,
 552                                           &listel->sys_notify_handle);
 553                 if (NT_STATUS_IS_OK(status)) {
 554                         talloc_steal(listel, listel->sys_notify_handle);
 555                 }
 556         }
 557
 558         if (e.filter != 0) {
 559                 notify_add_onelevel(notify, &e, private_data);
 560                 status = NT_STATUS_OK;
 561         }
 562
 563         /* if the system notify handler couldn't handle some of the
 564            filter bits, or couldn't handle a request for recursion
 565            then we need to install it in the array used for the
 566            intra-samba notify handling */
 567         if (e.filter != 0 || e.subdir_filter != 0) {
 568                 status = notify_add_array(notify, rec, &e, private_data, depth);
 569         }
 570
 571 done:
 572         talloc_free(rec);
 573         talloc_free(tmp_path);
 574
 575         return status;
 576 }
 577
 578 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 579                                 const struct file_id *fid,
 580                                 void *private_data)
 581 {
 582         struct notify_entry_array *array;
 583         struct db_record *rec;
 584         DATA_BLOB blob;
 585         TDB_DATA dbuf;
 586         enum ndr_err_code ndr_err;
 587         NTSTATUS status;
 588         int i;
 589
 590         if (notify == NULL) {
 591                 return NT_STATUS_NOT_IMPLEMENTED;
 592         }
 593
 594         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 595         if (array == NULL) {
 596                 return NT_STATUS_NO_MEMORY;
 597         }
 598
 599         rec = notify->db_onelevel->fetch_locked(
 600                 notify->db_onelevel, array,
 601                 make_tdb_data((const uint8_t *)fid, sizeof(*fid)));
 602         if (rec == NULL) {
 603                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 604                            "\n", file_id_string_tos(fid)));
 605                 TALLOC_FREE(array);
 606                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 607         }
 608
 609         blob.data = (uint8_t *)rec->value.dptr;
 610         blob.length = rec->value.dsize;
 611
 612         if (blob.length > 0) {
 613                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 614                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 615                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 616                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 617                                    ndr_errstr(ndr_err)));
 618                         TALLOC_FREE(array);
 619                         return ndr_map_error2ntstatus(ndr_err);
 620                 }
 621                 if (DEBUGLEVEL >= 10) {
 622                         DEBUG(10, ("notify_remove_onelevel:\n"));
 623                         NDR_PRINT_DEBUG(notify_entry_array, array);
 624                 }
 625         }
 626
 627         for (i=0; i<array->num_entries; i++) {
 628                 if ((private_data == array->entries[i].private_data) &&
 629                     cluster_id_equal(&notify->server,
 630                                      &array->entries[i].server)) {
 631                         break;
 632                 }
 633         }
 634
 635         if (i == array->num_entries) {
 636                 TALLOC_FREE(array);
 637                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 638         }
 639
 640         array->entries[i] = array->entries[array->num_entries-1];
 641         array->num_entries -= 1;
 642
 643         if (array->num_entries == 0) {
 644                 rec->delete_rec(rec);
 645                 TALLOC_FREE(array);
 646                 return NT_STATUS_OK;
 647         }
 648
 649         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 650                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 651         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 652                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 653                            ndr_errstr(ndr_err)));
 654                 TALLOC_FREE(array);
 655                 return ndr_map_error2ntstatus(ndr_err);
 656         }
 657
 658         if (DEBUGLEVEL >= 10) {
 659                 DEBUG(10, ("notify_add_onelevel:\n"));
 660                 NDR_PRINT_DEBUG(notify_entry_array, array);
 661         }
 662
 663         dbuf.dptr = blob.data;
 664         dbuf.dsize = blob.length;
 665
 666         status = rec->store(rec, dbuf, TDB_REPLACE);
 667         TALLOC_FREE(array);
 668         if (!NT_STATUS_IS_OK(status)) {
 669                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 670                            nt_errstr(status)));
 671                 return status;
 672         }
 673         return NT_STATUS_OK;
 674 }
 675
 676 /*
 677   remove a notify watch. Called when the directory handle is closed
 678 */
 679 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 680 {
 681         NTSTATUS status;
 682         struct notify_list *listel;
 683         int i, depth;
 684         struct notify_depth *d;
 685         struct db_record *rec;
 686
 687         /* see if change notify is enabled at all */
 688         if (notify == NULL) {
 689                 return NT_STATUS_NOT_IMPLEMENTED;
 690         }
 691
 692         for (listel=notify->list;listel;listel=listel->next) {
 693                 if (listel->private_data == private_data) {
 694                         DLIST_REMOVE(notify->list, listel);
 695                         break;
 696                 }
 697         }
 698         if (listel == NULL) {
 699                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 700         }
 701
 702         depth = listel->depth;
 703
 704         talloc_free(listel);
 705
 706         status = notify_fetch_locked(notify, &rec);
 707         NT_STATUS_NOT_OK_RETURN(status);
 708
 709         status = notify_load(notify, rec);
 710         if (!NT_STATUS_IS_OK(status)) {
 711                 talloc_free(rec);
 712                 return status;
 713         }
 714
 715         if (depth >= notify->array->num_depths) {
 716                 talloc_free(rec);
 717                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 718         }
 719
 720         /* we only have to search at the depth of this element */
 721         d = &notify->array->depth[depth];
 722
 723         for (i=0;i<d->num_entries;i++) {
 724                 if (private_data == d->entries[i].private_data &&
 725                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 726                         break;
 727                 }
 728         }
 729         if (i == d->num_entries) {
 730                 talloc_free(rec);
 731                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 732         }
 733
 734         if (i < d->num_entries-1) {
 735                 memmove(&d->entries[i], &d->entries[i+1],
 736                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 737         }
 738         d->num_entries--;
 739
 740         status = notify_save(notify, rec);
 741
 742         talloc_free(rec);
 743
 744         return status;
 745 }
 746
 747 /*
 748   remove all notify watches for a messaging server
 749 */
 750 static NTSTATUS notify_remove_all(struct notify_context *notify,
 751                                   const struct server_id *server)
 752 {
 753         NTSTATUS status;
 754         int i, depth, del_count=0;
 755         struct db_record *rec;
 756
 757         status = notify_fetch_locked(notify, &rec);
 758         NT_STATUS_NOT_OK_RETURN(status);
 759
 760         status = notify_load(notify, rec);
 761         if (!NT_STATUS_IS_OK(status)) {
 762                 talloc_free(rec);
 763                 return status;
 764         }
 765
 766         /* we have to search for all entries across all depths, looking for matches
 767            for the server id */
 768         for (depth=0;depth<notify->array->num_depths;depth++) {
 769                 struct notify_depth *d = &notify->array->depth[depth];
 770                 for (i=0;i<d->num_entries;i++) {
 771                         if (cluster_id_equal(server, &d->entries[i].server)) {
 772                                 if (i < d->num_entries-1) {
 773                                         memmove(&d->entries[i], &d->entries[i+1],
 774                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 775                                 }
 776                                 i--;
 777                                 d->num_entries--;
 778                                 del_count++;
 779                         }
 780                 }
 781         }
 782
 783         if (del_count > 0) {
 784                 status = notify_save(notify, rec);
 785         }
 786
 787         talloc_free(rec);
 788
 789         return status;
 790 }
 791
 792
 793 /*
 794   send a notify message to another messaging server
 795 */
 796 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 797                             const char *path, uint32_t action)
 798 {
 799         struct notify_event ev;
 800         DATA_BLOB data;
 801         NTSTATUS status;
 802         enum ndr_err_code ndr_err;
 803         TALLOC_CTX *tmp_ctx;
 804
 805         ev.action = action;
 806         ev.path = path;
 807         ev.private_data = e->private_data;
 808
 809         tmp_ctx = talloc_new(notify);
 810
 811         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, &ev,
 812                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 813         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 814                 talloc_free(tmp_ctx);
 815                 return ndr_map_error2ntstatus(ndr_err);
 816         }
 817
 818         status = messaging_send(notify->messaging_ctx, e->server,
 819                                 MSG_PVFS_NOTIFY, &data);
 820         talloc_free(tmp_ctx);
 821         return status;
 822 }
 823
 824 void notify_onelevel(struct notify_context *notify, uint32_t action,
 825                      uint32_t filter, struct file_id fid, const char *name)
 826 {
 827         struct notify_entry_array *array;
 828         TDB_DATA dbuf;
 829         DATA_BLOB blob;
 830         bool have_dead_entries = false;
 831         int i;
 832
 833         if (notify == NULL) {
 834                 return;
 835         }
 836
 837         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 838         if (array == NULL) {
 839                 return;
 840         }
 841
 842         if (notify->db_onelevel->fetch(
 843                     notify->db_onelevel, array,
 844                     make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 845                     &dbuf) == -1) {
 846                 TALLOC_FREE(array);
 847                 return;
 848         }
 849
 850         blob.data = (uint8 *)dbuf.dptr;
 851         blob.length = dbuf.dsize;
 852
 853         if (blob.length > 0) {
 854                 enum ndr_err_code ndr_err;
 855                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 856                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 857                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 858                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 859                                    ndr_errstr(ndr_err)));
 860                         TALLOC_FREE(array);
 861                         return;
 862                 }
 863                 if (DEBUGLEVEL >= 10) {
 864                         DEBUG(10, ("notify_onelevel:\n"));
 865                         NDR_PRINT_DEBUG(notify_entry_array, array);
 866                 }
 867         }
 868
 869         for (i=0; i<array->num_entries; i++) {
 870                 struct notify_entry *e = &array->entries[i];
 871
 872                 if ((e->filter & filter) != 0) {
 873                         NTSTATUS status;
 874
 875                         status = notify_send(notify, e, name, action);
 876                         if (NT_STATUS_EQUAL(
 877                                     status, NT_STATUS_INVALID_HANDLE)) {
 878                                 /*
 879                                  * Mark the entry as dead. All entries have a
 880                                  * path set. The marker used here is setting
 881                                  * that to NULL.
 882                                  */
 883                                 e->path = NULL;
 884                                 have_dead_entries = true;
 885                         }
 886                 }
 887         }
 888
 889         if (!have_dead_entries) {
 890                 TALLOC_FREE(array);
 891                 return;
 892         }
 893
 894         for (i=0; i<array->num_entries; i++) {
 895                 struct notify_entry *e = &array->entries[i];
 896                 if (e->path != NULL) {
 897                         continue;
 898                 }
 899                 DEBUG(10, ("Deleting notify entries for process %s because "
 900                            "it's gone\n", procid_str_static(&e->server)));
 901                 /*
 902                  * Potential TODO: This might need optimizing,
 903                  * notify_remove_onelevel() does a fetch_locked() operation at
 904                  * every call. But this would only matter if a process with
 905                  * MANY notifies has died without shutting down properly.
 906                  */
 907                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 908         }
 909
 910         TALLOC_FREE(array);
 911         return;
 912 }
 913
 914 /*
 915   trigger a notify message for anyone waiting on a matching event
 916
 917   This function is called a lot, and needs to be very fast. The unusual data structure
 918   and traversal is designed to be fast in the average case, even for large numbers of
 919   notifies
 920 */
 921 void notify_trigger(struct notify_context *notify,
 922                     uint32_t action, uint32_t filter, const char *path)
 923 {
 924         NTSTATUS status;
 925         int depth;
 926         const char *p, *next_p;
 927
 928         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 929                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 930
 931         /* see if change notify is enabled at all */
 932         if (notify == NULL) {
 933                 return;
 934         }
 935
 936  again:
 937         status = notify_load(notify, NULL);
 938         if (!NT_STATUS_IS_OK(status)) {
 939                 return;
 940         }
 941
 942         /* loop along the given path, working with each directory depth separately */
 943         for (depth=0,p=path;
 944              p && depth < notify->array->num_depths;
 945              p=next_p,depth++) {
 946                 int p_len = p - path;
 947                 int min_i, max_i, i;
 948                 struct notify_depth *d = &notify->array->depth[depth];
 949                 next_p = strchr(p+1, '/');
 950
 951                 /* see if there are any entries at this depth */
 952                 if (d->num_entries == 0) continue;
 953
 954                 /* try to skip based on the maximum mask. If next_p is
 955                  NULL then we know it will be a 'this directory'
 956                  match, otherwise it must be a subdir match */
 957                 if (next_p != NULL) {
 958                         if (0 == (filter & d->max_mask_subdir)) {
 959                                 continue;
 960                         }
 961                 } else {
 962                         if (0 == (filter & d->max_mask)) {
 963                                 continue;
 964                         }
 965                 }
 966
 967                 /* we know there is an entry here worth looking
 968                  for. Use a bisection search to find the first entry
 969                  with a matching path */
 970                 min_i = 0;
 971                 max_i = d->num_entries-1;
 972
 973                 while (min_i < max_i) {
 974                         struct notify_entry *e;
 975                         int cmp;
 976                         i = (min_i+max_i)/2;
 977                         e = &d->entries[i];
 978                         cmp = strncmp(path, e->path, p_len);
 979                         if (cmp == 0) {
 980                                 if (p_len == e->path_len) {
 981                                         max_i = i;
 982                                 } else {
 983                                         max_i = i-1;
 984                                 }
 985                         } else if (cmp < 0) {
 986                                 max_i = i-1;
 987                         } else {
 988                                 min_i = i+1;
 989                         }
 990                 }
 991
 992                 if (min_i != max_i) {
 993                         /* none match */
 994                         continue;
 995                 }
 996
 997                 /* we now know that the entries start at min_i */
 998                 for (i=min_i;i<d->num_entries;i++) {
 999                         struct notify_entry *e = &d->entries[i];
1000                         if (p_len != e->path_len ||
1001                             strncmp(path, e->path, p_len) != 0) break;
1002                         if (next_p != NULL) {
1003                                 if (0 == (filter & e->subdir_filter)) {
1004                                         continue;
1005                                 }
1006                         } else {
1007                                 if (0 == (filter & e->filter)) {
1008                                         continue;
1009                                 }
1010                         }
1011                         status = notify_send(notify, e, path + e->path_len + 1,
1012                                              action);
1013
1014                         if (NT_STATUS_EQUAL(
1015                                     status, NT_STATUS_INVALID_HANDLE)) {
1016                                 struct server_id server = e->server;
1017
1018                                 DEBUG(10, ("Deleting notify entries for "
1019                                            "process %s because it's gone\n",
1020                                            procid_str_static(&e->server)));
1021                                 notify_remove_all(notify, &server);
1022                                 goto again;
1023                         }
1024                 }
1025         }
1026 }