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_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 struct notify_entry *e1, const struct notify_entry *e2)
 204 {
 205         return strcmp(e1->path, e2->path);
 206 }
 207
 208 /*
 209   save the notify array
 210 */
 211 static NTSTATUS notify_save(struct notify_context *notify, struct db_record *rec)
 212 {
 213         TDB_DATA dbuf;
 214         DATA_BLOB blob;
 215         NTSTATUS status;
 216         enum ndr_err_code ndr_err;
 217         TALLOC_CTX *tmp_ctx;
 218
 219         /* if possible, remove some depth arrays */
 220         while (notify->array->num_depths > 0 &&
 221                notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
 222                 notify->array->num_depths--;
 223         }
 224
 225         /* we might just be able to delete the record */
 226         if (notify->array->num_depths == 0) {
 227                 return rec->delete_rec(rec);
 228         }
 229
 230         tmp_ctx = talloc_new(notify);
 231         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 232
 233         ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, NULL, notify->array,
 234                                       (ndr_push_flags_fn_t)ndr_push_notify_array);
 235         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 236                 talloc_free(tmp_ctx);
 237                 return ndr_map_error2ntstatus(ndr_err);
 238         }
 239
 240         if (DEBUGLEVEL >= 10) {
 241                 DEBUG(10, ("notify_save:\n"));
 242                 NDR_PRINT_DEBUG(notify_array, notify->array);
 243         }
 244
 245         dbuf.dptr = blob.data;
 246         dbuf.dsize = blob.length;
 247
 248         status = rec->store(rec, dbuf, TDB_REPLACE);
 249         talloc_free(tmp_ctx);
 250
 251         return status;
 252 }
 253
 254
 255 /*
 256   handle incoming notify messages
 257 */
 258 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
 259                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
 260 {
 261         struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
 262         enum ndr_err_code ndr_err;
 263         struct notify_event ev;
 264         TALLOC_CTX *tmp_ctx = talloc_new(notify);
 265         struct notify_list *listel;
 266
 267         if (tmp_ctx == NULL) {
 268                 return;
 269         }
 270
 271         ndr_err = ndr_pull_struct_blob(data, tmp_ctx, NULL, &ev,
 272                                        (ndr_pull_flags_fn_t)ndr_pull_notify_event);
 273         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 274                 talloc_free(tmp_ctx);
 275                 return;
 276         }
 277
 278         for (listel=notify->list;listel;listel=listel->next) {
 279                 if (listel->private_data == ev.private_data) {
 280                         listel->callback(listel->private_data, &ev);
 281                         break;
 282                 }
 283         }
 284
 285         talloc_free(tmp_ctx);
 286 }
 287
 288 /*
 289   callback from sys_notify telling us about changes from the OS
 290 */
 291 static void sys_notify_callback(struct sys_notify_context *ctx,
 292                                 void *ptr, struct notify_event *ev)
 293 {
 294         struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
 295         ev->private_data = listel;
 296         DEBUG(10, ("sys_notify_callback called with action=%d, for %s\n",
 297                    ev->action, ev->path));
 298         listel->callback(listel->private_data, ev);
 299 }
 300
 301 /*
 302   add an entry to the notify array
 303 */
 304 static NTSTATUS notify_add_array(struct notify_context *notify, struct db_record *rec,
 305                                  struct notify_entry *e,
 306                                  void *private_data, int depth)
 307 {
 308         int i;
 309         struct notify_depth *d;
 310         struct notify_entry *ee;
 311
 312         /* possibly expand the depths array */
 313         if (depth >= notify->array->num_depths) {
 314                 d = talloc_realloc(notify->array, notify->array->depth,
 315                                    struct notify_depth, depth+1);
 316                 NT_STATUS_HAVE_NO_MEMORY(d);
 317                 for (i=notify->array->num_depths;i<=depth;i++) {
 318                         ZERO_STRUCT(d[i]);
 319                 }
 320                 notify->array->depth = d;
 321                 notify->array->num_depths = depth+1;
 322         }
 323         d = &notify->array->depth[depth];
 324
 325         /* expand the entries array */
 326         ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
 327                             d->num_entries+1);
 328         NT_STATUS_HAVE_NO_MEMORY(ee);
 329         d->entries = ee;
 330
 331         d->entries[d->num_entries] = *e;
 332         d->entries[d->num_entries].private_data = private_data;
 333         d->entries[d->num_entries].server = notify->server;
 334         d->entries[d->num_entries].path_len = strlen(e->path);
 335         d->num_entries++;
 336
 337         d->max_mask |= e->filter;
 338         d->max_mask_subdir |= e->subdir_filter;
 339
 340         TYPESAFE_QSORT(d->entries, d->num_entries, notify_compare);
 341
 342         /* recalculate the maximum masks */
 343         d->max_mask = 0;
 344         d->max_mask_subdir = 0;
 345
 346         for (i=0;i<d->num_entries;i++) {
 347                 d->max_mask |= d->entries[i].filter;
 348                 d->max_mask_subdir |= d->entries[i].subdir_filter;
 349         }
 350
 351         return notify_save(notify, rec);
 352 }
 353
 354 /*
 355   Add a non-recursive watch
 356 */
 357
 358 static void notify_add_onelevel(struct notify_context *notify,
 359                                 struct notify_entry *e, void *private_data)
 360 {
 361         struct notify_entry_array *array;
 362         struct db_record *rec;
 363         DATA_BLOB blob;
 364         TDB_DATA dbuf;
 365         enum ndr_err_code ndr_err;
 366         NTSTATUS status;
 367
 368         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 369         if (array == NULL) {
 370                 return;
 371         }
 372
 373         rec = notify->db_onelevel->fetch_locked(
 374                 notify->db_onelevel, talloc_tos(),
 375                 make_tdb_data((uint8_t *)&e->dir_id, sizeof(e->dir_id)));
 376         if (rec == NULL) {
 377                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 378                            "\n", file_id_string_tos(&e->dir_id)));
 379                 TALLOC_FREE(array);
 380                 return;
 381         }
 382
 383         blob.data = (uint8_t *)rec->value.dptr;
 384         blob.length = rec->value.dsize;
 385
 386         if (blob.length > 0) {
 387                 ndr_err = ndr_pull_struct_blob(
 388                         &blob, array, NULL, array,
 389                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 390                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 391                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 392                                    ndr_errstr(ndr_err)));
 393                         TALLOC_FREE(array);
 394                         return;
 395                 }
 396                 if (DEBUGLEVEL >= 10) {
 397                         DEBUG(10, ("notify_add_onelevel:\n"));
 398                         NDR_PRINT_DEBUG(notify_entry_array, array);
 399                 }
 400         }
 401
 402         array->entries = talloc_realloc(array, array->entries,
 403                                         struct notify_entry,
 404                                         array->num_entries+1);
 405         if (array->entries == NULL) {
 406                 TALLOC_FREE(array);
 407                 return;
 408         }
 409         array->entries[array->num_entries] = *e;
 410         array->entries[array->num_entries].private_data = private_data;
 411         array->entries[array->num_entries].server = notify->server;
 412         array->num_entries += 1;
 413
 414         ndr_err = ndr_push_struct_blob(
 415                 &blob, rec, NULL, array,
 416                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 417         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 418                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 419                            ndr_errstr(ndr_err)));
 420                 TALLOC_FREE(array);
 421                 return;
 422         }
 423
 424         if (DEBUGLEVEL >= 10) {
 425                 DEBUG(10, ("notify_add_onelevel:\n"));
 426                 NDR_PRINT_DEBUG(notify_entry_array, array);
 427         }
 428
 429         dbuf.dptr = blob.data;
 430         dbuf.dsize = blob.length;
 431
 432         status = rec->store(rec, dbuf, TDB_REPLACE);
 433         TALLOC_FREE(array);
 434         if (!NT_STATUS_IS_OK(status)) {
 435                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 436                            nt_errstr(status)));
 437                 return;
 438         }
 439         e->filter = 0;
 440         return;
 441 }
 442
 443
 444 /*
 445   add a notify watch. This is called when a notify is first setup on a open
 446   directory handle.
 447 */
 448 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 449                     void (*callback)(void *, const struct notify_event *),
 450                     void *private_data)
 451 {
 452         struct notify_entry e = *e0;
 453         NTSTATUS status;
 454         char *tmp_path = NULL;
 455         struct notify_list *listel;
 456         size_t len;
 457         int depth;
 458         struct db_record *rec;
 459
 460         /* see if change notify is enabled at all */
 461         if (notify == NULL) {
 462                 return NT_STATUS_NOT_IMPLEMENTED;
 463         }
 464
 465         status = notify_fetch_locked(notify, &rec);
 466         NT_STATUS_NOT_OK_RETURN(status);
 467
 468         status = notify_load(notify, rec);
 469         if (!NT_STATUS_IS_OK(status)) {
 470                 talloc_free(rec);
 471                 return status;
 472         }
 473
 474         /* cope with /. on the end of the path */
 475         len = strlen(e.path);
 476         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 477                 tmp_path = talloc_strndup(notify, e.path, len-2);
 478                 if (tmp_path == NULL) {
 479                         status = NT_STATUS_NO_MEMORY;
 480                         goto done;
 481                 }
 482                 e.path = tmp_path;
 483         }
 484
 485         depth = count_chars(e.path, '/');
 486
 487         listel = TALLOC_ZERO_P(notify, struct notify_list);
 488         if (listel == NULL) {
 489                 status = NT_STATUS_NO_MEMORY;
 490                 goto done;
 491         }
 492
 493         listel->private_data = private_data;
 494         listel->callback = callback;
 495         listel->depth = depth;
 496         DLIST_ADD(notify->list, listel);
 497
 498         /* ignore failures from sys_notify */
 499         if (notify->sys_notify_ctx != NULL) {
 500                 /*
 501                   this call will modify e.filter and e.subdir_filter
 502                   to remove bits handled by the backend
 503                 */
 504                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 505                                           sys_notify_callback, listel,
 506                                           &listel->sys_notify_handle);
 507                 if (NT_STATUS_IS_OK(status)) {
 508                         talloc_steal(listel, listel->sys_notify_handle);
 509                 }
 510         }
 511
 512         if (e.filter != 0) {
 513                 notify_add_onelevel(notify, &e, private_data);
 514                 status = NT_STATUS_OK;
 515         }
 516
 517         /* if the system notify handler couldn't handle some of the
 518            filter bits, or couldn't handle a request for recursion
 519            then we need to install it in the array used for the
 520            intra-samba notify handling */
 521         if (e.filter != 0 || e.subdir_filter != 0) {
 522                 status = notify_add_array(notify, rec, &e, private_data, depth);
 523         }
 524
 525 done:
 526         talloc_free(rec);
 527         talloc_free(tmp_path);
 528
 529         return status;
 530 }
 531
 532 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 533                                 const struct file_id *fid,
 534                                 void *private_data)
 535 {
 536         struct notify_entry_array *array;
 537         struct db_record *rec;
 538         DATA_BLOB blob;
 539         TDB_DATA dbuf;
 540         enum ndr_err_code ndr_err;
 541         NTSTATUS status;
 542         int i;
 543
 544         if (notify == NULL) {
 545                 return NT_STATUS_NOT_IMPLEMENTED;
 546         }
 547
 548         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 549         if (array == NULL) {
 550                 return NT_STATUS_NO_MEMORY;
 551         }
 552
 553         rec = notify->db_onelevel->fetch_locked(
 554                 notify->db_onelevel, array,
 555                 make_tdb_data((uint8_t *)fid, sizeof(*fid)));
 556         if (rec == NULL) {
 557                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 558                            "\n", file_id_string_tos(fid)));
 559                 TALLOC_FREE(array);
 560                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 561         }
 562
 563         blob.data = (uint8_t *)rec->value.dptr;
 564         blob.length = rec->value.dsize;
 565
 566         if (blob.length > 0) {
 567                 ndr_err = ndr_pull_struct_blob(
 568                         &blob, array, NULL, array,
 569                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 570                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 571                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 572                                    ndr_errstr(ndr_err)));
 573                         TALLOC_FREE(array);
 574                         return ndr_map_error2ntstatus(ndr_err);
 575                 }
 576                 if (DEBUGLEVEL >= 10) {
 577                         DEBUG(10, ("notify_remove_onelevel:\n"));
 578                         NDR_PRINT_DEBUG(notify_entry_array, array);
 579                 }
 580         }
 581
 582         for (i=0; i<array->num_entries; i++) {
 583                 if ((private_data == array->entries[i].private_data) &&
 584                     cluster_id_equal(&notify->server,
 585                                      &array->entries[i].server)) {
 586                         break;
 587                 }
 588         }
 589
 590         if (i == array->num_entries) {
 591                 TALLOC_FREE(array);
 592                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 593         }
 594
 595         array->entries[i] = array->entries[array->num_entries-1];
 596         array->num_entries -= 1;
 597
 598         if (array->num_entries == 0) {
 599                 rec->delete_rec(rec);
 600                 TALLOC_FREE(array);
 601                 return NT_STATUS_OK;
 602         }
 603
 604         ndr_err = ndr_push_struct_blob(
 605                 &blob, rec, NULL, array,
 606                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 607         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 608                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 609                            ndr_errstr(ndr_err)));
 610                 TALLOC_FREE(array);
 611                 return ndr_map_error2ntstatus(ndr_err);
 612         }
 613
 614         if (DEBUGLEVEL >= 10) {
 615                 DEBUG(10, ("notify_add_onelevel:\n"));
 616                 NDR_PRINT_DEBUG(notify_entry_array, array);
 617         }
 618
 619         dbuf.dptr = blob.data;
 620         dbuf.dsize = blob.length;
 621
 622         status = rec->store(rec, dbuf, TDB_REPLACE);
 623         TALLOC_FREE(array);
 624         if (!NT_STATUS_IS_OK(status)) {
 625                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 626                            nt_errstr(status)));
 627                 return status;
 628         }
 629         return NT_STATUS_OK;
 630 }
 631
 632 /*
 633   remove a notify watch. Called when the directory handle is closed
 634 */
 635 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 636 {
 637         NTSTATUS status;
 638         struct notify_list *listel;
 639         int i, depth;
 640         struct notify_depth *d;
 641         struct db_record *rec;
 642
 643         /* see if change notify is enabled at all */
 644         if (notify == NULL) {
 645                 return NT_STATUS_NOT_IMPLEMENTED;
 646         }
 647
 648         for (listel=notify->list;listel;listel=listel->next) {
 649                 if (listel->private_data == private_data) {
 650                         DLIST_REMOVE(notify->list, listel);
 651                         break;
 652                 }
 653         }
 654         if (listel == NULL) {
 655                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 656         }
 657
 658         depth = listel->depth;
 659
 660         talloc_free(listel);
 661
 662         status = notify_fetch_locked(notify, &rec);
 663         NT_STATUS_NOT_OK_RETURN(status);
 664
 665         status = notify_load(notify, rec);
 666         if (!NT_STATUS_IS_OK(status)) {
 667                 talloc_free(rec);
 668                 return status;
 669         }
 670
 671         if (depth >= notify->array->num_depths) {
 672                 talloc_free(rec);
 673                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 674         }
 675
 676         /* we only have to search at the depth of this element */
 677         d = &notify->array->depth[depth];
 678
 679         for (i=0;i<d->num_entries;i++) {
 680                 if (private_data == d->entries[i].private_data &&
 681                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 682                         break;
 683                 }
 684         }
 685         if (i == d->num_entries) {
 686                 talloc_free(rec);
 687                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 688         }
 689
 690         if (i < d->num_entries-1) {
 691                 memmove(&d->entries[i], &d->entries[i+1],
 692                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 693         }
 694         d->num_entries--;
 695
 696         status = notify_save(notify, rec);
 697
 698         talloc_free(rec);
 699
 700         return status;
 701 }
 702
 703 /*
 704   remove all notify watches for a messaging server
 705 */
 706 static NTSTATUS notify_remove_all(struct notify_context *notify,
 707                                   const struct server_id *server)
 708 {
 709         NTSTATUS status;
 710         int i, depth, del_count=0;
 711         struct db_record *rec;
 712
 713         status = notify_fetch_locked(notify, &rec);
 714         NT_STATUS_NOT_OK_RETURN(status);
 715
 716         status = notify_load(notify, rec);
 717         if (!NT_STATUS_IS_OK(status)) {
 718                 talloc_free(rec);
 719                 return status;
 720         }
 721
 722         /* we have to search for all entries across all depths, looking for matches
 723            for the server id */
 724         for (depth=0;depth<notify->array->num_depths;depth++) {
 725                 struct notify_depth *d = &notify->array->depth[depth];
 726                 for (i=0;i<d->num_entries;i++) {
 727                         if (cluster_id_equal(server, &d->entries[i].server)) {
 728                                 if (i < d->num_entries-1) {
 729                                         memmove(&d->entries[i], &d->entries[i+1],
 730                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 731                                 }
 732                                 i--;
 733                                 d->num_entries--;
 734                                 del_count++;
 735                         }
 736                 }
 737         }
 738
 739         if (del_count > 0) {
 740                 status = notify_save(notify, rec);
 741         }
 742
 743         talloc_free(rec);
 744
 745         return status;
 746 }
 747
 748
 749 /*
 750   send a notify message to another messaging server
 751 */
 752 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 753                             const char *path, uint32_t action)
 754 {
 755         struct notify_event ev;
 756         DATA_BLOB data;
 757         NTSTATUS status;
 758         enum ndr_err_code ndr_err;
 759         TALLOC_CTX *tmp_ctx;
 760
 761         ev.action = action;
 762         ev.path = path;
 763         ev.private_data = e->private_data;
 764
 765         tmp_ctx = talloc_new(notify);
 766
 767         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, NULL, &ev,
 768                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 769         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 770                 talloc_free(tmp_ctx);
 771                 return ndr_map_error2ntstatus(ndr_err);
 772         }
 773
 774         status = messaging_send(notify->messaging_ctx, e->server,
 775                                 MSG_PVFS_NOTIFY, &data);
 776         talloc_free(tmp_ctx);
 777         return status;
 778 }
 779
 780 void notify_onelevel(struct notify_context *notify, uint32_t action,
 781                      uint32_t filter, struct file_id fid, const char *name)
 782 {
 783         struct notify_entry_array *array;
 784         TDB_DATA dbuf;
 785         DATA_BLOB blob;
 786         bool have_dead_entries = false;
 787         int i;
 788
 789         if (notify == NULL) {
 790                 return;
 791         }
 792
 793         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 794         if (array == NULL) {
 795                 return;
 796         }
 797
 798         if (notify->db_onelevel->fetch(
 799                     notify->db_onelevel, array,
 800                     make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 801                     &dbuf) == -1) {
 802                 TALLOC_FREE(array);
 803                 return;
 804         }
 805
 806         blob.data = (uint8 *)dbuf.dptr;
 807         blob.length = dbuf.dsize;
 808
 809         if (blob.length > 0) {
 810                 enum ndr_err_code ndr_err;
 811                 ndr_err = ndr_pull_struct_blob(
 812                         &blob, array, NULL, array,
 813                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 814                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 815                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 816                                    ndr_errstr(ndr_err)));
 817                         TALLOC_FREE(array);
 818                         return;
 819                 }
 820                 if (DEBUGLEVEL >= 10) {
 821                         DEBUG(10, ("notify_onelevel:\n"));
 822                         NDR_PRINT_DEBUG(notify_entry_array, array);
 823                 }
 824         }
 825
 826         for (i=0; i<array->num_entries; i++) {
 827                 struct notify_entry *e = &array->entries[i];
 828
 829                 if ((e->filter & filter) != 0) {
 830                         NTSTATUS status;
 831
 832                         status = notify_send(notify, e, name, action);
 833                         if (NT_STATUS_EQUAL(
 834                                     status, NT_STATUS_INVALID_HANDLE)) {
 835                                 /*
 836                                  * Mark the entry as dead. All entries have a
 837                                  * path set. The marker used here is setting
 838                                  * that to NULL.
 839                                  */
 840                                 e->path = NULL;
 841                                 have_dead_entries = true;
 842                         }
 843                 }
 844         }
 845
 846         if (!have_dead_entries) {
 847                 TALLOC_FREE(array);
 848                 return;
 849         }
 850
 851         for (i=0; i<array->num_entries; i++) {
 852                 struct notify_entry *e = &array->entries[i];
 853                 if (e->path != NULL) {
 854                         continue;
 855                 }
 856                 DEBUG(10, ("Deleting notify entries for process %s because "
 857                            "it's gone\n", procid_str_static(&e->server)));
 858                 /*
 859                  * Potential TODO: This might need optimizing,
 860                  * notify_remove_onelevel() does a fetch_locked() operation at
 861                  * every call. But this would only matter if a process with
 862                  * MANY notifies has died without shutting down properly.
 863                  */
 864                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 865         }
 866
 867         TALLOC_FREE(array);
 868         return;
 869 }
 870
 871 /*
 872   trigger a notify message for anyone waiting on a matching event
 873
 874   This function is called a lot, and needs to be very fast. The unusual data structure
 875   and traversal is designed to be fast in the average case, even for large numbers of
 876   notifies
 877 */
 878 void notify_trigger(struct notify_context *notify,
 879                     uint32_t action, uint32_t filter, const char *path)
 880 {
 881         NTSTATUS status;
 882         int depth;
 883         const char *p, *next_p;
 884
 885         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 886                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 887
 888         /* see if change notify is enabled at all */
 889         if (notify == NULL) {
 890                 return;
 891         }
 892
 893  again:
 894         status = notify_load(notify, NULL);
 895         if (!NT_STATUS_IS_OK(status)) {
 896                 return;
 897         }
 898
 899         /* loop along the given path, working with each directory depth separately */
 900         for (depth=0,p=path;
 901              p && depth < notify->array->num_depths;
 902              p=next_p,depth++) {
 903                 int p_len = p - path;
 904                 int min_i, max_i, i;
 905                 struct notify_depth *d = &notify->array->depth[depth];
 906                 next_p = strchr(p+1, '/');
 907
 908                 /* see if there are any entries at this depth */
 909                 if (d->num_entries == 0) continue;
 910
 911                 /* try to skip based on the maximum mask. If next_p is
 912                  NULL then we know it will be a 'this directory'
 913                  match, otherwise it must be a subdir match */
 914                 if (next_p != NULL) {
 915                         if (0 == (filter & d->max_mask_subdir)) {
 916                                 continue;
 917                         }
 918                 } else {
 919                         if (0 == (filter & d->max_mask)) {
 920                                 continue;
 921                         }
 922                 }
 923
 924                 /* we know there is an entry here worth looking
 925                  for. Use a bisection search to find the first entry
 926                  with a matching path */
 927                 min_i = 0;
 928                 max_i = d->num_entries-1;
 929
 930                 while (min_i < max_i) {
 931                         struct notify_entry *e;
 932                         int cmp;
 933                         i = (min_i+max_i)/2;
 934                         e = &d->entries[i];
 935                         cmp = strncmp(path, e->path, p_len);
 936                         if (cmp == 0) {
 937                                 if (p_len == e->path_len) {
 938                                         max_i = i;
 939                                 } else {
 940                                         max_i = i-1;
 941                                 }
 942                         } else if (cmp < 0) {
 943                                 max_i = i-1;
 944                         } else {
 945                                 min_i = i+1;
 946                         }
 947                 }
 948
 949                 if (min_i != max_i) {
 950                         /* none match */
 951                         continue;
 952                 }
 953
 954                 /* we now know that the entries start at min_i */
 955                 for (i=min_i;i<d->num_entries;i++) {
 956                         struct notify_entry *e = &d->entries[i];
 957                         if (p_len != e->path_len ||
 958                             strncmp(path, e->path, p_len) != 0) break;
 959                         if (next_p != NULL) {
 960                                 if (0 == (filter & e->subdir_filter)) {
 961                                         continue;
 962                                 }
 963                         } else {
 964                                 if (0 == (filter & e->filter)) {
 965                                         continue;
 966                                 }
 967                         }
 968                         status = notify_send(notify, e, path + e->path_len + 1,
 969                                              action);
 970
 971                         if (NT_STATUS_EQUAL(
 972                                     status, NT_STATUS_INVALID_HANDLE)) {
 973                                 struct server_id server = e->server;
 974
 975                                 DEBUG(10, ("Deleting notify entries for "
 976                                            "process %s because it's gone\n",
 977                                            procid_str_static(&e->server)));
 978                                 notify_remove_all(notify, &server);
 979                                 goto again;
 980                         }
 981                 }
 982         }
 983 }