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/dbwrap.h"
  30 #include "dbwrap/dbwrap_open.h"
  31 #include "smbd/smbd.h"
  32 #include "messages.h"
  33 #include "lib/util/tdb_wrap.h"
  34 #include "util_tdb.h"
  35
  36 struct notify_context {
  37         struct db_context *db_recursive;
  38         struct db_context *db_onelevel;
  39         struct server_id server;
  40         struct messaging_context *messaging_ctx;
  41         struct notify_list *list;
  42         struct notify_array *array;
  43         int seqnum;
  44         struct sys_notify_context *sys_notify_ctx;
  45         TDB_DATA key;
  46 };
  47
  48
  49 struct notify_list {
  50         struct notify_list *next, *prev;
  51         void *private_data;
  52         void (*callback)(void *, const struct notify_event *);
  53         void *sys_notify_handle;
  54         int depth;
  55 };
  56
  57 #define NOTIFY_KEY "notify array"
  58
  59 #define NOTIFY_ENABLE           "notify:enable"
  60 #define NOTIFY_ENABLE_DEFAULT   True
  61
  62 static NTSTATUS notify_remove_all(struct notify_context *notify,
  63                                   const struct server_id *server);
  64 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
  65                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
  66
  67 /*
  68   destroy the notify context
  69 */
  70 static int notify_destructor(struct notify_context *notify)
  71 {
  72         messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
  73
  74         if (notify->list != NULL) {
  75                 notify_remove_all(notify, &notify->server);
  76         }
  77
  78         return 0;
  79 }
  80
  81 /*
  82   Open up the notify.tdb database. You should close it down using
  83   talloc_free(). We need the messaging_ctx to allow for notifications
  84   via internal messages
  85 */
  86 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
  87                                    struct messaging_context *messaging_ctx,
  88                                    struct event_context *ev,
  89                                    connection_struct *conn)
  90 {
  91         struct notify_context *notify;
  92
  93         if (!lp_change_notify(conn->params)) {
  94                 return NULL;
  95         }
  96
  97         notify = talloc(mem_ctx, struct notify_context);
  98         if (notify == NULL) {
  99                 return NULL;
 100         }
 101
 102         notify->db_recursive = db_open(notify, lock_path("notify.tdb"),
 103                                        0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 104                                        O_RDWR|O_CREAT, 0644);
 105         if (notify->db_recursive == NULL) {
 106                 talloc_free(notify);
 107                 return NULL;
 108         }
 109
 110         notify->db_onelevel = db_open(notify, lock_path("notify_onelevel.tdb"),
 111                                       0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 112                                       O_RDWR|O_CREAT, 0644);
 113         if (notify->db_onelevel == NULL) {
 114                 talloc_free(notify);
 115                 return NULL;
 116         }
 117
 118         notify->server = server;
 119         notify->messaging_ctx = messaging_ctx;
 120         notify->list = NULL;
 121         notify->array = NULL;
 122         notify->seqnum = dbwrap_get_seqnum(notify->db_recursive);
 123         notify->key = string_term_tdb_data(NOTIFY_KEY);
 124
 125         talloc_set_destructor(notify, notify_destructor);
 126
 127         /* register with the messaging subsystem for the notify
 128            message type */
 129         messaging_register(notify->messaging_ctx, notify,
 130                            MSG_PVFS_NOTIFY, notify_handler);
 131
 132         notify->sys_notify_ctx = sys_notify_context_create(conn, notify, ev);
 133
 134         return notify;
 135 }
 136
 137 bool notify_internal_parent_init(TALLOC_CTX *mem_ctx)
 138 {
 139         struct tdb_wrap *db1, *db2;
 140
 141         if (lp_clustering()) {
 142                 return true;
 143         }
 144
 145         /*
 146          * Open the tdbs in the parent process (smbd) so that our
 147          * CLEAR_IF_FIRST optimization in tdb_reopen_all can properly
 148          * work.
 149          */
 150
 151         db1 = tdb_wrap_open(mem_ctx, lock_path("notify.tdb"),
 152                             0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 153                            O_RDWR|O_CREAT, 0644);
 154         if (db1 == NULL) {
 155                 DEBUG(1, ("could not open notify.tdb: %s\n", strerror(errno)));
 156                 return false;
 157         }
 158         db2 = tdb_wrap_open(mem_ctx, lock_path("notify_onelevel.tdb"),
 159                             0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDWR|O_CREAT, 0644);
 160         if (db2 == NULL) {
 161                 DEBUG(1, ("could not open notify_onelevel.tdb: %s\n",
 162                           strerror(errno)));
 163                 TALLOC_FREE(db1);
 164                 return false;
 165         }
 166         return true;
 167 }
 168
 169 /*
 170   lock and fetch the record
 171 */
 172 static NTSTATUS notify_fetch_locked(struct notify_context *notify, struct db_record **rec)
 173 {
 174         *rec = dbwrap_fetch_locked(notify->db_recursive, 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 = dbwrap_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(notify, struct notify_array);
 201         NT_STATUS_HAVE_NO_MEMORY(notify->array);
 202
 203         if (!rec) {
 204                 status = dbwrap_fetch(notify->db_recursive, notify,
 205                                       notify->key, &dbuf);
 206                 if (!NT_STATUS_IS_OK(status)) {
 207                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 208                 }
 209         } else {
 210                 dbuf = dbwrap_record_get_value(rec);
 211         }
 212
 213         blob.data = (uint8 *)dbuf.dptr;
 214         blob.length = dbuf.dsize;
 215
 216         status = NT_STATUS_OK;
 217         if (blob.length > 0) {
 218                 enum ndr_err_code ndr_err;
 219                 ndr_err = ndr_pull_struct_blob(&blob, notify->array, notify->array,
 220                                                (ndr_pull_flags_fn_t)ndr_pull_notify_array);
 221                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 222                         /* 1. log that we got a corrupt notify_array
 223                          * 2. clear the variable the garbage was stored into to not trip
 224                          *  over it next time this method is entered with the same seqnum
 225                          * 3. delete it from the database */
 226                         DEBUG(2, ("notify_array is corrupt, discarding it\n"));
 227
 228                         ZERO_STRUCTP(notify->array);
 229                         if (rec != NULL) {
 230                                 dbwrap_record_delete(rec);
 231                         }
 232
 233                 } else {
 234                         if (DEBUGLEVEL >= 10) {
 235                                 DEBUG(10, ("notify_load:\n"));
 236                                 NDR_PRINT_DEBUG(notify_array, notify->array);
 237                         }
 238                 }
 239         }
 240
 241
 242         if (!rec) {
 243                 talloc_free(dbuf.dptr);
 244         }
 245
 246         return status;
 247 }
 248
 249 /*
 250   compare notify entries for sorting
 251 */
 252 static int notify_compare(const struct notify_entry *e1, const struct notify_entry *e2)
 253 {
 254         return strcmp(e1->path, e2->path);
 255 }
 256
 257 /*
 258   save the notify array
 259 */
 260 static NTSTATUS notify_save(struct notify_context *notify, struct db_record *rec)
 261 {
 262         TDB_DATA dbuf;
 263         DATA_BLOB blob;
 264         NTSTATUS status;
 265         enum ndr_err_code ndr_err;
 266         TALLOC_CTX *tmp_ctx;
 267
 268         /* if possible, remove some depth arrays */
 269         while (notify->array->num_depths > 0 &&
 270                notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
 271                 notify->array->num_depths--;
 272         }
 273
 274         /* we might just be able to delete the record */
 275         if (notify->array->num_depths == 0) {
 276                 return dbwrap_record_delete(rec);
 277         }
 278
 279         tmp_ctx = talloc_new(notify);
 280         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 281
 282         ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, notify->array,
 283                                       (ndr_push_flags_fn_t)ndr_push_notify_array);
 284         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 285                 talloc_free(tmp_ctx);
 286                 return ndr_map_error2ntstatus(ndr_err);
 287         }
 288
 289         if (DEBUGLEVEL >= 10) {
 290                 DEBUG(10, ("notify_save:\n"));
 291                 NDR_PRINT_DEBUG(notify_array, notify->array);
 292         }
 293
 294         dbuf.dptr = blob.data;
 295         dbuf.dsize = blob.length;
 296
 297         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 298         talloc_free(tmp_ctx);
 299
 300         return status;
 301 }
 302
 303
 304 /*
 305   handle incoming notify messages
 306 */
 307 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
 308                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
 309 {
 310         struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
 311         enum ndr_err_code ndr_err;
 312         struct notify_event ev;
 313         TALLOC_CTX *tmp_ctx = talloc_new(notify);
 314         struct notify_list *listel;
 315
 316         if (tmp_ctx == NULL) {
 317                 return;
 318         }
 319
 320         ndr_err = ndr_pull_struct_blob(data, tmp_ctx, &ev,
 321                                        (ndr_pull_flags_fn_t)ndr_pull_notify_event);
 322         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 323                 talloc_free(tmp_ctx);
 324                 return;
 325         }
 326
 327         for (listel=notify->list;listel;listel=listel->next) {
 328                 if (listel->private_data == ev.private_data) {
 329                         listel->callback(listel->private_data, &ev);
 330                         break;
 331                 }
 332         }
 333
 334         talloc_free(tmp_ctx);
 335 }
 336
 337 /*
 338   callback from sys_notify telling us about changes from the OS
 339 */
 340 static void sys_notify_callback(struct sys_notify_context *ctx,
 341                                 void *ptr, struct notify_event *ev)
 342 {
 343         struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
 344         ev->private_data = listel;
 345         DEBUG(10, ("sys_notify_callback called with action=%d, for %s\n",
 346                    ev->action, ev->path));
 347         listel->callback(listel->private_data, ev);
 348 }
 349
 350 /*
 351   add an entry to the notify array
 352 */
 353 static NTSTATUS notify_add_array(struct notify_context *notify, struct db_record *rec,
 354                                  struct notify_entry *e,
 355                                  void *private_data, int depth)
 356 {
 357         int i;
 358         struct notify_depth *d;
 359         struct notify_entry *ee;
 360
 361         /* possibly expand the depths array */
 362         if (depth >= notify->array->num_depths) {
 363                 d = talloc_realloc(notify->array, notify->array->depth,
 364                                    struct notify_depth, depth+1);
 365                 NT_STATUS_HAVE_NO_MEMORY(d);
 366                 for (i=notify->array->num_depths;i<=depth;i++) {
 367                         ZERO_STRUCT(d[i]);
 368                 }
 369                 notify->array->depth = d;
 370                 notify->array->num_depths = depth+1;
 371         }
 372         d = &notify->array->depth[depth];
 373
 374         /* expand the entries array */
 375         ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
 376                             d->num_entries+1);
 377         NT_STATUS_HAVE_NO_MEMORY(ee);
 378         d->entries = ee;
 379
 380         d->entries[d->num_entries] = *e;
 381         d->entries[d->num_entries].private_data = private_data;
 382         d->entries[d->num_entries].server = notify->server;
 383         d->entries[d->num_entries].path_len = strlen(e->path);
 384         d->num_entries++;
 385
 386         d->max_mask |= e->filter;
 387         d->max_mask_subdir |= e->subdir_filter;
 388
 389         TYPESAFE_QSORT(d->entries, d->num_entries, notify_compare);
 390
 391         /* recalculate the maximum masks */
 392         d->max_mask = 0;
 393         d->max_mask_subdir = 0;
 394
 395         for (i=0;i<d->num_entries;i++) {
 396                 d->max_mask |= d->entries[i].filter;
 397                 d->max_mask_subdir |= d->entries[i].subdir_filter;
 398         }
 399
 400         return notify_save(notify, rec);
 401 }
 402
 403 /*
 404   Add a non-recursive watch
 405 */
 406
 407 static void notify_add_onelevel(struct notify_context *notify,
 408                                 struct notify_entry *e, void *private_data)
 409 {
 410         struct notify_entry_array *array;
 411         struct db_record *rec;
 412         DATA_BLOB blob;
 413         TDB_DATA dbuf;
 414         TDB_DATA value;
 415         enum ndr_err_code ndr_err;
 416         NTSTATUS status;
 417
 418         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 419         if (array == NULL) {
 420                 return;
 421         }
 422
 423         rec = dbwrap_fetch_locked(notify->db_onelevel, talloc_tos(),
 424                                   make_tdb_data((uint8_t *)&e->dir_id,
 425                                    sizeof(e->dir_id)));
 426         if (rec == NULL) {
 427                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 428                            "\n", file_id_string_tos(&e->dir_id)));
 429                 TALLOC_FREE(array);
 430                 return;
 431         }
 432
 433         value = dbwrap_record_get_value(rec);
 434         blob.data = (uint8_t *)value.dptr;
 435         blob.length = value.dsize;
 436
 437         if (blob.length > 0) {
 438                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 439                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 440                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 441                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 442                                    ndr_errstr(ndr_err)));
 443                         TALLOC_FREE(array);
 444                         return;
 445                 }
 446                 if (DEBUGLEVEL >= 10) {
 447                         DEBUG(10, ("notify_add_onelevel:\n"));
 448                         NDR_PRINT_DEBUG(notify_entry_array, array);
 449                 }
 450         }
 451
 452         array->entries = talloc_realloc(array, array->entries,
 453                                         struct notify_entry,
 454                                         array->num_entries+1);
 455         if (array->entries == NULL) {
 456                 TALLOC_FREE(array);
 457                 return;
 458         }
 459         array->entries[array->num_entries] = *e;
 460         array->entries[array->num_entries].private_data = private_data;
 461         array->entries[array->num_entries].server = notify->server;
 462         array->num_entries += 1;
 463
 464         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 465                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 466         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 467                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 468                            ndr_errstr(ndr_err)));
 469                 TALLOC_FREE(array);
 470                 return;
 471         }
 472
 473         if (DEBUGLEVEL >= 10) {
 474                 DEBUG(10, ("notify_add_onelevel:\n"));
 475                 NDR_PRINT_DEBUG(notify_entry_array, array);
 476         }
 477
 478         dbuf.dptr = blob.data;
 479         dbuf.dsize = blob.length;
 480
 481         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 482         TALLOC_FREE(array);
 483         if (!NT_STATUS_IS_OK(status)) {
 484                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 485                            nt_errstr(status)));
 486                 return;
 487         }
 488         e->filter = 0;
 489         return;
 490 }
 491
 492
 493 /*
 494   add a notify watch. This is called when a notify is first setup on a open
 495   directory handle.
 496 */
 497 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 498                     void (*callback)(void *, const struct notify_event *),
 499                     void *private_data)
 500 {
 501         struct notify_entry e = *e0;
 502         NTSTATUS status;
 503         char *tmp_path = NULL;
 504         struct notify_list *listel;
 505         size_t len;
 506         int depth;
 507         struct db_record *rec;
 508
 509         /* see if change notify is enabled at all */
 510         if (notify == NULL) {
 511                 return NT_STATUS_NOT_IMPLEMENTED;
 512         }
 513
 514         status = notify_fetch_locked(notify, &rec);
 515         NT_STATUS_NOT_OK_RETURN(status);
 516
 517         status = notify_load(notify, rec);
 518         if (!NT_STATUS_IS_OK(status)) {
 519                 talloc_free(rec);
 520                 return status;
 521         }
 522
 523         /* cope with /. on the end of the path */
 524         len = strlen(e.path);
 525         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 526                 tmp_path = talloc_strndup(notify, e.path, len-2);
 527                 if (tmp_path == NULL) {
 528                         status = NT_STATUS_NO_MEMORY;
 529                         goto done;
 530                 }
 531                 e.path = tmp_path;
 532         }
 533
 534         depth = count_chars(e.path, '/');
 535
 536         listel = talloc_zero(notify, struct notify_list);
 537         if (listel == NULL) {
 538                 status = NT_STATUS_NO_MEMORY;
 539                 goto done;
 540         }
 541
 542         listel->private_data = private_data;
 543         listel->callback = callback;
 544         listel->depth = depth;
 545         DLIST_ADD(notify->list, listel);
 546
 547         /* ignore failures from sys_notify */
 548         if (notify->sys_notify_ctx != NULL) {
 549                 /*
 550                   this call will modify e.filter and e.subdir_filter
 551                   to remove bits handled by the backend
 552                 */
 553                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 554                                           sys_notify_callback, listel,
 555                                           &listel->sys_notify_handle);
 556                 if (NT_STATUS_IS_OK(status)) {
 557                         talloc_steal(listel, listel->sys_notify_handle);
 558                 }
 559         }
 560
 561         if (e.filter != 0) {
 562                 notify_add_onelevel(notify, &e, private_data);
 563                 status = NT_STATUS_OK;
 564         }
 565
 566         /* if the system notify handler couldn't handle some of the
 567            filter bits, or couldn't handle a request for recursion
 568            then we need to install it in the array used for the
 569            intra-samba notify handling */
 570         if (e.filter != 0 || e.subdir_filter != 0) {
 571                 status = notify_add_array(notify, rec, &e, private_data, depth);
 572         }
 573
 574 done:
 575         talloc_free(rec);
 576         talloc_free(tmp_path);
 577
 578         return status;
 579 }
 580
 581 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 582                                 const struct file_id *fid,
 583                                 void *private_data)
 584 {
 585         struct notify_entry_array *array;
 586         struct db_record *rec;
 587         DATA_BLOB blob;
 588         TDB_DATA dbuf;
 589         TDB_DATA value;
 590         enum ndr_err_code ndr_err;
 591         NTSTATUS status;
 592         int i;
 593
 594         if (notify == NULL) {
 595                 return NT_STATUS_NOT_IMPLEMENTED;
 596         }
 597
 598         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 599         if (array == NULL) {
 600                 return NT_STATUS_NO_MEMORY;
 601         }
 602
 603         rec = dbwrap_fetch_locked(
 604                 notify->db_onelevel, array,
 605                 make_tdb_data((const uint8_t *)fid, sizeof(*fid)));
 606         if (rec == NULL) {
 607                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 608                            "\n", file_id_string_tos(fid)));
 609                 TALLOC_FREE(array);
 610                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 611         }
 612
 613         value = dbwrap_record_get_value(rec);
 614         blob.data = (uint8_t *)value.dptr;
 615         blob.length = value.dsize;
 616
 617         if (blob.length > 0) {
 618                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 619                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 620                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 621                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 622                                    ndr_errstr(ndr_err)));
 623                         TALLOC_FREE(array);
 624                         return ndr_map_error2ntstatus(ndr_err);
 625                 }
 626                 if (DEBUGLEVEL >= 10) {
 627                         DEBUG(10, ("notify_remove_onelevel:\n"));
 628                         NDR_PRINT_DEBUG(notify_entry_array, array);
 629                 }
 630         }
 631
 632         for (i=0; i<array->num_entries; i++) {
 633                 if ((private_data == array->entries[i].private_data) &&
 634                     cluster_id_equal(&notify->server,
 635                                      &array->entries[i].server)) {
 636                         break;
 637                 }
 638         }
 639
 640         if (i == array->num_entries) {
 641                 TALLOC_FREE(array);
 642                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 643         }
 644
 645         array->entries[i] = array->entries[array->num_entries-1];
 646         array->num_entries -= 1;
 647
 648         if (array->num_entries == 0) {
 649                 dbwrap_record_delete(rec);
 650                 TALLOC_FREE(array);
 651                 return NT_STATUS_OK;
 652         }
 653
 654         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 655                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 656         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 657                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 658                            ndr_errstr(ndr_err)));
 659                 TALLOC_FREE(array);
 660                 return ndr_map_error2ntstatus(ndr_err);
 661         }
 662
 663         if (DEBUGLEVEL >= 10) {
 664                 DEBUG(10, ("notify_add_onelevel:\n"));
 665                 NDR_PRINT_DEBUG(notify_entry_array, array);
 666         }
 667
 668         dbuf.dptr = blob.data;
 669         dbuf.dsize = blob.length;
 670
 671         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 672         TALLOC_FREE(array);
 673         if (!NT_STATUS_IS_OK(status)) {
 674                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 675                            nt_errstr(status)));
 676                 return status;
 677         }
 678         return NT_STATUS_OK;
 679 }
 680
 681 /*
 682   remove a notify watch. Called when the directory handle is closed
 683 */
 684 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 685 {
 686         NTSTATUS status;
 687         struct notify_list *listel;
 688         int i, depth;
 689         struct notify_depth *d;
 690         struct db_record *rec;
 691
 692         /* see if change notify is enabled at all */
 693         if (notify == NULL) {
 694                 return NT_STATUS_NOT_IMPLEMENTED;
 695         }
 696
 697         for (listel=notify->list;listel;listel=listel->next) {
 698                 if (listel->private_data == private_data) {
 699                         DLIST_REMOVE(notify->list, listel);
 700                         break;
 701                 }
 702         }
 703         if (listel == NULL) {
 704                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 705         }
 706
 707         depth = listel->depth;
 708
 709         talloc_free(listel);
 710
 711         status = notify_fetch_locked(notify, &rec);
 712         NT_STATUS_NOT_OK_RETURN(status);
 713
 714         status = notify_load(notify, rec);
 715         if (!NT_STATUS_IS_OK(status)) {
 716                 talloc_free(rec);
 717                 return status;
 718         }
 719
 720         if (depth >= notify->array->num_depths) {
 721                 talloc_free(rec);
 722                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 723         }
 724
 725         /* we only have to search at the depth of this element */
 726         d = &notify->array->depth[depth];
 727
 728         for (i=0;i<d->num_entries;i++) {
 729                 if (private_data == d->entries[i].private_data &&
 730                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 731                         break;
 732                 }
 733         }
 734         if (i == d->num_entries) {
 735                 talloc_free(rec);
 736                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 737         }
 738
 739         if (i < d->num_entries-1) {
 740                 memmove(&d->entries[i], &d->entries[i+1],
 741                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 742         }
 743         d->num_entries--;
 744
 745         status = notify_save(notify, rec);
 746
 747         talloc_free(rec);
 748
 749         return status;
 750 }
 751
 752 /*
 753   remove all notify watches for a messaging server
 754 */
 755 static NTSTATUS notify_remove_all(struct notify_context *notify,
 756                                   const struct server_id *server)
 757 {
 758         NTSTATUS status;
 759         int i, depth, del_count=0;
 760         struct db_record *rec;
 761
 762         status = notify_fetch_locked(notify, &rec);
 763         NT_STATUS_NOT_OK_RETURN(status);
 764
 765         status = notify_load(notify, rec);
 766         if (!NT_STATUS_IS_OK(status)) {
 767                 talloc_free(rec);
 768                 return status;
 769         }
 770
 771         /* we have to search for all entries across all depths, looking for matches
 772            for the server id */
 773         for (depth=0;depth<notify->array->num_depths;depth++) {
 774                 struct notify_depth *d = &notify->array->depth[depth];
 775                 for (i=0;i<d->num_entries;i++) {
 776                         if (cluster_id_equal(server, &d->entries[i].server)) {
 777                                 if (i < d->num_entries-1) {
 778                                         memmove(&d->entries[i], &d->entries[i+1],
 779                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 780                                 }
 781                                 i--;
 782                                 d->num_entries--;
 783                                 del_count++;
 784                         }
 785                 }
 786         }
 787
 788         if (del_count > 0) {
 789                 status = notify_save(notify, rec);
 790         }
 791
 792         talloc_free(rec);
 793
 794         return status;
 795 }
 796
 797
 798 /*
 799   send a notify message to another messaging server
 800 */
 801 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 802                             const char *path, uint32_t action)
 803 {
 804         struct notify_event ev;
 805         DATA_BLOB data;
 806         NTSTATUS status;
 807         enum ndr_err_code ndr_err;
 808         TALLOC_CTX *tmp_ctx;
 809
 810         ev.action = action;
 811         ev.path = path;
 812         ev.private_data = e->private_data;
 813
 814         tmp_ctx = talloc_new(notify);
 815
 816         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, &ev,
 817                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 818         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 819                 talloc_free(tmp_ctx);
 820                 return ndr_map_error2ntstatus(ndr_err);
 821         }
 822
 823         status = messaging_send(notify->messaging_ctx, e->server,
 824                                 MSG_PVFS_NOTIFY, &data);
 825         talloc_free(tmp_ctx);
 826         return status;
 827 }
 828
 829 void notify_onelevel(struct notify_context *notify, uint32_t action,
 830                      uint32_t filter, struct file_id fid, const char *name)
 831 {
 832         struct notify_entry_array *array;
 833         TDB_DATA dbuf;
 834         DATA_BLOB blob;
 835         bool have_dead_entries = false;
 836         int i;
 837         NTSTATUS status;
 838
 839         if (notify == NULL) {
 840                 return;
 841         }
 842
 843         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 844         if (array == NULL) {
 845                 return;
 846         }
 847
 848         status = dbwrap_fetch(notify->db_onelevel, array,
 849                               make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 850                               &dbuf);
 851         if (!NT_STATUS_IS_OK(status)) {
 852                 TALLOC_FREE(array);
 853                 return;
 854         }
 855
 856         blob.data = (uint8 *)dbuf.dptr;
 857         blob.length = dbuf.dsize;
 858
 859         if (blob.length > 0) {
 860                 enum ndr_err_code ndr_err;
 861                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 862                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 863                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 864                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 865                                    ndr_errstr(ndr_err)));
 866                         TALLOC_FREE(array);
 867                         return;
 868                 }
 869                 if (DEBUGLEVEL >= 10) {
 870                         DEBUG(10, ("notify_onelevel:\n"));
 871                         NDR_PRINT_DEBUG(notify_entry_array, array);
 872                 }
 873         }
 874
 875         for (i=0; i<array->num_entries; i++) {
 876                 struct notify_entry *e = &array->entries[i];
 877
 878                 if ((e->filter & filter) != 0) {
 879                         status = notify_send(notify, e, name, action);
 880                         if (NT_STATUS_EQUAL(
 881                                     status, NT_STATUS_INVALID_HANDLE)) {
 882                                 /*
 883                                  * Mark the entry as dead. All entries have a
 884                                  * path set. The marker used here is setting
 885                                  * that to NULL.
 886                                  */
 887                                 e->path = NULL;
 888                                 have_dead_entries = true;
 889                         }
 890                 }
 891         }
 892
 893         if (!have_dead_entries) {
 894                 TALLOC_FREE(array);
 895                 return;
 896         }
 897
 898         for (i=0; i<array->num_entries; i++) {
 899                 struct notify_entry *e = &array->entries[i];
 900                 if (e->path != NULL) {
 901                         continue;
 902                 }
 903                 DEBUG(10, ("Deleting notify entries for process %s because "
 904                            "it's gone\n", procid_str_static(&e->server)));
 905                 /*
 906                  * Potential TODO: This might need optimizing,
 907                  * notify_remove_onelevel() does a fetch_locked() operation at
 908                  * every call. But this would only matter if a process with
 909                  * MANY notifies has died without shutting down properly.
 910                  */
 911                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 912         }
 913
 914         TALLOC_FREE(array);
 915         return;
 916 }
 917
 918 /*
 919   trigger a notify message for anyone waiting on a matching event
 920
 921   This function is called a lot, and needs to be very fast. The unusual data structure
 922   and traversal is designed to be fast in the average case, even for large numbers of
 923   notifies
 924 */
 925 void notify_trigger(struct notify_context *notify,
 926                     uint32_t action, uint32_t filter, const char *path)
 927 {
 928         NTSTATUS status;
 929         int depth;
 930         const char *p, *next_p;
 931
 932         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 933                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 934
 935         /* see if change notify is enabled at all */
 936         if (notify == NULL) {
 937                 return;
 938         }
 939
 940  again:
 941         status = notify_load(notify, NULL);
 942         if (!NT_STATUS_IS_OK(status)) {
 943                 return;
 944         }
 945
 946         /* loop along the given path, working with each directory depth separately */
 947         for (depth=0,p=path;
 948              p && depth < notify->array->num_depths;
 949              p=next_p,depth++) {
 950                 int p_len = p - path;
 951                 int min_i, max_i, i;
 952                 struct notify_depth *d = &notify->array->depth[depth];
 953                 next_p = strchr(p+1, '/');
 954
 955                 /* see if there are any entries at this depth */
 956                 if (d->num_entries == 0) continue;
 957
 958                 /* try to skip based on the maximum mask. If next_p is
 959                  NULL then we know it will be a 'this directory'
 960                  match, otherwise it must be a subdir match */
 961                 if (next_p != NULL) {
 962                         if (0 == (filter & d->max_mask_subdir)) {
 963                                 continue;
 964                         }
 965                 } else {
 966                         if (0 == (filter & d->max_mask)) {
 967                                 continue;
 968                         }
 969                 }
 970
 971                 /* we know there is an entry here worth looking
 972                  for. Use a bisection search to find the first entry
 973                  with a matching path */
 974                 min_i = 0;
 975                 max_i = d->num_entries-1;
 976
 977                 while (min_i < max_i) {
 978                         struct notify_entry *e;
 979                         int cmp;
 980                         i = (min_i+max_i)/2;
 981                         e = &d->entries[i];
 982                         cmp = strncmp(path, e->path, p_len);
 983                         if (cmp == 0) {
 984                                 if (p_len == e->path_len) {
 985                                         max_i = i;
 986                                 } else {
 987                                         max_i = i-1;
 988                                 }
 989                         } else if (cmp < 0) {
 990                                 max_i = i-1;
 991                         } else {
 992                                 min_i = i+1;
 993                         }
 994                 }
 995
 996                 if (min_i != max_i) {
 997                         /* none match */
 998                         continue;
 999                 }
1000
1001                 /* we now know that the entries start at min_i */
1002                 for (i=min_i;i<d->num_entries;i++) {
1003                         struct notify_entry *e = &d->entries[i];
1004                         if (p_len != e->path_len ||
1005                             strncmp(path, e->path, p_len) != 0) break;
1006                         if (next_p != NULL) {
1007                                 if (0 == (filter & e->subdir_filter)) {
1008                                         continue;
1009                                 }
1010                         } else {
1011                                 if (0 == (filter & e->filter)) {
1012                                         continue;
1013                                 }
1014                         }
1015                         status = notify_send(notify, e, path + e->path_len + 1,
1016                                              action);
1017
1018                         if (NT_STATUS_EQUAL(
1019                                     status, NT_STATUS_INVALID_HANDLE)) {
1020                                 struct server_id server = e->server;
1021
1022                                 DEBUG(10, ("Deleting notify entries for "
1023                                            "process %s because it's gone\n",
1024                                            procid_str_static(&e->server)));
1025                                 notify_remove_all(notify, &server);
1026                                 goto again;
1027                         }
1028                 }
1029         }
1030 }