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 #include "lib/param/param.h"
  36
  37 struct notify_context {
  38         struct db_context *db_recursive;
  39         struct db_context *db_onelevel;
  40         struct server_id server;
  41         struct messaging_context *messaging_ctx;
  42         struct notify_list *list;
  43         struct notify_array *array;
  44         int seqnum;
  45         struct sys_notify_context *sys_notify_ctx;
  46         TDB_DATA key;
  47 };
  48
  49
  50 struct notify_list {
  51         struct notify_list *next, *prev;
  52         void *private_data;
  53         void (*callback)(void *, const struct notify_event *);
  54         void *sys_notify_handle;
  55         int depth;
  56 };
  57
  58 #define NOTIFY_KEY "notify array"
  59
  60 #define NOTIFY_ENABLE           "notify:enable"
  61 #define NOTIFY_ENABLE_DEFAULT   True
  62
  63 static NTSTATUS notify_remove_all(struct notify_context *notify,
  64                                   const struct server_id *server);
  65 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
  66                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
  67
  68 /*
  69   destroy the notify context
  70 */
  71 static int notify_destructor(struct notify_context *notify)
  72 {
  73         messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
  74
  75         if (notify->list != NULL) {
  76                 notify_remove_all(notify, &notify->server);
  77         }
  78
  79         return 0;
  80 }
  81
  82 /*
  83   Open up the notify.tdb database. You should close it down using
  84   talloc_free(). We need the messaging_ctx to allow for notifications
  85   via internal messages
  86 */
  87 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
  88                                    struct messaging_context *messaging_ctx,
  89                                    struct event_context *ev,
  90                                    connection_struct *conn)
  91 {
  92         struct notify_context *notify;
  93
  94         if (!lp_change_notify(conn->params)) {
  95                 return NULL;
  96         }
  97
  98         notify = talloc(mem_ctx, struct notify_context);
  99         if (notify == NULL) {
 100                 return NULL;
 101         }
 102
 103         notify->db_recursive = db_open(notify, lock_path("notify.tdb"),
 104                                        0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 105                                        O_RDWR|O_CREAT, 0644,
 106                                        DBWRAP_LOCK_ORDER_2);
 107         if (notify->db_recursive == NULL) {
 108                 talloc_free(notify);
 109                 return NULL;
 110         }
 111
 112         notify->db_onelevel = db_open(notify, lock_path("notify_onelevel.tdb"),
 113                                       0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 114                                       O_RDWR|O_CREAT, 0644,
 115                                       DBWRAP_LOCK_ORDER_2);
 116         if (notify->db_onelevel == NULL) {
 117                 talloc_free(notify);
 118                 return NULL;
 119         }
 120
 121         notify->server = server;
 122         notify->messaging_ctx = messaging_ctx;
 123         notify->list = NULL;
 124         notify->array = NULL;
 125         notify->seqnum = dbwrap_get_seqnum(notify->db_recursive);
 126         notify->key = string_term_tdb_data(NOTIFY_KEY);
 127
 128         talloc_set_destructor(notify, notify_destructor);
 129
 130         /* register with the messaging subsystem for the notify
 131            message type */
 132         messaging_register(notify->messaging_ctx, notify,
 133                            MSG_PVFS_NOTIFY, notify_handler);
 134
 135         notify->sys_notify_ctx = sys_notify_context_create(conn, notify, ev);
 136
 137         return notify;
 138 }
 139
 140 bool notify_internal_parent_init(TALLOC_CTX *mem_ctx)
 141 {
 142         struct tdb_wrap *db1, *db2;
 143         struct loadparm_context *lp_ctx;
 144
 145         if (lp_clustering()) {
 146                 return true;
 147         }
 148
 149         lp_ctx = loadparm_init_s3(mem_ctx, loadparm_s3_context());
 150         if (lp_ctx == NULL) {
 151                 DEBUG(0, ("loadparm_init_s3 failed\n"));
 152                 return false;
 153         }
 154         /*
 155          * Open the tdbs in the parent process (smbd) so that our
 156          * CLEAR_IF_FIRST optimization in tdb_reopen_all can properly
 157          * work.
 158          */
 159
 160         db1 = tdb_wrap_open(mem_ctx, lock_path("notify.tdb"),
 161                             0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 162                             O_RDWR|O_CREAT, 0644, lp_ctx);
 163         if (db1 == NULL) {
 164                 talloc_unlink(mem_ctx, lp_ctx);
 165                 DEBUG(1, ("could not open notify.tdb: %s\n", strerror(errno)));
 166                 return false;
 167         }
 168         db2 = tdb_wrap_open(mem_ctx, lock_path("notify_onelevel.tdb"),
 169                             0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDWR|O_CREAT, 0644, lp_ctx);
 170         talloc_unlink(mem_ctx, lp_ctx);
 171         if (db2 == NULL) {
 172                 DEBUG(1, ("could not open notify_onelevel.tdb: %s\n",
 173                           strerror(errno)));
 174                 TALLOC_FREE(db1);
 175                 return false;
 176         }
 177         return true;
 178 }
 179
 180 /*
 181   lock and fetch the record
 182 */
 183 static NTSTATUS notify_fetch_locked(struct notify_context *notify, struct db_record **rec)
 184 {
 185         *rec = dbwrap_fetch_locked(notify->db_recursive, notify, notify->key);
 186         if (*rec == NULL) {
 187                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 188         }
 189         return NT_STATUS_OK;
 190 }
 191
 192 /*
 193   load the notify array
 194 */
 195 static NTSTATUS notify_load(struct notify_context *notify, struct db_record *rec)
 196 {
 197         TDB_DATA dbuf;
 198         DATA_BLOB blob;
 199         NTSTATUS status;
 200         int seqnum;
 201
 202         seqnum = dbwrap_get_seqnum(notify->db_recursive);
 203
 204         if (seqnum == notify->seqnum && notify->array != NULL) {
 205                 return NT_STATUS_OK;
 206         }
 207
 208         notify->seqnum = seqnum;
 209
 210         talloc_free(notify->array);
 211         notify->array = talloc_zero(notify, struct notify_array);
 212         NT_STATUS_HAVE_NO_MEMORY(notify->array);
 213
 214         if (!rec) {
 215                 status = dbwrap_fetch(notify->db_recursive, notify,
 216                                       notify->key, &dbuf);
 217                 if (!NT_STATUS_IS_OK(status)) {
 218                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 219                 }
 220         } else {
 221                 dbuf = dbwrap_record_get_value(rec);
 222         }
 223
 224         blob.data = (uint8 *)dbuf.dptr;
 225         blob.length = dbuf.dsize;
 226
 227         status = NT_STATUS_OK;
 228         if (blob.length > 0) {
 229                 enum ndr_err_code ndr_err;
 230                 ndr_err = ndr_pull_struct_blob(&blob, notify->array, notify->array,
 231                                                (ndr_pull_flags_fn_t)ndr_pull_notify_array);
 232                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 233                         /* 1. log that we got a corrupt notify_array
 234                          * 2. clear the variable the garbage was stored into to not trip
 235                          *  over it next time this method is entered with the same seqnum
 236                          * 3. delete it from the database */
 237                         DEBUG(2, ("notify_array is corrupt, discarding it\n"));
 238
 239                         ZERO_STRUCTP(notify->array);
 240                         if (rec != NULL) {
 241                                 dbwrap_record_delete(rec);
 242                         }
 243
 244                 } else {
 245                         if (DEBUGLEVEL >= 10) {
 246                                 DEBUG(10, ("notify_load:\n"));
 247                                 NDR_PRINT_DEBUG(notify_array, notify->array);
 248                         }
 249                 }
 250         }
 251
 252
 253         if (!rec) {
 254                 talloc_free(dbuf.dptr);
 255         }
 256
 257         return status;
 258 }
 259
 260 /*
 261   compare notify entries for sorting
 262 */
 263 static int notify_compare(const struct notify_entry *e1, const struct notify_entry *e2)
 264 {
 265         return strcmp(e1->path, e2->path);
 266 }
 267
 268 /*
 269   save the notify array
 270 */
 271 static NTSTATUS notify_save(struct notify_context *notify, struct db_record *rec)
 272 {
 273         TDB_DATA dbuf;
 274         DATA_BLOB blob;
 275         NTSTATUS status;
 276         enum ndr_err_code ndr_err;
 277         TALLOC_CTX *tmp_ctx;
 278
 279         /* if possible, remove some depth arrays */
 280         while (notify->array->num_depths > 0 &&
 281                notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
 282                 notify->array->num_depths--;
 283         }
 284
 285         /* we might just be able to delete the record */
 286         if (notify->array->num_depths == 0) {
 287                 return dbwrap_record_delete(rec);
 288         }
 289
 290         tmp_ctx = talloc_new(notify);
 291         NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
 292
 293         ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, notify->array,
 294                                       (ndr_push_flags_fn_t)ndr_push_notify_array);
 295         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 296                 talloc_free(tmp_ctx);
 297                 return ndr_map_error2ntstatus(ndr_err);
 298         }
 299
 300         if (DEBUGLEVEL >= 10) {
 301                 DEBUG(10, ("notify_save:\n"));
 302                 NDR_PRINT_DEBUG(notify_array, notify->array);
 303         }
 304
 305         dbuf.dptr = blob.data;
 306         dbuf.dsize = blob.length;
 307
 308         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 309         talloc_free(tmp_ctx);
 310
 311         return status;
 312 }
 313
 314
 315 /*
 316   handle incoming notify messages
 317 */
 318 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
 319                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
 320 {
 321         struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
 322         enum ndr_err_code ndr_err;
 323         struct notify_event ev;
 324         TALLOC_CTX *tmp_ctx = talloc_new(notify);
 325         struct notify_list *listel;
 326
 327         if (tmp_ctx == NULL) {
 328                 return;
 329         }
 330
 331         ndr_err = ndr_pull_struct_blob(data, tmp_ctx, &ev,
 332                                        (ndr_pull_flags_fn_t)ndr_pull_notify_event);
 333         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 334                 talloc_free(tmp_ctx);
 335                 return;
 336         }
 337
 338         for (listel=notify->list;listel;listel=listel->next) {
 339                 if (listel->private_data == ev.private_data) {
 340                         listel->callback(listel->private_data, &ev);
 341                         break;
 342                 }
 343         }
 344
 345         talloc_free(tmp_ctx);
 346 }
 347
 348 /*
 349   callback from sys_notify telling us about changes from the OS
 350 */
 351 static void sys_notify_callback(struct sys_notify_context *ctx,
 352                                 void *ptr, struct notify_event *ev)
 353 {
 354         struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
 355         ev->private_data = listel;
 356         DEBUG(10, ("sys_notify_callback called with action=%d, for %s\n",
 357                    ev->action, ev->path));
 358         listel->callback(listel->private_data, ev);
 359 }
 360
 361 /*
 362   add an entry to the notify array
 363 */
 364 static NTSTATUS notify_add_array(struct notify_context *notify, struct db_record *rec,
 365                                  struct notify_entry *e,
 366                                  void *private_data, int depth)
 367 {
 368         int i;
 369         struct notify_depth *d;
 370         struct notify_entry *ee;
 371
 372         /* possibly expand the depths array */
 373         if (depth >= notify->array->num_depths) {
 374                 d = talloc_realloc(notify->array, notify->array->depth,
 375                                    struct notify_depth, depth+1);
 376                 NT_STATUS_HAVE_NO_MEMORY(d);
 377                 for (i=notify->array->num_depths;i<=depth;i++) {
 378                         ZERO_STRUCT(d[i]);
 379                 }
 380                 notify->array->depth = d;
 381                 notify->array->num_depths = depth+1;
 382         }
 383         d = &notify->array->depth[depth];
 384
 385         /* expand the entries array */
 386         ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
 387                             d->num_entries+1);
 388         NT_STATUS_HAVE_NO_MEMORY(ee);
 389         d->entries = ee;
 390
 391         d->entries[d->num_entries] = *e;
 392         d->entries[d->num_entries].private_data = private_data;
 393         d->entries[d->num_entries].server = notify->server;
 394         d->entries[d->num_entries].path_len = strlen(e->path);
 395         d->num_entries++;
 396
 397         d->max_mask |= e->filter;
 398         d->max_mask_subdir |= e->subdir_filter;
 399
 400         TYPESAFE_QSORT(d->entries, d->num_entries, notify_compare);
 401
 402         /* recalculate the maximum masks */
 403         d->max_mask = 0;
 404         d->max_mask_subdir = 0;
 405
 406         for (i=0;i<d->num_entries;i++) {
 407                 d->max_mask |= d->entries[i].filter;
 408                 d->max_mask_subdir |= d->entries[i].subdir_filter;
 409         }
 410
 411         return notify_save(notify, rec);
 412 }
 413
 414 /*
 415   Add a non-recursive watch
 416 */
 417
 418 static void notify_add_onelevel(struct notify_context *notify,
 419                                 struct notify_entry *e, void *private_data)
 420 {
 421         struct notify_entry_array *array;
 422         struct db_record *rec;
 423         DATA_BLOB blob;
 424         TDB_DATA dbuf;
 425         TDB_DATA value;
 426         enum ndr_err_code ndr_err;
 427         NTSTATUS status;
 428
 429         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 430         if (array == NULL) {
 431                 return;
 432         }
 433
 434         rec = dbwrap_fetch_locked(notify->db_onelevel, talloc_tos(),
 435                                   make_tdb_data((uint8_t *)&e->dir_id,
 436                                    sizeof(e->dir_id)));
 437         if (rec == NULL) {
 438                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 439                            "\n", file_id_string_tos(&e->dir_id)));
 440                 TALLOC_FREE(array);
 441                 return;
 442         }
 443
 444         value = dbwrap_record_get_value(rec);
 445         blob.data = (uint8_t *)value.dptr;
 446         blob.length = value.dsize;
 447
 448         if (blob.length > 0) {
 449                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 450                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 451                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 452                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 453                                    ndr_errstr(ndr_err)));
 454                         TALLOC_FREE(array);
 455                         return;
 456                 }
 457                 if (DEBUGLEVEL >= 10) {
 458                         DEBUG(10, ("notify_add_onelevel:\n"));
 459                         NDR_PRINT_DEBUG(notify_entry_array, array);
 460                 }
 461         }
 462
 463         array->entries = talloc_realloc(array, array->entries,
 464                                         struct notify_entry,
 465                                         array->num_entries+1);
 466         if (array->entries == NULL) {
 467                 TALLOC_FREE(array);
 468                 return;
 469         }
 470         array->entries[array->num_entries] = *e;
 471         array->entries[array->num_entries].private_data = private_data;
 472         array->entries[array->num_entries].server = notify->server;
 473         array->num_entries += 1;
 474
 475         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 476                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 477         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 478                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 479                            ndr_errstr(ndr_err)));
 480                 TALLOC_FREE(array);
 481                 return;
 482         }
 483
 484         if (DEBUGLEVEL >= 10) {
 485                 DEBUG(10, ("notify_add_onelevel:\n"));
 486                 NDR_PRINT_DEBUG(notify_entry_array, array);
 487         }
 488
 489         dbuf.dptr = blob.data;
 490         dbuf.dsize = blob.length;
 491
 492         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 493         TALLOC_FREE(array);
 494         if (!NT_STATUS_IS_OK(status)) {
 495                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 496                            nt_errstr(status)));
 497                 return;
 498         }
 499         e->filter = 0;
 500         return;
 501 }
 502
 503
 504 /*
 505   add a notify watch. This is called when a notify is first setup on a open
 506   directory handle.
 507 */
 508 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 509                     void (*callback)(void *, const struct notify_event *),
 510                     void *private_data)
 511 {
 512         struct notify_entry e = *e0;
 513         NTSTATUS status;
 514         char *tmp_path = NULL;
 515         struct notify_list *listel;
 516         size_t len;
 517         int depth;
 518         struct db_record *rec;
 519
 520         /* see if change notify is enabled at all */
 521         if (notify == NULL) {
 522                 return NT_STATUS_NOT_IMPLEMENTED;
 523         }
 524
 525         status = notify_fetch_locked(notify, &rec);
 526         NT_STATUS_NOT_OK_RETURN(status);
 527
 528         status = notify_load(notify, rec);
 529         if (!NT_STATUS_IS_OK(status)) {
 530                 talloc_free(rec);
 531                 return status;
 532         }
 533
 534         /* cope with /. on the end of the path */
 535         len = strlen(e.path);
 536         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 537                 tmp_path = talloc_strndup(notify, e.path, len-2);
 538                 if (tmp_path == NULL) {
 539                         status = NT_STATUS_NO_MEMORY;
 540                         goto done;
 541                 }
 542                 e.path = tmp_path;
 543         }
 544
 545         depth = count_chars(e.path, '/');
 546
 547         listel = talloc_zero(notify, struct notify_list);
 548         if (listel == NULL) {
 549                 status = NT_STATUS_NO_MEMORY;
 550                 goto done;
 551         }
 552
 553         listel->private_data = private_data;
 554         listel->callback = callback;
 555         listel->depth = depth;
 556         DLIST_ADD(notify->list, listel);
 557
 558         /* ignore failures from sys_notify */
 559         if (notify->sys_notify_ctx != NULL) {
 560                 /*
 561                   this call will modify e.filter and e.subdir_filter
 562                   to remove bits handled by the backend
 563                 */
 564                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 565                                           sys_notify_callback, listel,
 566                                           &listel->sys_notify_handle);
 567                 if (NT_STATUS_IS_OK(status)) {
 568                         talloc_steal(listel, listel->sys_notify_handle);
 569                 }
 570         }
 571
 572         if (e.filter != 0) {
 573                 notify_add_onelevel(notify, &e, private_data);
 574                 status = NT_STATUS_OK;
 575         }
 576
 577         /* if the system notify handler couldn't handle some of the
 578            filter bits, or couldn't handle a request for recursion
 579            then we need to install it in the array used for the
 580            intra-samba notify handling */
 581         if (e.filter != 0 || e.subdir_filter != 0) {
 582                 status = notify_add_array(notify, rec, &e, private_data, depth);
 583         }
 584
 585 done:
 586         talloc_free(rec);
 587         talloc_free(tmp_path);
 588
 589         return status;
 590 }
 591
 592 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 593                                 const struct file_id *fid,
 594                                 void *private_data)
 595 {
 596         struct notify_entry_array *array;
 597         struct db_record *rec;
 598         DATA_BLOB blob;
 599         TDB_DATA dbuf;
 600         TDB_DATA value;
 601         enum ndr_err_code ndr_err;
 602         NTSTATUS status;
 603         int i;
 604
 605         if (notify == NULL) {
 606                 return NT_STATUS_NOT_IMPLEMENTED;
 607         }
 608
 609         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 610         if (array == NULL) {
 611                 return NT_STATUS_NO_MEMORY;
 612         }
 613
 614         rec = dbwrap_fetch_locked(
 615                 notify->db_onelevel, array,
 616                 make_tdb_data((const uint8_t *)fid, sizeof(*fid)));
 617         if (rec == NULL) {
 618                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 619                            "\n", file_id_string_tos(fid)));
 620                 TALLOC_FREE(array);
 621                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 622         }
 623
 624         value = dbwrap_record_get_value(rec);
 625         blob.data = (uint8_t *)value.dptr;
 626         blob.length = value.dsize;
 627
 628         if (blob.length > 0) {
 629                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 630                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 631                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 632                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 633                                    ndr_errstr(ndr_err)));
 634                         TALLOC_FREE(array);
 635                         return ndr_map_error2ntstatus(ndr_err);
 636                 }
 637                 if (DEBUGLEVEL >= 10) {
 638                         DEBUG(10, ("notify_remove_onelevel:\n"));
 639                         NDR_PRINT_DEBUG(notify_entry_array, array);
 640                 }
 641         }
 642
 643         for (i=0; i<array->num_entries; i++) {
 644                 if ((private_data == array->entries[i].private_data) &&
 645                     cluster_id_equal(&notify->server,
 646                                      &array->entries[i].server)) {
 647                         break;
 648                 }
 649         }
 650
 651         if (i == array->num_entries) {
 652                 TALLOC_FREE(array);
 653                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 654         }
 655
 656         array->entries[i] = array->entries[array->num_entries-1];
 657         array->num_entries -= 1;
 658
 659         if (array->num_entries == 0) {
 660                 dbwrap_record_delete(rec);
 661                 TALLOC_FREE(array);
 662                 return NT_STATUS_OK;
 663         }
 664
 665         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 666                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 667         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 668                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 669                            ndr_errstr(ndr_err)));
 670                 TALLOC_FREE(array);
 671                 return ndr_map_error2ntstatus(ndr_err);
 672         }
 673
 674         if (DEBUGLEVEL >= 10) {
 675                 DEBUG(10, ("notify_add_onelevel:\n"));
 676                 NDR_PRINT_DEBUG(notify_entry_array, array);
 677         }
 678
 679         dbuf.dptr = blob.data;
 680         dbuf.dsize = blob.length;
 681
 682         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 683         TALLOC_FREE(array);
 684         if (!NT_STATUS_IS_OK(status)) {
 685                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 686                            nt_errstr(status)));
 687                 return status;
 688         }
 689         return NT_STATUS_OK;
 690 }
 691
 692 /*
 693   remove a notify watch. Called when the directory handle is closed
 694 */
 695 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 696 {
 697         NTSTATUS status;
 698         struct notify_list *listel;
 699         int i, depth;
 700         struct notify_depth *d;
 701         struct db_record *rec;
 702
 703         /* see if change notify is enabled at all */
 704         if (notify == NULL) {
 705                 return NT_STATUS_NOT_IMPLEMENTED;
 706         }
 707
 708         for (listel=notify->list;listel;listel=listel->next) {
 709                 if (listel->private_data == private_data) {
 710                         DLIST_REMOVE(notify->list, listel);
 711                         break;
 712                 }
 713         }
 714         if (listel == NULL) {
 715                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 716         }
 717
 718         depth = listel->depth;
 719
 720         talloc_free(listel);
 721
 722         status = notify_fetch_locked(notify, &rec);
 723         NT_STATUS_NOT_OK_RETURN(status);
 724
 725         status = notify_load(notify, rec);
 726         if (!NT_STATUS_IS_OK(status)) {
 727                 talloc_free(rec);
 728                 return status;
 729         }
 730
 731         if (depth >= notify->array->num_depths) {
 732                 talloc_free(rec);
 733                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 734         }
 735
 736         /* we only have to search at the depth of this element */
 737         d = &notify->array->depth[depth];
 738
 739         for (i=0;i<d->num_entries;i++) {
 740                 if (private_data == d->entries[i].private_data &&
 741                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 742                         break;
 743                 }
 744         }
 745         if (i == d->num_entries) {
 746                 talloc_free(rec);
 747                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 748         }
 749
 750         if (i < d->num_entries-1) {
 751                 memmove(&d->entries[i], &d->entries[i+1],
 752                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 753         }
 754         d->num_entries--;
 755
 756         status = notify_save(notify, rec);
 757
 758         talloc_free(rec);
 759
 760         return status;
 761 }
 762
 763 /*
 764   remove all notify watches for a messaging server
 765 */
 766 static NTSTATUS notify_remove_all(struct notify_context *notify,
 767                                   const struct server_id *server)
 768 {
 769         NTSTATUS status;
 770         int i, depth, del_count=0;
 771         struct db_record *rec;
 772
 773         status = notify_fetch_locked(notify, &rec);
 774         NT_STATUS_NOT_OK_RETURN(status);
 775
 776         status = notify_load(notify, rec);
 777         if (!NT_STATUS_IS_OK(status)) {
 778                 talloc_free(rec);
 779                 return status;
 780         }
 781
 782         /* we have to search for all entries across all depths, looking for matches
 783            for the server id */
 784         for (depth=0;depth<notify->array->num_depths;depth++) {
 785                 struct notify_depth *d = &notify->array->depth[depth];
 786                 for (i=0;i<d->num_entries;i++) {
 787                         if (cluster_id_equal(server, &d->entries[i].server)) {
 788                                 if (i < d->num_entries-1) {
 789                                         memmove(&d->entries[i], &d->entries[i+1],
 790                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 791                                 }
 792                                 i--;
 793                                 d->num_entries--;
 794                                 del_count++;
 795                         }
 796                 }
 797         }
 798
 799         if (del_count > 0) {
 800                 status = notify_save(notify, rec);
 801         }
 802
 803         talloc_free(rec);
 804
 805         return status;
 806 }
 807
 808
 809 /*
 810   send a notify message to another messaging server
 811 */
 812 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 813                             const char *path, uint32_t action)
 814 {
 815         struct notify_event ev;
 816         DATA_BLOB data;
 817         NTSTATUS status;
 818         enum ndr_err_code ndr_err;
 819         TALLOC_CTX *tmp_ctx;
 820
 821         ev.action = action;
 822         ev.path = path;
 823         ev.private_data = e->private_data;
 824
 825         tmp_ctx = talloc_new(notify);
 826
 827         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, &ev,
 828                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 829         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 830                 talloc_free(tmp_ctx);
 831                 return ndr_map_error2ntstatus(ndr_err);
 832         }
 833
 834         status = messaging_send(notify->messaging_ctx, e->server,
 835                                 MSG_PVFS_NOTIFY, &data);
 836         talloc_free(tmp_ctx);
 837         return status;
 838 }
 839
 840 void notify_onelevel(struct notify_context *notify, uint32_t action,
 841                      uint32_t filter, struct file_id fid, const char *name)
 842 {
 843         struct notify_entry_array *array;
 844         TDB_DATA dbuf;
 845         DATA_BLOB blob;
 846         bool have_dead_entries = false;
 847         int i;
 848         NTSTATUS status;
 849
 850         if (notify == NULL) {
 851                 return;
 852         }
 853
 854         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 855         if (array == NULL) {
 856                 return;
 857         }
 858
 859         status = dbwrap_fetch(notify->db_onelevel, array,
 860                               make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 861                               &dbuf);
 862         if (!NT_STATUS_IS_OK(status)) {
 863                 TALLOC_FREE(array);
 864                 return;
 865         }
 866
 867         blob.data = (uint8 *)dbuf.dptr;
 868         blob.length = dbuf.dsize;
 869
 870         if (blob.length > 0) {
 871                 enum ndr_err_code ndr_err;
 872                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 873                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 874                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 875                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 876                                    ndr_errstr(ndr_err)));
 877                         TALLOC_FREE(array);
 878                         return;
 879                 }
 880                 if (DEBUGLEVEL >= 10) {
 881                         DEBUG(10, ("notify_onelevel:\n"));
 882                         NDR_PRINT_DEBUG(notify_entry_array, array);
 883                 }
 884         }
 885
 886         for (i=0; i<array->num_entries; i++) {
 887                 struct notify_entry *e = &array->entries[i];
 888
 889                 if ((e->filter & filter) != 0) {
 890                         status = notify_send(notify, e, name, action);
 891                         if (NT_STATUS_EQUAL(
 892                                     status, NT_STATUS_INVALID_HANDLE)) {
 893                                 /*
 894                                  * Mark the entry as dead. All entries have a
 895                                  * path set. The marker used here is setting
 896                                  * that to NULL.
 897                                  */
 898                                 e->path = NULL;
 899                                 have_dead_entries = true;
 900                         }
 901                 }
 902         }
 903
 904         if (!have_dead_entries) {
 905                 TALLOC_FREE(array);
 906                 return;
 907         }
 908
 909         for (i=0; i<array->num_entries; i++) {
 910                 struct notify_entry *e = &array->entries[i];
 911                 if (e->path != NULL) {
 912                         continue;
 913                 }
 914                 DEBUG(10, ("Deleting notify entries for process %s because "
 915                            "it's gone\n", procid_str_static(&e->server)));
 916                 /*
 917                  * Potential TODO: This might need optimizing,
 918                  * notify_remove_onelevel() does a fetch_locked() operation at
 919                  * every call. But this would only matter if a process with
 920                  * MANY notifies has died without shutting down properly.
 921                  */
 922                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 923         }
 924
 925         TALLOC_FREE(array);
 926         return;
 927 }
 928
 929 /*
 930   trigger a notify message for anyone waiting on a matching event
 931
 932   This function is called a lot, and needs to be very fast. The unusual data structure
 933   and traversal is designed to be fast in the average case, even for large numbers of
 934   notifies
 935 */
 936 void notify_trigger(struct notify_context *notify,
 937                     uint32_t action, uint32_t filter, const char *path)
 938 {
 939         NTSTATUS status;
 940         int depth;
 941         const char *p, *next_p;
 942
 943         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 944                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 945
 946         /* see if change notify is enabled at all */
 947         if (notify == NULL) {
 948                 return;
 949         }
 950
 951  again:
 952         status = notify_load(notify, NULL);
 953         if (!NT_STATUS_IS_OK(status)) {
 954                 return;
 955         }
 956
 957         /* loop along the given path, working with each directory depth separately */
 958         for (depth=0,p=path;
 959              p && depth < notify->array->num_depths;
 960              p=next_p,depth++) {
 961                 int p_len = p - path;
 962                 int min_i, max_i, i;
 963                 struct notify_depth *d = &notify->array->depth[depth];
 964                 next_p = strchr(p+1, '/');
 965
 966                 /* see if there are any entries at this depth */
 967                 if (d->num_entries == 0) continue;
 968
 969                 /* try to skip based on the maximum mask. If next_p is
 970                  NULL then we know it will be a 'this directory'
 971                  match, otherwise it must be a subdir match */
 972                 if (next_p != NULL) {
 973                         if (0 == (filter & d->max_mask_subdir)) {
 974                                 continue;
 975                         }
 976                 } else {
 977                         if (0 == (filter & d->max_mask)) {
 978                                 continue;
 979                         }
 980                 }
 981
 982                 /* we know there is an entry here worth looking
 983                  for. Use a bisection search to find the first entry
 984                  with a matching path */
 985                 min_i = 0;
 986                 max_i = d->num_entries-1;
 987
 988                 while (min_i < max_i) {
 989                         struct notify_entry *e;
 990                         int cmp;
 991                         i = (min_i+max_i)/2;
 992                         e = &d->entries[i];
 993                         cmp = strncmp(path, e->path, p_len);
 994                         if (cmp == 0) {
 995                                 if (p_len == e->path_len) {
 996                                         max_i = i;
 997                                 } else {
 998                                         max_i = i-1;
 999                                 }
1000                         } else if (cmp < 0) {
1001                                 max_i = i-1;
1002                         } else {
1003                                 min_i = i+1;
1004                         }
1005                 }
1006
1007                 if (min_i != max_i) {
1008                         /* none match */
1009                         continue;
1010                 }
1011
1012                 /* we now know that the entries start at min_i */
1013                 for (i=min_i;i<d->num_entries;i++) {
1014                         struct notify_entry *e = &d->entries[i];
1015                         if (p_len != e->path_len ||
1016                             strncmp(path, e->path, p_len) != 0) break;
1017                         if (next_p != NULL) {
1018                                 if (0 == (filter & e->subdir_filter)) {
1019                                         continue;
1020                                 }
1021                         } else {
1022                                 if (0 == (filter & e->filter)) {
1023                                         continue;
1024                                 }
1025                         }
1026                         status = notify_send(notify, e, path + e->path_len + 1,
1027                                              action);
1028
1029                         if (NT_STATUS_EQUAL(
1030                                     status, NT_STATUS_INVALID_HANDLE)) {
1031                                 struct server_id server = e->server;
1032
1033                                 DEBUG(10, ("Deleting notify entries for "
1034                                            "process %s because it's gone\n",
1035                                            procid_str_static(&e->server)));
1036                                 notify_remove_all(notify, &server);
1037                                 goto again;
1038                         }
1039                 }
1040         }
1041 }