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/tdb_wrap/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,
  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 = messaging_server_id(messaging_ctx);
 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, array,
 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         struct notify_list *listel;
 515         int depth;
 516
 517         /* see if change notify is enabled at all */
 518         if (notify == NULL) {
 519                 return NT_STATUS_NOT_IMPLEMENTED;
 520         }
 521
 522         depth = count_chars(e.path, '/');
 523
 524         listel = talloc_zero(notify, struct notify_list);
 525         if (listel == NULL) {
 526                 status = NT_STATUS_NO_MEMORY;
 527                 goto done;
 528         }
 529
 530         listel->private_data = private_data;
 531         listel->callback = callback;
 532         listel->depth = depth;
 533         DLIST_ADD(notify->list, listel);
 534
 535         /* ignore failures from sys_notify */
 536         if (notify->sys_notify_ctx != NULL) {
 537                 /*
 538                   this call will modify e.filter and e.subdir_filter
 539                   to remove bits handled by the backend
 540                 */
 541                 status = sys_notify_watch(notify->sys_notify_ctx, &e, e.path,
 542                                           sys_notify_callback, listel,
 543                                           &listel->sys_notify_handle);
 544                 if (NT_STATUS_IS_OK(status)) {
 545                         talloc_steal(listel, listel->sys_notify_handle);
 546                 }
 547         }
 548
 549         if (e.filter != 0) {
 550                 notify_add_onelevel(notify, &e, private_data);
 551                 status = NT_STATUS_OK;
 552         }
 553
 554         /* if the system notify handler couldn't handle some of the
 555            filter bits, or couldn't handle a request for recursion
 556            then we need to install it in the array used for the
 557            intra-samba notify handling */
 558         if (e.filter != 0 || e.subdir_filter != 0) {
 559                 struct db_record *rec;
 560
 561                 status = notify_fetch_locked(notify, &rec);
 562                 if (!NT_STATUS_IS_OK(status)) {
 563                         goto done;
 564                 }
 565                 status = notify_load(notify, rec);
 566                 if (!NT_STATUS_IS_OK(status)) {
 567                         TALLOC_FREE(rec);
 568                         goto done;
 569                 }
 570                 status = notify_add_array(notify, rec, &e, private_data,
 571                                           depth);
 572                 TALLOC_FREE(rec);
 573         }
 574         status = NT_STATUS_OK;
 575 done:
 576         return status;
 577 }
 578
 579 NTSTATUS notify_remove_onelevel(struct notify_context *notify,
 580                                 const struct file_id *fid,
 581                                 void *private_data)
 582 {
 583         struct notify_entry_array *array;
 584         struct db_record *rec;
 585         DATA_BLOB blob;
 586         TDB_DATA dbuf;
 587         TDB_DATA value;
 588         enum ndr_err_code ndr_err;
 589         NTSTATUS status;
 590         int i;
 591
 592         if (notify == NULL) {
 593                 return NT_STATUS_NOT_IMPLEMENTED;
 594         }
 595
 596         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 597         if (array == NULL) {
 598                 return NT_STATUS_NO_MEMORY;
 599         }
 600
 601         rec = dbwrap_fetch_locked(
 602                 notify->db_onelevel, array,
 603                 make_tdb_data((const uint8_t *)fid, sizeof(*fid)));
 604         if (rec == NULL) {
 605                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 606                            "\n", file_id_string_tos(fid)));
 607                 TALLOC_FREE(array);
 608                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 609         }
 610
 611         value = dbwrap_record_get_value(rec);
 612         blob.data = (uint8_t *)value.dptr;
 613         blob.length = value.dsize;
 614
 615         if (blob.length > 0) {
 616                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 617                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 618                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 619                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 620                                    ndr_errstr(ndr_err)));
 621                         TALLOC_FREE(array);
 622                         return ndr_map_error2ntstatus(ndr_err);
 623                 }
 624                 if (DEBUGLEVEL >= 10) {
 625                         DEBUG(10, ("notify_remove_onelevel:\n"));
 626                         NDR_PRINT_DEBUG(notify_entry_array, array);
 627                 }
 628         }
 629
 630         for (i=0; i<array->num_entries; i++) {
 631                 if ((private_data == array->entries[i].private_data) &&
 632                     procid_equal(&notify->server, &array->entries[i].server)) {
 633                         break;
 634                 }
 635         }
 636
 637         if (i == array->num_entries) {
 638                 TALLOC_FREE(array);
 639                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 640         }
 641
 642         array->entries[i] = array->entries[array->num_entries-1];
 643         array->num_entries -= 1;
 644
 645         if (array->num_entries == 0) {
 646                 dbwrap_record_delete(rec);
 647                 TALLOC_FREE(array);
 648                 return NT_STATUS_OK;
 649         }
 650
 651         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 652                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 653         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 654                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 655                            ndr_errstr(ndr_err)));
 656                 TALLOC_FREE(array);
 657                 return ndr_map_error2ntstatus(ndr_err);
 658         }
 659
 660         if (DEBUGLEVEL >= 10) {
 661                 DEBUG(10, ("notify_add_onelevel:\n"));
 662                 NDR_PRINT_DEBUG(notify_entry_array, array);
 663         }
 664
 665         dbuf.dptr = blob.data;
 666         dbuf.dsize = blob.length;
 667
 668         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 669         TALLOC_FREE(array);
 670         if (!NT_STATUS_IS_OK(status)) {
 671                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 672                            nt_errstr(status)));
 673                 return status;
 674         }
 675         return NT_STATUS_OK;
 676 }
 677
 678 /*
 679   remove a notify watch. Called when the directory handle is closed
 680 */
 681 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 682 {
 683         NTSTATUS status;
 684         struct notify_list *listel;
 685         int i, depth;
 686         struct notify_depth *d;
 687         struct db_record *rec;
 688
 689         /* see if change notify is enabled at all */
 690         if (notify == NULL) {
 691                 return NT_STATUS_NOT_IMPLEMENTED;
 692         }
 693
 694         for (listel=notify->list;listel;listel=listel->next) {
 695                 if (listel->private_data == private_data) {
 696                         DLIST_REMOVE(notify->list, listel);
 697                         break;
 698                 }
 699         }
 700         if (listel == NULL) {
 701                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 702         }
 703
 704         depth = listel->depth;
 705
 706         talloc_free(listel);
 707
 708         status = notify_fetch_locked(notify, &rec);
 709         NT_STATUS_NOT_OK_RETURN(status);
 710
 711         status = notify_load(notify, rec);
 712         if (!NT_STATUS_IS_OK(status)) {
 713                 talloc_free(rec);
 714                 return status;
 715         }
 716
 717         if (depth >= notify->array->num_depths) {
 718                 talloc_free(rec);
 719                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 720         }
 721
 722         /* we only have to search at the depth of this element */
 723         d = &notify->array->depth[depth];
 724
 725         for (i=0;i<d->num_entries;i++) {
 726                 if (private_data == d->entries[i].private_data &&
 727                     procid_equal(&notify->server, &d->entries[i].server)) {
 728                         break;
 729                 }
 730         }
 731         if (i == d->num_entries) {
 732                 talloc_free(rec);
 733                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 734         }
 735
 736         if (i < d->num_entries-1) {
 737                 memmove(&d->entries[i], &d->entries[i+1],
 738                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 739         }
 740         d->num_entries--;
 741
 742         status = notify_save(notify, rec);
 743
 744         talloc_free(rec);
 745
 746         return status;
 747 }
 748
 749 /*
 750   remove all notify watches for a messaging server
 751 */
 752 static NTSTATUS notify_remove_all(struct notify_context *notify,
 753                                   const struct server_id *server)
 754 {
 755         NTSTATUS status;
 756         int i, depth, del_count=0;
 757         struct db_record *rec;
 758
 759         status = notify_fetch_locked(notify, &rec);
 760         NT_STATUS_NOT_OK_RETURN(status);
 761
 762         status = notify_load(notify, rec);
 763         if (!NT_STATUS_IS_OK(status)) {
 764                 talloc_free(rec);
 765                 return status;
 766         }
 767
 768         /* we have to search for all entries across all depths, looking for matches
 769            for the server id */
 770         for (depth=0;depth<notify->array->num_depths;depth++) {
 771                 struct notify_depth *d = &notify->array->depth[depth];
 772                 for (i=0;i<d->num_entries;i++) {
 773                         if (procid_equal(server, &d->entries[i].server)) {
 774                                 if (i < d->num_entries-1) {
 775                                         memmove(&d->entries[i], &d->entries[i+1],
 776                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 777                                 }
 778                                 i--;
 779                                 d->num_entries--;
 780                                 del_count++;
 781                         }
 782                 }
 783         }
 784
 785         if (del_count > 0) {
 786                 status = notify_save(notify, rec);
 787         }
 788
 789         talloc_free(rec);
 790
 791         return status;
 792 }
 793
 794
 795 /*
 796   send a notify message to another messaging server
 797 */
 798 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 799                             const char *path, uint32_t action)
 800 {
 801         struct notify_event ev;
 802         DATA_BLOB data;
 803         NTSTATUS status;
 804         enum ndr_err_code ndr_err;
 805
 806         ev.action = action;
 807         ev.path = path;
 808         ev.private_data = e->private_data;
 809
 810         ndr_err = ndr_push_struct_blob(&data, talloc_tos(), &ev,
 811                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 812         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 813                 return ndr_map_error2ntstatus(ndr_err);
 814         }
 815
 816         status = messaging_send(notify->messaging_ctx, e->server,
 817                                 MSG_PVFS_NOTIFY, &data);
 818         TALLOC_FREE(data.data);
 819         return status;
 820 }
 821
 822 void notify_onelevel(struct notify_context *notify, uint32_t action,
 823                      uint32_t filter, struct file_id fid, const char *name)
 824 {
 825         struct notify_entry_array *array;
 826         TDB_DATA dbuf;
 827         DATA_BLOB blob;
 828         bool have_dead_entries = false;
 829         int i;
 830         NTSTATUS status;
 831
 832         if (notify == NULL) {
 833                 return;
 834         }
 835
 836         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 837         if (array == NULL) {
 838                 return;
 839         }
 840
 841         status = dbwrap_fetch(notify->db_onelevel, array,
 842                               make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 843                               &dbuf);
 844         if (!NT_STATUS_IS_OK(status)) {
 845                 TALLOC_FREE(array);
 846                 return;
 847         }
 848
 849         blob.data = (uint8 *)dbuf.dptr;
 850         blob.length = dbuf.dsize;
 851
 852         if (blob.length > 0) {
 853                 enum ndr_err_code ndr_err;
 854                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 855                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 856                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 857                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 858                                    ndr_errstr(ndr_err)));
 859                         TALLOC_FREE(array);
 860                         return;
 861                 }
 862                 if (DEBUGLEVEL >= 10) {
 863                         DEBUG(10, ("notify_onelevel:\n"));
 864                         NDR_PRINT_DEBUG(notify_entry_array, array);
 865                 }
 866         }
 867
 868         for (i=0; i<array->num_entries; i++) {
 869                 struct notify_entry *e = &array->entries[i];
 870
 871                 if ((e->filter & filter) != 0) {
 872                         status = notify_send(notify, e, name, action);
 873                         if (NT_STATUS_EQUAL(
 874                                     status, NT_STATUS_INVALID_HANDLE)) {
 875                                 /*
 876                                  * Mark the entry as dead. All entries have a
 877                                  * path set. The marker used here is setting
 878                                  * that to NULL.
 879                                  */
 880                                 e->path = NULL;
 881                                 have_dead_entries = true;
 882                         }
 883                 }
 884         }
 885
 886         if (!have_dead_entries) {
 887                 TALLOC_FREE(array);
 888                 return;
 889         }
 890
 891         for (i=0; i<array->num_entries; i++) {
 892                 struct notify_entry *e = &array->entries[i];
 893                 if (e->path != NULL) {
 894                         continue;
 895                 }
 896                 DEBUG(10, ("Deleting notify entries for process %s because "
 897                            "it's gone\n", procid_str_static(&e->server)));
 898                 /*
 899                  * Potential TODO: This might need optimizing,
 900                  * notify_remove_onelevel() does a fetch_locked() operation at
 901                  * every call. But this would only matter if a process with
 902                  * MANY notifies has died without shutting down properly.
 903                  */
 904                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 905         }
 906
 907         TALLOC_FREE(array);
 908         return;
 909 }
 910
 911 /*
 912   trigger a notify message for anyone waiting on a matching event
 913
 914   This function is called a lot, and needs to be very fast. The unusual data structure
 915   and traversal is designed to be fast in the average case, even for large numbers of
 916   notifies
 917 */
 918 void notify_trigger(struct notify_context *notify,
 919                     uint32_t action, uint32_t filter, const char *path)
 920 {
 921         NTSTATUS status;
 922         int depth;
 923         const char *p, *next_p;
 924
 925         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 926                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 927
 928         /* see if change notify is enabled at all */
 929         if (notify == NULL) {
 930                 return;
 931         }
 932
 933  again:
 934         status = notify_load(notify, NULL);
 935         if (!NT_STATUS_IS_OK(status)) {
 936                 return;
 937         }
 938
 939         /* loop along the given path, working with each directory depth separately */
 940         for (depth=0,p=path;
 941              p && depth < notify->array->num_depths;
 942              p=next_p,depth++) {
 943                 int p_len = p - path;
 944                 int min_i, max_i, i;
 945                 struct notify_depth *d = &notify->array->depth[depth];
 946                 uint32_t d_max_mask;
 947                 next_p = strchr(p+1, '/');
 948
 949                 /* see if there are any entries at this depth */
 950                 if (d->num_entries == 0) continue;
 951
 952                 /* try to skip based on the maximum mask. If next_p is
 953                  NULL then we know it will be a 'this directory'
 954                  match, otherwise it must be a subdir match */
 955
 956                 d_max_mask = next_p ? d->max_mask_subdir : d->max_mask;
 957
 958                 if ((filter & d_max_mask) == 0) {
 959                         continue;
 960                 }
 961
 962                 /* we know there is an entry here worth looking
 963                  for. Use a bisection search to find the first entry
 964                  with a matching path */
 965                 min_i = 0;
 966                 max_i = d->num_entries-1;
 967
 968                 while (min_i < max_i) {
 969                         struct notify_entry *e;
 970                         int cmp;
 971                         i = (min_i+max_i)/2;
 972                         e = &d->entries[i];
 973                         cmp = strncmp(path, e->path, p_len);
 974                         if (cmp == 0) {
 975                                 if (p_len == e->path_len) {
 976                                         max_i = i;
 977                                 } else {
 978                                         max_i = i-1;
 979                                 }
 980                         } else if (cmp < 0) {
 981                                 max_i = i-1;
 982                         } else {
 983                                 min_i = i+1;
 984                         }
 985                 }
 986
 987                 if (min_i != max_i) {
 988                         /* none match */
 989                         continue;
 990                 }
 991
 992                 /* we now know that the entries start at min_i */
 993                 for (i=min_i;i<d->num_entries;i++) {
 994                         struct notify_entry *e = &d->entries[i];
 995                         uint32_t e_filter;
 996                         if (p_len != e->path_len ||
 997                             strncmp(path, e->path, p_len) != 0) break;
 998
 999                         e_filter = next_p ? e->subdir_filter : e->filter;
1000
1001                         if ((filter & e_filter) == 0) {
1002                                 continue;
1003                         }
1004
1005                         status = notify_send(notify, e, path + e->path_len + 1,
1006                                              action);
1007
1008                         if (NT_STATUS_EQUAL(
1009                                     status, NT_STATUS_INVALID_HANDLE)) {
1010                                 struct server_id server = e->server;
1011
1012                                 DEBUG(10, ("Deleting notify entries for "
1013                                            "process %s because it's gone\n",
1014                                            procid_str_static(&e->server)));
1015                                 notify_remove_all(notify, &server);
1016                                 goto again;
1017                         }
1018                 }
1019         }
1020 }