source3/smbd/notify_internal.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Andrew Tridgell 2006
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21   this is the change notify database. It implements mechanisms for
  22   storing current change notify waiters in a tdb, and checking if a
  23   given event matches any of the stored notify waiiters.
  24 */
  25
  26 #include "includes.h"
  27 #include "system/filesys.h"
  28 #include "librpc/gen_ndr/ndr_notify.h"
  29 #include "dbwrap.h"
  30 #include "smbd/smbd.h"
  31 #include "messages.h"
  32 #include "lib/util/tdb_wrap.h"
  33 #include "util_tdb.h"
  34
  35 struct notify_context {
  36         struct db_context *db_recursive;
  37         struct db_context *db_onelevel;
  38         struct server_id server;
  39         struct messaging_context *messaging_ctx;
  40         struct notify_list *list;
  41         struct notify_array *array;
  42         int seqnum;
  43         struct sys_notify_context *sys_notify_ctx;
  44         TDB_DATA key;
  45 };
  46
  47
  48 struct notify_list {
  49         struct notify_list *next, *prev;
  50         void *private_data;
  51         void (*callback)(void *, const struct notify_event *);
  52         void *sys_notify_handle;
  53         int depth;
  54 };
  55
  56 #define NOTIFY_KEY "notify array"
  57
  58 #define NOTIFY_ENABLE           "notify:enable"
  59 #define NOTIFY_ENABLE_DEFAULT   True
  60
  61 static NTSTATUS notify_remove_all(struct notify_context *notify,
  62                                   const struct server_id *server);
  63 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
  64                            uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
  65
  66 /*
  67   destroy the notify context
  68 */
  69 static int notify_destructor(struct notify_context *notify)
  70 {
  71         messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
  72
  73         if (notify->list != NULL) {
  74                 notify_remove_all(notify, &notify->server);
  75         }
  76
  77         return 0;
  78 }
  79
  80 /*
  81   Open up the notify.tdb database. You should close it down using
  82   talloc_free(). We need the messaging_ctx to allow for notifications
  83   via internal messages
  84 */
  85 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
  86                                    struct messaging_context *messaging_ctx,
  87                                    struct event_context *ev,
  88                                    connection_struct *conn)
  89 {
  90         struct notify_context *notify;
  91
  92         if (!lp_change_notify(conn->params)) {
  93                 return NULL;
  94         }
  95
  96         notify = talloc(mem_ctx, struct notify_context);
  97         if (notify == NULL) {
  98                 return NULL;
  99         }
 100
 101         notify->db_recursive = db_open(notify, lock_path("notify.tdb"),
 102                                        0, TDB_SEQNUM|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 103                                        O_RDWR|O_CREAT, 0644);
 104         if (notify->db_recursive == NULL) {
 105                 talloc_free(notify);
 106                 return NULL;
 107         }
 108
 109         notify->db_onelevel = db_open(notify, lock_path("notify_onelevel.tdb"),
 110                                       0, TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
 111                                       O_RDWR|O_CREAT, 0644);
 112         if (notify->db_onelevel == NULL) {
 113                 talloc_free(notify);
 114                 return NULL;
 115         }
 116
 117         notify->server = server;
 118         notify->messaging_ctx = messaging_ctx;
 119         notify->list = NULL;
 120         notify->array = NULL;
 121         notify->seqnum = notify->db_recursive->get_seqnum(
 122                 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 = notify->db_recursive->fetch_locked(notify->db_recursive,
 175                                                   notify, notify->key);
 176         if (*rec == NULL) {
 177                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 178         }
 179         return NT_STATUS_OK;
 180 }
 181
 182 /*
 183   load the notify array
 184 */
 185 static NTSTATUS notify_load(struct notify_context *notify, struct db_record *rec)
 186 {
 187         TDB_DATA dbuf;
 188         DATA_BLOB blob;
 189         NTSTATUS status;
 190         int seqnum;
 191
 192         seqnum = notify->db_recursive->get_seqnum(notify->db_recursive);
 193
 194         if (seqnum == notify->seqnum && notify->array != NULL) {
 195                 return NT_STATUS_OK;
 196         }
 197
 198         notify->seqnum = seqnum;
 199
 200         talloc_free(notify->array);
 201         notify->array = TALLOC_ZERO_P(notify, struct notify_array);
 202         NT_STATUS_HAVE_NO_MEMORY(notify->array);
 203
 204         if (!rec) {
 205                 if (notify->db_recursive->fetch(notify->db_recursive, notify,
 206                                                 notify->key, &dbuf) != 0) {
 207                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 208                 }
 209         } else {
 210                 dbuf = rec->value;
 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                                 rec->delete_rec(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 rec->delete_rec(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 = rec->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         enum ndr_err_code ndr_err;
 415         NTSTATUS status;
 416
 417         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 418         if (array == NULL) {
 419                 return;
 420         }
 421
 422         rec = notify->db_onelevel->fetch_locked(
 423                 notify->db_onelevel, talloc_tos(),
 424                 make_tdb_data((uint8_t *)&e->dir_id, sizeof(e->dir_id)));
 425         if (rec == NULL) {
 426                 DEBUG(10, ("notify_add_onelevel: fetch_locked for %s failed"
 427                            "\n", file_id_string_tos(&e->dir_id)));
 428                 TALLOC_FREE(array);
 429                 return;
 430         }
 431
 432         blob.data = (uint8_t *)rec->value.dptr;
 433         blob.length = rec->value.dsize;
 434
 435         if (blob.length > 0) {
 436                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 437                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 438                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 439                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 440                                    ndr_errstr(ndr_err)));
 441                         TALLOC_FREE(array);
 442                         return;
 443                 }
 444                 if (DEBUGLEVEL >= 10) {
 445                         DEBUG(10, ("notify_add_onelevel:\n"));
 446                         NDR_PRINT_DEBUG(notify_entry_array, array);
 447                 }
 448         }
 449
 450         array->entries = talloc_realloc(array, array->entries,
 451                                         struct notify_entry,
 452                                         array->num_entries+1);
 453         if (array->entries == NULL) {
 454                 TALLOC_FREE(array);
 455                 return;
 456         }
 457         array->entries[array->num_entries] = *e;
 458         array->entries[array->num_entries].private_data = private_data;
 459         array->entries[array->num_entries].server = notify->server;
 460         array->num_entries += 1;
 461
 462         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 463                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 464         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 465                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 466                            ndr_errstr(ndr_err)));
 467                 TALLOC_FREE(array);
 468                 return;
 469         }
 470
 471         if (DEBUGLEVEL >= 10) {
 472                 DEBUG(10, ("notify_add_onelevel:\n"));
 473                 NDR_PRINT_DEBUG(notify_entry_array, array);
 474         }
 475
 476         dbuf.dptr = blob.data;
 477         dbuf.dsize = blob.length;
 478
 479         status = rec->store(rec, dbuf, TDB_REPLACE);
 480         TALLOC_FREE(array);
 481         if (!NT_STATUS_IS_OK(status)) {
 482                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 483                            nt_errstr(status)));
 484                 return;
 485         }
 486         e->filter = 0;
 487         return;
 488 }
 489
 490
 491 /*
 492   add a notify watch. This is called when a notify is first setup on a open
 493   directory handle.
 494 */
 495 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
 496                     void (*callback)(void *, const struct notify_event *),
 497                     void *private_data)
 498 {
 499         struct notify_entry e = *e0;
 500         NTSTATUS status;
 501         char *tmp_path = NULL;
 502         struct notify_list *listel;
 503         size_t len;
 504         int depth;
 505         struct db_record *rec;
 506
 507         /* see if change notify is enabled at all */
 508         if (notify == NULL) {
 509                 return NT_STATUS_NOT_IMPLEMENTED;
 510         }
 511
 512         status = notify_fetch_locked(notify, &rec);
 513         NT_STATUS_NOT_OK_RETURN(status);
 514
 515         status = notify_load(notify, rec);
 516         if (!NT_STATUS_IS_OK(status)) {
 517                 talloc_free(rec);
 518                 return status;
 519         }
 520
 521         /* cope with /. on the end of the path */
 522         len = strlen(e.path);
 523         if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
 524                 tmp_path = talloc_strndup(notify, e.path, len-2);
 525                 if (tmp_path == NULL) {
 526                         status = NT_STATUS_NO_MEMORY;
 527                         goto done;
 528                 }
 529                 e.path = tmp_path;
 530         }
 531
 532         depth = count_chars(e.path, '/');
 533
 534         listel = TALLOC_ZERO_P(notify, struct notify_list);
 535         if (listel == NULL) {
 536                 status = NT_STATUS_NO_MEMORY;
 537                 goto done;
 538         }
 539
 540         listel->private_data = private_data;
 541         listel->callback = callback;
 542         listel->depth = depth;
 543         DLIST_ADD(notify->list, listel);
 544
 545         /* ignore failures from sys_notify */
 546         if (notify->sys_notify_ctx != NULL) {
 547                 /*
 548                   this call will modify e.filter and e.subdir_filter
 549                   to remove bits handled by the backend
 550                 */
 551                 status = sys_notify_watch(notify->sys_notify_ctx, &e,
 552                                           sys_notify_callback, listel,
 553                                           &listel->sys_notify_handle);
 554                 if (NT_STATUS_IS_OK(status)) {
 555                         talloc_steal(listel, listel->sys_notify_handle);
 556                 }
 557         }
 558
 559         if (e.filter != 0) {
 560                 notify_add_onelevel(notify, &e, private_data);
 561                 status = NT_STATUS_OK;
 562         }
 563
 564         /* if the system notify handler couldn't handle some of the
 565            filter bits, or couldn't handle a request for recursion
 566            then we need to install it in the array used for the
 567            intra-samba notify handling */
 568         if (e.filter != 0 || e.subdir_filter != 0) {
 569                 status = notify_add_array(notify, rec, &e, private_data, depth);
 570         }
 571
 572 done:
 573         talloc_free(rec);
 574         talloc_free(tmp_path);
 575
 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         enum ndr_err_code ndr_err;
 588         NTSTATUS status;
 589         int i;
 590
 591         if (notify == NULL) {
 592                 return NT_STATUS_NOT_IMPLEMENTED;
 593         }
 594
 595         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 596         if (array == NULL) {
 597                 return NT_STATUS_NO_MEMORY;
 598         }
 599
 600         rec = notify->db_onelevel->fetch_locked(
 601                 notify->db_onelevel, array,
 602                 make_tdb_data((const uint8_t *)fid, sizeof(*fid)));
 603         if (rec == NULL) {
 604                 DEBUG(10, ("notify_remove_onelevel: fetch_locked for %s failed"
 605                            "\n", file_id_string_tos(fid)));
 606                 TALLOC_FREE(array);
 607                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 608         }
 609
 610         blob.data = (uint8_t *)rec->value.dptr;
 611         blob.length = rec->value.dsize;
 612
 613         if (blob.length > 0) {
 614                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 615                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 616                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 617                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 618                                    ndr_errstr(ndr_err)));
 619                         TALLOC_FREE(array);
 620                         return ndr_map_error2ntstatus(ndr_err);
 621                 }
 622                 if (DEBUGLEVEL >= 10) {
 623                         DEBUG(10, ("notify_remove_onelevel:\n"));
 624                         NDR_PRINT_DEBUG(notify_entry_array, array);
 625                 }
 626         }
 627
 628         for (i=0; i<array->num_entries; i++) {
 629                 if ((private_data == array->entries[i].private_data) &&
 630                     cluster_id_equal(&notify->server,
 631                                      &array->entries[i].server)) {
 632                         break;
 633                 }
 634         }
 635
 636         if (i == array->num_entries) {
 637                 TALLOC_FREE(array);
 638                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 639         }
 640
 641         array->entries[i] = array->entries[array->num_entries-1];
 642         array->num_entries -= 1;
 643
 644         if (array->num_entries == 0) {
 645                 rec->delete_rec(rec);
 646                 TALLOC_FREE(array);
 647                 return NT_STATUS_OK;
 648         }
 649
 650         ndr_err = ndr_push_struct_blob(&blob, rec, array,
 651                 (ndr_push_flags_fn_t)ndr_push_notify_entry_array);
 652         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 653                 DEBUG(10, ("ndr_push_notify_entry_array failed: %s\n",
 654                            ndr_errstr(ndr_err)));
 655                 TALLOC_FREE(array);
 656                 return ndr_map_error2ntstatus(ndr_err);
 657         }
 658
 659         if (DEBUGLEVEL >= 10) {
 660                 DEBUG(10, ("notify_add_onelevel:\n"));
 661                 NDR_PRINT_DEBUG(notify_entry_array, array);
 662         }
 663
 664         dbuf.dptr = blob.data;
 665         dbuf.dsize = blob.length;
 666
 667         status = rec->store(rec, dbuf, TDB_REPLACE);
 668         TALLOC_FREE(array);
 669         if (!NT_STATUS_IS_OK(status)) {
 670                 DEBUG(10, ("notify_add_onelevel: store failed: %s\n",
 671                            nt_errstr(status)));
 672                 return status;
 673         }
 674         return NT_STATUS_OK;
 675 }
 676
 677 /*
 678   remove a notify watch. Called when the directory handle is closed
 679 */
 680 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
 681 {
 682         NTSTATUS status;
 683         struct notify_list *listel;
 684         int i, depth;
 685         struct notify_depth *d;
 686         struct db_record *rec;
 687
 688         /* see if change notify is enabled at all */
 689         if (notify == NULL) {
 690                 return NT_STATUS_NOT_IMPLEMENTED;
 691         }
 692
 693         for (listel=notify->list;listel;listel=listel->next) {
 694                 if (listel->private_data == private_data) {
 695                         DLIST_REMOVE(notify->list, listel);
 696                         break;
 697                 }
 698         }
 699         if (listel == NULL) {
 700                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 701         }
 702
 703         depth = listel->depth;
 704
 705         talloc_free(listel);
 706
 707         status = notify_fetch_locked(notify, &rec);
 708         NT_STATUS_NOT_OK_RETURN(status);
 709
 710         status = notify_load(notify, rec);
 711         if (!NT_STATUS_IS_OK(status)) {
 712                 talloc_free(rec);
 713                 return status;
 714         }
 715
 716         if (depth >= notify->array->num_depths) {
 717                 talloc_free(rec);
 718                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 719         }
 720
 721         /* we only have to search at the depth of this element */
 722         d = &notify->array->depth[depth];
 723
 724         for (i=0;i<d->num_entries;i++) {
 725                 if (private_data == d->entries[i].private_data &&
 726                     cluster_id_equal(&notify->server, &d->entries[i].server)) {
 727                         break;
 728                 }
 729         }
 730         if (i == d->num_entries) {
 731                 talloc_free(rec);
 732                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 733         }
 734
 735         if (i < d->num_entries-1) {
 736                 memmove(&d->entries[i], &d->entries[i+1],
 737                         sizeof(d->entries[i])*(d->num_entries-(i+1)));
 738         }
 739         d->num_entries--;
 740
 741         status = notify_save(notify, rec);
 742
 743         talloc_free(rec);
 744
 745         return status;
 746 }
 747
 748 /*
 749   remove all notify watches for a messaging server
 750 */
 751 static NTSTATUS notify_remove_all(struct notify_context *notify,
 752                                   const struct server_id *server)
 753 {
 754         NTSTATUS status;
 755         int i, depth, del_count=0;
 756         struct db_record *rec;
 757
 758         status = notify_fetch_locked(notify, &rec);
 759         NT_STATUS_NOT_OK_RETURN(status);
 760
 761         status = notify_load(notify, rec);
 762         if (!NT_STATUS_IS_OK(status)) {
 763                 talloc_free(rec);
 764                 return status;
 765         }
 766
 767         /* we have to search for all entries across all depths, looking for matches
 768            for the server id */
 769         for (depth=0;depth<notify->array->num_depths;depth++) {
 770                 struct notify_depth *d = &notify->array->depth[depth];
 771                 for (i=0;i<d->num_entries;i++) {
 772                         if (cluster_id_equal(server, &d->entries[i].server)) {
 773                                 if (i < d->num_entries-1) {
 774                                         memmove(&d->entries[i], &d->entries[i+1],
 775                                                 sizeof(d->entries[i])*(d->num_entries-(i+1)));
 776                                 }
 777                                 i--;
 778                                 d->num_entries--;
 779                                 del_count++;
 780                         }
 781                 }
 782         }
 783
 784         if (del_count > 0) {
 785                 status = notify_save(notify, rec);
 786         }
 787
 788         talloc_free(rec);
 789
 790         return status;
 791 }
 792
 793
 794 /*
 795   send a notify message to another messaging server
 796 */
 797 static NTSTATUS notify_send(struct notify_context *notify, struct notify_entry *e,
 798                             const char *path, uint32_t action)
 799 {
 800         struct notify_event ev;
 801         DATA_BLOB data;
 802         NTSTATUS status;
 803         enum ndr_err_code ndr_err;
 804         TALLOC_CTX *tmp_ctx;
 805
 806         ev.action = action;
 807         ev.path = path;
 808         ev.private_data = e->private_data;
 809
 810         tmp_ctx = talloc_new(notify);
 811
 812         ndr_err = ndr_push_struct_blob(&data, tmp_ctx, &ev,
 813                                        (ndr_push_flags_fn_t)ndr_push_notify_event);
 814         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 815                 talloc_free(tmp_ctx);
 816                 return ndr_map_error2ntstatus(ndr_err);
 817         }
 818
 819         status = messaging_send(notify->messaging_ctx, e->server,
 820                                 MSG_PVFS_NOTIFY, &data);
 821         talloc_free(tmp_ctx);
 822         return status;
 823 }
 824
 825 void notify_onelevel(struct notify_context *notify, uint32_t action,
 826                      uint32_t filter, struct file_id fid, const char *name)
 827 {
 828         struct notify_entry_array *array;
 829         TDB_DATA dbuf;
 830         DATA_BLOB blob;
 831         bool have_dead_entries = false;
 832         int i;
 833
 834         if (notify == NULL) {
 835                 return;
 836         }
 837
 838         array = talloc_zero(talloc_tos(), struct notify_entry_array);
 839         if (array == NULL) {
 840                 return;
 841         }
 842
 843         if (notify->db_onelevel->fetch(
 844                     notify->db_onelevel, array,
 845                     make_tdb_data((uint8_t *)&fid, sizeof(fid)),
 846                     &dbuf) == -1) {
 847                 TALLOC_FREE(array);
 848                 return;
 849         }
 850
 851         blob.data = (uint8 *)dbuf.dptr;
 852         blob.length = dbuf.dsize;
 853
 854         if (blob.length > 0) {
 855                 enum ndr_err_code ndr_err;
 856                 ndr_err = ndr_pull_struct_blob(&blob, array, array,
 857                         (ndr_pull_flags_fn_t)ndr_pull_notify_entry_array);
 858                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 859                         DEBUG(10, ("ndr_pull_notify_entry_array failed: %s\n",
 860                                    ndr_errstr(ndr_err)));
 861                         TALLOC_FREE(array);
 862                         return;
 863                 }
 864                 if (DEBUGLEVEL >= 10) {
 865                         DEBUG(10, ("notify_onelevel:\n"));
 866                         NDR_PRINT_DEBUG(notify_entry_array, array);
 867                 }
 868         }
 869
 870         for (i=0; i<array->num_entries; i++) {
 871                 struct notify_entry *e = &array->entries[i];
 872
 873                 if ((e->filter & filter) != 0) {
 874                         NTSTATUS status;
 875
 876                         status = notify_send(notify, e, name, action);
 877                         if (NT_STATUS_EQUAL(
 878                                     status, NT_STATUS_INVALID_HANDLE)) {
 879                                 /*
 880                                  * Mark the entry as dead. All entries have a
 881                                  * path set. The marker used here is setting
 882                                  * that to NULL.
 883                                  */
 884                                 e->path = NULL;
 885                                 have_dead_entries = true;
 886                         }
 887                 }
 888         }
 889
 890         if (!have_dead_entries) {
 891                 TALLOC_FREE(array);
 892                 return;
 893         }
 894
 895         for (i=0; i<array->num_entries; i++) {
 896                 struct notify_entry *e = &array->entries[i];
 897                 if (e->path != NULL) {
 898                         continue;
 899                 }
 900                 DEBUG(10, ("Deleting notify entries for process %s because "
 901                            "it's gone\n", procid_str_static(&e->server)));
 902                 /*
 903                  * Potential TODO: This might need optimizing,
 904                  * notify_remove_onelevel() does a fetch_locked() operation at
 905                  * every call. But this would only matter if a process with
 906                  * MANY notifies has died without shutting down properly.
 907                  */
 908                 notify_remove_onelevel(notify, &e->dir_id, e->private_data);
 909         }
 910
 911         TALLOC_FREE(array);
 912         return;
 913 }
 914
 915 /*
 916   trigger a notify message for anyone waiting on a matching event
 917
 918   This function is called a lot, and needs to be very fast. The unusual data structure
 919   and traversal is designed to be fast in the average case, even for large numbers of
 920   notifies
 921 */
 922 void notify_trigger(struct notify_context *notify,
 923                     uint32_t action, uint32_t filter, const char *path)
 924 {
 925         NTSTATUS status;
 926         int depth;
 927         const char *p, *next_p;
 928
 929         DEBUG(10, ("notify_trigger called action=0x%x, filter=0x%x, "
 930                    "path=%s\n", (unsigned)action, (unsigned)filter, path));
 931
 932         /* see if change notify is enabled at all */
 933         if (notify == NULL) {
 934                 return;
 935         }
 936
 937  again:
 938         status = notify_load(notify, NULL);
 939         if (!NT_STATUS_IS_OK(status)) {
 940                 return;
 941         }
 942
 943         /* loop along the given path, working with each directory depth separately */
 944         for (depth=0,p=path;
 945              p && depth < notify->array->num_depths;
 946              p=next_p,depth++) {
 947                 int p_len = p - path;
 948                 int min_i, max_i, i;
 949                 struct notify_depth *d = &notify->array->depth[depth];
 950                 next_p = strchr(p+1, '/');
 951
 952                 /* see if there are any entries at this depth */
 953                 if (d->num_entries == 0) continue;
 954
 955                 /* try to skip based on the maximum mask. If next_p is
 956                  NULL then we know it will be a 'this directory'
 957                  match, otherwise it must be a subdir match */
 958                 if (next_p != NULL) {
 959                         if (0 == (filter & d->max_mask_subdir)) {
 960                                 continue;
 961                         }
 962                 } else {
 963                         if (0 == (filter & d->max_mask)) {
 964                                 continue;
 965                         }
 966                 }
 967
 968                 /* we know there is an entry here worth looking
 969                  for. Use a bisection search to find the first entry
 970                  with a matching path */
 971                 min_i = 0;
 972                 max_i = d->num_entries-1;
 973
 974                 while (min_i < max_i) {
 975                         struct notify_entry *e;
 976                         int cmp;
 977                         i = (min_i+max_i)/2;
 978                         e = &d->entries[i];
 979                         cmp = strncmp(path, e->path, p_len);
 980                         if (cmp == 0) {
 981                                 if (p_len == e->path_len) {
 982                                         max_i = i;
 983                                 } else {
 984                                         max_i = i-1;
 985                                 }
 986                         } else if (cmp < 0) {
 987                                 max_i = i-1;
 988                         } else {
 989                                 min_i = i+1;
 990                         }
 991                 }
 992
 993                 if (min_i != max_i) {
 994                         /* none match */
 995                         continue;
 996                 }
 997
 998                 /* we now know that the entries start at min_i */
 999                 for (i=min_i;i<d->num_entries;i++) {
1000                         struct notify_entry *e = &d->entries[i];
1001                         if (p_len != e->path_len ||
1002                             strncmp(path, e->path, p_len) != 0) break;
1003                         if (next_p != NULL) {
1004                                 if (0 == (filter & e->subdir_filter)) {
1005                                         continue;
1006                                 }
1007                         } else {
1008                                 if (0 == (filter & e->filter)) {
1009                                         continue;
1010                                 }
1011                         }
1012                         status = notify_send(notify, e, path + e->path_len + 1,
1013                                              action);
1014
1015                         if (NT_STATUS_EQUAL(
1016                                     status, NT_STATUS_INVALID_HANDLE)) {
1017                                 struct server_id server = e->server;
1018
1019                                 DEBUG(10, ("Deleting notify entries for "
1020                                            "process %s because it's gone\n",
1021                                            procid_str_static(&e->server)));
1022                                 notify_remove_all(notify, &server);
1023                                 goto again;
1024                         }
1025                 }
1026         }
1027 }