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