source3/smbd/notify.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    change notify handling
   4    Copyright (C) Andrew Tridgell 2000
   5    Copyright (C) Jeremy Allison 1994-1998
   6    Copyright (C) Volker Lendecke 2007
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "../librpc/gen_ndr/ndr_notify.h"
  26 #include "librpc/gen_ndr/ndr_file_id.h"
  27 #include "libcli/security/privileges.h"
  28 #include "libcli/security/security.h"
  29
  30 struct notify_change_event {
  31         struct timespec when;
  32         uint32_t action;
  33         const char *name;
  34 };
  35
  36 struct notify_change_buf {
  37         /*
  38          * Filters for reinitializing after notifyd has been restarted
  39          */
  40         uint32_t filter;
  41         uint32_t subdir_filter;
  42
  43         /*
  44          * If no requests are pending, changes are queued here. Simple array,
  45          * we only append.
  46          */
  47
  48         uint32_t max_buffer_size;
  49
  50         /*
  51          * num_changes == -1 means that we have got a catch-all change, when
  52          * asked we just return NT_STATUS_OK without specific changes.
  53          */
  54         int num_changes;
  55         struct notify_change_event *changes;
  56
  57         /*
  58          * If no changes are around requests are queued here. Using a linked
  59          * list, because we have to append at the end and delete from the top.
  60          */
  61         struct notify_change_request *requests;
  62 };
  63
  64 struct notify_change_request {
  65         struct notify_change_request *prev, *next;
  66         struct files_struct *fsp;       /* backpointer for cancel by mid */
  67         struct smb_request *req;
  68         uint32_t filter;
  69         uint32_t max_param;
  70         void (*reply_fn)(struct smb_request *req,
  71                          NTSTATUS error_code,
  72                          uint8_t *buf, size_t len);
  73         struct notify_mid_map *mid_map;
  74         void *backend_data;
  75 };
  76
  77 static void notify_fsp(files_struct *fsp, struct timespec when,
  78                        uint32_t action, const char *name);
  79
  80 bool change_notify_fsp_has_changes(struct files_struct *fsp)
  81 {
  82         if (fsp == NULL) {
  83                 return false;
  84         }
  85
  86         if (fsp->notify == NULL) {
  87                 return false;
  88         }
  89
  90         if (fsp->notify->num_changes == 0) {
  91                 return false;
  92         }
  93
  94         return true;
  95 }
  96
  97 /*
  98  * For NTCancel, we need to find the notify_change_request indexed by
  99  * mid. Separate list here.
 100  */
 101
 102 struct notify_mid_map {
 103         struct notify_mid_map *prev, *next;
 104         struct notify_change_request *req;
 105         uint64_t mid;
 106 };
 107
 108 static bool notify_change_record_identical(struct notify_change_event *c1,
 109                                            struct notify_change_event *c2)
 110 {
 111         /* Note this is deliberately case sensitive. */
 112         if (c1->action == c2->action &&
 113                         strcmp(c1->name, c2->name) == 0) {
 114                 return True;
 115         }
 116         return False;
 117 }
 118
 119 static int compare_notify_change_events(const void *p1, const void *p2)
 120 {
 121         const struct notify_change_event *e1 = p1;
 122         const struct notify_change_event *e2 = p2;
 123
 124         return timespec_compare(&e1->when, &e2->when);
 125 }
 126
 127 static bool notify_marshall_changes(int num_changes,
 128                                 uint32_t max_offset,
 129                                 struct notify_change_event *changes,
 130                                 DATA_BLOB *final_blob)
 131 {
 132         int i;
 133
 134         if (num_changes == -1) {
 135                 return false;
 136         }
 137
 138         /*
 139          * Sort the notifies by timestamp when the event happened to avoid
 140          * coalescing and thus dropping events.
 141          */
 142
 143         qsort(changes, num_changes,
 144               sizeof(*changes), compare_notify_change_events);
 145
 146         for (i=0; i<num_changes; i++) {
 147                 enum ndr_err_code ndr_err;
 148                 struct notify_change_event *c;
 149                 struct FILE_NOTIFY_INFORMATION m;
 150                 DATA_BLOB blob;
 151                 uint16_t pad = 0;
 152
 153                 /* Coalesce any identical records. */
 154                 while (i+1 < num_changes &&
 155                         notify_change_record_identical(&changes[i],
 156                                                 &changes[i+1])) {
 157                         i++;
 158                 }
 159
 160                 c = &changes[i];
 161
 162                 m.FileName1 = c->name;
 163                 m.FileNameLength = strlen_m(c->name)*2;
 164                 m.Action = c->action;
 165
 166                 m._pad = data_blob_null;
 167
 168                 /*
 169                  * Offset to next entry, only if there is one
 170                  */
 171
 172                 if (i == (num_changes-1)) {
 173                         m.NextEntryOffset = 0;
 174                 } else {
 175                         if ((m.FileNameLength % 4) == 2) {
 176                                 m._pad = data_blob_const(&pad, 2);
 177                         }
 178                         m.NextEntryOffset =
 179                                 ndr_size_FILE_NOTIFY_INFORMATION(&m, 0);
 180                 }
 181
 182                 ndr_err = ndr_push_struct_blob(&blob, talloc_tos(), &m,
 183                         (ndr_push_flags_fn_t)ndr_push_FILE_NOTIFY_INFORMATION);
 184                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 185                         return false;
 186                 }
 187
 188                 if (DEBUGLEVEL >= 10) {
 189                         NDR_PRINT_DEBUG(FILE_NOTIFY_INFORMATION, &m);
 190                 }
 191
 192                 if (!data_blob_append(talloc_tos(), final_blob,
 193                                       blob.data, blob.length)) {
 194                         data_blob_free(&blob);
 195                         return false;
 196                 }
 197
 198                 data_blob_free(&blob);
 199
 200                 if (final_blob->length > max_offset) {
 201                         /* Too much data for client. */
 202                         DEBUG(10, ("Client only wanted %d bytes, trying to "
 203                                    "marshall %d bytes\n", (int)max_offset,
 204                                    (int)final_blob->length));
 205                         return False;
 206                 }
 207         }
 208
 209         return True;
 210 }
 211
 212 /****************************************************************************
 213  Setup the common parts of the return packet and send it.
 214 *****************************************************************************/
 215
 216 void change_notify_reply(struct smb_request *req,
 217                          NTSTATUS error_code,
 218                          uint32_t max_param,
 219                          struct notify_change_buf *notify_buf,
 220                          void (*reply_fn)(struct smb_request *req,
 221                                           NTSTATUS error_code,
 222                                           uint8_t *buf, size_t len))
 223 {
 224         DATA_BLOB blob = data_blob_null;
 225
 226         if (!NT_STATUS_IS_OK(error_code)) {
 227                 reply_fn(req, error_code, NULL, 0);
 228                 return;
 229         }
 230
 231         if (notify_buf == NULL) {
 232                 reply_fn(req, NT_STATUS_OK, NULL, 0);
 233                 return;
 234         }
 235
 236         max_param = MIN(max_param, notify_buf->max_buffer_size);
 237
 238         if (!notify_marshall_changes(notify_buf->num_changes, max_param,
 239                                         notify_buf->changes, &blob)) {
 240                 /*
 241                  * We exceed what the client is willing to accept. Send
 242                  * nothing.
 243                  */
 244                 data_blob_free(&blob);
 245         }
 246
 247         reply_fn(req, NT_STATUS_OK, blob.data, blob.length);
 248
 249         data_blob_free(&blob);
 250
 251         TALLOC_FREE(notify_buf->changes);
 252         notify_buf->num_changes = 0;
 253 }
 254
 255 struct notify_fsp_state {
 256         struct files_struct *notified_fsp;
 257         struct timespec when;
 258         const struct notify_event *e;
 259 };
 260
 261 static struct files_struct *notify_fsp_cb(struct files_struct *fsp,
 262                                           void *private_data)
 263 {
 264         struct notify_fsp_state *state = private_data;
 265
 266         if (fsp == state->notified_fsp) {
 267                 DBG_DEBUG("notify_callback called for %s\n", fsp_str_dbg(fsp));
 268                 notify_fsp(fsp, state->when, state->e->action, state->e->path);
 269                 return fsp;
 270         }
 271
 272         return NULL;
 273 }
 274
 275 void notify_callback(struct smbd_server_connection *sconn,
 276                      void *private_data, struct timespec when,
 277                      const struct notify_event *e)
 278 {
 279         struct notify_fsp_state state = {
 280                 .notified_fsp = private_data, .when = when, .e = e
 281         };
 282         files_forall(sconn, notify_fsp_cb, &state);
 283 }
 284
 285 NTSTATUS change_notify_create(struct files_struct *fsp,
 286                               uint32_t max_buffer_size,
 287                               uint32_t filter,
 288                               bool recursive)
 289 {
 290         size_t len = fsp_fullbasepath(fsp, NULL, 0);
 291         char fullpath[len+1];
 292         NTSTATUS status = NT_STATUS_NOT_IMPLEMENTED;
 293
 294         /*
 295          * Setting a changenotify needs READ/LIST access
 296          * on the directory handle.
 297          */
 298         status = check_any_access_fsp(fsp, SEC_DIR_LIST);
 299         if (!NT_STATUS_IS_OK(status)) {
 300                 return status;
 301         }
 302
 303         if (fsp->notify != NULL) {
 304                 DEBUG(1, ("change_notify_create: fsp->notify != NULL, "
 305                           "fname = %s\n", fsp->fsp_name->base_name));
 306                 return NT_STATUS_INVALID_PARAMETER;
 307         }
 308
 309         if (!(fsp->notify = talloc_zero(NULL, struct notify_change_buf))) {
 310                 DEBUG(0, ("talloc failed\n"));
 311                 return NT_STATUS_NO_MEMORY;
 312         }
 313         fsp->notify->filter = filter;
 314         fsp->notify->subdir_filter = recursive ? filter : 0;
 315         fsp->notify->max_buffer_size = max_buffer_size;
 316
 317         fsp_fullbasepath(fsp, fullpath, sizeof(fullpath));
 318
 319         if ((fsp->notify->filter != 0) ||
 320             (fsp->notify->subdir_filter != 0)) {
 321                 status = notify_add(fsp->conn->sconn->notify_ctx,
 322                                     fullpath, fsp->notify->filter,
 323                                     fsp->notify->subdir_filter, fsp);
 324         }
 325
 326         return status;
 327 }
 328
 329 NTSTATUS change_notify_add_request(struct smb_request *req,
 330                                 uint32_t max_param,
 331                                 uint32_t filter, bool recursive,
 332                                 struct files_struct *fsp,
 333                                 void (*reply_fn)(struct smb_request *req,
 334                                         NTSTATUS error_code,
 335                                         uint8_t *buf, size_t len))
 336 {
 337         struct notify_change_request *request = NULL;
 338         struct notify_mid_map *map = NULL;
 339         struct smbd_server_connection *sconn = req->sconn;
 340
 341         DEBUG(10, ("change_notify_add_request: Adding request for %s: "
 342                    "max_param = %d\n", fsp_str_dbg(fsp), (int)max_param));
 343
 344         if (!(request = talloc(NULL, struct notify_change_request))
 345             || !(map = talloc(request, struct notify_mid_map))) {
 346                 TALLOC_FREE(request);
 347                 return NT_STATUS_NO_MEMORY;
 348         }
 349
 350         request->mid_map = map;
 351         map->req = request;
 352
 353         request->req = talloc_move(request, &req);
 354         request->max_param = max_param;
 355         request->filter = filter;
 356         request->fsp = fsp;
 357         request->reply_fn = reply_fn;
 358         request->backend_data = NULL;
 359
 360         DLIST_ADD_END(fsp->notify->requests, request);
 361
 362         map->mid = request->req->mid;
 363         DLIST_ADD(sconn->notify_mid_maps, map);
 364
 365         return NT_STATUS_OK;
 366 }
 367
 368 static void change_notify_remove_request(struct smbd_server_connection *sconn,
 369                                          struct notify_change_request *remove_req)
 370 {
 371         files_struct *fsp;
 372         struct notify_change_request *req;
 373
 374         /*
 375          * Paranoia checks, the fsp referenced must must have the request in
 376          * its list of pending requests
 377          */
 378
 379         fsp = remove_req->fsp;
 380         SMB_ASSERT(fsp->notify != NULL);
 381
 382         for (req = fsp->notify->requests; req; req = req->next) {
 383                 if (req == remove_req) {
 384                         break;
 385                 }
 386         }
 387
 388         if (req == NULL) {
 389                 smb_panic("notify_req not found in fsp's requests");
 390         }
 391
 392         DLIST_REMOVE(fsp->notify->requests, req);
 393         DLIST_REMOVE(sconn->notify_mid_maps, req->mid_map);
 394         TALLOC_FREE(req);
 395 }
 396
 397 static void smbd_notify_cancel_by_map(struct notify_mid_map *map)
 398 {
 399         struct smb_request *smbreq = map->req->req;
 400         struct smbd_server_connection *sconn = smbreq->sconn;
 401         struct smbd_smb2_request *smb2req = smbreq->smb2req;
 402         NTSTATUS notify_status = NT_STATUS_CANCELLED;
 403
 404         if (smb2req != NULL) {
 405                 NTSTATUS sstatus;
 406
 407                 if (smb2req->session == NULL) {
 408                         sstatus = NT_STATUS_USER_SESSION_DELETED;
 409                 } else {
 410                         sstatus = smb2req->session->status;
 411                 }
 412
 413                 if (NT_STATUS_EQUAL(sstatus, NT_STATUS_NETWORK_SESSION_EXPIRED)) {
 414                         sstatus = NT_STATUS_OK;
 415                 }
 416
 417                 if (!NT_STATUS_IS_OK(sstatus)) {
 418                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 419                 } else if (smb2req->tcon == NULL) {
 420                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 421                 } else if (!NT_STATUS_IS_OK(smb2req->tcon->status)) {
 422                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 423                 }
 424         }
 425
 426         change_notify_reply(smbreq, notify_status,
 427                             0, NULL, map->req->reply_fn);
 428         change_notify_remove_request(sconn, map->req);
 429 }
 430
 431 /****************************************************************************
 432  Delete entries by mid from the change notify pending queue. Always send reply.
 433 *****************************************************************************/
 434
 435 bool remove_pending_change_notify_requests_by_mid(
 436         struct smbd_server_connection *sconn, uint64_t mid)
 437 {
 438         struct notify_mid_map *map;
 439
 440         for (map = sconn->notify_mid_maps; map; map = map->next) {
 441                 if (map->mid == mid) {
 442                         break;
 443                 }
 444         }
 445
 446         if (map == NULL) {
 447                 return false;
 448         }
 449
 450         smbd_notify_cancel_by_map(map);
 451         return true;
 452 }
 453
 454 void smbd_notify_cancel_by_smbreq(const struct smb_request *smbreq)
 455 {
 456         struct smbd_server_connection *sconn = smbreq->sconn;
 457         struct notify_mid_map *map;
 458
 459         for (map = sconn->notify_mid_maps; map; map = map->next) {
 460                 if (map->req->req == smbreq) {
 461                         break;
 462                 }
 463         }
 464
 465         if (map == NULL) {
 466                 return;
 467         }
 468
 469         smbd_notify_cancel_by_map(map);
 470 }
 471
 472 static struct files_struct *smbd_notify_cancel_deleted_fn(
 473         struct files_struct *fsp, void *private_data)
 474 {
 475         struct file_id *fid = talloc_get_type_abort(
 476                 private_data, struct file_id);
 477
 478         if (file_id_equal(&fsp->file_id, fid)) {
 479                 remove_pending_change_notify_requests_by_fid(
 480                         fsp, NT_STATUS_DELETE_PENDING);
 481         }
 482         return NULL;
 483 }
 484
 485 void smbd_notify_cancel_deleted(struct messaging_context *msg,
 486                                 void *private_data, uint32_t msg_type,
 487                                 struct server_id server_id, DATA_BLOB *data)
 488 {
 489         struct smbd_server_connection *sconn = talloc_get_type_abort(
 490                 private_data, struct smbd_server_connection);
 491         struct file_id *fid;
 492         enum ndr_err_code ndr_err;
 493
 494         fid = talloc(talloc_tos(), struct file_id);
 495         if (fid == NULL) {
 496                 DEBUG(1, ("talloc failed\n"));
 497                 return;
 498         }
 499
 500         ndr_err = ndr_pull_struct_blob_all(
 501                 data, fid, fid, (ndr_pull_flags_fn_t)ndr_pull_file_id);
 502         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 503                 DEBUG(10, ("%s: ndr_pull_file_id failed: %s\n", __func__,
 504                            ndr_errstr(ndr_err)));
 505                 goto done;
 506         }
 507
 508         files_forall(sconn, smbd_notify_cancel_deleted_fn, fid);
 509
 510 done:
 511         TALLOC_FREE(fid);
 512 }
 513
 514 static struct files_struct *smbd_notifyd_reregister(struct files_struct *fsp,
 515                                                     void *private_data)
 516 {
 517         DBG_DEBUG("reregister %s\n", fsp->fsp_name->base_name);
 518
 519         if ((fsp->conn->sconn->notify_ctx != NULL) &&
 520             (fsp->notify != NULL) &&
 521             ((fsp->notify->filter != 0) ||
 522              (fsp->notify->subdir_filter != 0))) {
 523                 size_t len = fsp_fullbasepath(fsp, NULL, 0);
 524                 char fullpath[len+1];
 525
 526                 NTSTATUS status;
 527
 528                 fsp_fullbasepath(fsp, fullpath, sizeof(fullpath));
 529
 530                 status = notify_add(fsp->conn->sconn->notify_ctx,
 531                                     fullpath, fsp->notify->filter,
 532                                     fsp->notify->subdir_filter, fsp);
 533                 if (!NT_STATUS_IS_OK(status)) {
 534                         DBG_DEBUG("notify_add failed: %s\n",
 535                                   nt_errstr(status));
 536                 }
 537         }
 538         return NULL;
 539 }
 540
 541 void smbd_notifyd_restarted(struct messaging_context *msg,
 542                             void *private_data, uint32_t msg_type,
 543                             struct server_id server_id, DATA_BLOB *data)
 544 {
 545         struct smbd_server_connection *sconn = talloc_get_type_abort(
 546                 private_data, struct smbd_server_connection);
 547
 548         TALLOC_FREE(sconn->notify_ctx);
 549
 550         sconn->notify_ctx = notify_init(sconn, sconn->msg_ctx,
 551                                         sconn, notify_callback);
 552         if (sconn->notify_ctx == NULL) {
 553                 DBG_DEBUG("notify_init failed\n");
 554                 return;
 555         }
 556
 557         files_forall(sconn, smbd_notifyd_reregister, sconn->notify_ctx);
 558 }
 559
 560 /****************************************************************************
 561  Delete entries by fnum from the change notify pending queue.
 562 *****************************************************************************/
 563
 564 void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
 565                                                   NTSTATUS status)
 566 {
 567         if (fsp->notify == NULL) {
 568                 return;
 569         }
 570
 571         while (fsp->notify->requests != NULL) {
 572                 change_notify_reply(fsp->notify->requests->req,
 573                                     status, 0, NULL,
 574                                     fsp->notify->requests->reply_fn);
 575                 change_notify_remove_request(fsp->conn->sconn,
 576                                              fsp->notify->requests);
 577         }
 578 }
 579
 580 void notify_fname(struct connection_struct *conn,
 581                   uint32_t action,
 582                   uint32_t filter,
 583                   const struct smb_filename *smb_fname,
 584                   const struct smb2_lease *lease)
 585 {
 586         struct notify_context *notify_ctx = conn->sconn->notify_ctx;
 587         const char *path = smb_fname->base_name;
 588
 589         if (action & NOTIFY_ACTION_DIRLEASE_BREAK) {
 590                 contend_dirleases(conn, smb_fname, lease);
 591         }
 592         action &= ~NOTIFY_ACTION_DIRLEASE_BREAK;
 593         if (action == 0) {
 594                 return;
 595         }
 596
 597         if (path[0] == '.' && path[1] == '/') {
 598                 path += 2;
 599         }
 600
 601         notify_trigger(notify_ctx, action, filter, conn->connectpath, path);
 602 }
 603
 604 static bool user_can_stat_name_under_fsp(files_struct *fsp, const char *name)
 605 {
 606         uint32_t rights;
 607         struct smb_filename *fname = NULL;
 608         char *filepath = NULL;
 609         NTSTATUS status;
 610         char *p = NULL;
 611
 612         /*
 613          * Assume we get filepath (relative to the share)
 614          * like this:
 615          *
 616          *  'dir1/dir2/dir3/file'
 617          *
 618          * We start with LIST and TRAVERSE on the
 619          * direct parent ('dir1/dir2/dir3')
 620          *
 621          * Then we switch to just TRAVERSE for
 622          * the rest: 'dir1/dir2', 'dir1', '.'
 623          *
 624          * For a file in the share root, we'll have
 625          *  'file'
 626          * and would just check '.' with LIST and TRAVERSE.
 627          *
 628          * It's important to always check '.' as the last step,
 629          * which means we check the permissions of the share root
 630          * directory.
 631          */
 632
 633         if (ISDOT(fsp->fsp_name->base_name)) {
 634                 filepath = talloc_strdup(talloc_tos(), name);
 635         } else {
 636                 filepath = talloc_asprintf(talloc_tos(),
 637                         "%s/%s",
 638                         fsp->fsp_name->base_name,
 639                         name);
 640         }
 641         if (filepath == NULL) {
 642                 DBG_ERR("Memory allocation failed\n");
 643                 return false;
 644         }
 645
 646         rights = SEC_DIR_LIST|SEC_DIR_TRAVERSE;
 647         p = strrchr_m(filepath, '/');
 648         /*
 649          * Check each path component, excluding the share root.
 650          *
 651          * We could check all components including root using
 652          * a do { .. } while() loop, but IMHO the logic is clearer
 653          * having the share root check separately afterwards.
 654          */
 655         while (p != NULL) {
 656                 *p = '\0';
 657                 status = synthetic_pathref(talloc_tos(),
 658                                            fsp->conn->cwd_fsp,
 659                                            filepath,
 660                                            NULL,
 661                                            NULL,
 662                                            0,
 663                                            0,
 664                                            &fname);
 665                 if (!NT_STATUS_IS_OK(status)) {
 666                         int dbg_lvl = DBGLVL_ERR;
 667                         if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
 668                                 dbg_lvl = DBGLVL_DEBUG;
 669                         }
 670                         DBG_PREFIX(dbg_lvl, (
 671                                    "synthetic_pathref failed for %s, error %s\n",
 672                                    filepath,
 673                                    nt_errstr(status)));
 674                         TALLOC_FREE(fname);
 675                         TALLOC_FREE(filepath);
 676                         return false;
 677                 }
 678
 679                 status = smbd_check_access_rights_fsp(fsp->conn->cwd_fsp,
 680                                                   fname->fsp,
 681                                                   false,
 682                                                   rights);
 683                 if (!NT_STATUS_IS_OK(status)) {
 684                         DBG_DEBUG("Access rights for %s/%s: %s\n",
 685                                   fsp->conn->connectpath,
 686                                   filepath,
 687                                   nt_errstr(status));
 688                         TALLOC_FREE(fname);
 689                         TALLOC_FREE(filepath);
 690                         return false;
 691                 }
 692
 693                 TALLOC_FREE(fname);
 694                 rights = SEC_DIR_TRAVERSE;
 695                 p = strrchr_m(filepath, '/');
 696         }
 697
 698         TALLOC_FREE(filepath);
 699
 700         /* Finally check share root. */
 701         filepath = talloc_strdup(talloc_tos(), ".");
 702         if (filepath == NULL) {
 703                 DBG_ERR("Memory allocation failed\n");
 704                 return false;
 705         }
 706         status = synthetic_pathref(talloc_tos(),
 707                                    fsp->conn->cwd_fsp,
 708                                    filepath,
 709                                    NULL,
 710                                    NULL,
 711                                    0,
 712                                    0,
 713                                    &fname);
 714         if (!NT_STATUS_IS_OK(status)) {
 715                 DBG_ERR("synthetic_pathref failed for %s, error %s\n",
 716                         filepath,
 717                         nt_errstr(status));
 718                 TALLOC_FREE(fname);
 719                 TALLOC_FREE(filepath);
 720                 return false;
 721         }
 722         status = smbd_check_access_rights_fsp(fsp->conn->cwd_fsp,
 723                                           fname->fsp,
 724                                           false,
 725                                           rights);
 726         if (!NT_STATUS_IS_OK(status)) {
 727                 DBG_DEBUG("TRAVERSE access rights for %s failed with %s\n",
 728                           fsp->conn->connectpath,
 729                           nt_errstr(status));
 730                 TALLOC_FREE(fname);
 731                 TALLOC_FREE(filepath);
 732                 return false;
 733         }
 734         TALLOC_FREE(fname);
 735         TALLOC_FREE(filepath);
 736         return true;
 737 }
 738
 739 static void notify_fsp(files_struct *fsp, struct timespec when,
 740                        uint32_t action, const char *name)
 741 {
 742         struct notify_change_event *change, *changes;
 743         char *tmp;
 744
 745         if (fsp->notify == NULL) {
 746                 /*
 747                  * Nobody is waiting, don't queue
 748                  */
 749                 return;
 750         }
 751
 752         if (lp_honor_change_notify_privilege(SNUM(fsp->conn))) {
 753                 bool has_sec_change_notify_privilege;
 754                 bool expose = false;
 755
 756                 has_sec_change_notify_privilege = security_token_has_privilege(
 757                         fsp->conn->session_info->security_token,
 758                         SEC_PRIV_CHANGE_NOTIFY);
 759
 760                 if (has_sec_change_notify_privilege) {
 761                         expose = true;
 762                 } else {
 763                         bool ok;
 764
 765                         ok = become_user_without_service_by_fsp(fsp);
 766                         if (ok) {
 767                                 expose = user_can_stat_name_under_fsp(fsp, name);
 768                                 unbecome_user_without_service();
 769                         }
 770                 }
 771                 DBG_DEBUG("has_sec_change_notify_privilege=%s "
 772                           "expose=%s for %s notify %s\n",
 773                           has_sec_change_notify_privilege ? "true" : "false",
 774                           expose ? "true" : "false",
 775                           fsp->fsp_name->base_name, name);
 776                 if (!expose) {
 777                         return;
 778                 }
 779         }
 780
 781         /*
 782          * Someone has triggered a notify previously, queue the change for
 783          * later.
 784          */
 785
 786         if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
 787                 /*
 788                  * The real number depends on the client buf, just provide a
 789                  * guard against a DoS here.  If name == NULL the CN backend is
 790                  * alerting us to a problem.  Possibly dropped events.  Clear
 791                  * queued changes and send the catch-all response to the client
 792                  * if a request is pending.
 793                  */
 794                 TALLOC_FREE(fsp->notify->changes);
 795                 fsp->notify->num_changes = -1;
 796                 if (fsp->notify->requests != NULL) {
 797                         change_notify_reply(fsp->notify->requests->req,
 798                                             NT_STATUS_OK,
 799                                             fsp->notify->requests->max_param,
 800                                             fsp->notify,
 801                                             fsp->notify->requests->reply_fn);
 802                         change_notify_remove_request(fsp->conn->sconn,
 803                                                      fsp->notify->requests);
 804                 }
 805                 return;
 806         }
 807
 808         /* If we've exceeded the server side queue or received a NULL name
 809          * from the underlying CN implementation, don't queue up any more
 810          * requests until we can send a catch-all response to the client */
 811         if (fsp->notify->num_changes == -1) {
 812                 return;
 813         }
 814
 815         if (!(changes = talloc_realloc(
 816                       fsp->notify, fsp->notify->changes,
 817                       struct notify_change_event,
 818                       fsp->notify->num_changes+1))) {
 819                 DEBUG(0, ("talloc_realloc failed\n"));
 820                 return;
 821         }
 822
 823         fsp->notify->changes = changes;
 824
 825         change = &(fsp->notify->changes[fsp->notify->num_changes]);
 826
 827         if (!(tmp = talloc_strdup(changes, name))) {
 828                 DEBUG(0, ("talloc_strdup failed\n"));
 829                 return;
 830         }
 831
 832         string_replace(tmp, '/', '\\');
 833         change->name = tmp;
 834
 835         change->when = when;
 836         change->action = action;
 837         fsp->notify->num_changes += 1;
 838
 839         if (fsp->notify->requests == NULL) {
 840                 /*
 841                  * Nobody is waiting, so don't send anything. The ot
 842                  */
 843                 return;
 844         }
 845
 846         if (action == NOTIFY_ACTION_OLD_NAME) {
 847                 /*
 848                  * We have to send the two rename events in one reply. So hold
 849                  * the first part back.
 850                  */
 851                 return;
 852         }
 853
 854         /*
 855          * Someone is waiting for the change, trigger the reply immediately.
 856          *
 857          * TODO: do we have to walk the lists of requests pending?
 858          */
 859
 860         change_notify_reply(fsp->notify->requests->req,
 861                             NT_STATUS_OK,
 862                             fsp->notify->requests->max_param,
 863                             fsp->notify,
 864                             fsp->notify->requests->reply_fn);
 865
 866         change_notify_remove_request(fsp->conn->sconn, fsp->notify->requests);
 867 }
 868
 869 char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32_t filter)
 870 {
 871         char *result = NULL;
 872
 873         result = talloc_strdup(mem_ctx, "");
 874
 875         if (filter & FILE_NOTIFY_CHANGE_FILE_NAME) {
 876                 talloc_asprintf_addbuf(&result, "FILE_NAME|");
 877         }
 878         if (filter & FILE_NOTIFY_CHANGE_DIR_NAME) {
 879                 talloc_asprintf_addbuf(&result, "DIR_NAME|");
 880         }
 881         if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES) {
 882                 talloc_asprintf_addbuf(&result, "ATTRIBUTES|");
 883         }
 884         if (filter & FILE_NOTIFY_CHANGE_SIZE) {
 885                 talloc_asprintf_addbuf(&result, "SIZE|");
 886         }
 887         if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE) {
 888                 talloc_asprintf_addbuf(&result, "LAST_WRITE|");
 889         }
 890         if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS) {
 891                 talloc_asprintf_addbuf(&result, "LAST_ACCESS|");
 892         }
 893         if (filter & FILE_NOTIFY_CHANGE_CREATION) {
 894                 talloc_asprintf_addbuf(&result, "CREATION|");
 895         }
 896         if (filter & FILE_NOTIFY_CHANGE_EA) {
 897                 talloc_asprintf_addbuf(&result, "EA|");
 898         }
 899         if (filter & FILE_NOTIFY_CHANGE_SECURITY) {
 900                 talloc_asprintf_addbuf(&result, "SECURITY|");
 901         }
 902         if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME) {
 903                 talloc_asprintf_addbuf(&result, "STREAM_NAME|");
 904         }
 905         if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE) {
 906                 talloc_asprintf_addbuf(&result, "STREAM_SIZE|");
 907         }
 908         if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE) {
 909                 talloc_asprintf_addbuf(&result, "STREAM_WRITE|");
 910         }
 911
 912         if (result == NULL) {
 913                 return NULL;
 914         }
 915
 916         if (*result == '\0') return result;
 917
 918         result[strlen(result)-1] = '\0';
 919         return result;
 920 }
 921
 922 struct sys_notify_context *sys_notify_context_create(TALLOC_CTX *mem_ctx,
 923                                                      struct tevent_context *ev)
 924 {
 925         struct sys_notify_context *ctx;
 926
 927         if (!(ctx = talloc(mem_ctx, struct sys_notify_context))) {
 928                 DEBUG(0, ("talloc failed\n"));
 929                 return NULL;
 930         }
 931
 932         ctx->ev = ev;
 933         ctx->private_data = NULL;
 934         return ctx;
 935 }