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         if (!(fsp->access_mask & SEC_DIR_LIST)) {
 299                 return NT_STATUS_ACCESS_DENIED;
 300         }
 301
 302         if (fsp->notify != NULL) {
 303                 DEBUG(1, ("change_notify_create: fsp->notify != NULL, "
 304                           "fname = %s\n", fsp->fsp_name->base_name));
 305                 return NT_STATUS_INVALID_PARAMETER;
 306         }
 307
 308         if (!(fsp->notify = talloc_zero(NULL, struct notify_change_buf))) {
 309                 DEBUG(0, ("talloc failed\n"));
 310                 return NT_STATUS_NO_MEMORY;
 311         }
 312         fsp->notify->filter = filter;
 313         fsp->notify->subdir_filter = recursive ? filter : 0;
 314         fsp->notify->max_buffer_size = max_buffer_size;
 315
 316         fsp_fullbasepath(fsp, fullpath, sizeof(fullpath));
 317
 318         /*
 319          * Avoid /. at the end of the path name. notify can't deal with it.
 320          */
 321         if (len > 1 && fullpath[len-1] == '.' && fullpath[len-2] == '/') {
 322                 fullpath[len-2] = '\0';
 323         }
 324
 325         if ((fsp->notify->filter != 0) ||
 326             (fsp->notify->subdir_filter != 0)) {
 327                 status = notify_add(fsp->conn->sconn->notify_ctx,
 328                                     fullpath, fsp->notify->filter,
 329                                     fsp->notify->subdir_filter, fsp);
 330         }
 331
 332         return status;
 333 }
 334
 335 NTSTATUS change_notify_add_request(struct smb_request *req,
 336                                 uint32_t max_param,
 337                                 uint32_t filter, bool recursive,
 338                                 struct files_struct *fsp,
 339                                 void (*reply_fn)(struct smb_request *req,
 340                                         NTSTATUS error_code,
 341                                         uint8_t *buf, size_t len))
 342 {
 343         struct notify_change_request *request = NULL;
 344         struct notify_mid_map *map = NULL;
 345         struct smbd_server_connection *sconn = req->sconn;
 346
 347         DEBUG(10, ("change_notify_add_request: Adding request for %s: "
 348                    "max_param = %d\n", fsp_str_dbg(fsp), (int)max_param));
 349
 350         if (!(request = talloc(NULL, struct notify_change_request))
 351             || !(map = talloc(request, struct notify_mid_map))) {
 352                 TALLOC_FREE(request);
 353                 return NT_STATUS_NO_MEMORY;
 354         }
 355
 356         request->mid_map = map;
 357         map->req = request;
 358
 359         request->req = talloc_move(request, &req);
 360         request->max_param = max_param;
 361         request->filter = filter;
 362         request->fsp = fsp;
 363         request->reply_fn = reply_fn;
 364         request->backend_data = NULL;
 365
 366         DLIST_ADD_END(fsp->notify->requests, request);
 367
 368         map->mid = request->req->mid;
 369         DLIST_ADD(sconn->notify_mid_maps, map);
 370
 371         return NT_STATUS_OK;
 372 }
 373
 374 static void change_notify_remove_request(struct smbd_server_connection *sconn,
 375                                          struct notify_change_request *remove_req)
 376 {
 377         files_struct *fsp;
 378         struct notify_change_request *req;
 379
 380         /*
 381          * Paranoia checks, the fsp referenced must must have the request in
 382          * its list of pending requests
 383          */
 384
 385         fsp = remove_req->fsp;
 386         SMB_ASSERT(fsp->notify != NULL);
 387
 388         for (req = fsp->notify->requests; req; req = req->next) {
 389                 if (req == remove_req) {
 390                         break;
 391                 }
 392         }
 393
 394         if (req == NULL) {
 395                 smb_panic("notify_req not found in fsp's requests");
 396         }
 397
 398         DLIST_REMOVE(fsp->notify->requests, req);
 399         DLIST_REMOVE(sconn->notify_mid_maps, req->mid_map);
 400         TALLOC_FREE(req);
 401 }
 402
 403 static void smbd_notify_cancel_by_map(struct notify_mid_map *map)
 404 {
 405         struct smb_request *smbreq = map->req->req;
 406         struct smbd_server_connection *sconn = smbreq->sconn;
 407         struct smbd_smb2_request *smb2req = smbreq->smb2req;
 408         NTSTATUS notify_status = NT_STATUS_CANCELLED;
 409
 410         if (smb2req != NULL) {
 411                 NTSTATUS sstatus;
 412
 413                 if (smb2req->session == NULL) {
 414                         sstatus = NT_STATUS_USER_SESSION_DELETED;
 415                 } else {
 416                         sstatus = smb2req->session->status;
 417                 }
 418
 419                 if (NT_STATUS_EQUAL(sstatus, NT_STATUS_NETWORK_SESSION_EXPIRED)) {
 420                         sstatus = NT_STATUS_OK;
 421                 }
 422
 423                 if (!NT_STATUS_IS_OK(sstatus)) {
 424                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 425                 } else if (smb2req->tcon == NULL) {
 426                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 427                 } else if (!NT_STATUS_IS_OK(smb2req->tcon->status)) {
 428                         notify_status = NT_STATUS_NOTIFY_CLEANUP;
 429                 }
 430         }
 431
 432         change_notify_reply(smbreq, notify_status,
 433                             0, NULL, map->req->reply_fn);
 434         change_notify_remove_request(sconn, map->req);
 435 }
 436
 437 /****************************************************************************
 438  Delete entries by mid from the change notify pending queue. Always send reply.
 439 *****************************************************************************/
 440
 441 bool remove_pending_change_notify_requests_by_mid(
 442         struct smbd_server_connection *sconn, uint64_t mid)
 443 {
 444         struct notify_mid_map *map;
 445
 446         for (map = sconn->notify_mid_maps; map; map = map->next) {
 447                 if (map->mid == mid) {
 448                         break;
 449                 }
 450         }
 451
 452         if (map == NULL) {
 453                 return false;
 454         }
 455
 456         smbd_notify_cancel_by_map(map);
 457         return true;
 458 }
 459
 460 void smbd_notify_cancel_by_smbreq(const struct smb_request *smbreq)
 461 {
 462         struct smbd_server_connection *sconn = smbreq->sconn;
 463         struct notify_mid_map *map;
 464
 465         for (map = sconn->notify_mid_maps; map; map = map->next) {
 466                 if (map->req->req == smbreq) {
 467                         break;
 468                 }
 469         }
 470
 471         if (map == NULL) {
 472                 return;
 473         }
 474
 475         smbd_notify_cancel_by_map(map);
 476 }
 477
 478 static struct files_struct *smbd_notify_cancel_deleted_fn(
 479         struct files_struct *fsp, void *private_data)
 480 {
 481         struct file_id *fid = talloc_get_type_abort(
 482                 private_data, struct file_id);
 483
 484         if (file_id_equal(&fsp->file_id, fid)) {
 485                 remove_pending_change_notify_requests_by_fid(
 486                         fsp, NT_STATUS_DELETE_PENDING);
 487         }
 488         return NULL;
 489 }
 490
 491 void smbd_notify_cancel_deleted(struct messaging_context *msg,
 492                                 void *private_data, uint32_t msg_type,
 493                                 struct server_id server_id, DATA_BLOB *data)
 494 {
 495         struct smbd_server_connection *sconn = talloc_get_type_abort(
 496                 private_data, struct smbd_server_connection);
 497         struct file_id *fid;
 498         enum ndr_err_code ndr_err;
 499
 500         fid = talloc(talloc_tos(), struct file_id);
 501         if (fid == NULL) {
 502                 DEBUG(1, ("talloc failed\n"));
 503                 return;
 504         }
 505
 506         ndr_err = ndr_pull_struct_blob_all(
 507                 data, fid, fid, (ndr_pull_flags_fn_t)ndr_pull_file_id);
 508         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 509                 DEBUG(10, ("%s: ndr_pull_file_id failed: %s\n", __func__,
 510                            ndr_errstr(ndr_err)));
 511                 goto done;
 512         }
 513
 514         files_forall(sconn, smbd_notify_cancel_deleted_fn, fid);
 515
 516 done:
 517         TALLOC_FREE(fid);
 518 }
 519
 520 static struct files_struct *smbd_notifyd_reregister(struct files_struct *fsp,
 521                                                     void *private_data)
 522 {
 523         DBG_DEBUG("reregister %s\n", fsp->fsp_name->base_name);
 524
 525         if ((fsp->conn->sconn->notify_ctx != NULL) &&
 526             (fsp->notify != NULL) &&
 527             ((fsp->notify->filter != 0) ||
 528              (fsp->notify->subdir_filter != 0))) {
 529                 size_t len = fsp_fullbasepath(fsp, NULL, 0);
 530                 char fullpath[len+1];
 531
 532                 NTSTATUS status;
 533
 534                 fsp_fullbasepath(fsp, fullpath, sizeof(fullpath));
 535                 if (len > 1 && fullpath[len-1] == '.' &&
 536                     fullpath[len-2] == '/') {
 537                         fullpath[len-2] = '\0';
 538                 }
 539
 540                 status = notify_add(fsp->conn->sconn->notify_ctx,
 541                                     fullpath, fsp->notify->filter,
 542                                     fsp->notify->subdir_filter, fsp);
 543                 if (!NT_STATUS_IS_OK(status)) {
 544                         DBG_DEBUG("notify_add failed: %s\n",
 545                                   nt_errstr(status));
 546                 }
 547         }
 548         return NULL;
 549 }
 550
 551 void smbd_notifyd_restarted(struct messaging_context *msg,
 552                             void *private_data, uint32_t msg_type,
 553                             struct server_id server_id, DATA_BLOB *data)
 554 {
 555         struct smbd_server_connection *sconn = talloc_get_type_abort(
 556                 private_data, struct smbd_server_connection);
 557
 558         TALLOC_FREE(sconn->notify_ctx);
 559
 560         sconn->notify_ctx = notify_init(sconn, sconn->msg_ctx,
 561                                         sconn, notify_callback);
 562         if (sconn->notify_ctx == NULL) {
 563                 DBG_DEBUG("notify_init failed\n");
 564                 return;
 565         }
 566
 567         files_forall(sconn, smbd_notifyd_reregister, sconn->notify_ctx);
 568 }
 569
 570 /****************************************************************************
 571  Delete entries by fnum from the change notify pending queue.
 572 *****************************************************************************/
 573
 574 void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
 575                                                   NTSTATUS status)
 576 {
 577         if (fsp->notify == NULL) {
 578                 return;
 579         }
 580
 581         while (fsp->notify->requests != NULL) {
 582                 change_notify_reply(fsp->notify->requests->req,
 583                                     status, 0, NULL,
 584                                     fsp->notify->requests->reply_fn);
 585                 change_notify_remove_request(fsp->conn->sconn,
 586                                              fsp->notify->requests);
 587         }
 588 }
 589
 590 void notify_fname(connection_struct *conn, uint32_t action, uint32_t filter,
 591                   const char *path)
 592 {
 593         struct notify_context *notify_ctx = conn->sconn->notify_ctx;
 594
 595         if (path[0] == '.' && path[1] == '/') {
 596                 path += 2;
 597         }
 598
 599         notify_trigger(notify_ctx, action, filter, conn->connectpath, path);
 600 }
 601
 602 static bool user_can_stat_name_under_fsp(files_struct *fsp, const char *name)
 603 {
 604         uint32_t rights;
 605         struct smb_filename *fname = NULL;
 606         char *filepath = NULL;
 607         NTSTATUS status;
 608         char *p = NULL;
 609
 610         /*
 611          * Assume we get filepath (relative to the share)
 612          * like this:
 613          *
 614          *  'dir1/dir2/dir3/file'
 615          *
 616          * We start with LIST and TRAVERSE on the
 617          * direct parent ('dir1/dir2/dir3')
 618          *
 619          * Then we switch to just TRAVERSE for
 620          * the rest: 'dir1/dir2', 'dir1', '.'
 621          *
 622          * For a file in the share root, we'll have
 623          *  'file'
 624          * and would just check '.' with LIST and TRAVERSE.
 625          *
 626          * It's important to always check '.' as the last step,
 627          * which means we check the permissions of the share root
 628          * directory.
 629          */
 630
 631         if (ISDOT(fsp->fsp_name->base_name)) {
 632                 filepath = talloc_strdup(talloc_tos(), name);
 633         } else {
 634                 filepath = talloc_asprintf(talloc_tos(),
 635                         "%s/%s",
 636                         fsp->fsp_name->base_name,
 637                         name);
 638         }
 639         if (filepath == NULL) {
 640                 DBG_ERR("Memory allocation failed\n");
 641                 return false;
 642         }
 643
 644         rights = SEC_DIR_LIST|SEC_DIR_TRAVERSE;
 645         p = strrchr_m(filepath, '/');
 646         /*
 647          * Check each path component, exluding the share root.
 648          *
 649          * We could check all components including root using
 650          * a do { .. } while() loop, but IMHO the logic is clearer
 651          * having the share root check separately afterwards.
 652          */
 653         while (p != NULL) {
 654                 *p = '\0';
 655                 status = synthetic_pathref(talloc_tos(),
 656                                            fsp->conn->cwd_fsp,
 657                                            filepath,
 658                                            NULL,
 659                                            NULL,
 660                                            0,
 661                                            0,
 662                                            &fname);
 663                 if (!NT_STATUS_IS_OK(status)) {
 664                         DBG_ERR("synthetic_pathref failed for %s, error %s\n",
 665                                 filepath,
 666                                 nt_errstr(status));
 667                         TALLOC_FREE(fname);
 668                         TALLOC_FREE(filepath);
 669                         return false;
 670                 }
 671
 672                 status = smbd_check_access_rights_fsp(fsp->conn->cwd_fsp,
 673                                                   fname->fsp,
 674                                                   false,
 675                                                   rights);
 676                 if (!NT_STATUS_IS_OK(status)) {
 677                         DBG_DEBUG("Access rights for %s/%s: %s\n",
 678                                   fsp->conn->connectpath,
 679                                   filepath,
 680                                   nt_errstr(status));
 681                         TALLOC_FREE(fname);
 682                         TALLOC_FREE(filepath);
 683                         return false;
 684                 }
 685
 686                 TALLOC_FREE(fname);
 687                 rights = SEC_DIR_TRAVERSE;
 688                 p = strrchr_m(filepath, '/');
 689         }
 690
 691         TALLOC_FREE(filepath);
 692
 693         /* Finally check share root. */
 694         filepath = talloc_strdup(talloc_tos(), ".");
 695         if (filepath == NULL) {
 696                 DBG_ERR("Memory allocation failed\n");
 697                 return false;
 698         }
 699         status = synthetic_pathref(talloc_tos(),
 700                                    fsp->conn->cwd_fsp,
 701                                    filepath,
 702                                    NULL,
 703                                    NULL,
 704                                    0,
 705                                    0,
 706                                    &fname);
 707         if (!NT_STATUS_IS_OK(status)) {
 708                 DBG_ERR("synthetic_pathref failed for %s, error %s\n",
 709                         filepath,
 710                         nt_errstr(status));
 711                 TALLOC_FREE(fname);
 712                 TALLOC_FREE(filepath);
 713                 return false;
 714         }
 715         status = smbd_check_access_rights_fsp(fsp->conn->cwd_fsp,
 716                                           fname->fsp,
 717                                           false,
 718                                           rights);
 719         if (!NT_STATUS_IS_OK(status)) {
 720                 DBG_DEBUG("TRAVERSE access rights for %s failed with %s\n",
 721                           fsp->conn->connectpath,
 722                           nt_errstr(status));
 723                 TALLOC_FREE(fname);
 724                 TALLOC_FREE(filepath);
 725                 return false;
 726         }
 727         TALLOC_FREE(fname);
 728         TALLOC_FREE(filepath);
 729         return true;
 730 }
 731
 732 static void notify_fsp(files_struct *fsp, struct timespec when,
 733                        uint32_t action, const char *name)
 734 {
 735         struct notify_change_event *change, *changes;
 736         char *tmp;
 737
 738         if (fsp->notify == NULL) {
 739                 /*
 740                  * Nobody is waiting, don't queue
 741                  */
 742                 return;
 743         }
 744
 745         if (lp_honor_change_notify_privilege(SNUM(fsp->conn))) {
 746                 bool has_sec_change_notify_privilege;
 747                 bool expose = false;
 748
 749                 has_sec_change_notify_privilege = security_token_has_privilege(
 750                         fsp->conn->session_info->security_token,
 751                         SEC_PRIV_CHANGE_NOTIFY);
 752
 753                 if (has_sec_change_notify_privilege) {
 754                         expose = true;
 755                 } else {
 756                         bool ok;
 757
 758                         ok = become_user_without_service_by_fsp(fsp);
 759                         if (ok) {
 760                                 expose = user_can_stat_name_under_fsp(fsp, name);
 761                                 unbecome_user_without_service();
 762                         }
 763                 }
 764                 DBG_DEBUG("has_sec_change_notify_privilege=%s "
 765                           "expose=%s for %s notify %s\n",
 766                           has_sec_change_notify_privilege ? "true" : "false",
 767                           expose ? "true" : "false",
 768                           fsp->fsp_name->base_name, name);
 769                 if (!expose) {
 770                         return;
 771                 }
 772         }
 773
 774         /*
 775          * Someone has triggered a notify previously, queue the change for
 776          * later.
 777          */
 778
 779         if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
 780                 /*
 781                  * The real number depends on the client buf, just provide a
 782                  * guard against a DoS here.  If name == NULL the CN backend is
 783                  * alerting us to a problem.  Possibly dropped events.  Clear
 784                  * queued changes and send the catch-all response to the client
 785                  * if a request is pending.
 786                  */
 787                 TALLOC_FREE(fsp->notify->changes);
 788                 fsp->notify->num_changes = -1;
 789                 if (fsp->notify->requests != NULL) {
 790                         change_notify_reply(fsp->notify->requests->req,
 791                                             NT_STATUS_OK,
 792                                             fsp->notify->requests->max_param,
 793                                             fsp->notify,
 794                                             fsp->notify->requests->reply_fn);
 795                         change_notify_remove_request(fsp->conn->sconn,
 796                                                      fsp->notify->requests);
 797                 }
 798                 return;
 799         }
 800
 801         /* If we've exceeded the server side queue or received a NULL name
 802          * from the underlying CN implementation, don't queue up any more
 803          * requests until we can send a catch-all response to the client */
 804         if (fsp->notify->num_changes == -1) {
 805                 return;
 806         }
 807
 808         if (!(changes = talloc_realloc(
 809                       fsp->notify, fsp->notify->changes,
 810                       struct notify_change_event,
 811                       fsp->notify->num_changes+1))) {
 812                 DEBUG(0, ("talloc_realloc failed\n"));
 813                 return;
 814         }
 815
 816         fsp->notify->changes = changes;
 817
 818         change = &(fsp->notify->changes[fsp->notify->num_changes]);
 819
 820         if (!(tmp = talloc_strdup(changes, name))) {
 821                 DEBUG(0, ("talloc_strdup failed\n"));
 822                 return;
 823         }
 824
 825         string_replace(tmp, '/', '\\');
 826         change->name = tmp;
 827
 828         change->when = when;
 829         change->action = action;
 830         fsp->notify->num_changes += 1;
 831
 832         if (fsp->notify->requests == NULL) {
 833                 /*
 834                  * Nobody is waiting, so don't send anything. The ot
 835                  */
 836                 return;
 837         }
 838
 839         if (action == NOTIFY_ACTION_OLD_NAME) {
 840                 /*
 841                  * We have to send the two rename events in one reply. So hold
 842                  * the first part back.
 843                  */
 844                 return;
 845         }
 846
 847         /*
 848          * Someone is waiting for the change, trigger the reply immediately.
 849          *
 850          * TODO: do we have to walk the lists of requests pending?
 851          */
 852
 853         change_notify_reply(fsp->notify->requests->req,
 854                             NT_STATUS_OK,
 855                             fsp->notify->requests->max_param,
 856                             fsp->notify,
 857                             fsp->notify->requests->reply_fn);
 858
 859         change_notify_remove_request(fsp->conn->sconn, fsp->notify->requests);
 860 }
 861
 862 char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32_t filter)
 863 {
 864         char *result = NULL;
 865
 866         result = talloc_strdup(mem_ctx, "");
 867
 868         if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
 869                 result = talloc_asprintf_append(result, "FILE_NAME|");
 870         if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
 871                 result = talloc_asprintf_append(result, "DIR_NAME|");
 872         if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
 873                 result = talloc_asprintf_append(result, "ATTRIBUTES|");
 874         if (filter & FILE_NOTIFY_CHANGE_SIZE)
 875                 result = talloc_asprintf_append(result, "SIZE|");
 876         if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
 877                 result = talloc_asprintf_append(result, "LAST_WRITE|");
 878         if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
 879                 result = talloc_asprintf_append(result, "LAST_ACCESS|");
 880         if (filter & FILE_NOTIFY_CHANGE_CREATION)
 881                 result = talloc_asprintf_append(result, "CREATION|");
 882         if (filter & FILE_NOTIFY_CHANGE_EA)
 883                 result = talloc_asprintf_append(result, "EA|");
 884         if (filter & FILE_NOTIFY_CHANGE_SECURITY)
 885                 result = talloc_asprintf_append(result, "SECURITY|");
 886         if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
 887                 result = talloc_asprintf_append(result, "STREAM_NAME|");
 888         if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
 889                 result = talloc_asprintf_append(result, "STREAM_SIZE|");
 890         if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
 891                 result = talloc_asprintf_append(result, "STREAM_WRITE|");
 892
 893         if (result == NULL) return NULL;
 894         if (*result == '\0') return result;
 895
 896         result[strlen(result)-1] = '\0';
 897         return result;
 898 }
 899
 900 struct sys_notify_context *sys_notify_context_create(TALLOC_CTX *mem_ctx,
 901                                                      struct tevent_context *ev)
 902 {
 903         struct sys_notify_context *ctx;
 904
 905         if (!(ctx = talloc(mem_ctx, struct sys_notify_context))) {
 906                 DEBUG(0, ("talloc failed\n"));
 907                 return NULL;
 908         }
 909
 910         ctx->ev = ev;
 911         ctx->private_data = NULL;
 912         return ctx;
 913 }