source3/smbd/blocking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Blocking Locking functions
   4    Copyright (C) Jeremy Allison 1998-2003
   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 #include "includes.h"
  21 #include "smbd/smbd.h"
  22 #include "smbd/globals.h"
  23 #include "messages.h"
  24
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_LOCKING
  27
  28 /****************************************************************************
  29  Determine if this is a secondary element of a chained SMB.
  30   **************************************************************************/
  31
  32 static void received_unlock_msg(struct messaging_context *msg,
  33                                 void *private_data,
  34                                 uint32_t msg_type,
  35                                 struct server_id server_id,
  36                                 DATA_BLOB *data);
  37
  38 void brl_timeout_fn(struct event_context *event_ctx,
  39                            struct timed_event *te,
  40                            struct timeval now,
  41                            void *private_data)
  42 {
  43         struct smbd_server_connection *sconn = talloc_get_type_abort(
  44                 private_data, struct smbd_server_connection);
  45
  46         if (sconn->using_smb2) {
  47                 SMB_ASSERT(sconn->smb2.locks.brl_timeout == te);
  48                 TALLOC_FREE(sconn->smb2.locks.brl_timeout);
  49         } else {
  50                 SMB_ASSERT(sconn->smb1.locks.brl_timeout == te);
  51                 TALLOC_FREE(sconn->smb1.locks.brl_timeout);
  52         }
  53
  54         change_to_root_user();  /* TODO: Possibly run all timed events as
  55                                  * root */
  56
  57         process_blocking_lock_queue(sconn);
  58 }
  59
  60 /****************************************************************************
  61  We need a version of timeval_min that treats zero timval as infinite.
  62 ****************************************************************************/
  63
  64 struct timeval timeval_brl_min(const struct timeval *tv1,
  65                                         const struct timeval *tv2)
  66 {
  67         if (timeval_is_zero(tv1)) {
  68                 return *tv2;
  69         }
  70         if (timeval_is_zero(tv2)) {
  71                 return *tv1;
  72         }
  73         return timeval_min(tv1, tv2);
  74 }
  75
  76 /****************************************************************************
  77  After a change to blocking_lock_queue, recalculate the timed_event for the
  78  next processing.
  79 ****************************************************************************/
  80
  81 static bool recalc_brl_timeout(struct smbd_server_connection *sconn)
  82 {
  83         struct blocking_lock_record *blr;
  84         struct timeval next_timeout;
  85         int max_brl_timeout = lp_parm_int(-1, "brl", "recalctime", 5);
  86
  87         TALLOC_FREE(sconn->smb1.locks.brl_timeout);
  88
  89         next_timeout = timeval_zero();
  90
  91         for (blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = blr->next) {
  92                 if (timeval_is_zero(&blr->expire_time)) {
  93                         /*
  94                          * If we're blocked on pid 0xFFFFFFFFFFFFFFFFLL this is
  95                          * a POSIX lock, so calculate a timeout of
  96                          * 10 seconds into the future.
  97                          */
  98                         if (blr->blocking_smblctx == 0xFFFFFFFFFFFFFFFFLL) {
  99                                 struct timeval psx_to = timeval_current_ofs(10, 0);
 100                                 next_timeout = timeval_brl_min(&next_timeout, &psx_to);
 101                         }
 102
 103                         continue;
 104                 }
 105
 106                 next_timeout = timeval_brl_min(&next_timeout, &blr->expire_time);
 107         }
 108
 109         if (timeval_is_zero(&next_timeout)) {
 110                 DEBUG(10, ("Next timeout = Infinite.\n"));
 111                 return True;
 112         }
 113
 114         /*
 115          to account for unclean shutdowns by clients we need a
 116          maximum timeout that we use for checking pending locks. If
 117          we have any pending locks at all, then check if the pending
 118          lock can continue at least every brl:recalctime seconds
 119          (default 5 seconds).
 120
 121          This saves us needing to do a message_send_all() in the
 122          SIGCHLD handler in the parent daemon. That
 123          message_send_all() caused O(n^2) work to be done when IP
 124          failovers happened in clustered Samba, which could make the
 125          entire system unusable for many minutes.
 126         */
 127
 128         if (max_brl_timeout > 0) {
 129                 struct timeval min_to = timeval_current_ofs(max_brl_timeout, 0);
 130                 next_timeout = timeval_min(&next_timeout, &min_to);
 131         }
 132
 133         if (DEBUGLVL(10)) {
 134                 struct timeval cur, from_now;
 135
 136                 cur = timeval_current();
 137                 from_now = timeval_until(&cur, &next_timeout);
 138                 DEBUG(10, ("Next timeout = %d.%d seconds from now.\n",
 139                     (int)from_now.tv_sec, (int)from_now.tv_usec));
 140         }
 141
 142         sconn->smb1.locks.brl_timeout = tevent_add_timer(sconn->ev_ctx,
 143                                                          NULL, next_timeout,
 144                                                          brl_timeout_fn, sconn);
 145         if (sconn->smb1.locks.brl_timeout == NULL) {
 146                 return False;
 147         }
 148
 149         return True;
 150 }
 151
 152
 153 /****************************************************************************
 154  Function to push a blocking lock request onto the lock queue.
 155 ****************************************************************************/
 156
 157 bool push_blocking_lock_request( struct byte_range_lock *br_lck,
 158                 struct smb_request *req,
 159                 files_struct *fsp,
 160                 int lock_timeout,
 161                 int lock_num,
 162                 uint64_t smblctx,
 163                 enum brl_type lock_type,
 164                 enum brl_flavour lock_flav,
 165                 uint64_t offset,
 166                 uint64_t count,
 167                 uint64_t blocking_smblctx)
 168 {
 169         struct smbd_server_connection *sconn = req->sconn;
 170         struct blocking_lock_record *blr;
 171         NTSTATUS status;
 172
 173         if (req->smb2req) {
 174                 return push_blocking_lock_request_smb2(br_lck,
 175                                 req,
 176                                 fsp,
 177                                 lock_timeout,
 178                                 lock_num,
 179                                 smblctx,
 180                                 lock_type,
 181                                 lock_flav,
 182                                 offset,
 183                                 count,
 184                                 blocking_smblctx);
 185         }
 186
 187         if(req_is_in_chain(req)) {
 188                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 189                 return False;
 190         }
 191
 192         /*
 193          * Now queue an entry on the blocking lock queue. We setup
 194          * the expiration time here.
 195          */
 196
 197         blr = talloc(NULL, struct blocking_lock_record);
 198         if (blr == NULL) {
 199                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 200                 return False;
 201         }
 202
 203         blr->next = NULL;
 204         blr->prev = NULL;
 205
 206         blr->fsp = fsp;
 207         if (lock_timeout == -1) {
 208                 blr->expire_time.tv_sec = 0;
 209                 blr->expire_time.tv_usec = 0; /* Never expire. */
 210         } else {
 211                 blr->expire_time = timeval_current_ofs_msec(lock_timeout);
 212         }
 213         blr->lock_num = lock_num;
 214         blr->smblctx = smblctx;
 215         blr->blocking_smblctx = blocking_smblctx;
 216         blr->lock_flav = lock_flav;
 217         blr->lock_type = lock_type;
 218         blr->offset = offset;
 219         blr->count = count;
 220
 221         /* Specific brl_lock() implementations can fill this in. */
 222         blr->blr_private = NULL;
 223
 224         /* Add a pending lock record for this. */
 225         status = brl_lock(req->sconn->msg_ctx,
 226                         br_lck,
 227                         smblctx,
 228                         sconn_server_id(req->sconn),
 229                         offset,
 230                         count,
 231                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 232                         blr->lock_flav,
 233                         True,
 234                         NULL,
 235                         blr);
 236
 237         if (!NT_STATUS_IS_OK(status)) {
 238                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 239                 TALLOC_FREE(blr);
 240                 return False;
 241         }
 242
 243         SMB_PERFCOUNT_DEFER_OP(&req->pcd, &req->pcd);
 244         blr->req = talloc_move(blr, &req);
 245
 246         DLIST_ADD_END(sconn->smb1.locks.blocking_lock_queue, blr, struct blocking_lock_record *);
 247         recalc_brl_timeout(sconn);
 248
 249         /* Ensure we'll receive messages when this is unlocked. */
 250         if (!sconn->smb1.locks.blocking_lock_unlock_state) {
 251                 messaging_register(sconn->msg_ctx, sconn,
 252                                    MSG_SMB_UNLOCK, received_unlock_msg);
 253                 sconn->smb1.locks.blocking_lock_unlock_state = true;
 254         }
 255
 256         DEBUG(3,("push_blocking_lock_request: lock request blocked with "
 257                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 258                 (unsigned int)blr->expire_time.tv_sec,
 259                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 260                 blr->fsp->fnum, fsp_str_dbg(blr->fsp)));
 261
 262         return True;
 263 }
 264
 265 /****************************************************************************
 266  Return a lockingX success SMB.
 267 *****************************************************************************/
 268
 269 static void reply_lockingX_success(struct blocking_lock_record *blr)
 270 {
 271         reply_outbuf(blr->req, 2, 0);
 272
 273         /*
 274          * As this message is a lockingX call we must handle
 275          * any following chained message correctly.
 276          * This is normally handled in construct_reply(),
 277          * but as that calls switch_message, we can't use
 278          * that here and must set up the chain info manually.
 279          */
 280
 281         chain_reply(blr->req);
 282         TALLOC_FREE(blr->req->outbuf);
 283 }
 284
 285 /****************************************************************************
 286  Return a generic lock fail error blocking call.
 287 *****************************************************************************/
 288
 289 static void generic_blocking_lock_error(struct blocking_lock_record *blr, NTSTATUS status)
 290 {
 291         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 292            FILE_LOCK_CONFLICT! (tridge) */
 293         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 294                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 295         }
 296
 297         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 298                 /* Store the last lock error. */
 299                 files_struct *fsp = blr->fsp;
 300
 301                 if (fsp) {
 302                         fsp->last_lock_failure.context.smblctx = blr->smblctx;
 303                         fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 304                         fsp->last_lock_failure.context.pid =
 305                                 sconn_server_id(fsp->conn->sconn);
 306                         fsp->last_lock_failure.start = blr->offset;
 307                         fsp->last_lock_failure.size = blr->count;
 308                         fsp->last_lock_failure.fnum = fsp->fnum;
 309                         fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 310                         fsp->last_lock_failure.lock_flav = blr->lock_flav;
 311                 }
 312         }
 313
 314         reply_nterror(blr->req, status);
 315         if (!srv_send_smb(blr->req->sconn, (char *)blr->req->outbuf,
 316                           true, blr->req->seqnum+1,
 317                           blr->req->encrypted, NULL)) {
 318                 exit_server_cleanly("generic_blocking_lock_error: srv_send_smb failed.");
 319         }
 320         TALLOC_FREE(blr->req->outbuf);
 321 }
 322
 323 /****************************************************************************
 324  Return a lock fail error for a lockingX call. Undo all the locks we have
 325  obtained first.
 326 *****************************************************************************/
 327
 328 static void reply_lockingX_error(struct blocking_lock_record *blr, NTSTATUS status)
 329 {
 330         files_struct *fsp = blr->fsp;
 331         uint16 num_ulocks = SVAL(blr->req->vwv+6, 0);
 332         uint64_t count = (uint64_t)0, offset = (uint64_t) 0;
 333         uint64_t smblctx;
 334         unsigned char locktype = CVAL(blr->req->vwv+3, 0);
 335         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 336         uint8_t *data;
 337         int i;
 338
 339         data = discard_const_p(uint8_t, blr->req->buf)
 340                 + ((large_file_format ? 20 : 10)*num_ulocks);
 341
 342         /*
 343          * Data now points at the beginning of the list
 344          * of smb_lkrng structs.
 345          */
 346
 347         /*
 348          * Ensure we don't do a remove on the lock that just failed,
 349          * as under POSIX rules, if we have a lock already there, we
 350          * will delete it (and we shouldn't) .....
 351          */
 352
 353         for(i = blr->lock_num - 1; i >= 0; i--) {
 354                 bool err;
 355
 356                 smblctx = get_lock_pid( data, i, large_file_format);
 357                 count = get_lock_count( data, i, large_file_format);
 358                 offset = get_lock_offset( data, i, large_file_format, &err);
 359
 360                 /*
 361                  * We know err cannot be set as if it was the lock
 362                  * request would never have been queued. JRA.
 363                  */
 364
 365                 do_unlock(fsp->conn->sconn->msg_ctx,
 366                         fsp,
 367                         smblctx,
 368                         count,
 369                         offset,
 370                         WINDOWS_LOCK);
 371         }
 372
 373         generic_blocking_lock_error(blr, status);
 374 }
 375
 376 /****************************************************************************
 377  Return a lock fail error.
 378 *****************************************************************************/
 379
 380 static void blocking_lock_reply_error(struct blocking_lock_record *blr, NTSTATUS status)
 381 {
 382         DEBUG(10, ("Replying with error=%s. BLR = %p\n", nt_errstr(status), blr));
 383
 384         switch(blr->req->cmd) {
 385         case SMBlockingX:
 386                 reply_lockingX_error(blr, status);
 387                 break;
 388         case SMBtrans2:
 389         case SMBtranss2:
 390                 reply_nterror(blr->req, status);
 391
 392                 /*
 393                  * construct_reply_common has done us the favor to pre-fill
 394                  * the command field with SMBtranss2 which is wrong :-)
 395                  */
 396                 SCVAL(blr->req->outbuf,smb_com,SMBtrans2);
 397
 398                 if (!srv_send_smb(blr->req->sconn,
 399                                   (char *)blr->req->outbuf,
 400                                   true, blr->req->seqnum+1,
 401                                   IS_CONN_ENCRYPTED(blr->fsp->conn),
 402                                   NULL)) {
 403                         exit_server_cleanly("blocking_lock_reply_error: "
 404                                             "srv_send_smb failed.");
 405                 }
 406                 TALLOC_FREE(blr->req->outbuf);
 407                 break;
 408         default:
 409                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 410                 exit_server("PANIC - unknown type on blocking lock queue");
 411         }
 412 }
 413
 414 /****************************************************************************
 415  Attempt to finish off getting all pending blocking locks for a lockingX call.
 416  Returns True if we want to be removed from the list.
 417 *****************************************************************************/
 418
 419 static bool process_lockingX(struct blocking_lock_record *blr)
 420 {
 421         unsigned char locktype = CVAL(blr->req->vwv+3, 0);
 422         files_struct *fsp = blr->fsp;
 423         uint16 num_ulocks = SVAL(blr->req->vwv+6, 0);
 424         uint16 num_locks = SVAL(blr->req->vwv+7, 0);
 425         uint64_t count = (uint64_t)0, offset = (uint64_t)0;
 426         uint64_t smblctx;
 427         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 428         uint8_t *data;
 429         NTSTATUS status = NT_STATUS_OK;
 430
 431         data = discard_const_p(uint8_t, blr->req->buf)
 432                 + ((large_file_format ? 20 : 10)*num_ulocks);
 433
 434         /*
 435          * Data now points at the beginning of the list
 436          * of smb_lkrng structs.
 437          */
 438
 439         for(; blr->lock_num < num_locks; blr->lock_num++) {
 440                 struct byte_range_lock *br_lck = NULL;
 441                 bool err;
 442
 443                 smblctx = get_lock_pid( data, blr->lock_num, large_file_format);
 444                 count = get_lock_count( data, blr->lock_num, large_file_format);
 445                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 446
 447                 /*
 448                  * We know err cannot be set as if it was the lock
 449                  * request would never have been queued. JRA.
 450                  */
 451                 errno = 0;
 452                 br_lck = do_lock(fsp->conn->sconn->msg_ctx,
 453                                 fsp,
 454                                 smblctx,
 455                                 count,
 456                                 offset,
 457                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 458                                         READ_LOCK : WRITE_LOCK),
 459                                 WINDOWS_LOCK,
 460                                 True,
 461                                 &status,
 462                                 &blr->blocking_smblctx,
 463                                 blr);
 464
 465                 TALLOC_FREE(br_lck);
 466
 467                 if (NT_STATUS_IS_ERR(status)) {
 468                         break;
 469                 }
 470         }
 471
 472         if(blr->lock_num == num_locks) {
 473                 /*
 474                  * Success - we got all the locks.
 475                  */
 476
 477                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d "
 478                          "num_locks=%d\n", fsp_str_dbg(fsp), fsp->fnum,
 479                          (unsigned int)locktype, num_locks));
 480
 481                 reply_lockingX_success(blr);
 482                 return True;
 483         }
 484
 485         if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 486             !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 487                 /*
 488                  * We have other than a "can't get lock"
 489                  * error. Free any locks we had and return an error.
 490                  * Return True so we get dequeued.
 491                  */
 492                 blocking_lock_reply_error(blr, status);
 493                 return True;
 494         }
 495
 496         /*
 497          * Still can't get all the locks - keep waiting.
 498          */
 499
 500         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 501 Waiting....\n",
 502                  blr->lock_num, num_locks, fsp_str_dbg(fsp), fsp->fnum));
 503
 504         return False;
 505 }
 506
 507 /****************************************************************************
 508  Attempt to get the posix lock request from a SMBtrans2 call.
 509  Returns True if we want to be removed from the list.
 510 *****************************************************************************/
 511
 512 static bool process_trans2(struct blocking_lock_record *blr)
 513 {
 514         char params[2];
 515         NTSTATUS status;
 516         struct byte_range_lock *br_lck = do_lock(
 517                                                 blr->fsp->conn->sconn->msg_ctx,
 518                                                 blr->fsp,
 519                                                 blr->smblctx,
 520                                                 blr->count,
 521                                                 blr->offset,
 522                                                 blr->lock_type,
 523                                                 blr->lock_flav,
 524                                                 True,
 525                                                 &status,
 526                                                 &blr->blocking_smblctx,
 527                                                 blr);
 528         TALLOC_FREE(br_lck);
 529
 530         if (!NT_STATUS_IS_OK(status)) {
 531                 if (ERROR_WAS_LOCK_DENIED(status)) {
 532                         /* Still can't get the lock, just keep waiting. */
 533                         return False;
 534                 }
 535                 /*
 536                  * We have other than a "can't get lock"
 537                  * error. Send an error and return True so we get dequeued.
 538                  */
 539                 blocking_lock_reply_error(blr, status);
 540                 return True;
 541         }
 542
 543         /* We finally got the lock, return success. */
 544
 545         SSVAL(params,0,0);
 546         /* Fake up max_data_bytes here - we know it fits. */
 547         send_trans2_replies(blr->fsp->conn, blr->req, params, 2, NULL, 0, 0xffff);
 548         return True;
 549 }
 550
 551
 552 /****************************************************************************
 553  Process a blocking lock SMB.
 554  Returns True if we want to be removed from the list.
 555 *****************************************************************************/
 556
 557 static bool blocking_lock_record_process(struct blocking_lock_record *blr)
 558 {
 559         switch(blr->req->cmd) {
 560                 case SMBlockingX:
 561                         return process_lockingX(blr);
 562                 case SMBtrans2:
 563                 case SMBtranss2:
 564                         return process_trans2(blr);
 565                 default:
 566                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 567                         exit_server("PANIC - unknown type on blocking lock queue");
 568         }
 569         return False; /* Keep compiler happy. */
 570 }
 571
 572 /****************************************************************************
 573  Cancel entries by fnum from the blocking lock pending queue.
 574  Called when a file is closed.
 575 *****************************************************************************/
 576
 577 void smbd_cancel_pending_lock_requests_by_fid(files_struct *fsp,
 578                                               struct byte_range_lock *br_lck,
 579                                               enum file_close_type close_type)
 580 {
 581         struct smbd_server_connection *sconn = fsp->conn->sconn;
 582         struct blocking_lock_record *blr, *blr_cancelled, *next = NULL;
 583
 584         if (sconn->using_smb2) {
 585                 cancel_pending_lock_requests_by_fid_smb2(fsp,
 586                                         br_lck,
 587                                         close_type);
 588                 return;
 589         }
 590
 591         for(blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = next) {
 592                 unsigned char locktype = 0;
 593
 594                 next = blr->next;
 595                 if (blr->fsp->fnum != fsp->fnum) {
 596                         continue;
 597                 }
 598
 599                 if (blr->req->cmd == SMBlockingX) {
 600                         locktype = CVAL(blr->req->vwv+3, 0);
 601                 }
 602
 603                 DEBUG(10, ("remove_pending_lock_requests_by_fid - removing "
 604                            "request type %d for file %s fnum = %d\n",
 605                            blr->req->cmd, fsp_str_dbg(fsp), fsp->fnum));
 606
 607                 blr_cancelled = blocking_lock_cancel_smb1(fsp,
 608                                      blr->smblctx,
 609                                      blr->offset,
 610                                      blr->count,
 611                                      blr->lock_flav,
 612                                      locktype,
 613                                      NT_STATUS_RANGE_NOT_LOCKED);
 614
 615                 SMB_ASSERT(blr_cancelled == blr);
 616
 617                 brl_lock_cancel(br_lck,
 618                                 blr->smblctx,
 619                                 sconn_server_id(sconn),
 620                                 blr->offset,
 621                                 blr->count,
 622                                 blr->lock_flav,
 623                                 blr);
 624
 625                 /* We're closing the file fsp here, so ensure
 626                  * we don't have a dangling pointer. */
 627                 blr->fsp = NULL;
 628         }
 629 }
 630
 631 /****************************************************************************
 632  Delete entries by mid from the blocking lock pending queue. Always send reply.
 633  Only called from the SMB1 cancel code.
 634 *****************************************************************************/
 635
 636 void remove_pending_lock_requests_by_mid_smb1(
 637         struct smbd_server_connection *sconn, uint64_t mid)
 638 {
 639         struct blocking_lock_record *blr, *next = NULL;
 640
 641         for(blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = next) {
 642                 files_struct *fsp;
 643                 struct byte_range_lock *br_lck;
 644
 645                 next = blr->next;
 646
 647                 if (blr->req->mid != mid) {
 648                         continue;
 649                 }
 650
 651                 fsp = blr->fsp;
 652                 br_lck = brl_get_locks(talloc_tos(), fsp);
 653
 654                 if (br_lck) {
 655                         DEBUG(10, ("remove_pending_lock_requests_by_mid_smb1 - "
 656                                    "removing request type %d for file %s fnum "
 657                                    "= %d\n", blr->req->cmd, fsp_str_dbg(fsp),
 658                                    fsp->fnum ));
 659
 660                         brl_lock_cancel(br_lck,
 661                                         blr->smblctx,
 662                                         sconn_server_id(sconn),
 663                                         blr->offset,
 664                                         blr->count,
 665                                         blr->lock_flav,
 666                                         blr);
 667                         TALLOC_FREE(br_lck);
 668                 }
 669
 670                 blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 671                 DLIST_REMOVE(sconn->smb1.locks.blocking_lock_queue, blr);
 672                 TALLOC_FREE(blr);
 673         }
 674 }
 675
 676 /****************************************************************************
 677  Is this mid a blocking lock request on the queue ?
 678  Currently only called from the SMB1 unix extensions POSIX lock code.
 679 *****************************************************************************/
 680
 681 bool blocking_lock_was_deferred_smb1(
 682         struct smbd_server_connection *sconn, uint64_t mid)
 683 {
 684         struct blocking_lock_record *blr, *next = NULL;
 685
 686         for(blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = next) {
 687                 next = blr->next;
 688                 if(blr->req->mid == mid) {
 689                         return True;
 690                 }
 691         }
 692         return False;
 693 }
 694
 695 /****************************************************************************
 696   Set a flag as an unlock request affects one of our pending locks.
 697 *****************************************************************************/
 698
 699 static void received_unlock_msg(struct messaging_context *msg,
 700                                 void *private_data,
 701                                 uint32_t msg_type,
 702                                 struct server_id server_id,
 703                                 DATA_BLOB *data)
 704 {
 705         struct smbd_server_connection *sconn =
 706                 talloc_get_type_abort(private_data,
 707                 struct smbd_server_connection);
 708
 709         DEBUG(10,("received_unlock_msg\n"));
 710         process_blocking_lock_queue(sconn);
 711 }
 712
 713 /****************************************************************************
 714  Process the blocking lock queue. Note that this is only called as root.
 715 *****************************************************************************/
 716
 717 void process_blocking_lock_queue(struct smbd_server_connection *sconn)
 718 {
 719         struct timeval tv_curr = timeval_current();
 720         struct blocking_lock_record *blr, *next = NULL;
 721
 722         if (sconn->using_smb2) {
 723                 process_blocking_lock_queue_smb2(sconn, tv_curr);
 724                 return;
 725         }
 726
 727         /*
 728          * Go through the queue and see if we can get any of the locks.
 729          */
 730
 731         for (blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = next) {
 732
 733                 next = blr->next;
 734
 735                 /*
 736                  * Go through the remaining locks and try and obtain them.
 737                  * The call returns True if all locks were obtained successfully
 738                  * and False if we still need to wait.
 739                  */
 740
 741                 DEBUG(10, ("Processing BLR = %p\n", blr));
 742
 743                 /* We use set_current_service so connections with
 744                  * pending locks are not marked as idle.
 745                  */
 746
 747                 set_current_service(blr->fsp->conn,
 748                                 SVAL(blr->req->inbuf,smb_flg),
 749                                 false);
 750
 751                 if(blocking_lock_record_process(blr)) {
 752                         struct byte_range_lock *br_lck = brl_get_locks(
 753                                 talloc_tos(), blr->fsp);
 754
 755                         DEBUG(10, ("BLR_process returned true: cancelling and "
 756                             "removing lock. BLR = %p\n", blr));
 757
 758                         if (br_lck) {
 759                                 brl_lock_cancel(br_lck,
 760                                         blr->smblctx,
 761                                         sconn_server_id(sconn),
 762                                         blr->offset,
 763                                         blr->count,
 764                                         blr->lock_flav,
 765                                         blr);
 766                                 TALLOC_FREE(br_lck);
 767                         }
 768
 769                         DLIST_REMOVE(sconn->smb1.locks.blocking_lock_queue, blr);
 770                         TALLOC_FREE(blr);
 771                         continue;
 772                 }
 773
 774                 /*
 775                  * We couldn't get the locks for this record on the list.
 776                  * If the time has expired, return a lock error.
 777                  */
 778
 779                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 780                         struct byte_range_lock *br_lck = brl_get_locks(
 781                                 talloc_tos(), blr->fsp);
 782
 783                         DEBUG(10, ("Lock timed out! BLR = %p\n", blr));
 784
 785                         /*
 786                          * Lock expired - throw away all previously
 787                          * obtained locks and return lock error.
 788                          */
 789
 790                         if (br_lck) {
 791                                 DEBUG(5,("process_blocking_lock_queue: "
 792                                          "pending lock fnum = %d for file %s "
 793                                          "timed out.\n", blr->fsp->fnum,
 794                                          fsp_str_dbg(blr->fsp)));
 795
 796                                 brl_lock_cancel(br_lck,
 797                                         blr->smblctx,
 798                                         sconn_server_id(sconn),
 799                                         blr->offset,
 800                                         blr->count,
 801                                         blr->lock_flav,
 802                                         blr);
 803                                 TALLOC_FREE(br_lck);
 804                         }
 805
 806                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 807                         DLIST_REMOVE(sconn->smb1.locks.blocking_lock_queue, blr);
 808                         TALLOC_FREE(blr);
 809                 }
 810         }
 811
 812         recalc_brl_timeout(sconn);
 813 }
 814
 815 /****************************************************************************
 816  Handle a cancel message. Lock already moved onto the cancel queue.
 817 *****************************************************************************/
 818
 819 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(struct blocking_lock_record *) + sizeof(NTSTATUS))
 820
 821 static void process_blocking_lock_cancel_message(struct messaging_context *ctx,
 822                                                  void *private_data,
 823                                                  uint32_t msg_type,
 824                                                  struct server_id server_id,
 825                                                  DATA_BLOB *data)
 826 {
 827         NTSTATUS err;
 828         const char *msg = (const char *)data->data;
 829         struct blocking_lock_record *blr;
 830         struct smbd_server_connection *sconn =
 831                 talloc_get_type_abort(private_data,
 832                 struct smbd_server_connection);
 833
 834         if (data->data == NULL) {
 835                 smb_panic("process_blocking_lock_cancel_message: null msg");
 836         }
 837
 838         if (data->length != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 839                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 840                           "Got invalid msg len %d\n", (int)data->length));
 841                 smb_panic("process_blocking_lock_cancel_message: bad msg");
 842         }
 843
 844         memcpy(&blr, msg, sizeof(blr));
 845         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 846
 847         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 848                 nt_errstr(err) ));
 849
 850         blocking_lock_reply_error(blr, err);
 851         DLIST_REMOVE(sconn->smb1.locks.blocking_lock_cancelled_queue, blr);
 852         TALLOC_FREE(blr);
 853 }
 854
 855 /****************************************************************************
 856  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 857  Returns the blocking_lock_record that is being cancelled.
 858  Only called from the SMB1 code.
 859 *****************************************************************************/
 860
 861 struct blocking_lock_record *blocking_lock_cancel_smb1(files_struct *fsp,
 862                         uint64_t smblctx,
 863                         uint64_t offset,
 864                         uint64_t count,
 865                         enum brl_flavour lock_flav,
 866                         unsigned char locktype,
 867                         NTSTATUS err)
 868 {
 869         struct smbd_server_connection *sconn = fsp->conn->sconn;
 870         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 871         struct blocking_lock_record *blr;
 872
 873         if (!sconn->smb1.locks.blocking_lock_cancel_state) {
 874                 /* Register our message. */
 875                 messaging_register(sconn->msg_ctx, sconn,
 876                                    MSG_SMB_BLOCKING_LOCK_CANCEL,
 877                                    process_blocking_lock_cancel_message);
 878
 879                 sconn->smb1.locks.blocking_lock_cancel_state = True;
 880         }
 881
 882         for (blr = sconn->smb1.locks.blocking_lock_queue; blr; blr = blr->next) {
 883                 if (fsp == blr->fsp &&
 884                                 smblctx == blr->smblctx &&
 885                                 offset == blr->offset &&
 886                                 count == blr->count &&
 887                                 lock_flav == blr->lock_flav) {
 888                         break;
 889                 }
 890         }
 891
 892         if (!blr) {
 893                 return NULL;
 894         }
 895
 896         /* Check the flags are right. */
 897         if (blr->req->cmd == SMBlockingX &&
 898                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 899                         (CVAL(blr->req->vwv+3, 0) & LOCKING_ANDX_LARGE_FILES)) {
 900                 return NULL;
 901         }
 902
 903         /* Move to cancelled queue. */
 904         DLIST_REMOVE(sconn->smb1.locks.blocking_lock_queue, blr);
 905         DLIST_ADD(sconn->smb1.locks.blocking_lock_cancelled_queue, blr);
 906
 907         /* Create the message. */
 908         memcpy(msg, &blr, sizeof(blr));
 909         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 910
 911         messaging_send_buf(sconn->msg_ctx, sconn_server_id(sconn),
 912                            MSG_SMB_BLOCKING_LOCK_CANCEL,
 913                            (uint8 *)&msg, sizeof(msg));
 914
 915         return blr;
 916 }