source/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 2 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, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22 #undef DBGC_CLASS
  23 #define DBGC_CLASS DBGC_LOCKING
  24
  25 extern int max_send;
  26
  27 /****************************************************************************
  28  This is the structure to queue to implement blocking locks.
  29  notify. It consists of the requesting SMB and the expiry time.
  30 *****************************************************************************/
  31
  32 typedef struct _blocking_lock_record {
  33         struct _blocking_lock_record *next;
  34         struct _blocking_lock_record *prev;
  35         int com_type;
  36         files_struct *fsp;
  37         struct timeval expire_time;
  38         int lock_num;
  39         SMB_BIG_UINT offset;
  40         SMB_BIG_UINT count;
  41         uint32 lock_pid;
  42         enum brl_flavour lock_flav;
  43         enum brl_type lock_type;
  44         char *inbuf;
  45         int length;
  46 } blocking_lock_record;
  47
  48 /* dlink list we store pending lock records on. */
  49 static blocking_lock_record *blocking_lock_queue;
  50
  51 /* dlink list we move cancelled lock records onto. */
  52 static blocking_lock_record *blocking_lock_cancelled_queue;
  53
  54 /* The event that makes us process our blocking lock queue */
  55 static struct timed_event *brl_timeout;
  56
  57 /****************************************************************************
  58  Destructor for the above structure.
  59 ****************************************************************************/
  60
  61 static void free_blocking_lock_record(blocking_lock_record *blr)
  62 {
  63         SAFE_FREE(blr->inbuf);
  64         SAFE_FREE(blr);
  65 }
  66
  67 /****************************************************************************
  68  Determine if this is a secondary element of a chained SMB.
  69   **************************************************************************/
  70
  71 static BOOL in_chained_smb(void)
  72 {
  73         return (chain_size != 0);
  74 }
  75
  76 static void received_unlock_msg(int msg_type, struct server_id src,
  77                                 void *buf, size_t len,
  78                                 void *private_data);
  79 static void process_blocking_lock_queue(void);
  80
  81 static void brl_timeout_fn(struct event_context *event_ctx,
  82                            struct timed_event *te,
  83                            const struct timeval *now,
  84                            void *private_data)
  85 {
  86         SMB_ASSERT(brl_timeout == te);
  87         TALLOC_FREE(brl_timeout);
  88
  89         change_to_root_user();  /* TODO: Possibly run all timed events as
  90                                  * root */
  91
  92         process_blocking_lock_queue();
  93 }
  94
  95 /****************************************************************************
  96  After a change to blocking_lock_queue, recalculate the timed_event for the
  97  next processing.
  98 ****************************************************************************/
  99
 100 static BOOL recalc_brl_timeout(void)
 101 {
 102         blocking_lock_record *brl;
 103         struct timeval next_timeout;
 104
 105         TALLOC_FREE(brl_timeout);
 106
 107         next_timeout = timeval_zero();
 108
 109         for (brl = blocking_lock_queue; brl; brl = brl->next) {
 110                 if (timeval_is_zero(&brl->expire_time)) {
 111                         continue;
 112                 }
 113
 114                 if (timeval_is_zero(&next_timeout)) {
 115                         next_timeout = brl->expire_time;
 116                 }
 117                 else {
 118                         next_timeout = timeval_min(&next_timeout,
 119                                                    &brl->expire_time);
 120                 }
 121         }
 122
 123         if (timeval_is_zero(&next_timeout)) {
 124                 return True;
 125         }
 126
 127         if (!(brl_timeout = event_add_timed(smbd_event_context(), NULL,
 128                                             next_timeout, "brl_timeout",
 129                                             brl_timeout_fn, NULL))) {
 130                 return False;
 131         }
 132
 133         return True;
 134 }
 135
 136
 137 /****************************************************************************
 138  Function to push a blocking lock request onto the lock queue.
 139 ****************************************************************************/
 140
 141 BOOL push_blocking_lock_request( struct byte_range_lock *br_lck,
 142                 char *inbuf, int length,
 143                 files_struct *fsp,
 144                 int lock_timeout,
 145                 int lock_num,
 146                 uint32 lock_pid,
 147                 enum brl_type lock_type,
 148                 enum brl_flavour lock_flav,
 149                 SMB_BIG_UINT offset, SMB_BIG_UINT count)
 150 {
 151         static BOOL set_lock_msg;
 152         blocking_lock_record *blr;
 153         NTSTATUS status;
 154
 155         if(in_chained_smb() ) {
 156                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 157                 return False;
 158         }
 159
 160         /*
 161          * Now queue an entry on the blocking lock queue. We setup
 162          * the expiration time here.
 163          */
 164
 165         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 166                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 167                 return False;
 168         }
 169
 170         blr->next = NULL;
 171         blr->prev = NULL;
 172
 173         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 174                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 175                 SAFE_FREE(blr);
 176                 return False;
 177         }
 178
 179         blr->com_type = CVAL(inbuf,smb_com);
 180         blr->fsp = fsp;
 181         if (lock_timeout == -1) {
 182                 blr->expire_time.tv_sec = 0;
 183                 blr->expire_time.tv_usec = 0; /* Never expire. */
 184         } else {
 185                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 186                                         (lock_timeout % 1000) * 1000);
 187         }
 188         blr->lock_num = lock_num;
 189         blr->lock_pid = lock_pid;
 190         blr->lock_flav = lock_flav;
 191         blr->lock_type = lock_type;
 192         blr->offset = offset;
 193         blr->count = count;
 194         memcpy(blr->inbuf, inbuf, length);
 195         blr->length = length;
 196
 197         /* Add a pending lock record for this. */
 198         status = brl_lock(br_lck,
 199                         lock_pid,
 200                         procid_self(),
 201                         offset,
 202                         count,
 203                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 204                         blr->lock_flav,
 205                         lock_timeout ? True : False); /* blocking_lock. */
 206
 207         if (!NT_STATUS_IS_OK(status)) {
 208                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 209                 DLIST_REMOVE(blocking_lock_queue, blr);
 210                 free_blocking_lock_record(blr);
 211                 return False;
 212         }
 213
 214         DLIST_ADD_END(blocking_lock_queue, blr, blocking_lock_record *);
 215         recalc_brl_timeout();
 216
 217         /* Ensure we'll receive messages when this is unlocked. */
 218         if (!set_lock_msg) {
 219                 message_register(MSG_SMB_UNLOCK, received_unlock_msg,
 220                                  NULL);
 221                 set_lock_msg = True;
 222         }
 223
 224         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
 225                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 226                 length, (unsigned int)blr->expire_time.tv_sec,
 227                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 228                 blr->fsp->fnum, blr->fsp->fsp_name ));
 229
 230         /* Push the MID of this packet on the signing queue. */
 231         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 232
 233         return True;
 234 }
 235
 236 /****************************************************************************
 237  Return a smd with a given size.
 238 *****************************************************************************/
 239
 240 static void send_blocking_reply(char *outbuf, int outsize, const char *inbuf)
 241 {
 242         if(outsize > 4) {
 243                 smb_setlen(inbuf, outbuf,outsize - 4);
 244         }
 245
 246         if (!send_smb(smbd_server_fd(),outbuf)) {
 247                 exit_server_cleanly("send_blocking_reply: send_smb failed.");
 248         }
 249 }
 250
 251 /****************************************************************************
 252  Return a lockingX success SMB.
 253 *****************************************************************************/
 254
 255 static void reply_lockingX_success(blocking_lock_record *blr)
 256 {
 257         char *outbuf = get_OutBuffer();
 258         int bufsize = BUFFER_SIZE;
 259         char *inbuf = blr->inbuf;
 260         int outsize = 0;
 261
 262         construct_reply_common(inbuf, outbuf);
 263         set_message(inbuf,outbuf,2,0,True);
 264
 265         /*
 266          * As this message is a lockingX call we must handle
 267          * any following chained message correctly.
 268          * This is normally handled in construct_reply(),
 269          * but as that calls switch_message, we can't use
 270          * that here and must set up the chain info manually.
 271          */
 272
 273         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 274
 275         outsize += chain_size;
 276
 277         send_blocking_reply(outbuf,outsize,inbuf);
 278 }
 279
 280 /****************************************************************************
 281  Return a generic lock fail error blocking call.
 282 *****************************************************************************/
 283
 284 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 285 {
 286         char *outbuf = get_OutBuffer();
 287         char *inbuf = blr->inbuf;
 288         construct_reply_common(inbuf, outbuf);
 289
 290         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 291            FILE_LOCK_CONFLICT! (tridge) */
 292         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 293                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 294         }
 295
 296         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 297                 /* Store the last lock error. */
 298                 files_struct *fsp = blr->fsp;
 299
 300                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 301                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 302                 fsp->last_lock_failure.context.pid = procid_self();
 303                 fsp->last_lock_failure.start = blr->offset;
 304                 fsp->last_lock_failure.size = blr->count;
 305                 fsp->last_lock_failure.fnum = fsp->fnum;
 306                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 307                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 308         }
 309
 310         ERROR_NT(status);
 311         if (!send_smb(smbd_server_fd(),outbuf)) {
 312                 exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
 313         }
 314 }
 315
 316 /****************************************************************************
 317  Return a lock fail error for a lockingX call. Undo all the locks we have
 318  obtained first.
 319 *****************************************************************************/
 320
 321 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 322 {
 323         char *inbuf = blr->inbuf;
 324         files_struct *fsp = blr->fsp;
 325         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 326         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 327         uint32 lock_pid;
 328         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 329         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 330         char *data;
 331         int i;
 332
 333         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 334
 335         /*
 336          * Data now points at the beginning of the list
 337          * of smb_lkrng structs.
 338          */
 339
 340         /*
 341          * Ensure we don't do a remove on the lock that just failed,
 342          * as under POSIX rules, if we have a lock already there, we
 343          * will delete it (and we shouldn't) .....
 344          */
 345
 346         for(i = blr->lock_num - 1; i >= 0; i--) {
 347                 BOOL err;
 348
 349                 lock_pid = get_lock_pid( data, i, large_file_format);
 350                 count = get_lock_count( data, i, large_file_format);
 351                 offset = get_lock_offset( data, i, large_file_format, &err);
 352
 353                 /*
 354                  * We know err cannot be set as if it was the lock
 355                  * request would never have been queued. JRA.
 356                  */
 357
 358                 do_unlock(fsp,
 359                         lock_pid,
 360                         count,
 361                         offset,
 362                         WINDOWS_LOCK);
 363         }
 364
 365         generic_blocking_lock_error(blr, status);
 366 }
 367
 368 /****************************************************************************
 369  Return a lock fail error.
 370 *****************************************************************************/
 371
 372 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 373 {
 374         switch(blr->com_type) {
 375         case SMBlockingX:
 376                 reply_lockingX_error(blr, status);
 377                 break;
 378         case SMBtrans2:
 379         case SMBtranss2:
 380                 {
 381                         char *outbuf = get_OutBuffer();
 382                         char *inbuf = blr->inbuf;
 383                         construct_reply_common(inbuf, outbuf);
 384                         /* construct_reply_common has done us the favor to pre-fill the
 385                          * command field with SMBtranss2 which is wrong :-)
 386                          */
 387                         SCVAL(outbuf,smb_com,SMBtrans2);
 388                         ERROR_NT(status);
 389                         if (!send_smb(smbd_server_fd(),outbuf)) {
 390                                 exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
 391                         }
 392                         break;
 393                 }
 394         default:
 395                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 396                 exit_server("PANIC - unknown type on blocking lock queue");
 397         }
 398 }
 399
 400 /****************************************************************************
 401  Attempt to finish off getting all pending blocking locks for a lockingX call.
 402  Returns True if we want to be removed from the list.
 403 *****************************************************************************/
 404
 405 static BOOL process_lockingX(blocking_lock_record *blr)
 406 {
 407         char *inbuf = blr->inbuf;
 408         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 409         files_struct *fsp = blr->fsp;
 410         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 411         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 412         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 413         uint32 lock_pid;
 414         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 415         char *data;
 416         NTSTATUS status = NT_STATUS_OK;
 417
 418         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 419
 420         /*
 421          * Data now points at the beginning of the list
 422          * of smb_lkrng structs.
 423          */
 424
 425         for(; blr->lock_num < num_locks; blr->lock_num++) {
 426                 struct byte_range_lock *br_lck = NULL;
 427                 BOOL err;
 428
 429                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 430                 count = get_lock_count( data, blr->lock_num, large_file_format);
 431                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 432
 433                 /*
 434                  * We know err cannot be set as if it was the lock
 435                  * request would never have been queued. JRA.
 436                  */
 437                 errno = 0;
 438                 br_lck = do_lock(fsp,
 439                                 lock_pid,
 440                                 count,
 441                                 offset,
 442                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 443                                         READ_LOCK : WRITE_LOCK),
 444                                 WINDOWS_LOCK,
 445                                 True,
 446                                 &status);
 447
 448                 TALLOC_FREE(br_lck);
 449
 450                 if (NT_STATUS_IS_ERR(status)) {
 451                         break;
 452                 }
 453         }
 454
 455         if(blr->lock_num == num_locks) {
 456                 /*
 457                  * Success - we got all the locks.
 458                  */
 459
 460                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 461                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 462
 463                 reply_lockingX_success(blr);
 464                 return True;
 465         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 466                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 467                         /*
 468                          * We have other than a "can't get lock"
 469                          * error. Free any locks we had and return an error.
 470                          * Return True so we get dequeued.
 471                          */
 472
 473                 blocking_lock_reply_error(blr, status);
 474                 return True;
 475         }
 476
 477         /*
 478          * Still can't get all the locks - keep waiting.
 479          */
 480
 481         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 482 Waiting....\n",
 483                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 484
 485         return False;
 486 }
 487
 488 /****************************************************************************
 489  Attempt to get the posix lock request from a SMBtrans2 call.
 490  Returns True if we want to be removed from the list.
 491 *****************************************************************************/
 492
 493 static BOOL process_trans2(blocking_lock_record *blr)
 494 {
 495         char *inbuf = blr->inbuf;
 496         char *outbuf;
 497         char params[2];
 498         NTSTATUS status;
 499         struct byte_range_lock *br_lck = do_lock(blr->fsp,
 500                                                 blr->lock_pid,
 501                                                 blr->count,
 502                                                 blr->offset,
 503                                                 blr->lock_type,
 504                                                 blr->lock_flav,
 505                                                 True,
 506                                                 &status);
 507         TALLOC_FREE(br_lck);
 508
 509         if (!NT_STATUS_IS_OK(status)) {
 510                 if (ERROR_WAS_LOCK_DENIED(status)) {
 511                         /* Still can't get the lock, just keep waiting. */
 512                         return False;
 513                 }
 514                 /*
 515                  * We have other than a "can't get lock"
 516                  * error. Send an error and return True so we get dequeued.
 517                  */
 518                 blocking_lock_reply_error(blr, status);
 519                 return True;
 520         }
 521
 522         /* We finally got the lock, return success. */
 523         outbuf = get_OutBuffer();
 524         construct_reply_common(inbuf, outbuf);
 525         SCVAL(outbuf,smb_com,SMBtrans2);
 526         SSVAL(params,0,0);
 527         /* Fake up max_data_bytes here - we know it fits. */
 528         send_trans2_replies(inbuf, outbuf, max_send, params, 2, NULL, 0, 0xffff);
 529         return True;
 530 }
 531
 532
 533 /****************************************************************************
 534  Process a blocking lock SMB.
 535  Returns True if we want to be removed from the list.
 536 *****************************************************************************/
 537
 538 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 539 {
 540         switch(blr->com_type) {
 541                 case SMBlockingX:
 542                         return process_lockingX(blr);
 543                 case SMBtrans2:
 544                 case SMBtranss2:
 545                         return process_trans2(blr);
 546                 default:
 547                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 548                         exit_server("PANIC - unknown type on blocking lock queue");
 549         }
 550         return False; /* Keep compiler happy. */
 551 }
 552
 553 /****************************************************************************
 554  Cancel entries by fnum from the blocking lock pending queue.
 555 *****************************************************************************/
 556
 557 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 558 {
 559         blocking_lock_record *blr, *next = NULL;
 560
 561         for(blr = blocking_lock_queue; blr; blr = next) {
 562                 next = blr->next;
 563                 if(blr->fsp->fnum == fsp->fnum) {
 564                         unsigned char locktype = 0;
 565
 566                         if (blr->com_type == SMBlockingX) {
 567                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 568                         }
 569
 570                         if (br_lck) {
 571                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 572 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 573
 574                                 brl_lock_cancel(br_lck,
 575                                         blr->lock_pid,
 576                                         procid_self(),
 577                                         blr->offset,
 578                                         blr->count,
 579                                         blr->lock_flav);
 580
 581                                 blocking_lock_cancel(fsp,
 582                                         blr->lock_pid,
 583                                         blr->offset,
 584                                         blr->count,
 585                                         blr->lock_flav,
 586                                         locktype,
 587                                         NT_STATUS_RANGE_NOT_LOCKED);
 588                         }
 589                 }
 590         }
 591 }
 592
 593 /****************************************************************************
 594  Delete entries by mid from the blocking lock pending queue. Always send reply.
 595 *****************************************************************************/
 596
 597 void remove_pending_lock_requests_by_mid(int mid)
 598 {
 599         blocking_lock_record *blr, *next = NULL;
 600
 601         for(blr = blocking_lock_queue; blr; blr = next) {
 602                 next = blr->next;
 603                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 604                         files_struct *fsp = blr->fsp;
 605                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 606
 607                         if (br_lck) {
 608                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 609 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 610
 611                                 brl_lock_cancel(br_lck,
 612                                         blr->lock_pid,
 613                                         procid_self(),
 614                                         blr->offset,
 615                                         blr->count,
 616                                         blr->lock_flav);
 617                                 TALLOC_FREE(br_lck);
 618                         }
 619
 620                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 621                         DLIST_REMOVE(blocking_lock_queue, blr);
 622                         free_blocking_lock_record(blr);
 623                 }
 624         }
 625 }
 626
 627 /****************************************************************************
 628  Is this mid a blocking lock request on the queue ?
 629 *****************************************************************************/
 630
 631 BOOL blocking_lock_was_deferred(int mid)
 632 {
 633         blocking_lock_record *blr, *next = NULL;
 634
 635         for(blr = blocking_lock_queue; blr; blr = next) {
 636                 next = blr->next;
 637                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 638                         return True;
 639                 }
 640         }
 641         return False;
 642 }
 643
 644 /****************************************************************************
 645   Set a flag as an unlock request affects one of our pending locks.
 646 *****************************************************************************/
 647
 648 static void received_unlock_msg(int msg_type, struct server_id src,
 649                                 void *buf, size_t len,
 650                                 void *private_data)
 651 {
 652         DEBUG(10,("received_unlock_msg\n"));
 653         process_blocking_lock_queue();
 654 }
 655
 656 /****************************************************************************
 657  Process the blocking lock queue. Note that this is only called as root.
 658 *****************************************************************************/
 659
 660 static void process_blocking_lock_queue(void)
 661 {
 662         struct timeval tv_curr = timeval_current();
 663         blocking_lock_record *blr, *next = NULL;
 664         BOOL recalc_timeout = False;
 665
 666         /*
 667          * Go through the queue and see if we can get any of the locks.
 668          */
 669
 670         for (blr = blocking_lock_queue; blr; blr = next) {
 671                 connection_struct *conn = NULL;
 672                 uint16 vuid;
 673                 files_struct *fsp = NULL;
 674
 675                 next = blr->next;
 676
 677                 /*
 678                  * Ensure we don't have any old chain_fsp values
 679                  * sitting around....
 680                  */
 681                 chain_size = 0;
 682                 file_chain_reset();
 683                 fsp = blr->fsp;
 684
 685                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 686                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 687                                 SVAL(blr->inbuf,smb_uid);
 688
 689                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 690                         fsp->fnum, fsp->fsp_name ));
 691
 692                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 693                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 694
 695                         /*
 696                          * Lock expired - throw away all previously
 697                          * obtained locks and return lock error.
 698                          */
 699
 700                         if (br_lck) {
 701                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 702                                         fsp->fnum, fsp->fsp_name ));
 703
 704                                 brl_lock_cancel(br_lck,
 705                                         blr->lock_pid,
 706                                         procid_self(),
 707                                         blr->offset,
 708                                         blr->count,
 709                                         blr->lock_flav);
 710                                 TALLOC_FREE(br_lck);
 711                         }
 712
 713                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 714                         DLIST_REMOVE(blocking_lock_queue, blr);
 715                         free_blocking_lock_record(blr);
 716                         recalc_timeout = True;
 717                         continue;
 718                 }
 719
 720                 if(!change_to_user(conn,vuid)) {
 721                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 722
 723                         /*
 724                          * Remove the entry and return an error to the client.
 725                          */
 726
 727                         if (br_lck) {
 728                                 brl_lock_cancel(br_lck,
 729                                         blr->lock_pid,
 730                                         procid_self(),
 731                                         blr->offset,
 732                                         blr->count,
 733                                         blr->lock_flav);
 734                                 TALLOC_FREE(br_lck);
 735                         }
 736
 737                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 738                                 vuid ));
 739                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 740                         DLIST_REMOVE(blocking_lock_queue, blr);
 741                         free_blocking_lock_record(blr);
 742                         recalc_timeout = True;
 743                         continue;
 744                 }
 745
 746                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 747                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 748
 749                         /*
 750                          * Remove the entry and return an error to the client.
 751                          */
 752
 753                         if (br_lck) {
 754                                 brl_lock_cancel(br_lck,
 755                                         blr->lock_pid,
 756                                         procid_self(),
 757                                         blr->offset,
 758                                         blr->count,
 759                                         blr->lock_flav);
 760                                 TALLOC_FREE(br_lck);
 761                         }
 762
 763                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 764                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 765                         DLIST_REMOVE(blocking_lock_queue, blr);
 766                         free_blocking_lock_record(blr);
 767                         recalc_timeout = True;
 768                         change_to_root_user();
 769                         continue;
 770                 }
 771
 772                 /*
 773                  * Go through the remaining locks and try and obtain them.
 774                  * The call returns True if all locks were obtained successfully
 775                  * and False if we still need to wait.
 776                  */
 777
 778                 if(blocking_lock_record_process(blr)) {
 779                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 780
 781                         if (br_lck) {
 782                                 brl_lock_cancel(br_lck,
 783                                         blr->lock_pid,
 784                                         procid_self(),
 785                                         blr->offset,
 786                                         blr->count,
 787                                         blr->lock_flav);
 788                                 TALLOC_FREE(br_lck);
 789                         }
 790
 791                         DLIST_REMOVE(blocking_lock_queue, blr);
 792                         free_blocking_lock_record(blr);
 793                         recalc_timeout = True;
 794                 }
 795                 change_to_root_user();
 796         }
 797
 798         if (recalc_timeout) {
 799                 recalc_brl_timeout();
 800         }
 801 }
 802
 803 /****************************************************************************
 804  Handle a cancel message. Lock already moved onto the cancel queue.
 805 *****************************************************************************/
 806
 807 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 808
 809 static void process_blocking_lock_cancel_message(int msg_type,
 810                                                  struct server_id src,
 811                                                  void *buf, size_t len,
 812                                                  void *private_data)
 813 {
 814         NTSTATUS err;
 815         const char *msg = (const char *)buf;
 816         blocking_lock_record *blr;
 817
 818         if (buf == NULL) {
 819                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 820         }
 821
 822         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 823                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 824                         "Got invalid msg len %d\n", (int)len));
 825                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 826         }
 827
 828         memcpy(&blr, msg, sizeof(blr));
 829         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 830
 831         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 832                 nt_errstr(err) ));
 833
 834         blocking_lock_reply_error(blr, err);
 835         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 836         free_blocking_lock_record(blr);
 837 }
 838
 839 /****************************************************************************
 840  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 841 *****************************************************************************/
 842
 843 BOOL blocking_lock_cancel(files_struct *fsp,
 844                         uint32 lock_pid,
 845                         SMB_BIG_UINT offset,
 846                         SMB_BIG_UINT count,
 847                         enum brl_flavour lock_flav,
 848                         unsigned char locktype,
 849                         NTSTATUS err)
 850 {
 851         static BOOL initialized;
 852         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 853         blocking_lock_record *blr;
 854
 855         if (!initialized) {
 856                 /* Register our message. */
 857                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 858                                  process_blocking_lock_cancel_message,
 859                                  NULL);
 860
 861                 initialized = True;
 862         }
 863
 864         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 865                 if (fsp == blr->fsp &&
 866                                 lock_pid == blr->lock_pid &&
 867                                 offset == blr->offset &&
 868                                 count == blr->count &&
 869                                 lock_flav == blr->lock_flav) {
 870                         break;
 871                 }
 872         }
 873
 874         if (!blr) {
 875                 return False;
 876         }
 877
 878         /* Check the flags are right. */
 879         if (blr->com_type == SMBlockingX &&
 880                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 881                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 882                 return False;
 883         }
 884
 885         /* Move to cancelled queue. */
 886         DLIST_REMOVE(blocking_lock_queue, blr);
 887         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 888
 889         /* Create the message. */
 890         memcpy(msg, &blr, sizeof(blr));
 891         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 892
 893         message_send_pid(pid_to_procid(sys_getpid()),
 894                         MSG_SMB_BLOCKING_LOCK_CANCEL,
 895                         &msg, sizeof(msg), True);
 896
 897         return True;
 898 }