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 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 process_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)
 241 {
 242         if(outsize > 4)
 243                 smb_setlen(outbuf,outsize - 4);
 244
 245         if (!send_smb(smbd_server_fd(),outbuf))
 246                 exit_server_cleanly("send_blocking_reply: send_smb failed.");
 247 }
 248
 249 /****************************************************************************
 250  Return a lockingX success SMB.
 251 *****************************************************************************/
 252
 253 static void reply_lockingX_success(blocking_lock_record *blr)
 254 {
 255         char *outbuf = get_OutBuffer();
 256         int bufsize = BUFFER_SIZE;
 257         char *inbuf = blr->inbuf;
 258         int outsize = 0;
 259
 260         construct_reply_common(inbuf, outbuf);
 261         set_message(outbuf,2,0,True);
 262
 263         /*
 264          * As this message is a lockingX call we must handle
 265          * any following chained message correctly.
 266          * This is normally handled in construct_reply(),
 267          * but as that calls switch_message, we can't use
 268          * that here and must set up the chain info manually.
 269          */
 270
 271         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 272
 273         outsize += chain_size;
 274
 275         send_blocking_reply(outbuf,outsize);
 276 }
 277
 278 /****************************************************************************
 279  Return a generic lock fail error blocking call.
 280 *****************************************************************************/
 281
 282 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 283 {
 284         char *outbuf = get_OutBuffer();
 285         char *inbuf = blr->inbuf;
 286         construct_reply_common(inbuf, outbuf);
 287
 288         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 289            FILE_LOCK_CONFLICT! (tridge) */
 290         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 291                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 292         }
 293
 294         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 295                 /* Store the last lock error. */
 296                 files_struct *fsp = blr->fsp;
 297
 298                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 299                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 300                 fsp->last_lock_failure.context.pid = procid_self();
 301                 fsp->last_lock_failure.start = blr->offset;
 302                 fsp->last_lock_failure.size = blr->count;
 303                 fsp->last_lock_failure.fnum = fsp->fnum;
 304                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 305                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 306         }
 307
 308         ERROR_NT(status);
 309         if (!send_smb(smbd_server_fd(),outbuf)) {
 310                 exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
 311         }
 312 }
 313
 314 /****************************************************************************
 315  Return a lock fail error for a lockingX call. Undo all the locks we have
 316  obtained first.
 317 *****************************************************************************/
 318
 319 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 320 {
 321         char *inbuf = blr->inbuf;
 322         files_struct *fsp = blr->fsp;
 323         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 324         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 325         uint32 lock_pid;
 326         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 327         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 328         char *data;
 329         int i;
 330
 331         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 332
 333         /*
 334          * Data now points at the beginning of the list
 335          * of smb_lkrng structs.
 336          */
 337
 338         /*
 339          * Ensure we don't do a remove on the lock that just failed,
 340          * as under POSIX rules, if we have a lock already there, we
 341          * will delete it (and we shouldn't) .....
 342          */
 343
 344         for(i = blr->lock_num - 1; i >= 0; i--) {
 345                 BOOL err;
 346
 347                 lock_pid = get_lock_pid( data, i, large_file_format);
 348                 count = get_lock_count( data, i, large_file_format);
 349                 offset = get_lock_offset( data, i, large_file_format, &err);
 350
 351                 /*
 352                  * We know err cannot be set as if it was the lock
 353                  * request would never have been queued. JRA.
 354                  */
 355
 356                 do_unlock(fsp,
 357                         lock_pid,
 358                         count,
 359                         offset,
 360                         WINDOWS_LOCK);
 361         }
 362
 363         generic_blocking_lock_error(blr, status);
 364 }
 365
 366 /****************************************************************************
 367  Return a lock fail error.
 368 *****************************************************************************/
 369
 370 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 371 {
 372         switch(blr->com_type) {
 373         case SMBlockingX:
 374                 reply_lockingX_error(blr, status);
 375                 break;
 376         case SMBtrans2:
 377         case SMBtranss2:
 378                 {
 379                         char *outbuf = get_OutBuffer();
 380                         char *inbuf = blr->inbuf;
 381                         construct_reply_common(inbuf, outbuf);
 382                         /* construct_reply_common has done us the favor to pre-fill the
 383                          * command field with SMBtranss2 which is wrong :-)
 384                          */
 385                         SCVAL(outbuf,smb_com,SMBtrans2);
 386                         ERROR_NT(status);
 387                         if (!send_smb(smbd_server_fd(),outbuf)) {
 388                                 exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
 389                         }
 390                         break;
 391                 }
 392         default:
 393                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 394                 exit_server("PANIC - unknown type on blocking lock queue");
 395         }
 396 }
 397
 398 /****************************************************************************
 399  Attempt to finish off getting all pending blocking locks for a lockingX call.
 400  Returns True if we want to be removed from the list.
 401 *****************************************************************************/
 402
 403 static BOOL process_lockingX(blocking_lock_record *blr)
 404 {
 405         char *inbuf = blr->inbuf;
 406         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 407         files_struct *fsp = blr->fsp;
 408         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 409         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 410         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 411         uint32 lock_pid;
 412         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 413         char *data;
 414         NTSTATUS status = NT_STATUS_OK;
 415
 416         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 417
 418         /*
 419          * Data now points at the beginning of the list
 420          * of smb_lkrng structs.
 421          */
 422
 423         for(; blr->lock_num < num_locks; blr->lock_num++) {
 424                 struct byte_range_lock *br_lck = NULL;
 425                 BOOL err;
 426
 427                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 428                 count = get_lock_count( data, blr->lock_num, large_file_format);
 429                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 430
 431                 /*
 432                  * We know err cannot be set as if it was the lock
 433                  * request would never have been queued. JRA.
 434                  */
 435                 errno = 0;
 436                 br_lck = do_lock(fsp,
 437                                 lock_pid,
 438                                 count,
 439                                 offset,
 440                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 441                                         READ_LOCK : WRITE_LOCK),
 442                                 WINDOWS_LOCK,
 443                                 True,
 444                                 &status);
 445
 446                 TALLOC_FREE(br_lck);
 447
 448                 if (NT_STATUS_IS_ERR(status)) {
 449                         break;
 450                 }
 451         }
 452
 453         if(blr->lock_num == num_locks) {
 454                 /*
 455                  * Success - we got all the locks.
 456                  */
 457
 458                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 459                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 460
 461                 reply_lockingX_success(blr);
 462                 return True;
 463         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 464                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 465                         /*
 466                          * We have other than a "can't get lock"
 467                          * error. Free any locks we had and return an error.
 468                          * Return True so we get dequeued.
 469                          */
 470
 471                 blocking_lock_reply_error(blr, status);
 472                 return True;
 473         }
 474
 475         /*
 476          * Still can't get all the locks - keep waiting.
 477          */
 478
 479         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 480 Waiting....\n",
 481                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 482
 483         return False;
 484 }
 485
 486 /****************************************************************************
 487  Attempt to get the posix lock request from a SMBtrans2 call.
 488  Returns True if we want to be removed from the list.
 489 *****************************************************************************/
 490
 491 static BOOL process_trans2(blocking_lock_record *blr)
 492 {
 493         char *inbuf = blr->inbuf;
 494         char *outbuf;
 495         char params[2];
 496         NTSTATUS status;
 497         struct byte_range_lock *br_lck = do_lock(blr->fsp,
 498                                                 blr->lock_pid,
 499                                                 blr->count,
 500                                                 blr->offset,
 501                                                 blr->lock_type,
 502                                                 blr->lock_flav,
 503                                                 True,
 504                                                 &status);
 505         TALLOC_FREE(br_lck);
 506
 507         if (!NT_STATUS_IS_OK(status)) {
 508                 if (ERROR_WAS_LOCK_DENIED(status)) {
 509                         /* Still can't get the lock, just keep waiting. */
 510                         return False;
 511                 }
 512                 /*
 513                  * We have other than a "can't get lock"
 514                  * error. Send an error and return True so we get dequeued.
 515                  */
 516                 blocking_lock_reply_error(blr, status);
 517                 return True;
 518         }
 519
 520         /* We finally got the lock, return success. */
 521         outbuf = get_OutBuffer();
 522         construct_reply_common(inbuf, outbuf);
 523         SCVAL(outbuf,smb_com,SMBtrans2);
 524         SSVAL(params,0,0);
 525         /* Fake up max_data_bytes here - we know it fits. */
 526         send_trans2_replies(outbuf, max_send, params, 2, NULL, 0, 0xffff);
 527         return True;
 528 }
 529
 530
 531 /****************************************************************************
 532  Process a blocking lock SMB.
 533  Returns True if we want to be removed from the list.
 534 *****************************************************************************/
 535
 536 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 537 {
 538         switch(blr->com_type) {
 539                 case SMBlockingX:
 540                         return process_lockingX(blr);
 541                 case SMBtrans2:
 542                 case SMBtranss2:
 543                         return process_trans2(blr);
 544                 default:
 545                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 546                         exit_server("PANIC - unknown type on blocking lock queue");
 547         }
 548         return False; /* Keep compiler happy. */
 549 }
 550
 551 /****************************************************************************
 552  Cancel entries by fnum from the blocking lock pending queue.
 553 *****************************************************************************/
 554
 555 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 556 {
 557         blocking_lock_record *blr, *next = NULL;
 558
 559         for(blr = blocking_lock_queue; blr; blr = next) {
 560                 next = blr->next;
 561                 if(blr->fsp->fnum == fsp->fnum) {
 562                         unsigned char locktype = 0;
 563
 564                         if (blr->com_type == SMBlockingX) {
 565                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 566                         }
 567
 568                         if (br_lck) {
 569                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 570 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 571
 572                                 brl_lock_cancel(br_lck,
 573                                         blr->lock_pid,
 574                                         procid_self(),
 575                                         blr->offset,
 576                                         blr->count,
 577                                         blr->lock_flav);
 578
 579                                 blocking_lock_cancel(fsp,
 580                                         blr->lock_pid,
 581                                         blr->offset,
 582                                         blr->count,
 583                                         blr->lock_flav,
 584                                         locktype,
 585                                         NT_STATUS_RANGE_NOT_LOCKED);
 586                         }
 587                 }
 588         }
 589 }
 590
 591 /****************************************************************************
 592  Delete entries by mid from the blocking lock pending queue. Always send reply.
 593 *****************************************************************************/
 594
 595 void remove_pending_lock_requests_by_mid(int mid)
 596 {
 597         blocking_lock_record *blr, *next = NULL;
 598
 599         for(blr = blocking_lock_queue; blr; blr = next) {
 600                 next = blr->next;
 601                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 602                         files_struct *fsp = blr->fsp;
 603                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 604
 605                         if (br_lck) {
 606                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 607 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 608
 609                                 brl_lock_cancel(br_lck,
 610                                         blr->lock_pid,
 611                                         procid_self(),
 612                                         blr->offset,
 613                                         blr->count,
 614                                         blr->lock_flav);
 615                                 TALLOC_FREE(br_lck);
 616                         }
 617
 618                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 619                         DLIST_REMOVE(blocking_lock_queue, blr);
 620                         free_blocking_lock_record(blr);
 621                 }
 622         }
 623 }
 624
 625 /****************************************************************************
 626  Is this mid a blocking lock request on the queue ?
 627 *****************************************************************************/
 628
 629 BOOL blocking_lock_was_deferred(int mid)
 630 {
 631         blocking_lock_record *blr, *next = NULL;
 632
 633         for(blr = blocking_lock_queue; blr; blr = next) {
 634                 next = blr->next;
 635                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 636                         return True;
 637                 }
 638         }
 639         return False;
 640 }
 641
 642 /****************************************************************************
 643   Set a flag as an unlock request affects one of our pending locks.
 644 *****************************************************************************/
 645
 646 static void received_unlock_msg(int msg_type, struct process_id src,
 647                                 void *buf, size_t len,
 648                                 void *private_data)
 649 {
 650         DEBUG(10,("received_unlock_msg\n"));
 651         process_blocking_lock_queue();
 652 }
 653
 654 /****************************************************************************
 655  Process the blocking lock queue. Note that this is only called as root.
 656 *****************************************************************************/
 657
 658 static void process_blocking_lock_queue(void)
 659 {
 660         struct timeval tv_curr = timeval_current();
 661         blocking_lock_record *blr, *next = NULL;
 662         BOOL recalc_timeout = False;
 663
 664         /*
 665          * Go through the queue and see if we can get any of the locks.
 666          */
 667
 668         for (blr = blocking_lock_queue; blr; blr = next) {
 669                 connection_struct *conn = NULL;
 670                 uint16 vuid;
 671                 files_struct *fsp = NULL;
 672
 673                 next = blr->next;
 674
 675                 /*
 676                  * Ensure we don't have any old chain_fsp values
 677                  * sitting around....
 678                  */
 679                 chain_size = 0;
 680                 file_chain_reset();
 681                 fsp = blr->fsp;
 682
 683                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 684                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 685                                 SVAL(blr->inbuf,smb_uid);
 686
 687                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 688                         fsp->fnum, fsp->fsp_name ));
 689
 690                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 691                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 692
 693                         /*
 694                          * Lock expired - throw away all previously
 695                          * obtained locks and return lock error.
 696                          */
 697
 698                         if (br_lck) {
 699                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 700                                         fsp->fnum, fsp->fsp_name ));
 701
 702                                 brl_lock_cancel(br_lck,
 703                                         blr->lock_pid,
 704                                         procid_self(),
 705                                         blr->offset,
 706                                         blr->count,
 707                                         blr->lock_flav);
 708                                 TALLOC_FREE(br_lck);
 709                         }
 710
 711                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 712                         DLIST_REMOVE(blocking_lock_queue, blr);
 713                         free_blocking_lock_record(blr);
 714                         recalc_timeout = True;
 715                         continue;
 716                 }
 717
 718                 if(!change_to_user(conn,vuid)) {
 719                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 720
 721                         /*
 722                          * Remove the entry and return an error to the client.
 723                          */
 724
 725                         if (br_lck) {
 726                                 brl_lock_cancel(br_lck,
 727                                         blr->lock_pid,
 728                                         procid_self(),
 729                                         blr->offset,
 730                                         blr->count,
 731                                         blr->lock_flav);
 732                                 TALLOC_FREE(br_lck);
 733                         }
 734
 735                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 736                                 vuid ));
 737                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 738                         DLIST_REMOVE(blocking_lock_queue, blr);
 739                         free_blocking_lock_record(blr);
 740                         recalc_timeout = True;
 741                         continue;
 742                 }
 743
 744                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 745                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 746
 747                         /*
 748                          * Remove the entry and return an error to the client.
 749                          */
 750
 751                         if (br_lck) {
 752                                 brl_lock_cancel(br_lck,
 753                                         blr->lock_pid,
 754                                         procid_self(),
 755                                         blr->offset,
 756                                         blr->count,
 757                                         blr->lock_flav);
 758                                 TALLOC_FREE(br_lck);
 759                         }
 760
 761                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 762                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 763                         DLIST_REMOVE(blocking_lock_queue, blr);
 764                         free_blocking_lock_record(blr);
 765                         recalc_timeout = True;
 766                         change_to_root_user();
 767                         continue;
 768                 }
 769
 770                 /*
 771                  * Go through the remaining locks and try and obtain them.
 772                  * The call returns True if all locks were obtained successfully
 773                  * and False if we still need to wait.
 774                  */
 775
 776                 if(blocking_lock_record_process(blr)) {
 777                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 778
 779                         if (br_lck) {
 780                                 brl_lock_cancel(br_lck,
 781                                         blr->lock_pid,
 782                                         procid_self(),
 783                                         blr->offset,
 784                                         blr->count,
 785                                         blr->lock_flav);
 786                                 TALLOC_FREE(br_lck);
 787                         }
 788
 789                         DLIST_REMOVE(blocking_lock_queue, blr);
 790                         free_blocking_lock_record(blr);
 791                         recalc_timeout = True;
 792                 }
 793                 change_to_root_user();
 794         }
 795
 796         if (recalc_timeout) {
 797                 recalc_brl_timeout();
 798         }
 799 }
 800
 801 /****************************************************************************
 802  Handle a cancel message. Lock already moved onto the cancel queue.
 803 *****************************************************************************/
 804
 805 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 806
 807 static void process_blocking_lock_cancel_message(int msg_type,
 808                                                  struct process_id src,
 809                                                  void *buf, size_t len,
 810                                                  void *private_data)
 811 {
 812         NTSTATUS err;
 813         const char *msg = (const char *)buf;
 814         blocking_lock_record *blr;
 815
 816         if (buf == NULL) {
 817                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 818         }
 819
 820         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 821                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 822                         "Got invalid msg len %d\n", (int)len));
 823                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 824         }
 825
 826         memcpy(&blr, msg, sizeof(blr));
 827         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 828
 829         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 830                 nt_errstr(err) ));
 831
 832         blocking_lock_reply_error(blr, err);
 833         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 834         free_blocking_lock_record(blr);
 835 }
 836
 837 /****************************************************************************
 838  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 839 *****************************************************************************/
 840
 841 BOOL blocking_lock_cancel(files_struct *fsp,
 842                         uint32 lock_pid,
 843                         SMB_BIG_UINT offset,
 844                         SMB_BIG_UINT count,
 845                         enum brl_flavour lock_flav,
 846                         unsigned char locktype,
 847                         NTSTATUS err)
 848 {
 849         static BOOL initialized;
 850         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 851         blocking_lock_record *blr;
 852
 853         if (!initialized) {
 854                 /* Register our message. */
 855                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 856                                  process_blocking_lock_cancel_message,
 857                                  NULL);
 858
 859                 initialized = True;
 860         }
 861
 862         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 863                 if (fsp == blr->fsp &&
 864                                 lock_pid == blr->lock_pid &&
 865                                 offset == blr->offset &&
 866                                 count == blr->count &&
 867                                 lock_flav == blr->lock_flav) {
 868                         break;
 869                 }
 870         }
 871
 872         if (!blr) {
 873                 return False;
 874         }
 875
 876         /* Check the flags are right. */
 877         if (blr->com_type == SMBlockingX &&
 878                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 879                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 880                 return False;
 881         }
 882
 883         /* Move to cancelled queue. */
 884         DLIST_REMOVE(blocking_lock_queue, blr);
 885         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 886
 887         /* Create the message. */
 888         memcpy(msg, &blr, sizeof(blr));
 889         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 890
 891         message_send_pid(pid_to_procid(sys_getpid()),
 892                         MSG_SMB_BLOCKING_LOCK_CANCEL,
 893                         &msg, sizeof(msg), True);
 894
 895         return True;
 896 }