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 /****************************************************************************
  26  This is the structure to queue to implement blocking locks.
  27  notify. It consists of the requesting SMB and the expiry time.
  28 *****************************************************************************/
  29
  30 typedef struct _blocking_lock_record {
  31         struct _blocking_lock_record *next;
  32         struct _blocking_lock_record *prev;
  33         int com_type;
  34         files_struct *fsp;
  35         struct timeval expire_time;
  36         int lock_num;
  37         SMB_BIG_UINT offset;
  38         SMB_BIG_UINT count;
  39         uint32 lock_pid;
  40         enum brl_flavour lock_flav;
  41         enum brl_type lock_type;
  42         char *inbuf;
  43         int length;
  44 } blocking_lock_record;
  45
  46 /* dlink list we store pending lock records on. */
  47 static blocking_lock_record *blocking_lock_queue;
  48
  49 /* dlink list we move cancelled lock records onto. */
  50 static blocking_lock_record *blocking_lock_cancelled_queue;
  51
  52 /****************************************************************************
  53  Destructor for the above structure.
  54 ****************************************************************************/
  55
  56 static void free_blocking_lock_record(blocking_lock_record *blr)
  57 {
  58         SAFE_FREE(blr->inbuf);
  59         SAFE_FREE(blr);
  60 }
  61
  62 /****************************************************************************
  63  Determine if this is a secondary element of a chained SMB.
  64   **************************************************************************/
  65
  66 static BOOL in_chained_smb(void)
  67 {
  68         return (chain_size != 0);
  69 }
  70
  71 static void received_unlock_msg(int msg_type, struct process_id src,
  72                                 void *buf, size_t len);
  73
  74 /****************************************************************************
  75  Function to push a blocking lock request onto the lock queue.
  76 ****************************************************************************/
  77
  78 BOOL push_blocking_lock_request( struct byte_range_lock *br_lck,
  79                 char *inbuf, int length,
  80                 files_struct *fsp,
  81                 int lock_timeout,
  82                 int lock_num,
  83                 uint32 lock_pid,
  84                 enum brl_type lock_type,
  85                 enum brl_flavour lock_flav,
  86                 SMB_BIG_UINT offset, SMB_BIG_UINT count)
  87 {
  88         static BOOL set_lock_msg;
  89         blocking_lock_record *blr, *tmp;
  90         NTSTATUS status;
  91
  92         if(in_chained_smb() ) {
  93                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
  94                 return False;
  95         }
  96
  97         /*
  98          * Now queue an entry on the blocking lock queue. We setup
  99          * the expiration time here.
 100          */
 101
 102         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 103                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 104                 return False;
 105         }
 106
 107         blr->next = NULL;
 108         blr->prev = NULL;
 109
 110         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 111                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 112                 SAFE_FREE(blr);
 113                 return False;
 114         }
 115
 116         blr->com_type = CVAL(inbuf,smb_com);
 117         blr->fsp = fsp;
 118         if (lock_timeout == -1) {
 119                 blr->expire_time.tv_sec = 0;
 120                 blr->expire_time.tv_usec = 0; /* Never expire. */
 121         } else {
 122                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 123                                         (lock_timeout % 1000) * 1000);
 124         }
 125         blr->lock_num = lock_num;
 126         blr->lock_pid = lock_pid;
 127         blr->lock_flav = lock_flav;
 128         blr->lock_type = lock_type;
 129         blr->offset = offset;
 130         blr->count = count;
 131         memcpy(blr->inbuf, inbuf, length);
 132         blr->length = length;
 133
 134         /* Add a pending lock record for this. */
 135         status = brl_lock(br_lck,
 136                         lock_pid,
 137                         procid_self(),
 138                         offset,
 139                         count,
 140                         PENDING_LOCK,
 141                         blr->lock_flav,
 142                         lock_timeout ? True : False); /* blocking_lock. */
 143
 144         if (!NT_STATUS_IS_OK(status)) {
 145                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 146                 DLIST_REMOVE(blocking_lock_queue, blr);
 147                 free_blocking_lock_record(blr);
 148                 return False;
 149         }
 150
 151         DLIST_ADD_END(blocking_lock_queue, blr, tmp);
 152
 153         /* Ensure we'll receive messages when this is unlocked. */
 154         if (!set_lock_msg) {
 155                 message_register(MSG_SMB_UNLOCK, received_unlock_msg);
 156                 set_lock_msg = True;
 157         }
 158
 159         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
 160                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 161                 length, (unsigned int)blr->expire_time.tv_sec,
 162                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 163                 blr->fsp->fnum, blr->fsp->fsp_name ));
 164
 165         /* Push the MID of this packet on the signing queue. */
 166         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 167
 168         return True;
 169 }
 170
 171 /****************************************************************************
 172  Return a smd with a given size.
 173 *****************************************************************************/
 174
 175 static void send_blocking_reply(char *outbuf, int outsize)
 176 {
 177         if(outsize > 4)
 178                 smb_setlen(outbuf,outsize - 4);
 179
 180         if (!send_smb(smbd_server_fd(),outbuf))
 181                 exit_server("send_blocking_reply: send_smb failed.");
 182 }
 183
 184 /****************************************************************************
 185  Return a lockingX success SMB.
 186 *****************************************************************************/
 187
 188 static void reply_lockingX_success(blocking_lock_record *blr)
 189 {
 190         char *outbuf = get_OutBuffer();
 191         int bufsize = BUFFER_SIZE;
 192         char *inbuf = blr->inbuf;
 193         int outsize = 0;
 194
 195         construct_reply_common(inbuf, outbuf);
 196         set_message(outbuf,2,0,True);
 197
 198         /*
 199          * As this message is a lockingX call we must handle
 200          * any following chained message correctly.
 201          * This is normally handled in construct_reply(),
 202          * but as that calls switch_message, we can't use
 203          * that here and must set up the chain info manually.
 204          */
 205
 206         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 207
 208         outsize += chain_size;
 209
 210         send_blocking_reply(outbuf,outsize);
 211 }
 212
 213 /****************************************************************************
 214  Return a generic lock fail error blocking call.
 215 *****************************************************************************/
 216
 217 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 218 {
 219         char *outbuf = get_OutBuffer();
 220         char *inbuf = blr->inbuf;
 221         construct_reply_common(inbuf, outbuf);
 222
 223         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 224            FILE_LOCK_CONFLICT! (tridge) */
 225         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 226                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 227         }
 228
 229         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 230                 /* Store the last lock error. */
 231                 files_struct *fsp = blr->fsp;
 232
 233                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 234                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 235                 fsp->last_lock_failure.context.pid = procid_self();
 236                 fsp->last_lock_failure.start = blr->offset;
 237                 fsp->last_lock_failure.size = blr->count;
 238                 fsp->last_lock_failure.fnum = fsp->fnum;
 239                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 240                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 241         }
 242
 243         ERROR_NT(status);
 244         if (!send_smb(smbd_server_fd(),outbuf)) {
 245                 exit_server("generic_blocking_lock_error: send_smb failed.");
 246         }
 247 }
 248
 249 /****************************************************************************
 250  Return a lock fail error for a lockingX call. Undo all the locks we have
 251  obtained first.
 252 *****************************************************************************/
 253
 254 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 255 {
 256         char *inbuf = blr->inbuf;
 257         files_struct *fsp = blr->fsp;
 258         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 259         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 260         uint32 lock_pid;
 261         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 262         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 263         char *data;
 264         int i;
 265
 266         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 267
 268         /*
 269          * Data now points at the beginning of the list
 270          * of smb_lkrng structs.
 271          */
 272
 273         /*
 274          * Ensure we don't do a remove on the lock that just failed,
 275          * as under POSIX rules, if we have a lock already there, we
 276          * will delete it (and we shouldn't) .....
 277          */
 278
 279         for(i = blr->lock_num - 1; i >= 0; i--) {
 280                 BOOL err;
 281
 282                 lock_pid = get_lock_pid( data, i, large_file_format);
 283                 count = get_lock_count( data, i, large_file_format);
 284                 offset = get_lock_offset( data, i, large_file_format, &err);
 285
 286                 /*
 287                  * We know err cannot be set as if it was the lock
 288                  * request would never have been queued. JRA.
 289                  */
 290
 291                 do_unlock(fsp,
 292                         lock_pid,
 293                         count,
 294                         offset,
 295                         WINDOWS_LOCK);
 296         }
 297
 298         generic_blocking_lock_error(blr, status);
 299 }
 300
 301 /****************************************************************************
 302  Return a lock fail error.
 303 *****************************************************************************/
 304
 305 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 306 {
 307         switch(blr->com_type) {
 308         case SMBlockingX:
 309                 reply_lockingX_error(blr, status);
 310                 break;
 311         case SMBtrans2:
 312         case SMBtranss2:
 313                 {
 314                         char *outbuf = get_OutBuffer();
 315                         char *inbuf = blr->inbuf;
 316                         construct_reply_common(inbuf, outbuf);
 317                         /* construct_reply_common has done us the favor to pre-fill the
 318                          * command field with SMBtranss2 which is wrong :-)
 319                          */
 320                         SCVAL(outbuf,smb_com,SMBtrans2);
 321                         ERROR_NT(status);
 322                         if (!send_smb(smbd_server_fd(),outbuf)) {
 323                                 exit_server("blocking_lock_reply_error: send_smb failed.");
 324                         }
 325                         break;
 326                 }
 327         default:
 328                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 329                 exit_server("PANIC - unknown type on blocking lock queue");
 330         }
 331 }
 332
 333 /****************************************************************************
 334  Attempt to finish off getting all pending blocking locks for a lockingX call.
 335  Returns True if we want to be removed from the list.
 336 *****************************************************************************/
 337
 338 static BOOL process_lockingX(blocking_lock_record *blr)
 339 {
 340         char *inbuf = blr->inbuf;
 341         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 342         files_struct *fsp = blr->fsp;
 343         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 344         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 345         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 346         uint32 lock_pid;
 347         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 348         char *data;
 349         NTSTATUS status = NT_STATUS_OK;
 350
 351         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 352
 353         /*
 354          * Data now points at the beginning of the list
 355          * of smb_lkrng structs.
 356          */
 357
 358         for(; blr->lock_num < num_locks; blr->lock_num++) {
 359                 struct byte_range_lock *br_lck = NULL;
 360                 BOOL err;
 361
 362                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 363                 count = get_lock_count( data, blr->lock_num, large_file_format);
 364                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 365
 366                 /*
 367                  * We know err cannot be set as if it was the lock
 368                  * request would never have been queued. JRA.
 369                  */
 370                 errno = 0;
 371                 br_lck = do_lock(fsp,
 372                                 lock_pid,
 373                                 count,
 374                                 offset,
 375                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 376                                         READ_LOCK : WRITE_LOCK),
 377                                 WINDOWS_LOCK,
 378                                 True,
 379                                 &status);
 380
 381                 TALLOC_FREE(br_lck);
 382
 383                 if (NT_STATUS_IS_ERR(status)) {
 384                         break;
 385                 }
 386         }
 387
 388         if(blr->lock_num == num_locks) {
 389                 /*
 390                  * Success - we got all the locks.
 391                  */
 392
 393                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 394                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 395
 396                 reply_lockingX_success(blr);
 397                 return True;
 398         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 399                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 400                         /*
 401                          * We have other than a "can't get lock"
 402                          * error. Free any locks we had and return an error.
 403                          * Return True so we get dequeued.
 404                          */
 405
 406                 blocking_lock_reply_error(blr, status);
 407                 return True;
 408         }
 409
 410         /*
 411          * Still can't get all the locks - keep waiting.
 412          */
 413
 414         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 415 Waiting....\n",
 416                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 417
 418         return False;
 419 }
 420
 421 /****************************************************************************
 422  Attempt to get the posix lock request from a SMBtrans2 call.
 423  Returns True if we want to be removed from the list.
 424 *****************************************************************************/
 425
 426 static BOOL process_trans2(blocking_lock_record *blr)
 427 {
 428         extern int max_send;
 429         char *inbuf = blr->inbuf;
 430         char *outbuf;
 431         char params[2];
 432         NTSTATUS status;
 433         struct byte_range_lock *br_lck = do_lock(blr->fsp,
 434                                                 blr->lock_pid,
 435                                                 blr->count,
 436                                                 blr->offset,
 437                                                 blr->lock_type,
 438                                                 blr->lock_flav,
 439                                                 True,
 440                                                 &status);
 441         TALLOC_FREE(br_lck);
 442
 443         if (!NT_STATUS_IS_OK(status)) {
 444                 if (ERROR_WAS_LOCK_DENIED(status)) {
 445                         /* Still can't get the lock, just keep waiting. */
 446                         return False;
 447                 }
 448                 /*
 449                  * We have other than a "can't get lock"
 450                  * error. Send an error and return True so we get dequeued.
 451                  */
 452                 blocking_lock_reply_error(blr, status);
 453                 return True;
 454         }
 455
 456         /* We finally got the lock, return success. */
 457         outbuf = get_OutBuffer();
 458         construct_reply_common(inbuf, outbuf);
 459         SCVAL(outbuf,smb_com,SMBtrans2);
 460         SSVAL(params,0,0);
 461         send_trans2_replies(outbuf, max_send, params, 2, NULL, 0);
 462         return True;
 463 }
 464
 465
 466 /****************************************************************************
 467  Process a blocking lock SMB.
 468  Returns True if we want to be removed from the list.
 469 *****************************************************************************/
 470
 471 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 472 {
 473         switch(blr->com_type) {
 474                 case SMBlockingX:
 475                         return process_lockingX(blr);
 476                 case SMBtrans2:
 477                 case SMBtranss2:
 478                         return process_trans2(blr);
 479                 default:
 480                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 481                         exit_server("PANIC - unknown type on blocking lock queue");
 482         }
 483         return False; /* Keep compiler happy. */
 484 }
 485
 486 /****************************************************************************
 487  Cancel entries by fnum from the blocking lock pending queue.
 488 *****************************************************************************/
 489
 490 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 491 {
 492         blocking_lock_record *blr, *next = NULL;
 493
 494         for(blr = blocking_lock_queue; blr; blr = next) {
 495                 next = blr->next;
 496                 if(blr->fsp->fnum == fsp->fnum) {
 497                         unsigned char locktype = 0;
 498
 499                         if (blr->com_type == SMBlockingX) {
 500                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 501                         }
 502
 503                         if (br_lck) {
 504                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 505 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 506
 507                                 brl_lock_cancel(br_lck,
 508                                         blr->lock_pid,
 509                                         procid_self(),
 510                                         blr->offset,
 511                                         blr->count,
 512                                         blr->lock_flav);
 513
 514                                 blocking_lock_cancel(fsp,
 515                                         blr->lock_pid,
 516                                         blr->offset,
 517                                         blr->count,
 518                                         blr->lock_flav,
 519                                         locktype,
 520                                         NT_STATUS_RANGE_NOT_LOCKED);
 521                         }
 522                 }
 523         }
 524 }
 525
 526 /****************************************************************************
 527  Delete entries by mid from the blocking lock pending queue. Always send reply.
 528 *****************************************************************************/
 529
 530 void remove_pending_lock_requests_by_mid(int mid)
 531 {
 532         blocking_lock_record *blr, *next = NULL;
 533
 534         for(blr = blocking_lock_queue; blr; blr = next) {
 535                 next = blr->next;
 536                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 537                         files_struct *fsp = blr->fsp;
 538                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 539
 540                         if (br_lck) {
 541                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 542 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 543
 544                                 brl_lock_cancel(br_lck,
 545                                         blr->lock_pid,
 546                                         procid_self(),
 547                                         blr->offset,
 548                                         blr->count,
 549                                         blr->lock_flav);
 550                                 TALLOC_FREE(br_lck);
 551                         }
 552
 553                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 554                         DLIST_REMOVE(blocking_lock_queue, blr);
 555                         free_blocking_lock_record(blr);
 556                 }
 557         }
 558 }
 559
 560 /****************************************************************************
 561   Set a flag as an unlock request affects one of our pending locks.
 562 *****************************************************************************/
 563
 564 static void received_unlock_msg(int msg_type, struct process_id src,
 565                                 void *buf, size_t len)
 566 {
 567         DEBUG(10,("received_unlock_msg\n"));
 568         process_blocking_lock_queue();
 569 }
 570
 571 /****************************************************************************
 572  Return the number of milliseconds to the next blocking locks timeout, or default_timeout
 573 *****************************************************************************/
 574
 575 unsigned int blocking_locks_timeout_ms(unsigned int default_timeout_ms)
 576 {
 577         unsigned int timeout_ms = default_timeout_ms;
 578         struct timeval tv_curr;
 579         SMB_BIG_INT min_tv_dif_us = 0x7FFFFFFF; /* A large +ve number. */
 580         blocking_lock_record *blr = blocking_lock_queue;
 581
 582         /* note that we avoid the GetTimeOfDay() syscall if there are no blocking locks */
 583         if (!blr) {
 584                 return timeout_ms;
 585         }
 586
 587         tv_curr = timeval_current();
 588
 589         for (; blr; blr = blr->next) {
 590                 SMB_BIG_INT tv_dif_us;
 591
 592                 if (timeval_is_zero(&blr->expire_time)) {
 593                         continue; /* Never timeout. */
 594                 }
 595
 596                 tv_dif_us = usec_time_diff(&blr->expire_time, &tv_curr);
 597                 min_tv_dif_us = MIN(min_tv_dif_us, tv_dif_us);
 598         }
 599
 600         if (min_tv_dif_us < 0) {
 601                 min_tv_dif_us = 0;
 602         }
 603
 604         timeout_ms = (unsigned int)(min_tv_dif_us / (SMB_BIG_INT)1000);
 605
 606         if (timeout_ms < 1) {
 607                 timeout_ms = 1;
 608         }
 609
 610         DEBUG(10,("blocking_locks_timeout_ms: returning %u\n", timeout_ms));
 611
 612         return timeout_ms;
 613 }
 614
 615 /****************************************************************************
 616  Process the blocking lock queue. Note that this is only called as root.
 617 *****************************************************************************/
 618
 619 void process_blocking_lock_queue(void)
 620 {
 621         struct timeval tv_curr = timeval_current();
 622         blocking_lock_record *blr, *next = NULL;
 623
 624         /*
 625          * Go through the queue and see if we can get any of the locks.
 626          */
 627
 628         for (blr = blocking_lock_queue; blr; blr = next) {
 629                 connection_struct *conn = NULL;
 630                 uint16 vuid;
 631                 files_struct *fsp = NULL;
 632
 633                 next = blr->next;
 634
 635                 /*
 636                  * Ensure we don't have any old chain_fsp values
 637                  * sitting around....
 638                  */
 639                 chain_size = 0;
 640                 file_chain_reset();
 641                 fsp = blr->fsp;
 642
 643                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 644                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 645                                 SVAL(blr->inbuf,smb_uid);
 646
 647                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 648                         fsp->fnum, fsp->fsp_name ));
 649
 650                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 651                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 652
 653                         /*
 654                          * Lock expired - throw away all previously
 655                          * obtained locks and return lock error.
 656                          */
 657
 658                         if (br_lck) {
 659                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 660                                         fsp->fnum, fsp->fsp_name ));
 661
 662                                 brl_lock_cancel(br_lck,
 663                                         blr->lock_pid,
 664                                         procid_self(),
 665                                         blr->offset,
 666                                         blr->count,
 667                                         blr->lock_flav);
 668                                 TALLOC_FREE(br_lck);
 669                         }
 670
 671                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 672                         DLIST_REMOVE(blocking_lock_queue, blr);
 673                         free_blocking_lock_record(blr);
 674                         continue;
 675                 }
 676
 677                 if(!change_to_user(conn,vuid)) {
 678                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 679
 680                         /*
 681                          * Remove the entry and return an error to the client.
 682                          */
 683
 684                         if (br_lck) {
 685                                 brl_lock_cancel(br_lck,
 686                                         blr->lock_pid,
 687                                         procid_self(),
 688                                         blr->offset,
 689                                         blr->count,
 690                                         blr->lock_flav);
 691                                 TALLOC_FREE(br_lck);
 692                         }
 693
 694                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 695                                 vuid ));
 696                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 697                         DLIST_REMOVE(blocking_lock_queue, blr);
 698                         free_blocking_lock_record(blr);
 699                         continue;
 700                 }
 701
 702                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 703                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 704
 705                         /*
 706                          * Remove the entry and return an error to the client.
 707                          */
 708
 709                         if (br_lck) {
 710                                 brl_lock_cancel(br_lck,
 711                                         blr->lock_pid,
 712                                         procid_self(),
 713                                         blr->offset,
 714                                         blr->count,
 715                                         blr->lock_flav);
 716                                 TALLOC_FREE(br_lck);
 717                         }
 718
 719                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 720                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 721                         DLIST_REMOVE(blocking_lock_queue, blr);
 722                         free_blocking_lock_record(blr);
 723                         change_to_root_user();
 724                         continue;
 725                 }
 726
 727                 /*
 728                  * Go through the remaining locks and try and obtain them.
 729                  * The call returns True if all locks were obtained successfully
 730                  * and False if we still need to wait.
 731                  */
 732
 733                 if(blocking_lock_record_process(blr)) {
 734                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 735
 736                         if (br_lck) {
 737                                 brl_lock_cancel(br_lck,
 738                                         blr->lock_pid,
 739                                         procid_self(),
 740                                         blr->offset,
 741                                         blr->count,
 742                                         blr->lock_flav);
 743                                 TALLOC_FREE(br_lck);
 744                         }
 745
 746                         DLIST_REMOVE(blocking_lock_queue, blr);
 747                         free_blocking_lock_record(blr);
 748                 }
 749                 change_to_root_user();
 750         }
 751 }
 752
 753 /****************************************************************************
 754  Handle a cancel message. Lock already moved onto the cancel queue.
 755 *****************************************************************************/
 756
 757 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 758
 759 static void process_blocking_lock_cancel_message(int msg_type, struct process_id src,
 760                                          void *buf, size_t len)
 761 {
 762         NTSTATUS err;
 763         const char *msg = (const char *)buf;
 764         blocking_lock_record *blr;
 765
 766         if (buf == NULL) {
 767                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 768         }
 769
 770         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 771                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 772                         "Got invalid msg len %d\n", (int)len));
 773                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 774         }
 775
 776         memcpy(&blr, msg, sizeof(blr));
 777         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 778
 779         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 780                 nt_errstr(err) ));
 781
 782         blocking_lock_reply_error(blr, err);
 783         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 784         free_blocking_lock_record(blr);
 785 }
 786
 787 /****************************************************************************
 788  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 789 *****************************************************************************/
 790
 791 BOOL blocking_lock_cancel(files_struct *fsp,
 792                         uint32 lock_pid,
 793                         SMB_BIG_UINT offset,
 794                         SMB_BIG_UINT count,
 795                         enum brl_flavour lock_flav,
 796                         unsigned char locktype,
 797                         NTSTATUS err)
 798 {
 799         static BOOL initialized;
 800         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 801         blocking_lock_record *blr;
 802
 803         if (!initialized) {
 804                 /* Register our message. */
 805                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 806                                 process_blocking_lock_cancel_message);
 807
 808                 initialized = True;
 809         }
 810
 811         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 812                 if (fsp == blr->fsp &&
 813                                 lock_pid == blr->lock_pid &&
 814                                 offset == blr->offset &&
 815                                 count == blr->count &&
 816                                 lock_flav == blr->lock_flav) {
 817                         break;
 818                 }
 819         }
 820
 821         if (!blr) {
 822                 return False;
 823         }
 824
 825         /* Check the flags are right. */
 826         if (blr->com_type == SMBlockingX &&
 827                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 828                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 829                 return False;
 830         }
 831
 832         /* Move to cancelled queue. */
 833         DLIST_REMOVE(blocking_lock_queue, blr);
 834         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 835
 836         /* Create the message. */
 837         memcpy(msg, &blr, sizeof(blr));
 838         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 839
 840         /* Don't need to be root here as we're only ever
 841                 sending to ourselves. */
 842
 843         message_send_pid(pid_to_procid(sys_getpid()),
 844                         MSG_SMB_BLOCKING_LOCK_CANCEL,
 845                         &msg, sizeof(msg), True);
 846
 847         return True;
 848 }