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 /****************************************************************************
  55  Destructor for the above structure.
  56 ****************************************************************************/
  57
  58 static void free_blocking_lock_record(blocking_lock_record *blr)
  59 {
  60         SAFE_FREE(blr->inbuf);
  61         SAFE_FREE(blr);
  62 }
  63
  64 /****************************************************************************
  65  Determine if this is a secondary element of a chained SMB.
  66   **************************************************************************/
  67
  68 static BOOL in_chained_smb(void)
  69 {
  70         return (chain_size != 0);
  71 }
  72
  73 static void received_unlock_msg(int msg_type, struct process_id src,
  74                                 void *buf, size_t len,
  75                                 void *private_data);
  76
  77 /****************************************************************************
  78  Function to push a blocking lock request onto the lock queue.
  79 ****************************************************************************/
  80
  81 BOOL push_blocking_lock_request( struct byte_range_lock *br_lck,
  82                 char *inbuf, int length,
  83                 files_struct *fsp,
  84                 int lock_timeout,
  85                 int lock_num,
  86                 uint32 lock_pid,
  87                 enum brl_type lock_type,
  88                 enum brl_flavour lock_flav,
  89                 SMB_BIG_UINT offset, SMB_BIG_UINT count)
  90 {
  91         static BOOL set_lock_msg;
  92         blocking_lock_record *blr;
  93         NTSTATUS status;
  94
  95         if(in_chained_smb() ) {
  96                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
  97                 return False;
  98         }
  99
 100         /*
 101          * Now queue an entry on the blocking lock queue. We setup
 102          * the expiration time here.
 103          */
 104
 105         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 106                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 107                 return False;
 108         }
 109
 110         blr->next = NULL;
 111         blr->prev = NULL;
 112
 113         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 114                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 115                 SAFE_FREE(blr);
 116                 return False;
 117         }
 118
 119         blr->com_type = CVAL(inbuf,smb_com);
 120         blr->fsp = fsp;
 121         if (lock_timeout == -1) {
 122                 blr->expire_time.tv_sec = 0;
 123                 blr->expire_time.tv_usec = 0; /* Never expire. */
 124         } else {
 125                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 126                                         (lock_timeout % 1000) * 1000);
 127         }
 128         blr->lock_num = lock_num;
 129         blr->lock_pid = lock_pid;
 130         blr->lock_flav = lock_flav;
 131         blr->lock_type = lock_type;
 132         blr->offset = offset;
 133         blr->count = count;
 134         memcpy(blr->inbuf, inbuf, length);
 135         blr->length = length;
 136
 137         /* Add a pending lock record for this. */
 138         status = brl_lock(br_lck,
 139                         lock_pid,
 140                         procid_self(),
 141                         offset,
 142                         count,
 143                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 144                         blr->lock_flav,
 145                         lock_timeout ? True : False); /* blocking_lock. */
 146
 147         if (!NT_STATUS_IS_OK(status)) {
 148                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 149                 DLIST_REMOVE(blocking_lock_queue, blr);
 150                 free_blocking_lock_record(blr);
 151                 return False;
 152         }
 153
 154         DLIST_ADD_END(blocking_lock_queue, blr, blocking_lock_record *);
 155
 156         /* Ensure we'll receive messages when this is unlocked. */
 157         if (!set_lock_msg) {
 158                 message_register(MSG_SMB_UNLOCK, received_unlock_msg,
 159                                  NULL);
 160                 set_lock_msg = True;
 161         }
 162
 163         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
 164                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 165                 length, (unsigned int)blr->expire_time.tv_sec,
 166                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 167                 blr->fsp->fnum, blr->fsp->fsp_name ));
 168
 169         /* Push the MID of this packet on the signing queue. */
 170         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 171
 172         return True;
 173 }
 174
 175 /****************************************************************************
 176  Return a smd with a given size.
 177 *****************************************************************************/
 178
 179 static void send_blocking_reply(char *outbuf, int outsize)
 180 {
 181         if(outsize > 4)
 182                 smb_setlen(outbuf,outsize - 4);
 183
 184         if (!send_smb(smbd_server_fd(),outbuf))
 185                 exit_server_cleanly("send_blocking_reply: send_smb failed.");
 186 }
 187
 188 /****************************************************************************
 189  Return a lockingX success SMB.
 190 *****************************************************************************/
 191
 192 static void reply_lockingX_success(blocking_lock_record *blr)
 193 {
 194         char *outbuf = get_OutBuffer();
 195         int bufsize = BUFFER_SIZE;
 196         char *inbuf = blr->inbuf;
 197         int outsize = 0;
 198
 199         construct_reply_common(inbuf, outbuf);
 200         set_message(outbuf,2,0,True);
 201
 202         /*
 203          * As this message is a lockingX call we must handle
 204          * any following chained message correctly.
 205          * This is normally handled in construct_reply(),
 206          * but as that calls switch_message, we can't use
 207          * that here and must set up the chain info manually.
 208          */
 209
 210         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 211
 212         outsize += chain_size;
 213
 214         send_blocking_reply(outbuf,outsize);
 215 }
 216
 217 /****************************************************************************
 218  Return a generic lock fail error blocking call.
 219 *****************************************************************************/
 220
 221 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 222 {
 223         char *outbuf = get_OutBuffer();
 224         char *inbuf = blr->inbuf;
 225         construct_reply_common(inbuf, outbuf);
 226
 227         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 228            FILE_LOCK_CONFLICT! (tridge) */
 229         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 230                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 231         }
 232
 233         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 234                 /* Store the last lock error. */
 235                 files_struct *fsp = blr->fsp;
 236
 237                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 238                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 239                 fsp->last_lock_failure.context.pid = procid_self();
 240                 fsp->last_lock_failure.start = blr->offset;
 241                 fsp->last_lock_failure.size = blr->count;
 242                 fsp->last_lock_failure.fnum = fsp->fnum;
 243                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 244                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 245         }
 246
 247         ERROR_NT(status);
 248         if (!send_smb(smbd_server_fd(),outbuf)) {
 249                 exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
 250         }
 251 }
 252
 253 /****************************************************************************
 254  Return a lock fail error for a lockingX call. Undo all the locks we have
 255  obtained first.
 256 *****************************************************************************/
 257
 258 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 259 {
 260         char *inbuf = blr->inbuf;
 261         files_struct *fsp = blr->fsp;
 262         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 263         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 264         uint32 lock_pid;
 265         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 266         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 267         char *data;
 268         int i;
 269
 270         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 271
 272         /*
 273          * Data now points at the beginning of the list
 274          * of smb_lkrng structs.
 275          */
 276
 277         /*
 278          * Ensure we don't do a remove on the lock that just failed,
 279          * as under POSIX rules, if we have a lock already there, we
 280          * will delete it (and we shouldn't) .....
 281          */
 282
 283         for(i = blr->lock_num - 1; i >= 0; i--) {
 284                 BOOL err;
 285
 286                 lock_pid = get_lock_pid( data, i, large_file_format);
 287                 count = get_lock_count( data, i, large_file_format);
 288                 offset = get_lock_offset( data, i, large_file_format, &err);
 289
 290                 /*
 291                  * We know err cannot be set as if it was the lock
 292                  * request would never have been queued. JRA.
 293                  */
 294
 295                 do_unlock(fsp,
 296                         lock_pid,
 297                         count,
 298                         offset,
 299                         WINDOWS_LOCK);
 300         }
 301
 302         generic_blocking_lock_error(blr, status);
 303 }
 304
 305 /****************************************************************************
 306  Return a lock fail error.
 307 *****************************************************************************/
 308
 309 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 310 {
 311         switch(blr->com_type) {
 312         case SMBlockingX:
 313                 reply_lockingX_error(blr, status);
 314                 break;
 315         case SMBtrans2:
 316         case SMBtranss2:
 317                 {
 318                         char *outbuf = get_OutBuffer();
 319                         char *inbuf = blr->inbuf;
 320                         construct_reply_common(inbuf, outbuf);
 321                         /* construct_reply_common has done us the favor to pre-fill the
 322                          * command field with SMBtranss2 which is wrong :-)
 323                          */
 324                         SCVAL(outbuf,smb_com,SMBtrans2);
 325                         ERROR_NT(status);
 326                         if (!send_smb(smbd_server_fd(),outbuf)) {
 327                                 exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
 328                         }
 329                         break;
 330                 }
 331         default:
 332                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 333                 exit_server("PANIC - unknown type on blocking lock queue");
 334         }
 335 }
 336
 337 /****************************************************************************
 338  Attempt to finish off getting all pending blocking locks for a lockingX call.
 339  Returns True if we want to be removed from the list.
 340 *****************************************************************************/
 341
 342 static BOOL process_lockingX(blocking_lock_record *blr)
 343 {
 344         char *inbuf = blr->inbuf;
 345         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 346         files_struct *fsp = blr->fsp;
 347         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 348         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 349         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 350         uint32 lock_pid;
 351         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 352         char *data;
 353         NTSTATUS status = NT_STATUS_OK;
 354
 355         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 356
 357         /*
 358          * Data now points at the beginning of the list
 359          * of smb_lkrng structs.
 360          */
 361
 362         for(; blr->lock_num < num_locks; blr->lock_num++) {
 363                 struct byte_range_lock *br_lck = NULL;
 364                 BOOL err;
 365
 366                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 367                 count = get_lock_count( data, blr->lock_num, large_file_format);
 368                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 369
 370                 /*
 371                  * We know err cannot be set as if it was the lock
 372                  * request would never have been queued. JRA.
 373                  */
 374                 errno = 0;
 375                 br_lck = do_lock(fsp,
 376                                 lock_pid,
 377                                 count,
 378                                 offset,
 379                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 380                                         READ_LOCK : WRITE_LOCK),
 381                                 WINDOWS_LOCK,
 382                                 True,
 383                                 &status);
 384
 385                 TALLOC_FREE(br_lck);
 386
 387                 if (NT_STATUS_IS_ERR(status)) {
 388                         break;
 389                 }
 390         }
 391
 392         if(blr->lock_num == num_locks) {
 393                 /*
 394                  * Success - we got all the locks.
 395                  */
 396
 397                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 398                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 399
 400                 reply_lockingX_success(blr);
 401                 return True;
 402         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 403                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 404                         /*
 405                          * We have other than a "can't get lock"
 406                          * error. Free any locks we had and return an error.
 407                          * Return True so we get dequeued.
 408                          */
 409
 410                 blocking_lock_reply_error(blr, status);
 411                 return True;
 412         }
 413
 414         /*
 415          * Still can't get all the locks - keep waiting.
 416          */
 417
 418         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 419 Waiting....\n",
 420                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 421
 422         return False;
 423 }
 424
 425 /****************************************************************************
 426  Attempt to get the posix lock request from a SMBtrans2 call.
 427  Returns True if we want to be removed from the list.
 428 *****************************************************************************/
 429
 430 static BOOL process_trans2(blocking_lock_record *blr)
 431 {
 432         char *inbuf = blr->inbuf;
 433         char *outbuf;
 434         char params[2];
 435         NTSTATUS status;
 436         struct byte_range_lock *br_lck = do_lock(blr->fsp,
 437                                                 blr->lock_pid,
 438                                                 blr->count,
 439                                                 blr->offset,
 440                                                 blr->lock_type,
 441                                                 blr->lock_flav,
 442                                                 True,
 443                                                 &status);
 444         TALLOC_FREE(br_lck);
 445
 446         if (!NT_STATUS_IS_OK(status)) {
 447                 if (ERROR_WAS_LOCK_DENIED(status)) {
 448                         /* Still can't get the lock, just keep waiting. */
 449                         return False;
 450                 }
 451                 /*
 452                  * We have other than a "can't get lock"
 453                  * error. Send an error and return True so we get dequeued.
 454                  */
 455                 blocking_lock_reply_error(blr, status);
 456                 return True;
 457         }
 458
 459         /* We finally got the lock, return success. */
 460         outbuf = get_OutBuffer();
 461         construct_reply_common(inbuf, outbuf);
 462         SCVAL(outbuf,smb_com,SMBtrans2);
 463         SSVAL(params,0,0);
 464         /* Fake up max_data_bytes here - we know it fits. */
 465         send_trans2_replies(outbuf, max_send, params, 2, NULL, 0, 0xffff);
 466         return True;
 467 }
 468
 469
 470 /****************************************************************************
 471  Process a blocking lock SMB.
 472  Returns True if we want to be removed from the list.
 473 *****************************************************************************/
 474
 475 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 476 {
 477         switch(blr->com_type) {
 478                 case SMBlockingX:
 479                         return process_lockingX(blr);
 480                 case SMBtrans2:
 481                 case SMBtranss2:
 482                         return process_trans2(blr);
 483                 default:
 484                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 485                         exit_server("PANIC - unknown type on blocking lock queue");
 486         }
 487         return False; /* Keep compiler happy. */
 488 }
 489
 490 /****************************************************************************
 491  Cancel entries by fnum from the blocking lock pending queue.
 492 *****************************************************************************/
 493
 494 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 495 {
 496         blocking_lock_record *blr, *next = NULL;
 497
 498         for(blr = blocking_lock_queue; blr; blr = next) {
 499                 next = blr->next;
 500                 if(blr->fsp->fnum == fsp->fnum) {
 501                         unsigned char locktype = 0;
 502
 503                         if (blr->com_type == SMBlockingX) {
 504                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 505                         }
 506
 507                         if (br_lck) {
 508                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 509 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 510
 511                                 brl_lock_cancel(br_lck,
 512                                         blr->lock_pid,
 513                                         procid_self(),
 514                                         blr->offset,
 515                                         blr->count,
 516                                         blr->lock_flav);
 517
 518                                 blocking_lock_cancel(fsp,
 519                                         blr->lock_pid,
 520                                         blr->offset,
 521                                         blr->count,
 522                                         blr->lock_flav,
 523                                         locktype,
 524                                         NT_STATUS_RANGE_NOT_LOCKED);
 525                         }
 526                 }
 527         }
 528 }
 529
 530 /****************************************************************************
 531  Delete entries by mid from the blocking lock pending queue. Always send reply.
 532 *****************************************************************************/
 533
 534 void remove_pending_lock_requests_by_mid(int mid)
 535 {
 536         blocking_lock_record *blr, *next = NULL;
 537
 538         for(blr = blocking_lock_queue; blr; blr = next) {
 539                 next = blr->next;
 540                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 541                         files_struct *fsp = blr->fsp;
 542                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 543
 544                         if (br_lck) {
 545                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 546 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 547
 548                                 brl_lock_cancel(br_lck,
 549                                         blr->lock_pid,
 550                                         procid_self(),
 551                                         blr->offset,
 552                                         blr->count,
 553                                         blr->lock_flav);
 554                                 TALLOC_FREE(br_lck);
 555                         }
 556
 557                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 558                         DLIST_REMOVE(blocking_lock_queue, blr);
 559                         free_blocking_lock_record(blr);
 560                 }
 561         }
 562 }
 563
 564 /****************************************************************************
 565  Is this mid a blocking lock request on the queue ?
 566 *****************************************************************************/
 567
 568 BOOL blocking_lock_was_deferred(int mid)
 569 {
 570         blocking_lock_record *blr, *next = NULL;
 571
 572         for(blr = blocking_lock_queue; blr; blr = next) {
 573                 next = blr->next;
 574                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 575                         return True;
 576                 }
 577         }
 578         return False;
 579 }
 580
 581 /****************************************************************************
 582   Set a flag as an unlock request affects one of our pending locks.
 583 *****************************************************************************/
 584
 585 static void received_unlock_msg(int msg_type, struct process_id src,
 586                                 void *buf, size_t len,
 587                                 void *private_data)
 588 {
 589         DEBUG(10,("received_unlock_msg\n"));
 590         process_blocking_lock_queue();
 591 }
 592
 593 /****************************************************************************
 594  Return the number of milliseconds to the next blocking locks timeout, or default_timeout
 595 *****************************************************************************/
 596
 597 unsigned int blocking_locks_timeout_ms(unsigned int default_timeout_ms)
 598 {
 599         unsigned int timeout_ms = default_timeout_ms;
 600         struct timeval tv_curr;
 601         SMB_BIG_INT min_tv_dif_us = 0x7FFFFFFF; /* A large +ve number. */
 602         blocking_lock_record *blr = blocking_lock_queue;
 603
 604         /* note that we avoid the GetTimeOfDay() syscall if there are no blocking locks */
 605         if (!blr) {
 606                 return timeout_ms;
 607         }
 608
 609         tv_curr = timeval_current();
 610
 611         for (; blr; blr = blr->next) {
 612                 SMB_BIG_INT tv_dif_us;
 613
 614                 if (timeval_is_zero(&blr->expire_time)) {
 615                         continue; /* Never timeout. */
 616                 }
 617
 618                 tv_dif_us = usec_time_diff(&blr->expire_time, &tv_curr);
 619                 min_tv_dif_us = MIN(min_tv_dif_us, tv_dif_us);
 620         }
 621
 622         if (min_tv_dif_us < 0) {
 623                 min_tv_dif_us = 0;
 624         }
 625
 626         timeout_ms = (unsigned int)(min_tv_dif_us / (SMB_BIG_INT)1000);
 627
 628         if (timeout_ms < 1) {
 629                 timeout_ms = 1;
 630         }
 631
 632         DEBUG(10,("blocking_locks_timeout_ms: returning %u\n", timeout_ms));
 633
 634         return timeout_ms;
 635 }
 636
 637 /****************************************************************************
 638  Process the blocking lock queue. Note that this is only called as root.
 639 *****************************************************************************/
 640
 641 void process_blocking_lock_queue(void)
 642 {
 643         struct timeval tv_curr = timeval_current();
 644         blocking_lock_record *blr, *next = NULL;
 645
 646         /*
 647          * Go through the queue and see if we can get any of the locks.
 648          */
 649
 650         for (blr = blocking_lock_queue; blr; blr = next) {
 651                 connection_struct *conn = NULL;
 652                 uint16 vuid;
 653                 files_struct *fsp = NULL;
 654
 655                 next = blr->next;
 656
 657                 /*
 658                  * Ensure we don't have any old chain_fsp values
 659                  * sitting around....
 660                  */
 661                 chain_size = 0;
 662                 file_chain_reset();
 663                 fsp = blr->fsp;
 664
 665                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 666                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 667                                 SVAL(blr->inbuf,smb_uid);
 668
 669                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 670                         fsp->fnum, fsp->fsp_name ));
 671
 672                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 673                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 674
 675                         /*
 676                          * Lock expired - throw away all previously
 677                          * obtained locks and return lock error.
 678                          */
 679
 680                         if (br_lck) {
 681                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 682                                         fsp->fnum, fsp->fsp_name ));
 683
 684                                 brl_lock_cancel(br_lck,
 685                                         blr->lock_pid,
 686                                         procid_self(),
 687                                         blr->offset,
 688                                         blr->count,
 689                                         blr->lock_flav);
 690                                 TALLOC_FREE(br_lck);
 691                         }
 692
 693                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 694                         DLIST_REMOVE(blocking_lock_queue, blr);
 695                         free_blocking_lock_record(blr);
 696                         continue;
 697                 }
 698
 699                 if(!change_to_user(conn,vuid)) {
 700                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 701
 702                         /*
 703                          * Remove the entry and return an error to the client.
 704                          */
 705
 706                         if (br_lck) {
 707                                 brl_lock_cancel(br_lck,
 708                                         blr->lock_pid,
 709                                         procid_self(),
 710                                         blr->offset,
 711                                         blr->count,
 712                                         blr->lock_flav);
 713                                 TALLOC_FREE(br_lck);
 714                         }
 715
 716                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 717                                 vuid ));
 718                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 719                         DLIST_REMOVE(blocking_lock_queue, blr);
 720                         free_blocking_lock_record(blr);
 721                         continue;
 722                 }
 723
 724                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 725                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 726
 727                         /*
 728                          * Remove the entry and return an error to the client.
 729                          */
 730
 731                         if (br_lck) {
 732                                 brl_lock_cancel(br_lck,
 733                                         blr->lock_pid,
 734                                         procid_self(),
 735                                         blr->offset,
 736                                         blr->count,
 737                                         blr->lock_flav);
 738                                 TALLOC_FREE(br_lck);
 739                         }
 740
 741                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 742                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 743                         DLIST_REMOVE(blocking_lock_queue, blr);
 744                         free_blocking_lock_record(blr);
 745                         change_to_root_user();
 746                         continue;
 747                 }
 748
 749                 /*
 750                  * Go through the remaining locks and try and obtain them.
 751                  * The call returns True if all locks were obtained successfully
 752                  * and False if we still need to wait.
 753                  */
 754
 755                 if(blocking_lock_record_process(blr)) {
 756                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 757
 758                         if (br_lck) {
 759                                 brl_lock_cancel(br_lck,
 760                                         blr->lock_pid,
 761                                         procid_self(),
 762                                         blr->offset,
 763                                         blr->count,
 764                                         blr->lock_flav);
 765                                 TALLOC_FREE(br_lck);
 766                         }
 767
 768                         DLIST_REMOVE(blocking_lock_queue, blr);
 769                         free_blocking_lock_record(blr);
 770                 }
 771                 change_to_root_user();
 772         }
 773 }
 774
 775 /****************************************************************************
 776  Handle a cancel message. Lock already moved onto the cancel queue.
 777 *****************************************************************************/
 778
 779 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 780
 781 static void process_blocking_lock_cancel_message(int msg_type,
 782                                                  struct process_id src,
 783                                                  void *buf, size_t len,
 784                                                  void *private_data)
 785 {
 786         NTSTATUS err;
 787         const char *msg = (const char *)buf;
 788         blocking_lock_record *blr;
 789
 790         if (buf == NULL) {
 791                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 792         }
 793
 794         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 795                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 796                         "Got invalid msg len %d\n", (int)len));
 797                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 798         }
 799
 800         memcpy(&blr, msg, sizeof(blr));
 801         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 802
 803         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 804                 nt_errstr(err) ));
 805
 806         blocking_lock_reply_error(blr, err);
 807         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 808         free_blocking_lock_record(blr);
 809 }
 810
 811 /****************************************************************************
 812  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 813 *****************************************************************************/
 814
 815 BOOL blocking_lock_cancel(files_struct *fsp,
 816                         uint32 lock_pid,
 817                         SMB_BIG_UINT offset,
 818                         SMB_BIG_UINT count,
 819                         enum brl_flavour lock_flav,
 820                         unsigned char locktype,
 821                         NTSTATUS err)
 822 {
 823         static BOOL initialized;
 824         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 825         blocking_lock_record *blr;
 826
 827         if (!initialized) {
 828                 /* Register our message. */
 829                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 830                                  process_blocking_lock_cancel_message,
 831                                  NULL);
 832
 833                 initialized = True;
 834         }
 835
 836         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 837                 if (fsp == blr->fsp &&
 838                                 lock_pid == blr->lock_pid &&
 839                                 offset == blr->offset &&
 840                                 count == blr->count &&
 841                                 lock_flav == blr->lock_flav) {
 842                         break;
 843                 }
 844         }
 845
 846         if (!blr) {
 847                 return False;
 848         }
 849
 850         /* Check the flags are right. */
 851         if (blr->com_type == SMBlockingX &&
 852                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 853                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 854                 return False;
 855         }
 856
 857         /* Move to cancelled queue. */
 858         DLIST_REMOVE(blocking_lock_queue, blr);
 859         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 860
 861         /* Create the message. */
 862         memcpy(msg, &blr, sizeof(blr));
 863         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 864
 865         message_send_pid(pid_to_procid(sys_getpid()),
 866                         MSG_SMB_BLOCKING_LOCK_CANCEL,
 867                         &msg, sizeof(msg), True);
 868
 869         return True;
 870 }