source/smbd/blocking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Blocking Locking functions
   4    Copyright (C) Jeremy Allison 1998-2003
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22 #undef DBGC_CLASS
  23 #define DBGC_CLASS DBGC_LOCKING
  24
  25 extern int max_send;
  26
  27 /****************************************************************************
  28  This is the structure to queue to implement blocking locks.
  29  notify. It consists of the requesting SMB and the expiry time.
  30 *****************************************************************************/
  31
  32 typedef struct _blocking_lock_record {
  33         struct _blocking_lock_record *next;
  34         struct _blocking_lock_record *prev;
  35         int com_type;
  36         files_struct *fsp;
  37         struct timeval expire_time;
  38         int lock_num;
  39         SMB_BIG_UINT offset;
  40         SMB_BIG_UINT count;
  41         uint32 lock_pid;
  42         uint32 blocking_pid; /* PID that blocks us. */
  43         enum brl_flavour lock_flav;
  44         enum brl_type lock_type;
  45         char *inbuf;
  46         int length;
  47 } blocking_lock_record;
  48
  49 /* dlink list we store pending lock records on. */
  50 static blocking_lock_record *blocking_lock_queue;
  51
  52 /* dlink list we move cancelled lock records onto. */
  53 static blocking_lock_record *blocking_lock_cancelled_queue;
  54
  55 /* The event that makes us process our blocking lock queue */
  56 static struct timed_event *brl_timeout;
  57
  58 /****************************************************************************
  59  Destructor for the above structure.
  60 ****************************************************************************/
  61
  62 static void free_blocking_lock_record(blocking_lock_record *blr)
  63 {
  64         SAFE_FREE(blr->inbuf);
  65         SAFE_FREE(blr);
  66 }
  67
  68 /****************************************************************************
  69  Determine if this is a secondary element of a chained SMB.
  70   **************************************************************************/
  71
  72 static BOOL in_chained_smb(void)
  73 {
  74         return (chain_size != 0);
  75 }
  76
  77 static void received_unlock_msg(struct messaging_context *msg,
  78                                 void *private_data,
  79                                 uint32_t msg_type,
  80                                 struct server_id server_id,
  81                                 DATA_BLOB *data);
  82 static void process_blocking_lock_queue(void);
  83
  84 static void brl_timeout_fn(struct event_context *event_ctx,
  85                            struct timed_event *te,
  86                            const struct timeval *now,
  87                            void *private_data)
  88 {
  89         SMB_ASSERT(brl_timeout == te);
  90         TALLOC_FREE(brl_timeout);
  91
  92         change_to_root_user();  /* TODO: Possibly run all timed events as
  93                                  * root */
  94
  95         process_blocking_lock_queue();
  96 }
  97
  98 /****************************************************************************
  99  After a change to blocking_lock_queue, recalculate the timed_event for the
 100  next processing.
 101 ****************************************************************************/
 102
 103 static BOOL recalc_brl_timeout(void)
 104 {
 105         blocking_lock_record *brl;
 106         struct timeval next_timeout;
 107
 108         TALLOC_FREE(brl_timeout);
 109
 110         next_timeout = timeval_zero();
 111
 112         for (brl = blocking_lock_queue; brl; brl = brl->next) {
 113                 if (timeval_is_zero(&brl->expire_time)) {
 114                         /*
 115                          * If we're blocked on pid 0xFFFFFFFF this is
 116                          * a POSIX lock, so calculate a timeout of
 117                          * 10 seconds into the future.
 118                          */
 119                         if (brl->blocking_pid == 0xFFFFFFFF) {
 120                                 struct timeval psx_to = timeval_current_ofs(10, 0);
 121                                 next_timeout = timeval_min(&next_timeout, &psx_to);
 122                         }
 123
 124                         continue;
 125                 }
 126
 127                 if (timeval_is_zero(&next_timeout)) {
 128                         next_timeout = brl->expire_time;
 129                 }
 130                 else {
 131                         next_timeout = timeval_min(&next_timeout,
 132                                                    &brl->expire_time);
 133                 }
 134         }
 135
 136         if (timeval_is_zero(&next_timeout)) {
 137                 return True;
 138         }
 139
 140         if (!(brl_timeout = event_add_timed(smbd_event_context(), NULL,
 141                                             next_timeout, "brl_timeout",
 142                                             brl_timeout_fn, NULL))) {
 143                 return False;
 144         }
 145
 146         return True;
 147 }
 148
 149
 150 /****************************************************************************
 151  Function to push a blocking lock request onto the lock queue.
 152 ****************************************************************************/
 153
 154 BOOL push_blocking_lock_request( struct byte_range_lock *br_lck,
 155                 char *inbuf, int length,
 156                 files_struct *fsp,
 157                 int lock_timeout,
 158                 int lock_num,
 159                 uint32 lock_pid,
 160                 enum brl_type lock_type,
 161                 enum brl_flavour lock_flav,
 162                 SMB_BIG_UINT offset,
 163                 SMB_BIG_UINT count,
 164                 uint32 blocking_pid)
 165 {
 166         static BOOL set_lock_msg;
 167         blocking_lock_record *blr;
 168         NTSTATUS status;
 169
 170         if(in_chained_smb() ) {
 171                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 172                 return False;
 173         }
 174
 175         /*
 176          * Now queue an entry on the blocking lock queue. We setup
 177          * the expiration time here.
 178          */
 179
 180         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 181                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 182                 return False;
 183         }
 184
 185         blr->next = NULL;
 186         blr->prev = NULL;
 187
 188         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 189                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 190                 SAFE_FREE(blr);
 191                 return False;
 192         }
 193
 194         blr->com_type = CVAL(inbuf,smb_com);
 195         blr->fsp = fsp;
 196         if (lock_timeout == -1) {
 197                 blr->expire_time.tv_sec = 0;
 198                 blr->expire_time.tv_usec = 0; /* Never expire. */
 199         } else {
 200                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 201                                         (lock_timeout % 1000) * 1000);
 202         }
 203         blr->lock_num = lock_num;
 204         blr->lock_pid = lock_pid;
 205         blr->blocking_pid = blocking_pid;
 206         blr->lock_flav = lock_flav;
 207         blr->lock_type = lock_type;
 208         blr->offset = offset;
 209         blr->count = count;
 210         memcpy(blr->inbuf, inbuf, length);
 211         blr->length = length;
 212
 213         /* Add a pending lock record for this. */
 214         status = brl_lock(smbd_messaging_context(), br_lck,
 215                         lock_pid,
 216                         procid_self(),
 217                         offset,
 218                         count,
 219                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 220                         blr->lock_flav,
 221                         lock_timeout ? True : False, /* blocking_lock. */
 222                         NULL);
 223
 224         if (!NT_STATUS_IS_OK(status)) {
 225                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 226                 DLIST_REMOVE(blocking_lock_queue, blr);
 227                 free_blocking_lock_record(blr);
 228                 return False;
 229         }
 230
 231         DLIST_ADD_END(blocking_lock_queue, blr, blocking_lock_record *);
 232         recalc_brl_timeout();
 233
 234         /* Ensure we'll receive messages when this is unlocked. */
 235         if (!set_lock_msg) {
 236                 messaging_register(smbd_messaging_context(), NULL,
 237                                    MSG_SMB_UNLOCK, received_unlock_msg);
 238                 set_lock_msg = True;
 239         }
 240
 241         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
 242                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 243                 length, (unsigned int)blr->expire_time.tv_sec,
 244                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 245                 blr->fsp->fnum, blr->fsp->fsp_name ));
 246
 247         /* Push the MID of this packet on the signing queue. */
 248         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 249
 250         return True;
 251 }
 252
 253 /****************************************************************************
 254  Return a smd with a given size.
 255 *****************************************************************************/
 256
 257 static void send_blocking_reply(char *outbuf, int outsize, const char *inbuf)
 258 {
 259         if(outsize > 4) {
 260                 smb_setlen(inbuf, outbuf,outsize - 4);
 261         }
 262
 263         if (!send_smb(smbd_server_fd(),outbuf)) {
 264                 exit_server_cleanly("send_blocking_reply: send_smb failed.");
 265         }
 266 }
 267
 268 /****************************************************************************
 269  Return a lockingX success SMB.
 270 *****************************************************************************/
 271
 272 static void reply_lockingX_success(blocking_lock_record *blr)
 273 {
 274         char *outbuf = get_OutBuffer();
 275         int bufsize = BUFFER_SIZE;
 276         char *inbuf = blr->inbuf;
 277         int outsize = 0;
 278
 279         construct_reply_common(inbuf, outbuf);
 280         set_message(inbuf,outbuf,2,0,True);
 281
 282         /*
 283          * As this message is a lockingX call we must handle
 284          * any following chained message correctly.
 285          * This is normally handled in construct_reply(),
 286          * but as that calls switch_message, we can't use
 287          * that here and must set up the chain info manually.
 288          */
 289
 290         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 291
 292         outsize += chain_size;
 293
 294         send_blocking_reply(outbuf,outsize,inbuf);
 295 }
 296
 297 /****************************************************************************
 298  Return a generic lock fail error blocking call.
 299 *****************************************************************************/
 300
 301 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 302 {
 303         char *outbuf = get_OutBuffer();
 304         char *inbuf = blr->inbuf;
 305         construct_reply_common(inbuf, outbuf);
 306
 307         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 308            FILE_LOCK_CONFLICT! (tridge) */
 309         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 310                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 311         }
 312
 313         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 314                 /* Store the last lock error. */
 315                 files_struct *fsp = blr->fsp;
 316
 317                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 318                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 319                 fsp->last_lock_failure.context.pid = procid_self();
 320                 fsp->last_lock_failure.start = blr->offset;
 321                 fsp->last_lock_failure.size = blr->count;
 322                 fsp->last_lock_failure.fnum = fsp->fnum;
 323                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 324                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 325         }
 326
 327         ERROR_NT(status);
 328         if (!send_smb(smbd_server_fd(),outbuf)) {
 329                 exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
 330         }
 331 }
 332
 333 /****************************************************************************
 334  Return a lock fail error for a lockingX call. Undo all the locks we have
 335  obtained first.
 336 *****************************************************************************/
 337
 338 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 339 {
 340         char *inbuf = blr->inbuf;
 341         files_struct *fsp = blr->fsp;
 342         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 343         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 344         uint32 lock_pid;
 345         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 346         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 347         char *data;
 348         int i;
 349
 350         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 351
 352         /*
 353          * Data now points at the beginning of the list
 354          * of smb_lkrng structs.
 355          */
 356
 357         /*
 358          * Ensure we don't do a remove on the lock that just failed,
 359          * as under POSIX rules, if we have a lock already there, we
 360          * will delete it (and we shouldn't) .....
 361          */
 362
 363         for(i = blr->lock_num - 1; i >= 0; i--) {
 364                 BOOL err;
 365
 366                 lock_pid = get_lock_pid( data, i, large_file_format);
 367                 count = get_lock_count( data, i, large_file_format);
 368                 offset = get_lock_offset( data, i, 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
 375                 do_unlock(smbd_messaging_context(),
 376                         fsp,
 377                         lock_pid,
 378                         count,
 379                         offset,
 380                         WINDOWS_LOCK);
 381         }
 382
 383         generic_blocking_lock_error(blr, status);
 384 }
 385
 386 /****************************************************************************
 387  Return a lock fail error.
 388 *****************************************************************************/
 389
 390 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 391 {
 392         switch(blr->com_type) {
 393         case SMBlockingX:
 394                 reply_lockingX_error(blr, status);
 395                 break;
 396         case SMBtrans2:
 397         case SMBtranss2:
 398                 {
 399                         char *outbuf = get_OutBuffer();
 400                         char *inbuf = blr->inbuf;
 401                         construct_reply_common(inbuf, outbuf);
 402                         /* construct_reply_common has done us the favor to pre-fill the
 403                          * command field with SMBtranss2 which is wrong :-)
 404                          */
 405                         SCVAL(outbuf,smb_com,SMBtrans2);
 406                         ERROR_NT(status);
 407                         if (!send_smb(smbd_server_fd(),outbuf)) {
 408                                 exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
 409                         }
 410                         break;
 411                 }
 412         default:
 413                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 414                 exit_server("PANIC - unknown type on blocking lock queue");
 415         }
 416 }
 417
 418 /****************************************************************************
 419  Attempt to finish off getting all pending blocking locks for a lockingX call.
 420  Returns True if we want to be removed from the list.
 421 *****************************************************************************/
 422
 423 static BOOL process_lockingX(blocking_lock_record *blr)
 424 {
 425         char *inbuf = blr->inbuf;
 426         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 427         files_struct *fsp = blr->fsp;
 428         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 429         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 430         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 431         uint32 lock_pid;
 432         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 433         char *data;
 434         NTSTATUS status = NT_STATUS_OK;
 435
 436         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 437
 438         /*
 439          * Data now points at the beginning of the list
 440          * of smb_lkrng structs.
 441          */
 442
 443         for(; blr->lock_num < num_locks; blr->lock_num++) {
 444                 struct byte_range_lock *br_lck = NULL;
 445                 BOOL err;
 446
 447                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 448                 count = get_lock_count( data, blr->lock_num, large_file_format);
 449                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 450
 451                 /*
 452                  * We know err cannot be set as if it was the lock
 453                  * request would never have been queued. JRA.
 454                  */
 455                 errno = 0;
 456                 br_lck = do_lock(smbd_messaging_context(),
 457                                 fsp,
 458                                 lock_pid,
 459                                 count,
 460                                 offset,
 461                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 462                                         READ_LOCK : WRITE_LOCK),
 463                                 WINDOWS_LOCK,
 464                                 True,
 465                                 &status,
 466                                 &blr->blocking_pid);
 467
 468                 TALLOC_FREE(br_lck);
 469
 470                 if (NT_STATUS_IS_ERR(status)) {
 471                         break;
 472                 }
 473         }
 474
 475         if(blr->lock_num == num_locks) {
 476                 /*
 477                  * Success - we got all the locks.
 478                  */
 479
 480                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 481                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 482
 483                 reply_lockingX_success(blr);
 484                 return True;
 485         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 486                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 487                         /*
 488                          * We have other than a "can't get lock"
 489                          * error. Free any locks we had and return an error.
 490                          * Return True so we get dequeued.
 491                          */
 492
 493                 blocking_lock_reply_error(blr, status);
 494                 return True;
 495         }
 496
 497         /*
 498          * Still can't get all the locks - keep waiting.
 499          */
 500
 501         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 502 Waiting....\n",
 503                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 504
 505         return False;
 506 }
 507
 508 /****************************************************************************
 509  Attempt to get the posix lock request from a SMBtrans2 call.
 510  Returns True if we want to be removed from the list.
 511 *****************************************************************************/
 512
 513 static BOOL process_trans2(blocking_lock_record *blr)
 514 {
 515         char *inbuf = blr->inbuf;
 516         char *outbuf;
 517         char params[2];
 518         NTSTATUS status;
 519         struct byte_range_lock *br_lck = do_lock(smbd_messaging_context(),
 520                                                 blr->fsp,
 521                                                 blr->lock_pid,
 522                                                 blr->count,
 523                                                 blr->offset,
 524                                                 blr->lock_type,
 525                                                 blr->lock_flav,
 526                                                 True,
 527                                                 &status,
 528                                                 &blr->blocking_pid);
 529         TALLOC_FREE(br_lck);
 530
 531         if (!NT_STATUS_IS_OK(status)) {
 532                 if (ERROR_WAS_LOCK_DENIED(status)) {
 533                         /* Still can't get the lock, just keep waiting. */
 534                         return False;
 535                 }
 536                 /*
 537                  * We have other than a "can't get lock"
 538                  * error. Send an error and return True so we get dequeued.
 539                  */
 540                 blocking_lock_reply_error(blr, status);
 541                 return True;
 542         }
 543
 544         /* We finally got the lock, return success. */
 545         outbuf = get_OutBuffer();
 546         construct_reply_common(inbuf, outbuf);
 547         SCVAL(outbuf,smb_com,SMBtrans2);
 548         SSVAL(params,0,0);
 549         /* Fake up max_data_bytes here - we know it fits. */
 550         send_trans2_replies(inbuf, outbuf, max_send, params, 2, NULL, 0, 0xffff);
 551         return True;
 552 }
 553
 554
 555 /****************************************************************************
 556  Process a blocking lock SMB.
 557  Returns True if we want to be removed from the list.
 558 *****************************************************************************/
 559
 560 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 561 {
 562         switch(blr->com_type) {
 563                 case SMBlockingX:
 564                         return process_lockingX(blr);
 565                 case SMBtrans2:
 566                 case SMBtranss2:
 567                         return process_trans2(blr);
 568                 default:
 569                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 570                         exit_server("PANIC - unknown type on blocking lock queue");
 571         }
 572         return False; /* Keep compiler happy. */
 573 }
 574
 575 /****************************************************************************
 576  Cancel entries by fnum from the blocking lock pending queue.
 577 *****************************************************************************/
 578
 579 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 580 {
 581         blocking_lock_record *blr, *next = NULL;
 582
 583         for(blr = blocking_lock_queue; blr; blr = next) {
 584                 next = blr->next;
 585                 if(blr->fsp->fnum == fsp->fnum) {
 586                         unsigned char locktype = 0;
 587
 588                         if (blr->com_type == SMBlockingX) {
 589                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 590                         }
 591
 592                         if (br_lck) {
 593                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 594 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 595
 596                                 brl_lock_cancel(br_lck,
 597                                         blr->lock_pid,
 598                                         procid_self(),
 599                                         blr->offset,
 600                                         blr->count,
 601                                         blr->lock_flav);
 602
 603                                 blocking_lock_cancel(fsp,
 604                                         blr->lock_pid,
 605                                         blr->offset,
 606                                         blr->count,
 607                                         blr->lock_flav,
 608                                         locktype,
 609                                         NT_STATUS_RANGE_NOT_LOCKED);
 610                         }
 611                 }
 612         }
 613 }
 614
 615 /****************************************************************************
 616  Delete entries by mid from the blocking lock pending queue. Always send reply.
 617 *****************************************************************************/
 618
 619 void remove_pending_lock_requests_by_mid(int mid)
 620 {
 621         blocking_lock_record *blr, *next = NULL;
 622
 623         for(blr = blocking_lock_queue; blr; blr = next) {
 624                 next = blr->next;
 625                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 626                         files_struct *fsp = blr->fsp;
 627                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 628
 629                         if (br_lck) {
 630                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 631 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 632
 633                                 brl_lock_cancel(br_lck,
 634                                         blr->lock_pid,
 635                                         procid_self(),
 636                                         blr->offset,
 637                                         blr->count,
 638                                         blr->lock_flav);
 639                                 TALLOC_FREE(br_lck);
 640                         }
 641
 642                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 643                         DLIST_REMOVE(blocking_lock_queue, blr);
 644                         free_blocking_lock_record(blr);
 645                 }
 646         }
 647 }
 648
 649 /****************************************************************************
 650  Is this mid a blocking lock request on the queue ?
 651 *****************************************************************************/
 652
 653 BOOL blocking_lock_was_deferred(int mid)
 654 {
 655         blocking_lock_record *blr, *next = NULL;
 656
 657         for(blr = blocking_lock_queue; blr; blr = next) {
 658                 next = blr->next;
 659                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 660                         return True;
 661                 }
 662         }
 663         return False;
 664 }
 665
 666 /****************************************************************************
 667   Set a flag as an unlock request affects one of our pending locks.
 668 *****************************************************************************/
 669
 670 static void received_unlock_msg(struct messaging_context *msg,
 671                                 void *private_data,
 672                                 uint32_t msg_type,
 673                                 struct server_id server_id,
 674                                 DATA_BLOB *data)
 675 {
 676         DEBUG(10,("received_unlock_msg\n"));
 677         process_blocking_lock_queue();
 678 }
 679
 680 /****************************************************************************
 681  Process the blocking lock queue. Note that this is only called as root.
 682 *****************************************************************************/
 683
 684 static void process_blocking_lock_queue(void)
 685 {
 686         struct timeval tv_curr = timeval_current();
 687         blocking_lock_record *blr, *next = NULL;
 688         BOOL recalc_timeout = False;
 689
 690         /*
 691          * Go through the queue and see if we can get any of the locks.
 692          */
 693
 694         for (blr = blocking_lock_queue; blr; blr = next) {
 695                 connection_struct *conn = NULL;
 696                 uint16 vuid;
 697                 files_struct *fsp = NULL;
 698
 699                 next = blr->next;
 700
 701                 /*
 702                  * Ensure we don't have any old chain_fsp values
 703                  * sitting around....
 704                  */
 705                 chain_size = 0;
 706                 file_chain_reset();
 707                 fsp = blr->fsp;
 708
 709                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 710                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 711                                 SVAL(blr->inbuf,smb_uid);
 712
 713                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 714                         fsp->fnum, fsp->fsp_name ));
 715
 716                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 717                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 718
 719                         /*
 720                          * Lock expired - throw away all previously
 721                          * obtained locks and return lock error.
 722                          */
 723
 724                         if (br_lck) {
 725                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 726                                         fsp->fnum, fsp->fsp_name ));
 727
 728                                 brl_lock_cancel(br_lck,
 729                                         blr->lock_pid,
 730                                         procid_self(),
 731                                         blr->offset,
 732                                         blr->count,
 733                                         blr->lock_flav);
 734                                 TALLOC_FREE(br_lck);
 735                         }
 736
 737                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 738                         DLIST_REMOVE(blocking_lock_queue, blr);
 739                         free_blocking_lock_record(blr);
 740                         recalc_timeout = True;
 741                         continue;
 742                 }
 743
 744                 if(!change_to_user(conn,vuid)) {
 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 user vuid=%d.\n",
 762                                 vuid ));
 763                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 764                         DLIST_REMOVE(blocking_lock_queue, blr);
 765                         free_blocking_lock_record(blr);
 766                         recalc_timeout = True;
 767                         continue;
 768                 }
 769
 770                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 771                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 772
 773                         /*
 774                          * Remove the entry and return an error to the client.
 775                          */
 776
 777                         if (br_lck) {
 778                                 brl_lock_cancel(br_lck,
 779                                         blr->lock_pid,
 780                                         procid_self(),
 781                                         blr->offset,
 782                                         blr->count,
 783                                         blr->lock_flav);
 784                                 TALLOC_FREE(br_lck);
 785                         }
 786
 787                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 788                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 789                         DLIST_REMOVE(blocking_lock_queue, blr);
 790                         free_blocking_lock_record(blr);
 791                         recalc_timeout = True;
 792                         change_to_root_user();
 793                         continue;
 794                 }
 795
 796                 /*
 797                  * Go through the remaining locks and try and obtain them.
 798                  * The call returns True if all locks were obtained successfully
 799                  * and False if we still need to wait.
 800                  */
 801
 802                 if(blocking_lock_record_process(blr)) {
 803                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 804
 805                         if (br_lck) {
 806                                 brl_lock_cancel(br_lck,
 807                                         blr->lock_pid,
 808                                         procid_self(),
 809                                         blr->offset,
 810                                         blr->count,
 811                                         blr->lock_flav);
 812                                 TALLOC_FREE(br_lck);
 813                         }
 814
 815                         DLIST_REMOVE(blocking_lock_queue, blr);
 816                         free_blocking_lock_record(blr);
 817                         recalc_timeout = True;
 818                 }
 819                 change_to_root_user();
 820         }
 821
 822         if (recalc_timeout) {
 823                 recalc_brl_timeout();
 824         }
 825 }
 826
 827 /****************************************************************************
 828  Handle a cancel message. Lock already moved onto the cancel queue.
 829 *****************************************************************************/
 830
 831 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 832
 833 static void process_blocking_lock_cancel_message(struct messaging_context *ctx,
 834                                                  void *private_data,
 835                                                  uint32_t msg_type,
 836                                                  struct server_id server_id,
 837                                                  DATA_BLOB *data)
 838 {
 839         NTSTATUS err;
 840         const char *msg = (const char *)data->data;
 841         blocking_lock_record *blr;
 842
 843         if (data->data == NULL) {
 844                 smb_panic("process_blocking_lock_cancel_message: null msg");
 845         }
 846
 847         if (data->length != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 848                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 849                           "Got invalid msg len %d\n", (int)data->length));
 850                 smb_panic("process_blocking_lock_cancel_message: bad msg");
 851         }
 852
 853         memcpy(&blr, msg, sizeof(blr));
 854         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 855
 856         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 857                 nt_errstr(err) ));
 858
 859         blocking_lock_reply_error(blr, err);
 860         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 861         free_blocking_lock_record(blr);
 862 }
 863
 864 /****************************************************************************
 865  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 866 *****************************************************************************/
 867
 868 BOOL blocking_lock_cancel(files_struct *fsp,
 869                         uint32 lock_pid,
 870                         SMB_BIG_UINT offset,
 871                         SMB_BIG_UINT count,
 872                         enum brl_flavour lock_flav,
 873                         unsigned char locktype,
 874                         NTSTATUS err)
 875 {
 876         static BOOL initialized;
 877         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 878         blocking_lock_record *blr;
 879
 880         if (!initialized) {
 881                 /* Register our message. */
 882                 messaging_register(smbd_messaging_context(), NULL,
 883                                    MSG_SMB_BLOCKING_LOCK_CANCEL,
 884                                    process_blocking_lock_cancel_message);
 885
 886                 initialized = True;
 887         }
 888
 889         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 890                 if (fsp == blr->fsp &&
 891                                 lock_pid == blr->lock_pid &&
 892                                 offset == blr->offset &&
 893                                 count == blr->count &&
 894                                 lock_flav == blr->lock_flav) {
 895                         break;
 896                 }
 897         }
 898
 899         if (!blr) {
 900                 return False;
 901         }
 902
 903         /* Check the flags are right. */
 904         if (blr->com_type == SMBlockingX &&
 905                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 906                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 907                 return False;
 908         }
 909
 910         /* Move to cancelled queue. */
 911         DLIST_REMOVE(blocking_lock_queue, blr);
 912         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 913
 914         /* Create the message. */
 915         memcpy(msg, &blr, sizeof(blr));
 916         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 917
 918         messaging_send_buf(smbd_messaging_context(), procid_self(),
 919                            MSG_SMB_BLOCKING_LOCK_CANCEL,
 920                            (uint8 *)&msg, sizeof(msg));
 921
 922         return True;
 923 }