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 3 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, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #undef DBGC_CLASS
  22 #define DBGC_CLASS DBGC_LOCKING
  23
  24 /****************************************************************************
  25  This is the structure to queue to implement blocking locks.
  26  notify. It consists of the requesting SMB and the expiry time.
  27 *****************************************************************************/
  28
  29 typedef struct _blocking_lock_record {
  30         struct _blocking_lock_record *next;
  31         struct _blocking_lock_record *prev;
  32         int com_type;
  33         files_struct *fsp;
  34         struct timeval expire_time;
  35         int lock_num;
  36         SMB_BIG_UINT offset;
  37         SMB_BIG_UINT count;
  38         uint32 lock_pid;
  39         uint32 blocking_pid; /* PID that blocks us. */
  40         enum brl_flavour lock_flav;
  41         enum brl_type lock_type;
  42         char *inbuf;
  43         int length;
  44         bool encrypted;
  45 } blocking_lock_record;
  46
  47 /* dlink list we store pending lock records on. */
  48 static blocking_lock_record *blocking_lock_queue;
  49
  50 /* dlink list we move cancelled lock records onto. */
  51 static blocking_lock_record *blocking_lock_cancelled_queue;
  52
  53 /* The event that makes us process our blocking lock queue */
  54 static struct timed_event *brl_timeout;
  55
  56 /****************************************************************************
  57  Destructor for the above structure.
  58 ****************************************************************************/
  59
  60 static void free_blocking_lock_record(blocking_lock_record *blr)
  61 {
  62         SAFE_FREE(blr->inbuf);
  63         SAFE_FREE(blr);
  64 }
  65
  66 /****************************************************************************
  67  Determine if this is a secondary element of a chained SMB.
  68   **************************************************************************/
  69
  70 static bool in_chained_smb(void)
  71 {
  72         return (chain_size != 0);
  73 }
  74
  75 static void received_unlock_msg(struct messaging_context *msg,
  76                                 void *private_data,
  77                                 uint32_t msg_type,
  78                                 struct server_id server_id,
  79                                 DATA_BLOB *data);
  80 static void process_blocking_lock_queue(void);
  81
  82 static void brl_timeout_fn(struct event_context *event_ctx,
  83                            struct timed_event *te,
  84                            const struct timeval *now,
  85                            void *private_data)
  86 {
  87         SMB_ASSERT(brl_timeout == te);
  88         TALLOC_FREE(brl_timeout);
  89
  90         change_to_root_user();  /* TODO: Possibly run all timed events as
  91                                  * root */
  92
  93         process_blocking_lock_queue();
  94 }
  95
  96 /****************************************************************************
  97  After a change to blocking_lock_queue, recalculate the timed_event for the
  98  next processing.
  99 ****************************************************************************/
 100
 101 static bool recalc_brl_timeout(void)
 102 {
 103         blocking_lock_record *brl;
 104         struct timeval next_timeout;
 105
 106         TALLOC_FREE(brl_timeout);
 107
 108         next_timeout = timeval_zero();
 109
 110         for (brl = blocking_lock_queue; brl; brl = brl->next) {
 111                 if (timeval_is_zero(&brl->expire_time)) {
 112                         /*
 113                          * If we're blocked on pid 0xFFFFFFFF this is
 114                          * a POSIX lock, so calculate a timeout of
 115                          * 10 seconds into the future.
 116                          */
 117                         if (brl->blocking_pid == 0xFFFFFFFF) {
 118                                 struct timeval psx_to = timeval_current_ofs(10, 0);
 119                                 next_timeout = timeval_min(&next_timeout, &psx_to);
 120                         }
 121
 122                         continue;
 123                 }
 124
 125                 if (timeval_is_zero(&next_timeout)) {
 126                         next_timeout = brl->expire_time;
 127                 }
 128                 else {
 129                         next_timeout = timeval_min(&next_timeout,
 130                                                    &brl->expire_time);
 131                 }
 132         }
 133
 134         if (timeval_is_zero(&next_timeout)) {
 135                 return True;
 136         }
 137
 138         if (!(brl_timeout = event_add_timed(smbd_event_context(), NULL,
 139                                             next_timeout, "brl_timeout",
 140                                             brl_timeout_fn, NULL))) {
 141                 return False;
 142         }
 143
 144         return True;
 145 }
 146
 147
 148 /****************************************************************************
 149  Function to push a blocking lock request onto the lock queue.
 150 ****************************************************************************/
 151
 152 bool push_blocking_lock_request( struct byte_range_lock *br_lck,
 153                 const struct smb_request *req,
 154                 files_struct *fsp,
 155                 int lock_timeout,
 156                 int lock_num,
 157                 uint32 lock_pid,
 158                 enum brl_type lock_type,
 159                 enum brl_flavour lock_flav,
 160                 SMB_BIG_UINT offset,
 161                 SMB_BIG_UINT count,
 162                 uint32 blocking_pid)
 163 {
 164         static bool set_lock_msg;
 165         size_t length = smb_len(req->inbuf)+4;
 166         blocking_lock_record *blr;
 167         NTSTATUS status;
 168
 169         if(in_chained_smb() ) {
 170                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 171                 return False;
 172         }
 173
 174         /*
 175          * Now queue an entry on the blocking lock queue. We setup
 176          * the expiration time here.
 177          */
 178
 179         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 180                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 181                 return False;
 182         }
 183
 184         blr->next = NULL;
 185         blr->prev = NULL;
 186
 187         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 188                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 189                 SAFE_FREE(blr);
 190                 return False;
 191         }
 192
 193         blr->com_type = CVAL(req->inbuf,smb_com);
 194         blr->fsp = fsp;
 195         if (lock_timeout == -1) {
 196                 blr->expire_time.tv_sec = 0;
 197                 blr->expire_time.tv_usec = 0; /* Never expire. */
 198         } else {
 199                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 200                                         (lock_timeout % 1000) * 1000);
 201         }
 202         blr->lock_num = lock_num;
 203         blr->lock_pid = lock_pid;
 204         blr->blocking_pid = blocking_pid;
 205         blr->lock_flav = lock_flav;
 206         blr->lock_type = lock_type;
 207         blr->offset = offset;
 208         blr->count = count;
 209         memcpy(blr->inbuf, req->inbuf, length);
 210         blr->length = length;
 211         blr->encrypted = req->encrypted;
 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(req->inbuf,smb_mid));
 249
 250         return True;
 251 }
 252
 253 /****************************************************************************
 254  Return a lockingX success SMB.
 255 *****************************************************************************/
 256
 257 static void reply_lockingX_success(blocking_lock_record *blr)
 258 {
 259         struct smb_request *req;
 260
 261         if (!(req = talloc(talloc_tos(), struct smb_request))) {
 262                 smb_panic("Could not allocate smb_request");
 263         }
 264
 265         init_smb_request(req, (uint8 *)blr->inbuf, 0, blr->encrypted);
 266         reply_outbuf(req, 2, 0);
 267
 268         /*
 269          * As this message is a lockingX call we must handle
 270          * any following chained message correctly.
 271          * This is normally handled in construct_reply(),
 272          * but as that calls switch_message, we can't use
 273          * that here and must set up the chain info manually.
 274          */
 275
 276         chain_reply(req);
 277
 278         if (!srv_send_smb(smbd_server_fd(),
 279                         (char *)req->outbuf,
 280                         IS_CONN_ENCRYPTED(blr->fsp->conn))) {
 281                 exit_server_cleanly("send_blocking_reply: srv_send_smb failed.");
 282         }
 283 }
 284
 285 /****************************************************************************
 286  Return a generic lock fail error blocking call.
 287 *****************************************************************************/
 288
 289 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 290 {
 291         char outbuf[smb_size];
 292         char *inbuf = blr->inbuf;
 293
 294         construct_reply_common(inbuf, outbuf);
 295
 296         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 297            FILE_LOCK_CONFLICT! (tridge) */
 298         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 299                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 300         }
 301
 302         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 303                 /* Store the last lock error. */
 304                 files_struct *fsp = blr->fsp;
 305
 306                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 307                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 308                 fsp->last_lock_failure.context.pid = procid_self();
 309                 fsp->last_lock_failure.start = blr->offset;
 310                 fsp->last_lock_failure.size = blr->count;
 311                 fsp->last_lock_failure.fnum = fsp->fnum;
 312                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 313                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 314         }
 315
 316         ERROR_NT(status);
 317         if (!srv_send_smb(smbd_server_fd(),outbuf,
 318                         IS_CONN_ENCRYPTED(blr->fsp->conn))) {
 319                 exit_server_cleanly("generic_blocking_lock_error: srv_send_smb failed.");
 320         }
 321 }
 322
 323 /****************************************************************************
 324  Return a lock fail error for a lockingX call. Undo all the locks we have
 325  obtained first.
 326 *****************************************************************************/
 327
 328 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 329 {
 330         char *inbuf = blr->inbuf;
 331         files_struct *fsp = blr->fsp;
 332         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 333         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 334         uint32 lock_pid;
 335         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 336         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 337         char *data;
 338         int i;
 339
 340         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 341
 342         /*
 343          * Data now points at the beginning of the list
 344          * of smb_lkrng structs.
 345          */
 346
 347         /*
 348          * Ensure we don't do a remove on the lock that just failed,
 349          * as under POSIX rules, if we have a lock already there, we
 350          * will delete it (and we shouldn't) .....
 351          */
 352
 353         for(i = blr->lock_num - 1; i >= 0; i--) {
 354                 bool err;
 355
 356                 lock_pid = get_lock_pid( data, i, large_file_format);
 357                 count = get_lock_count( data, i, large_file_format);
 358                 offset = get_lock_offset( data, i, large_file_format, &err);
 359
 360                 /*
 361                  * We know err cannot be set as if it was the lock
 362                  * request would never have been queued. JRA.
 363                  */
 364
 365                 do_unlock(smbd_messaging_context(),
 366                         fsp,
 367                         lock_pid,
 368                         count,
 369                         offset,
 370                         WINDOWS_LOCK);
 371         }
 372
 373         generic_blocking_lock_error(blr, status);
 374 }
 375
 376 /****************************************************************************
 377  Return a lock fail error.
 378 *****************************************************************************/
 379
 380 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 381 {
 382         switch(blr->com_type) {
 383         case SMBlockingX:
 384                 reply_lockingX_error(blr, status);
 385                 break;
 386         case SMBtrans2:
 387         case SMBtranss2:
 388                 {
 389                         char outbuf[smb_size];
 390                         char *inbuf = blr->inbuf;
 391                         construct_reply_common(inbuf, outbuf);
 392                         /* construct_reply_common has done us the favor to pre-fill the
 393                          * command field with SMBtranss2 which is wrong :-)
 394                          */
 395                         SCVAL(outbuf,smb_com,SMBtrans2);
 396                         ERROR_NT(status);
 397                         if (!srv_send_smb(smbd_server_fd(),
 398                                         outbuf,
 399                                         IS_CONN_ENCRYPTED(blr->fsp->conn))) {
 400                                 exit_server_cleanly("blocking_lock_reply_error: srv_send_smb failed.");
 401                         }
 402                         break;
 403                 }
 404         default:
 405                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 406                 exit_server("PANIC - unknown type on blocking lock queue");
 407         }
 408 }
 409
 410 /****************************************************************************
 411  Attempt to finish off getting all pending blocking locks for a lockingX call.
 412  Returns True if we want to be removed from the list.
 413 *****************************************************************************/
 414
 415 static bool process_lockingX(blocking_lock_record *blr)
 416 {
 417         char *inbuf = blr->inbuf;
 418         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 419         files_struct *fsp = blr->fsp;
 420         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 421         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 422         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 423         uint32 lock_pid;
 424         bool large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 425         char *data;
 426         NTSTATUS status = NT_STATUS_OK;
 427
 428         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 429
 430         /*
 431          * Data now points at the beginning of the list
 432          * of smb_lkrng structs.
 433          */
 434
 435         for(; blr->lock_num < num_locks; blr->lock_num++) {
 436                 struct byte_range_lock *br_lck = NULL;
 437                 bool err;
 438
 439                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 440                 count = get_lock_count( data, blr->lock_num, large_file_format);
 441                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 442
 443                 /*
 444                  * We know err cannot be set as if it was the lock
 445                  * request would never have been queued. JRA.
 446                  */
 447                 errno = 0;
 448                 br_lck = do_lock(smbd_messaging_context(),
 449                                 fsp,
 450                                 lock_pid,
 451                                 count,
 452                                 offset,
 453                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 454                                         READ_LOCK : WRITE_LOCK),
 455                                 WINDOWS_LOCK,
 456                                 True,
 457                                 &status,
 458                                 &blr->blocking_pid);
 459
 460                 TALLOC_FREE(br_lck);
 461
 462                 if (NT_STATUS_IS_ERR(status)) {
 463                         break;
 464                 }
 465         }
 466
 467         if(blr->lock_num == num_locks) {
 468                 /*
 469                  * Success - we got all the locks.
 470                  */
 471
 472                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 473                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 474
 475                 reply_lockingX_success(blr);
 476                 return True;
 477         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 478                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 479                         /*
 480                          * We have other than a "can't get lock"
 481                          * error. Free any locks we had and return an error.
 482                          * Return True so we get dequeued.
 483                          */
 484
 485                 blocking_lock_reply_error(blr, status);
 486                 return True;
 487         }
 488
 489         /*
 490          * Still can't get all the locks - keep waiting.
 491          */
 492
 493         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 494 Waiting....\n",
 495                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 496
 497         return False;
 498 }
 499
 500 /****************************************************************************
 501  Attempt to get the posix lock request from a SMBtrans2 call.
 502  Returns True if we want to be removed from the list.
 503 *****************************************************************************/
 504
 505 static bool process_trans2(blocking_lock_record *blr)
 506 {
 507         struct smb_request *req;
 508         char params[2];
 509         NTSTATUS status;
 510         struct byte_range_lock *br_lck = do_lock(smbd_messaging_context(),
 511                                                 blr->fsp,
 512                                                 blr->lock_pid,
 513                                                 blr->count,
 514                                                 blr->offset,
 515                                                 blr->lock_type,
 516                                                 blr->lock_flav,
 517                                                 True,
 518                                                 &status,
 519                                                 &blr->blocking_pid);
 520         TALLOC_FREE(br_lck);
 521
 522         if (!NT_STATUS_IS_OK(status)) {
 523                 if (ERROR_WAS_LOCK_DENIED(status)) {
 524                         /* Still can't get the lock, just keep waiting. */
 525                         return False;
 526                 }
 527                 /*
 528                  * We have other than a "can't get lock"
 529                  * error. Send an error and return True so we get dequeued.
 530                  */
 531                 blocking_lock_reply_error(blr, status);
 532                 return True;
 533         }
 534
 535         /* We finally got the lock, return success. */
 536
 537         if (!(req = talloc(talloc_tos(), struct smb_request))) {
 538                 blocking_lock_reply_error(blr, NT_STATUS_NO_MEMORY);
 539                 return True;
 540         }
 541
 542         init_smb_request(req, (uint8 *)blr->inbuf, 0, blr->encrypted);
 543
 544         SCVAL(req->inbuf, smb_com, SMBtrans2);
 545         SSVAL(params,0,0);
 546         /* Fake up max_data_bytes here - we know it fits. */
 547         send_trans2_replies(blr->fsp->conn, req, params, 2, NULL, 0, 0xffff);
 548         return True;
 549 }
 550
 551
 552 /****************************************************************************
 553  Process a blocking lock SMB.
 554  Returns True if we want to be removed from the list.
 555 *****************************************************************************/
 556
 557 static bool blocking_lock_record_process(blocking_lock_record *blr)
 558 {
 559         switch(blr->com_type) {
 560                 case SMBlockingX:
 561                         return process_lockingX(blr);
 562                 case SMBtrans2:
 563                 case SMBtranss2:
 564                         return process_trans2(blr);
 565                 default:
 566                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 567                         exit_server("PANIC - unknown type on blocking lock queue");
 568         }
 569         return False; /* Keep compiler happy. */
 570 }
 571
 572 /****************************************************************************
 573  Cancel entries by fnum from the blocking lock pending queue.
 574 *****************************************************************************/
 575
 576 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 577 {
 578         blocking_lock_record *blr, *next = NULL;
 579
 580         for(blr = blocking_lock_queue; blr; blr = next) {
 581                 next = blr->next;
 582                 if(blr->fsp->fnum == fsp->fnum) {
 583                         unsigned char locktype = 0;
 584
 585                         if (blr->com_type == SMBlockingX) {
 586                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 587                         }
 588
 589                         if (br_lck) {
 590                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 591 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 592
 593                                 brl_lock_cancel(br_lck,
 594                                         blr->lock_pid,
 595                                         procid_self(),
 596                                         blr->offset,
 597                                         blr->count,
 598                                         blr->lock_flav);
 599
 600                                 blocking_lock_cancel(fsp,
 601                                         blr->lock_pid,
 602                                         blr->offset,
 603                                         blr->count,
 604                                         blr->lock_flav,
 605                                         locktype,
 606                                         NT_STATUS_RANGE_NOT_LOCKED);
 607                         }
 608                 }
 609         }
 610 }
 611
 612 /****************************************************************************
 613  Delete entries by mid from the blocking lock pending queue. Always send reply.
 614 *****************************************************************************/
 615
 616 void remove_pending_lock_requests_by_mid(int mid)
 617 {
 618         blocking_lock_record *blr, *next = NULL;
 619
 620         for(blr = blocking_lock_queue; blr; blr = next) {
 621                 next = blr->next;
 622                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 623                         files_struct *fsp = blr->fsp;
 624                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 625
 626                         if (br_lck) {
 627                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 628 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 629
 630                                 brl_lock_cancel(br_lck,
 631                                         blr->lock_pid,
 632                                         procid_self(),
 633                                         blr->offset,
 634                                         blr->count,
 635                                         blr->lock_flav);
 636                                 TALLOC_FREE(br_lck);
 637                         }
 638
 639                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 640                         DLIST_REMOVE(blocking_lock_queue, blr);
 641                         free_blocking_lock_record(blr);
 642                 }
 643         }
 644 }
 645
 646 /****************************************************************************
 647  Is this mid a blocking lock request on the queue ?
 648 *****************************************************************************/
 649
 650 bool blocking_lock_was_deferred(int mid)
 651 {
 652         blocking_lock_record *blr, *next = NULL;
 653
 654         for(blr = blocking_lock_queue; blr; blr = next) {
 655                 next = blr->next;
 656                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 657                         return True;
 658                 }
 659         }
 660         return False;
 661 }
 662
 663 /****************************************************************************
 664   Set a flag as an unlock request affects one of our pending locks.
 665 *****************************************************************************/
 666
 667 static void received_unlock_msg(struct messaging_context *msg,
 668                                 void *private_data,
 669                                 uint32_t msg_type,
 670                                 struct server_id server_id,
 671                                 DATA_BLOB *data)
 672 {
 673         DEBUG(10,("received_unlock_msg\n"));
 674         process_blocking_lock_queue();
 675 }
 676
 677 /****************************************************************************
 678  Process the blocking lock queue. Note that this is only called as root.
 679 *****************************************************************************/
 680
 681 static void process_blocking_lock_queue(void)
 682 {
 683         struct timeval tv_curr = timeval_current();
 684         blocking_lock_record *blr, *next = NULL;
 685         bool recalc_timeout = False;
 686
 687         /*
 688          * Go through the queue and see if we can get any of the locks.
 689          */
 690
 691         for (blr = blocking_lock_queue; blr; blr = next) {
 692                 connection_struct *conn = NULL;
 693                 uint16 vuid;
 694                 files_struct *fsp = NULL;
 695
 696                 next = blr->next;
 697
 698                 /*
 699                  * Ensure we don't have any old chain_fsp values
 700                  * sitting around....
 701                  */
 702                 chain_size = 0;
 703                 file_chain_reset();
 704                 fsp = blr->fsp;
 705
 706                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 707                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 708                                 SVAL(blr->inbuf,smb_uid);
 709
 710                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 711                         fsp->fnum, fsp->fsp_name ));
 712
 713                 if(!change_to_user(conn,vuid)) {
 714                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 715
 716                         /*
 717                          * Remove the entry and return an error to the client.
 718                          */
 719
 720                         if (br_lck) {
 721                                 brl_lock_cancel(br_lck,
 722                                         blr->lock_pid,
 723                                         procid_self(),
 724                                         blr->offset,
 725                                         blr->count,
 726                                         blr->lock_flav);
 727                                 TALLOC_FREE(br_lck);
 728                         }
 729
 730                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 731                                 vuid ));
 732                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 733                         DLIST_REMOVE(blocking_lock_queue, blr);
 734                         free_blocking_lock_record(blr);
 735                         recalc_timeout = True;
 736                         continue;
 737                 }
 738
 739                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 740                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 741
 742                         /*
 743                          * Remove the entry and return an error to the client.
 744                          */
 745
 746                         if (br_lck) {
 747                                 brl_lock_cancel(br_lck,
 748                                         blr->lock_pid,
 749                                         procid_self(),
 750                                         blr->offset,
 751                                         blr->count,
 752                                         blr->lock_flav);
 753                                 TALLOC_FREE(br_lck);
 754                         }
 755
 756                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 757                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 758                         DLIST_REMOVE(blocking_lock_queue, blr);
 759                         free_blocking_lock_record(blr);
 760                         recalc_timeout = True;
 761                         change_to_root_user();
 762                         continue;
 763                 }
 764
 765                 /*
 766                  * Go through the remaining locks and try and obtain them.
 767                  * The call returns True if all locks were obtained successfully
 768                  * and False if we still need to wait.
 769                  */
 770
 771                 if(blocking_lock_record_process(blr)) {
 772                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 773
 774                         if (br_lck) {
 775                                 brl_lock_cancel(br_lck,
 776                                         blr->lock_pid,
 777                                         procid_self(),
 778                                         blr->offset,
 779                                         blr->count,
 780                                         blr->lock_flav);
 781                                 TALLOC_FREE(br_lck);
 782                         }
 783
 784                         DLIST_REMOVE(blocking_lock_queue, blr);
 785                         free_blocking_lock_record(blr);
 786                         recalc_timeout = True;
 787                         change_to_root_user();
 788                         continue;
 789                 }
 790
 791                 change_to_root_user();
 792
 793                 /*
 794                  * We couldn't get the locks for this record on the list.
 795                  * If the time has expired, return a lock error.
 796                  */
 797
 798                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 799                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 800
 801                         /*
 802                          * Lock expired - throw away all previously
 803                          * obtained locks and return lock error.
 804                          */
 805
 806                         if (br_lck) {
 807                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 808                                         fsp->fnum, fsp->fsp_name ));
 809
 810                                 brl_lock_cancel(br_lck,
 811                                         blr->lock_pid,
 812                                         procid_self(),
 813                                         blr->offset,
 814                                         blr->count,
 815                                         blr->lock_flav);
 816                                 TALLOC_FREE(br_lck);
 817                         }
 818
 819                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 820                         DLIST_REMOVE(blocking_lock_queue, blr);
 821                         free_blocking_lock_record(blr);
 822                         recalc_timeout = True;
 823                 }
 824         }
 825
 826         if (recalc_timeout) {
 827                 recalc_brl_timeout();
 828         }
 829 }
 830
 831 /****************************************************************************
 832  Handle a cancel message. Lock already moved onto the cancel queue.
 833 *****************************************************************************/
 834
 835 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 836
 837 static void process_blocking_lock_cancel_message(struct messaging_context *ctx,
 838                                                  void *private_data,
 839                                                  uint32_t msg_type,
 840                                                  struct server_id server_id,
 841                                                  DATA_BLOB *data)
 842 {
 843         NTSTATUS err;
 844         const char *msg = (const char *)data->data;
 845         blocking_lock_record *blr;
 846
 847         if (data->data == NULL) {
 848                 smb_panic("process_blocking_lock_cancel_message: null msg");
 849         }
 850
 851         if (data->length != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 852                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 853                           "Got invalid msg len %d\n", (int)data->length));
 854                 smb_panic("process_blocking_lock_cancel_message: bad msg");
 855         }
 856
 857         memcpy(&blr, msg, sizeof(blr));
 858         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 859
 860         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 861                 nt_errstr(err) ));
 862
 863         blocking_lock_reply_error(blr, err);
 864         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 865         free_blocking_lock_record(blr);
 866 }
 867
 868 /****************************************************************************
 869  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 870 *****************************************************************************/
 871
 872 bool blocking_lock_cancel(files_struct *fsp,
 873                         uint32 lock_pid,
 874                         SMB_BIG_UINT offset,
 875                         SMB_BIG_UINT count,
 876                         enum brl_flavour lock_flav,
 877                         unsigned char locktype,
 878                         NTSTATUS err)
 879 {
 880         static bool initialized;
 881         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 882         blocking_lock_record *blr;
 883
 884         if (!initialized) {
 885                 /* Register our message. */
 886                 messaging_register(smbd_messaging_context(), NULL,
 887                                    MSG_SMB_BLOCKING_LOCK_CANCEL,
 888                                    process_blocking_lock_cancel_message);
 889
 890                 initialized = True;
 891         }
 892
 893         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 894                 if (fsp == blr->fsp &&
 895                                 lock_pid == blr->lock_pid &&
 896                                 offset == blr->offset &&
 897                                 count == blr->count &&
 898                                 lock_flav == blr->lock_flav) {
 899                         break;
 900                 }
 901         }
 902
 903         if (!blr) {
 904                 return False;
 905         }
 906
 907         /* Check the flags are right. */
 908         if (blr->com_type == SMBlockingX &&
 909                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 910                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 911                 return False;
 912         }
 913
 914         /* Move to cancelled queue. */
 915         DLIST_REMOVE(blocking_lock_queue, blr);
 916         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 917
 918         /* Create the message. */
 919         memcpy(msg, &blr, sizeof(blr));
 920         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 921
 922         messaging_send_buf(smbd_messaging_context(), procid_self(),
 923                            MSG_SMB_BLOCKING_LOCK_CANCEL,
 924                            (uint8 *)&msg, sizeof(msg));
 925
 926         return True;
 927 }