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         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(int msg_type, struct server_id src,
  78                                 void *buf, size_t len,
  79                                 void *private_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                 char *inbuf, int length,
 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         blocking_lock_record *blr;
 166         NTSTATUS status;
 167
 168         if(in_chained_smb() ) {
 169                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
 170                 return False;
 171         }
 172
 173         /*
 174          * Now queue an entry on the blocking lock queue. We setup
 175          * the expiration time here.
 176          */
 177
 178         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 179                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 180                 return False;
 181         }
 182
 183         blr->next = NULL;
 184         blr->prev = NULL;
 185
 186         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 187                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 188                 SAFE_FREE(blr);
 189                 return False;
 190         }
 191
 192         blr->com_type = CVAL(inbuf,smb_com);
 193         blr->fsp = fsp;
 194         if (lock_timeout == -1) {
 195                 blr->expire_time.tv_sec = 0;
 196                 blr->expire_time.tv_usec = 0; /* Never expire. */
 197         } else {
 198                 blr->expire_time = timeval_current_ofs(lock_timeout/1000,
 199                                         (lock_timeout % 1000) * 1000);
 200         }
 201         blr->lock_num = lock_num;
 202         blr->lock_pid = lock_pid;
 203         blr->blocking_pid = blocking_pid;
 204         blr->lock_flav = lock_flav;
 205         blr->lock_type = lock_type;
 206         blr->offset = offset;
 207         blr->count = count;
 208         memcpy(blr->inbuf, inbuf, length);
 209         blr->length = length;
 210
 211         /* Add a pending lock record for this. */
 212         status = brl_lock(smbd_messaging_context(), br_lck,
 213                         lock_pid,
 214                         procid_self(),
 215                         offset,
 216                         count,
 217                         lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
 218                         blr->lock_flav,
 219                         lock_timeout ? True : False, /* blocking_lock. */
 220                         NULL);
 221
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 224                 DLIST_REMOVE(blocking_lock_queue, blr);
 225                 free_blocking_lock_record(blr);
 226                 return False;
 227         }
 228
 229         DLIST_ADD_END(blocking_lock_queue, blr, blocking_lock_record *);
 230         recalc_brl_timeout();
 231
 232         /* Ensure we'll receive messages when this is unlocked. */
 233         if (!set_lock_msg) {
 234                 message_register(MSG_SMB_UNLOCK, received_unlock_msg,
 235                                  NULL);
 236                 set_lock_msg = True;
 237         }
 238
 239         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
 240                 "expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
 241                 length, (unsigned int)blr->expire_time.tv_sec,
 242                 (unsigned int)blr->expire_time.tv_usec, lock_timeout,
 243                 blr->fsp->fnum, blr->fsp->fsp_name ));
 244
 245         /* Push the MID of this packet on the signing queue. */
 246         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 247
 248         return True;
 249 }
 250
 251 /****************************************************************************
 252  Return a smd with a given size.
 253 *****************************************************************************/
 254
 255 static void send_blocking_reply(char *outbuf, int outsize, const char *inbuf)
 256 {
 257         if(outsize > 4) {
 258                 smb_setlen(inbuf, outbuf,outsize - 4);
 259         }
 260
 261         if (!send_smb(smbd_server_fd(),outbuf)) {
 262                 exit_server_cleanly("send_blocking_reply: send_smb failed.");
 263         }
 264 }
 265
 266 /****************************************************************************
 267  Return a lockingX success SMB.
 268 *****************************************************************************/
 269
 270 static void reply_lockingX_success(blocking_lock_record *blr)
 271 {
 272         char *outbuf = get_OutBuffer();
 273         int bufsize = BUFFER_SIZE;
 274         char *inbuf = blr->inbuf;
 275         int outsize = 0;
 276
 277         construct_reply_common(inbuf, outbuf);
 278         set_message(inbuf,outbuf,2,0,True);
 279
 280         /*
 281          * As this message is a lockingX call we must handle
 282          * any following chained message correctly.
 283          * This is normally handled in construct_reply(),
 284          * but as that calls switch_message, we can't use
 285          * that here and must set up the chain info manually.
 286          */
 287
 288         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 289
 290         outsize += chain_size;
 291
 292         send_blocking_reply(outbuf,outsize,inbuf);
 293 }
 294
 295 /****************************************************************************
 296  Return a generic lock fail error blocking call.
 297 *****************************************************************************/
 298
 299 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 300 {
 301         char *outbuf = get_OutBuffer();
 302         char *inbuf = blr->inbuf;
 303         construct_reply_common(inbuf, outbuf);
 304
 305         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 306            FILE_LOCK_CONFLICT! (tridge) */
 307         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 308                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 309         }
 310
 311         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 312                 /* Store the last lock error. */
 313                 files_struct *fsp = blr->fsp;
 314
 315                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 316                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 317                 fsp->last_lock_failure.context.pid = procid_self();
 318                 fsp->last_lock_failure.start = blr->offset;
 319                 fsp->last_lock_failure.size = blr->count;
 320                 fsp->last_lock_failure.fnum = fsp->fnum;
 321                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 322                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 323         }
 324
 325         ERROR_NT(status);
 326         if (!send_smb(smbd_server_fd(),outbuf)) {
 327                 exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
 328         }
 329 }
 330
 331 /****************************************************************************
 332  Return a lock fail error for a lockingX call. Undo all the locks we have
 333  obtained first.
 334 *****************************************************************************/
 335
 336 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 337 {
 338         char *inbuf = blr->inbuf;
 339         files_struct *fsp = blr->fsp;
 340         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 341         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 342         uint32 lock_pid;
 343         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 344         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 345         char *data;
 346         int i;
 347
 348         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 349
 350         /*
 351          * Data now points at the beginning of the list
 352          * of smb_lkrng structs.
 353          */
 354
 355         /*
 356          * Ensure we don't do a remove on the lock that just failed,
 357          * as under POSIX rules, if we have a lock already there, we
 358          * will delete it (and we shouldn't) .....
 359          */
 360
 361         for(i = blr->lock_num - 1; i >= 0; i--) {
 362                 BOOL err;
 363
 364                 lock_pid = get_lock_pid( data, i, large_file_format);
 365                 count = get_lock_count( data, i, large_file_format);
 366                 offset = get_lock_offset( data, i, large_file_format, &err);
 367
 368                 /*
 369                  * We know err cannot be set as if it was the lock
 370                  * request would never have been queued. JRA.
 371                  */
 372
 373                 do_unlock(smbd_messaging_context(),
 374                         fsp,
 375                         lock_pid,
 376                         count,
 377                         offset,
 378                         WINDOWS_LOCK);
 379         }
 380
 381         generic_blocking_lock_error(blr, status);
 382 }
 383
 384 /****************************************************************************
 385  Return a lock fail error.
 386 *****************************************************************************/
 387
 388 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 389 {
 390         switch(blr->com_type) {
 391         case SMBlockingX:
 392                 reply_lockingX_error(blr, status);
 393                 break;
 394         case SMBtrans2:
 395         case SMBtranss2:
 396                 {
 397                         char *outbuf = get_OutBuffer();
 398                         char *inbuf = blr->inbuf;
 399                         construct_reply_common(inbuf, outbuf);
 400                         /* construct_reply_common has done us the favor to pre-fill the
 401                          * command field with SMBtranss2 which is wrong :-)
 402                          */
 403                         SCVAL(outbuf,smb_com,SMBtrans2);
 404                         ERROR_NT(status);
 405                         if (!send_smb(smbd_server_fd(),outbuf)) {
 406                                 exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
 407                         }
 408                         break;
 409                 }
 410         default:
 411                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 412                 exit_server("PANIC - unknown type on blocking lock queue");
 413         }
 414 }
 415
 416 /****************************************************************************
 417  Attempt to finish off getting all pending blocking locks for a lockingX call.
 418  Returns True if we want to be removed from the list.
 419 *****************************************************************************/
 420
 421 static BOOL process_lockingX(blocking_lock_record *blr)
 422 {
 423         char *inbuf = blr->inbuf;
 424         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 425         files_struct *fsp = blr->fsp;
 426         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 427         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 428         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 429         uint32 lock_pid;
 430         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 431         char *data;
 432         NTSTATUS status = NT_STATUS_OK;
 433
 434         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 435
 436         /*
 437          * Data now points at the beginning of the list
 438          * of smb_lkrng structs.
 439          */
 440
 441         for(; blr->lock_num < num_locks; blr->lock_num++) {
 442                 struct byte_range_lock *br_lck = NULL;
 443                 BOOL err;
 444
 445                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 446                 count = get_lock_count( data, blr->lock_num, large_file_format);
 447                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 448
 449                 /*
 450                  * We know err cannot be set as if it was the lock
 451                  * request would never have been queued. JRA.
 452                  */
 453                 errno = 0;
 454                 br_lck = do_lock(smbd_messaging_context(),
 455                                 fsp,
 456                                 lock_pid,
 457                                 count,
 458                                 offset,
 459                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 460                                         READ_LOCK : WRITE_LOCK),
 461                                 WINDOWS_LOCK,
 462                                 True,
 463                                 &status,
 464                                 &blr->blocking_pid);
 465
 466                 TALLOC_FREE(br_lck);
 467
 468                 if (NT_STATUS_IS_ERR(status)) {
 469                         break;
 470                 }
 471         }
 472
 473         if(blr->lock_num == num_locks) {
 474                 /*
 475                  * Success - we got all the locks.
 476                  */
 477
 478                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 479                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 480
 481                 reply_lockingX_success(blr);
 482                 return True;
 483         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 484                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 485                         /*
 486                          * We have other than a "can't get lock"
 487                          * error. Free any locks we had and return an error.
 488                          * Return True so we get dequeued.
 489                          */
 490
 491                 blocking_lock_reply_error(blr, status);
 492                 return True;
 493         }
 494
 495         /*
 496          * Still can't get all the locks - keep waiting.
 497          */
 498
 499         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 500 Waiting....\n",
 501                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 502
 503         return False;
 504 }
 505
 506 /****************************************************************************
 507  Attempt to get the posix lock request from a SMBtrans2 call.
 508  Returns True if we want to be removed from the list.
 509 *****************************************************************************/
 510
 511 static BOOL process_trans2(blocking_lock_record *blr)
 512 {
 513         char *inbuf = blr->inbuf;
 514         char *outbuf;
 515         char params[2];
 516         NTSTATUS status;
 517         struct byte_range_lock *br_lck = do_lock(smbd_messaging_context(),
 518                                                 blr->fsp,
 519                                                 blr->lock_pid,
 520                                                 blr->count,
 521                                                 blr->offset,
 522                                                 blr->lock_type,
 523                                                 blr->lock_flav,
 524                                                 True,
 525                                                 &status,
 526                                                 &blr->blocking_pid);
 527         TALLOC_FREE(br_lck);
 528
 529         if (!NT_STATUS_IS_OK(status)) {
 530                 if (ERROR_WAS_LOCK_DENIED(status)) {
 531                         /* Still can't get the lock, just keep waiting. */
 532                         return False;
 533                 }
 534                 /*
 535                  * We have other than a "can't get lock"
 536                  * error. Send an error and return True so we get dequeued.
 537                  */
 538                 blocking_lock_reply_error(blr, status);
 539                 return True;
 540         }
 541
 542         /* We finally got the lock, return success. */
 543         outbuf = get_OutBuffer();
 544         construct_reply_common(inbuf, outbuf);
 545         SCVAL(outbuf,smb_com,SMBtrans2);
 546         SSVAL(params,0,0);
 547         /* Fake up max_data_bytes here - we know it fits. */
 548         send_trans2_replies(inbuf, outbuf, max_send, params, 2, NULL, 0, 0xffff);
 549         return True;
 550 }
 551
 552
 553 /****************************************************************************
 554  Process a blocking lock SMB.
 555  Returns True if we want to be removed from the list.
 556 *****************************************************************************/
 557
 558 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 559 {
 560         switch(blr->com_type) {
 561                 case SMBlockingX:
 562                         return process_lockingX(blr);
 563                 case SMBtrans2:
 564                 case SMBtranss2:
 565                         return process_trans2(blr);
 566                 default:
 567                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 568                         exit_server("PANIC - unknown type on blocking lock queue");
 569         }
 570         return False; /* Keep compiler happy. */
 571 }
 572
 573 /****************************************************************************
 574  Cancel entries by fnum from the blocking lock pending queue.
 575 *****************************************************************************/
 576
 577 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 578 {
 579         blocking_lock_record *blr, *next = NULL;
 580
 581         for(blr = blocking_lock_queue; blr; blr = next) {
 582                 next = blr->next;
 583                 if(blr->fsp->fnum == fsp->fnum) {
 584                         unsigned char locktype = 0;
 585
 586                         if (blr->com_type == SMBlockingX) {
 587                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 588                         }
 589
 590                         if (br_lck) {
 591                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 592 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 593
 594                                 brl_lock_cancel(br_lck,
 595                                         blr->lock_pid,
 596                                         procid_self(),
 597                                         blr->offset,
 598                                         blr->count,
 599                                         blr->lock_flav);
 600
 601                                 blocking_lock_cancel(fsp,
 602                                         blr->lock_pid,
 603                                         blr->offset,
 604                                         blr->count,
 605                                         blr->lock_flav,
 606                                         locktype,
 607                                         NT_STATUS_RANGE_NOT_LOCKED);
 608                         }
 609                 }
 610         }
 611 }
 612
 613 /****************************************************************************
 614  Delete entries by mid from the blocking lock pending queue. Always send reply.
 615 *****************************************************************************/
 616
 617 void remove_pending_lock_requests_by_mid(int mid)
 618 {
 619         blocking_lock_record *blr, *next = NULL;
 620
 621         for(blr = blocking_lock_queue; blr; blr = next) {
 622                 next = blr->next;
 623                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 624                         files_struct *fsp = blr->fsp;
 625                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 626
 627                         if (br_lck) {
 628                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 629 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 630
 631                                 brl_lock_cancel(br_lck,
 632                                         blr->lock_pid,
 633                                         procid_self(),
 634                                         blr->offset,
 635                                         blr->count,
 636                                         blr->lock_flav);
 637                                 TALLOC_FREE(br_lck);
 638                         }
 639
 640                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 641                         DLIST_REMOVE(blocking_lock_queue, blr);
 642                         free_blocking_lock_record(blr);
 643                 }
 644         }
 645 }
 646
 647 /****************************************************************************
 648  Is this mid a blocking lock request on the queue ?
 649 *****************************************************************************/
 650
 651 BOOL blocking_lock_was_deferred(int mid)
 652 {
 653         blocking_lock_record *blr, *next = NULL;
 654
 655         for(blr = blocking_lock_queue; blr; blr = next) {
 656                 next = blr->next;
 657                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 658                         return True;
 659                 }
 660         }
 661         return False;
 662 }
 663
 664 /****************************************************************************
 665   Set a flag as an unlock request affects one of our pending locks.
 666 *****************************************************************************/
 667
 668 static void received_unlock_msg(int msg_type, struct server_id src,
 669                                 void *buf, size_t len,
 670                                 void *private_data)
 671 {
 672         DEBUG(10,("received_unlock_msg\n"));
 673         process_blocking_lock_queue();
 674 }
 675
 676 /****************************************************************************
 677  Process the blocking lock queue. Note that this is only called as root.
 678 *****************************************************************************/
 679
 680 static void process_blocking_lock_queue(void)
 681 {
 682         struct timeval tv_curr = timeval_current();
 683         blocking_lock_record *blr, *next = NULL;
 684         BOOL recalc_timeout = False;
 685
 686         /*
 687          * Go through the queue and see if we can get any of the locks.
 688          */
 689
 690         for (blr = blocking_lock_queue; blr; blr = next) {
 691                 connection_struct *conn = NULL;
 692                 uint16 vuid;
 693                 files_struct *fsp = NULL;
 694
 695                 next = blr->next;
 696
 697                 /*
 698                  * Ensure we don't have any old chain_fsp values
 699                  * sitting around....
 700                  */
 701                 chain_size = 0;
 702                 file_chain_reset();
 703                 fsp = blr->fsp;
 704
 705                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 706                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 707                                 SVAL(blr->inbuf,smb_uid);
 708
 709                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 710                         fsp->fnum, fsp->fsp_name ));
 711
 712                 if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
 713                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 714
 715                         /*
 716                          * Lock expired - throw away all previously
 717                          * obtained locks and return lock error.
 718                          */
 719
 720                         if (br_lck) {
 721                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 722                                         fsp->fnum, fsp->fsp_name ));
 723
 724                                 brl_lock_cancel(br_lck,
 725                                         blr->lock_pid,
 726                                         procid_self(),
 727                                         blr->offset,
 728                                         blr->count,
 729                                         blr->lock_flav);
 730                                 TALLOC_FREE(br_lck);
 731                         }
 732
 733                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 734                         DLIST_REMOVE(blocking_lock_queue, blr);
 735                         free_blocking_lock_record(blr);
 736                         recalc_timeout = True;
 737                         continue;
 738                 }
 739
 740                 if(!change_to_user(conn,vuid)) {
 741                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 742
 743                         /*
 744                          * Remove the entry and return an error to the client.
 745                          */
 746
 747                         if (br_lck) {
 748                                 brl_lock_cancel(br_lck,
 749                                         blr->lock_pid,
 750                                         procid_self(),
 751                                         blr->offset,
 752                                         blr->count,
 753                                         blr->lock_flav);
 754                                 TALLOC_FREE(br_lck);
 755                         }
 756
 757                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 758                                 vuid ));
 759                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 760                         DLIST_REMOVE(blocking_lock_queue, blr);
 761                         free_blocking_lock_record(blr);
 762                         recalc_timeout = True;
 763                         continue;
 764                 }
 765
 766                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 767                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 768
 769                         /*
 770                          * Remove the entry and return an error to the client.
 771                          */
 772
 773                         if (br_lck) {
 774                                 brl_lock_cancel(br_lck,
 775                                         blr->lock_pid,
 776                                         procid_self(),
 777                                         blr->offset,
 778                                         blr->count,
 779                                         blr->lock_flav);
 780                                 TALLOC_FREE(br_lck);
 781                         }
 782
 783                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 784                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 785                         DLIST_REMOVE(blocking_lock_queue, blr);
 786                         free_blocking_lock_record(blr);
 787                         recalc_timeout = True;
 788                         change_to_root_user();
 789                         continue;
 790                 }
 791
 792                 /*
 793                  * Go through the remaining locks and try and obtain them.
 794                  * The call returns True if all locks were obtained successfully
 795                  * and False if we still need to wait.
 796                  */
 797
 798                 if(blocking_lock_record_process(blr)) {
 799                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 800
 801                         if (br_lck) {
 802                                 brl_lock_cancel(br_lck,
 803                                         blr->lock_pid,
 804                                         procid_self(),
 805                                         blr->offset,
 806                                         blr->count,
 807                                         blr->lock_flav);
 808                                 TALLOC_FREE(br_lck);
 809                         }
 810
 811                         DLIST_REMOVE(blocking_lock_queue, blr);
 812                         free_blocking_lock_record(blr);
 813                         recalc_timeout = True;
 814                 }
 815                 change_to_root_user();
 816         }
 817
 818         if (recalc_timeout) {
 819                 recalc_brl_timeout();
 820         }
 821 }
 822
 823 /****************************************************************************
 824  Handle a cancel message. Lock already moved onto the cancel queue.
 825 *****************************************************************************/
 826
 827 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 828
 829 static void process_blocking_lock_cancel_message(int msg_type,
 830                                                  struct server_id src,
 831                                                  void *buf, size_t len,
 832                                                  void *private_data)
 833 {
 834         NTSTATUS err;
 835         const char *msg = (const char *)buf;
 836         blocking_lock_record *blr;
 837
 838         if (buf == NULL) {
 839                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 840         }
 841
 842         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 843                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 844                         "Got invalid msg len %d\n", (int)len));
 845                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 846         }
 847
 848         memcpy(&blr, msg, sizeof(blr));
 849         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 850
 851         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 852                 nt_errstr(err) ));
 853
 854         blocking_lock_reply_error(blr, err);
 855         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 856         free_blocking_lock_record(blr);
 857 }
 858
 859 /****************************************************************************
 860  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 861 *****************************************************************************/
 862
 863 BOOL blocking_lock_cancel(files_struct *fsp,
 864                         uint32 lock_pid,
 865                         SMB_BIG_UINT offset,
 866                         SMB_BIG_UINT count,
 867                         enum brl_flavour lock_flav,
 868                         unsigned char locktype,
 869                         NTSTATUS err)
 870 {
 871         static BOOL initialized;
 872         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 873         blocking_lock_record *blr;
 874
 875         if (!initialized) {
 876                 /* Register our message. */
 877                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 878                                  process_blocking_lock_cancel_message,
 879                                  NULL);
 880
 881                 initialized = True;
 882         }
 883
 884         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 885                 if (fsp == blr->fsp &&
 886                                 lock_pid == blr->lock_pid &&
 887                                 offset == blr->offset &&
 888                                 count == blr->count &&
 889                                 lock_flav == blr->lock_flav) {
 890                         break;
 891                 }
 892         }
 893
 894         if (!blr) {
 895                 return False;
 896         }
 897
 898         /* Check the flags are right. */
 899         if (blr->com_type == SMBlockingX &&
 900                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 901                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 902                 return False;
 903         }
 904
 905         /* Move to cancelled queue. */
 906         DLIST_REMOVE(blocking_lock_queue, blr);
 907         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 908
 909         /* Create the message. */
 910         memcpy(msg, &blr, sizeof(blr));
 911         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 912
 913         messaging_send_buf(smbd_messaging_context(), procid_self(),
 914                            MSG_SMB_BLOCKING_LOCK_CANCEL,
 915                            (uint8 *)&msg, sizeof(msg));
 916
 917         return True;
 918 }