source3/smbd/oplock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    oplock processing
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1998 - 2001
   6    Copyright (C) Volker Lendecke 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #define DBGC_CLASS DBGC_LOCKING
  23 #include "includes.h"
  24 #include "smbd/globals.h"
  25
  26 /****************************************************************************
  27  Get the number of current exclusive oplocks.
  28 ****************************************************************************/
  29
  30 int32 get_number_of_exclusive_open_oplocks(void)
  31 {
  32   return exclusive_oplocks_open;
  33 }
  34
  35 /*
  36  * helper function used by the kernel oplock backends to post the break message
  37  */
  38 void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
  39 {
  40         uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
  41
  42         /* Put the kernel break info into the message. */
  43         push_file_id_24((char *)msg, &fsp->file_id);
  44         SIVAL(msg,24,fsp->fh->gen_id);
  45
  46         /* Don't need to be root here as we're only ever
  47            sending to ourselves. */
  48
  49         messaging_send_buf(msg_ctx, procid_self(),
  50                            MSG_SMB_KERNEL_BREAK,
  51                            msg, MSG_SMB_KERNEL_BREAK_SIZE);
  52 }
  53
  54 /****************************************************************************
  55  Attempt to set an oplock on a file. Always succeeds if kernel oplocks are
  56  disabled (just sets flags). Returns True if oplock set.
  57 ****************************************************************************/
  58
  59 bool set_file_oplock(files_struct *fsp, int oplock_type)
  60 {
  61         if ((fsp->oplock_type == LEVEL_II_OPLOCK)
  62             && koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  63                 DEBUG(10, ("Refusing level2 oplock, kernel oplocks don't "
  64                            "support them\n"));
  65                 return false;
  66         }
  67         if ((fsp->oplock_type != NO_OPLOCK) &&
  68             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  69             koplocks &&
  70             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type)) {
  71                 return False;
  72         }
  73
  74         fsp->oplock_type = oplock_type;
  75         fsp->sent_oplock_break = NO_BREAK_SENT;
  76         if (oplock_type == LEVEL_II_OPLOCK) {
  77                 level_II_oplocks_open++;
  78         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  79                 exclusive_oplocks_open++;
  80         }
  81
  82         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  83                     "tv_sec = %x, tv_usec = %x\n",
  84                  fsp->fsp_name, file_id_string_tos(&fsp->file_id),
  85                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  86                  (int)fsp->open_time.tv_usec ));
  87
  88         return True;
  89 }
  90
  91 /****************************************************************************
  92  Attempt to release an oplock on a file. Decrements oplock count.
  93 ****************************************************************************/
  94
  95 void release_file_oplock(files_struct *fsp)
  96 {
  97         if ((fsp->oplock_type != NO_OPLOCK) &&
  98             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  99             koplocks) {
 100                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 101         }
 102
 103         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 104                 level_II_oplocks_open--;
 105         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 106                 exclusive_oplocks_open--;
 107         }
 108
 109         SMB_ASSERT(exclusive_oplocks_open>=0);
 110         SMB_ASSERT(level_II_oplocks_open>=0);
 111
 112         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 113                 /* This doesn't matter for close. */
 114                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 115         } else {
 116                 fsp->oplock_type = NO_OPLOCK;
 117         }
 118         fsp->sent_oplock_break = NO_BREAK_SENT;
 119
 120         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 121         delete_write_cache(fsp);
 122
 123         TALLOC_FREE(fsp->oplock_timeout);
 124 }
 125
 126 /****************************************************************************
 127  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 128 ****************************************************************************/
 129
 130 static void downgrade_file_oplock(files_struct *fsp)
 131 {
 132         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 133                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 134                 return;
 135         }
 136
 137         if (koplocks) {
 138                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 139         }
 140         fsp->oplock_type = LEVEL_II_OPLOCK;
 141         exclusive_oplocks_open--;
 142         level_II_oplocks_open++;
 143         fsp->sent_oplock_break = NO_BREAK_SENT;
 144 }
 145
 146 /****************************************************************************
 147  Remove a file oplock. Copes with level II and exclusive.
 148  Locks then unlocks the share mode lock. Client can decide to go directly
 149  to none even if a "break-to-level II" was sent.
 150 ****************************************************************************/
 151
 152 bool remove_oplock(files_struct *fsp)
 153 {
 154         bool ret;
 155         struct share_mode_lock *lck;
 156
 157         /* Remove the oplock flag from the sharemode. */
 158         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 159                                   NULL);
 160         if (lck == NULL) {
 161                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 162                          "file %s\n", fsp->fsp_name ));
 163                 return False;
 164         }
 165         ret = remove_share_oplock(lck, fsp);
 166         if (!ret) {
 167                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 168                          "file %s fnum %d, %s\n",
 169                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 170         }
 171         release_file_oplock(fsp);
 172         TALLOC_FREE(lck);
 173         return ret;
 174 }
 175
 176 /*
 177  * Deal with a reply when a break-to-level II was sent.
 178  */
 179 bool downgrade_oplock(files_struct *fsp)
 180 {
 181         bool ret;
 182         struct share_mode_lock *lck;
 183
 184         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 185                                   NULL);
 186         if (lck == NULL) {
 187                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 188                          "file %s\n", fsp->fsp_name ));
 189                 return False;
 190         }
 191         ret = downgrade_share_oplock(lck, fsp);
 192         if (!ret) {
 193                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 194                          "for file %s fnum %d, file_id %s\n",
 195                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 196         }
 197
 198         downgrade_file_oplock(fsp);
 199         TALLOC_FREE(lck);
 200         return ret;
 201 }
 202
 203 /*
 204  * Some kernel oplock implementations handle the notification themselves.
 205  */
 206 bool should_notify_deferred_opens()
 207 {
 208         return !(koplocks &&
 209                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 210 }
 211
 212 /****************************************************************************
 213  Set up an oplock break message.
 214 ****************************************************************************/
 215
 216 static char *new_break_smb_message(TALLOC_CTX *mem_ctx,
 217                                    files_struct *fsp, uint8 cmd)
 218 {
 219         char *result = TALLOC_ARRAY(mem_ctx, char, smb_size + 8*2 + 0);
 220
 221         if (result == NULL) {
 222                 DEBUG(0, ("talloc failed\n"));
 223                 return NULL;
 224         }
 225
 226         memset(result,'\0',smb_size);
 227         srv_set_message(result,8,0,true);
 228         SCVAL(result,smb_com,SMBlockingX);
 229         SSVAL(result,smb_tid,fsp->conn->cnum);
 230         SSVAL(result,smb_pid,0xFFFF);
 231         SSVAL(result,smb_uid,0);
 232         SSVAL(result,smb_mid,0xFFFF);
 233         SCVAL(result,smb_vwv0,0xFF);
 234         SSVAL(result,smb_vwv2,fsp->fnum);
 235         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 236         SCVAL(result,smb_vwv3+1,cmd);
 237         return result;
 238 }
 239
 240 /****************************************************************************
 241  Function to do the waiting before sending a local break.
 242 ****************************************************************************/
 243
 244 static void wait_before_sending_break(void)
 245 {
 246         long wait_time = (long)lp_oplock_break_wait_time();
 247
 248         if (wait_time) {
 249                 smb_msleep(wait_time);
 250         }
 251 }
 252
 253 /****************************************************************************
 254  Ensure that we have a valid oplock.
 255 ****************************************************************************/
 256
 257 static files_struct *initial_break_processing(struct file_id id, unsigned long file_id)
 258 {
 259         files_struct *fsp = NULL;
 260
 261         if( DEBUGLVL( 3 ) ) {
 262                 dbgtext( "initial_break_processing: called for %s/%u\n",
 263                          file_id_string_tos(&id), (int)file_id);
 264                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 265                         exclusive_oplocks_open, level_II_oplocks_open );
 266         }
 267
 268         /*
 269          * We need to search the file open table for the
 270          * entry containing this dev and inode, and ensure
 271          * we have an oplock on it.
 272          */
 273
 274         fsp = file_find_dif(id, file_id);
 275
 276         if(fsp == NULL) {
 277                 /* The file could have been closed in the meantime - return success. */
 278                 if( DEBUGLVL( 3 ) ) {
 279                         dbgtext( "initial_break_processing: cannot find open file with " );
 280                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 281                         dbgtext( "allowing break to succeed.\n" );
 282                 }
 283                 return NULL;
 284         }
 285
 286         /* Ensure we have an oplock on the file */
 287
 288         /*
 289          * There is a potential race condition in that an oplock could
 290          * have been broken due to another udp request, and yet there are
 291          * still oplock break messages being sent in the udp message
 292          * queue for this file. So return true if we don't have an oplock,
 293          * as we may have just freed it.
 294          */
 295
 296         if(fsp->oplock_type == NO_OPLOCK) {
 297                 if( DEBUGLVL( 3 ) ) {
 298                         dbgtext( "initial_break_processing: file %s ", fsp->fsp_name );
 299                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 300                                  file_id_string_tos(&id), fsp->fh->gen_id );
 301                         dbgtext( "Allowing break to succeed regardless.\n" );
 302                 }
 303                 return NULL;
 304         }
 305
 306         return fsp;
 307 }
 308
 309 static void oplock_timeout_handler(struct event_context *ctx,
 310                                    struct timed_event *te,
 311                                    struct timeval now,
 312                                    void *private_data)
 313 {
 314         files_struct *fsp = (files_struct *)private_data;
 315
 316         /* Remove the timed event handler. */
 317         TALLOC_FREE(fsp->oplock_timeout);
 318         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n", fsp->fsp_name));
 319         global_client_failed_oplock_break = True;
 320         remove_oplock(fsp);
 321         reply_to_oplock_break_requests(fsp);
 322 }
 323
 324 /*******************************************************************
 325  Add a timeout handler waiting for the client reply.
 326 *******************************************************************/
 327
 328 static void add_oplock_timeout_handler(files_struct *fsp)
 329 {
 330         /*
 331          * If kernel oplocks already notifies smbds when an oplock break times
 332          * out, just return.
 333          */
 334         if (koplocks &&
 335             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 336                 return;
 337         }
 338
 339         if (fsp->oplock_timeout != NULL) {
 340                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 341                           "around\n"));
 342         }
 343
 344         fsp->oplock_timeout =
 345                 event_add_timed(smbd_event_context(), NULL,
 346                                 timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 347                                 oplock_timeout_handler, fsp);
 348
 349         if (fsp->oplock_timeout == NULL) {
 350                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 351         }
 352 }
 353
 354 void break_level2_to_none_async(files_struct *fsp)
 355 {
 356         char *break_msg;
 357         bool sign_state;
 358
 359         if (fsp->oplock_type == NO_OPLOCK) {
 360                 /* We already got a "break to none" message and we've handled
 361                  * it.  just ignore. */
 362                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 363                           "broken to none, ignoring.\n"));
 364                 return;
 365         }
 366
 367         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 368                 /* Don't tell the client, just downgrade. */
 369                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 370                           "downgrading fake level 2 oplock.\n"));
 371                 remove_oplock(fsp);
 372                 return;
 373         }
 374
 375         /* Ensure we're really at level2 state. */
 376         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 377
 378         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 379                   "to none message for fid %d, file %s\n", fsp->fnum,
 380                   fsp->fsp_name));
 381
 382         /* Now send a break to none message to our client. */
 383         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 384         if (break_msg == NULL) {
 385                 exit_server("Could not talloc break_msg\n");
 386         }
 387
 388         /* Save the server smb signing state. */
 389         sign_state = srv_oplock_set_signing(False);
 390
 391         show_msg(break_msg);
 392         if (!srv_send_smb(smbd_server_fd(),
 393                         break_msg,
 394                         IS_CONN_ENCRYPTED(fsp->conn),
 395                         NULL)) {
 396                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 397         }
 398
 399         /* Restore the sign state to what it was. */
 400         srv_oplock_set_signing(sign_state);
 401
 402         TALLOC_FREE(break_msg);
 403
 404         /* Async level2 request, don't send a reply, just remove the oplock. */
 405         remove_oplock(fsp);
 406
 407 }
 408
 409 /*******************************************************************
 410  This handles the case of a write triggering a break to none
 411  message on a level2 oplock.
 412  When we get this message we may be in any of three states :
 413  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 414  the client for LEVEL2.
 415 *******************************************************************/
 416
 417 void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 418                                                       void *private_data,
 419                                                       uint32_t msg_type,
 420                                                       struct server_id src,
 421                                                       DATA_BLOB *data)
 422 {
 423         struct share_mode_entry msg;
 424         files_struct *fsp;
 425
 426         if (data->data == NULL) {
 427                 DEBUG(0, ("Got NULL buffer\n"));
 428                 return;
 429         }
 430
 431         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 432                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 433                 return;
 434         }
 435
 436         /* De-linearize incoming message. */
 437         message_to_share_mode_entry(&msg, (char *)data->data);
 438
 439         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 440                    "%s/%lu\n", procid_str(debug_ctx(), &src),
 441                    file_id_string_tos(&msg.id), msg.share_file_id));
 442
 443         fsp = initial_break_processing(msg.id, msg.share_file_id);
 444
 445         if (fsp == NULL) {
 446                 /* We hit a race here. Break messages are sent, and before we
 447                  * get to process this message, we have closed the file.
 448                  * No need to reply as this is an async message. */
 449                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 450                 return;
 451         }
 452
 453         break_level2_to_none_async(fsp);
 454 }
 455
 456 /*******************************************************************
 457  This handles the generic oplock break message from another smbd.
 458 *******************************************************************/
 459
 460 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 461                                          void *private_data,
 462                                          uint32_t msg_type,
 463                                          struct server_id src,
 464                                          DATA_BLOB *data)
 465 {
 466         struct share_mode_entry msg;
 467         files_struct *fsp;
 468         char *break_msg;
 469         bool break_to_level2 = False;
 470         bool sign_state;
 471
 472         if (data->data == NULL) {
 473                 DEBUG(0, ("Got NULL buffer\n"));
 474                 return;
 475         }
 476
 477         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 478                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 479                 return;
 480         }
 481
 482         /* De-linearize incoming message. */
 483         message_to_share_mode_entry(&msg, (char *)data->data);
 484
 485         DEBUG(10, ("Got oplock break message from pid %s: %s/%lu\n",
 486                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 487                    msg.share_file_id));
 488
 489         fsp = initial_break_processing(msg.id, msg.share_file_id);
 490
 491         if (fsp == NULL) {
 492                 /* a We hit race here. Break messages are sent, and before we
 493                  * get to process this message, we have closed the file. Reply
 494                  * with 'ok, oplock broken' */
 495                 DEBUG(3, ("Did not find fsp\n"));
 496
 497                 /* We just send the same message back. */
 498                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 499                                    (uint8 *)data->data,
 500                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 501                 return;
 502         }
 503
 504         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 505                 /* Remember we have to inform the requesting PID when the
 506                  * client replies */
 507                 msg.pid = src;
 508                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 509                              &fsp->pending_break_messages,
 510                              &fsp->num_pending_break_messages);
 511                 return;
 512         }
 513
 514         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 515             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 516                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 517                           file_id_string_tos(&fsp->file_id),
 518                           fsp->fsp_name));
 519                 /* We just send the same message back. */
 520                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 521                                    (uint8 *)data->data,
 522                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 523                 return;
 524         }
 525
 526         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 527             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 528             !(koplocks && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 529             lp_level2_oplocks(SNUM(fsp->conn))) {
 530                 break_to_level2 = True;
 531         }
 532
 533         break_msg = new_break_smb_message(NULL, fsp, break_to_level2 ?
 534                                           OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 535         if (break_msg == NULL) {
 536                 exit_server("Could not talloc break_msg\n");
 537         }
 538
 539         /* Need to wait before sending a break message if we sent ourselves this message. */
 540         if (procid_is_me(&src)) {
 541                 wait_before_sending_break();
 542         }
 543
 544         /* Save the server smb signing state. */
 545         sign_state = srv_oplock_set_signing(False);
 546
 547         show_msg(break_msg);
 548         if (!srv_send_smb(smbd_server_fd(),
 549                         break_msg,
 550                         IS_CONN_ENCRYPTED(fsp->conn),
 551                         NULL)) {
 552                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 553         }
 554
 555         /* Restore the sign state to what it was. */
 556         srv_oplock_set_signing(sign_state);
 557
 558         TALLOC_FREE(break_msg);
 559
 560         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 561
 562         msg.pid = src;
 563         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 564                      &fsp->pending_break_messages,
 565                      &fsp->num_pending_break_messages);
 566
 567         add_oplock_timeout_handler(fsp);
 568 }
 569
 570 /*******************************************************************
 571  This handles the kernel oplock break message.
 572 *******************************************************************/
 573
 574 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 575                                         void *private_data,
 576                                         uint32_t msg_type,
 577                                         struct server_id src,
 578                                         DATA_BLOB *data)
 579 {
 580         struct file_id id;
 581         unsigned long file_id;
 582         files_struct *fsp;
 583         char *break_msg;
 584         bool sign_state;
 585
 586         if (data->data == NULL) {
 587                 DEBUG(0, ("Got NULL buffer\n"));
 588                 return;
 589         }
 590
 591         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 592                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 593                 return;
 594         }
 595
 596         /* Pull the data from the message. */
 597         pull_file_id_24((char *)data->data, &id);
 598         file_id = (unsigned long)IVAL(data->data, 24);
 599
 600         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 601                    procid_str(debug_ctx(), &src), file_id_string_tos(&id),
 602                    (unsigned int)file_id));
 603
 604         fsp = initial_break_processing(id, file_id);
 605
 606         if (fsp == NULL) {
 607                 DEBUG(3, ("Got a kernel oplock break message for a file "
 608                           "I don't know about\n"));
 609                 return;
 610         }
 611
 612         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 613                 /* This is ok, kernel oplocks come in completely async */
 614                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 615                           "break reply\n"));
 616                 return;
 617         }
 618
 619         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 620         if (break_msg == NULL) {
 621                 exit_server("Could not talloc break_msg\n");
 622         }
 623
 624         /* Save the server smb signing state. */
 625         sign_state = srv_oplock_set_signing(False);
 626
 627         show_msg(break_msg);
 628         if (!srv_send_smb(smbd_server_fd(),
 629                         break_msg,
 630                         IS_CONN_ENCRYPTED(fsp->conn),
 631                         NULL)) {
 632                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 633         }
 634
 635         /* Restore the sign state to what it was. */
 636         srv_oplock_set_signing(sign_state);
 637
 638         TALLOC_FREE(break_msg);
 639
 640         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 641
 642         add_oplock_timeout_handler(fsp);
 643 }
 644
 645 void reply_to_oplock_break_requests(files_struct *fsp)
 646 {
 647         int i;
 648
 649         /*
 650          * If kernel oplocks already notifies smbds when oplocks are
 651          * broken/removed, just return.
 652          */
 653         if (koplocks &&
 654             (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
 655                 return;
 656         }
 657
 658         for (i=0; i<fsp->num_pending_break_messages; i++) {
 659                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 660                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 661
 662                 share_mode_entry_to_message(msg, e);
 663
 664                 messaging_send_buf(smbd_messaging_context(), e->pid,
 665                                    MSG_SMB_BREAK_RESPONSE,
 666                                    (uint8 *)msg,
 667                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 668         }
 669
 670         SAFE_FREE(fsp->pending_break_messages);
 671         fsp->num_pending_break_messages = 0;
 672         if (fsp->oplock_timeout != NULL) {
 673                 /* Remove the timed event handler. */
 674                 TALLOC_FREE(fsp->oplock_timeout);
 675                 fsp->oplock_timeout = NULL;
 676         }
 677         return;
 678 }
 679
 680 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 681                                           void *private_data,
 682                                           uint32_t msg_type,
 683                                           struct server_id src,
 684                                           DATA_BLOB *data)
 685 {
 686         struct share_mode_entry msg;
 687
 688         if (data->data == NULL) {
 689                 DEBUG(0, ("Got NULL buffer\n"));
 690                 return;
 691         }
 692
 693         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 694                 DEBUG(0, ("Got invalid msg len %u\n",
 695                           (unsigned int)data->length));
 696                 return;
 697         }
 698
 699         /* De-linearize incoming message. */
 700         message_to_share_mode_entry(&msg, (char *)data->data);
 701
 702         DEBUG(10, ("Got oplock break response from pid %s: %s/%lu mid %u\n",
 703                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 704                    msg.share_file_id, (unsigned int)msg.op_mid));
 705
 706         /* Here's the hack from open.c, store the mid in the 'port' field */
 707         schedule_deferred_open_smb_message(msg.op_mid);
 708 }
 709
 710 static void process_open_retry_message(struct messaging_context *msg_ctx,
 711                                        void *private_data,
 712                                        uint32_t msg_type,
 713                                        struct server_id src,
 714                                        DATA_BLOB *data)
 715 {
 716         struct share_mode_entry msg;
 717
 718         if (data->data == NULL) {
 719                 DEBUG(0, ("Got NULL buffer\n"));
 720                 return;
 721         }
 722
 723         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 724                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 725                 return;
 726         }
 727
 728         /* De-linearize incoming message. */
 729         message_to_share_mode_entry(&msg, (char *)data->data);
 730
 731         DEBUG(10, ("Got open retry msg from pid %s: %s mid %u\n",
 732                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 733                    (unsigned int)msg.op_mid));
 734
 735         schedule_deferred_open_smb_message(msg.op_mid);
 736 }
 737
 738 /****************************************************************************
 739  This function is called on any file modification or lock request. If a file
 740  is level 2 oplocked then it must tell all other level 2 holders to break to
 741  none.
 742 ****************************************************************************/
 743
 744 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 745                                               enum level2_contention_type type)
 746 {
 747         int i;
 748         struct share_mode_lock *lck;
 749
 750         /*
 751          * If this file is level II oplocked then we need
 752          * to grab the shared memory lock and inform all
 753          * other files with a level II lock that they need
 754          * to flush their read caches. We keep the lock over
 755          * the shared memory area whilst doing this.
 756          */
 757
 758         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 759                 return;
 760
 761         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 762                                   NULL);
 763         if (lck == NULL) {
 764                 DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
 765                          "share mode entry for file %s.\n", fsp->fsp_name ));
 766                 return;
 767         }
 768
 769         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 770                   lck->num_share_modes ));
 771
 772         for(i = 0; i < lck->num_share_modes; i++) {
 773                 struct share_mode_entry *share_entry = &lck->share_modes[i];
 774                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 775
 776                 if (!is_valid_share_mode_entry(share_entry)) {
 777                         continue;
 778                 }
 779
 780                 /*
 781                  * As there could have been multiple writes waiting at the
 782                  * lock_share_entry gate we may not be the first to
 783                  * enter. Hence the state of the op_types in the share mode
 784                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 785                  * oplock. It will do no harm to re-send break messages to
 786                  * those smbd's that are still waiting their turn to remove
 787                  * their LEVEL_II state, and also no harm to ignore existing
 788                  * NO_OPLOCK states. JRA.
 789                  */
 790
 791                 DEBUG(10,("release_level_2_oplocks_on_change: "
 792                           "share_entry[%i]->op_type == %d\n",
 793                           i, share_entry->op_type ));
 794
 795                 if (share_entry->op_type == NO_OPLOCK) {
 796                         continue;
 797                 }
 798
 799                 /* Paranoia .... */
 800                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 801                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 802                                  "share mode entry %d is an exlusive "
 803                                  "oplock !\n", i ));
 804                         TALLOC_FREE(lck);
 805                         abort();
 806                 }
 807
 808                 share_mode_entry_to_message(msg, share_entry);
 809
 810                 /*
 811                  * Deal with a race condition when breaking level2
 812                  * oplocks. Don't send all the messages and release
 813                  * the lock, this allows someone else to come in and
 814                  * get a level2 lock before any of the messages are
 815                  * processed, and thus miss getting a break message.
 816                  * Ensure at least one entry (the one we're breaking)
 817                  * is processed immediately under the lock and becomes
 818                  * set as NO_OPLOCK to stop any waiter getting a level2.
 819                  * Bugid #5980.
 820                  */
 821
 822                 if (procid_is_me(&share_entry->pid)) {
 823                         wait_before_sending_break();
 824                         break_level2_to_none_async(fsp);
 825                 } else {
 826                         messaging_send_buf(smbd_messaging_context(),
 827                                         share_entry->pid,
 828                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 829                                         (uint8 *)msg,
 830                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 831                 }
 832         }
 833
 834         /* We let the message receivers handle removing the oplock state
 835            in the share mode lock db. */
 836
 837         TALLOC_FREE(lck);
 838 }
 839
 840 void contend_level2_oplocks_begin(files_struct *fsp,
 841                                   enum level2_contention_type type)
 842 {
 843         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 844                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 845                 return;
 846         }
 847
 848         contend_level2_oplocks_begin_default(fsp, type);
 849 }
 850
 851 void contend_level2_oplocks_end(files_struct *fsp,
 852                                 enum level2_contention_type type)
 853 {
 854         /* Only kernel oplocks implement this so far */
 855         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 856                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 857         }
 858 }
 859
 860 /****************************************************************************
 861  Linearize a share mode entry struct to an internal oplock break message.
 862 ****************************************************************************/
 863
 864 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 865 {
 866         SIVAL(msg,0,(uint32)e->pid.pid);
 867         SSVAL(msg,4,e->op_mid);
 868         SSVAL(msg,6,e->op_type);
 869         SIVAL(msg,8,e->access_mask);
 870         SIVAL(msg,12,e->share_access);
 871         SIVAL(msg,16,e->private_options);
 872         SIVAL(msg,20,(uint32)e->time.tv_sec);
 873         SIVAL(msg,24,(uint32)e->time.tv_usec);
 874         push_file_id_24(msg+28, &e->id);
 875         SIVAL(msg,52,e->share_file_id);
 876         SIVAL(msg,56,e->uid);
 877         SSVAL(msg,60,e->flags);
 878 #ifdef CLUSTER_SUPPORT
 879         SIVAL(msg,62,e->pid.vnn);
 880 #endif
 881 }
 882
 883 /****************************************************************************
 884  De-linearize an internal oplock break message to a share mode entry struct.
 885 ****************************************************************************/
 886
 887 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 888 {
 889         e->pid.pid = (pid_t)IVAL(msg,0);
 890         e->op_mid = SVAL(msg,4);
 891         e->op_type = SVAL(msg,6);
 892         e->access_mask = IVAL(msg,8);
 893         e->share_access = IVAL(msg,12);
 894         e->private_options = IVAL(msg,16);
 895         e->time.tv_sec = (time_t)IVAL(msg,20);
 896         e->time.tv_usec = (int)IVAL(msg,24);
 897         pull_file_id_24(msg+28, &e->id);
 898         e->share_file_id = (unsigned long)IVAL(msg,52);
 899         e->uid = (uint32)IVAL(msg,56);
 900         e->flags = (uint16)SVAL(msg,60);
 901 #ifdef CLUSTER_SUPPORT
 902         e->pid.vnn = IVAL(msg,62);
 903 #endif
 904 }
 905
 906 /****************************************************************************
 907  Setup oplocks for this process.
 908 ****************************************************************************/
 909
 910 bool init_oplocks(struct messaging_context *msg_ctx)
 911 {
 912         DEBUG(3,("init_oplocks: initializing messages.\n"));
 913
 914         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_REQUEST,
 915                            process_oplock_break_message);
 916         messaging_register(msg_ctx, NULL, MSG_SMB_ASYNC_LEVEL2_BREAK,
 917                            process_oplock_async_level2_break_message);
 918         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_RESPONSE,
 919                            process_oplock_break_response);
 920         messaging_register(msg_ctx, NULL, MSG_SMB_KERNEL_BREAK,
 921                            process_kernel_oplock_break);
 922         messaging_register(msg_ctx, NULL, MSG_SMB_OPEN_RETRY,
 923                            process_open_retry_message);
 924
 925         if (lp_kernel_oplocks()) {
 926 #if HAVE_KERNEL_OPLOCKS_IRIX
 927                 koplocks = irix_init_kernel_oplocks(talloc_autofree_context());
 928 #elif HAVE_KERNEL_OPLOCKS_LINUX
 929                 koplocks = linux_init_kernel_oplocks(talloc_autofree_context());
 930 #elif HAVE_ONEFS
 931                 koplocks = onefs_init_kernel_oplocks(talloc_autofree_context());
 932 #endif
 933         }
 934
 935         return True;
 936 }