source/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
  25 /* Current number of oplocks we have outstanding. */
  26 static int32 exclusive_oplocks_open = 0;
  27 static int32 level_II_oplocks_open = 0;
  28 bool global_client_failed_oplock_break = False;
  29
  30 extern uint32 global_client_caps;
  31
  32 static struct kernel_oplocks *koplocks;
  33
  34 /****************************************************************************
  35  Get the number of current exclusive oplocks.
  36 ****************************************************************************/
  37
  38 int32 get_number_of_exclusive_open_oplocks(void)
  39 {
  40   return exclusive_oplocks_open;
  41 }
  42
  43 /****************************************************************************
  44  Return True if an oplock message is pending.
  45 ****************************************************************************/
  46
  47 bool oplock_message_waiting(fd_set *fds)
  48 {
  49         if (koplocks && koplocks->msg_waiting(fds)) {
  50                 return True;
  51         }
  52
  53         return False;
  54 }
  55
  56 /****************************************************************************
  57  Find out if there are any kernel oplock messages waiting and process them
  58  if so. pfds is the fd_set from the main select loop (which contains any
  59  kernel oplock fd if that's what the system uses (IRIX). If may be NULL if
  60  we're calling this in a shutting down state.
  61 ****************************************************************************/
  62
  63 void process_kernel_oplocks(struct messaging_context *msg_ctx, fd_set *pfds)
  64 {
  65         /*
  66          * We need to check for kernel oplocks before going into the select
  67          * here, as the EINTR generated by the linux kernel oplock may have
  68          * already been eaten. JRA.
  69          */
  70
  71         if (!koplocks) {
  72                 return;
  73         }
  74
  75         while (koplocks->msg_waiting(pfds)) {
  76                 files_struct *fsp;
  77                 char msg[MSG_SMB_KERNEL_BREAK_SIZE];
  78
  79                 fsp = koplocks->receive_message(pfds);
  80
  81                 if (fsp == NULL) {
  82                         DEBUG(3, ("Kernel oplock message announced, but none "
  83                                   "received\n"));
  84                         return;
  85                 }
  86
  87                 /* Put the kernel break info into the message. */
  88                 push_file_id_16(msg, &fsp->file_id);
  89                 SIVAL(msg,16,fsp->fh->gen_id);
  90
  91                 /* Don't need to be root here as we're only ever
  92                    sending to ourselves. */
  93
  94                 messaging_send_buf(msg_ctx, procid_self(),
  95                                    MSG_SMB_KERNEL_BREAK,
  96                                    (uint8 *)&msg, MSG_SMB_KERNEL_BREAK_SIZE);
  97         }
  98 }
  99
 100 /****************************************************************************
 101  Attempt to set an oplock on a file. Always succeeds if kernel oplocks are
 102  disabled (just sets flags). Returns True if oplock set.
 103 ****************************************************************************/
 104
 105 bool set_file_oplock(files_struct *fsp, int oplock_type)
 106 {
 107         if ((fsp->oplock_type != NO_OPLOCK) &&
 108             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 109             koplocks &&
 110             !koplocks->set_oplock(fsp, oplock_type)) {
 111                 return False;
 112         }
 113
 114         fsp->oplock_type = oplock_type;
 115         fsp->sent_oplock_break = NO_BREAK_SENT;
 116         if (oplock_type == LEVEL_II_OPLOCK) {
 117                 level_II_oplocks_open++;
 118         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 119                 exclusive_oplocks_open++;
 120         }
 121
 122         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
 123                     "tv_sec = %x, tv_usec = %x\n",
 124                  fsp->fsp_name, file_id_string_tos(&fsp->file_id),
 125                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
 126                  (int)fsp->open_time.tv_usec ));
 127
 128         return True;
 129 }
 130
 131 /****************************************************************************
 132  Attempt to release an oplock on a file. Decrements oplock count.
 133 ****************************************************************************/
 134
 135 void release_file_oplock(files_struct *fsp)
 136 {
 137         if ((fsp->oplock_type != NO_OPLOCK) &&
 138             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 139             koplocks) {
 140                 koplocks->release_oplock(fsp);
 141         }
 142
 143         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 144                 level_II_oplocks_open--;
 145         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 146                 exclusive_oplocks_open--;
 147         }
 148
 149         SMB_ASSERT(exclusive_oplocks_open>=0);
 150         SMB_ASSERT(level_II_oplocks_open>=0);
 151
 152         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 153                 /* This doesn't matter for close. */
 154                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 155         } else {
 156                 fsp->oplock_type = NO_OPLOCK;
 157         }
 158         fsp->sent_oplock_break = NO_BREAK_SENT;
 159
 160         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 161
 162         TALLOC_FREE(fsp->oplock_timeout);
 163 }
 164
 165 /****************************************************************************
 166  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 167 ****************************************************************************/
 168
 169 static void downgrade_file_oplock(files_struct *fsp)
 170 {
 171         if (koplocks) {
 172                 koplocks->release_oplock(fsp);
 173         }
 174         fsp->oplock_type = LEVEL_II_OPLOCK;
 175         exclusive_oplocks_open--;
 176         level_II_oplocks_open++;
 177         fsp->sent_oplock_break = NO_BREAK_SENT;
 178 }
 179
 180 /****************************************************************************
 181  Remove a file oplock. Copes with level II and exclusive.
 182  Locks then unlocks the share mode lock. Client can decide to go directly
 183  to none even if a "break-to-level II" was sent.
 184 ****************************************************************************/
 185
 186 bool remove_oplock(files_struct *fsp)
 187 {
 188         bool ret;
 189         struct share_mode_lock *lck;
 190
 191         /* Remove the oplock flag from the sharemode. */
 192         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 193                                   NULL);
 194         if (lck == NULL) {
 195                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 196                          "file %s\n", fsp->fsp_name ));
 197                 return False;
 198         }
 199         ret = remove_share_oplock(lck, fsp);
 200         if (!ret) {
 201                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 202                          "file %s fnum %d, %s\n",
 203                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 204         }
 205         release_file_oplock(fsp);
 206         TALLOC_FREE(lck);
 207         return ret;
 208 }
 209
 210 /*
 211  * Deal with a reply when a break-to-level II was sent.
 212  */
 213 bool downgrade_oplock(files_struct *fsp)
 214 {
 215         bool ret;
 216         struct share_mode_lock *lck;
 217
 218         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 219                                   NULL);
 220         if (lck == NULL) {
 221                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 222                          "file %s\n", fsp->fsp_name ));
 223                 return False;
 224         }
 225         ret = downgrade_share_oplock(lck, fsp);
 226         if (!ret) {
 227                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 228                          "for file %s fnum %d, file_id %s\n",
 229                          fsp->fsp_name, fsp->fnum, file_id_string_tos(&fsp->file_id)));
 230         }
 231
 232         downgrade_file_oplock(fsp);
 233         TALLOC_FREE(lck);
 234         return ret;
 235 }
 236
 237 /****************************************************************************
 238  Return the fd (if any) used for receiving oplock notifications.
 239 ****************************************************************************/
 240
 241 int oplock_notify_fd(void)
 242 {
 243         if (koplocks) {
 244                 int fd = koplocks->notification_fd;
 245                 if (fd < 0 || fd >= FD_SETSIZE) {
 246                         return -1;
 247                 }
 248         }
 249
 250         return -1;
 251 }
 252
 253 /****************************************************************************
 254  Set up an oplock break message.
 255 ****************************************************************************/
 256
 257 static char *new_break_smb_message(TALLOC_CTX *mem_ctx,
 258                                    files_struct *fsp, uint8 cmd)
 259 {
 260         char *result = TALLOC_ARRAY(mem_ctx, char, smb_size + 8*2 + 0);
 261
 262         if (result == NULL) {
 263                 DEBUG(0, ("talloc failed\n"));
 264                 return NULL;
 265         }
 266
 267         memset(result,'\0',smb_size);
 268         srv_set_message(result,8,0,true);
 269         SCVAL(result,smb_com,SMBlockingX);
 270         SSVAL(result,smb_tid,fsp->conn->cnum);
 271         SSVAL(result,smb_pid,0xFFFF);
 272         SSVAL(result,smb_uid,0);
 273         SSVAL(result,smb_mid,0xFFFF);
 274         SCVAL(result,smb_vwv0,0xFF);
 275         SSVAL(result,smb_vwv2,fsp->fnum);
 276         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 277         SCVAL(result,smb_vwv3+1,cmd);
 278         return result;
 279 }
 280
 281 /****************************************************************************
 282  Function to do the waiting before sending a local break.
 283 ****************************************************************************/
 284
 285 static void wait_before_sending_break(void)
 286 {
 287         long wait_time = (long)lp_oplock_break_wait_time();
 288
 289         if (wait_time) {
 290                 smb_msleep(wait_time);
 291         }
 292 }
 293
 294 /****************************************************************************
 295  Ensure that we have a valid oplock.
 296 ****************************************************************************/
 297
 298 static files_struct *initial_break_processing(struct file_id id, unsigned long file_id)
 299 {
 300         files_struct *fsp = NULL;
 301
 302         if( DEBUGLVL( 3 ) ) {
 303                 dbgtext( "initial_break_processing: called for %s/%u\n",
 304                          file_id_string_tos(&id), (int)file_id);
 305                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 306                         exclusive_oplocks_open, level_II_oplocks_open );
 307         }
 308
 309         /*
 310          * We need to search the file open table for the
 311          * entry containing this dev and inode, and ensure
 312          * we have an oplock on it.
 313          */
 314
 315         fsp = file_find_dif(id, file_id);
 316
 317         if(fsp == NULL) {
 318                 /* The file could have been closed in the meantime - return success. */
 319                 if( DEBUGLVL( 3 ) ) {
 320                         dbgtext( "initial_break_processing: cannot find open file with " );
 321                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 322                         dbgtext( "allowing break to succeed.\n" );
 323                 }
 324                 return NULL;
 325         }
 326
 327         /* Ensure we have an oplock on the file */
 328
 329         /*
 330          * There is a potential race condition in that an oplock could
 331          * have been broken due to another udp request, and yet there are
 332          * still oplock break messages being sent in the udp message
 333          * queue for this file. So return true if we don't have an oplock,
 334          * as we may have just freed it.
 335          */
 336
 337         if(fsp->oplock_type == NO_OPLOCK) {
 338                 if( DEBUGLVL( 3 ) ) {
 339                         dbgtext( "initial_break_processing: file %s ", fsp->fsp_name );
 340                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 341                                  file_id_string_tos(&id), fsp->fh->gen_id );
 342                         dbgtext( "Allowing break to succeed regardless.\n" );
 343                 }
 344                 return NULL;
 345         }
 346
 347         return fsp;
 348 }
 349
 350 static void oplock_timeout_handler(struct event_context *ctx,
 351                                    struct timed_event *te,
 352                                    struct timeval now,
 353                                    void *private_data)
 354 {
 355         files_struct *fsp = (files_struct *)private_data;
 356
 357         /* Remove the timed event handler. */
 358         TALLOC_FREE(fsp->oplock_timeout);
 359         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n", fsp->fsp_name));
 360         global_client_failed_oplock_break = True;
 361         remove_oplock(fsp);
 362         reply_to_oplock_break_requests(fsp);
 363 }
 364
 365 /*******************************************************************
 366  Add a timeout handler waiting for the client reply.
 367 *******************************************************************/
 368
 369 static void add_oplock_timeout_handler(files_struct *fsp)
 370 {
 371         if (fsp->oplock_timeout != NULL) {
 372                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 373                           "around\n"));
 374         }
 375
 376         fsp->oplock_timeout =
 377                 event_add_timed(smbd_event_context(), NULL,
 378                                 timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 379                                 oplock_timeout_handler, fsp);
 380
 381         if (fsp->oplock_timeout == NULL) {
 382                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 383         }
 384 }
 385
 386 /*******************************************************************
 387  This handles the case of a write triggering a break to none
 388  message on a level2 oplock.
 389  When we get this message we may be in any of three states :
 390  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 391  the client for LEVEL2.
 392 *******************************************************************/
 393
 394 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 395                                                       void *private_data,
 396                                                       uint32_t msg_type,
 397                                                       struct server_id src,
 398                                                       DATA_BLOB *data)
 399 {
 400         struct share_mode_entry msg;
 401         files_struct *fsp;
 402         char *break_msg;
 403         bool sign_state;
 404
 405         if (data->data == NULL) {
 406                 DEBUG(0, ("Got NULL buffer\n"));
 407                 return;
 408         }
 409
 410         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 411                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 412                 return;
 413         }
 414
 415         /* De-linearize incoming message. */
 416         message_to_share_mode_entry(&msg, (char *)data->data);
 417
 418         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 419                    "%s/%lu\n", procid_str(debug_ctx(), &src),
 420                    file_id_string_tos(&msg.id), msg.share_file_id));
 421
 422         fsp = initial_break_processing(msg.id, msg.share_file_id);
 423
 424         if (fsp == NULL) {
 425                 /* We hit a race here. Break messages are sent, and before we
 426                  * get to process this message, we have closed the file.
 427                  * No need to reply as this is an async message. */
 428                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 429                 return;
 430         }
 431
 432         if (fsp->oplock_type == NO_OPLOCK) {
 433                 /* We already got a "break to none" message and we've handled it.
 434                  * just ignore. */
 435                 DEBUG(3, ("process_oplock_async_level2_break_message: already broken to none, ignoring.\n"));
 436                 return;
 437         }
 438
 439         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 440                 /* Don't tell the client, just downgrade. */
 441                 DEBUG(3, ("process_oplock_async_level2_break_message: downgrading fake level 2 oplock.\n"));
 442                 remove_oplock(fsp);
 443                 return;
 444         }
 445
 446         /* Ensure we're really at level2 state. */
 447         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 448
 449         DEBUG(10,("process_oplock_async_level2_break_message: sending break to "
 450                 "none message for fid %d, file %s\n",
 451                 fsp->fnum,
 452                 fsp->fsp_name));
 453
 454         /* Now send a break to none message to our client. */
 455
 456         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 457         if (break_msg == NULL) {
 458                 exit_server("Could not talloc break_msg\n");
 459         }
 460
 461         /* Need to wait before sending a break message if we sent ourselves this message. */
 462         if (procid_is_me(&src)) {
 463                 wait_before_sending_break();
 464         }
 465
 466         /* Save the server smb signing state. */
 467         sign_state = srv_oplock_set_signing(False);
 468
 469         show_msg(break_msg);
 470         if (!srv_send_smb(smbd_server_fd(),
 471                         break_msg,
 472                         IS_CONN_ENCRYPTED(fsp->conn))) {
 473                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 474         }
 475
 476         /* Restore the sign state to what it was. */
 477         srv_oplock_set_signing(sign_state);
 478
 479         TALLOC_FREE(break_msg);
 480
 481         /* Async level2 request, don't send a reply, just remove the oplock. */
 482         remove_oplock(fsp);
 483 }
 484
 485 /*******************************************************************
 486  This handles the generic oplock break message from another smbd.
 487 *******************************************************************/
 488
 489 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 490                                          void *private_data,
 491                                          uint32_t msg_type,
 492                                          struct server_id src,
 493                                          DATA_BLOB *data)
 494 {
 495         struct share_mode_entry msg;
 496         files_struct *fsp;
 497         char *break_msg;
 498         bool break_to_level2 = False;
 499         bool sign_state;
 500
 501         if (data->data == NULL) {
 502                 DEBUG(0, ("Got NULL buffer\n"));
 503                 return;
 504         }
 505
 506         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 507                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 508                 return;
 509         }
 510
 511         /* De-linearize incoming message. */
 512         message_to_share_mode_entry(&msg, (char *)data->data);
 513
 514         DEBUG(10, ("Got oplock break message from pid %s: %s/%lu\n",
 515                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 516                    msg.share_file_id));
 517
 518         fsp = initial_break_processing(msg.id, msg.share_file_id);
 519
 520         if (fsp == NULL) {
 521                 /* a We hit race here. Break messages are sent, and before we
 522                  * get to process this message, we have closed the file. Reply
 523                  * with 'ok, oplock broken' */
 524                 DEBUG(3, ("Did not find fsp\n"));
 525
 526                 /* We just send the same message back. */
 527                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 528                                    (uint8 *)data->data,
 529                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 530                 return;
 531         }
 532
 533         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 534                 /* Remember we have to inform the requesting PID when the
 535                  * client replies */
 536                 msg.pid = src;
 537                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 538                              &fsp->pending_break_messages,
 539                              &fsp->num_pending_break_messages);
 540                 return;
 541         }
 542
 543         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 544             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 545                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 546                           file_id_string_tos(&fsp->file_id),
 547                           fsp->fsp_name));
 548                 /* We just send the same message back. */
 549                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 550                                    (uint8 *)data->data,
 551                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 552                 return;
 553         }
 554
 555         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 556             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 557             !koplocks && /* NOTE: we force levelII off for kernel oplocks -
 558                           * this will change when it is supported */
 559             lp_level2_oplocks(SNUM(fsp->conn))) {
 560                 break_to_level2 = True;
 561         }
 562
 563         break_msg = new_break_smb_message(NULL, fsp, break_to_level2 ?
 564                                           OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 565         if (break_msg == NULL) {
 566                 exit_server("Could not talloc break_msg\n");
 567         }
 568
 569         /* Need to wait before sending a break message if we sent ourselves this message. */
 570         if (procid_is_me(&src)) {
 571                 wait_before_sending_break();
 572         }
 573
 574         /* Save the server smb signing state. */
 575         sign_state = srv_oplock_set_signing(False);
 576
 577         show_msg(break_msg);
 578         if (!srv_send_smb(smbd_server_fd(),
 579                         break_msg,
 580                         IS_CONN_ENCRYPTED(fsp->conn))) {
 581                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 582         }
 583
 584         /* Restore the sign state to what it was. */
 585         srv_oplock_set_signing(sign_state);
 586
 587         TALLOC_FREE(break_msg);
 588
 589         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 590
 591         msg.pid = src;
 592         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 593                      &fsp->pending_break_messages,
 594                      &fsp->num_pending_break_messages);
 595
 596         add_oplock_timeout_handler(fsp);
 597 }
 598
 599 /*******************************************************************
 600  This handles the kernel oplock break message.
 601 *******************************************************************/
 602
 603 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 604                                         void *private_data,
 605                                         uint32_t msg_type,
 606                                         struct server_id src,
 607                                         DATA_BLOB *data)
 608 {
 609         struct file_id id;
 610         unsigned long file_id;
 611         files_struct *fsp;
 612         char *break_msg;
 613         bool sign_state;
 614
 615         if (data->data == NULL) {
 616                 DEBUG(0, ("Got NULL buffer\n"));
 617                 return;
 618         }
 619
 620         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 621                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 622                 return;
 623         }
 624
 625         /* Pull the data from the message. */
 626         pull_file_id_16((char *)data->data, &id);
 627         file_id = (unsigned long)IVAL(data->data, 16);
 628
 629         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 630                    procid_str(debug_ctx(), &src), file_id_string_tos(&id),
 631                    (unsigned int)file_id));
 632
 633         fsp = initial_break_processing(id, file_id);
 634
 635         if (fsp == NULL) {
 636                 DEBUG(3, ("Got a kernel oplock break message for a file "
 637                           "I don't know about\n"));
 638                 return;
 639         }
 640
 641         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 642                 /* This is ok, kernel oplocks come in completely async */
 643                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 644                           "break reply\n"));
 645                 return;
 646         }
 647
 648         break_msg = new_break_smb_message(NULL, fsp, OPLOCKLEVEL_NONE);
 649         if (break_msg == NULL) {
 650                 exit_server("Could not talloc break_msg\n");
 651         }
 652
 653         /* Save the server smb signing state. */
 654         sign_state = srv_oplock_set_signing(False);
 655
 656         show_msg(break_msg);
 657         if (!srv_send_smb(smbd_server_fd(),
 658                         break_msg,
 659                         IS_CONN_ENCRYPTED(fsp->conn))) {
 660                 exit_server_cleanly("oplock_break: srv_send_smb failed.");
 661         }
 662
 663         /* Restore the sign state to what it was. */
 664         srv_oplock_set_signing(sign_state);
 665
 666         TALLOC_FREE(break_msg);
 667
 668         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 669
 670         add_oplock_timeout_handler(fsp);
 671 }
 672
 673 void reply_to_oplock_break_requests(files_struct *fsp)
 674 {
 675         int i;
 676
 677         for (i=0; i<fsp->num_pending_break_messages; i++) {
 678                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 679                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 680
 681                 share_mode_entry_to_message(msg, e);
 682
 683                 messaging_send_buf(smbd_messaging_context(), e->pid,
 684                                    MSG_SMB_BREAK_RESPONSE,
 685                                    (uint8 *)msg,
 686                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 687         }
 688
 689         SAFE_FREE(fsp->pending_break_messages);
 690         fsp->num_pending_break_messages = 0;
 691         if (fsp->oplock_timeout != NULL) {
 692                 /* Remove the timed event handler. */
 693                 TALLOC_FREE(fsp->oplock_timeout);
 694                 fsp->oplock_timeout = NULL;
 695         }
 696         return;
 697 }
 698
 699 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 700                                           void *private_data,
 701                                           uint32_t msg_type,
 702                                           struct server_id src,
 703                                           DATA_BLOB *data)
 704 {
 705         struct share_mode_entry msg;
 706
 707         if (data->data == NULL) {
 708                 DEBUG(0, ("Got NULL buffer\n"));
 709                 return;
 710         }
 711
 712         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 713                 DEBUG(0, ("Got invalid msg len %u\n",
 714                           (unsigned int)data->length));
 715                 return;
 716         }
 717
 718         /* De-linearize incoming message. */
 719         message_to_share_mode_entry(&msg, (char *)data->data);
 720
 721         DEBUG(10, ("Got oplock break response from pid %s: %s/%lu mid %u\n",
 722                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 723                    msg.share_file_id, (unsigned int)msg.op_mid));
 724
 725         /* Here's the hack from open.c, store the mid in the 'port' field */
 726         schedule_deferred_open_smb_message(msg.op_mid);
 727 }
 728
 729 static void process_open_retry_message(struct messaging_context *msg_ctx,
 730                                        void *private_data,
 731                                        uint32_t msg_type,
 732                                        struct server_id src,
 733                                        DATA_BLOB *data)
 734 {
 735         struct share_mode_entry msg;
 736
 737         if (data->data == NULL) {
 738                 DEBUG(0, ("Got NULL buffer\n"));
 739                 return;
 740         }
 741
 742         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 743                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 744                 return;
 745         }
 746
 747         /* De-linearize incoming message. */
 748         message_to_share_mode_entry(&msg, (char *)data->data);
 749
 750         DEBUG(10, ("Got open retry msg from pid %s: %s mid %u\n",
 751                    procid_str(debug_ctx(), &src), file_id_string_tos(&msg.id),
 752                    (unsigned int)msg.op_mid));
 753
 754         schedule_deferred_open_smb_message(msg.op_mid);
 755 }
 756
 757 /****************************************************************************
 758  This function is called on any file modification or lock request. If a file
 759  is level 2 oplocked then it must tell all other level 2 holders to break to
 760  none.
 761 ****************************************************************************/
 762
 763 void release_level_2_oplocks_on_change(files_struct *fsp)
 764 {
 765         int i;
 766         struct share_mode_lock *lck;
 767
 768         /*
 769          * If this file is level II oplocked then we need
 770          * to grab the shared memory lock and inform all
 771          * other files with a level II lock that they need
 772          * to flush their read caches. We keep the lock over
 773          * the shared memory area whilst doing this.
 774          */
 775
 776         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 777                 return;
 778
 779         lck = get_share_mode_lock(talloc_tos(), fsp->file_id, NULL, NULL,
 780                                   NULL);
 781         if (lck == NULL) {
 782                 DEBUG(0,("release_level_2_oplocks_on_change: failed to lock "
 783                          "share mode entry for file %s.\n", fsp->fsp_name ));
 784                 return;
 785         }
 786
 787         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 788                   lck->num_share_modes ));
 789
 790         for(i = 0; i < lck->num_share_modes; i++) {
 791                 struct share_mode_entry *share_entry = &lck->share_modes[i];
 792                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 793
 794                 if (!is_valid_share_mode_entry(share_entry)) {
 795                         continue;
 796                 }
 797
 798                 /*
 799                  * As there could have been multiple writes waiting at the
 800                  * lock_share_entry gate we may not be the first to
 801                  * enter. Hence the state of the op_types in the share mode
 802                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 803                  * oplock. It will do no harm to re-send break messages to
 804                  * those smbd's that are still waiting their turn to remove
 805                  * their LEVEL_II state, and also no harm to ignore existing
 806                  * NO_OPLOCK states. JRA.
 807                  */
 808
 809                 DEBUG(10,("release_level_2_oplocks_on_change: "
 810                           "share_entry[%i]->op_type == %d\n",
 811                           i, share_entry->op_type ));
 812
 813                 if (share_entry->op_type == NO_OPLOCK) {
 814                         continue;
 815                 }
 816
 817                 /* Paranoia .... */
 818                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 819                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 820                                  "share mode entry %d is an exlusive "
 821                                  "oplock !\n", i ));
 822                         TALLOC_FREE(lck);
 823                         abort();
 824                 }
 825
 826                 share_mode_entry_to_message(msg, share_entry);
 827
 828                 /*
 829                  * Deal with a race condition when breaking level2
 830                  * oplocks. Don't send all the messages and release
 831                  * the lock, this allows someone else to come in and
 832                  * get a level2 lock before any of the messages are
 833                  * processed, and thus miss getting a break message.
 834                  * Ensure at least one entry (the one we're breaking)
 835                  * is processed immediately under the lock and becomes
 836                  * set as NO_OPLOCK to stop any waiter getting a level2.
 837                  * Bugid #5979.
 838                  */
 839
 840                 if (procid_is_me(&share_entry->pid)) {
 841                         DATA_BLOB blob = data_blob_const(msg,
 842                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 843                         process_oplock_async_level2_break_message(smbd_messaging_context(),
 844                                                 NULL,
 845                                                 MSG_SMB_ASYNC_LEVEL2_BREAK,
 846                                                 share_entry->pid,
 847                                                 &blob);
 848                 } else {
 849                         messaging_send_buf(smbd_messaging_context(),
 850                                         share_entry->pid,
 851                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 852                                         (uint8 *)msg,
 853                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 854                 }
 855         }
 856
 857         /* We let the message receivers handle removing the oplock state
 858            in the share mode lock db. */
 859
 860         TALLOC_FREE(lck);
 861 }
 862
 863 /****************************************************************************
 864  Linearize a share mode entry struct to an internal oplock break message.
 865 ****************************************************************************/
 866
 867 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 868 {
 869         SIVAL(msg,0,(uint32)e->pid.pid);
 870         SSVAL(msg,4,e->op_mid);
 871         SSVAL(msg,6,e->op_type);
 872         SIVAL(msg,8,e->access_mask);
 873         SIVAL(msg,12,e->share_access);
 874         SIVAL(msg,16,e->private_options);
 875         SIVAL(msg,20,(uint32)e->time.tv_sec);
 876         SIVAL(msg,24,(uint32)e->time.tv_usec);
 877         push_file_id_16(msg+28, &e->id);
 878         SIVAL(msg,44,e->share_file_id);
 879         SIVAL(msg,48,e->uid);
 880         SSVAL(msg,52,e->flags);
 881 #ifdef CLUSTER_SUPPORT
 882         SIVAL(msg,54,e->pid.vnn);
 883 #endif
 884 }
 885
 886 /****************************************************************************
 887  De-linearize an internal oplock break message to a share mode entry struct.
 888 ****************************************************************************/
 889
 890 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 891 {
 892         e->pid.pid = (pid_t)IVAL(msg,0);
 893         e->op_mid = SVAL(msg,4);
 894         e->op_type = SVAL(msg,6);
 895         e->access_mask = IVAL(msg,8);
 896         e->share_access = IVAL(msg,12);
 897         e->private_options = IVAL(msg,16);
 898         e->time.tv_sec = (time_t)IVAL(msg,20);
 899         e->time.tv_usec = (int)IVAL(msg,24);
 900         pull_file_id_16(msg+28, &e->id);
 901         e->share_file_id = (unsigned long)IVAL(msg,44);
 902         e->uid = (uint32)IVAL(msg,48);
 903         e->flags = (uint16)SVAL(msg,52);
 904 #ifdef CLUSTER_SUPPORT
 905         e->pid.vnn = IVAL(msg,54);
 906 #endif
 907 }
 908
 909 /****************************************************************************
 910  Setup oplocks for this process.
 911 ****************************************************************************/
 912
 913 bool init_oplocks(struct messaging_context *msg_ctx)
 914 {
 915         DEBUG(3,("init_oplocks: initializing messages.\n"));
 916
 917         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_REQUEST,
 918                            process_oplock_break_message);
 919         messaging_register(msg_ctx, NULL, MSG_SMB_ASYNC_LEVEL2_BREAK,
 920                            process_oplock_async_level2_break_message);
 921         messaging_register(msg_ctx, NULL, MSG_SMB_BREAK_RESPONSE,
 922                            process_oplock_break_response);
 923         messaging_register(msg_ctx, NULL, MSG_SMB_KERNEL_BREAK,
 924                            process_kernel_oplock_break);
 925         messaging_register(msg_ctx, NULL, MSG_SMB_OPEN_RETRY,
 926                            process_open_retry_message);
 927
 928         if (lp_kernel_oplocks()) {
 929 #if HAVE_KERNEL_OPLOCKS_IRIX
 930                 koplocks = irix_init_kernel_oplocks();
 931 #elif HAVE_KERNEL_OPLOCKS_LINUX
 932                 koplocks = linux_init_kernel_oplocks();
 933 #endif
 934         }
 935
 936         return True;
 937 }