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/smbd.h"
  25 #include "smbd/globals.h"
  26 #include "messages.h"
  27 #include "../librpc/gen_ndr/open_files.h"
  28
  29 /*
  30  * helper function used by the kernel oplock backends to post the break message
  31  */
  32 void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
  33 {
  34         uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
  35
  36         /* Put the kernel break info into the message. */
  37         push_file_id_24((char *)msg, &fsp->file_id);
  38         SIVAL(msg,24,fsp->fh->gen_id);
  39
  40         /* Don't need to be root here as we're only ever
  41            sending to ourselves. */
  42
  43         messaging_send_buf(msg_ctx, messaging_server_id(msg_ctx),
  44                            MSG_SMB_KERNEL_BREAK,
  45                            msg, MSG_SMB_KERNEL_BREAK_SIZE);
  46 }
  47
  48 /****************************************************************************
  49  Attempt to set an oplock on a file. Succeeds if kernel oplocks are
  50  disabled (just sets flags) and no byte-range locks in the file. Returns True
  51  if oplock set.
  52 ****************************************************************************/
  53
  54 bool set_file_oplock(files_struct *fsp, int oplock_type)
  55 {
  56         struct smbd_server_connection *sconn = fsp->conn->sconn;
  57         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
  58         bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
  59
  60         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
  61                 if (use_kernel &&
  62                     !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) {
  63                         DEBUG(10, ("Refusing level2 oplock, kernel oplocks "
  64                                    "don't support them\n"));
  65                         return false;
  66                 }
  67         }
  68
  69         if ((fsp->oplock_type != NO_OPLOCK) &&
  70             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
  71             use_kernel &&
  72             !koplocks->ops->set_oplock(koplocks, fsp, oplock_type)) {
  73                 return False;
  74         }
  75
  76         fsp->oplock_type = oplock_type;
  77         fsp->sent_oplock_break = NO_BREAK_SENT;
  78         if (oplock_type == LEVEL_II_OPLOCK) {
  79                 sconn->oplocks.level_II_open++;
  80         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  81                 sconn->oplocks.exclusive_open++;
  82         }
  83
  84         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  85                     "tv_sec = %x, tv_usec = %x\n",
  86                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  87                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  88                  (int)fsp->open_time.tv_usec ));
  89
  90         return True;
  91 }
  92
  93 /****************************************************************************
  94  Attempt to release an oplock on a file. Decrements oplock count.
  95 ****************************************************************************/
  96
  97 void release_file_oplock(files_struct *fsp)
  98 {
  99         struct smbd_server_connection *sconn = fsp->conn->sconn;
 100         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 101
 102         if ((fsp->oplock_type != NO_OPLOCK) &&
 103             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 104             koplocks) {
 105                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 106         }
 107
 108         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 109                 sconn->oplocks.level_II_open--;
 110         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 111                 sconn->oplocks.exclusive_open--;
 112         }
 113
 114         SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
 115         SMB_ASSERT(sconn->oplocks.level_II_open>=0);
 116
 117         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 118                 /* This doesn't matter for close. */
 119                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 120         } else {
 121                 fsp->oplock_type = NO_OPLOCK;
 122         }
 123         fsp->sent_oplock_break = NO_BREAK_SENT;
 124
 125         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 126         delete_write_cache(fsp);
 127
 128         TALLOC_FREE(fsp->oplock_timeout);
 129 }
 130
 131 /****************************************************************************
 132  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 133 ****************************************************************************/
 134
 135 static void downgrade_file_oplock(files_struct *fsp)
 136 {
 137         struct smbd_server_connection *sconn = fsp->conn->sconn;
 138         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 139
 140         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 141                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 142                 return;
 143         }
 144
 145         if (koplocks) {
 146                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 147         }
 148         fsp->oplock_type = LEVEL_II_OPLOCK;
 149         sconn->oplocks.exclusive_open--;
 150         sconn->oplocks.level_II_open++;
 151         fsp->sent_oplock_break = NO_BREAK_SENT;
 152 }
 153
 154 /****************************************************************************
 155  Remove a file oplock. Copes with level II and exclusive.
 156  Locks then unlocks the share mode lock. Client can decide to go directly
 157  to none even if a "break-to-level II" was sent.
 158 ****************************************************************************/
 159
 160 bool remove_oplock(files_struct *fsp)
 161 {
 162         bool ret;
 163         struct share_mode_lock *lck;
 164
 165         /* Remove the oplock flag from the sharemode. */
 166         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 167         if (lck == NULL) {
 168                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 169                          "file %s\n", fsp_str_dbg(fsp)));
 170                 return False;
 171         }
 172         ret = remove_share_oplock(lck, fsp);
 173         if (!ret) {
 174                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 175                          "file %s fnum %d, %s\n",
 176                          fsp_str_dbg(fsp), fsp->fnum,
 177                          file_id_string_tos(&fsp->file_id)));
 178         }
 179         release_file_oplock(fsp);
 180         TALLOC_FREE(lck);
 181         return ret;
 182 }
 183
 184 /*
 185  * Deal with a reply when a break-to-level II was sent.
 186  */
 187 bool downgrade_oplock(files_struct *fsp)
 188 {
 189         bool ret;
 190         struct share_mode_lock *lck;
 191
 192         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 193         if (lck == NULL) {
 194                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 195                          "file %s\n", fsp_str_dbg(fsp)));
 196                 return False;
 197         }
 198         ret = downgrade_share_oplock(lck, fsp);
 199         if (!ret) {
 200                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 201                          "for file %s fnum %d, file_id %s\n",
 202                          fsp_str_dbg(fsp), fsp->fnum,
 203                          file_id_string_tos(&fsp->file_id)));
 204         }
 205
 206         downgrade_file_oplock(fsp);
 207         TALLOC_FREE(lck);
 208         return ret;
 209 }
 210
 211 /*
 212  * Some kernel oplock implementations handle the notification themselves.
 213  */
 214 bool should_notify_deferred_opens(struct smbd_server_connection *sconn)
 215 {
 216         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 217         return !(koplocks &&
 218                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 219 }
 220
 221 /****************************************************************************
 222  Set up an oplock break message.
 223 ****************************************************************************/
 224
 225 static char *new_break_message_smb1(TALLOC_CTX *mem_ctx,
 226                                    files_struct *fsp, int cmd)
 227 {
 228         char *result = talloc_array(mem_ctx, char, smb_size + 8*2 + 0);
 229
 230         if (result == NULL) {
 231                 DEBUG(0, ("talloc failed\n"));
 232                 return NULL;
 233         }
 234
 235         memset(result,'\0',smb_size);
 236         srv_set_message(result,8,0,true);
 237         SCVAL(result,smb_com,SMBlockingX);
 238         SSVAL(result,smb_tid,fsp->conn->cnum);
 239         SSVAL(result,smb_pid,0xFFFF);
 240         SSVAL(result,smb_uid,0);
 241         SSVAL(result,smb_mid,0xFFFF);
 242         SCVAL(result,smb_vwv0,0xFF);
 243         SSVAL(result,smb_vwv2,fsp->fnum);
 244         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 245         SCVAL(result,smb_vwv3+1,cmd);
 246         return result;
 247 }
 248
 249 /****************************************************************************
 250  Function to do the waiting before sending a local break.
 251 ****************************************************************************/
 252
 253 static void wait_before_sending_break(void)
 254 {
 255         long wait_time = (long)lp_oplock_break_wait_time();
 256
 257         if (wait_time) {
 258                 smb_msleep(wait_time);
 259         }
 260 }
 261
 262 /****************************************************************************
 263  Ensure that we have a valid oplock.
 264 ****************************************************************************/
 265
 266 static files_struct *initial_break_processing(
 267         struct smbd_server_connection *sconn, struct file_id id,
 268         unsigned long file_id)
 269 {
 270         files_struct *fsp = NULL;
 271
 272         if( DEBUGLVL( 3 ) ) {
 273                 dbgtext( "initial_break_processing: called for %s/%u\n",
 274                          file_id_string_tos(&id), (int)file_id);
 275                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 276                         sconn->oplocks.exclusive_open,
 277                         sconn->oplocks.level_II_open);
 278         }
 279
 280         /*
 281          * We need to search the file open table for the
 282          * entry containing this dev and inode, and ensure
 283          * we have an oplock on it.
 284          */
 285
 286         fsp = file_find_dif(sconn, id, file_id);
 287
 288         if(fsp == NULL) {
 289                 /* The file could have been closed in the meantime - return success. */
 290                 if( DEBUGLVL( 3 ) ) {
 291                         dbgtext( "initial_break_processing: cannot find open file with " );
 292                         dbgtext( "file_id %s gen_id = %lu", file_id_string_tos(&id), file_id);
 293                         dbgtext( "allowing break to succeed.\n" );
 294                 }
 295                 return NULL;
 296         }
 297
 298         /* Ensure we have an oplock on the file */
 299
 300         /*
 301          * There is a potential race condition in that an oplock could
 302          * have been broken due to another udp request, and yet there are
 303          * still oplock break messages being sent in the udp message
 304          * queue for this file. So return true if we don't have an oplock,
 305          * as we may have just freed it.
 306          */
 307
 308         if(fsp->oplock_type == NO_OPLOCK) {
 309                 if( DEBUGLVL( 3 ) ) {
 310                         dbgtext( "initial_break_processing: file %s ",
 311                                  fsp_str_dbg(fsp));
 312                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 313                                  file_id_string_tos(&id), fsp->fh->gen_id );
 314                         dbgtext( "Allowing break to succeed regardless.\n" );
 315                 }
 316                 return NULL;
 317         }
 318
 319         return fsp;
 320 }
 321
 322 static void oplock_timeout_handler(struct event_context *ctx,
 323                                    struct timed_event *te,
 324                                    struct timeval now,
 325                                    void *private_data)
 326 {
 327         files_struct *fsp = (files_struct *)private_data;
 328
 329         /* Remove the timed event handler. */
 330         TALLOC_FREE(fsp->oplock_timeout);
 331         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 332                   fsp_str_dbg(fsp)));
 333         remove_oplock(fsp);
 334         reply_to_oplock_break_requests(fsp);
 335 }
 336
 337 /*******************************************************************
 338  Add a timeout handler waiting for the client reply.
 339 *******************************************************************/
 340
 341 static void add_oplock_timeout_handler(files_struct *fsp)
 342 {
 343         struct smbd_server_connection *sconn = fsp->conn->sconn;
 344         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 345
 346         /*
 347          * If kernel oplocks already notifies smbds when an oplock break times
 348          * out, just return.
 349          */
 350         if (koplocks &&
 351             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 352                 return;
 353         }
 354
 355         if (fsp->oplock_timeout != NULL) {
 356                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 357                           "around\n"));
 358         }
 359
 360         fsp->oplock_timeout =
 361                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 362                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 363                                  oplock_timeout_handler, fsp);
 364
 365         if (fsp->oplock_timeout == NULL) {
 366                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 367         }
 368 }
 369
 370 static void send_break_message_smb1(files_struct *fsp, int level)
 371 {
 372         char *break_msg = new_break_message_smb1(talloc_tos(),
 373                                         fsp,
 374                                         level);
 375         if (break_msg == NULL) {
 376                 exit_server("Could not talloc break_msg\n");
 377         }
 378
 379         show_msg(break_msg);
 380         if (!srv_send_smb(fsp->conn->sconn,
 381                         break_msg, false, 0,
 382                         IS_CONN_ENCRYPTED(fsp->conn),
 383                         NULL)) {
 384                 exit_server_cleanly("send_break_message_smb1: "
 385                         "srv_send_smb failed.");
 386         }
 387
 388         TALLOC_FREE(break_msg);
 389 }
 390
 391 void break_level2_to_none_async(files_struct *fsp)
 392 {
 393         struct smbd_server_connection *sconn = fsp->conn->sconn;
 394
 395         if (fsp->oplock_type == NO_OPLOCK) {
 396                 /* We already got a "break to none" message and we've handled
 397                  * it.  just ignore. */
 398                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 399                           "broken to none, ignoring.\n"));
 400                 return;
 401         }
 402
 403         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 404                 /* Don't tell the client, just downgrade. */
 405                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 406                           "downgrading fake level 2 oplock.\n"));
 407                 remove_oplock(fsp);
 408                 return;
 409         }
 410
 411         /* Ensure we're really at level2 state. */
 412         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 413
 414         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 415                   "to none message for fid %d, file %s\n", fsp->fnum,
 416                   fsp_str_dbg(fsp)));
 417
 418         /* Now send a break to none message to our client. */
 419         if (sconn->using_smb2) {
 420                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 421         } else {
 422                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 423         }
 424
 425         /* Async level2 request, don't send a reply, just remove the oplock. */
 426         remove_oplock(fsp);
 427 }
 428
 429 /*******************************************************************
 430  This handles the case of a write triggering a break to none
 431  message on a level2 oplock.
 432  When we get this message we may be in any of three states :
 433  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 434  the client for LEVEL2.
 435 *******************************************************************/
 436
 437 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 438                                                       void *private_data,
 439                                                       uint32_t msg_type,
 440                                                       struct server_id src,
 441                                                       DATA_BLOB *data)
 442 {
 443         struct share_mode_entry msg;
 444         files_struct *fsp;
 445         struct smbd_server_connection *sconn =
 446                 talloc_get_type_abort(private_data,
 447                 struct smbd_server_connection);
 448
 449         if (data->data == NULL) {
 450                 DEBUG(0, ("Got NULL buffer\n"));
 451                 return;
 452         }
 453
 454         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 455                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 456                 return;
 457         }
 458
 459         /* De-linearize incoming message. */
 460         message_to_share_mode_entry(&msg, (char *)data->data);
 461
 462         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 463                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 464                    file_id_string_tos(&msg.id),
 465                    (unsigned long long)msg.share_file_id));
 466
 467         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 468
 469         if (fsp == NULL) {
 470                 /* We hit a race here. Break messages are sent, and before we
 471                  * get to process this message, we have closed the file.
 472                  * No need to reply as this is an async message. */
 473                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 474                 return;
 475         }
 476
 477         break_level2_to_none_async(fsp);
 478 }
 479
 480 /*******************************************************************
 481  This handles the generic oplock break message from another smbd.
 482 *******************************************************************/
 483
 484 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 485                                          void *private_data,
 486                                          uint32_t msg_type,
 487                                          struct server_id src,
 488                                          DATA_BLOB *data)
 489 {
 490         struct share_mode_entry msg;
 491         files_struct *fsp;
 492         bool break_to_level2 = False;
 493         bool use_kernel;
 494         struct smbd_server_connection *sconn =
 495                 talloc_get_type_abort(private_data,
 496                 struct smbd_server_connection);
 497         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 498
 499         if (data->data == NULL) {
 500                 DEBUG(0, ("Got NULL buffer\n"));
 501                 return;
 502         }
 503
 504         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 505                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 506                 return;
 507         }
 508
 509         /* De-linearize incoming message. */
 510         message_to_share_mode_entry(&msg, (char *)data->data);
 511
 512         DEBUG(10, ("Got oplock break message from pid %s: %s/%llu\n",
 513                    server_id_str(talloc_tos(), &src),
 514                    file_id_string_tos(&msg.id),
 515                    (unsigned long long)msg.share_file_id));
 516
 517         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 518
 519         if (fsp == NULL) {
 520                 /* We hit a race here. Break messages are sent, and before we
 521                  * get to process this message, we have closed the file. Reply
 522                  * with 'ok, oplock broken' */
 523                 DEBUG(3, ("Did not find fsp\n"));
 524
 525                 /* We just send the same message back. */
 526                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 527                                    (uint8 *)data->data,
 528                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 529                 return;
 530         }
 531
 532         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 533                 /* Remember we have to inform the requesting PID when the
 534                  * client replies */
 535                 msg.pid = src;
 536                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 537                              &fsp->pending_break_messages,
 538                              &fsp->num_pending_break_messages);
 539                 return;
 540         }
 541
 542         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 543             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 544                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 545                           file_id_string_tos(&fsp->file_id),
 546                           fsp_str_dbg(fsp)));
 547                 /* We just send the same message back. */
 548                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 549                                    (uint8 *)data->data,
 550                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 551                 return;
 552         }
 553
 554         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 555
 556         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 557             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 558             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 559             lp_level2_oplocks(SNUM(fsp->conn))) {
 560                 break_to_level2 = True;
 561         }
 562
 563         /* Need to wait before sending a break
 564            message if we sent ourselves this message. */
 565         if (procid_is_me(&src)) {
 566                 wait_before_sending_break();
 567         }
 568
 569         if (sconn->using_smb2) {
 570                 send_break_message_smb2(fsp, break_to_level2 ?
 571                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 572         } else {
 573                 send_break_message_smb1(fsp, break_to_level2 ?
 574                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 575         }
 576
 577         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 578
 579         msg.pid = src;
 580         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 581                      &fsp->pending_break_messages,
 582                      &fsp->num_pending_break_messages);
 583
 584         add_oplock_timeout_handler(fsp);
 585 }
 586
 587 /*******************************************************************
 588  This handles the kernel oplock break message.
 589 *******************************************************************/
 590
 591 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 592                                         void *private_data,
 593                                         uint32_t msg_type,
 594                                         struct server_id src,
 595                                         DATA_BLOB *data)
 596 {
 597         struct file_id id;
 598         unsigned long file_id;
 599         files_struct *fsp;
 600         struct smbd_server_connection *sconn =
 601                 talloc_get_type_abort(private_data,
 602                 struct smbd_server_connection);
 603
 604         if (data->data == NULL) {
 605                 DEBUG(0, ("Got NULL buffer\n"));
 606                 return;
 607         }
 608
 609         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 610                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 611                 return;
 612         }
 613
 614         /* Pull the data from the message. */
 615         pull_file_id_24((char *)data->data, &id);
 616         file_id = (unsigned long)IVAL(data->data, 24);
 617
 618         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 619                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 620                    (unsigned int)file_id));
 621
 622         fsp = initial_break_processing(sconn, id, file_id);
 623
 624         if (fsp == NULL) {
 625                 DEBUG(3, ("Got a kernel oplock break message for a file "
 626                           "I don't know about\n"));
 627                 return;
 628         }
 629
 630         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 631                 /* This is ok, kernel oplocks come in completely async */
 632                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 633                           "break reply\n"));
 634                 return;
 635         }
 636
 637         if (sconn->using_smb2) {
 638                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 639         } else {
 640                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 641         }
 642
 643         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 644
 645         add_oplock_timeout_handler(fsp);
 646 }
 647
 648 void reply_to_oplock_break_requests(files_struct *fsp)
 649 {
 650         struct smbd_server_connection *sconn = fsp->conn->sconn;
 651         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 652         int i;
 653
 654         /*
 655          * If kernel oplocks already notifies smbds when oplocks are
 656          * broken/removed, just return.
 657          */
 658         if (koplocks &&
 659             (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
 660                 return;
 661         }
 662
 663         for (i=0; i<fsp->num_pending_break_messages; i++) {
 664                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 665                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 666
 667                 share_mode_entry_to_message(msg, e);
 668
 669                 messaging_send_buf(fsp->conn->sconn->msg_ctx, e->pid,
 670                                    MSG_SMB_BREAK_RESPONSE,
 671                                    (uint8 *)msg,
 672                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 673         }
 674
 675         SAFE_FREE(fsp->pending_break_messages);
 676         fsp->num_pending_break_messages = 0;
 677         TALLOC_FREE(fsp->oplock_timeout);
 678         return;
 679 }
 680
 681 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 682                                           void *private_data,
 683                                           uint32_t msg_type,
 684                                           struct server_id src,
 685                                           DATA_BLOB *data)
 686 {
 687         struct share_mode_entry msg;
 688         struct smbd_server_connection *sconn =
 689                 talloc_get_type_abort(private_data,
 690                 struct smbd_server_connection);
 691
 692         if (data->data == NULL) {
 693                 DEBUG(0, ("Got NULL buffer\n"));
 694                 return;
 695         }
 696
 697         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 698                 DEBUG(0, ("Got invalid msg len %u\n",
 699                           (unsigned int)data->length));
 700                 return;
 701         }
 702
 703         /* De-linearize incoming message. */
 704         message_to_share_mode_entry(&msg, (char *)data->data);
 705
 706         DEBUG(10, ("Got oplock break response from pid %s: %s/%llu mid %llu\n",
 707                    server_id_str(talloc_tos(), &src),
 708                    file_id_string_tos(&msg.id),
 709                    (unsigned long long)msg.share_file_id,
 710                    (unsigned long long)msg.op_mid));
 711
 712         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 713 }
 714
 715 static void process_open_retry_message(struct messaging_context *msg_ctx,
 716                                        void *private_data,
 717                                        uint32_t msg_type,
 718                                        struct server_id src,
 719                                        DATA_BLOB *data)
 720 {
 721         struct share_mode_entry msg;
 722         struct smbd_server_connection *sconn =
 723                 talloc_get_type_abort(private_data,
 724                 struct smbd_server_connection);
 725
 726         if (data->data == NULL) {
 727                 DEBUG(0, ("Got NULL buffer\n"));
 728                 return;
 729         }
 730
 731         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 732                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 733                 return;
 734         }
 735
 736         /* De-linearize incoming message. */
 737         message_to_share_mode_entry(&msg, (char *)data->data);
 738
 739         DEBUG(10, ("Got open retry msg from pid %s: %s mid %llu\n",
 740                    server_id_str(talloc_tos(), &src), file_id_string_tos(&msg.id),
 741                    (unsigned long long)msg.op_mid));
 742
 743         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 744 }
 745
 746 struct break_to_none_state {
 747         struct smbd_server_connection *sconn;
 748         struct file_id id;
 749 };
 750 static void do_break_to_none(struct tevent_req *req);
 751
 752 /****************************************************************************
 753  This function is called on any file modification or lock request. If a file
 754  is level 2 oplocked then it must tell all other level 2 holders to break to
 755  none.
 756 ****************************************************************************/
 757
 758 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 759                                               enum level2_contention_type type)
 760 {
 761         struct smbd_server_connection *sconn = fsp->conn->sconn;
 762         struct tevent_req *req;
 763         struct break_to_none_state *state;
 764
 765         /*
 766          * If this file is level II oplocked then we need
 767          * to grab the shared memory lock and inform all
 768          * other files with a level II lock that they need
 769          * to flush their read caches. We keep the lock over
 770          * the shared memory area whilst doing this.
 771          */
 772
 773         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 774                 return;
 775
 776         /*
 777          * When we get here we might have a brlock entry locked. Also
 778          * locking the share mode entry would violate the locking
 779          * order. Breaking level2 oplocks to none is asynchronous
 780          * anyway, so we postpone this into an immediate timed event.
 781          */
 782
 783         state = talloc(sconn, struct break_to_none_state);
 784         if (state == NULL) {
 785                 DEBUG(1, ("talloc failed\n"));
 786                 return;
 787         }
 788         state->sconn = sconn;
 789         state->id = fsp->file_id;
 790
 791         req = tevent_wakeup_send(state, sconn->ev_ctx, timeval_set(0, 0));
 792         if (req == NULL) {
 793                 DEBUG(1, ("tevent_wakeup_send failed\n"));
 794                 TALLOC_FREE(state);
 795                 return;
 796         }
 797         tevent_req_set_callback(req, do_break_to_none, state);
 798         return;
 799 }
 800
 801 static void do_break_to_none(struct tevent_req *req)
 802 {
 803         struct break_to_none_state *state = tevent_req_callback_data(
 804                 req, struct break_to_none_state);
 805         bool ret;
 806         int i;
 807         struct share_mode_lock *lck;
 808
 809         ret = tevent_wakeup_recv(req);
 810         TALLOC_FREE(req);
 811         if (!ret) {
 812                 DEBUG(1, ("tevent_wakeup_recv failed\n"));
 813                 goto done;
 814         }
 815         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 816         if (lck == NULL) {
 817                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 818                           "share mode entry for file %s.\n",
 819                           file_id_string_tos(&state->id)));
 820                 goto done;
 821         }
 822
 823         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 824                   lck->data->num_share_modes ));
 825
 826         for(i = 0; i < lck->data->num_share_modes; i++) {
 827                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 828                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 829
 830                 if (!is_valid_share_mode_entry(share_entry)) {
 831                         continue;
 832                 }
 833
 834                 /*
 835                  * As there could have been multiple writes waiting at the
 836                  * lock_share_entry gate we may not be the first to
 837                  * enter. Hence the state of the op_types in the share mode
 838                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 839                  * oplock. It will do no harm to re-send break messages to
 840                  * those smbd's that are still waiting their turn to remove
 841                  * their LEVEL_II state, and also no harm to ignore existing
 842                  * NO_OPLOCK states. JRA.
 843                  */
 844
 845                 DEBUG(10,("release_level_2_oplocks_on_change: "
 846                           "share_entry[%i]->op_type == %d\n",
 847                           i, share_entry->op_type ));
 848
 849                 if (share_entry->op_type == NO_OPLOCK) {
 850                         continue;
 851                 }
 852
 853                 /* Paranoia .... */
 854                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 855                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 856                                  "share mode entry %d is an exlusive "
 857                                  "oplock !\n", i ));
 858                         TALLOC_FREE(lck);
 859                         abort();
 860                 }
 861
 862                 share_mode_entry_to_message(msg, share_entry);
 863
 864                 /*
 865                  * Deal with a race condition when breaking level2
 866                  * oplocks. Don't send all the messages and release
 867                  * the lock, this allows someone else to come in and
 868                  * get a level2 lock before any of the messages are
 869                  * processed, and thus miss getting a break message.
 870                  * Ensure at least one entry (the one we're breaking)
 871                  * is processed immediately under the lock and becomes
 872                  * set as NO_OPLOCK to stop any waiter getting a level2.
 873                  * Bugid #5980.
 874                  */
 875
 876                 if (procid_is_me(&share_entry->pid)) {
 877                         struct files_struct *cur_fsp =
 878                                 initial_break_processing(state->sconn,
 879                                         share_entry->id,
 880                                         share_entry->share_file_id);
 881                         wait_before_sending_break();
 882                         if (cur_fsp != NULL) {
 883                                 break_level2_to_none_async(cur_fsp);
 884                         } else {
 885                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 886                                 "Did not find fsp, ignoring\n"));
 887                         }
 888                 } else {
 889                         messaging_send_buf(state->sconn->msg_ctx,
 890                                         share_entry->pid,
 891                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 892                                         (uint8 *)msg,
 893                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 894                 }
 895         }
 896
 897         /* We let the message receivers handle removing the oplock state
 898            in the share mode lock db. */
 899
 900         TALLOC_FREE(lck);
 901 done:
 902         TALLOC_FREE(state);
 903         return;
 904 }
 905
 906 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 907                                   enum level2_contention_type type)
 908 {
 909         struct smbd_server_connection *sconn = fsp->conn->sconn;
 910         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 911
 912         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 913                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 914                 return;
 915         }
 916
 917         contend_level2_oplocks_begin_default(fsp, type);
 918 }
 919
 920 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 921                                 enum level2_contention_type type)
 922 {
 923         struct smbd_server_connection *sconn = fsp->conn->sconn;
 924         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 925
 926         /* Only kernel oplocks implement this so far */
 927         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 928                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 929         }
 930 }
 931
 932 /****************************************************************************
 933  Linearize a share mode entry struct to an internal oplock break message.
 934 ****************************************************************************/
 935
 936 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 937 {
 938         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 939         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 940         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 941         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 942         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 943         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 944         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 945         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 946         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 947         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 948         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 949         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 950         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 951         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 952 }
 953
 954 /****************************************************************************
 955  De-linearize an internal oplock break message to a share mode entry struct.
 956 ****************************************************************************/
 957
 958 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 959 {
 960         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 961         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 962         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 963         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 964         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 965         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 966         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 967         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 968         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 969         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 970         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 971         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 972         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 973         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 974 }
 975
 976 /****************************************************************************
 977  Setup oplocks for this process.
 978 ****************************************************************************/
 979
 980 bool init_oplocks(struct smbd_server_connection *sconn)
 981 {
 982         DEBUG(3,("init_oplocks: initializing messages.\n"));
 983
 984         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 985                            process_oplock_break_message);
 986         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 987                            process_oplock_async_level2_break_message);
 988         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_RESPONSE,
 989                            process_oplock_break_response);
 990         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 991                            process_kernel_oplock_break);
 992         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_OPEN_RETRY,
 993                            process_open_retry_message);
 994
 995         return true;
 996 }
 997
 998 void init_kernel_oplocks(struct smbd_server_connection *sconn)
 999 {
1000         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
1001
1002         /* only initialize once */
1003         if (koplocks == NULL) {
1004 #if HAVE_KERNEL_OPLOCKS_IRIX
1005                 koplocks = irix_init_kernel_oplocks(sconn);
1006 #elif HAVE_KERNEL_OPLOCKS_LINUX
1007                 koplocks = linux_init_kernel_oplocks(sconn);
1008 #endif
1009                 sconn->oplocks.kernel_ops = koplocks;
1010         }
1011 }