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 NTSTATUS 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 NT_STATUS_NOT_SUPPORTED;
  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         {
  74                 return map_nt_error_from_unix(errno);
  75         }
  76
  77         fsp->oplock_type = oplock_type;
  78         fsp->sent_oplock_break = NO_BREAK_SENT;
  79         if (oplock_type == LEVEL_II_OPLOCK) {
  80                 sconn->oplocks.level_II_open++;
  81         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
  82                 sconn->oplocks.exclusive_open++;
  83         }
  84
  85         DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
  86                     "tv_sec = %x, tv_usec = %x\n",
  87                  fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
  88                  fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
  89                  (int)fsp->open_time.tv_usec ));
  90
  91         return NT_STATUS_OK;
  92 }
  93
  94 /****************************************************************************
  95  Attempt to release an oplock on a file. Decrements oplock count.
  96 ****************************************************************************/
  97
  98 void release_file_oplock(files_struct *fsp)
  99 {
 100         struct smbd_server_connection *sconn = fsp->conn->sconn;
 101         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 102
 103         if ((fsp->oplock_type != NO_OPLOCK) &&
 104             (fsp->oplock_type != FAKE_LEVEL_II_OPLOCK) &&
 105             koplocks) {
 106                 koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
 107         }
 108
 109         if (fsp->oplock_type == LEVEL_II_OPLOCK) {
 110                 sconn->oplocks.level_II_open--;
 111         } else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 112                 sconn->oplocks.exclusive_open--;
 113         }
 114
 115         SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
 116         SMB_ASSERT(sconn->oplocks.level_II_open>=0);
 117
 118         if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 119                 /* This doesn't matter for close. */
 120                 fsp->oplock_type = FAKE_LEVEL_II_OPLOCK;
 121         } else {
 122                 fsp->oplock_type = NO_OPLOCK;
 123         }
 124         fsp->sent_oplock_break = NO_BREAK_SENT;
 125
 126         flush_write_cache(fsp, OPLOCK_RELEASE_FLUSH);
 127         delete_write_cache(fsp);
 128
 129         TALLOC_FREE(fsp->oplock_timeout);
 130 }
 131
 132 /****************************************************************************
 133  Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
 134 ****************************************************************************/
 135
 136 static void downgrade_file_oplock(files_struct *fsp)
 137 {
 138         struct smbd_server_connection *sconn = fsp->conn->sconn;
 139         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 140
 141         if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 142                 DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
 143                 return;
 144         }
 145
 146         if (koplocks) {
 147                 koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
 148         }
 149         fsp->oplock_type = LEVEL_II_OPLOCK;
 150         sconn->oplocks.exclusive_open--;
 151         sconn->oplocks.level_II_open++;
 152         fsp->sent_oplock_break = NO_BREAK_SENT;
 153 }
 154
 155 /****************************************************************************
 156  Remove a file oplock. Copes with level II and exclusive.
 157  Locks then unlocks the share mode lock. Client can decide to go directly
 158  to none even if a "break-to-level II" was sent.
 159 ****************************************************************************/
 160
 161 bool remove_oplock(files_struct *fsp)
 162 {
 163         bool ret;
 164         struct share_mode_lock *lck;
 165
 166         /* Remove the oplock flag from the sharemode. */
 167         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 168         if (lck == NULL) {
 169                 DEBUG(0,("remove_oplock: failed to lock share entry for "
 170                          "file %s\n", fsp_str_dbg(fsp)));
 171                 return False;
 172         }
 173         ret = remove_share_oplock(lck, fsp);
 174         if (!ret) {
 175                 DEBUG(0,("remove_oplock: failed to remove share oplock for "
 176                          "file %s, %s, %s\n",
 177                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 178                          file_id_string_tos(&fsp->file_id)));
 179         }
 180         release_file_oplock(fsp);
 181         TALLOC_FREE(lck);
 182         return ret;
 183 }
 184
 185 /*
 186  * Deal with a reply when a break-to-level II was sent.
 187  */
 188 bool downgrade_oplock(files_struct *fsp)
 189 {
 190         bool ret;
 191         struct share_mode_lock *lck;
 192
 193         lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
 194         if (lck == NULL) {
 195                 DEBUG(0,("downgrade_oplock: failed to lock share entry for "
 196                          "file %s\n", fsp_str_dbg(fsp)));
 197                 return False;
 198         }
 199         ret = downgrade_share_oplock(lck, fsp);
 200         if (!ret) {
 201                 DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
 202                          "for file %s, %s, file_id %s\n",
 203                          fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
 204                          file_id_string_tos(&fsp->file_id)));
 205         }
 206
 207         downgrade_file_oplock(fsp);
 208         TALLOC_FREE(lck);
 209         return ret;
 210 }
 211
 212 /*
 213  * Some kernel oplock implementations handle the notification themselves.
 214  */
 215 bool should_notify_deferred_opens(struct smbd_server_connection *sconn)
 216 {
 217         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 218         return !(koplocks &&
 219                 (koplocks->flags & KOPLOCKS_DEFERRED_OPEN_NOTIFICATION));
 220 }
 221
 222 /****************************************************************************
 223  Set up an oplock break message.
 224 ****************************************************************************/
 225
 226 static char *new_break_message_smb1(TALLOC_CTX *mem_ctx,
 227                                    files_struct *fsp, int cmd)
 228 {
 229         char *result = talloc_array(mem_ctx, char, smb_size + 8*2 + 0);
 230
 231         if (result == NULL) {
 232                 DEBUG(0, ("talloc failed\n"));
 233                 return NULL;
 234         }
 235
 236         memset(result,'\0',smb_size);
 237         srv_set_message(result,8,0,true);
 238         SCVAL(result,smb_com,SMBlockingX);
 239         SSVAL(result,smb_tid,fsp->conn->cnum);
 240         SSVAL(result,smb_pid,0xFFFF);
 241         SSVAL(result,smb_uid,0);
 242         SSVAL(result,smb_mid,0xFFFF);
 243         SCVAL(result,smb_vwv0,0xFF);
 244         SSVAL(result,smb_vwv2,fsp->fnum);
 245         SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
 246         SCVAL(result,smb_vwv3+1,cmd);
 247         return result;
 248 }
 249
 250 /****************************************************************************
 251  Function to do the waiting before sending a local break.
 252 ****************************************************************************/
 253
 254 static void wait_before_sending_break(void)
 255 {
 256         long wait_time = (long)lp_oplock_break_wait_time();
 257
 258         if (wait_time) {
 259                 smb_msleep(wait_time);
 260         }
 261 }
 262
 263 /****************************************************************************
 264  Ensure that we have a valid oplock.
 265 ****************************************************************************/
 266
 267 static files_struct *initial_break_processing(
 268         struct smbd_server_connection *sconn, struct file_id id,
 269         unsigned long file_id)
 270 {
 271         files_struct *fsp = NULL;
 272
 273         if( DEBUGLVL( 3 ) ) {
 274                 dbgtext( "initial_break_processing: called for %s/%u\n",
 275                          file_id_string_tos(&id), (int)file_id);
 276                 dbgtext( "Current oplocks_open (exclusive = %d, levelII = %d)\n",
 277                         sconn->oplocks.exclusive_open,
 278                         sconn->oplocks.level_II_open);
 279         }
 280
 281         /*
 282          * We need to search the file open table for the
 283          * entry containing this dev and inode, and ensure
 284          * we have an oplock on it.
 285          */
 286
 287         fsp = file_find_dif(sconn, id, file_id);
 288
 289         if(fsp == NULL) {
 290                 /* The file could have been closed in the meantime - return success. */
 291                 if( DEBUGLVL( 3 ) ) {
 292                         dbgtext( "initial_break_processing: cannot find open file with " );
 293                         dbgtext( "file_id %s gen_id = %lu, ", file_id_string_tos(&id), file_id);
 294                         dbgtext( "allowing break to succeed.\n" );
 295                 }
 296                 return NULL;
 297         }
 298
 299         /* Ensure we have an oplock on the file */
 300
 301         /*
 302          * There is a potential race condition in that an oplock could
 303          * have been broken due to another udp request, and yet there are
 304          * still oplock break messages being sent in the udp message
 305          * queue for this file. So return true if we don't have an oplock,
 306          * as we may have just freed it.
 307          */
 308
 309         if(fsp->oplock_type == NO_OPLOCK) {
 310                 if( DEBUGLVL( 3 ) ) {
 311                         dbgtext( "initial_break_processing: file %s ",
 312                                  fsp_str_dbg(fsp));
 313                         dbgtext( "(file_id = %s gen_id = %lu) has no oplock.\n",
 314                                  file_id_string_tos(&id), fsp->fh->gen_id );
 315                         dbgtext( "Allowing break to succeed regardless.\n" );
 316                 }
 317                 return NULL;
 318         }
 319
 320         return fsp;
 321 }
 322
 323 static void oplock_timeout_handler(struct tevent_context *ctx,
 324                                    struct tevent_timer *te,
 325                                    struct timeval now,
 326                                    void *private_data)
 327 {
 328         files_struct *fsp = (files_struct *)private_data;
 329
 330         /* Remove the timed event handler. */
 331         TALLOC_FREE(fsp->oplock_timeout);
 332         DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
 333                   fsp_str_dbg(fsp)));
 334         remove_oplock(fsp);
 335         reply_to_oplock_break_requests(fsp);
 336 }
 337
 338 /*******************************************************************
 339  Add a timeout handler waiting for the client reply.
 340 *******************************************************************/
 341
 342 static void add_oplock_timeout_handler(files_struct *fsp)
 343 {
 344         struct smbd_server_connection *sconn = fsp->conn->sconn;
 345         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 346
 347         /*
 348          * If kernel oplocks already notifies smbds when an oplock break times
 349          * out, just return.
 350          */
 351         if (koplocks &&
 352             (koplocks->flags & KOPLOCKS_TIMEOUT_NOTIFICATION)) {
 353                 return;
 354         }
 355
 356         if (fsp->oplock_timeout != NULL) {
 357                 DEBUG(0, ("Logic problem -- have an oplock event hanging "
 358                           "around\n"));
 359         }
 360
 361         fsp->oplock_timeout =
 362                 tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
 363                                  timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
 364                                  oplock_timeout_handler, fsp);
 365
 366         if (fsp->oplock_timeout == NULL) {
 367                 DEBUG(0, ("Could not add oplock timeout handler\n"));
 368         }
 369 }
 370
 371 static void send_break_message_smb1(files_struct *fsp, int level)
 372 {
 373         char *break_msg = new_break_message_smb1(talloc_tos(),
 374                                         fsp,
 375                                         level);
 376         if (break_msg == NULL) {
 377                 exit_server("Could not talloc break_msg\n");
 378         }
 379
 380         show_msg(break_msg);
 381         if (!srv_send_smb(fsp->conn->sconn,
 382                         break_msg, false, 0,
 383                         IS_CONN_ENCRYPTED(fsp->conn),
 384                         NULL)) {
 385                 exit_server_cleanly("send_break_message_smb1: "
 386                         "srv_send_smb failed.");
 387         }
 388
 389         TALLOC_FREE(break_msg);
 390 }
 391
 392 void break_level2_to_none_async(files_struct *fsp)
 393 {
 394         struct smbd_server_connection *sconn = fsp->conn->sconn;
 395
 396         if (fsp->oplock_type == NO_OPLOCK) {
 397                 /* We already got a "break to none" message and we've handled
 398                  * it.  just ignore. */
 399                 DEBUG(3, ("process_oplock_async_level2_break_message: already "
 400                           "broken to none, ignoring.\n"));
 401                 return;
 402         }
 403
 404         if (fsp->oplock_type == FAKE_LEVEL_II_OPLOCK) {
 405                 /* Don't tell the client, just downgrade. */
 406                 DEBUG(3, ("process_oplock_async_level2_break_message: "
 407                           "downgrading fake level 2 oplock.\n"));
 408                 remove_oplock(fsp);
 409                 return;
 410         }
 411
 412         /* Ensure we're really at level2 state. */
 413         SMB_ASSERT(fsp->oplock_type == LEVEL_II_OPLOCK);
 414
 415         DEBUG(10,("process_oplock_async_level2_break_message: sending break "
 416                   "to none message for %s, file %s\n", fsp_fnum_dbg(fsp),
 417                   fsp_str_dbg(fsp)));
 418
 419         /* Now send a break to none message to our client. */
 420         if (sconn->using_smb2) {
 421                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 422         } else {
 423                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 424         }
 425
 426         /* Async level2 request, don't send a reply, just remove the oplock. */
 427         remove_oplock(fsp);
 428 }
 429
 430 /*******************************************************************
 431  This handles the case of a write triggering a break to none
 432  message on a level2 oplock.
 433  When we get this message we may be in any of three states :
 434  NO_OPLOCK, LEVEL_II, FAKE_LEVEL2. We only send a message to
 435  the client for LEVEL2.
 436 *******************************************************************/
 437
 438 static void process_oplock_async_level2_break_message(struct messaging_context *msg_ctx,
 439                                                       void *private_data,
 440                                                       uint32_t msg_type,
 441                                                       struct server_id src,
 442                                                       DATA_BLOB *data)
 443 {
 444         struct share_mode_entry msg;
 445         files_struct *fsp;
 446         struct smbd_server_connection *sconn =
 447                 talloc_get_type_abort(private_data,
 448                 struct smbd_server_connection);
 449
 450         if (data->data == NULL) {
 451                 DEBUG(0, ("Got NULL buffer\n"));
 452                 return;
 453         }
 454
 455         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 456                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 457                 return;
 458         }
 459
 460         /* De-linearize incoming message. */
 461         message_to_share_mode_entry(&msg, (char *)data->data);
 462
 463         DEBUG(10, ("Got oplock async level 2 break message from pid %s: "
 464                    "%s/%llu\n", server_id_str(talloc_tos(), &src),
 465                    file_id_string_tos(&msg.id),
 466                    (unsigned long long)msg.share_file_id));
 467
 468         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 469
 470         if (fsp == NULL) {
 471                 /* We hit a race here. Break messages are sent, and before we
 472                  * get to process this message, we have closed the file.
 473                  * No need to reply as this is an async message. */
 474                 DEBUG(3, ("process_oplock_async_level2_break_message: Did not find fsp, ignoring\n"));
 475                 return;
 476         }
 477
 478         break_level2_to_none_async(fsp);
 479 }
 480
 481 /*******************************************************************
 482  This handles the generic oplock break message from another smbd.
 483 *******************************************************************/
 484
 485 static void process_oplock_break_message(struct messaging_context *msg_ctx,
 486                                          void *private_data,
 487                                          uint32_t msg_type,
 488                                          struct server_id src,
 489                                          DATA_BLOB *data)
 490 {
 491         struct share_mode_entry msg;
 492         files_struct *fsp;
 493         bool break_to_level2 = False;
 494         bool use_kernel;
 495         struct smbd_server_connection *sconn =
 496                 talloc_get_type_abort(private_data,
 497                 struct smbd_server_connection);
 498         struct server_id self = messaging_server_id(sconn->msg_ctx);
 499         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 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/%llu\n",
 515                    server_id_str(talloc_tos(), &src),
 516                    file_id_string_tos(&msg.id),
 517                    (unsigned long long)msg.share_file_id));
 518
 519         fsp = initial_break_processing(sconn, msg.id, msg.share_file_id);
 520
 521         if (fsp == NULL) {
 522                 /* We hit a race here. Break messages are sent, and before we
 523                  * get to process this message, we have closed the file. Reply
 524                  * with 'ok, oplock broken' */
 525                 DEBUG(3, ("Did not find fsp\n"));
 526
 527                 /* We just send the same message back. */
 528                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 529                                    (uint8 *)data->data,
 530                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 531                 return;
 532         }
 533
 534         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 535                 /* Remember we have to inform the requesting PID when the
 536                  * client replies */
 537                 msg.pid = src;
 538                 ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 539                              &fsp->pending_break_messages,
 540                              &fsp->num_pending_break_messages);
 541                 return;
 542         }
 543
 544         if (EXCLUSIVE_OPLOCK_TYPE(msg.op_type) &&
 545             !EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
 546                 DEBUG(3, ("Already downgraded oplock on %s: %s\n",
 547                           file_id_string_tos(&fsp->file_id),
 548                           fsp_str_dbg(fsp)));
 549                 /* We just send the same message back. */
 550                 messaging_send_buf(msg_ctx, src, MSG_SMB_BREAK_RESPONSE,
 551                                    (uint8 *)data->data,
 552                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 553                 return;
 554         }
 555
 556         use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) && koplocks;
 557
 558         if ((global_client_caps & CAP_LEVEL_II_OPLOCKS) &&
 559             !(msg.op_type & FORCE_OPLOCK_BREAK_TO_NONE) &&
 560             !(use_kernel && !(koplocks->flags & KOPLOCKS_LEVEL2_SUPPORTED)) &&
 561             lp_level2_oplocks(SNUM(fsp->conn))) {
 562                 break_to_level2 = True;
 563         }
 564
 565         /* Need to wait before sending a break
 566            message if we sent ourselves this message. */
 567         if (serverid_equal(&self, &src)) {
 568                 wait_before_sending_break();
 569         }
 570
 571         if (sconn->using_smb2) {
 572                 send_break_message_smb2(fsp, break_to_level2 ?
 573                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 574         } else {
 575                 send_break_message_smb1(fsp, break_to_level2 ?
 576                         OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
 577         }
 578
 579         fsp->sent_oplock_break = break_to_level2 ? LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
 580
 581         msg.pid = src;
 582         ADD_TO_ARRAY(NULL, struct share_mode_entry, msg,
 583                      &fsp->pending_break_messages,
 584                      &fsp->num_pending_break_messages);
 585
 586         add_oplock_timeout_handler(fsp);
 587 }
 588
 589 /*******************************************************************
 590  This handles the kernel oplock break message.
 591 *******************************************************************/
 592
 593 static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
 594                                         void *private_data,
 595                                         uint32_t msg_type,
 596                                         struct server_id src,
 597                                         DATA_BLOB *data)
 598 {
 599         struct file_id id;
 600         unsigned long file_id;
 601         files_struct *fsp;
 602         struct smbd_server_connection *sconn =
 603                 talloc_get_type_abort(private_data,
 604                 struct smbd_server_connection);
 605
 606         if (data->data == NULL) {
 607                 DEBUG(0, ("Got NULL buffer\n"));
 608                 return;
 609         }
 610
 611         if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
 612                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 613                 return;
 614         }
 615
 616         /* Pull the data from the message. */
 617         pull_file_id_24((char *)data->data, &id);
 618         file_id = (unsigned long)IVAL(data->data, 24);
 619
 620         DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
 621                    server_id_str(talloc_tos(), &src), file_id_string_tos(&id),
 622                    (unsigned int)file_id));
 623
 624         fsp = initial_break_processing(sconn, id, file_id);
 625
 626         if (fsp == NULL) {
 627                 DEBUG(3, ("Got a kernel oplock break message for a file "
 628                           "I don't know about\n"));
 629                 return;
 630         }
 631
 632         if (fsp->sent_oplock_break != NO_BREAK_SENT) {
 633                 /* This is ok, kernel oplocks come in completely async */
 634                 DEBUG(3, ("Got a kernel oplock request while waiting for a "
 635                           "break reply\n"));
 636                 return;
 637         }
 638
 639         if (sconn->using_smb2) {
 640                 send_break_message_smb2(fsp, OPLOCKLEVEL_NONE);
 641         } else {
 642                 send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
 643         }
 644
 645         fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
 646
 647         add_oplock_timeout_handler(fsp);
 648 }
 649
 650 void reply_to_oplock_break_requests(files_struct *fsp)
 651 {
 652         struct smbd_server_connection *sconn = fsp->conn->sconn;
 653         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 654         int i;
 655
 656         /*
 657          * If kernel oplocks already notifies smbds when oplocks are
 658          * broken/removed, just return.
 659          */
 660         if (koplocks &&
 661             (koplocks->flags & KOPLOCKS_OPLOCK_BROKEN_NOTIFICATION)) {
 662                 return;
 663         }
 664
 665         for (i=0; i<fsp->num_pending_break_messages; i++) {
 666                 struct share_mode_entry *e = &fsp->pending_break_messages[i];
 667                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 668
 669                 share_mode_entry_to_message(msg, e);
 670
 671                 messaging_send_buf(fsp->conn->sconn->msg_ctx, e->pid,
 672                                    MSG_SMB_BREAK_RESPONSE,
 673                                    (uint8 *)msg,
 674                                    MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 675         }
 676
 677         SAFE_FREE(fsp->pending_break_messages);
 678         fsp->num_pending_break_messages = 0;
 679         TALLOC_FREE(fsp->oplock_timeout);
 680         return;
 681 }
 682
 683 static void process_oplock_break_response(struct messaging_context *msg_ctx,
 684                                           void *private_data,
 685                                           uint32_t msg_type,
 686                                           struct server_id src,
 687                                           DATA_BLOB *data)
 688 {
 689         struct share_mode_entry msg;
 690         struct smbd_server_connection *sconn =
 691                 talloc_get_type_abort(private_data,
 692                 struct smbd_server_connection);
 693
 694         if (data->data == NULL) {
 695                 DEBUG(0, ("Got NULL buffer\n"));
 696                 return;
 697         }
 698
 699         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 700                 DEBUG(0, ("Got invalid msg len %u\n",
 701                           (unsigned int)data->length));
 702                 return;
 703         }
 704
 705         /* De-linearize incoming message. */
 706         message_to_share_mode_entry(&msg, (char *)data->data);
 707
 708         DEBUG(10, ("Got oplock break response from pid %s: %s/%llu mid %llu\n",
 709                    server_id_str(talloc_tos(), &src),
 710                    file_id_string_tos(&msg.id),
 711                    (unsigned long long)msg.share_file_id,
 712                    (unsigned long long)msg.op_mid));
 713
 714         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 715 }
 716
 717 static void process_open_retry_message(struct messaging_context *msg_ctx,
 718                                        void *private_data,
 719                                        uint32_t msg_type,
 720                                        struct server_id src,
 721                                        DATA_BLOB *data)
 722 {
 723         struct share_mode_entry msg;
 724         struct smbd_server_connection *sconn =
 725                 talloc_get_type_abort(private_data,
 726                 struct smbd_server_connection);
 727
 728         if (data->data == NULL) {
 729                 DEBUG(0, ("Got NULL buffer\n"));
 730                 return;
 731         }
 732
 733         if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
 734                 DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
 735                 return;
 736         }
 737
 738         /* De-linearize incoming message. */
 739         message_to_share_mode_entry(&msg, (char *)data->data);
 740
 741         DEBUG(10, ("Got open retry msg from pid %s: %s mid %llu\n",
 742                    server_id_str(talloc_tos(), &src), file_id_string_tos(&msg.id),
 743                    (unsigned long long)msg.op_mid));
 744
 745         schedule_deferred_open_message_smb(sconn, msg.op_mid);
 746 }
 747
 748 struct break_to_none_state {
 749         struct smbd_server_connection *sconn;
 750         struct file_id id;
 751 };
 752 static void do_break_to_none(struct tevent_req *req);
 753
 754 /****************************************************************************
 755  This function is called on any file modification or lock request. If a file
 756  is level 2 oplocked then it must tell all other level 2 holders to break to
 757  none.
 758 ****************************************************************************/
 759
 760 static void contend_level2_oplocks_begin_default(files_struct *fsp,
 761                                               enum level2_contention_type type)
 762 {
 763         struct smbd_server_connection *sconn = fsp->conn->sconn;
 764         struct tevent_req *req;
 765         struct break_to_none_state *state;
 766
 767         /*
 768          * If this file is level II oplocked then we need
 769          * to grab the shared memory lock and inform all
 770          * other files with a level II lock that they need
 771          * to flush their read caches. We keep the lock over
 772          * the shared memory area whilst doing this.
 773          */
 774
 775         if (!LEVEL_II_OPLOCK_TYPE(fsp->oplock_type))
 776                 return;
 777
 778         /*
 779          * When we get here we might have a brlock entry locked. Also
 780          * locking the share mode entry would violate the locking
 781          * order. Breaking level2 oplocks to none is asynchronous
 782          * anyway, so we postpone this into an immediate timed event.
 783          */
 784
 785         state = talloc(sconn, struct break_to_none_state);
 786         if (state == NULL) {
 787                 DEBUG(1, ("talloc failed\n"));
 788                 return;
 789         }
 790         state->sconn = sconn;
 791         state->id = fsp->file_id;
 792
 793         req = tevent_wakeup_send(state, sconn->ev_ctx, timeval_set(0, 0));
 794         if (req == NULL) {
 795                 DEBUG(1, ("tevent_wakeup_send failed\n"));
 796                 TALLOC_FREE(state);
 797                 return;
 798         }
 799         tevent_req_set_callback(req, do_break_to_none, state);
 800         return;
 801 }
 802
 803 static void do_break_to_none(struct tevent_req *req)
 804 {
 805         struct break_to_none_state *state = tevent_req_callback_data(
 806                 req, struct break_to_none_state);
 807         struct server_id self = messaging_server_id(state->sconn->msg_ctx);
 808         bool ret;
 809         int i;
 810         struct share_mode_lock *lck;
 811
 812         ret = tevent_wakeup_recv(req);
 813         TALLOC_FREE(req);
 814         if (!ret) {
 815                 DEBUG(1, ("tevent_wakeup_recv failed\n"));
 816                 goto done;
 817         }
 818         lck = get_existing_share_mode_lock(talloc_tos(), state->id);
 819         if (lck == NULL) {
 820                 DEBUG(1, ("release_level_2_oplocks_on_change: failed to lock "
 821                           "share mode entry for file %s.\n",
 822                           file_id_string_tos(&state->id)));
 823                 goto done;
 824         }
 825
 826         DEBUG(10,("release_level_2_oplocks_on_change: num_share_modes = %d\n",
 827                   lck->data->num_share_modes ));
 828
 829         for(i = 0; i < lck->data->num_share_modes; i++) {
 830                 struct share_mode_entry *share_entry = &lck->data->share_modes[i];
 831                 char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
 832
 833                 if (!is_valid_share_mode_entry(share_entry)) {
 834                         continue;
 835                 }
 836
 837                 /*
 838                  * As there could have been multiple writes waiting at the
 839                  * lock_share_entry gate we may not be the first to
 840                  * enter. Hence the state of the op_types in the share mode
 841                  * entries may be partly NO_OPLOCK and partly LEVEL_II or FAKE_LEVEL_II
 842                  * oplock. It will do no harm to re-send break messages to
 843                  * those smbd's that are still waiting their turn to remove
 844                  * their LEVEL_II state, and also no harm to ignore existing
 845                  * NO_OPLOCK states. JRA.
 846                  */
 847
 848                 DEBUG(10,("release_level_2_oplocks_on_change: "
 849                           "share_entry[%i]->op_type == %d\n",
 850                           i, share_entry->op_type ));
 851
 852                 if (share_entry->op_type == NO_OPLOCK) {
 853                         continue;
 854                 }
 855
 856                 /* Paranoia .... */
 857                 if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
 858                         DEBUG(0,("release_level_2_oplocks_on_change: PANIC. "
 859                                  "share mode entry %d is an exlusive "
 860                                  "oplock !\n", i ));
 861                         TALLOC_FREE(lck);
 862                         abort();
 863                 }
 864
 865                 share_mode_entry_to_message(msg, share_entry);
 866
 867                 /*
 868                  * Deal with a race condition when breaking level2
 869                  * oplocks. Don't send all the messages and release
 870                  * the lock, this allows someone else to come in and
 871                  * get a level2 lock before any of the messages are
 872                  * processed, and thus miss getting a break message.
 873                  * Ensure at least one entry (the one we're breaking)
 874                  * is processed immediately under the lock and becomes
 875                  * set as NO_OPLOCK to stop any waiter getting a level2.
 876                  * Bugid #5980.
 877                  */
 878
 879                 if (serverid_equal(&self, &share_entry->pid)) {
 880                         struct files_struct *cur_fsp =
 881                                 initial_break_processing(state->sconn,
 882                                         share_entry->id,
 883                                         share_entry->share_file_id);
 884                         wait_before_sending_break();
 885                         if (cur_fsp != NULL) {
 886                                 break_level2_to_none_async(cur_fsp);
 887                         } else {
 888                                 DEBUG(3, ("release_level_2_oplocks_on_change: "
 889                                 "Did not find fsp, ignoring\n"));
 890                         }
 891                 } else {
 892                         messaging_send_buf(state->sconn->msg_ctx,
 893                                         share_entry->pid,
 894                                         MSG_SMB_ASYNC_LEVEL2_BREAK,
 895                                         (uint8 *)msg,
 896                                         MSG_SMB_SHARE_MODE_ENTRY_SIZE);
 897                 }
 898         }
 899
 900         /* We let the message receivers handle removing the oplock state
 901            in the share mode lock db. */
 902
 903         TALLOC_FREE(lck);
 904 done:
 905         TALLOC_FREE(state);
 906         return;
 907 }
 908
 909 void smbd_contend_level2_oplocks_begin(files_struct *fsp,
 910                                   enum level2_contention_type type)
 911 {
 912         struct smbd_server_connection *sconn = fsp->conn->sconn;
 913         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 914
 915         if (koplocks && koplocks->ops->contend_level2_oplocks_begin) {
 916                 koplocks->ops->contend_level2_oplocks_begin(fsp, type);
 917                 return;
 918         }
 919
 920         contend_level2_oplocks_begin_default(fsp, type);
 921 }
 922
 923 void smbd_contend_level2_oplocks_end(files_struct *fsp,
 924                                 enum level2_contention_type type)
 925 {
 926         struct smbd_server_connection *sconn = fsp->conn->sconn;
 927         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
 928
 929         /* Only kernel oplocks implement this so far */
 930         if (koplocks && koplocks->ops->contend_level2_oplocks_end) {
 931                 koplocks->ops->contend_level2_oplocks_end(fsp, type);
 932         }
 933 }
 934
 935 /****************************************************************************
 936  Linearize a share mode entry struct to an internal oplock break message.
 937 ****************************************************************************/
 938
 939 void share_mode_entry_to_message(char *msg, const struct share_mode_entry *e)
 940 {
 941         SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32)e->pid.pid);
 942         SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
 943         SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
 944         SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
 945         SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
 946         SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
 947         SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
 948         SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
 949         push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 950         SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
 951         SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
 952         SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
 953         SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
 954         SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
 955 }
 956
 957 /****************************************************************************
 958  De-linearize an internal oplock break message to a share mode entry struct.
 959 ****************************************************************************/
 960
 961 void message_to_share_mode_entry(struct share_mode_entry *e, char *msg)
 962 {
 963         e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
 964         e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
 965         e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
 966         e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
 967         e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
 968         e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
 969         e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
 970         e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
 971         pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, &e->id);
 972         e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
 973         e->uid = (uint32)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
 974         e->flags = (uint16)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
 975         e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
 976         e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
 977 }
 978
 979 /****************************************************************************
 980  Setup oplocks for this process.
 981 ****************************************************************************/
 982
 983 bool init_oplocks(struct smbd_server_connection *sconn)
 984 {
 985         DEBUG(3,("init_oplocks: initializing messages.\n"));
 986
 987         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
 988                            process_oplock_break_message);
 989         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_ASYNC_LEVEL2_BREAK,
 990                            process_oplock_async_level2_break_message);
 991         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_RESPONSE,
 992                            process_oplock_break_response);
 993         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
 994                            process_kernel_oplock_break);
 995         messaging_register(sconn->msg_ctx, sconn, MSG_SMB_OPEN_RETRY,
 996                            process_open_retry_message);
 997
 998         return true;
 999 }
1000
1001 void init_kernel_oplocks(struct smbd_server_connection *sconn)
1002 {
1003         struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
1004
1005         /* only initialize once */
1006         if (koplocks == NULL) {
1007 #if HAVE_KERNEL_OPLOCKS_IRIX
1008                 koplocks = irix_init_kernel_oplocks(sconn);
1009 #elif HAVE_KERNEL_OPLOCKS_LINUX
1010                 koplocks = linux_init_kernel_oplocks(sconn);
1011 #endif
1012                 sconn->oplocks.kernel_ops = koplocks;
1013         }
1014 }