vcs.maemo.org Git - samba/blob - source/locking/locking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Locking functions
   4    Copyright (C) Andrew Tridgell 1992-2000
   5    Copyright (C) Jeremy Allison 1992-2000
   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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22    Revision History:
  23
  24    12 aug 96: Erik.Devriendt@te6.siemens.be
  25    added support for shared memory implementation of share mode locking
  26
  27    May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
  28    locking to deal with multiple share modes per open file.
  29
  30    September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
  31    support.
  32
  33    rewrtten completely to use new tdb code. Tridge, Dec '99
  34
  35    Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
  36 */
  37
  38 #include "includes.h"
  39 uint16 global_smbpid;
  40
  41 #undef DBGC_CLASS
  42 #define DBGC_CLASS DBGC_LOCKING
  43
  44 /* the locking database handle */
  45 static TDB_CONTEXT *tdb;
  46
  47 struct locking_data {
  48         union {
  49                 struct {
  50                         int num_share_mode_entries;
  51                         BOOL delete_on_close;
  52                 } s;
  53                 struct share_mode_entry dummy; /* Needed for alignment. */
  54         } u;
  55         /* the following two entries are implicit
  56            struct share_mode_entry modes[num_share_mode_entries];
  57            char file_name[];
  58         */
  59 };
  60
  61 /****************************************************************************
  62  Debugging aid :-).
  63 ****************************************************************************/
  64
  65 static const char *lock_type_name(enum brl_type lock_type)
  66 {
  67         return (lock_type == READ_LOCK) ? "READ" : "WRITE";
  68 }
  69
  70 /****************************************************************************
  71  Utility function called to see if a file region is locked.
  72 ****************************************************************************/
  73
  74 BOOL is_locked(files_struct *fsp,connection_struct *conn,
  75                SMB_BIG_UINT count,SMB_BIG_UINT offset,
  76                enum brl_type lock_type)
  77 {
  78         int snum = SNUM(conn);
  79         int strict_locking = lp_strict_locking(snum);
  80         BOOL ret;
  81
  82         if (count == 0)
  83                 return(False);
  84
  85         if (!lp_locking(snum) || !strict_locking)
  86                 return(False);
  87
  88         if (strict_locking == Auto) {
  89                 if  (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && (lock_type == READ_LOCK || lock_type == WRITE_LOCK)) {
  90                         DEBUG(10,("is_locked: optimisation - exclusive oplock on file %s\n", fsp->fsp_name ));
  91                         ret = 0;
  92                 } else if ((fsp->oplock_type == LEVEL_II_OPLOCK) &&
  93                            (lock_type == READ_LOCK)) {
  94                         DEBUG(10,("is_locked: optimisation - level II oplock on file %s\n", fsp->fsp_name ));
  95                         ret = 0;
  96                 } else {
  97                         ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
  98                                      global_smbpid, procid_self(), conn->cnum,
  99                                      offset, count, lock_type);
 100                 }
 101         } else {
 102                 ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum,
 103                                 global_smbpid, procid_self(), conn->cnum,
 104                                 offset, count, lock_type);
 105         }
 106
 107         DEBUG(10,("is_locked: brl start=%.0f len=%.0f %s for file %s\n",
 108                         (double)offset, (double)count, ret ? "locked" : "unlocked",
 109                         fsp->fsp_name ));
 110
 111         /*
 112          * There is no lock held by an SMB daemon, check to
 113          * see if there is a POSIX lock from a UNIX or NFS process.
 114          */
 115
 116         if(!ret && lp_posix_locking(snum)) {
 117                 ret = is_posix_locked(fsp, offset, count, lock_type);
 118
 119                 DEBUG(10,("is_locked: posix start=%.0f len=%.0f %s for file %s\n",
 120                                 (double)offset, (double)count, ret ? "locked" : "unlocked",
 121                                 fsp->fsp_name ));
 122         }
 123
 124         return ret;
 125 }
 126
 127 /****************************************************************************
 128  Utility function called by locking requests.
 129 ****************************************************************************/
 130
 131 static NTSTATUS do_lock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 132                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type, BOOL *my_lock_ctx)
 133 {
 134         NTSTATUS status = NT_STATUS_LOCK_NOT_GRANTED;
 135
 136         if (!lp_locking(SNUM(conn)))
 137                 return NT_STATUS_OK;
 138
 139         /* NOTE! 0 byte long ranges ARE allowed and should be stored  */
 140
 141         DEBUG(10,("do_lock: lock type %s start=%.0f len=%.0f requested for file %s\n",
 142                   lock_type_name(lock_type), (double)offset, (double)count, fsp->fsp_name ));
 143
 144         if (OPEN_FSP(fsp) && fsp->can_lock && (fsp->conn == conn)) {
 145                 status = brl_lock(fsp->dev, fsp->inode, fsp->fnum,
 146                                   lock_pid, procid_self(), conn->cnum,
 147                                   offset, count,
 148                                   lock_type, my_lock_ctx);
 149
 150                 if (NT_STATUS_IS_OK(status) && lp_posix_locking(SNUM(conn))) {
 151
 152                         /*
 153                          * Try and get a POSIX lock on this range.
 154                          * Note that this is ok if it is a read lock
 155                          * overlapping on a different fd. JRA.
 156                          */
 157
 158                         if (!set_posix_lock(fsp, offset, count, lock_type)) {
 159                                 if (errno == EACCES || errno == EAGAIN)
 160                                         status = NT_STATUS_FILE_LOCK_CONFLICT;
 161                                 else
 162                                         status = map_nt_error_from_unix(errno);
 163
 164                                 /*
 165                                  * We failed to map - we must now remove the brl
 166                                  * lock entry.
 167                                  */
 168                                 (void)brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 169                                                                 lock_pid, procid_self(), conn->cnum,
 170                                                                 offset, count, False,
 171                                                                 NULL, NULL);
 172                         }
 173                 }
 174         }
 175
 176         return status;
 177 }
 178
 179 /****************************************************************************
 180  Utility function called by locking requests. This is *DISGUSTING*. It also
 181  appears to be "What Windows Does" (tm). Andrew, ever wonder why Windows 2000
 182  is so slow on the locking tests...... ? This is the reason. Much though I hate
 183  it, we need this. JRA.
 184 ****************************************************************************/
 185
 186 NTSTATUS do_lock_spin(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 187                  SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type, BOOL *my_lock_ctx)
 188 {
 189         int j, maxj = lp_lock_spin_count();
 190         int sleeptime = lp_lock_sleep_time();
 191         NTSTATUS status, ret;
 192
 193         if (maxj <= 0)
 194                 maxj = 1;
 195
 196         ret = NT_STATUS_OK; /* to keep dumb compilers happy */
 197
 198         for (j = 0; j < maxj; j++) {
 199                 status = do_lock(fsp, conn, lock_pid, count, offset, lock_type, my_lock_ctx);
 200                 if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED) &&
 201                     !NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 202                         return status;
 203                 }
 204                 /* if we do fail then return the first error code we got */
 205                 if (j == 0) {
 206                         ret = status;
 207                         /* Don't spin if we blocked ourselves. */
 208                         if (*my_lock_ctx)
 209                                 return ret;
 210                 }
 211                 if (sleeptime)
 212                         sys_usleep(sleeptime);
 213         }
 214         return ret;
 215 }
 216
 217 /* Struct passed to brl_unlock. */
 218 struct posix_unlock_data_struct {
 219         files_struct *fsp;
 220         SMB_BIG_UINT offset;
 221         SMB_BIG_UINT count;
 222 };
 223
 224 /****************************************************************************
 225  Function passed to brl_unlock to allow POSIX unlock to be done first.
 226 ****************************************************************************/
 227
 228 static void posix_unlock(void *pre_data)
 229 {
 230         struct posix_unlock_data_struct *pdata = (struct posix_unlock_data_struct *)pre_data;
 231
 232         if (lp_posix_locking(SNUM(pdata->fsp->conn)))
 233                 release_posix_lock(pdata->fsp, pdata->offset, pdata->count);
 234 }
 235
 236 /****************************************************************************
 237  Utility function called by unlocking requests.
 238 ****************************************************************************/
 239
 240 NTSTATUS do_unlock(files_struct *fsp,connection_struct *conn, uint16 lock_pid,
 241                    SMB_BIG_UINT count,SMB_BIG_UINT offset)
 242 {
 243         BOOL ok = False;
 244         struct posix_unlock_data_struct posix_data;
 245
 246         if (!lp_locking(SNUM(conn)))
 247                 return NT_STATUS_OK;
 248
 249         if (!OPEN_FSP(fsp) || !fsp->can_lock || (fsp->conn != conn)) {
 250                 return NT_STATUS_INVALID_HANDLE;
 251         }
 252
 253         DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for file %s\n",
 254                   (double)offset, (double)count, fsp->fsp_name ));
 255
 256         /*
 257          * Remove the existing lock record from the tdb lockdb
 258          * before looking at POSIX locks. If this record doesn't
 259          * match then don't bother looking to remove POSIX locks.
 260          */
 261
 262         posix_data.fsp = fsp;
 263         posix_data.offset = offset;
 264         posix_data.count = count;
 265
 266         ok = brl_unlock(fsp->dev, fsp->inode, fsp->fnum,
 267                         lock_pid, procid_self(), conn->cnum, offset, count,
 268                         False, posix_unlock, (void *)&posix_data);
 269
 270         if (!ok) {
 271                 DEBUG(10,("do_unlock: returning ERRlock.\n" ));
 272                 return NT_STATUS_RANGE_NOT_LOCKED;
 273         }
 274         return NT_STATUS_OK;
 275 }
 276
 277 /****************************************************************************
 278  Remove any locks on this fd. Called from file_close().
 279 ****************************************************************************/
 280
 281 void locking_close_file(files_struct *fsp)
 282 {
 283         struct process_id pid = procid_self();
 284
 285         if (!lp_locking(SNUM(fsp->conn)))
 286                 return;
 287
 288         /*
 289          * Just release all the brl locks, no need to release individually.
 290          */
 291
 292         brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum);
 293
 294         if(lp_posix_locking(SNUM(fsp->conn))) {
 295
 296                 /*
 297                  * Release all the POSIX locks.
 298                  */
 299                 posix_locking_close_file(fsp);
 300
 301         }
 302 }
 303
 304 /****************************************************************************
 305  Initialise the locking functions.
 306 ****************************************************************************/
 307
 308 static int open_read_only;
 309
 310 BOOL locking_init(int read_only)
 311 {
 312         brl_init(read_only);
 313
 314         if (tdb)
 315                 return True;
 316
 317         tdb = tdb_open_log(lock_path("locking.tdb"),
 318                         SMB_OPEN_DATABASE_TDB_HASH_SIZE, TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
 319                         read_only?O_RDONLY:O_RDWR|O_CREAT,
 320                         0644);
 321
 322         if (!tdb) {
 323                 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
 324                 return False;
 325         }
 326
 327         if (!posix_locking_init(read_only))
 328                 return False;
 329
 330         open_read_only = read_only;
 331
 332         return True;
 333 }
 334
 335 /*******************************************************************
 336  Deinitialize the share_mode management.
 337 ******************************************************************/
 338
 339 BOOL locking_end(void)
 340 {
 341         BOOL ret = True;
 342
 343         brl_shutdown(open_read_only);
 344         if (tdb) {
 345                 if (tdb_close(tdb) != 0)
 346                         ret = False;
 347         }
 348
 349         return ret;
 350 }
 351
 352 /*******************************************************************
 353  Form a static locking key for a dev/inode pair.
 354 ******************************************************************/
 355
 356 /* key and data records in the tdb locking database */
 357 struct locking_key {
 358         SMB_DEV_T dev;
 359         SMB_INO_T ino;
 360 };
 361
 362 /*******************************************************************
 363  Form a static locking key for a dev/inode pair.
 364 ******************************************************************/
 365
 366 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
 367 {
 368         static struct locking_key key;
 369         TDB_DATA kbuf;
 370
 371         memset(&key, '\0', sizeof(key));
 372         key.dev = dev;
 373         key.ino = inode;
 374         kbuf.dptr = (char *)&key;
 375         kbuf.dsize = sizeof(key);
 376         return kbuf;
 377 }
 378
 379 /*******************************************************************
 380  Print out a share mode.
 381 ********************************************************************/
 382
 383 char *share_mode_str(int num, struct share_mode_entry *e)
 384 {
 385         static pstring share_str;
 386
 387         slprintf(share_str, sizeof(share_str)-1, "share_mode_entry[%d]: %s "
 388                  "pid = %s, share_access = 0x%x, private_options = 0x%x, "
 389                  "access_mask = 0x%x, mid = 0x%x, type= 0x%x, file_id = %lu, "
 390                  "dev = 0x%x, inode = %.0f",
 391                  num,
 392                  e->op_type == UNUSED_SHARE_MODE_ENTRY ? "UNUSED" : "",
 393                  procid_str_static(&e->pid),
 394                  e->share_access, e->private_options,
 395                  e->access_mask, e->op_mid, e->op_type, e->share_file_id,
 396                  (unsigned int)e->dev, (double)e->inode );
 397
 398         return share_str;
 399 }
 400
 401 /*******************************************************************
 402  Print out a share mode table.
 403 ********************************************************************/
 404
 405 static void print_share_mode_table(struct locking_data *data)
 406 {
 407         int num_share_modes = data->u.s.num_share_mode_entries;
 408         struct share_mode_entry *shares =
 409                 (struct share_mode_entry *)(data + 1);
 410         int i;
 411
 412         for (i = 0; i < num_share_modes; i++) {
 413                 struct share_mode_entry entry;
 414
 415                 memcpy(&entry, &shares[i], sizeof(struct share_mode_entry));
 416                 DEBUG(10,("print_share_mode_table: %s\n",
 417                           share_mode_str(i, &entry)));
 418         }
 419 }
 420
 421 /*******************************************************************
 422  Get all share mode entries for a dev/inode pair.
 423 ********************************************************************/
 424
 425 static BOOL parse_share_modes(TDB_DATA dbuf, struct share_mode_lock *lck)
 426 {
 427         struct locking_data *data;
 428         int i;
 429
 430         if (dbuf.dsize < sizeof(struct locking_data)) {
 431                 DEBUG(0, ("parse_share_modes: buffer too short\n"));
 432                 return False;
 433         }
 434
 435         data = (struct locking_data *)dbuf.dptr;
 436
 437         lck->delete_on_close = data->u.s.delete_on_close;
 438         lck->num_share_modes = data->u.s.num_share_mode_entries;
 439
 440         DEBUG(10, ("parse_share_modes: delete_on_close: %d, "
 441                    "num_share_modes: %d\n", lck->delete_on_close,
 442                    lck->num_share_modes));
 443
 444         if ((lck->num_share_modes < 0) || (lck->num_share_modes > 1000000)) {
 445                 DEBUG(0, ("invalid number of share modes: %d\n",
 446                           lck->num_share_modes));
 447                 return False;
 448         }
 449
 450         lck->share_modes = NULL;
 451
 452         if (lck->num_share_modes != 0) {
 453
 454                 if (dbuf.dsize < (sizeof(struct locking_data) +
 455                                   (lck->num_share_modes *
 456                                    sizeof(struct share_mode_entry)))) {
 457                         DEBUG(0, ("parse_share_modes: buffer too short\n"));
 458                         return False;
 459                 }
 460
 461                 lck->share_modes = talloc_memdup(lck, dbuf.dptr+sizeof(*data),
 462                                                  lck->num_share_modes *
 463                                                  sizeof(struct share_mode_entry));
 464
 465                 if (lck->share_modes == NULL) {
 466                         DEBUG(0, ("talloc failed\n"));
 467                         return False;
 468                 }
 469         }
 470
 471         /* Save off the associated service path and filename. */
 472         lck->servicepath = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
 473                                       (lck->num_share_modes *
 474                                       sizeof(struct share_mode_entry)));
 475
 476         lck->filename = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
 477                                       (lck->num_share_modes *
 478                                       sizeof(struct share_mode_entry)) +
 479                                       strlen(lck->servicepath) + 1 );
 480
 481         /*
 482          * Ensure that each entry has a real process attached.
 483          */
 484
 485         for (i = 0; i < lck->num_share_modes; i++) {
 486                 struct share_mode_entry *entry_p = &lck->share_modes[i];
 487                 DEBUG(10,("parse_share_modes: %s\n",
 488                           share_mode_str(i, entry_p) ));
 489                 if (!process_exists(entry_p->pid)) {
 490                         DEBUG(10,("parse_share_modes: deleted %s\n",
 491                                   share_mode_str(i, entry_p) ));
 492                         entry_p->op_type = UNUSED_SHARE_MODE_ENTRY;
 493                         lck->modified = True;
 494                 }
 495         }
 496
 497         return True;
 498 }
 499
 500 static TDB_DATA unparse_share_modes(struct share_mode_lock *lck)
 501 {
 502         TDB_DATA result;
 503         int num_valid = 0;
 504         int i;
 505         struct locking_data *data;
 506         ssize_t offset;
 507         ssize_t sp_len;
 508
 509         result.dptr = NULL;
 510         result.dsize = 0;
 511
 512         for (i=0; i<lck->num_share_modes; i++) {
 513                 if (!is_unused_share_mode_entry(&lck->share_modes[i])) {
 514                         num_valid += 1;
 515                 }
 516         }
 517
 518         if (num_valid == 0) {
 519                 return result;
 520         }
 521
 522         sp_len = strlen(lck->servicepath);
 523
 524         result.dsize = sizeof(*data) +
 525                 lck->num_share_modes * sizeof(struct share_mode_entry) +
 526                 sp_len + 1 +
 527                 strlen(lck->filename) + 1;
 528         result.dptr = talloc_size(lck, result.dsize);
 529
 530         if (result.dptr == NULL) {
 531                 smb_panic("talloc failed\n");
 532         }
 533
 534         data = (struct locking_data *)result.dptr;
 535         ZERO_STRUCTP(data);
 536         data->u.s.num_share_mode_entries = lck->num_share_modes;
 537         data->u.s.delete_on_close = lck->delete_on_close;
 538         DEBUG(10, ("unparse_share_modes: del: %d, num: %d\n",
 539                    data->u.s.delete_on_close,
 540                    data->u.s.num_share_mode_entries));
 541         memcpy(result.dptr + sizeof(*data), lck->share_modes,
 542                sizeof(struct share_mode_entry)*lck->num_share_modes);
 543         offset = sizeof(*data) +
 544                 sizeof(struct share_mode_entry)*lck->num_share_modes;
 545         safe_strcpy(result.dptr + offset, lck->servicepath,
 546                     result.dsize - offset - 1);
 547         offset += sp_len + 1;
 548         safe_strcpy(result.dptr + offset, lck->filename,
 549                     result.dsize - offset - 1);
 550
 551         if (DEBUGLEVEL >= 10) {
 552                 print_share_mode_table(data);
 553         }
 554
 555         return result;
 556 }
 557
 558 static int share_mode_lock_destructor(void *p)
 559 {
 560         struct share_mode_lock *lck =
 561                 talloc_get_type_abort(p, struct share_mode_lock);
 562         TDB_DATA key = locking_key(lck->dev, lck->ino);
 563         TDB_DATA data;
 564
 565         if (!lck->modified) {
 566                 goto done;
 567         }
 568
 569         data = unparse_share_modes(lck);
 570
 571         if (data.dptr == NULL) {
 572                 if (!lck->fresh) {
 573                         /* There has been an entry before, delete it */
 574                         if (tdb_delete(tdb, key) == -1) {
 575                                 smb_panic("Could not delete share entry\n");
 576                         }
 577                 }
 578                 goto done;
 579         }
 580
 581         if (tdb_store(tdb, key, data, TDB_REPLACE) == -1) {
 582                 smb_panic("Could not store share mode entry\n");
 583         }
 584
 585  done:
 586         tdb_chainunlock(tdb, key);
 587
 588         return 0;
 589 }
 590
 591 struct share_mode_lock *get_share_mode_lock(TALLOC_CTX *mem_ctx,
 592                                             SMB_DEV_T dev, SMB_INO_T ino,
 593                                                 const char *servicepath,
 594                                             const char *fname)
 595 {
 596         struct share_mode_lock *lck;
 597         TDB_DATA key = locking_key(dev, ino);
 598         TDB_DATA data;
 599
 600         lck = TALLOC_P(mem_ctx, struct share_mode_lock);
 601         if (lck == NULL) {
 602                 DEBUG(0, ("talloc failed\n"));
 603                 return NULL;
 604         }
 605
 606         /* Ensure we set every field here as the destructor must be
 607            valid even if parse_share_modes fails. */
 608
 609         lck->servicepath = NULL;
 610         lck->filename = NULL;
 611         lck->dev = dev;
 612         lck->ino = ino;
 613         lck->num_share_modes = 0;
 614         lck->share_modes = NULL;
 615         lck->delete_on_close = False;
 616         lck->fresh = False;
 617         lck->modified = False;
 618
 619         if (tdb_chainlock(tdb, key) != 0) {
 620                 DEBUG(3, ("Could not lock share entry\n"));
 621                 talloc_free(lck);
 622                 return NULL;
 623         }
 624
 625         /* We must set the destructor immediately after the chainlock
 626            ensure the lock is cleaned up on any of the error return
 627            paths below. */
 628
 629         talloc_set_destructor(lck, share_mode_lock_destructor);
 630
 631         data = tdb_fetch(tdb, key);
 632         lck->fresh = (data.dptr == NULL);
 633
 634         if (lck->fresh) {
 635
 636                 if (fname == NULL || servicepath == NULL) {
 637                         talloc_free(lck);
 638                         return NULL;
 639                 }
 640                 lck->filename = talloc_strdup(lck, fname);
 641                 lck->servicepath = talloc_strdup(lck, servicepath);
 642                 if (lck->filename == NULL || lck->servicepath == NULL) {
 643                         DEBUG(0, ("talloc failed\n"));
 644                         talloc_free(lck);
 645                         return NULL;
 646                 }
 647         } else {
 648                 if (!parse_share_modes(data, lck)) {
 649                         DEBUG(0, ("Could not parse share modes\n"));
 650                         talloc_free(lck);
 651                         SAFE_FREE(data.dptr);
 652                         return NULL;
 653                 }
 654         }
 655
 656         SAFE_FREE(data.dptr);
 657
 658         return lck;
 659 }
 660
 661 BOOL get_delete_on_close_flag(SMB_DEV_T dev, SMB_INO_T inode,
 662                               const char *fname)
 663 {
 664         BOOL result;
 665         struct share_mode_lock *lck = get_share_mode_lock(NULL, dev, inode, NULL, NULL);
 666         if (!lck) {
 667                 return False;
 668         }
 669         result = lck->delete_on_close;
 670         talloc_free(lck);
 671         return result;
 672 }
 673
 674 BOOL is_valid_share_mode_entry(const struct share_mode_entry *e)
 675 {
 676         int num_props = 0;
 677
 678         num_props += ((e->op_type == NO_OPLOCK) ? 1 : 0);
 679         num_props += (EXCLUSIVE_OPLOCK_TYPE(e->op_type) ? 1 : 0);
 680         num_props += (LEVEL_II_OPLOCK_TYPE(e->op_type) ? 1 : 0);
 681
 682         SMB_ASSERT(num_props <= 1);
 683         return (num_props != 0);
 684 }
 685
 686 BOOL is_deferred_open_entry(const struct share_mode_entry *e)
 687 {
 688         return (e->op_type == DEFERRED_OPEN_ENTRY);
 689 }
 690
 691 BOOL is_unused_share_mode_entry(const struct share_mode_entry *e)
 692 {
 693         return (e->op_type == UNUSED_SHARE_MODE_ENTRY);
 694 }
 695
 696 /*******************************************************************
 697  Fill a share mode entry.
 698 ********************************************************************/
 699
 700 static void fill_share_mode_entry(struct share_mode_entry *e,
 701                                   files_struct *fsp,
 702                                   uint16 mid, uint16 op_type)
 703 {
 704         ZERO_STRUCTP(e);
 705         e->pid = procid_self();
 706         e->share_access = fsp->share_access;
 707         e->private_options = fsp->fh->private_options;
 708         e->access_mask = fsp->access_mask;
 709         e->op_mid = mid;
 710         e->op_type = op_type;
 711         e->time.tv_sec = fsp->open_time.tv_sec;
 712         e->time.tv_usec = fsp->open_time.tv_usec;
 713         e->share_file_id = fsp->file_id;
 714         e->dev = fsp->dev;
 715         e->inode = fsp->inode;
 716 }
 717
 718 static void fill_deferred_open_entry(struct share_mode_entry *e,
 719                                      const struct timeval request_time,
 720                                      SMB_DEV_T dev, SMB_INO_T ino, uint16 mid)
 721 {
 722         ZERO_STRUCTP(e);
 723         e->pid = procid_self();
 724         e->op_mid = mid;
 725         e->op_type = DEFERRED_OPEN_ENTRY;
 726         e->time.tv_sec = request_time.tv_sec;
 727         e->time.tv_usec = request_time.tv_usec;
 728         e->dev = dev;
 729         e->inode = ino;
 730 }
 731
 732 static void add_share_mode_entry(struct share_mode_lock *lck,
 733                                  const struct share_mode_entry *entry)
 734 {
 735         int i;
 736
 737         for (i=0; i<lck->num_share_modes; i++) {
 738                 struct share_mode_entry *e = &lck->share_modes[i];
 739                 if (is_unused_share_mode_entry(e)) {
 740                         *e = *entry;
 741                         break;
 742                 }
 743         }
 744
 745         if (i == lck->num_share_modes) {
 746                 /* No unused entry found */
 747                 ADD_TO_ARRAY(lck, struct share_mode_entry, *entry,
 748                              &lck->share_modes, &lck->num_share_modes);
 749         }
 750         lck->modified = True;
 751 }
 752
 753 void set_share_mode(struct share_mode_lock *lck, files_struct *fsp,
 754                     uint16 mid, uint16 op_type)
 755 {
 756         struct share_mode_entry entry;
 757         fill_share_mode_entry(&entry, fsp, mid, op_type);
 758         add_share_mode_entry(lck, &entry);
 759 }
 760
 761 void add_deferred_open(struct share_mode_lock *lck, uint16 mid,
 762                        struct timeval request_time,
 763                        SMB_DEV_T dev, SMB_INO_T ino)
 764 {
 765         struct share_mode_entry entry;
 766         fill_deferred_open_entry(&entry, request_time, dev, ino, mid);
 767         add_share_mode_entry(lck, &entry);
 768 }
 769
 770 /*******************************************************************
 771  Check if two share mode entries are identical, ignoring oplock
 772  and mid info and desired_access.
 773 ********************************************************************/
 774
 775 static BOOL share_modes_identical(struct share_mode_entry *e1,
 776                                   struct share_mode_entry *e2)
 777 {
 778 #if 1 /* JRA PARANOIA TEST - REMOVE LATER */
 779         if (procid_equal(&e1->pid, &e2->pid) &&
 780             e1->share_file_id == e2->share_file_id &&
 781             e1->dev == e2->dev &&
 782             e1->inode == e2->inode &&
 783             (e1->share_access) != (e2->share_access)) {
 784                 DEBUG(0,("PANIC: share_modes_identical: share_mode "
 785                          "mismatch (e1 = 0x%x, e2 = 0x%x). Logic error.\n",
 786                          (unsigned int)e1->share_access,
 787                          (unsigned int)e2->share_access ));
 788                 smb_panic("PANIC: share_modes_identical logic error.\n");
 789         }
 790 #endif
 791
 792         return (procid_equal(&e1->pid, &e2->pid) &&
 793                 (e1->share_access) == (e2->share_access) &&
 794                 e1->dev == e2->dev &&
 795                 e1->inode == e2->inode &&
 796                 e1->share_file_id == e2->share_file_id );
 797 }
 798
 799 static BOOL deferred_open_identical(struct share_mode_entry *e1,
 800                                     struct share_mode_entry *e2)
 801 {
 802         return (procid_equal(&e1->pid, &e2->pid) &&
 803                 (e1->op_mid == e2->op_mid) &&
 804                 (e1->dev == e2->dev) &&
 805                 (e1->inode == e2->inode));
 806 }
 807
 808 static struct share_mode_entry *find_share_mode_entry(struct share_mode_lock *lck,
 809                                                       struct share_mode_entry *entry)
 810 {
 811         int i;
 812
 813         for (i=0; i<lck->num_share_modes; i++) {
 814                 struct share_mode_entry *e = &lck->share_modes[i];
 815                 if (is_valid_share_mode_entry(entry) &&
 816                     is_valid_share_mode_entry(e) &&
 817                     share_modes_identical(e, entry)) {
 818                         return e;
 819                 }
 820                 if (is_deferred_open_entry(entry) &&
 821                     is_deferred_open_entry(e) &&
 822                     deferred_open_identical(e, entry)) {
 823                         return e;
 824                 }
 825         }
 826         return NULL;
 827 }
 828
 829 /*******************************************************************
 830  Del the share mode of a file for this process. Return the number of
 831  entries left.
 832 ********************************************************************/
 833
 834 BOOL del_share_mode(struct share_mode_lock *lck, files_struct *fsp)
 835 {
 836         struct share_mode_entry entry, *e;
 837
 838         fill_share_mode_entry(&entry, fsp, 0, 0);
 839
 840         e = find_share_mode_entry(lck, &entry);
 841         if (e == NULL) {
 842                 return False;
 843         }
 844
 845         e->op_type = UNUSED_SHARE_MODE_ENTRY;
 846         lck->modified = True;
 847         return True;
 848 }
 849
 850 void del_deferred_open_entry(struct share_mode_lock *lck, uint16 mid)
 851 {
 852         struct share_mode_entry entry, *e;
 853
 854         fill_deferred_open_entry(&entry, timeval_zero(),
 855                                  lck->dev, lck->ino, mid);
 856
 857         e = find_share_mode_entry(lck, &entry);
 858         if (e == NULL) {
 859                 return;
 860         }
 861
 862         e->op_type = UNUSED_SHARE_MODE_ENTRY;
 863         lck->modified = True;
 864 }
 865
 866 /*******************************************************************
 867  Remove an oplock mid and mode entry from a share mode.
 868 ********************************************************************/
 869
 870 BOOL remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
 871 {
 872         struct share_mode_entry entry, *e;
 873
 874         fill_share_mode_entry(&entry, fsp, 0, 0);
 875
 876         e = find_share_mode_entry(lck, &entry);
 877         if (e == NULL) {
 878                 return False;
 879         }
 880
 881         e->op_mid = 0;
 882         e->op_type = NO_OPLOCK;
 883         lck->modified = True;
 884         return True;
 885 }
 886
 887 /*******************************************************************
 888  Downgrade a oplock type from exclusive to level II.
 889 ********************************************************************/
 890
 891 BOOL downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
 892 {
 893         struct share_mode_entry entry, *e;
 894
 895         fill_share_mode_entry(&entry, fsp, 0, 0);
 896
 897         e = find_share_mode_entry(lck, &entry);
 898         if (e == NULL) {
 899                 return False;
 900         }
 901
 902         e->op_type = LEVEL_II_OPLOCK;
 903         lck->modified = True;
 904         return True;
 905 }
 906
 907 /****************************************************************************
 908  Deal with the internal needs of setting the delete on close flag. Note that
 909  as the tdb locking is recursive, it is safe to call this from within
 910  open_file_shared. JRA.
 911 ****************************************************************************/
 912
 913 NTSTATUS can_set_delete_on_close(files_struct *fsp, BOOL delete_on_close,
 914                                  uint32 dosmode)
 915 {
 916         if (!delete_on_close) {
 917                 return NT_STATUS_OK;
 918         }
 919
 920         /*
 921          * Only allow delete on close for writable files.
 922          */
 923
 924         if ((dosmode & aRONLY) &&
 925             !lp_delete_readonly(SNUM(fsp->conn))) {
 926                 DEBUG(10,("can_set_delete_on_close: file %s delete on close "
 927                           "flag set but file attribute is readonly.\n",
 928                           fsp->fsp_name ));
 929                 return NT_STATUS_CANNOT_DELETE;
 930         }
 931
 932         /*
 933          * Only allow delete on close for writable shares.
 934          */
 935
 936         if (!CAN_WRITE(fsp->conn)) {
 937                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
 938                           "close flag set but write access denied on share.\n",
 939                           fsp->fsp_name ));
 940                 return NT_STATUS_ACCESS_DENIED;
 941         }
 942
 943         /*
 944          * Only allow delete on close for files/directories opened with delete
 945          * intent.
 946          */
 947
 948         if (!(fsp->access_mask & DELETE_ACCESS)) {
 949                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
 950                           "close flag set but delete access denied.\n",
 951                           fsp->fsp_name ));
 952                 return NT_STATUS_ACCESS_DENIED;
 953         }
 954
 955         return NT_STATUS_OK;
 956 }
 957
 958 /****************************************************************************
 959  Sets the delete on close flag over all share modes on this file.
 960  Modify the share mode entry for all files open
 961  on this device and inode to tell other smbds we have
 962  changed the delete on close flag. This will be noticed
 963  in the close code, the last closer will delete the file
 964  if flag is set.
 965 ****************************************************************************/
 966
 967 BOOL set_delete_on_close(files_struct *fsp, BOOL delete_on_close)
 968 {
 969         struct share_mode_lock *lck;
 970
 971         DEBUG(10,("set_delete_on_close: %s delete on close flag for "
 972                   "fnum = %d, file %s\n",
 973                   delete_on_close ? "Adding" : "Removing", fsp->fnum,
 974                   fsp->fsp_name ));
 975
 976         if (fsp->is_stat) {
 977                 return True;
 978         }
 979
 980         lck = get_share_mode_lock(NULL, fsp->dev, fsp->inode, NULL, NULL);
 981         if (lck == NULL) {
 982                 return False;
 983         }
 984         if (lck->delete_on_close != delete_on_close) {
 985                 lck->delete_on_close = delete_on_close;
 986                 lck->modified = True;
 987         }
 988
 989         talloc_free(lck);
 990         return True;
 991 }
 992
 993 static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf,
 994                        void *state)
 995 {
 996         struct locking_data *data;
 997         struct share_mode_entry *shares;
 998         const char *sharepath;
 999         const char *fname;
1000         int i;
1001         void (*traverse_callback)(struct share_mode_entry *, const char *, const char *) = state;
1002
1003         /* Ensure this is a locking_key record. */
1004         if (kbuf.dsize != sizeof(struct locking_key))
1005                 return 0;
1006
1007         data = (struct locking_data *)dbuf.dptr;
1008         shares = (struct share_mode_entry *)(dbuf.dptr + sizeof(*data));
1009         sharepath = dbuf.dptr + sizeof(*data) +
1010                 data->u.s.num_share_mode_entries*sizeof(*shares);
1011         fname = dbuf.dptr + sizeof(*data) +
1012                 data->u.s.num_share_mode_entries*sizeof(*shares) +
1013                 strlen(sharepath) + 1;
1014
1015         for (i=0;i<data->u.s.num_share_mode_entries;i++) {
1016                 traverse_callback(&shares[i], sharepath, fname);
1017         }
1018         return 0;
1019 }
1020
1021 /*******************************************************************
1022  Call the specified function on each entry under management by the
1023  share mode system.
1024 ********************************************************************/
1025
1026 int share_mode_forall(void (*fn)(const struct share_mode_entry *, const char *, const char *))
1027 {
1028         if (tdb == NULL)
1029                 return 0;
1030         return tdb_traverse(tdb, traverse_fn, fn);
1031 }