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 1992-2006
   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    Added Unix Extensions POSIX locking support. Jeremy Allison Mar 2006.
  37 */
  38
  39 #include "includes.h"
  40 uint16 global_smbpid;
  41
  42 #undef DBGC_CLASS
  43 #define DBGC_CLASS DBGC_LOCKING
  44
  45 /* the locking database handle */
  46 static TDB_CONTEXT *tdb;
  47
  48 /****************************************************************************
  49  Debugging aids :-).
  50 ****************************************************************************/
  51
  52 const char *lock_type_name(enum brl_type lock_type)
  53 {
  54         switch (lock_type) {
  55                 case READ_LOCK:
  56                         return "READ";
  57                 case WRITE_LOCK:
  58                         return "WRITE";
  59                 case PENDING_LOCK:
  60                         return "PENDING";
  61                 default:
  62                         return "other";
  63         }
  64 }
  65
  66 const char *lock_flav_name(enum brl_flavour lock_flav)
  67 {
  68         return (lock_flav == WINDOWS_LOCK) ? "WINDOWS_LOCK" : "POSIX_LOCK";
  69 }
  70
  71 /****************************************************************************
  72  Utility function called to see if a file region is locked.
  73  Called in the read/write codepath.
  74 ****************************************************************************/
  75
  76 BOOL is_locked(files_struct *fsp,
  77                 SMB_BIG_UINT count,
  78                 SMB_BIG_UINT offset,
  79                 enum brl_type lock_type)
  80 {
  81         int snum = SNUM(fsp->conn);
  82         int strict_locking = lp_strict_locking(snum);
  83         enum brl_flavour lock_flav = lp_posix_cifsu_locktype();
  84         BOOL ret = True;
  85
  86         if (count == 0) {
  87                 return False;
  88         }
  89
  90         if (!lp_locking(snum) || !strict_locking) {
  91                 return False;
  92         }
  93
  94         if (strict_locking == Auto) {
  95                 if  (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && (lock_type == READ_LOCK || lock_type == WRITE_LOCK)) {
  96                         DEBUG(10,("is_locked: optimisation - exclusive oplock on file %s\n", fsp->fsp_name ));
  97                         ret = False;
  98                 } else if ((fsp->oplock_type == LEVEL_II_OPLOCK) &&
  99                            (lock_type == READ_LOCK)) {
 100                         DEBUG(10,("is_locked: optimisation - level II oplock on file %s\n", fsp->fsp_name ));
 101                         ret = False;
 102                 } else {
 103                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 104                         if (!br_lck) {
 105                                 return False;
 106                         }
 107                         ret = !brl_locktest(br_lck,
 108                                         global_smbpid,
 109                                         procid_self(),
 110                                         offset,
 111                                         count,
 112                                         lock_type,
 113                                         lock_flav);
 114                         TALLOC_FREE(br_lck);
 115                 }
 116         } else {
 117                 struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 118                 if (!br_lck) {
 119                         return False;
 120                 }
 121                 ret = !brl_locktest(br_lck,
 122                                 global_smbpid,
 123                                 procid_self(),
 124                                 offset,
 125                                 count,
 126                                 lock_type,
 127                                 lock_flav);
 128                 TALLOC_FREE(br_lck);
 129         }
 130
 131         DEBUG(10,("is_locked: flavour = %s brl start=%.0f len=%.0f %s for fnum %d file %s\n",
 132                         lock_flav_name(lock_flav),
 133                         (double)offset, (double)count, ret ? "locked" : "unlocked",
 134                         fsp->fnum, fsp->fsp_name ));
 135
 136         return ret;
 137 }
 138
 139 /****************************************************************************
 140  Find out if a lock could be granted - return who is blocking us if we can't.
 141 ****************************************************************************/
 142
 143 NTSTATUS query_lock(files_struct *fsp,
 144                         uint16 *psmbpid,
 145                         SMB_BIG_UINT *pcount,
 146                         SMB_BIG_UINT *poffset,
 147                         enum brl_type *plock_type,
 148                         enum brl_flavour lock_flav)
 149 {
 150         struct byte_range_lock *br_lck = NULL;
 151         NTSTATUS status = NT_STATUS_LOCK_NOT_GRANTED;
 152
 153         if (!OPEN_FSP(fsp) || !fsp->can_lock) {
 154                 return NT_STATUS_INVALID_HANDLE;
 155         }
 156
 157         if (!lp_locking(SNUM(fsp->conn))) {
 158                 return NT_STATUS_OK;
 159         }
 160
 161         br_lck = brl_get_locks(NULL, fsp);
 162         if (!br_lck) {
 163                 return NT_STATUS_NO_MEMORY;
 164         }
 165
 166         status = brl_lockquery(br_lck,
 167                         psmbpid,
 168                         procid_self(),
 169                         poffset,
 170                         pcount,
 171                         plock_type,
 172                         lock_flav);
 173
 174         TALLOC_FREE(br_lck);
 175         return status;
 176 }
 177
 178 /****************************************************************************
 179  Utility function called by locking requests.
 180 ****************************************************************************/
 181
 182 NTSTATUS do_lock(files_struct *fsp,
 183                         uint16 lock_pid,
 184                         SMB_BIG_UINT count,
 185                         SMB_BIG_UINT offset,
 186                         enum brl_type lock_type,
 187                         enum brl_flavour lock_flav,
 188                         BOOL *my_lock_ctx)
 189 {
 190         struct byte_range_lock *br_lck = NULL;
 191         NTSTATUS status = NT_STATUS_LOCK_NOT_GRANTED;
 192
 193         if (!OPEN_FSP(fsp) || !fsp->can_lock) {
 194                 return NT_STATUS_INVALID_HANDLE;
 195         }
 196
 197         if (!lp_locking(SNUM(fsp->conn))) {
 198                 return NT_STATUS_OK;
 199         }
 200
 201         /* NOTE! 0 byte long ranges ARE allowed and should be stored  */
 202
 203         DEBUG(10,("do_lock: lock flavour %s lock type %s start=%.0f len=%.0f requested for fnum %d file %s\n",
 204                 lock_flav_name(lock_flav), lock_type_name(lock_type),
 205                 (double)offset, (double)count, fsp->fnum, fsp->fsp_name ));
 206
 207         br_lck = brl_get_locks(NULL, fsp);
 208         if (!br_lck) {
 209                 return NT_STATUS_NO_MEMORY;
 210         }
 211
 212         status = brl_lock(br_lck,
 213                         lock_pid,
 214                         procid_self(),
 215                         offset,
 216                         count,
 217                         lock_type,
 218                         lock_flav,
 219                         my_lock_ctx);
 220
 221         TALLOC_FREE(br_lck);
 222         return status;
 223 }
 224
 225 /****************************************************************************
 226  Utility function called by locking requests. This is *DISGUSTING*. It also
 227  appears to be "What Windows Does" (tm). Andrew, ever wonder why Windows 2000
 228  is so slow on the locking tests...... ? This is the reason. Much though I hate
 229  it, we need this. JRA.
 230 ****************************************************************************/
 231
 232 NTSTATUS do_lock_spin(files_struct *fsp,
 233                         uint16 lock_pid,
 234                         SMB_BIG_UINT count,
 235                         SMB_BIG_UINT offset,
 236                         enum brl_type lock_type,
 237                         enum brl_flavour lock_flav,
 238                         BOOL *my_lock_ctx)
 239 {
 240         int j, maxj = lp_lock_spin_count();
 241         int sleeptime = lp_lock_sleep_time();
 242         NTSTATUS status, ret;
 243
 244         if (maxj <= 0) {
 245                 maxj = 1;
 246         }
 247
 248         ret = NT_STATUS_OK; /* to keep dumb compilers happy */
 249
 250         for (j = 0; j < maxj; j++) {
 251                 status = do_lock(fsp,
 252                                 lock_pid,
 253                                 count,
 254                                 offset,
 255                                 lock_type,
 256                                 lock_flav,
 257                                 my_lock_ctx);
 258
 259                 if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED) &&
 260                     !NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 261                         return status;
 262                 }
 263                 /* if we do fail then return the first error code we got */
 264                 if (j == 0) {
 265                         ret = status;
 266                         /* Don't spin if we blocked ourselves. */
 267                         if (*my_lock_ctx) {
 268                                 return ret;
 269                         }
 270
 271                         /* Only spin for Windows locks. */
 272                         if (lock_flav == POSIX_LOCK) {
 273                                 return ret;
 274                         }
 275                 }
 276
 277                 if (sleeptime) {
 278                         sys_usleep(sleeptime);
 279                 }
 280         }
 281         return ret;
 282 }
 283
 284 /****************************************************************************
 285  Utility function called by unlocking requests.
 286 ****************************************************************************/
 287
 288 NTSTATUS do_unlock(files_struct *fsp,
 289                         uint16 lock_pid,
 290                         SMB_BIG_UINT count,
 291                         SMB_BIG_UINT offset,
 292                         enum brl_flavour lock_flav)
 293 {
 294         BOOL ok = False;
 295         struct byte_range_lock *br_lck = NULL;
 296
 297         if (!lp_locking(SNUM(fsp->conn))) {
 298                 return NT_STATUS_OK;
 299         }
 300
 301         if (!OPEN_FSP(fsp) || !fsp->can_lock) {
 302                 return NT_STATUS_INVALID_HANDLE;
 303         }
 304
 305         DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for fnum %d file %s\n",
 306                   (double)offset, (double)count, fsp->fnum, fsp->fsp_name ));
 307
 308         br_lck = brl_get_locks(NULL, fsp);
 309         if (!br_lck) {
 310                 return NT_STATUS_NO_MEMORY;
 311         }
 312
 313         ok = brl_unlock(br_lck,
 314                         lock_pid,
 315                         procid_self(),
 316                         offset,
 317                         count,
 318                         lock_flav);
 319
 320         TALLOC_FREE(br_lck);
 321
 322         if (!ok) {
 323                 DEBUG(10,("do_unlock: returning ERRlock.\n" ));
 324                 return NT_STATUS_RANGE_NOT_LOCKED;
 325         }
 326
 327         return NT_STATUS_OK;
 328 }
 329
 330 /****************************************************************************
 331  Remove any locks on this fd. Called from file_close().
 332 ****************************************************************************/
 333
 334 void locking_close_file(files_struct *fsp)
 335 {
 336         struct byte_range_lock *br_lck;
 337         struct process_id pid = procid_self();
 338
 339         if (!lp_locking(SNUM(fsp->conn)))
 340                 return;
 341
 342         /*
 343          * Just release all the brl locks, no need to release individually.
 344          */
 345
 346         br_lck = brl_get_locks(NULL,fsp);
 347         if (br_lck) {
 348                 brl_close_fnum(br_lck, pid);
 349                 TALLOC_FREE(br_lck);
 350         }
 351
 352         if(lp_posix_locking(SNUM(fsp->conn))) {
 353                 /* Release all the POSIX locks.*/
 354                 posix_locking_close_file(fsp);
 355
 356         }
 357 }
 358
 359 /****************************************************************************
 360  Initialise the locking functions.
 361 ****************************************************************************/
 362
 363 static int open_read_only;
 364
 365 BOOL locking_init(int read_only)
 366 {
 367         brl_init(read_only);
 368
 369         if (tdb)
 370                 return True;
 371
 372         tdb = tdb_open_log(lock_path("locking.tdb"),
 373                         lp_open_files_db_hash_size(),
 374                         TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST),
 375                         read_only?O_RDONLY:O_RDWR|O_CREAT,
 376                         0644);
 377
 378         if (!tdb) {
 379                 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
 380                 return False;
 381         }
 382
 383         if (!posix_locking_init(read_only))
 384                 return False;
 385
 386         open_read_only = read_only;
 387
 388         return True;
 389 }
 390
 391 /*******************************************************************
 392  Deinitialize the share_mode management.
 393 ******************************************************************/
 394
 395 BOOL locking_end(void)
 396 {
 397         BOOL ret = True;
 398
 399         brl_shutdown(open_read_only);
 400         if (tdb) {
 401                 if (tdb_close(tdb) != 0)
 402                         ret = False;
 403         }
 404
 405         return ret;
 406 }
 407
 408 /*******************************************************************
 409  Form a static locking key for a dev/inode pair.
 410 ******************************************************************/
 411
 412 /* key and data records in the tdb locking database */
 413 struct locking_key {
 414         SMB_DEV_T dev;
 415         SMB_INO_T ino;
 416 };
 417
 418 /*******************************************************************
 419  Form a static locking key for a dev/inode pair.
 420 ******************************************************************/
 421
 422 static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode)
 423 {
 424         static struct locking_key key;
 425         TDB_DATA kbuf;
 426
 427         memset(&key, '\0', sizeof(key));
 428         key.dev = dev;
 429         key.ino = inode;
 430         kbuf.dptr = (char *)&key;
 431         kbuf.dsize = sizeof(key);
 432         return kbuf;
 433 }
 434
 435 /*******************************************************************
 436  Print out a share mode.
 437 ********************************************************************/
 438
 439 char *share_mode_str(int num, struct share_mode_entry *e)
 440 {
 441         static pstring share_str;
 442
 443         slprintf(share_str, sizeof(share_str)-1, "share_mode_entry[%d]: %s "
 444                  "pid = %s, share_access = 0x%x, private_options = 0x%x, "
 445                  "access_mask = 0x%x, mid = 0x%x, type= 0x%x, file_id = %lu, "
 446                  "dev = 0x%x, inode = %.0f",
 447                  num,
 448                  e->op_type == UNUSED_SHARE_MODE_ENTRY ? "UNUSED" : "",
 449                  procid_str_static(&e->pid),
 450                  e->share_access, e->private_options,
 451                  e->access_mask, e->op_mid, e->op_type, e->share_file_id,
 452                  (unsigned int)e->dev, (double)e->inode );
 453
 454         return share_str;
 455 }
 456
 457 /*******************************************************************
 458  Print out a share mode table.
 459 ********************************************************************/
 460
 461 static void print_share_mode_table(struct locking_data *data)
 462 {
 463         int num_share_modes = data->u.s.num_share_mode_entries;
 464         struct share_mode_entry *shares =
 465                 (struct share_mode_entry *)(data + 1);
 466         int i;
 467
 468         for (i = 0; i < num_share_modes; i++) {
 469                 struct share_mode_entry entry;
 470
 471                 memcpy(&entry, &shares[i], sizeof(struct share_mode_entry));
 472                 DEBUG(10,("print_share_mode_table: %s\n",
 473                           share_mode_str(i, &entry)));
 474         }
 475 }
 476
 477 /*******************************************************************
 478  Get all share mode entries for a dev/inode pair.
 479 ********************************************************************/
 480
 481 static BOOL parse_share_modes(TDB_DATA dbuf, struct share_mode_lock *lck)
 482 {
 483         struct locking_data *data;
 484         int i;
 485
 486         if (dbuf.dsize < sizeof(struct locking_data)) {
 487                 smb_panic("PANIC: parse_share_modes: buffer too short.\n");
 488         }
 489
 490         data = (struct locking_data *)dbuf.dptr;
 491
 492         lck->delete_on_close = data->u.s.delete_on_close;
 493         lck->initial_delete_on_close = data->u.s.initial_delete_on_close;
 494         lck->num_share_modes = data->u.s.num_share_mode_entries;
 495
 496         DEBUG(10, ("parse_share_modes: delete_on_close: %d, "
 497                    "initial_delete_on_close: %d, "
 498                    "num_share_modes: %d\n",
 499                 lck->delete_on_close,
 500                 lck->initial_delete_on_close,
 501                 lck->num_share_modes));
 502
 503         if ((lck->num_share_modes < 0) || (lck->num_share_modes > 1000000)) {
 504                 DEBUG(0, ("invalid number of share modes: %d\n",
 505                           lck->num_share_modes));
 506                 smb_panic("PANIC: invalid number of share modes");
 507         }
 508
 509         lck->share_modes = NULL;
 510
 511         if (lck->num_share_modes != 0) {
 512
 513                 if (dbuf.dsize < (sizeof(struct locking_data) +
 514                                   (lck->num_share_modes *
 515                                    sizeof(struct share_mode_entry)))) {
 516                         smb_panic("PANIC: parse_share_modes: buffer too short.\n");
 517                 }
 518
 519                 lck->share_modes = talloc_memdup(lck, dbuf.dptr+sizeof(*data),
 520                                                  lck->num_share_modes *
 521                                                  sizeof(struct share_mode_entry));
 522
 523                 if (lck->share_modes == NULL) {
 524                         smb_panic("talloc failed\n");
 525                 }
 526         }
 527
 528         /* Get any delete token. */
 529         if (data->u.s.delete_token_size) {
 530                 char *p = dbuf.dptr + sizeof(*data) +
 531                                 (lck->num_share_modes *
 532                                 sizeof(struct share_mode_entry));
 533
 534                 if ((data->u.s.delete_token_size < sizeof(uid_t) + sizeof(gid_t)) ||
 535                                 ((data->u.s.delete_token_size - sizeof(uid_t)) % sizeof(gid_t)) != 0) {
 536                         DEBUG(0, ("parse_share_modes: invalid token size %d\n",
 537                                 data->u.s.delete_token_size));
 538                         smb_panic("parse_share_modes: invalid token size\n");
 539                 }
 540
 541                 lck->delete_token = TALLOC_P(lck, UNIX_USER_TOKEN);
 542                 if (!lck->delete_token) {
 543                         smb_panic("talloc failed\n");
 544                 }
 545
 546                 /* Copy out the uid and gid. */
 547                 memcpy(&lck->delete_token->uid, p, sizeof(uid_t));
 548                 p += sizeof(uid_t);
 549                 memcpy(&lck->delete_token->gid, p, sizeof(gid_t));
 550                 p += sizeof(gid_t);
 551
 552                 /* Any supplementary groups ? */
 553                 lck->delete_token->ngroups = (data->u.s.delete_token_size > (sizeof(uid_t) + sizeof(gid_t))) ?
 554                                         ((data->u.s.delete_token_size -
 555                                                 (sizeof(uid_t) + sizeof(gid_t)))/sizeof(gid_t)) : 0;
 556
 557                 if (lck->delete_token->ngroups) {
 558                         /* Make this a talloc child of lck->delete_token. */
 559                         lck->delete_token->groups = TALLOC_ARRAY(lck->delete_token, gid_t,
 560                                                         lck->delete_token->ngroups);
 561                         if (!lck->delete_token) {
 562                                 smb_panic("talloc failed\n");
 563                         }
 564
 565                         for (i = 0; i < lck->delete_token->ngroups; i++) {
 566                                 memcpy(&lck->delete_token->groups[i], p, sizeof(gid_t));
 567                                 p += sizeof(gid_t);
 568                         }
 569                 }
 570
 571         } else {
 572                 lck->delete_token = NULL;
 573         }
 574
 575         /* Save off the associated service path and filename. */
 576         lck->servicepath = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
 577                                         (lck->num_share_modes *
 578                                         sizeof(struct share_mode_entry)) +
 579                                         data->u.s.delete_token_size );
 580
 581         lck->filename = talloc_strdup(lck, dbuf.dptr + sizeof(*data) +
 582                                         (lck->num_share_modes *
 583                                         sizeof(struct share_mode_entry)) +
 584                                         data->u.s.delete_token_size +
 585                                         strlen(lck->servicepath) + 1 );
 586
 587         /*
 588          * Ensure that each entry has a real process attached.
 589          */
 590
 591         for (i = 0; i < lck->num_share_modes; i++) {
 592                 struct share_mode_entry *entry_p = &lck->share_modes[i];
 593                 DEBUG(10,("parse_share_modes: %s\n",
 594                           share_mode_str(i, entry_p) ));
 595                 if (!process_exists(entry_p->pid)) {
 596                         DEBUG(10,("parse_share_modes: deleted %s\n",
 597                                   share_mode_str(i, entry_p) ));
 598                         entry_p->op_type = UNUSED_SHARE_MODE_ENTRY;
 599                         lck->modified = True;
 600                 }
 601         }
 602
 603         return True;
 604 }
 605
 606 static TDB_DATA unparse_share_modes(struct share_mode_lock *lck)
 607 {
 608         TDB_DATA result;
 609         int num_valid = 0;
 610         int i;
 611         struct locking_data *data;
 612         ssize_t offset;
 613         ssize_t sp_len;
 614         uint32 delete_token_size;
 615
 616         result.dptr = NULL;
 617         result.dsize = 0;
 618
 619         for (i=0; i<lck->num_share_modes; i++) {
 620                 if (!is_unused_share_mode_entry(&lck->share_modes[i])) {
 621                         num_valid += 1;
 622                 }
 623         }
 624
 625         if (num_valid == 0) {
 626                 return result;
 627         }
 628
 629         sp_len = strlen(lck->servicepath);
 630         delete_token_size = (lck->delete_token ?
 631                         (sizeof(uid_t) + sizeof(gid_t) + (lck->delete_token->ngroups*sizeof(gid_t))) : 0);
 632
 633         result.dsize = sizeof(*data) +
 634                 lck->num_share_modes * sizeof(struct share_mode_entry) +
 635                 delete_token_size +
 636                 sp_len + 1 +
 637                 strlen(lck->filename) + 1;
 638         result.dptr = talloc_size(lck, result.dsize);
 639
 640         if (result.dptr == NULL) {
 641                 smb_panic("talloc failed\n");
 642         }
 643
 644         data = (struct locking_data *)result.dptr;
 645         ZERO_STRUCTP(data);
 646         data->u.s.num_share_mode_entries = lck->num_share_modes;
 647         data->u.s.delete_on_close = lck->delete_on_close;
 648         data->u.s.initial_delete_on_close = lck->initial_delete_on_close;
 649         data->u.s.delete_token_size = delete_token_size;
 650         DEBUG(10, ("unparse_share_modes: del: %d, initial del %d, tok = %u, num: %d\n",
 651                 data->u.s.delete_on_close,
 652                 data->u.s.initial_delete_on_close,
 653                 (unsigned int)data->u.s.delete_token_size,
 654                 data->u.s.num_share_mode_entries));
 655         memcpy(result.dptr + sizeof(*data), lck->share_modes,
 656                sizeof(struct share_mode_entry)*lck->num_share_modes);
 657         offset = sizeof(*data) +
 658                 sizeof(struct share_mode_entry)*lck->num_share_modes;
 659
 660         /* Store any delete on close token. */
 661         if (lck->delete_token) {
 662                 char *p = result.dptr + offset;
 663
 664                 memcpy(p, &lck->delete_token->uid, sizeof(uid_t));
 665                 p += sizeof(uid_t);
 666
 667                 memcpy(p, &lck->delete_token->gid, sizeof(gid_t));
 668
 669                 for (i = 0; i < lck->delete_token->ngroups; i++) {
 670                         memcpy(p, &lck->delete_token->groups[i], sizeof(gid_t));
 671                         p += sizeof(gid_t);
 672                 }
 673                 offset = p - result.dptr;
 674         }
 675
 676         safe_strcpy(result.dptr + offset, lck->servicepath,
 677                     result.dsize - offset - 1);
 678         offset += sp_len + 1;
 679         safe_strcpy(result.dptr + offset, lck->filename,
 680                     result.dsize - offset - 1);
 681
 682         if (DEBUGLEVEL >= 10) {
 683                 print_share_mode_table(data);
 684         }
 685
 686         return result;
 687 }
 688
 689 static int share_mode_lock_destructor(void *p)
 690 {
 691         struct share_mode_lock *lck =
 692                 talloc_get_type_abort(p, struct share_mode_lock);
 693         TDB_DATA key = locking_key(lck->dev, lck->ino);
 694         TDB_DATA data;
 695
 696         if (!lck->modified) {
 697                 goto done;
 698         }
 699
 700         data = unparse_share_modes(lck);
 701
 702         if (data.dptr == NULL) {
 703                 if (!lck->fresh) {
 704                         /* There has been an entry before, delete it */
 705                         if (tdb_delete(tdb, key) == -1) {
 706                                 smb_panic("Could not delete share entry\n");
 707                         }
 708                 }
 709                 goto done;
 710         }
 711
 712         if (tdb_store(tdb, key, data, TDB_REPLACE) == -1) {
 713                 smb_panic("Could not store share mode entry\n");
 714         }
 715
 716  done:
 717         tdb_chainunlock(tdb, key);
 718
 719         return 0;
 720 }
 721
 722 struct share_mode_lock *get_share_mode_lock(TALLOC_CTX *mem_ctx,
 723                                                 SMB_DEV_T dev, SMB_INO_T ino,
 724                                                 const char *servicepath,
 725                                                 const char *fname)
 726 {
 727         struct share_mode_lock *lck;
 728         TDB_DATA key = locking_key(dev, ino);
 729         TDB_DATA data;
 730
 731         lck = TALLOC_P(mem_ctx, struct share_mode_lock);
 732         if (lck == NULL) {
 733                 DEBUG(0, ("talloc failed\n"));
 734                 return NULL;
 735         }
 736
 737         /* Ensure we set every field here as the destructor must be
 738            valid even if parse_share_modes fails. */
 739
 740         lck->servicepath = NULL;
 741         lck->filename = NULL;
 742         lck->dev = dev;
 743         lck->ino = ino;
 744         lck->num_share_modes = 0;
 745         lck->share_modes = NULL;
 746         lck->delete_token = NULL;
 747         lck->delete_on_close = False;
 748         lck->initial_delete_on_close = False;
 749         lck->fresh = False;
 750         lck->modified = False;
 751
 752         if (tdb_chainlock(tdb, key) != 0) {
 753                 DEBUG(3, ("Could not lock share entry\n"));
 754                 TALLOC_FREE(lck);
 755                 return NULL;
 756         }
 757
 758         /* We must set the destructor immediately after the chainlock
 759            ensure the lock is cleaned up on any of the error return
 760            paths below. */
 761
 762         talloc_set_destructor(lck, share_mode_lock_destructor);
 763
 764         data = tdb_fetch(tdb, key);
 765         lck->fresh = (data.dptr == NULL);
 766
 767         if (lck->fresh) {
 768
 769                 if (fname == NULL || servicepath == NULL) {
 770                         TALLOC_FREE(lck);
 771                         return NULL;
 772                 }
 773                 lck->filename = talloc_strdup(lck, fname);
 774                 lck->servicepath = talloc_strdup(lck, servicepath);
 775                 if (lck->filename == NULL || lck->servicepath == NULL) {
 776                         DEBUG(0, ("talloc failed\n"));
 777                         TALLOC_FREE(lck);
 778                         return NULL;
 779                 }
 780         } else {
 781                 if (!parse_share_modes(data, lck)) {
 782                         DEBUG(0, ("Could not parse share modes\n"));
 783                         TALLOC_FREE(lck);
 784                         SAFE_FREE(data.dptr);
 785                         return NULL;
 786                 }
 787         }
 788
 789         SAFE_FREE(data.dptr);
 790
 791         return lck;
 792 }
 793
 794 /*******************************************************************
 795  Sets the service name and filename for rename.
 796  At this point we emit "file renamed" messages to all
 797  process id's that have this file open.
 798  Based on an initial code idea from SATOH Fumiyasu <fumiya@samba.gr.jp>
 799 ********************************************************************/
 800
 801 BOOL rename_share_filename(struct share_mode_lock *lck,
 802                         const char *servicepath,
 803                         const char *newname)
 804 {
 805         size_t sp_len;
 806         size_t fn_len;
 807         size_t msg_len;
 808         char *frm = NULL;
 809         int i;
 810
 811         if (!lck) {
 812                 return False;
 813         }
 814
 815         DEBUG(10, ("rename_share_filename: servicepath %s newname %s\n",
 816                 servicepath, newname));
 817
 818         /*
 819          * rename_internal_fsp() and rename_internals() add './' to
 820          * head of newname if newname does not contain a '/'.
 821          */
 822         while (newname[0] && newname[1] && newname[0] == '.' && newname[1] == '/') {
 823                 newname += 2;
 824         }
 825
 826         lck->servicepath = talloc_strdup(lck, servicepath);
 827         lck->filename = talloc_strdup(lck, newname);
 828         if (lck->filename == NULL || lck->servicepath == NULL) {
 829                 DEBUG(0, ("rename_share_filename: talloc failed\n"));
 830                 return False;
 831         }
 832         lck->modified = True;
 833
 834         sp_len = strlen(lck->servicepath);
 835         fn_len = strlen(lck->filename);
 836
 837         msg_len = MSG_FILE_RENAMED_MIN_SIZE + sp_len + 1 + fn_len + 1;
 838
 839         /* Set up the name changed message. */
 840         frm = TALLOC(lck, msg_len);
 841         if (!frm) {
 842                 return False;
 843         }
 844
 845         SDEV_T_VAL(frm,0,lck->dev);
 846         SINO_T_VAL(frm,8,lck->ino);
 847
 848         DEBUG(10,("rename_share_filename: msg_len = %d\n", msg_len ));
 849
 850         safe_strcpy(&frm[16], lck->servicepath, sp_len);
 851         safe_strcpy(&frm[16 + sp_len + 1], lck->filename, fn_len);
 852
 853         /* Send the messages. */
 854         for (i=0; i<lck->num_share_modes; i++) {
 855                 struct share_mode_entry *se = &lck->share_modes[i];
 856                 if (!is_valid_share_mode_entry(se)) {
 857                         continue;
 858                 }
 859                 /* But not to ourselves... */
 860                 if (procid_is_me(&se->pid)) {
 861                         continue;
 862                 }
 863
 864                 DEBUG(10,("rename_share_filename: sending rename message to pid %u "
 865                         "dev %x, inode  %.0f sharepath %s newname %s\n",
 866                         (unsigned int)procid_to_pid(&se->pid),
 867                         (unsigned int)lck->dev, (double)lck->ino,
 868                         lck->servicepath, lck->filename ));
 869
 870                 become_root();
 871                 message_send_pid(se->pid, MSG_SMB_FILE_RENAME,
 872                                 frm, msg_len, True);
 873                 unbecome_root();
 874         }
 875
 876         return True;
 877 }
 878
 879 BOOL get_delete_on_close_flag(SMB_DEV_T dev, SMB_INO_T inode)
 880 {
 881         BOOL result;
 882         struct share_mode_lock *lck = get_share_mode_lock(NULL, dev, inode, NULL, NULL);
 883         if (!lck) {
 884                 return False;
 885         }
 886         result = lck->delete_on_close;
 887         TALLOC_FREE(lck);
 888         return result;
 889 }
 890
 891 BOOL is_valid_share_mode_entry(const struct share_mode_entry *e)
 892 {
 893         int num_props = 0;
 894
 895         num_props += ((e->op_type == NO_OPLOCK) ? 1 : 0);
 896         num_props += (EXCLUSIVE_OPLOCK_TYPE(e->op_type) ? 1 : 0);
 897         num_props += (LEVEL_II_OPLOCK_TYPE(e->op_type) ? 1 : 0);
 898
 899         SMB_ASSERT(num_props <= 1);
 900         return (num_props != 0);
 901 }
 902
 903 BOOL is_deferred_open_entry(const struct share_mode_entry *e)
 904 {
 905         return (e->op_type == DEFERRED_OPEN_ENTRY);
 906 }
 907
 908 BOOL is_unused_share_mode_entry(const struct share_mode_entry *e)
 909 {
 910         return (e->op_type == UNUSED_SHARE_MODE_ENTRY);
 911 }
 912
 913 /*******************************************************************
 914  Fill a share mode entry.
 915 ********************************************************************/
 916
 917 static void fill_share_mode_entry(struct share_mode_entry *e,
 918                                   files_struct *fsp,
 919                                   uint16 mid, uint16 op_type)
 920 {
 921         ZERO_STRUCTP(e);
 922         e->pid = procid_self();
 923         e->share_access = fsp->share_access;
 924         e->private_options = fsp->fh->private_options;
 925         e->access_mask = fsp->access_mask;
 926         e->op_mid = mid;
 927         e->op_type = op_type;
 928         e->time.tv_sec = fsp->open_time.tv_sec;
 929         e->time.tv_usec = fsp->open_time.tv_usec;
 930         e->share_file_id = fsp->file_id;
 931         e->dev = fsp->dev;
 932         e->inode = fsp->inode;
 933 }
 934
 935 static void fill_deferred_open_entry(struct share_mode_entry *e,
 936                                      const struct timeval request_time,
 937                                      SMB_DEV_T dev, SMB_INO_T ino, uint16 mid)
 938 {
 939         ZERO_STRUCTP(e);
 940         e->pid = procid_self();
 941         e->op_mid = mid;
 942         e->op_type = DEFERRED_OPEN_ENTRY;
 943         e->time.tv_sec = request_time.tv_sec;
 944         e->time.tv_usec = request_time.tv_usec;
 945         e->dev = dev;
 946         e->inode = ino;
 947 }
 948
 949 static void add_share_mode_entry(struct share_mode_lock *lck,
 950                                  const struct share_mode_entry *entry)
 951 {
 952         int i;
 953
 954         for (i=0; i<lck->num_share_modes; i++) {
 955                 struct share_mode_entry *e = &lck->share_modes[i];
 956                 if (is_unused_share_mode_entry(e)) {
 957                         *e = *entry;
 958                         break;
 959                 }
 960         }
 961
 962         if (i == lck->num_share_modes) {
 963                 /* No unused entry found */
 964                 ADD_TO_ARRAY(lck, struct share_mode_entry, *entry,
 965                              &lck->share_modes, &lck->num_share_modes);
 966         }
 967         lck->modified = True;
 968 }
 969
 970 void set_share_mode(struct share_mode_lock *lck, files_struct *fsp,
 971                     uint16 mid, uint16 op_type)
 972 {
 973         struct share_mode_entry entry;
 974         fill_share_mode_entry(&entry, fsp, mid, op_type);
 975         add_share_mode_entry(lck, &entry);
 976 }
 977
 978 void add_deferred_open(struct share_mode_lock *lck, uint16 mid,
 979                        struct timeval request_time,
 980                        SMB_DEV_T dev, SMB_INO_T ino)
 981 {
 982         struct share_mode_entry entry;
 983         fill_deferred_open_entry(&entry, request_time, dev, ino, mid);
 984         add_share_mode_entry(lck, &entry);
 985 }
 986
 987 /*******************************************************************
 988  Check if two share mode entries are identical, ignoring oplock
 989  and mid info and desired_access.
 990 ********************************************************************/
 991
 992 static BOOL share_modes_identical(struct share_mode_entry *e1,
 993                                   struct share_mode_entry *e2)
 994 {
 995 #if 1 /* JRA PARANOIA TEST - REMOVE LATER */
 996         if (procid_equal(&e1->pid, &e2->pid) &&
 997             e1->share_file_id == e2->share_file_id &&
 998             e1->dev == e2->dev &&
 999             e1->inode == e2->inode &&
1000             (e1->share_access) != (e2->share_access)) {
1001                 DEBUG(0,("PANIC: share_modes_identical: share_mode "
1002                          "mismatch (e1 = 0x%x, e2 = 0x%x). Logic error.\n",
1003                          (unsigned int)e1->share_access,
1004                          (unsigned int)e2->share_access ));
1005                 smb_panic("PANIC: share_modes_identical logic error.\n");
1006         }
1007 #endif
1008
1009         return (procid_equal(&e1->pid, &e2->pid) &&
1010                 (e1->share_access) == (e2->share_access) &&
1011                 e1->dev == e2->dev &&
1012                 e1->inode == e2->inode &&
1013                 e1->share_file_id == e2->share_file_id );
1014 }
1015
1016 static BOOL deferred_open_identical(struct share_mode_entry *e1,
1017                                     struct share_mode_entry *e2)
1018 {
1019         return (procid_equal(&e1->pid, &e2->pid) &&
1020                 (e1->op_mid == e2->op_mid) &&
1021                 (e1->dev == e2->dev) &&
1022                 (e1->inode == e2->inode));
1023 }
1024
1025 static struct share_mode_entry *find_share_mode_entry(struct share_mode_lock *lck,
1026                                                       struct share_mode_entry *entry)
1027 {
1028         int i;
1029
1030         for (i=0; i<lck->num_share_modes; i++) {
1031                 struct share_mode_entry *e = &lck->share_modes[i];
1032                 if (is_valid_share_mode_entry(entry) &&
1033                     is_valid_share_mode_entry(e) &&
1034                     share_modes_identical(e, entry)) {
1035                         return e;
1036                 }
1037                 if (is_deferred_open_entry(entry) &&
1038                     is_deferred_open_entry(e) &&
1039                     deferred_open_identical(e, entry)) {
1040                         return e;
1041                 }
1042         }
1043         return NULL;
1044 }
1045
1046 /*******************************************************************
1047  Del the share mode of a file for this process. Return the number of
1048  entries left.
1049 ********************************************************************/
1050
1051 BOOL del_share_mode(struct share_mode_lock *lck, files_struct *fsp)
1052 {
1053         struct share_mode_entry entry, *e;
1054
1055         fill_share_mode_entry(&entry, fsp, 0, NO_OPLOCK);
1056
1057         e = find_share_mode_entry(lck, &entry);
1058         if (e == NULL) {
1059                 return False;
1060         }
1061
1062         e->op_type = UNUSED_SHARE_MODE_ENTRY;
1063         lck->modified = True;
1064         return True;
1065 }
1066
1067 void del_deferred_open_entry(struct share_mode_lock *lck, uint16 mid)
1068 {
1069         struct share_mode_entry entry, *e;
1070
1071         fill_deferred_open_entry(&entry, timeval_zero(),
1072                                  lck->dev, lck->ino, mid);
1073
1074         e = find_share_mode_entry(lck, &entry);
1075         if (e == NULL) {
1076                 return;
1077         }
1078
1079         e->op_type = UNUSED_SHARE_MODE_ENTRY;
1080         lck->modified = True;
1081 }
1082
1083 /*******************************************************************
1084  Remove an oplock mid and mode entry from a share mode.
1085 ********************************************************************/
1086
1087 BOOL remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
1088 {
1089         struct share_mode_entry entry, *e;
1090
1091         fill_share_mode_entry(&entry, fsp, 0, NO_OPLOCK);
1092
1093         e = find_share_mode_entry(lck, &entry);
1094         if (e == NULL) {
1095                 return False;
1096         }
1097
1098         e->op_mid = 0;
1099         e->op_type = NO_OPLOCK;
1100         lck->modified = True;
1101         return True;
1102 }
1103
1104 /*******************************************************************
1105  Downgrade a oplock type from exclusive to level II.
1106 ********************************************************************/
1107
1108 BOOL downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
1109 {
1110         struct share_mode_entry entry, *e;
1111
1112         fill_share_mode_entry(&entry, fsp, 0, NO_OPLOCK);
1113
1114         e = find_share_mode_entry(lck, &entry);
1115         if (e == NULL) {
1116                 return False;
1117         }
1118
1119         e->op_type = LEVEL_II_OPLOCK;
1120         lck->modified = True;
1121         return True;
1122 }
1123
1124 /****************************************************************************
1125  Deal with the internal needs of setting the delete on close flag. Note that
1126  as the tdb locking is recursive, it is safe to call this from within
1127  open_file_shared. JRA.
1128 ****************************************************************************/
1129
1130 NTSTATUS can_set_delete_on_close(files_struct *fsp, BOOL delete_on_close,
1131                                  uint32 dosmode)
1132 {
1133         if (!delete_on_close) {
1134                 return NT_STATUS_OK;
1135         }
1136
1137         /*
1138          * Only allow delete on close for writable files.
1139          */
1140
1141         if ((dosmode & aRONLY) &&
1142             !lp_delete_readonly(SNUM(fsp->conn))) {
1143                 DEBUG(10,("can_set_delete_on_close: file %s delete on close "
1144                           "flag set but file attribute is readonly.\n",
1145                           fsp->fsp_name ));
1146                 return NT_STATUS_CANNOT_DELETE;
1147         }
1148
1149         /*
1150          * Only allow delete on close for writable shares.
1151          */
1152
1153         if (!CAN_WRITE(fsp->conn)) {
1154                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
1155                           "close flag set but write access denied on share.\n",
1156                           fsp->fsp_name ));
1157                 return NT_STATUS_ACCESS_DENIED;
1158         }
1159
1160         /*
1161          * Only allow delete on close for files/directories opened with delete
1162          * intent.
1163          */
1164
1165         if (!(fsp->access_mask & DELETE_ACCESS)) {
1166                 DEBUG(10,("can_set_delete_on_close: file %s delete on "
1167                           "close flag set but delete access denied.\n",
1168                           fsp->fsp_name ));
1169                 return NT_STATUS_ACCESS_DENIED;
1170         }
1171
1172         return NT_STATUS_OK;
1173 }
1174
1175 /*************************************************************************
1176  Return a talloced copy of a UNIX_USER_TOKEN. NULL on fail.
1177  (Should this be in locking.c.... ?).
1178 *************************************************************************/
1179
1180 static UNIX_USER_TOKEN *copy_unix_token(TALLOC_CTX *ctx, UNIX_USER_TOKEN *tok)
1181 {
1182         UNIX_USER_TOKEN *cpy;
1183
1184         if (tok == NULL) {
1185                 return NULL;
1186         }
1187
1188         cpy = TALLOC_P(ctx, UNIX_USER_TOKEN);
1189         if (!cpy) {
1190                 return NULL;
1191         }
1192
1193         cpy->uid = tok->uid;
1194         cpy->gid = tok->gid;
1195         cpy->ngroups = tok->ngroups;
1196         if (tok->ngroups) {
1197                 /* Make this a talloc child of cpy. */
1198                 cpy->groups = TALLOC_ARRAY(cpy, gid_t, tok->ngroups);
1199                 if (!cpy->groups) {
1200                         return NULL;
1201                 }
1202                 memcpy(cpy->groups, tok->groups, tok->ngroups * sizeof(gid_t));
1203         }
1204         return cpy;
1205 }
1206
1207 /****************************************************************************
1208  Replace the delete on close token.
1209 ****************************************************************************/
1210
1211 void set_delete_on_close_token(struct share_mode_lock *lck, UNIX_USER_TOKEN *tok)
1212 {
1213         /* Ensure there's no token. */
1214         if (lck->delete_token) {
1215                 TALLOC_FREE(lck->delete_token); /* Also deletes groups... */
1216                 lck->delete_token = NULL;
1217         }
1218
1219         /* Copy the new token (can be NULL). */
1220         lck->delete_token = copy_unix_token(lck, tok);
1221         lck->modified = True;
1222 }
1223
1224 /****************************************************************************
1225  Sets the delete on close flag over all share modes on this file.
1226  Modify the share mode entry for all files open
1227  on this device and inode to tell other smbds we have
1228  changed the delete on close flag. This will be noticed
1229  in the close code, the last closer will delete the file
1230  if flag is set.
1231  Note that setting this to any value clears the initial_delete_on_close flag.
1232  If delete_on_close is True this makes a copy of any UNIX_USER_TOKEN into the
1233  lck entry.
1234 ****************************************************************************/
1235
1236 BOOL set_delete_on_close(files_struct *fsp, BOOL delete_on_close, UNIX_USER_TOKEN *tok)
1237 {
1238         struct share_mode_lock *lck;
1239
1240         DEBUG(10,("set_delete_on_close: %s delete on close flag for "
1241                   "fnum = %d, file %s\n",
1242                   delete_on_close ? "Adding" : "Removing", fsp->fnum,
1243                   fsp->fsp_name ));
1244
1245         if (fsp->is_stat) {
1246                 return True;
1247         }
1248
1249         lck = get_share_mode_lock(NULL, fsp->dev, fsp->inode, NULL, NULL);
1250         if (lck == NULL) {
1251                 return False;
1252         }
1253
1254         if (lck->delete_on_close != delete_on_close) {
1255                 set_delete_on_close_token(lck, tok);
1256                 lck->delete_on_close = delete_on_close;
1257                 if (delete_on_close) {
1258                         SMB_ASSERT(lck->delete_token != NULL);
1259                 }
1260                 lck->modified = True;
1261         }
1262
1263         if (lck->initial_delete_on_close) {
1264                 lck->initial_delete_on_close = False;
1265                 lck->modified = True;
1266         }
1267
1268         TALLOC_FREE(lck);
1269         return True;
1270 }
1271
1272 static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf,
1273                        void *state)
1274 {
1275         struct locking_data *data;
1276         struct share_mode_entry *shares;
1277         const char *sharepath;
1278         const char *fname;
1279         int i;
1280         void (*traverse_callback)(struct share_mode_entry *, const char *, const char *) = state;
1281
1282         /* Ensure this is a locking_key record. */
1283         if (kbuf.dsize != sizeof(struct locking_key))
1284                 return 0;
1285
1286         data = (struct locking_data *)dbuf.dptr;
1287         shares = (struct share_mode_entry *)(dbuf.dptr + sizeof(*data));
1288         sharepath = dbuf.dptr + sizeof(*data) +
1289                 data->u.s.num_share_mode_entries*sizeof(*shares) +
1290                 data->u.s.delete_token_size;
1291         fname = dbuf.dptr + sizeof(*data) +
1292                 data->u.s.num_share_mode_entries*sizeof(*shares) +
1293                 data->u.s.delete_token_size +
1294                 strlen(sharepath) + 1;
1295
1296         for (i=0;i<data->u.s.num_share_mode_entries;i++) {
1297                 traverse_callback(&shares[i], sharepath, fname);
1298         }
1299         return 0;
1300 }
1301
1302 /*******************************************************************
1303  Call the specified function on each entry under management by the
1304  share mode system.
1305 ********************************************************************/
1306
1307 int share_mode_forall(void (*fn)(const struct share_mode_entry *, const char *, const char *))
1308 {
1309         if (tdb == NULL)
1310                 return 0;
1311         return tdb_traverse(tdb, traverse_fn, fn);
1312 }