2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 1992-2000
5 Copyright (C) Jeremy Allison 1992-2006
6 Copyright (C) Volker Lendecke 2005
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
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.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 12 aug 96: Erik.Devriendt@te6.siemens.be
24 added support for shared memory implementation of share mode locking
26 May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
27 locking to deal with multiple share modes per open file.
29 September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
32 rewritten completely to use new tdb code. Tridge, Dec '99
34 Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
35 Added Unix Extensions POSIX locking support. Jeremy Allison Mar 2006.
39 #include "system/filesys.h"
40 #include "locking/proto.h"
41 #include "smbd/globals.h"
42 #include "dbwrap/dbwrap.h"
43 #include "dbwrap/dbwrap_open.h"
44 #include "../libcli/security/security.h"
48 #include "../librpc/gen_ndr/ndr_open_files.h"
51 #define DBGC_CLASS DBGC_LOCKING
53 #define NO_LOCKING_COUNT (-1)
55 /* the locking database handle */
56 static struct db_context *lock_db;
58 static bool locking_init_internal(bool read_only)
65 lock_db = db_open(NULL, lock_path("locking.tdb"),
66 lp_open_files_db_hash_size(),
67 TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
68 read_only?O_RDONLY:O_RDWR|O_CREAT, 0644,
72 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
76 if (!posix_locking_init(read_only))
82 bool locking_init(void)
84 return locking_init_internal(false);
87 bool locking_init_readonly(void)
89 return locking_init_internal(true);
92 /*******************************************************************
93 Deinitialize the share_mode management.
94 ******************************************************************/
96 bool locking_end(void)
103 /*******************************************************************
104 Form a static locking key for a dev/inode pair.
105 ******************************************************************/
107 static TDB_DATA locking_key(const struct file_id *id, struct file_id *tmp)
110 return make_tdb_data((const uint8_t *)tmp, sizeof(*tmp));
113 /*******************************************************************
114 Get all share mode entries for a dev/inode pair.
115 ********************************************************************/
117 static struct share_mode_data *parse_share_modes(TALLOC_CTX *mem_ctx,
120 struct share_mode_data *d;
122 struct server_id *pids;
124 enum ndr_err_code ndr_err;
127 d = talloc_zero(mem_ctx, struct share_mode_data);
129 DEBUG(0, ("talloc failed\n"));
133 blob.data = dbuf.dptr;
134 blob.length = dbuf.dsize;
136 ndr_err = ndr_pull_struct_blob(
137 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
138 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
139 DEBUG(1, ("ndr_pull_share_mode_lock failed\n"));
146 if (DEBUGLEVEL >= 10) {
147 DEBUG(10, ("parse_share_modes:\n"));
148 NDR_PRINT_DEBUG(share_mode_data, d);
152 * Ensure that each entry has a real process attached.
155 pids = talloc_array(talloc_tos(), struct server_id,
158 DEBUG(0, ("talloc failed\n"));
161 pid_exists = talloc_array(talloc_tos(), bool, d->num_share_modes);
162 if (pid_exists == NULL) {
163 DEBUG(0, ("talloc failed\n"));
167 for (i=0; i<d->num_share_modes; i++) {
168 pids[i] = d->share_modes[i].pid;
170 if (!serverids_exist(pids, d->num_share_modes, pid_exists)) {
171 DEBUG(0, ("serverid_exists failed\n"));
176 while (i < d->num_share_modes) {
177 struct share_mode_entry *e = &d->share_modes[i];
178 if (!pid_exists[i]) {
179 *e = d->share_modes[d->num_share_modes-1];
180 d->num_share_modes -= 1;
186 TALLOC_FREE(pid_exists);
194 /*******************************************************************
195 Create a storable data blob from a modified share_mode_data struct.
196 ********************************************************************/
198 static TDB_DATA unparse_share_modes(struct share_mode_data *d)
201 enum ndr_err_code ndr_err;
203 if (DEBUGLEVEL >= 10) {
204 DEBUG(10, ("unparse_share_modes:\n"));
205 NDR_PRINT_DEBUG(share_mode_data, d);
208 if (d->num_share_modes == 0) {
209 DEBUG(10, ("No used share mode found\n"));
210 return make_tdb_data(NULL, 0);
213 ndr_err = ndr_push_struct_blob(
214 &blob, d, d, (ndr_push_flags_fn_t)ndr_push_share_mode_data);
215 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
216 smb_panic("ndr_push_share_mode_lock failed");
219 return make_tdb_data(blob.data, blob.length);
222 /*******************************************************************
223 If modified, store the share_mode_data back into the database.
224 ********************************************************************/
226 static int share_mode_data_destructor(struct share_mode_data *d)
235 data = unparse_share_modes(d);
237 if (data.dptr == NULL) {
239 /* There has been an entry before, delete it */
241 status = dbwrap_record_delete(d->record);
242 if (!NT_STATUS_IS_OK(status)) {
245 DEBUG(0, ("delete_rec returned %s\n",
248 if (asprintf(&errmsg, "could not delete share "
250 nt_errstr(status)) == -1) {
251 smb_panic("could not delete share"
260 status = dbwrap_record_store(d->record, data, TDB_REPLACE);
261 if (!NT_STATUS_IS_OK(status)) {
264 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
266 if (asprintf(&errmsg, "could not store share mode entry: %s",
267 nt_errstr(status)) == -1) {
268 smb_panic("could not store share mode entry");
278 /*******************************************************************
279 Allocate a new share_mode_data struct, mark it unmodified.
280 fresh is set to note that currently there is no database entry.
281 ********************************************************************/
283 static struct share_mode_data *fresh_share_mode_lock(
284 TALLOC_CTX *mem_ctx, const char *servicepath,
285 const struct smb_filename *smb_fname,
286 const struct timespec *old_write_time)
288 struct share_mode_data *d;
290 if ((servicepath == NULL) || (smb_fname == NULL) ||
291 (old_write_time == NULL)) {
295 d = talloc_zero(mem_ctx, struct share_mode_data);
299 d->base_name = talloc_strdup(d, smb_fname->base_name);
300 if (d->base_name == NULL) {
303 if (smb_fname->stream_name != NULL) {
304 d->stream_name = talloc_strdup(d, smb_fname->stream_name);
305 if (d->stream_name == NULL) {
309 d->servicepath = talloc_strdup(d, servicepath);
310 if (d->servicepath == NULL) {
313 d->old_write_time = *old_write_time;
318 DEBUG(0, ("talloc failed\n"));
323 /*******************************************************************
324 Either fetch a share mode from the database, or allocate a fresh
325 one if the record doesn't exist.
326 ********************************************************************/
328 static struct share_mode_lock *get_share_mode_lock_internal(
329 TALLOC_CTX *mem_ctx, const struct file_id id,
330 const char *servicepath, const struct smb_filename *smb_fname,
331 const struct timespec *old_write_time)
333 struct share_mode_lock *lck;
334 struct share_mode_data *d;
336 struct db_record *rec;
337 TDB_DATA key = locking_key(&id, &tmp);
340 rec = dbwrap_fetch_locked(lock_db, mem_ctx, key);
342 DEBUG(3, ("Could not lock share entry\n"));
346 value = dbwrap_record_get_value(rec);
348 if (value.dptr == NULL) {
349 d = fresh_share_mode_lock(mem_ctx, servicepath, smb_fname,
352 d = parse_share_modes(mem_ctx, value);
356 DEBUG(1, ("Could not get share mode lock\n"));
361 d->record = talloc_move(d, &rec);
362 talloc_set_destructor(d, share_mode_data_destructor);
364 lck = talloc(mem_ctx, struct share_mode_lock);
366 DEBUG(1, ("talloc failed\n"));
370 lck->data = talloc_move(lck, &d);
375 * We can only ever have one share mode locked. Users of
376 * get_share_mode_lock never see this, it will be refcounted by
379 static struct share_mode_lock *the_lock;
381 static int the_lock_destructor(struct share_mode_lock *l)
387 /*******************************************************************
388 Get a share_mode_lock, Reference counted to allow nexted calls.
389 ********************************************************************/
391 struct share_mode_lock *get_share_mode_lock_fresh(
393 const struct file_id id,
394 const char *servicepath,
395 const struct smb_filename *smb_fname,
396 const struct timespec *old_write_time)
398 TALLOC_CTX *frame = talloc_stackframe();
400 struct share_mode_lock *lck;
402 if (the_lock == NULL) {
403 the_lock = get_share_mode_lock_internal(
404 frame, id, servicepath, smb_fname, old_write_time);
405 if (the_lock == NULL) {
408 talloc_set_destructor(the_lock, the_lock_destructor);
410 if (!file_id_equal(&the_lock->data->id, &id)) {
411 DEBUG(1, ("Can not lock two share modes simultaneously\n"));
414 lck = talloc(mem_ctx, struct share_mode_lock);
416 DEBUG(1, ("talloc failed\n"));
419 if (talloc_reference(lck, the_lock) == NULL) {
420 DEBUG(1, ("talloc_reference failed\n"));
423 lck->data = the_lock->data;
431 /*******************************************************************
432 Get a share_mode_lock without locking the database or reference
433 counting. Used by smbstatus to display existing share modes.
434 ********************************************************************/
436 struct share_mode_lock *fetch_share_mode_unlocked(TALLOC_CTX *mem_ctx,
437 const struct file_id id)
439 struct share_mode_lock *lck;
441 TDB_DATA key = locking_key(&id, &tmp);
445 status = dbwrap_fetch(lock_db, talloc_tos(), key, &data);
446 if (!NT_STATUS_IS_OK(status)) {
447 DEBUG(3, ("Could not fetch share entry\n"));
450 if (data.dptr == NULL) {
453 lck = talloc(mem_ctx, struct share_mode_lock);
455 TALLOC_FREE(data.dptr);
458 lck->data = parse_share_modes(lck, data);
459 TALLOC_FREE(data.dptr);
460 if (lck->data == NULL) {
467 struct forall_state {
468 void (*fn)(const struct share_mode_entry *entry,
469 const char *sharepath,
475 static int traverse_fn(struct db_record *rec, void *_state)
477 struct forall_state *state = (struct forall_state *)_state;
482 enum ndr_err_code ndr_err;
483 struct share_mode_data *d;
485 key = dbwrap_record_get_key(rec);
486 value = dbwrap_record_get_value(rec);
488 /* Ensure this is a locking_key record. */
489 if (key.dsize != sizeof(struct file_id))
492 d = talloc(talloc_tos(), struct share_mode_data);
497 blob.data = value.dptr;
498 blob.length = value.dsize;
500 ndr_err = ndr_pull_struct_blob(
501 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
502 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
503 DEBUG(1, ("ndr_pull_share_mode_lock failed\n"));
506 for (i=0; i<d->num_share_modes; i++) {
507 state->fn(&d->share_modes[i],
508 d->servicepath, d->base_name,
509 state->private_data);
516 /*******************************************************************
517 Call the specified function on each entry under management by the
519 ********************************************************************/
521 int share_mode_forall(void (*fn)(const struct share_mode_entry *, const char *,
522 const char *, void *),
525 struct forall_state state;
533 state.private_data = private_data;
535 status = dbwrap_traverse_read(lock_db, traverse_fn, (void *)&state,
538 if (!NT_STATUS_IS_OK(status)) {