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);
71 DEBUG(0,("ERROR: Failed to initialise locking database\n"));
75 if (!posix_locking_init(read_only))
81 bool locking_init(void)
83 return locking_init_internal(false);
86 bool locking_init_readonly(void)
88 return locking_init_internal(true);
91 /*******************************************************************
92 Deinitialize the share_mode management.
93 ******************************************************************/
95 bool locking_end(void)
102 /*******************************************************************
103 Form a static locking key for a dev/inode pair.
104 ******************************************************************/
106 static TDB_DATA locking_key(const struct file_id *id, struct file_id *tmp)
109 return make_tdb_data((const uint8_t *)tmp, sizeof(*tmp));
112 /*******************************************************************
113 Get all share mode entries for a dev/inode pair.
114 ********************************************************************/
116 static struct share_mode_data *parse_share_modes(TALLOC_CTX *mem_ctx,
119 struct share_mode_data *d;
121 struct server_id *pids;
123 enum ndr_err_code ndr_err;
126 d = talloc_zero(mem_ctx, struct share_mode_data);
128 DEBUG(0, ("talloc failed\n"));
132 blob.data = dbuf.dptr;
133 blob.length = dbuf.dsize;
135 ndr_err = ndr_pull_struct_blob(
136 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
137 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
138 DEBUG(1, ("ndr_pull_share_mode_lock failed\n"));
145 if (DEBUGLEVEL >= 10) {
146 DEBUG(10, ("parse_share_modes:\n"));
147 NDR_PRINT_DEBUG(share_mode_data, d);
151 * Ensure that each entry has a real process attached.
154 pids = talloc_array(talloc_tos(), struct server_id,
157 DEBUG(0, ("talloc failed\n"));
160 pid_exists = talloc_array(talloc_tos(), bool, d->num_share_modes);
161 if (pid_exists == NULL) {
162 DEBUG(0, ("talloc failed\n"));
166 for (i=0; i<d->num_share_modes; i++) {
167 pids[i] = d->share_modes[i].pid;
169 if (!serverids_exist(pids, d->num_share_modes, pid_exists)) {
170 DEBUG(0, ("serverid_exists failed\n"));
175 while (i < d->num_share_modes) {
176 struct share_mode_entry *e = &d->share_modes[i];
177 if (!pid_exists[i]) {
178 *e = d->share_modes[d->num_share_modes-1];
179 d->num_share_modes -= 1;
185 TALLOC_FREE(pid_exists);
193 /*******************************************************************
194 Create a storable data blob from a modified share_mode_data struct.
195 ********************************************************************/
197 static TDB_DATA unparse_share_modes(struct share_mode_data *d)
200 enum ndr_err_code ndr_err;
202 if (DEBUGLEVEL >= 10) {
203 DEBUG(10, ("unparse_share_modes:\n"));
204 NDR_PRINT_DEBUG(share_mode_data, d);
207 if (d->num_share_modes == 0) {
208 DEBUG(10, ("No used share mode found\n"));
209 return make_tdb_data(NULL, 0);
212 ndr_err = ndr_push_struct_blob(
213 &blob, d, d, (ndr_push_flags_fn_t)ndr_push_share_mode_data);
214 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
215 smb_panic("ndr_push_share_mode_lock failed");
218 return make_tdb_data(blob.data, blob.length);
221 /*******************************************************************
222 If modified, store the share_mode_data back into the database.
223 ********************************************************************/
225 static int share_mode_data_destructor(struct share_mode_data *d)
234 data = unparse_share_modes(d);
236 if (data.dptr == NULL) {
238 /* There has been an entry before, delete it */
240 status = dbwrap_record_delete(d->record);
241 if (!NT_STATUS_IS_OK(status)) {
244 DEBUG(0, ("delete_rec returned %s\n",
247 if (asprintf(&errmsg, "could not delete share "
249 nt_errstr(status)) == -1) {
250 smb_panic("could not delete share"
259 status = dbwrap_record_store(d->record, data, TDB_REPLACE);
260 if (!NT_STATUS_IS_OK(status)) {
263 DEBUG(0, ("store returned %s\n", nt_errstr(status)));
265 if (asprintf(&errmsg, "could not store share mode entry: %s",
266 nt_errstr(status)) == -1) {
267 smb_panic("could not store share mode entry");
277 /*******************************************************************
278 Allocate a new share_mode_data struct, mark it unmodified.
279 fresh is set to note that currently there is no database entry.
280 ********************************************************************/
282 static struct share_mode_data *fresh_share_mode_lock(
283 TALLOC_CTX *mem_ctx, const char *servicepath,
284 const struct smb_filename *smb_fname,
285 const struct timespec *old_write_time)
287 struct share_mode_data *d;
289 if ((servicepath == NULL) || (smb_fname == NULL) ||
290 (old_write_time == NULL)) {
294 d = talloc_zero(mem_ctx, struct share_mode_data);
298 d->base_name = talloc_strdup(d, smb_fname->base_name);
299 if (d->base_name == NULL) {
302 if (smb_fname->stream_name != NULL) {
303 d->stream_name = talloc_strdup(d, smb_fname->stream_name);
304 if (d->stream_name == NULL) {
308 d->servicepath = talloc_strdup(d, servicepath);
309 if (d->servicepath == NULL) {
312 d->old_write_time = *old_write_time;
317 DEBUG(0, ("talloc failed\n"));
322 /*******************************************************************
323 Either fetch a share mode from the database, or allocate a fresh
324 one if the record doesn't exist.
325 ********************************************************************/
327 static struct share_mode_lock *get_share_mode_lock_internal(
328 TALLOC_CTX *mem_ctx, const struct file_id id,
329 const char *servicepath, const struct smb_filename *smb_fname,
330 const struct timespec *old_write_time)
332 struct share_mode_lock *lck;
333 struct share_mode_data *d;
335 struct db_record *rec;
336 TDB_DATA key = locking_key(&id, &tmp);
339 rec = dbwrap_fetch_locked(lock_db, mem_ctx, key);
341 DEBUG(3, ("Could not lock share entry\n"));
345 value = dbwrap_record_get_value(rec);
347 if (value.dptr == NULL) {
348 d = fresh_share_mode_lock(mem_ctx, servicepath, smb_fname,
351 d = parse_share_modes(mem_ctx, value);
355 DEBUG(1, ("Could not get share mode lock\n"));
360 d->record = talloc_move(d, &rec);
361 talloc_set_destructor(d, share_mode_data_destructor);
363 lck = talloc(mem_ctx, struct share_mode_lock);
365 DEBUG(1, ("talloc failed\n"));
369 lck->data = talloc_move(lck, &d);
374 * We can only ever have one share mode locked. Users of
375 * get_share_mode_lock never see this, it will be refcounted by
378 static struct share_mode_lock *the_lock;
380 static int the_lock_destructor(struct share_mode_lock *l)
386 /*******************************************************************
387 Get a share_mode_lock, Reference counted to allow nexted calls.
388 ********************************************************************/
390 struct share_mode_lock *get_share_mode_lock_fresh(
392 const struct file_id id,
393 const char *servicepath,
394 const struct smb_filename *smb_fname,
395 const struct timespec *old_write_time)
397 TALLOC_CTX *frame = talloc_stackframe();
399 struct share_mode_lock *lck;
401 if (the_lock == NULL) {
402 the_lock = get_share_mode_lock_internal(
403 frame, id, servicepath, smb_fname, old_write_time);
404 if (the_lock == NULL) {
407 talloc_set_destructor(the_lock, the_lock_destructor);
409 if (!file_id_equal(&the_lock->data->id, &id)) {
410 DEBUG(1, ("Can not lock two share modes simultaneously\n"));
413 lck = talloc(mem_ctx, struct share_mode_lock);
415 DEBUG(1, ("talloc failed\n"));
418 if (talloc_reference(lck, the_lock) == NULL) {
419 DEBUG(1, ("talloc_reference failed\n"));
422 lck->data = the_lock->data;
430 /*******************************************************************
431 Get a share_mode_lock without locking the database or reference
432 counting. Used by smbstatus to display existing share modes.
433 ********************************************************************/
435 struct share_mode_lock *fetch_share_mode_unlocked(TALLOC_CTX *mem_ctx,
436 const struct file_id id)
438 struct share_mode_lock *lck;
440 TDB_DATA key = locking_key(&id, &tmp);
444 status = dbwrap_fetch(lock_db, talloc_tos(), key, &data);
445 if (!NT_STATUS_IS_OK(status)) {
446 DEBUG(3, ("Could not fetch share entry\n"));
449 if (data.dptr == NULL) {
452 lck = talloc(mem_ctx, struct share_mode_lock);
454 TALLOC_FREE(data.dptr);
457 lck->data = parse_share_modes(mem_ctx, data);
458 TALLOC_FREE(data.dptr);
459 if (lck->data == NULL) {
466 struct forall_state {
467 void (*fn)(const struct share_mode_entry *entry,
468 const char *sharepath,
474 static int traverse_fn(struct db_record *rec, void *_state)
476 struct forall_state *state = (struct forall_state *)_state;
481 enum ndr_err_code ndr_err;
482 struct share_mode_data *d;
484 key = dbwrap_record_get_key(rec);
485 value = dbwrap_record_get_value(rec);
487 /* Ensure this is a locking_key record. */
488 if (key.dsize != sizeof(struct file_id))
491 d = talloc(talloc_tos(), struct share_mode_data);
496 blob.data = value.dptr;
497 blob.length = value.dsize;
499 ndr_err = ndr_pull_struct_blob(
500 &blob, d, d, (ndr_pull_flags_fn_t)ndr_pull_share_mode_data);
501 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
502 DEBUG(1, ("ndr_pull_share_mode_lock failed\n"));
505 for (i=0; i<d->num_share_modes; i++) {
506 state->fn(&d->share_modes[i],
507 d->servicepath, d->base_name,
508 state->private_data);
515 /*******************************************************************
516 Call the specified function on each entry under management by the
518 ********************************************************************/
520 int share_mode_forall(void (*fn)(const struct share_mode_entry *, const char *,
521 const char *, void *),
524 struct forall_state state;
532 state.private_data = private_data;
534 status = dbwrap_traverse_read(lock_db, traverse_fn, (void *)&state,
537 if (!NT_STATUS_IS_OK(status)) {