2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2006
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 this is the change notify database. It implements mechanisms for
22 storing current change notify waiters in a tdb, and checking if a
23 given event matches any of the stored notify waiiters.
27 #include "system/filesys.h"
28 #include "../tdb/include/tdb.h"
29 #include "../lib/util/util_tdb.h"
30 #include "messaging/messaging.h"
32 #include "lib/messaging/irpc.h"
33 #include "librpc/gen_ndr/ndr_notify.h"
34 #include "../lib/util/dlinklist.h"
35 #include "ntvfs/common/ntvfs_common.h"
36 #include "ntvfs/sysdep/sys_notify.h"
37 #include "cluster/cluster.h"
38 #include "param/param.h"
40 struct notify_context {
42 struct server_id server;
43 struct messaging_context *messaging_ctx;
44 struct notify_list *list;
45 struct notify_array *array;
47 struct sys_notify_context *sys_notify_ctx;
48 struct smb_iconv_convenience *iconv_convenience;
53 struct notify_list *next, *prev;
55 void (*callback)(void *, const struct notify_event *);
56 void *sys_notify_handle;
60 #define NOTIFY_KEY "notify array"
62 #define NOTIFY_ENABLE "notify:enable"
63 #define NOTIFY_ENABLE_DEFAULT true
65 static NTSTATUS notify_remove_all(struct notify_context *notify);
66 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
67 uint32_t msg_type, struct server_id server_id, DATA_BLOB *data);
70 destroy the notify context
72 static int notify_destructor(struct notify_context *notify)
74 messaging_deregister(notify->messaging_ctx, MSG_PVFS_NOTIFY, notify);
75 notify_remove_all(notify);
80 Open up the notify.tdb database. You should close it down using
81 talloc_free(). We need the messaging_ctx to allow for notifications
84 struct notify_context *notify_init(TALLOC_CTX *mem_ctx, struct server_id server,
85 struct messaging_context *messaging_ctx,
86 struct loadparm_context *lp_ctx,
87 struct event_context *ev,
88 struct share_config *scfg)
90 struct notify_context *notify;
92 if (share_bool_option(scfg, NOTIFY_ENABLE, NOTIFY_ENABLE_DEFAULT) != true) {
100 notify = talloc(mem_ctx, struct notify_context);
101 if (notify == NULL) {
105 notify->w = cluster_tdb_tmp_open(notify, lp_ctx, "notify.tdb", TDB_SEQNUM);
106 if (notify->w == NULL) {
111 notify->server = server;
112 notify->messaging_ctx = messaging_ctx;
114 notify->array = NULL;
115 notify->iconv_convenience = lp_iconv_convenience(lp_ctx);
116 notify->seqnum = tdb_get_seqnum(notify->w->tdb);
118 talloc_set_destructor(notify, notify_destructor);
120 /* register with the messaging subsystem for the notify
122 messaging_register(notify->messaging_ctx, notify,
123 MSG_PVFS_NOTIFY, notify_handler);
125 notify->sys_notify_ctx = sys_notify_context_create(scfg, notify, ev);
134 static NTSTATUS notify_lock(struct notify_context *notify)
136 if (tdb_lock_bystring(notify->w->tdb, NOTIFY_KEY) != 0) {
137 return NT_STATUS_INTERNAL_DB_CORRUPTION;
145 static void notify_unlock(struct notify_context *notify)
147 tdb_unlock_bystring(notify->w->tdb, NOTIFY_KEY);
151 load the notify array
153 static NTSTATUS notify_load(struct notify_context *notify)
157 enum ndr_err_code ndr_err;
160 seqnum = tdb_get_seqnum(notify->w->tdb);
162 if (seqnum == notify->seqnum && notify->array != NULL) {
166 notify->seqnum = seqnum;
168 talloc_free(notify->array);
169 notify->array = talloc_zero(notify, struct notify_array);
170 NT_STATUS_HAVE_NO_MEMORY(notify->array);
172 dbuf = tdb_fetch_bystring(notify->w->tdb, NOTIFY_KEY);
173 if (dbuf.dptr == NULL) {
177 blob.data = dbuf.dptr;
178 blob.length = dbuf.dsize;
180 ndr_err = ndr_pull_struct_blob(&blob, notify->array, notify->iconv_convenience,
182 (ndr_pull_flags_fn_t)ndr_pull_notify_array);
184 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
185 return ndr_map_error2ntstatus(ndr_err);
192 compare notify entries for sorting
194 static int notify_compare(const void *p1, const void *p2)
196 const struct notify_entry *e1 = p1, *e2 = p2;
197 return strcmp(e1->path, e2->path);
201 save the notify array
203 static NTSTATUS notify_save(struct notify_context *notify)
207 enum ndr_err_code ndr_err;
211 /* if possible, remove some depth arrays */
212 while (notify->array->num_depths > 0 &&
213 notify->array->depth[notify->array->num_depths-1].num_entries == 0) {
214 notify->array->num_depths--;
217 /* we might just be able to delete the record */
218 if (notify->array->num_depths == 0) {
219 ret = tdb_delete_bystring(notify->w->tdb, NOTIFY_KEY);
221 return NT_STATUS_INTERNAL_DB_CORRUPTION;
226 tmp_ctx = talloc_new(notify);
227 NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);
229 ndr_err = ndr_push_struct_blob(&blob, tmp_ctx, notify->iconv_convenience, notify->array,
230 (ndr_push_flags_fn_t)ndr_push_notify_array);
231 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
232 talloc_free(tmp_ctx);
233 return ndr_map_error2ntstatus(ndr_err);
236 dbuf.dptr = blob.data;
237 dbuf.dsize = blob.length;
239 ret = tdb_store_bystring(notify->w->tdb, NOTIFY_KEY, dbuf, TDB_REPLACE);
240 talloc_free(tmp_ctx);
242 return NT_STATUS_INTERNAL_DB_CORRUPTION;
250 handle incoming notify messages
252 static void notify_handler(struct messaging_context *msg_ctx, void *private_data,
253 uint32_t msg_type, struct server_id server_id, DATA_BLOB *data)
255 struct notify_context *notify = talloc_get_type(private_data, struct notify_context);
256 enum ndr_err_code ndr_err;
257 struct notify_event ev;
258 TALLOC_CTX *tmp_ctx = talloc_new(notify);
259 struct notify_list *listel;
261 if (tmp_ctx == NULL) {
265 ndr_err = ndr_pull_struct_blob(data, tmp_ctx, notify->iconv_convenience, &ev,
266 (ndr_pull_flags_fn_t)ndr_pull_notify_event);
267 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
268 talloc_free(tmp_ctx);
272 for (listel=notify->list;listel;listel=listel->next) {
273 if (listel->private_data == ev.private_data) {
274 listel->callback(listel->private_data, &ev);
279 talloc_free(tmp_ctx);
283 callback from sys_notify telling us about changes from the OS
285 static void sys_notify_callback(struct sys_notify_context *ctx,
286 void *ptr, struct notify_event *ev)
288 struct notify_list *listel = talloc_get_type(ptr, struct notify_list);
289 ev->private_data = listel;
290 listel->callback(listel->private_data, ev);
294 add an entry to the notify array
296 static NTSTATUS notify_add_array(struct notify_context *notify, struct notify_entry *e,
297 void *private_data, int depth)
300 struct notify_depth *d;
301 struct notify_entry *ee;
303 /* possibly expand the depths array */
304 if (depth >= notify->array->num_depths) {
305 d = talloc_realloc(notify->array, notify->array->depth,
306 struct notify_depth, depth+1);
307 NT_STATUS_HAVE_NO_MEMORY(d);
308 for (i=notify->array->num_depths;i<=depth;i++) {
311 notify->array->depth = d;
312 notify->array->num_depths = depth+1;
314 d = ¬ify->array->depth[depth];
316 /* expand the entries array */
317 ee = talloc_realloc(notify->array->depth, d->entries, struct notify_entry,
319 NT_STATUS_HAVE_NO_MEMORY(ee);
322 d->entries[d->num_entries] = *e;
323 d->entries[d->num_entries].private_data = private_data;
324 d->entries[d->num_entries].server = notify->server;
325 d->entries[d->num_entries].path_len = strlen(e->path);
328 d->max_mask |= e->filter;
329 d->max_mask_subdir |= e->subdir_filter;
331 if (d->num_entries > 1) {
332 qsort(d->entries, d->num_entries, sizeof(d->entries[0]), notify_compare);
335 /* recalculate the maximum masks */
337 d->max_mask_subdir = 0;
339 for (i=0;i<d->num_entries;i++) {
340 d->max_mask |= d->entries[i].filter;
341 d->max_mask_subdir |= d->entries[i].subdir_filter;
344 return notify_save(notify);
348 add a notify watch. This is called when a notify is first setup on a open
351 NTSTATUS notify_add(struct notify_context *notify, struct notify_entry *e0,
352 void (*callback)(void *, const struct notify_event *),
355 struct notify_entry e = *e0;
357 char *tmp_path = NULL;
358 struct notify_list *listel;
362 /* see if change notify is enabled at all */
363 if (notify == NULL) {
364 return NT_STATUS_NOT_IMPLEMENTED;
367 status = notify_lock(notify);
368 NT_STATUS_NOT_OK_RETURN(status);
370 status = notify_load(notify);
371 if (!NT_STATUS_IS_OK(status)) {
375 /* cope with /. on the end of the path */
376 len = strlen(e.path);
377 if (len > 1 && e.path[len-1] == '.' && e.path[len-2] == '/') {
378 tmp_path = talloc_strndup(notify, e.path, len-2);
379 if (tmp_path == NULL) {
380 status = NT_STATUS_NO_MEMORY;
386 depth = count_chars(e.path, '/');
388 listel = talloc_zero(notify, struct notify_list);
389 if (listel == NULL) {
390 status = NT_STATUS_NO_MEMORY;
394 listel->private_data = private_data;
395 listel->callback = callback;
396 listel->depth = depth;
397 DLIST_ADD(notify->list, listel);
399 /* ignore failures from sys_notify */
400 if (notify->sys_notify_ctx != NULL) {
402 this call will modify e.filter and e.subdir_filter
403 to remove bits handled by the backend
405 status = sys_notify_watch(notify->sys_notify_ctx, &e,
406 sys_notify_callback, listel,
407 &listel->sys_notify_handle);
408 if (NT_STATUS_IS_OK(status)) {
409 talloc_steal(listel, listel->sys_notify_handle);
413 /* if the system notify handler couldn't handle some of the
414 filter bits, or couldn't handle a request for recursion
415 then we need to install it in the array used for the
416 intra-samba notify handling */
417 if (e.filter != 0 || e.subdir_filter != 0) {
418 status = notify_add_array(notify, &e, private_data, depth);
422 notify_unlock(notify);
423 talloc_free(tmp_path);
429 remove a notify watch. Called when the directory handle is closed
431 NTSTATUS notify_remove(struct notify_context *notify, void *private_data)
434 struct notify_list *listel;
436 struct notify_depth *d;
438 /* see if change notify is enabled at all */
439 if (notify == NULL) {
440 return NT_STATUS_NOT_IMPLEMENTED;
443 for (listel=notify->list;listel;listel=listel->next) {
444 if (listel->private_data == private_data) {
445 DLIST_REMOVE(notify->list, listel);
449 if (listel == NULL) {
450 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
453 depth = listel->depth;
457 status = notify_lock(notify);
458 NT_STATUS_NOT_OK_RETURN(status);
460 status = notify_load(notify);
461 if (!NT_STATUS_IS_OK(status)) {
462 notify_unlock(notify);
466 if (depth >= notify->array->num_depths) {
467 notify_unlock(notify);
468 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
471 /* we only have to search at the depth of this element */
472 d = ¬ify->array->depth[depth];
474 for (i=0;i<d->num_entries;i++) {
475 if (private_data == d->entries[i].private_data &&
476 cluster_id_equal(¬ify->server, &d->entries[i].server)) {
480 if (i == d->num_entries) {
481 notify_unlock(notify);
482 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
485 if (i < d->num_entries-1) {
486 memmove(&d->entries[i], &d->entries[i+1],
487 sizeof(d->entries[i])*(d->num_entries-(i+1)));
491 status = notify_save(notify);
493 notify_unlock(notify);
499 remove all notify watches for this messaging server
501 static NTSTATUS notify_remove_all(struct notify_context *notify)
504 int i, depth, del_count=0;
506 if (notify->list == NULL) {
510 status = notify_lock(notify);
511 NT_STATUS_NOT_OK_RETURN(status);
513 status = notify_load(notify);
514 if (!NT_STATUS_IS_OK(status)) {
515 notify_unlock(notify);
519 /* we have to search for all entries across all depths, looking for matches
521 for (depth=0;depth<notify->array->num_depths;depth++) {
522 struct notify_depth *d = ¬ify->array->depth[depth];
523 for (i=0;i<d->num_entries;i++) {
524 if (cluster_id_equal(¬ify->server, &d->entries[i].server)) {
525 if (i < d->num_entries-1) {
526 memmove(&d->entries[i], &d->entries[i+1],
527 sizeof(d->entries[i])*(d->num_entries-(i+1)));
537 status = notify_save(notify);
540 notify_unlock(notify);
547 send a notify message to another messaging server
549 static void notify_send(struct notify_context *notify, struct notify_entry *e,
550 const char *path, uint32_t action)
552 struct notify_event ev;
555 enum ndr_err_code ndr_err;
560 ev.private_data = e->private_data;
562 tmp_ctx = talloc_new(notify);
564 ndr_err = ndr_push_struct_blob(&data, tmp_ctx, notify->iconv_convenience, &ev, (ndr_push_flags_fn_t)ndr_push_notify_event);
565 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
566 talloc_free(tmp_ctx);
570 status = messaging_send(notify->messaging_ctx, e->server,
571 MSG_PVFS_NOTIFY, &data);
572 talloc_free(tmp_ctx);
577 trigger a notify message for anyone waiting on a matching event
579 This function is called a lot, and needs to be very fast. The unusual data structure
580 and traversal is designed to be fast in the average case, even for large numbers of
583 void notify_trigger(struct notify_context *notify,
584 uint32_t action, uint32_t filter, const char *path)
588 const char *p, *next_p;
590 /* see if change notify is enabled at all */
591 if (notify == NULL) {
595 status = notify_load(notify);
596 if (!NT_STATUS_IS_OK(status)) {
600 /* loop along the given path, working with each directory depth separately */
602 p && depth < notify->array->num_depths;
604 int p_len = p - path;
606 struct notify_depth *d = ¬ify->array->depth[depth];
607 next_p = strchr(p+1, '/');
609 /* see if there are any entries at this depth */
610 if (d->num_entries == 0) continue;
612 /* try to skip based on the maximum mask. If next_p is
613 NULL then we know it will be a 'this directory'
614 match, otherwise it must be a subdir match */
615 if (next_p != NULL) {
616 if (0 == (filter & d->max_mask_subdir)) {
620 if (0 == (filter & d->max_mask)) {
625 /* we know there is an entry here worth looking
626 for. Use a bisection search to find the first entry
627 with a matching path */
629 max_i = d->num_entries-1;
631 while (min_i < max_i) {
632 struct notify_entry *e;
636 cmp = strncmp(path, e->path, p_len);
638 if (p_len == e->path_len) {
643 } else if (cmp < 0) {
650 if (min_i != max_i) {
655 /* we now know that the entries start at min_i */
656 for (i=min_i;i<d->num_entries;i++) {
657 struct notify_entry *e = &d->entries[i];
658 if (p_len != e->path_len ||
659 strncmp(path, e->path, p_len) != 0) break;
660 if (next_p != NULL) {
661 if (0 == (filter & e->subdir_filter)) {
665 if (0 == (filter & e->filter)) {
669 notify_send(notify, e, path + e->path_len + 1, action);