9e4f994a396b1156a52b1aab80fd50d0f8b1d92a
[platform/upstream/connman.git] / gdbus / watch.c
1 /*
2  *
3  *  D-Bus helper library
4  *
5  *  Copyright (C) 2004-2011  Marcel Holtmann <marcel@holtmann.org>
6  *
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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
21  *
22  */
23
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27
28 #include <stdio.h>
29 #include <string.h>
30
31 #include <glib.h>
32 #include <dbus/dbus.h>
33
34 #include "gdbus.h"
35
36 #define info(fmt...)
37 #define error(fmt...)
38 #define debug(fmt...)
39
40 static DBusHandlerResult message_filter(DBusConnection *connection,
41                                         DBusMessage *message, void *user_data);
42
43 static guint listener_id = 0;
44 static GSList *listeners = NULL;
45
46 struct service_data {
47         DBusConnection *conn;
48         DBusPendingCall *call;
49         char *name;
50         const char *owner;
51         guint id;
52         struct filter_callback *callback;
53 };
54
55 struct filter_callback {
56         GDBusWatchFunction conn_func;
57         GDBusWatchFunction disc_func;
58         GDBusSignalFunction signal_func;
59         GDBusDestroyFunction destroy_func;
60         struct service_data *data;
61         void *user_data;
62         guint id;
63 };
64
65 struct filter_data {
66         DBusConnection *connection;
67         DBusHandleMessageFunction handle_func;
68         char *name;
69         char *owner;
70         char *path;
71         char *interface;
72         char *member;
73         char *argument;
74         GSList *callbacks;
75         GSList *processed;
76         guint name_watch;
77         gboolean lock;
78         gboolean registered;
79 };
80
81 static struct filter_data *filter_data_find_match(DBusConnection *connection,
82                                                         const char *name,
83                                                         const char *owner,
84                                                         const char *path,
85                                                         const char *interface,
86                                                         const char *member,
87                                                         const char *argument)
88 {
89         GSList *current;
90
91         for (current = listeners;
92                         current != NULL; current = current->next) {
93                 struct filter_data *data = current->data;
94
95                 if (connection != data->connection)
96                         continue;
97
98                 if (g_strcmp0(name, data->name) != 0)
99                         continue;
100
101                 if (g_strcmp0(owner, data->owner) != 0)
102                         continue;
103
104                 if (g_strcmp0(path, data->path) != 0)
105                         continue;
106
107                 if (g_strcmp0(interface, data->interface) != 0)
108                         continue;
109
110                 if (g_strcmp0(member, data->member) != 0)
111                         continue;
112
113                 if (g_strcmp0(argument, data->argument) != 0)
114                         continue;
115
116                 return data;
117         }
118
119         return NULL;
120 }
121
122 static struct filter_data *filter_data_find(DBusConnection *connection)
123 {
124         GSList *current;
125
126         for (current = listeners;
127                         current != NULL; current = current->next) {
128                 struct filter_data *data = current->data;
129
130                 if (connection != data->connection)
131                         continue;
132
133                 return data;
134         }
135
136         return NULL;
137 }
138
139 static void format_rule(struct filter_data *data, char *rule, size_t size)
140 {
141         const char *sender;
142         int offset;
143
144         offset = snprintf(rule, size, "type='signal'");
145         sender = data->name ? : data->owner;
146
147         if (sender)
148                 offset += snprintf(rule + offset, size - offset,
149                                 ",sender='%s'", sender);
150         if (data->path)
151                 offset += snprintf(rule + offset, size - offset,
152                                 ",path='%s'", data->path);
153         if (data->interface)
154                 offset += snprintf(rule + offset, size - offset,
155                                 ",interface='%s'", data->interface);
156         if (data->member)
157                 offset += snprintf(rule + offset, size - offset,
158                                 ",member='%s'", data->member);
159         if (data->argument)
160                 snprintf(rule + offset, size - offset,
161                                 ",arg0='%s'", data->argument);
162 }
163
164 static gboolean add_match(struct filter_data *data,
165                                 DBusHandleMessageFunction filter)
166 {
167         DBusError err;
168         char rule[DBUS_MAXIMUM_MATCH_RULE_LENGTH];
169
170         format_rule(data, rule, sizeof(rule));
171         dbus_error_init(&err);
172
173         dbus_bus_add_match(data->connection, rule, &err);
174         if (dbus_error_is_set(&err)) {
175                 error("Adding match rule \"%s\" failed: %s", rule,
176                                 err.message);
177                 dbus_error_free(&err);
178                 return FALSE;
179         }
180
181         data->handle_func = filter;
182         data->registered = TRUE;
183
184         return TRUE;
185 }
186
187 static gboolean remove_match(struct filter_data *data)
188 {
189         DBusError err;
190         char rule[DBUS_MAXIMUM_MATCH_RULE_LENGTH];
191
192         format_rule(data, rule, sizeof(rule));
193
194         dbus_error_init(&err);
195
196         dbus_bus_remove_match(data->connection, rule, &err);
197         if (dbus_error_is_set(&err)) {
198                 error("Removing owner match rule for %s failed: %s",
199                                 rule, err.message);
200                 dbus_error_free(&err);
201                 return FALSE;
202         }
203
204         return TRUE;
205 }
206
207 static struct filter_data *filter_data_get(DBusConnection *connection,
208                                         DBusHandleMessageFunction filter,
209                                         const char *sender,
210                                         const char *path,
211                                         const char *interface,
212                                         const char *member,
213                                         const char *argument)
214 {
215         struct filter_data *data;
216         const char *name = NULL, *owner = NULL;
217
218         if (filter_data_find(connection) == NULL) {
219                 if (!dbus_connection_add_filter(connection,
220                                         message_filter, NULL, NULL)) {
221                         error("dbus_connection_add_filter() failed");
222                         return NULL;
223                 }
224         }
225
226         if (sender == NULL)
227                 goto proceed;
228
229         if (sender[0] == ':')
230                 owner = sender;
231         else
232                 name = sender;
233
234 proceed:
235         data = filter_data_find_match(connection, name, owner, path,
236                                                 interface, member, argument);
237         if (data)
238                 return data;
239
240         data = g_new0(struct filter_data, 1);
241
242         data->connection = dbus_connection_ref(connection);
243         data->name = g_strdup(name);
244         data->owner = g_strdup(owner);
245         data->path = g_strdup(path);
246         data->interface = g_strdup(interface);
247         data->member = g_strdup(member);
248         data->argument = g_strdup(argument);
249
250         if (!add_match(data, filter)) {
251                 g_free(data);
252                 return NULL;
253         }
254
255         listeners = g_slist_append(listeners, data);
256
257         return data;
258 }
259
260 static struct filter_callback *filter_data_find_callback(
261                                                 struct filter_data *data,
262                                                 guint id)
263 {
264         GSList *l;
265
266         for (l = data->callbacks; l; l = l->next) {
267                 struct filter_callback *cb = l->data;
268                 if (cb->id == id)
269                         return cb;
270         }
271         for (l = data->processed; l; l = l->next) {
272                 struct filter_callback *cb = l->data;
273                 if (cb->id == id)
274                         return cb;
275         }
276
277         return NULL;
278 }
279
280 static void filter_data_free(struct filter_data *data)
281 {
282         GSList *l;
283
284         for (l = data->callbacks; l != NULL; l = l->next)
285                 g_free(l->data);
286
287         g_slist_free(data->callbacks);
288         g_dbus_remove_watch(data->connection, data->name_watch);
289         g_free(data->name);
290         g_free(data->owner);
291         g_free(data->path);
292         g_free(data->interface);
293         g_free(data->member);
294         g_free(data->argument);
295         dbus_connection_unref(data->connection);
296         g_free(data);
297 }
298
299 static void filter_data_call_and_free(struct filter_data *data)
300 {
301         GSList *l;
302
303         for (l = data->callbacks; l != NULL; l = l->next) {
304                 struct filter_callback *cb = l->data;
305                 if (cb->disc_func)
306                         cb->disc_func(data->connection, cb->user_data);
307                 if (cb->destroy_func)
308                         cb->destroy_func(cb->user_data);
309                 g_free(cb);
310         }
311
312         filter_data_free(data);
313 }
314
315 static struct filter_callback *filter_data_add_callback(
316                                                 struct filter_data *data,
317                                                 GDBusWatchFunction connect,
318                                                 GDBusWatchFunction disconnect,
319                                                 GDBusSignalFunction signal,
320                                                 GDBusDestroyFunction destroy,
321                                                 void *user_data)
322 {
323         struct filter_callback *cb = NULL;
324
325         cb = g_new0(struct filter_callback, 1);
326
327         cb->conn_func = connect;
328         cb->disc_func = disconnect;
329         cb->signal_func = signal;
330         cb->destroy_func = destroy;
331         cb->user_data = user_data;
332         cb->id = ++listener_id;
333
334         if (data->lock)
335                 data->processed = g_slist_append(data->processed, cb);
336         else
337                 data->callbacks = g_slist_append(data->callbacks, cb);
338
339         return cb;
340 }
341
342 static void service_data_free(struct service_data *data)
343 {
344         struct filter_callback *callback = data->callback;
345
346         dbus_connection_unref(data->conn);
347
348         if (data->call)
349                 dbus_pending_call_unref(data->call);
350
351         if (data->id)
352                 g_source_remove(data->id);
353
354         g_free(data->name);
355         g_free(data);
356
357         callback->data = NULL;
358 }
359
360 static gboolean filter_data_remove_callback(struct filter_data *data,
361                                                 struct filter_callback *cb)
362 {
363         DBusConnection *connection;
364
365         data->callbacks = g_slist_remove(data->callbacks, cb);
366         data->processed = g_slist_remove(data->processed, cb);
367
368         /* Cancel pending operations */
369         if (cb->data) {
370                 if (cb->data->call)
371                         dbus_pending_call_cancel(cb->data->call);
372                 service_data_free(cb->data);
373         }
374
375         if (cb->destroy_func)
376                 cb->destroy_func(cb->user_data);
377
378         g_free(cb);
379
380         /* Don't remove the filter if other callbacks exist or data is lock
381          * processing callbacks */
382         if (data->callbacks || data->lock)
383                 return TRUE;
384
385         if (data->registered && !remove_match(data))
386                 return FALSE;
387
388         connection = dbus_connection_ref(data->connection);
389         listeners = g_slist_remove(listeners, data);
390
391         /* Remove filter if there are no listeners left for the connection */
392         if (filter_data_find(connection) == NULL)
393                 dbus_connection_remove_filter(connection, message_filter,
394                                                 NULL);
395
396         filter_data_free(data);
397         dbus_connection_unref(connection);
398
399         return TRUE;
400 }
401
402 static DBusHandlerResult signal_filter(DBusConnection *connection,
403                                         DBusMessage *message, void *user_data)
404 {
405         struct filter_data *data = user_data;
406         struct filter_callback *cb;
407
408         while (data->callbacks) {
409                 cb = data->callbacks->data;
410
411                 if (cb->signal_func && !cb->signal_func(connection, message,
412                                                         cb->user_data)) {
413                         filter_data_remove_callback(data, cb);
414                         continue;
415                 }
416
417                 /* Check if the watch was removed/freed by the callback
418                  * function */
419                 if (!g_slist_find(data->callbacks, cb))
420                         continue;
421
422                 data->callbacks = g_slist_remove(data->callbacks, cb);
423                 data->processed = g_slist_append(data->processed, cb);
424         }
425
426         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
427 }
428
429 static void update_name_cache(const char *name, const char *owner)
430 {
431         GSList *l;
432
433         for (l = listeners; l != NULL; l = l->next) {
434                 struct filter_data *data = l->data;
435
436                 if (g_strcmp0(data->name, name) != 0)
437                         continue;
438
439                 g_free(data->owner);
440                 data->owner = g_strdup(owner);
441         }
442 }
443
444 static const char *check_name_cache(const char *name)
445 {
446         GSList *l;
447
448         for (l = listeners; l != NULL; l = l->next) {
449                 struct filter_data *data = l->data;
450
451                 if (g_strcmp0(data->name, name) != 0)
452                         continue;
453
454                 return data->owner;
455         }
456
457         return NULL;
458 }
459
460 static DBusHandlerResult service_filter(DBusConnection *connection,
461                                         DBusMessage *message, void *user_data)
462 {
463         struct filter_data *data = user_data;
464         struct filter_callback *cb;
465         char *name, *old, *new;
466
467         if (!dbus_message_get_args(message, NULL,
468                                 DBUS_TYPE_STRING, &name,
469                                 DBUS_TYPE_STRING, &old,
470                                 DBUS_TYPE_STRING, &new,
471                                 DBUS_TYPE_INVALID)) {
472                 error("Invalid arguments for NameOwnerChanged signal");
473                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
474         }
475
476         update_name_cache(name, new);
477
478         while (data->callbacks) {
479                 cb = data->callbacks->data;
480
481                 if (*new == '\0') {
482                         if (cb->disc_func)
483                                 cb->disc_func(connection, cb->user_data);
484                 } else {
485                         if (cb->conn_func)
486                                 cb->conn_func(connection, cb->user_data);
487                 }
488
489                 /* Check if the watch was removed/freed by the callback
490                  * function */
491                 if (!g_slist_find(data->callbacks, cb))
492                         continue;
493
494                 /* Only auto remove if it is a bus name watch */
495                 if (data->argument[0] == ':' &&
496                                 (cb->conn_func == NULL || cb->disc_func == NULL)) {
497                         filter_data_remove_callback(data, cb);
498                         continue;
499                 }
500
501                 data->callbacks = g_slist_remove(data->callbacks, cb);
502                 data->processed = g_slist_append(data->processed, cb);
503         }
504
505         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
506 }
507
508
509 static DBusHandlerResult message_filter(DBusConnection *connection,
510                                         DBusMessage *message, void *user_data)
511 {
512         struct filter_data *data;
513         const char *sender, *path, *iface, *member, *arg = NULL;
514         GSList *current, *delete_listener = NULL;
515
516         /* Only filter signals */
517         if (dbus_message_get_type(message) != DBUS_MESSAGE_TYPE_SIGNAL)
518                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
519
520         sender = dbus_message_get_sender(message);
521         path = dbus_message_get_path(message);
522         iface = dbus_message_get_interface(message);
523         member = dbus_message_get_member(message);
524         dbus_message_get_args(message, NULL, DBUS_TYPE_STRING, &arg, DBUS_TYPE_INVALID);
525
526         /* Sender is always the owner */
527
528         for (current = listeners; current != NULL; current = current->next) {
529                 data = current->data;
530
531                 if (connection != data->connection)
532                         continue;
533
534                 if (data->owner && g_str_equal(sender, data->owner) == FALSE)
535                         continue;
536
537                 if (data->path && g_str_equal(path, data->path) == FALSE)
538                         continue;
539
540                 if (data->interface && g_str_equal(iface,
541                                                 data->interface) == FALSE)
542                         continue;
543
544                 if (data->member && g_str_equal(member, data->member) == FALSE)
545                         continue;
546
547                 if (data->argument && g_str_equal(arg,
548                                                 data->argument) == FALSE)
549                         continue;
550
551                 if (data->handle_func) {
552                         data->lock = TRUE;
553
554                         data->handle_func(connection, message, data);
555
556                         data->callbacks = data->processed;
557                         data->processed = NULL;
558                         data->lock = FALSE;
559                 }
560
561                 if (!data->callbacks)
562                         delete_listener = g_slist_prepend(delete_listener,
563                                                                 current);
564         }
565
566         for (current = delete_listener; current != NULL;
567                                         current = delete_listener->next) {
568                 GSList *l = current->data;
569
570                 data = l->data;
571
572                 /* Has any other callback added callbacks back to this data? */
573                 if (data->callbacks != NULL)
574                         continue;
575
576                 remove_match(data);
577                 listeners = g_slist_delete_link(listeners, l);
578
579                 filter_data_free(data);
580         }
581
582         g_slist_free(delete_listener);
583
584         /* Remove filter if there are no listeners left for the connection */
585         if (filter_data_find(connection) == NULL)
586                 dbus_connection_remove_filter(connection, message_filter,
587                                                 NULL);
588
589         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
590 }
591
592 static gboolean update_service(void *user_data)
593 {
594         struct service_data *data = user_data;
595         struct filter_callback *cb = data->callback;
596
597         update_name_cache(data->name, data->owner);
598         if (cb->conn_func)
599                 cb->conn_func(data->conn, cb->user_data);
600
601         service_data_free(data);
602
603         return FALSE;
604 }
605
606 static void service_reply(DBusPendingCall *call, void *user_data)
607 {
608         struct service_data *data = user_data;
609         DBusMessage *reply;
610         DBusError err;
611
612         reply = dbus_pending_call_steal_reply(call);
613         if (reply == NULL)
614                 return;
615
616         dbus_error_init(&err);
617
618         if (dbus_set_error_from_message(&err, reply))
619                 goto fail;
620
621         if (dbus_message_get_args(reply, &err,
622                                         DBUS_TYPE_STRING, &data->owner,
623                                                 DBUS_TYPE_INVALID) == FALSE)
624                 goto fail;
625
626         update_service(data);
627
628         goto done;
629
630 fail:
631         error("%s", err.message);
632         dbus_error_free(&err);
633         service_data_free(data);
634 done:
635         dbus_message_unref(reply);
636 }
637
638 static void check_service(DBusConnection *connection,
639                                         const char *name,
640                                         struct filter_callback *callback)
641 {
642         DBusMessage *message;
643         struct service_data *data;
644
645         data = g_try_malloc0(sizeof(*data));
646         if (data == NULL) {
647                 error("Can't allocate data structure");
648                 return;
649         }
650
651         data->conn = dbus_connection_ref(connection);
652         data->name = g_strdup(name);
653         data->callback = callback;
654         callback->data = data;
655
656         data->owner = check_name_cache(name);
657         if (data->owner != NULL) {
658                 data->id = g_idle_add(update_service, data);
659                 return;
660         }
661
662         message = dbus_message_new_method_call(DBUS_SERVICE_DBUS,
663                         DBUS_PATH_DBUS, DBUS_INTERFACE_DBUS, "GetNameOwner");
664         if (message == NULL) {
665                 error("Can't allocate new message");
666                 g_free(data);
667                 return;
668         }
669
670         dbus_message_append_args(message, DBUS_TYPE_STRING, &name,
671                                                         DBUS_TYPE_INVALID);
672
673         if (dbus_connection_send_with_reply(connection, message,
674                                                         &data->call, -1) == FALSE) {
675                 error("Failed to execute method call");
676                 g_free(data);
677                 goto done;
678         }
679
680         if (data->call == NULL) {
681                 error("D-Bus connection not available");
682                 g_free(data);
683                 goto done;
684         }
685
686         dbus_pending_call_set_notify(data->call, service_reply, data, NULL);
687
688 done:
689         dbus_message_unref(message);
690 }
691
692 guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
693                                 GDBusWatchFunction connect,
694                                 GDBusWatchFunction disconnect,
695                                 void *user_data, GDBusDestroyFunction destroy)
696 {
697         struct filter_data *data;
698         struct filter_callback *cb;
699
700         if (name == NULL)
701                 return 0;
702
703         data = filter_data_get(connection, service_filter, NULL, NULL,
704                                 DBUS_INTERFACE_DBUS, "NameOwnerChanged",
705                                 name);
706         if (data == NULL)
707                 return 0;
708
709         cb = filter_data_add_callback(data, connect, disconnect, NULL, destroy,
710                                         user_data);
711         if (cb == NULL)
712                 return 0;
713
714         if (connect)
715                 check_service(connection, name, cb);
716
717         return cb->id;
718 }
719
720 guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
721                                 GDBusWatchFunction func,
722                                 void *user_data, GDBusDestroyFunction destroy)
723 {
724         return g_dbus_add_service_watch(connection, name, NULL, func,
725                                                         user_data, destroy);
726 }
727
728 guint g_dbus_add_signal_watch(DBusConnection *connection,
729                                 const char *sender, const char *path,
730                                 const char *interface, const char *member,
731                                 GDBusSignalFunction function, void *user_data,
732                                 GDBusDestroyFunction destroy)
733 {
734         struct filter_data *data;
735         struct filter_callback *cb;
736
737         data = filter_data_get(connection, signal_filter, sender, path,
738                                 interface, member, NULL);
739         if (data == NULL)
740                 return 0;
741
742         cb = filter_data_add_callback(data, NULL, NULL, function, destroy,
743                                         user_data);
744         if (cb == NULL)
745                 return 0;
746
747         if (data->name != NULL && data->name_watch == 0)
748                 data->name_watch = g_dbus_add_service_watch(connection,
749                                                         data->name, NULL,
750                                                         NULL, NULL, NULL);
751
752         return cb->id;
753 }
754
755 guint g_dbus_add_properties_watch(DBusConnection *connection,
756                                 const char *sender, const char *path,
757                                 const char *interface,
758                                 GDBusSignalFunction function, void *user_data,
759                                 GDBusDestroyFunction destroy)
760 {
761         struct filter_data *data;
762         struct filter_callback *cb;
763
764         data = filter_data_get(connection, signal_filter, sender, path,
765                                 DBUS_INTERFACE_PROPERTIES, "PropertiesChanged",
766                                 interface);
767         if (data == NULL)
768                 return 0;
769
770         cb = filter_data_add_callback(data, NULL, NULL, function, destroy,
771                                         user_data);
772         if (cb == NULL)
773                 return 0;
774
775         if (data->name != NULL && data->name_watch == 0)
776                 data->name_watch = g_dbus_add_service_watch(connection,
777                                                         data->name, NULL,
778                                                         NULL, NULL, NULL);
779
780         return cb->id;
781 }
782
783 gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
784 {
785         struct filter_data *data;
786         struct filter_callback *cb;
787         GSList *ldata;
788
789         if (id == 0)
790                 return FALSE;
791
792         for (ldata = listeners; ldata; ldata = ldata->next) {
793                 data = ldata->data;
794
795                 cb = filter_data_find_callback(data, id);
796                 if (cb) {
797                         filter_data_remove_callback(data, cb);
798                         return TRUE;
799                 }
800         }
801
802         return FALSE;
803 }
804
805 void g_dbus_remove_all_watches(DBusConnection *connection)
806 {
807         struct filter_data *data;
808
809         while ((data = filter_data_find(connection))) {
810                 listeners = g_slist_remove(listeners, data);
811                 filter_data_call_and_free(data);
812         }
813
814         dbus_connection_remove_filter(connection, message_filter, NULL);
815 }