1 /*
2 *
3 * D-Bus helper library
4 *
5 * Copyright (C) 2004-2009 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 name_exit_filter(DBusConnection *connection,
41 DBusMessage *message, void *user_data);
42
43 static guint listener_id = 0;
44 static GSList *name_listeners = NULL;
45
46 struct name_callback {
47 GDBusWatchFunction conn_func;
48 GDBusWatchFunction disc_func;
49 void *user_data;
50 guint id;
51 };
52
53 struct name_data {
54 DBusConnection *connection;
55 char *name;
56 GSList *callbacks;
57 GSList *processed;
58 gboolean lock;
59 };
60
name_data_find(DBusConnection * connection,const char * name)61 static struct name_data *name_data_find(DBusConnection *connection,
62 const char *name)
63 {
64 GSList *current;
65
66 for (current = name_listeners;
67 current != NULL; current = current->next) {
68 struct name_data *data = current->data;
69
70 if (connection != data->connection)
71 continue;
72
73 if (name == NULL || g_str_equal(name, data->name))
74 return data;
75 }
76
77 return NULL;
78 }
79
name_callback_find(GSList * callbacks,guint id)80 static struct name_callback *name_callback_find(GSList *callbacks, guint id)
81 {
82 GSList *current;
83
84 for (current = callbacks; current != NULL; current = current->next) {
85 struct name_callback *cb = current->data;
86 if (cb->id == id)
87 return cb;
88 }
89
90 return NULL;
91 }
92
name_data_call_and_free(struct name_data * data)93 static void name_data_call_and_free(struct name_data *data)
94 {
95 GSList *l;
96
97 for (l = data->callbacks; l != NULL; l = l->next) {
98 struct name_callback *cb = l->data;
99 if (cb->disc_func)
100 cb->disc_func(data->connection, cb->user_data);
101 g_free(cb);
102 }
103
104 g_slist_free(data->callbacks);
105 g_free(data->name);
106 g_free(data);
107 }
108
name_data_free(struct name_data * data)109 static void name_data_free(struct name_data *data)
110 {
111 GSList *l;
112
113 for (l = data->callbacks; l != NULL; l = l->next)
114 g_free(l->data);
115
116 g_slist_free(data->callbacks);
117 g_free(data->name);
118 g_free(data);
119 }
120
name_data_add(DBusConnection * connection,const char * name,GDBusWatchFunction connect,GDBusWatchFunction disconnect,void * user_data,guint id)121 static int name_data_add(DBusConnection *connection, const char *name,
122 GDBusWatchFunction connect,
123 GDBusWatchFunction disconnect,
124 void *user_data, guint id)
125 {
126 int first = 1;
127 struct name_data *data = NULL;
128 struct name_callback *cb = NULL;
129
130 cb = g_new(struct name_callback, 1);
131
132 cb->conn_func = connect;
133 cb->disc_func = disconnect;
134 cb->user_data = user_data;
135 cb->id = id;
136
137 data = name_data_find(connection, name);
138 if (data) {
139 first = 0;
140 goto done;
141 }
142
143 data = g_new0(struct name_data, 1);
144
145 data->connection = connection;
146 data->name = g_strdup(name);
147
148 name_listeners = g_slist_append(name_listeners, data);
149
150 done:
151 if (data->lock)
152 data->processed = g_slist_append(data->processed, cb);
153 else
154 data->callbacks = g_slist_append(data->callbacks, cb);
155
156 return first;
157 }
158
name_data_remove(DBusConnection * connection,const char * name,guint id)159 static void name_data_remove(DBusConnection *connection,
160 const char *name, guint id)
161 {
162 struct name_data *data;
163 struct name_callback *cb = NULL;
164
165 data = name_data_find(connection, name);
166 if (!data)
167 return;
168
169 cb = name_callback_find(data->callbacks, id);
170 if (cb) {
171 data->callbacks = g_slist_remove(data->callbacks, cb);
172 g_free(cb);
173 }
174
175 if (data->callbacks)
176 return;
177
178 name_listeners = g_slist_remove(name_listeners, data);
179 name_data_free(data);
180
181 /* Remove filter if there are no listeners left for the connection */
182 data = name_data_find(connection, NULL);
183 if (!data)
184 dbus_connection_remove_filter(connection,
185 name_exit_filter,
186 NULL);
187 }
188
add_match(DBusConnection * connection,const char * name)189 static gboolean add_match(DBusConnection *connection, const char *name)
190 {
191 DBusError err;
192 char match_string[128];
193
194 snprintf(match_string, sizeof(match_string),
195 "interface=%s,member=NameOwnerChanged,arg0=%s",
196 DBUS_INTERFACE_DBUS, name);
197
198 dbus_error_init(&err);
199
200 dbus_bus_add_match(connection, match_string, &err);
201
202 if (dbus_error_is_set(&err)) {
203 error("Adding match rule \"%s\" failed: %s", match_string,
204 err.message);
205 dbus_error_free(&err);
206 return FALSE;
207 }
208
209 return TRUE;
210 }
211
remove_match(DBusConnection * connection,const char * name)212 static gboolean remove_match(DBusConnection *connection, const char *name)
213 {
214 DBusError err;
215 char match_string[128];
216
217 snprintf(match_string, sizeof(match_string),
218 "interface=%s,member=NameOwnerChanged,arg0=%s",
219 DBUS_INTERFACE_DBUS, name);
220
221 dbus_error_init(&err);
222
223 dbus_bus_remove_match(connection, match_string, &err);
224
225 if (dbus_error_is_set(&err)) {
226 error("Removing owner match rule for %s failed: %s",
227 name, err.message);
228 dbus_error_free(&err);
229 return FALSE;
230 }
231
232 return TRUE;
233 }
234
name_exit_filter(DBusConnection * connection,DBusMessage * message,void * user_data)235 static DBusHandlerResult name_exit_filter(DBusConnection *connection,
236 DBusMessage *message, void *user_data)
237 {
238 struct name_data *data;
239 struct name_callback *cb;
240 char *name, *old, *new;
241
242 if (!dbus_message_is_signal(message, DBUS_INTERFACE_DBUS,
243 "NameOwnerChanged"))
244 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
245
246 if (!dbus_message_get_args(message, NULL,
247 DBUS_TYPE_STRING, &name,
248 DBUS_TYPE_STRING, &old,
249 DBUS_TYPE_STRING, &new,
250 DBUS_TYPE_INVALID)) {
251 error("Invalid arguments for NameOwnerChanged signal");
252 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
253 }
254
255 data = name_data_find(connection, name);
256 if (!data) {
257 error("Got NameOwnerChanged signal for %s which has no listeners", name);
258 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
259 }
260
261 data->lock = TRUE;
262
263 while (data->callbacks) {
264 cb = data->callbacks->data;
265
266 if (*new == '\0') {
267 if (cb->disc_func)
268 cb->disc_func(connection, cb->user_data);
269 } else {
270 if (cb->conn_func)
271 cb->conn_func(connection, cb->user_data);
272 }
273
274 /* Check if the watch was removed/freed by the callback
275 * function */
276 if (!g_slist_find(data->callbacks, cb))
277 continue;
278
279 data->callbacks = g_slist_remove(data->callbacks, cb);
280
281 if (!cb->conn_func || !cb->disc_func) {
282 g_free(cb);
283 continue;
284 }
285
286 data->processed = g_slist_append(data->processed, cb);
287 }
288
289 data->callbacks = data->processed;
290 data->processed = NULL;
291 data->lock = FALSE;
292
293 if (data->callbacks)
294 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
295
296 name_listeners = g_slist_remove(name_listeners, data);
297 name_data_free(data);
298
299 /* Remove filter if there no listener left for the connection */
300 data = name_data_find(connection, NULL);
301 if (!data)
302 dbus_connection_remove_filter(connection, name_exit_filter,
303 NULL);
304
305 remove_match(connection, name);
306
307 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
308 }
309
g_dbus_add_service_watch(DBusConnection * connection,const char * name,GDBusWatchFunction connect,GDBusWatchFunction disconnect,void * user_data,GDBusDestroyFunction destroy)310 guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
311 GDBusWatchFunction connect,
312 GDBusWatchFunction disconnect,
313 void *user_data, GDBusDestroyFunction destroy)
314 {
315 int first;
316
317 if (!name_data_find(connection, NULL)) {
318 if (!dbus_connection_add_filter(connection,
319 name_exit_filter, NULL, NULL)) {
320 error("dbus_connection_add_filter() failed");
321 return 0;
322 }
323 }
324
325 listener_id++;
326 first = name_data_add(connection, name, connect, disconnect,
327 user_data, listener_id);
328 /* The filter is already added if this is not the first callback
329 * registration for the name */
330 if (!first)
331 return listener_id;
332
333 if (name) {
334 debug("name_listener_add(%s)", name);
335
336 if (!add_match(connection, name)) {
337 name_data_remove(connection, name, listener_id);
338 return 0;
339 }
340 }
341
342 return listener_id;
343 }
344
g_dbus_add_disconnect_watch(DBusConnection * connection,const char * name,GDBusWatchFunction func,void * user_data,GDBusDestroyFunction destroy)345 guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
346 GDBusWatchFunction func,
347 void *user_data, GDBusDestroyFunction destroy)
348 {
349 return g_dbus_add_service_watch(connection, name, NULL, func,
350 user_data, destroy);
351 }
352
g_dbus_add_signal_watch(DBusConnection * connection,const char * rule,GDBusSignalFunction function,void * user_data,GDBusDestroyFunction destroy)353 guint g_dbus_add_signal_watch(DBusConnection *connection,
354 const char *rule, GDBusSignalFunction function,
355 void *user_data, GDBusDestroyFunction destroy)
356 {
357 return 0;
358 }
359
g_dbus_remove_watch(DBusConnection * connection,guint id)360 gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
361 {
362 struct name_data *data;
363 struct name_callback *cb;
364 GSList *ldata, *lcb;
365
366 if (id == 0)
367 return FALSE;
368
369 for (ldata = name_listeners; ldata; ldata = ldata->next) {
370 data = ldata->data;
371 for (lcb = data->callbacks; lcb; lcb = lcb->next) {
372 cb = lcb->data;
373 if (cb->id == id)
374 goto remove;
375 }
376 for (lcb = data->processed; lcb; lcb = lcb->next) {
377 cb = lcb->data;
378 if (cb->id == id)
379 goto remove;
380 }
381 }
382
383 return FALSE;
384
385 remove:
386 data->callbacks = g_slist_remove(data->callbacks, cb);
387 data->processed = g_slist_remove(data->processed, cb);
388 g_free(cb);
389
390 /* Don't remove the filter if other callbacks exist or data is lock
391 * processing callbacks */
392 if (data->callbacks || data->lock)
393 return TRUE;
394
395 if (data->name) {
396 if (!remove_match(data->connection, data->name))
397 return FALSE;
398 }
399
400 name_listeners = g_slist_remove(name_listeners, data);
401 name_data_free(data);
402
403 /* Remove filter if there are no listeners left for the connection */
404 data = name_data_find(connection, NULL);
405 if (!data)
406 dbus_connection_remove_filter(connection, name_exit_filter,
407 NULL);
408
409 return TRUE;
410 }
411
g_dbus_remove_all_watches(DBusConnection * connection)412 void g_dbus_remove_all_watches(DBusConnection *connection)
413 {
414 struct name_data *data;
415
416 while ((data = name_data_find(connection, NULL))) {
417 name_listeners = g_slist_remove(name_listeners, data);
418 name_data_call_and_free(data);
419 }
420
421 dbus_connection_remove_filter(connection, name_exit_filter, NULL);
422 }
423