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 #if defined TIZEN_EXT
 140 #define SENDER_PREFIX ",sender='%s'"
 141 #define PATH_PREFIX ",path='%s'"
 142 #define IFACE_PREFIX ",interface='%s'"
 143 #define MEMBER_PREFIX ",member='%s'"
 144 #define ARG0_PREFIX ",arg0='%s'"
 145
 146 static gboolean check_rule_length(int remains, const char *prefix, const char *data)
 147 {
 148         if (!prefix || !data)
 149                 return FALSE;
 150
 151         return strlen(prefix) - 2 + strlen(data) < remains;
 152 }
 153
 154 static void format_rule(struct filter_data *data, char *rule, size_t size)
 155 {
 156         const char *sender;
 157         int offset;
 158
 159         offset = snprintf(rule, size, "type='signal'");
 160         sender = data->name ? : data->owner;
 161
 162         if (sender &&
 163                         check_rule_length(size - offset, SENDER_PREFIX, sender))
 164                 offset += snprintf(rule + offset, size - offset,
 165                                 SENDER_PREFIX, sender);
 166         if (data->path &&
 167                         check_rule_length(size - offset, PATH_PREFIX, data->path))
 168                 offset += snprintf(rule + offset, size - offset,
 169                                 PATH_PREFIX, data->path);
 170         if (data->interface &&
 171                         check_rule_length(size - offset, IFACE_PREFIX, data->interface))
 172                 offset += snprintf(rule + offset, size - offset,
 173                                 IFACE_PREFIX, data->interface);
 174         if (data->member &&
 175                         check_rule_length(size - offset, MEMBER_PREFIX, data->member))
 176                 offset += snprintf(rule + offset, size - offset,
 177                                 MEMBER_PREFIX, data->member);
 178         if (data->argument &&
 179                         check_rule_length(size - offset, ARG0_PREFIX, data->argument))
 180                 snprintf(rule + offset, size - offset,
 181                                 ARG0_PREFIX, data->argument);
 182 }
 183 #else
 184 static void format_rule(struct filter_data *data, char *rule, size_t size)
 185 {
 186         const char *sender;
 187         int offset;
 188
 189         offset = snprintf(rule, size, "type='signal'");
 190         sender = data->name ? : data->owner;
 191
 192         if (sender)
 193                 offset += snprintf(rule + offset, size - offset,
 194                                 ",sender='%s'", sender);
 195         if (data->path)
 196                 offset += snprintf(rule + offset, size - offset,
 197                                 ",path='%s'", data->path);
 198         if (data->interface)
 199                 offset += snprintf(rule + offset, size - offset,
 200                                 ",interface='%s'", data->interface);
 201         if (data->member)
 202                 offset += snprintf(rule + offset, size - offset,
 203                                 ",member='%s'", data->member);
 204         if (data->argument)
 205                 snprintf(rule + offset, size - offset,
 206                                 ",arg0='%s'", data->argument);
 207 }
 208 #endif
 209
 210 static gboolean add_match(struct filter_data *data,
 211                                 DBusHandleMessageFunction filter)
 212 {
 213         DBusError err;
 214         char rule[DBUS_MAXIMUM_MATCH_RULE_LENGTH];
 215
 216         format_rule(data, rule, sizeof(rule));
 217         dbus_error_init(&err);
 218
 219         dbus_bus_add_match(data->connection, rule, &err);
 220         if (dbus_error_is_set(&err)) {
 221                 error("Adding match rule \"%s\" failed: %s", rule,
 222                                 err.message);
 223                 dbus_error_free(&err);
 224                 return FALSE;
 225         }
 226
 227         data->handle_func = filter;
 228         data->registered = TRUE;
 229
 230         return TRUE;
 231 }
 232
 233 static gboolean remove_match(struct filter_data *data)
 234 {
 235         DBusError err;
 236         char rule[DBUS_MAXIMUM_MATCH_RULE_LENGTH];
 237
 238         format_rule(data, rule, sizeof(rule));
 239
 240         dbus_error_init(&err);
 241
 242         dbus_bus_remove_match(data->connection, rule, &err);
 243         if (dbus_error_is_set(&err)) {
 244                 error("Removing owner match rule for %s failed: %s",
 245                                 rule, err.message);
 246                 dbus_error_free(&err);
 247                 return FALSE;
 248         }
 249
 250         return TRUE;
 251 }
 252
 253 static void filter_data_free(struct filter_data *data)
 254 {
 255         GSList *l;
 256
 257         /* Remove filter if there are no listeners left for the connection */
 258         if (filter_data_find(data->connection) == NULL)
 259                 dbus_connection_remove_filter(data->connection, message_filter,
 260                                                                         NULL);
 261
 262         for (l = data->callbacks; l != NULL; l = l->next)
 263                 g_free(l->data);
 264
 265         g_slist_free(data->callbacks);
 266         g_dbus_remove_watch(data->connection, data->name_watch);
 267         g_free(data->name);
 268         g_free(data->owner);
 269         g_free(data->path);
 270         g_free(data->interface);
 271         g_free(data->member);
 272         g_free(data->argument);
 273         dbus_connection_unref(data->connection);
 274         g_free(data);
 275 }
 276
 277 static struct filter_data *filter_data_get(DBusConnection *connection,
 278                                         DBusHandleMessageFunction filter,
 279                                         const char *sender,
 280                                         const char *path,
 281                                         const char *interface,
 282                                         const char *member,
 283                                         const char *argument)
 284 {
 285         struct filter_data *data;
 286         const char *name = NULL, *owner = NULL;
 287
 288         if (filter_data_find(connection) == NULL) {
 289                 if (!dbus_connection_add_filter(connection,
 290                                         message_filter, NULL, NULL)) {
 291                         error("dbus_connection_add_filter() failed");
 292                         return NULL;
 293                 }
 294         }
 295
 296         if (sender == NULL)
 297                 goto proceed;
 298
 299         if (sender[0] == ':')
 300                 owner = sender;
 301         else
 302                 name = sender;
 303
 304 proceed:
 305         data = filter_data_find_match(connection, name, owner, path,
 306                                                 interface, member, argument);
 307         if (data)
 308                 return data;
 309
 310         data = g_new0(struct filter_data, 1);
 311
 312         data->connection = dbus_connection_ref(connection);
 313         data->name = g_strdup(name);
 314         data->owner = g_strdup(owner);
 315         data->path = g_strdup(path);
 316         data->interface = g_strdup(interface);
 317         data->member = g_strdup(member);
 318         data->argument = g_strdup(argument);
 319
 320         if (!add_match(data, filter)) {
 321                 filter_data_free(data);
 322                 return NULL;
 323         }
 324
 325         listeners = g_slist_append(listeners, data);
 326
 327         return data;
 328 }
 329
 330 static struct filter_callback *filter_data_find_callback(
 331                                                 struct filter_data *data,
 332                                                 guint id)
 333 {
 334         GSList *l;
 335
 336         for (l = data->callbacks; l; l = l->next) {
 337                 struct filter_callback *cb = l->data;
 338                 if (cb->id == id)
 339                         return cb;
 340         }
 341         for (l = data->processed; l; l = l->next) {
 342                 struct filter_callback *cb = l->data;
 343                 if (cb->id == id)
 344                         return cb;
 345         }
 346
 347         return NULL;
 348 }
 349
 350 static void filter_data_call_and_free(struct filter_data *data)
 351 {
 352         GSList *l;
 353
 354         for (l = data->callbacks; l != NULL; l = l->next) {
 355                 struct filter_callback *cb = l->data;
 356                 if (cb->disc_func)
 357                         cb->disc_func(data->connection, cb->user_data);
 358                 if (cb->destroy_func)
 359                         cb->destroy_func(cb->user_data);
 360                 g_free(cb);
 361         }
 362
 363         filter_data_free(data);
 364 }
 365
 366 static struct filter_callback *filter_data_add_callback(
 367                                                 struct filter_data *data,
 368                                                 GDBusWatchFunction connect,
 369                                                 GDBusWatchFunction disconnect,
 370                                                 GDBusSignalFunction signal,
 371                                                 GDBusDestroyFunction destroy,
 372                                                 void *user_data)
 373 {
 374         struct filter_callback *cb = NULL;
 375
 376         cb = g_new0(struct filter_callback, 1);
 377
 378         cb->conn_func = connect;
 379         cb->disc_func = disconnect;
 380         cb->signal_func = signal;
 381         cb->destroy_func = destroy;
 382         cb->user_data = user_data;
 383         cb->id = ++listener_id;
 384
 385         if (data->lock)
 386                 data->processed = g_slist_append(data->processed, cb);
 387         else
 388                 data->callbacks = g_slist_append(data->callbacks, cb);
 389
 390         return cb;
 391 }
 392
 393 static void service_data_free(struct service_data *data)
 394 {
 395         struct filter_callback *callback = data->callback;
 396
 397         dbus_connection_unref(data->conn);
 398
 399         if (data->call)
 400                 dbus_pending_call_unref(data->call);
 401
 402         if (data->id)
 403                 g_source_remove(data->id);
 404
 405         g_free(data->name);
 406         g_free(data);
 407
 408         callback->data = NULL;
 409 }
 410
 411 /* Returns TRUE if data is freed */
 412 static gboolean filter_data_remove_callback(struct filter_data *data,
 413                                                 struct filter_callback *cb)
 414 {
 415         data->callbacks = g_slist_remove(data->callbacks, cb);
 416         data->processed = g_slist_remove(data->processed, cb);
 417
 418         /* Cancel pending operations */
 419         if (cb->data) {
 420                 if (cb->data->call)
 421                         dbus_pending_call_cancel(cb->data->call);
 422                 service_data_free(cb->data);
 423         }
 424
 425         if (cb->destroy_func)
 426                 cb->destroy_func(cb->user_data);
 427
 428         g_free(cb);
 429
 430         /* Don't remove the filter if other callbacks exist or data is lock
 431          * processing callbacks */
 432         if (data->callbacks || data->lock)
 433                 return FALSE;
 434
 435         if (data->registered && !remove_match(data))
 436                 return FALSE;
 437
 438         listeners = g_slist_remove(listeners, data);
 439         filter_data_free(data);
 440
 441         return TRUE;
 442 }
 443
 444 static DBusHandlerResult signal_filter(DBusConnection *connection,
 445                                         DBusMessage *message, void *user_data)
 446 {
 447         struct filter_data *data = user_data;
 448         struct filter_callback *cb;
 449
 450         while (data->callbacks) {
 451                 cb = data->callbacks->data;
 452
 453                 if (cb->signal_func && !cb->signal_func(connection, message,
 454                                                         cb->user_data)) {
 455                         if (filter_data_remove_callback(data, cb))
 456                                 break;
 457
 458                         continue;
 459                 }
 460
 461                 /* Check if the watch was removed/freed by the callback
 462                  * function */
 463                 if (!g_slist_find(data->callbacks, cb))
 464                         continue;
 465
 466                 data->callbacks = g_slist_remove(data->callbacks, cb);
 467                 data->processed = g_slist_append(data->processed, cb);
 468         }
 469
 470         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 471 }
 472
 473 static void update_name_cache(const char *name, const char *owner)
 474 {
 475         GSList *l;
 476
 477         for (l = listeners; l != NULL; l = l->next) {
 478                 struct filter_data *data = l->data;
 479
 480                 if (g_strcmp0(data->name, name) != 0)
 481                         continue;
 482
 483                 g_free(data->owner);
 484                 data->owner = g_strdup(owner);
 485         }
 486 }
 487
 488 static const char *check_name_cache(const char *name)
 489 {
 490         GSList *l;
 491
 492         for (l = listeners; l != NULL; l = l->next) {
 493                 struct filter_data *data = l->data;
 494
 495                 if (g_strcmp0(data->name, name) != 0)
 496                         continue;
 497
 498                 return data->owner;
 499         }
 500
 501         return NULL;
 502 }
 503
 504 static DBusHandlerResult service_filter(DBusConnection *connection,
 505                                         DBusMessage *message, void *user_data)
 506 {
 507         struct filter_data *data = user_data;
 508         struct filter_callback *cb;
 509         char *name, *old, *new;
 510
 511         if (!dbus_message_get_args(message, NULL,
 512                                 DBUS_TYPE_STRING, &name,
 513                                 DBUS_TYPE_STRING, &old,
 514                                 DBUS_TYPE_STRING, &new,
 515                                 DBUS_TYPE_INVALID)) {
 516                 error("Invalid arguments for NameOwnerChanged signal");
 517                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 518         }
 519
 520         update_name_cache(name, new);
 521
 522         while (data->callbacks) {
 523                 cb = data->callbacks->data;
 524
 525                 if (*new == '\0') {
 526                         if (cb->disc_func)
 527                                 cb->disc_func(connection, cb->user_data);
 528                 } else {
 529                         if (cb->conn_func)
 530                                 cb->conn_func(connection, cb->user_data);
 531                 }
 532
 533                 /* Check if the watch was removed/freed by the callback
 534                  * function */
 535                 if (!g_slist_find(data->callbacks, cb))
 536                         continue;
 537
 538                 /* Only auto remove if it is a bus name watch */
 539                 if (data->argument[0] == ':' &&
 540                                 (cb->conn_func == NULL || cb->disc_func == NULL)) {
 541                         if (filter_data_remove_callback(data, cb))
 542                                 break;
 543
 544                         continue;
 545                 }
 546
 547                 data->callbacks = g_slist_remove(data->callbacks, cb);
 548                 data->processed = g_slist_append(data->processed, cb);
 549         }
 550
 551         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 552 }
 553
 554
 555 static DBusHandlerResult message_filter(DBusConnection *connection,
 556                                         DBusMessage *message, void *user_data)
 557 {
 558         struct filter_data *data;
 559         const char *sender, *path, *iface, *member, *arg = NULL;
 560         GSList *current, *delete_listener = NULL;
 561
 562         /* Only filter signals */
 563         if (dbus_message_get_type(message) != DBUS_MESSAGE_TYPE_SIGNAL)
 564                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 565
 566         sender = dbus_message_get_sender(message);
 567         path = dbus_message_get_path(message);
 568         iface = dbus_message_get_interface(message);
 569         member = dbus_message_get_member(message);
 570         dbus_message_get_args(message, NULL, DBUS_TYPE_STRING, &arg, DBUS_TYPE_INVALID);
 571
 572         /* If sender != NULL it is always the owner */
 573
 574         for (current = listeners; current != NULL; current = current->next) {
 575                 data = current->data;
 576
 577                 if (connection != data->connection)
 578                         continue;
 579
 580                 if (!sender && data->owner)
 581                         continue;
 582
 583                 if (data->owner && g_str_equal(sender, data->owner) == FALSE)
 584                         continue;
 585
 586                 if (data->path && g_str_equal(path, data->path) == FALSE)
 587                         continue;
 588
 589                 if (data->interface && g_str_equal(iface,
 590                                                 data->interface) == FALSE)
 591                         continue;
 592
 593                 if (data->member && g_str_equal(member, data->member) == FALSE)
 594                         continue;
 595
 596                 if (data->argument && g_str_equal(arg,
 597                                                 data->argument) == FALSE)
 598                         continue;
 599
 600                 if (data->handle_func) {
 601                         data->lock = TRUE;
 602
 603                         data->handle_func(connection, message, data);
 604
 605                         data->callbacks = data->processed;
 606                         data->processed = NULL;
 607                         data->lock = FALSE;
 608                 }
 609
 610                 if (!data->callbacks)
 611                         delete_listener = g_slist_prepend(delete_listener,
 612                                                                 current);
 613         }
 614
 615         if (delete_listener == NULL)
 616                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 617
 618         for (current = delete_listener; current != NULL;
 619                                         current = delete_listener->next) {
 620                 GSList *l = current->data;
 621
 622                 data = l->data;
 623
 624                 /* Has any other callback added callbacks back to this data? */
 625                 if (data->callbacks != NULL)
 626                         continue;
 627
 628                 remove_match(data);
 629                 listeners = g_slist_delete_link(listeners, l);
 630
 631                 filter_data_free(data);
 632         }
 633
 634         g_slist_free(delete_listener);
 635
 636         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 637 }
 638
 639 static gboolean update_service(void *user_data)
 640 {
 641         struct service_data *data = user_data;
 642         struct filter_callback *cb = data->callback;
 643         DBusConnection *conn;
 644
 645         conn = dbus_connection_ref(data->conn);
 646         service_data_free(data);
 647
 648         if (cb->conn_func)
 649                 cb->conn_func(conn, cb->user_data);
 650
 651         dbus_connection_unref(conn);
 652
 653         return FALSE;
 654 }
 655
 656 static void service_reply(DBusPendingCall *call, void *user_data)
 657 {
 658         struct service_data *data = user_data;
 659         DBusMessage *reply;
 660         DBusError err;
 661
 662         reply = dbus_pending_call_steal_reply(call);
 663         if (reply == NULL)
 664                 return;
 665
 666         dbus_error_init(&err);
 667
 668         if (dbus_set_error_from_message(&err, reply))
 669                 goto fail;
 670
 671         if (dbus_message_get_args(reply, &err,
 672                                         DBUS_TYPE_STRING, &data->owner,
 673                                                 DBUS_TYPE_INVALID) == FALSE)
 674                 goto fail;
 675
 676         update_service(data);
 677
 678         goto done;
 679
 680 fail:
 681         error("%s", err.message);
 682         dbus_error_free(&err);
 683         service_data_free(data);
 684 done:
 685         dbus_message_unref(reply);
 686 }
 687
 688 static void check_service(DBusConnection *connection,
 689                                         const char *name,
 690                                         struct filter_callback *callback)
 691 {
 692         DBusMessage *message;
 693         struct service_data *data;
 694
 695         data = g_try_malloc0(sizeof(*data));
 696         if (data == NULL) {
 697                 error("Can't allocate data structure");
 698                 return;
 699         }
 700
 701         data->conn = dbus_connection_ref(connection);
 702         data->name = g_strdup(name);
 703         data->callback = callback;
 704         callback->data = data;
 705
 706         data->owner = check_name_cache(name);
 707         if (data->owner != NULL) {
 708                 data->id = g_idle_add(update_service, data);
 709                 return;
 710         }
 711
 712         message = dbus_message_new_method_call(DBUS_SERVICE_DBUS,
 713                         DBUS_PATH_DBUS, DBUS_INTERFACE_DBUS, "GetNameOwner");
 714         if (message == NULL) {
 715                 error("Can't allocate new message");
 716                 g_free(data);
 717                 return;
 718         }
 719
 720         dbus_message_append_args(message, DBUS_TYPE_STRING, &name,
 721                                                         DBUS_TYPE_INVALID);
 722
 723         if (dbus_connection_send_with_reply(connection, message,
 724                                                         &data->call, -1) == FALSE) {
 725                 error("Failed to execute method call");
 726                 g_free(data);
 727                 goto done;
 728         }
 729
 730         if (data->call == NULL) {
 731                 error("D-Bus connection not available");
 732                 g_free(data);
 733                 goto done;
 734         }
 735
 736         dbus_pending_call_set_notify(data->call, service_reply, data, NULL);
 737
 738 done:
 739         dbus_message_unref(message);
 740 }
 741
 742 guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
 743                                 GDBusWatchFunction connect,
 744                                 GDBusWatchFunction disconnect,
 745                                 void *user_data, GDBusDestroyFunction destroy)
 746 {
 747         struct filter_data *data;
 748         struct filter_callback *cb;
 749
 750         if (name == NULL)
 751                 return 0;
 752
 753         data = filter_data_get(connection, service_filter,
 754                                 DBUS_SERVICE_DBUS, DBUS_PATH_DBUS,
 755                                 DBUS_INTERFACE_DBUS, "NameOwnerChanged",
 756                                 name);
 757         if (data == NULL)
 758                 return 0;
 759
 760         cb = filter_data_add_callback(data, connect, disconnect, NULL, destroy,
 761                                         user_data);
 762         if (cb == NULL)
 763                 return 0;
 764
 765         if (connect)
 766                 check_service(connection, name, cb);
 767
 768         return cb->id;
 769 }
 770
 771 guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
 772                                 GDBusWatchFunction func,
 773                                 void *user_data, GDBusDestroyFunction destroy)
 774 {
 775         return g_dbus_add_service_watch(connection, name, NULL, func,
 776                                                         user_data, destroy);
 777 }
 778
 779 guint g_dbus_add_signal_watch(DBusConnection *connection,
 780                                 const char *sender, const char *path,
 781                                 const char *interface, const char *member,
 782                                 GDBusSignalFunction function, void *user_data,
 783                                 GDBusDestroyFunction destroy)
 784 {
 785         struct filter_data *data;
 786         struct filter_callback *cb;
 787
 788         data = filter_data_get(connection, signal_filter, sender, path,
 789                                 interface, member, NULL);
 790         if (data == NULL)
 791                 return 0;
 792
 793         cb = filter_data_add_callback(data, NULL, NULL, function, destroy,
 794                                         user_data);
 795         if (cb == NULL)
 796                 return 0;
 797
 798         if (data->name != NULL && data->name_watch == 0)
 799                 data->name_watch = g_dbus_add_service_watch(connection,
 800                                                         data->name, NULL,
 801                                                         NULL, NULL, NULL);
 802
 803         return cb->id;
 804 }
 805
 806 guint g_dbus_add_properties_watch(DBusConnection *connection,
 807                                 const char *sender, const char *path,
 808                                 const char *interface,
 809                                 GDBusSignalFunction function, void *user_data,
 810                                 GDBusDestroyFunction destroy)
 811 {
 812         struct filter_data *data;
 813         struct filter_callback *cb;
 814
 815         data = filter_data_get(connection, signal_filter, sender, path,
 816                                 DBUS_INTERFACE_PROPERTIES, "PropertiesChanged",
 817                                 interface);
 818         if (data == NULL)
 819                 return 0;
 820
 821         cb = filter_data_add_callback(data, NULL, NULL, function, destroy,
 822                                         user_data);
 823         if (cb == NULL)
 824                 return 0;
 825
 826         if (data->name != NULL && data->name_watch == 0)
 827                 data->name_watch = g_dbus_add_service_watch(connection,
 828                                                         data->name, NULL,
 829                                                         NULL, NULL, NULL);
 830
 831         return cb->id;
 832 }
 833
 834 gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
 835 {
 836         struct filter_data *data;
 837         struct filter_callback *cb;
 838         GSList *ldata;
 839
 840         if (id == 0)
 841                 return FALSE;
 842
 843         for (ldata = listeners; ldata; ldata = ldata->next) {
 844                 data = ldata->data;
 845
 846                 cb = filter_data_find_callback(data, id);
 847                 if (cb) {
 848                         filter_data_remove_callback(data, cb);
 849                         return TRUE;
 850                 }
 851         }
 852
 853         return FALSE;
 854 }
 855
 856 void g_dbus_remove_all_watches(DBusConnection *connection)
 857 {
 858         struct filter_data *data;
 859
 860         while ((data = filter_data_find(connection))) {
 861                 listeners = g_slist_remove(listeners, data);
 862                 filter_data_call_and_free(data);
 863         }
 864 }