gdbus/watch.c

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