+bool session_is_controller(Session *s, const char *sender) {
+ assert(s);
+
+ return streq_ptr(s->controller, sender);
+}
+
+int session_set_controller(Session *s, const char *sender, bool force) {
+ char *t;
+ int r;
+
+ assert(s);
+ assert(sender);
+
+ if (session_is_controller(s, sender))
+ return 0;
+ if (s->controller && !force)
+ return -EBUSY;
+
+ t = strdup(sender);
+ if (!t)
+ return -ENOMEM;
+
+ r = manager_watch_busname(s->manager, sender);
+ if (r) {
+ free(t);
+ return r;
+ }
+
+ session_drop_controller(s);
+
+ s->controller = t;
+ return 0;
+}
+
+void session_drop_controller(Session *s) {
+ SessionDevice *sd;
+
+ assert(s);
+
+ if (!s->controller)
+ return;
+
+ manager_drop_busname(s->manager, s->controller);
+ free(s->controller);
+ s->controller = NULL;
+
+ /* Drop all devices as they're now unused. Do that after the controller
+ * is released to avoid sending out useles dbus signals. */
+ while ((sd = hashmap_first(s->devices)))
+ session_device_free(sd);
+}
+