dbus: Terminate cleanly on messagebus shutdown

By default, dbus_connection_dispatch() will call _exit() if the bus
connection has been closed. This caused wpa_supplicant to terminate
without properly cleaning up after itself.

To ensure that we terminate cleanly when the messagebus terminates,
override the exit_on_disconnect behavior and install a filter to handle
libdbus's "Disconnected" signal.

[Bug 474]

Signed-hostap: Daniel Gnoutcheff <daniel@gnoutcheff.name>

diff --git a/wpa_supplicant/dbus/dbus_common.c b/wpa_supplicant/dbus/dbus_common.c
index 5d0e31e276c77959504917f32e3b645e705a49be..6caf740ecc0abe062993eb61f46348676ff14e5a 100644 (file)
--- a/wpa_supplicant/dbus/dbus_common.c
+++ b/wpa_supplicant/dbus/dbus_common.c
@@ -17,6 +17,7 @@
 #include "dbus_common_i.h"
 #include "dbus_new.h"
 #include "dbus_old.h"
+#include "../wpa_supplicant_i.h"
 
 
 #ifndef SIGPOLL
@@ -257,6 +258,22 @@ static int integrate_with_eloop(struct wpas_dbus_priv *priv)
 }
 
 
+static DBusHandlerResult disconnect_filter(DBusConnection *conn,
+                                           DBusMessage *message, void *data)
+{
+       struct wpas_dbus_priv *priv = data;
+
+       if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL,
+                                  "Disconnected")) {
+               wpa_printf(MSG_DEBUG, "dbus: bus disconnected, terminating");
+               dbus_connection_set_exit_on_disconnect(conn, FALSE);
+               wpa_supplicant_terminate_proc(priv->global);
+               return DBUS_HANDLER_RESULT_HANDLED;
+       } else
+               return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+
 static int wpas_dbus_init_common(struct wpas_dbus_priv *priv)
 {
        DBusError error;
@@ -265,7 +282,10 @@ static int wpas_dbus_init_common(struct wpas_dbus_priv *priv)
        /* Get a reference to the system bus */
        dbus_error_init(&error);
        priv->con = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
-       if (!priv->con) {
+       if (priv->con) {
+               dbus_connection_add_filter(priv->con, disconnect_filter, priv,
+                                          NULL);
+       } else {
                wpa_printf(MSG_ERROR, "dbus: Could not acquire the system "
                           "bus: %s - %s", error.name, error.message);
                ret = -1;
@@ -304,6 +324,9 @@ static void wpas_dbus_deinit_common(struct wpas_dbus_priv *priv)
                                                    NULL, NULL, NULL);
                dbus_connection_set_timeout_functions(priv->con, NULL, NULL,
                                                      NULL, NULL, NULL);
+               dbus_connection_remove_filter(priv->con, disconnect_filter,
+                                             priv);
+
                dbus_connection_unref(priv->con);
        }