bt: create D-Bus proxy for NMBluez4Adapter asynchronously

And some fixes:

  - proxy creation may fail. Don't handle it by retrying,
    but at least don't access the invalid proxy instance.

  - get_properties_cb() did not take a reference to @self
    nor was the operation cancellable. This leads to crash
    if the instance gets destroyed early.

1 files changed, 68 insertions, 25 deletions

diff --git a/src/devices/bluetooth/nm-bluez4-adapter.c b/src/devices/bluetooth/nm-bluez4-adapter.c
index c0c1be30b7..5c09582b04 100644
--- a/src/devices/bluetooth/nm-bluez4-adapter.c
+++ b/src/devices/bluetooth/nm-bluez4-adapter.c
@@ -49,6 +49,7 @@ static guint signals[LAST_SIGNAL] = { 0 };
 typedef struct {
 	char *path;
 	GDBusProxy *proxy;
+	GCancellable *proxy_cancellable;
 	gboolean initialized;
 
 	char *address;
@@ -198,19 +199,28 @@ device_removed (GDBusProxy *proxy, const char *path, gpointer user_data)
 static void
 get_properties_cb (GObject *proxy, GAsyncResult *result, gpointer user_data)
 {
-	NMBluez4Adapter *self = NM_BLUEZ4_ADAPTER (user_data);
-	NMBluez4AdapterPrivate *priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
-	GError *err = NULL;
+	NMBluez4Adapter *self;
+	NMBluez4AdapterPrivate *priv;
+	gs_free_error GError *error = NULL;
 	GVariant *ret, *properties;
 	char **devices;
 	int i;
 
 	ret = _nm_dbus_proxy_call_finish (G_DBUS_PROXY (proxy), result,
-	                                  G_VARIANT_TYPE ("(a{sv})"), &err);
+	                                  G_VARIANT_TYPE ("(a{sv})"), &error);
+
+	if (   !ret
+	    && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		return;
+
+	self = NM_BLUEZ4_ADAPTER (user_data);
+	priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
+
+	g_clear_object (&priv->proxy_cancellable);
+
 	if (!ret) {
-		g_dbus_error_strip_remote_error (err);
-		nm_log_warn (LOGD_BT, "bluez error getting adapter properties: %s", err->message);
-		g_error_free (err);
+		g_dbus_error_strip_remote_error (error);
+		nm_log_warn (LOGD_BT, "bluez error getting adapter properties: %s", error->message);
 		goto done;
 	}
 
@@ -233,15 +243,43 @@ done:
 }
 
 static void
-query_properties (NMBluez4Adapter *self)
+_proxy_new_cb (GObject *source_object,
+               GAsyncResult *result,
+               gpointer user_data)
 {
-	NMBluez4AdapterPrivate *priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
+	NMBluez4Adapter *self;
+	NMBluez4AdapterPrivate *priv;
+	gs_free_error GError *error = NULL;
+	GDBusProxy *proxy;
+
+	proxy = g_dbus_proxy_new_for_bus_finish (result, &error);
+	if (   !proxy
+	    && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		return;
+
+	self = user_data;
+	priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
+
+	if (!proxy) {
+		nm_log_warn (LOGD_BT, "bluez error creating D-Bus proxy: %s", error->message);
+		g_clear_object (&priv->proxy_cancellable);
+		g_signal_emit (self, signals[INITIALIZED], 0, priv->initialized);
+		return;
+	}
+
+	priv->proxy = proxy;
+
+	_nm_dbus_signal_connect (priv->proxy, "DeviceCreated", G_VARIANT_TYPE ("(o)"),
+	                         G_CALLBACK (device_created), self);
+	_nm_dbus_signal_connect (priv->proxy, "DeviceRemoved", G_VARIANT_TYPE ("(o)"),
+	                         G_CALLBACK (device_removed), self);
 
 	g_dbus_proxy_call (priv->proxy, "GetProperties",
 	                   NULL,
 	                   G_DBUS_CALL_FLAGS_NONE, -1,
-	                   NULL,
-	                   get_properties_cb, self);
+	                   priv->proxy_cancellable,
+	                   get_properties_cb,
+	                   self);
 }
 
 /*****************************************************************************/
@@ -316,19 +354,17 @@ nm_bluez4_adapter_new (const char *path, NMSettings *settings)
 
 	priv->settings = g_object_ref (settings);
 
-	priv->proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
-	                                             G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES,
-	                                             NULL,
-	                                             BLUEZ_SERVICE,
-	                                             priv->path,
-	                                             BLUEZ4_ADAPTER_INTERFACE,
-	                                             NULL, NULL);
-	_nm_dbus_signal_connect (priv->proxy, "DeviceCreated", G_VARIANT_TYPE ("(o)"),
-	                         G_CALLBACK (device_created), self);
-	_nm_dbus_signal_connect (priv->proxy, "DeviceRemoved", G_VARIANT_TYPE ("(o)"),
-	                         G_CALLBACK (device_removed), self);
+	priv->proxy_cancellable = g_cancellable_new ();
 
-	query_properties (self);
+	g_dbus_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
+	                          G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES,
+	                          NULL,
+	                          BLUEZ_SERVICE,
+	                          priv->path,
+	                          BLUEZ4_ADAPTER_INTERFACE,
+	                          priv->proxy_cancellable,
+	                          _proxy_new_cb,
+	                          self);
 	return self;
 }
 
@@ -339,21 +375,28 @@ dispose (GObject *object)
 	NMBluez4AdapterPrivate *priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
 	NMBluezDevice *device;
 
+	nm_clear_g_cancellable (&priv->proxy_cancellable);
+
 	while ((device = g_hash_table_find (priv->devices, _find_all, NULL)))
 		device_do_remove (self, device);
 
+	if (priv->proxy) {
+		g_signal_handlers_disconnect_by_data (priv->proxy, self);
+		g_clear_object (&priv->proxy);
+	}
+
 	G_OBJECT_CLASS (nm_bluez4_adapter_parent_class)->dispose (object);
 }
 
 static void
 finalize (GObject *object)
 {
-	NMBluez4AdapterPrivate *priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE ((NMBluez4Adapter *) object);
+	NMBluez4Adapter *self = NM_BLUEZ4_ADAPTER (object);
+	NMBluez4AdapterPrivate *priv = NM_BLUEZ4_ADAPTER_GET_PRIVATE (self);
 
 	g_hash_table_destroy (priv->devices);
 	g_free (priv->address);
 	g_free (priv->path);
-	g_object_unref (priv->proxy);
 
 	G_OBJECT_CLASS (nm_bluez4_adapter_parent_class)->finalize (object);