libnm-util: allow unknown setting types in nm_connection_get_virtual_iface_name()

Allow calling nm_connection_get_virtual_iface_name() on a non-verified
connection by not asserting asserting against a valid base-setting.

On nma-1-0 branch, nm-applet can crash with:

    #3  0x00007ffff2993a7a in g_assertion_message_expr (domain=0x7ffff51fad86 "libnm-util", file=0x7ffff51fb728 "nm-connection.c", line=320, func=0x7ffff51fc028 "_get_type_setting", expr=<optimized out>) at gtestutils.c:2444
    #4  0x00007ffff51ac52f in _get_type_setting (connection=0xa3c160 [NMRemoteConnection]) at nm-connection.c:320
    #5  0x00007ffff51ac341 in nm_connection_get_virtual_iface_name (connection=0xa3c160 [NMRemoteConnection]) at nm-connection.c:1436
    #6  0x0000000000415bdc in add_virtual_items (type=type@entry=0x43c11d "bridge", all_devices=all_devices@entry=0x7f6580, all_connections=all_connections@entry=0x9354a0, menu=menu@entry=0x922990 [GtkMenu], applet=applet@entry=0x6cc000 [NMApplet]) at applet.c:1640
    #7  0x00000000004176f6 in nma_menu_add_devices (menu=menu@entry=0x922990 [GtkMenu], applet=applet@entry=0x6cc000 [NMApplet]) at applet.c:1713
    #8  0x0000000000418315 in nma_menu_show_cb (menu=0x922990 [GtkMenu], applet=0x6cc000 [NMApplet]) at applet.c:1974

where the connection type is "tun".

Note that libnm accepts invalid connections and exposes them to the
user (albeit issuing a warning). Later on there are many places where
that can lead to further g_return*(), which is ugly indeed.
At least, we should not assert against valid connections (because that
crashes the user) and there is a well known fact that the base setting
will be missing for tun settings. No need to even warn about that in
nm_connection_get_virtual_iface_name() (we already got the warning
during replace_settings).

1 files changed, 11 insertions, 24 deletions

diff --git a/libnm-util/nm-connection.c b/libnm-util/nm-connection.c
index 884ed2e12c..ea1492b743 100644
--- a/libnm-util/nm-connection.c
+++ b/libnm-util/nm-connection.c
@@ -300,28 +300,6 @@ nm_connection_get_setting_by_name (NMConnection *connection, const char *name)
 	return type ? nm_connection_get_setting (connection, type) : NULL;
 }
 
-/* not exposed until we actually need it */
-static NMSetting *
-_get_type_setting (NMConnection *connection)
-{
-	NMSettingConnection *s_con;
-	const char *type;
-	NMSetting *base;
-
-	g_return_val_if_fail (NM_IS_CONNECTION (connection), NULL);
-
-	s_con = nm_connection_get_setting_connection (connection);
-	g_assert (s_con);
-
-	type = nm_setting_connection_get_connection_type (s_con);
-	g_assert (type);
-
-	base = nm_connection_get_setting_by_name (connection, type);
-	g_assert (base);
-
-	return base;
-}
-
 static gboolean
 validate_permissions_type (GHashTable *hash, GError **error)
 {
@@ -1429,12 +1407,21 @@ nm_connection_get_interface_name (NMConnection *connection)
 const char *
 nm_connection_get_virtual_iface_name (NMConnection *connection)
 {
+	NMSettingConnection *s_con;
+	const char *type;
 	NMSetting *base;
 
 	g_return_val_if_fail (NM_IS_CONNECTION (connection), NULL);
 
-	base = _get_type_setting (connection);
-	g_assert (base);
+	s_con = nm_connection_get_setting_connection (connection);
+	g_return_val_if_fail (s_con, NULL);
+
+	type = nm_setting_connection_get_connection_type (s_con);
+	g_return_val_if_fail (type, NULL);
+
+	base = nm_connection_get_setting_by_name (connection, type);
+	if (!base)
+		return NULL;
 
 	return nm_setting_get_virtual_iface_name (base);
 }