Merge branch 'master' into openslx

1 files changed, 22 insertions, 0 deletions

diff --git a/src/core/interface.c b/src/core/interface.c
index 402aa4541..34a4180a5 100644
--- a/src/core/interface.c
+++ b/src/core/interface.c
@@ -81,9 +81,14 @@ struct interface null_intf = INTF_INIT ( null_intf_desc );
  * interface is updated to point to the new destination interface.
  */
 void intf_plug ( struct interface *intf, struct interface *dest ) {
+
+	if ( intf == &null_intf )
+		return;
+
 	DBGC ( INTF_COL ( intf ),
 	       "INTF " INTF_INTF_FMT " replug to " INTF_FMT "\n",
 	       INTF_INTF_DBG ( intf, intf->dest ), INTF_DBG ( dest ) );
+
 	intf_get ( dest );
 	intf_put ( intf->dest );
 	intf->dest = dest;
@@ -386,6 +391,23 @@ void intfs_restart ( int rc, ... ) {
 }
 
 /**
+ * Insert a filter interface
+ *
+ * @v intf		Object interface
+ * @v upper		Upper end of filter
+ * @v lower		Lower end of filter
+ */
+void intf_insert ( struct interface *intf, struct interface *upper,
+		   struct interface *lower ) {
+	struct interface *dest = intf->dest;
+
+	intf_get ( dest );
+	intf_plug_plug ( intf, upper );
+	intf_plug_plug ( lower, dest );
+	intf_put ( dest );
+}
+
+/**
  * Poke an object interface
  *
  * @v intf		Object interface