vcl: support connected udp listens

Request connected udp listener behavior by setting
VPPCOM_ATTR_SET_CONNECTED attribute with vppcom_session_attr

Type: feature

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Iba95155c0f41cea8c6e1a4263946270d49c213ac
diff --git a/src/vcl/vppcom.h b/src/vcl/vppcom.h
index e2e0ae7..c61de37 100644
--- a/src/vcl/vppcom.h
+++ b/src/vcl/vppcom.h
@@ -160,6 +160,7 @@
   VPPCOM_ATTR_SET_TCP_USER_MSS,
   VPPCOM_ATTR_SET_SHUT,
   VPPCOM_ATTR_GET_SHUT,
+  VPPCOM_ATTR_SET_CONNECTED,
 } vppcom_attr_op_t;
 
 typedef struct _vcl_poll