MPLS_LABEL_IPV4NULL
case MPLS_LABEL_IPV4NULL:
kn->r.local_label = MPLS_LABEL_IPV4NULL;
if (label == MPLS_LABEL_IPV4NULL) {
*label != MPLS_LABEL_IPV4NULL &&
MPLS_LABEL_IPV4NULL);
return (MPLS_LABEL_IPV4NULL);
case MPLS_LABEL_IPV4NULL: