CTA_TUPLE_MASTER
[CTA_TUPLE_MASTER] = { .type = NLA_NESTED },
if (cda[CTA_NAT_SRC] || cda[CTA_NAT_DST] || cda[CTA_TUPLE_MASTER])
if (cda[CTA_TUPLE_MASTER]) {
err = ctnetlink_parse_tuple(cda, &master, CTA_TUPLE_MASTER,
nest_parms = nla_nest_start(skb, CTA_TUPLE_MASTER);