ip6_output_ipsec_pmtu_update
int ip6_output_ipsec_pmtu_update(struct tdb *, struct route *,
error = ip6_output_ipsec_pmtu_update(tdb, ro, &dst, ifidx,
ip6_output_ipsec_pmtu_update(tdb, ro, &dst, ifidx, rtableid, 0);