OT: In Cilium we run similar NAT46/64 translation for XDP and tc/BPF
for our LB services [4] (that is,
v4 VIP with v6 backends, and v6 VIP with v4 backends).
[4]
https://github.com/cilium/cilium/blob/master/bpf/lib/nat_46x64.h
https://github.com/cilium/cilium/blob/master/test/nat46x64/test.sh
It is complicated for me, my case doesnot use XDP driver.I use xdp_dummy
just to enable veth NAPI GRO, not real XDP driver code. My test case is
simple and enough for my patch, I think. I have covered tcp and udp,
normal and SO_SEGMENT.