Patch: TPROXY support for listening sockets

this patch is not meant to provide transparently IP of clients to
the backends.

It is meant to for nginx to be able to listen on non-local IP, as
replacement for (eg.) NATing of incomming connections to local port.
My setups use LVS with direct routing and real-servers without the
public IPs, using NAT. However the problem I’m facing is IPv6 and one
option is to use TPROXY sockets to listen to (possibly large number
of) non-local IPs.

Would you recommend some other solution or is this TPROXY patch fine?