new ip settings method acceptibility

["Shawn J. Goff" <shawn7400 gmail com>]

I'm considering adding a new method for ip settings and I'd like some
input before I go write the whole thing. Primarily, I'm wondering if
this feature would have any chance of being merged since it will have
very few users. My method accomplishes a similar thing to the "shared"
connection method, but it's a little different. It will be called
"forwarded" or "proxied". It is used for connecting to a network on
behalf of another host. It's how I make my cellular wireless router
work in situations where I need to offer the wireless connection as if
it was just a normal Ethernet connection.

The setup involves connecting to a network normally, but not adding
the acquired (via PPP, DHCP, etc) address to the interface - a
different address is added the to interface instead and the original
address from the network is saved; dhcpd is configured to offer that
single address on the other interfaces. Additionally, an SNAT target
is added to the nat table's POSTROUTING chain so that this middle
device can also use the connection.