>>I've been thinking about setting up a v6-to-v4 gateway, somewhat akin
>>to what faith(4)/faithd(8) provide.  However, I want it to be
>>port-independent.
>>
>>This means (a) a way to bind a listening TCP socket without specifying
>>a port and (b) a way to bind a socket to just the /96 corresponding to
>>the mapped address space.  (Actually, (b) is unnecessary if I'm willing
>>to give up on all ordinary incoming v6 connections to the machine, but
>>I'm not.)
>	basically, faith(4) is used for tagging packets to be grabbed by
>	IPV6_FAITH sockets.  if we can tag traffic by other means, we can
>	grab these traffic.  my preference is to have some packet filter
>	directive to mark traffic, and avoid tweaking pcb layer.

	err, i don't like tweaking pcb layer for "any port" bind(2) support,
	hence the above does not satisfy your requirement...

itojun