[LARTC] same address range, different interfaces

[Ira Abramov]

Hey there, I wish people threw in more ideas...

what I tried now is this: my problem is that I need to route the packet
on the way out according to the original destination, but the only place
it will NAT the destination is before routing, so what I did waqs mark
packets with the netfilter MARK target and then have iproute2's code
select the routing table based on the fwmark. it's covoluted but should
work in theory:

1) MARK the incoming packet in table mangle on chain PREROUTING and
   OUTPUT
2) add a rule to the RPDB to map the NATsource based on the source and
   iface it came by, and then it goes to table main be default
   (problem! it should be a map based on the destination!)
3) open a new table (same ID as the MARK for conveniance) and add NAT to
   destination back to its real address (thus losing the original
   target, all I have left is the MARK to route with)
4) packet goes back to traverse the RPDB, where I catch it with another,
   lower priority rule than (2) based on the fwmark, sending it to the
   table I opened in (3) where I have a route to the right interface for
   the real address.

now this would work in theory if I could do (2) as NAT and then traverse
the RPDB again without sending it to a specific lookup table, is this
making sense? or can I send it to the local table and it will traverse
the rest of the RPDB when it gives up? am I missing another way of doing
this without a routing table per interface?

Any and all help is appreciated in advance,
Thanks,
Ira.



-- 
The little prince
Ira Abramov
http://ira.abramov.org/email/