iptables mangle table PREROUTING rule with -o flag

["John B Dunning/NS/WSC" <jodunni1@xxxxxxx>]

Greetings all,

I realize from the subject line this
makes little sense but here's the scenario:

I'm trying to shape (via priority -
not bandwidth) peer to peer traffic from a number of clients.  Currently
I use an IMQ device to bring all their outbound (inbound to me - outbound
to Inet) traffic together to work with policies all at the same time.  I'm
testing the IP-P2P modules for IP tables and so far they seem to grab the
traffic pretty well but here's the problem.  I'd like to set the priority
for all P2P traffic in one shot - thus I have to do it at my IMQ device
via a -J CLASSIFY target in iptables.  Problem is that the classify
target requires that the device with the classes be the "-o device"
parameter so it knows which device to query for the classes - but you can't
use -o with the PREROUTING list in the mangle table because normally it
would make no sense.  Would it be possible to modify iptables to allow
-o device in the PREROUTING list if the device type is IMQ??

Does this make any sense??

John Dunning
Asst Dir Net & Tech Svcs
Wayne State College