Masquerade based on skb->mark ?
Ben Greear
greearb at candelatech.com
Wed Apr 25 05:06:52 CEST 2007
I'm now trying to masquerade packets that have been marked
a certain way. I'm using these commands:
# I'm not sure this is doing the right thing, but it is not giving errors.
iptables -A POSTROUTING -t nat -j MASQUERADE -m mark --mark 10001
# This appears to work as planned.
iptables -t mangle -A PREROUTING -i eth1 -j MARK --set-mark 10001
iptables -t mangle -A PREROUTING -i eth2 -j MARK --set-mark 10001
I added a u32 'mark' field to the conn-track tuple, and I now get
different conn-tracking objects for the same source/dest but with
different 'mark'. However, the ct->status bit does not have the
IPS_SRC_NAT flag set.
I think I need to figure out what code creates the initial conn-track
and make sure it is setting the status bits correctly based on the
skb->mark, but I am not sure where this code exists.
Any ideas on where to start looking? I've been trying to follow
the code path in the netfilter/nat logic, but it's proving
slow going!
Thanks,
Ben
PS. If anyone does this sort of work for hire, please contact me off-list.
--
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc http://www.candelatech.com
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