Re: [libvirt-users] netfilter+libvirt=(smth got broken?)
Hi Eric,
On Wed, Mar 20, 2013 at 09:18:21PM -0600, Eric Blake wrote:
[...]
> By looking at the changes you made:
>
>> --A FI-vnet0 -p tcp -m tcp --sport 110 -m conntrack --ctstate
>> ESTABLISHED -m conntrack --ctdir ORIGINAL -j RETURN
>> +-A FI-vnet0 -p tcp -m tcp --sport 110 -m conntrack --ctstate
>> ESTABLISHED -m conntrack --ctdir REPLY -j RETURN
>
> The first rule looks wrong to me indeed, traffic coming in the
> original direction will initiate the connection to destination port
> TCP/110. Therefore, your change is correct.
Correct for the new kernel interpretation, but we also want to support
use of libvirt with older kernels, preferably with a runtime check so
that a binary compiled on an older kernel will still work after a kernel
upgrade.
My suggestion is to relax that rule-set that you're using, ie. remove
the --ctdir. The connection tracking table and the TCP tracker already
take care for those invalid situations that you were trying to catch
with that --ctdir. You only have to add an iptables rule somewhere to
catch invalid packets.
I can also pass that patch to -stable starting 2.6.32 if that helps,
but you will still have to fix your rule-set.