[libvirt] [libvirt PATCHv3 05/10] allow chain modification

[David Stevens]

Stefan Berger <stefanb at linux.vnet.ibm.com> wrote on 10/17/2011 10:31:29 
AM:


> > was not.
> Yes, then I understood this correctly. See the other mails regarding the 

> problems I am seeing with it. If there was a way to figure out at what 
> position to insert a rule into an existing chain, i.e. at position 5, 
> rather than always at the end, we could use this addRules() call, 
> otherwise I find it very limiting.

        I'm not sure if I answered this already for you or not, but you
can -- by using the priority in the rule. If we don't use the policy
and so have to have a "-j DROP" at the end, then we'd want the original
filter to use "-1" (if I'm remembering correctly -- 1 before end??). You
can specify the rule be added at any point; "IP" rules would all have
the same priority, because they originate from the same line in the 
filter,
but you can use the priority to offset from the end or beginning, or
any fixed point in the chain.

                                                        +-DLS

PS - I haven't tried using negative priorities with nwfilter, but
        ebtables/iptables supports it, at least.