Re: [libvirt] [RFC] Proposal for introduction of network traffic filtering capabilities for filtering of network traffic from and to VMs

On Mon, 2010-01-25 at 14:59 +0000, Daniel P. Berrange wrote: > On Fri, Jan 22, 2010 at 01:29:16PM +0100, Gerhard Stenzel wrote: > > On Wed, 2010-01-13 at 17:36 +0000, Daniel P. Berrange wrote: ... > > The shear size of the ruleset inside the <interface> element is > rather alarming to me. Imagine if you have a guest with more > than one NIC. I'm inclined to suggest that the <interface> > element in the domain XML description should only have a single > rule > > <filter name='BLAH'/> > > and if apps wish to construct a filter, from multiple independant > sub-filters, then that should be done against the filter object's > config, rather than the domain object's config. > ... > What was the idea with the empty attributes here ? Are those > implying that the attribute value is to be filled in with the > value from the domain XML ? If so I'd probably make that more > explicit using something like $IP and $MAC to represent the > guest configured IP/MAC > ... > I don't think that '<firewall>' is the top level object to be managed > here. I would suggest that '<firewall>' and '<template>' elements are > redundant, and that <filter> should be for the top level managed objects. > The libvirt API would allow listing of existing filters, creating / deleting > filters and updating the config. The <filter> element would allow some kind > of <include> element to allow a complex filter to be built out of multiple > simpler filters. > > > Regards, > Daniel Daniel, ok, trying to combine your suggestions: - guest contains a single filter reference per interface guest.xml: ---------- <domain type='kvm'> <name>demo</name> <memory>256000</memory> <devices> <interface type="bridge"> <filter name='demofilter' ipaddr='10.0.0.1'/> </interface>

</devices> </domain> - complex filter include other filter and can contain rules complex demofilter.xml: ----------------------- <filter name='demofilter'> <include href='drop-all'/> <include href='no-arp-spoofing' srcipaddr='$IP'/> <include href='no-mac-spoofing'/> <include href='no-ip-spoofing' srcipaddr='$IP'/> <!-- no ip spoofing --> <rule action='drop' direction='out'> <ip match='no' srcipaddr='$IP'/> </rule> </filter> - simple filter contain only rules simple no-arp-spoofing.xml: --------------------------- <filter name='ARP' policy='drop'> <!-- no arp spoofing --> <!-- drop if ipaddr or macaddr does not belong to guest --> <rule action='drop' direction='out'> <arp match='no' srcmacaddr='$MAC'/> <arp match='no' srcipaddr='$IP' /> </rule> <!-- drop if ipaddr or macaddr does not belong to guest --> <rule action='drop' direction='in'> <arp match='no' dstmacaddr='$MAC'/> <arp match='no' dstipaddr='$IP' /> </rule> <!-- allow all other request or reply packets --> <rule action='allow' direction='inout'> <arp opcode='request'/> <arp opcode='reply'/> </rule> </filter> - $IP, $MAC represent the guests configured IP,MAC values If the above seems acceptable for the moment, I would suggest we verify that this is actually implementable or if we missed something.