On Thu, May 17, 2018 at 05:55:39PM -0400, John Ferlan wrote: > > > On 05/17/2018 01:37 PM, Daniel P. Berrangé wrote: > > On Thu, May 17, 2018 at 01:31:04PM -0400, Laine Stump wrote: > >> On 05/15/2018 01:43 PM, Daniel P. Berrangé wrote: > >>> A typical XML representation of the virNWFilterBindingDefPtr struct > >>> looks like this: > >>> > >>> <filterbinding> > >>> <owner> > >>> <name>f25arm7</name> > >>> <uuid>12ac8b8c-4f23-4248-ae42-fdcd50c400fd</uuid> > >>> </owner> > >>> <portdev name='vnet1'/> > >>> <mac address='52:54:00:9d:81:b1'/> > >>> <filterref filter='clean-traffic'> > >>> <parameter name='MAC' value='52:54:00:9d:81:b1'/> > >>> </filterref> > >>> </filterbinding> > >> > >> > >> I haven't had time to look at this in detail yet, or to really think > >> about the comment I'm going to make, but I wanted to be sure I said it > >> right away in case there are any public API implications > >> > >> > >> By now we all know the horror by which OpenStack's networking creates a > >> separate bridge device, and connects the guest's tap device to that > >> bridge so that (in addition to other reasons) there is a place for > >> libvirt's nwfilter rules to attach (what they *really* want to connect > >> to is an Open vSwitch, but ipfilter rules aren't in the data path when a > >> tap device is connected to OVS). This atrocity could be avoided if > >> nwfilter supported OVN (OVS's ipfilter analog) directly. In order to > >> support it though, nwfilter would need to know more details about the > >> network device that it's adding rules for. (because some guests may be > >> connected to OVS and others may be connected to a standard host bridge > >> (or nothing at all) we can't just have a system-wide config to decide). > >> > >> I can't recall if there is a reasonable API to figure out what a tap > >> device is connected to, but I think such a thing may not exist and, if > >> so, we'll likely need to send some sort of indicator in the > >> NWFilterBinding XML. It *might* be simpler / more futureproof if we > >> included the <virtualport> element that is already in the domain XML > >> <interface> information - that's currently what we use to decide how to > >> connect the tap device; hopefully in the future it will continue to > >> conain everything that's needed (if we think that's inadequate, we could > >> just go for broke and include the entire <interface>, but that's > >> probably overkill. (although..... - thinking about the potential case > >> where some SRIOV network card supported some sort of filtering, if we > >> sent the entire <interface>, we would know that it was a hostdev...) > >> > >> I started typing this wondering if the C API might need any change, but > >> now that I've typed this, I realize it would only require additions to > >> the XML, which can always be done later, so > > > > Yes, that's exactly why I ended up using XML for this - originally I > > had just used virTypedParameters but felt XML would give us better > > future proofing. Esstentially any part of the domain XML <interface> > > that is related to the /backend/ of the device is fair game for us > > to include in the filterbinding XML. I just started with the minimal > > set of data, rather than try to wire up everything, so it is simpler. > > > > So in the future , will the <filterbinding> possibly have a "type" > attribute? Should we go there now or just leave it for the future? I didn't want to add 'type' to this, as we don't neccessarily care about the device type. eg we might add a "type" that specifies the firewall engine type instead. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
