nwfilter issue with new ebtables

[Laine Stump]

On 11/16/20 2:01 AM, Christian Ehrhardt wrote:
> Hi,
> I have last week discussed breakage in nwfilter usage on IRC
>
>     <filterref filter='clean-traffic'>
>       <parameter name='CTRL_IP_LEARNING' value='dhcp'/>
>     </filterref>
> virsh start <guest>
>    error: Failed to start domain <guest>
>    error: internal error: applyDHCPOnlyRules failed - spoofing not protect
>
> With debug in the logs enabled I got confirmation by Daniel (thanks!)
> that the command sequence libvirt issued looked kind of "normal".
>
> Hereby I wanted to let you know that some further debugging identified
> a part of the sequence that libvirt issues as being broken in recent
> ebtables versions.
>
>    # ebtables --concurrent -t nat -N testrule3
>    # ebtables --concurrent -t nat -E testrule3 testrule3-renamed
>    ebtables v1.8.6 (nf_tables): Chain 'testrule3' doesn't exists


So you're saying you can just run those two commands together and always 
get the error? (assuming that "testrule3 and testrule3-renamed don't 
exist beforehand)


 From your description it sounds like maybe the error doesn't occur when 
there is a pause between the two commands - is that right, or am I 
assuming too much?


I tried the above commands (well, I put the two commands together on a 
single line separated by ";") on a Fedora 33 system and a RHEL 8.3.0 
system, and both of them completed successfully.


This is the fedora ebtables -V: ebtables v2.0.11 (legacy) (December 2011)


And this is the ebtables -V on RHEL 8.3.0: ebtables 1.8.4 (nf_tables)


(I don't have any idea how the version's relate to each other for legacy 
ebtables vs. the nf_tables version)


> This led to upstream ebtables bug [1] - for now just FYI in case you
> want/need to subscribe for your own tracking.
>
> [1]: https://bugzilla.netfilter.org/show_bug.cgi?id=1481
>