[libvirt] [tck PATCH 5/4] nwfilter: account for more leading 0's in MAC addresses in ebtables output

[Daniel P. Berrangé]

On Mon, Feb 11, 2019 at 02:56:31PM +0000, Daniel P. Berrangé wrote:
> On Mon, Feb 11, 2019 at 09:51:09AM -0500, Laine Stump wrote:
> > On 2/11/19 6:11 AM, Daniel P. Berrangé wrote:
> > > On Mon, Feb 11, 2019 at 06:07:40AM -0500, Laine Stump wrote:
> > > > On Mon, Feb 11, 2019, 5:50 AM Daniel P. Berrangé <berrange at redhat.com>
> > > > wrote:
> > > > 
> > > > > On Sat, Feb 09, 2019 at 02:03:05PM -0500, Laine Stump wrote:
> > > > > > Since this test (050-apply-verify-host.t), we can't use a regexp in
> > > > > > the string to be compared. The fix method that leads to the least
> > > > > > changes is to use sed to remove potential leading 0's.
> > > > > > 
> > > > > > Signed-off-by: Laine Stump <laine at laine.org>
> > > > > > ---
> > > > > > 
> > > > > > (These changes fix *almost* all failures in
> > > > > > nwfilter/050-apply-verify-host.t on RHEL8. The rest look like they
> > > > > > might be legitimate problems with ebtables and IPv6)
> > > > > Interesting, I swear I have previously got that test to succeed so
> > > > > wonder what's changed since then !
> > > > > 
> > > > I figured it out yesterday evening but haven't gotten a chance to post it
> > > > yet. I was being alarmist - its not a behavioral difference, but just a
> > > > difference in how ipv6 addresses are formatted. The original ebtables
> > > > reports ipv6 addresses with a netmask (/ffff:ffff:ffff:ffff:8000::) while
> > > > the iptables-ebtables package that RHRL8 is now using reports it with a
> > > > prefix (/65). They probably hadn't switched packages yet the last time you
> > > > ran the test. I have a patch that modifies the expected output (and uses
> > > > sed to modify the output from 'older' hosts, similar to what you had done
> > > > for RARP vs 0x8035) and will post it in a few hours, once I've had coffee
> > > > and tested on both types of host.
> > > IMHO that should be reported as a bug against ebtables. The output format
> > > of the new tools should be 100% identical tothe old tools. Changing from
> > > a netmask to a prefix is a significant semantic difference that will break
> > > too many uses.
> > 
> > 
> > I thought about that, but wasn't feeling that ambitious since it was Sunday.
> > If this is considered a bug, then changing the MAC address format from
> > %x:%x:%x:%x:%x:%x to %0x:%0x:%0x:%0x:%0x:%0x should also be considered a
> > bug.
> 
> Yes, I thought about that too. I think it would be worth raising that with
> the maintainers to validate this was intentional. I get the feeling they'll
> say that the old behaviour was a clear bug. If anything I'd probably ask
> them to fix the old impl to not skip leading zeros too. IMHO mac addrs
> should always be exactly the same length when printed.
> 
> > I'll still post a patch to remedy it in the tests, but won't push it (unless
> > you think that's worthwhile) and will file a bug instead.
> 
> Yep, lets at least wait & see what response we get to a bug report on this
> issue.

Upstream has now taken a patch which changes the old ip6tables tool
to print the prefix, instead of netmask too, so we need to take this
patch of yours to the TCK


Regards,
Daniel
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