Linux Ethernet Bridging - Aug 2022 - [Bridge] [PATCH v5 net-next 6/6] selftests: forwarding: add test of MAC-Auth Bypass to locked port tests

On 2022-08-29 13:32, Ido Schimmel wrote:
>> The final decision on this rests with you I would say.
> 
> If the requirement for this feature (with or without MAB) is to work
> with dynamic entries (which is not what is currently implemented in the
> selftests), then learning needs to be enabled for the sole reason of
> refreshing the dynamic entries added by user space. That is, updating
> 'fdb->updated' with current jiffies value.
> 
> So, is this the requirement? I checked the hostapd fork you posted some
> time ago and I get the impression that the answer is yes [1], but I 
> want
> to verify I'm not missing something.
> 
> [1] 
>
https://github.com/westermo/hostapd/commit/95dc96f9e89131b2319f5eae8ae7ac99868b7cd0#diff-338b6fad34b4bdb015d7d96930974bd96796b754257473b6c91527789656d6edR11
> 
> 
I cannot say that it is a requirement with respect to the bridge 
implementation, but it is with the driver implementation. But you are 
right that it is to be used with dynamic entries.
>> > # ip link set dev swp1 up
>> > # ip link set dev swp2 up
>> > # ip link set dev br0 up
>> >
>> > 2. Assuming h1 behind swp1 was authorized using 802.1X:
>> >
>> > # bridge fdb replace $H1_MAC dev swp1 master dynamic
>> 
>> With the new MAB flag 'replace' is not needed when MAB is not
enabled.
> 
> Yes, but replace works in both cases.
> 
Yes, of course.
>> 
>> >
>> > 3. Assuming 802.1X authentication failed for h2 behind swp2,
enable MAB:
>> >
>> > # bridge link set dev swp2 mab on
>> >
>> > 4. Assuming $H2_MAC is in our allow list:
>> >
>> > # bridge fdb replace $H2_MAC dev swp2 master dynamic
>> >
>> > Learning is on in order to refresh the dynamic entries that user
space
>> > installed.
>> 
>> Yes, port association is needed for those reasons. :-)
> 
> Given that the current tests use "static" entries that cannot
age, is
> there a reason to have "learning on"?
> 
Port association is needed for MAB to work at all on mv88e6xxx, but for 
802.1X port association is only needed for dynamic ATU entries.
>> 
>> >
>> > (*) Need to add support for this option in iproute2. Already
exposed
>> > over netlink (see 'IFLA_BR_MULTI_BOOLOPT').
>> 
>> Should I do that in this patch set?
> 
> No, I'm saying that this option is already exposed over netlink, but
> missing iproute2 support. No kernel changes needed.
Oh yes, I meant in the iproute2 accompanying patch set to this one?

On Mon, Aug 29, 2022 at 02:04:42PM +0200, netdev at kapio-technology.com
wrote:
> On 2022-08-29 13:32, Ido Schimmel wrote:
> > > The final decision on this rests with you I would say.
> > 
> > If the requirement for this feature (with or without MAB) is to work
> > with dynamic entries (which is not what is currently implemented in
the
> > selftests), then learning needs to be enabled for the sole reason of
> > refreshing the dynamic entries added by user space. That is, updating
> > 'fdb->updated' with current jiffies value.
> > 
> > So, is this the requirement? I checked the hostapd fork you posted
some
> > time ago and I get the impression that the answer is yes [1], but I
want
> > to verify I'm not missing something.
> > 
> > [1]
https://github.com/westermo/hostapd/commit/95dc96f9e89131b2319f5eae8ae7ac99868b7cd0#diff-338b6fad34b4bdb015d7d96930974bd96796b754257473b6c91527789656d6edR11
> > 
> > 
> 
> I cannot say that it is a requirement with respect to the bridge
> implementation, but it is with the driver implementation. But you are right
> that it is to be used with dynamic entries.
OK, so it's a requirement for both since we need both data paths to act
the same.

[...]
> Port association is needed for MAB to work at all on mv88e6xxx, but for
> 802.1X port association is only needed for dynamic ATU entries.
Ageing of dynamic entries in the bridge requires learning to be on as
well, but in these test cases you are only using static entries and
there is no reason to enable learning in the bridge for that. I prefer
not to leak this mv88e6xxx implementation detail to user space and
instead have the driver enable port association based on whether
"learning" or "mab" is on.

[...]
> Oh yes, I meant in the iproute2 accompanying patch set to this one?
You can send it as a standalone patch to iproute2-next:
https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git

Subject prefix should be "[PATCH iproute2-next]". See this commit for
reference:
https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=d2eecb9d1d4823a04431debd990824a5d610bfcf