Re: [PATCH net-next 0/3] net: vlan: fix bridge binding behavior and add selftests

[Sevinj Aghayeva]

(Resending this because the first email was rejected due to being in HTML.)


On Sat, Jul 30, 2022 at 12:46 PM Sevinj Aghayeva
<sevinj.aghayeva@xxxxxxxxx> wrote:
>
>
>
> On Sat, Jul 30, 2022 at 12:22 PM Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> wrote:
>>
>> On 7/30/22 19:03, Sevinj Aghayeva wrote:
>> > When bridge binding is enabled for a vlan interface, it is expected
>> > that the link state of the vlan interface will track the subset of the
>> > ports that are also members of the corresponding vlan, rather than
>> > that of all ports.
>> >
>> > Currently, this feature works as expected when a vlan interface is
>> > created with bridge binding enabled:
>> >
>> >    ip link add link br name vlan10 type vlan id 10 protocol 802.1q \
>> >          bridge_binding on
>> >
>> > However, the feature does not work when a vlan interface is created
>> > with bridge binding disabled, and then enabled later:
>> >
>> >    ip link add link br name vlan10 type vlan id 10 protocol 802.1q \
>> >          bridge_binding off
>> >    ip link set vlan10 type vlan bridge_binding on
>> >
>> > After these two commands, the link state of the vlan interface
>> > continues to track that of all ports, which is inconsistent and
>> > confusing to users. This series fixes this bug and introduces two
>> > tests for the valid behavior.
>> >
>> > Sevinj Aghayeva (3):
>> >    net: bridge: export br_vlan_upper_change
>> >    net: 8021q: fix bridge binding behavior for vlan interfaces
>> >    selftests: net: tests for bridge binding behavior
>> >
>> >   include/linux/if_bridge.h                     |   9 ++
>> >   net/8021q/vlan.h                              |   2 +-
>> >   net/8021q/vlan_dev.c                          |  21 ++-
>> >   net/bridge/br_vlan.c                          |   7 +-
>> >   tools/testing/selftests/net/Makefile          |   1 +
>> >   .../selftests/net/bridge_vlan_binding_test.sh | 143 ++++++++++++++++++
>> >   6 files changed, 176 insertions(+), 7 deletions(-)
>> >   create mode 100755 tools/testing/selftests/net/bridge_vlan_binding_test.sh
>> >
>>
>> Hmm.. I don't like this and don't think this bridge function should be
>> exported at all.
>>
>> Calling bridge state changing functions from 8021q module is not the
>> proper way to solve this. The problem is that the bridge doesn't know
>> that the state has changed, so you can process NETDEV_CHANGE events and
>> check for the bridge vlan which got its state changed and react based on
>> it. I haven't checked in detail, but I think it should be doable. So all
>> the logic is kept inside the bridge.
>
>
> Hi Nik,
>
> Can please elaborate on where I should process NETDEV_CHANGE events? I'm doing this as part of outreachy project and this is my first kernel task, so I don't know the bridging code that well.
>
> Thanks!
>
>>
>>
>> Cheers,
>>   Nik
>
>
>
> --
>
> Sevinj.Aghayeva



-- 

Sevinj.Aghayeva