Re: [RFC net-next v3 03/10] net: bridge: mrp: Add MRP interface used by netlink

[Nikolay Aleksandrov]

On 26/01/2020 15:28, Horatiu Vultur wrote:
> The 01/25/2020 20:16, Allan W. Nielsen wrote:
>> On 25.01.2020 16:20, Andrew Lunn wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>
>>> On Sat, Jan 25, 2020 at 12:37:26PM +0100, Horatiu Vultur wrote:
>>>> The 01/24/2020 18:43, Andrew Lunn wrote:
>>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>>>
>>>>>> br_mrp_flush - will flush the FDB.
>>>>>
>>>>> How does this differ from a normal bridge flush? I assume there is a
>>>>> way for user space to flush the bridge FDB.
>>>>
>>>> Hi,
>>>>
>>>> If I seen corectly the normal bridge flush will clear the entire FDB for
>>>> all the ports of the bridge. In this case it is require to clear FDB
>>>> entries only for the ring ports.
>>>
>>> Maybe it would be better to extend the current bridge netlink call to
>>> be able to pass an optional interface to be flushed?  I'm not sure it
>>> is a good idea to have two APIs doing very similar things.
>> I agree.
> I would look over this.
> 

There's already a way to flush FDBs per-port - IFLA_BRPORT_FLUSH.

>>
>> And when looking at this again, I start to think that we should have
>> extended the existing netlink interface with new commands, instead of
>> adding a generic netlink.
> We could do also that. The main reason why I have added a new generic
> netlink was that I thought it would be clearer what commands are for MRP
> configuration. But if you think that we should go forward by extending
> existing netlink interface, that is perfectly fine for me.
> 
>>
>> /Allan
>>
> 

I don't mind extending the current netlink interface but the bridge already has
a huge (the largest) set of options and each time we add a new option we have
to adjust RTNL_MAX_TYPE. If you do decide to go this way maybe look into nesting
all the MRP options under one master MRP element into the bridge options, example:
[IFLA_BR_MRP]
  [IFLA_BR_MRP_X]
  [IFLA_BR_MRP_Y]
  ...

To avoid increasing the stack usage and bumping the max rtnl type too much.

Cheers,
 Nik