Re: [PATCH v2 net-next] net/hsr: add protocol version to fill_info output

[Fernando Fernandez Mancera <fmancera@suse.de>]

On 9/24/25 1:21 PM, Ján Václav wrote:
> On Wed, Sep 24, 2025 at 2:06 AM Jakub Kicinski <kuba@kernel.org> wrote:
>>
>> On Mon, 22 Sep 2025 11:37:45 +0200 Jan Vaclav wrote:
>>>        if (hsr->prot_version == PRP_V1)
>>>                proto = HSR_PROTOCOL_PRP;
>>> +     if (nla_put_u8(skb, IFLA_HSR_VERSION, hsr->prot_version))
>>> +             goto nla_put_failure;
>>
>> Looks like configuration path does not allow setting version if proto
>> is PRP. Should we add an else before the if? since previous if is
>> checking for PRP already
>>
> 
> The way HSR configuration is currently handled seems very confusing to
> me, because it allows setting the protocol version, but for PRP_V1
> only as a byproduct of setting the protocol to PRP. If you configure
> an interface with (proto = PRP, version = PRP_V1), it will fail, which
> seems wrong to me, considering this is the end result of configuring
> only with proto = PRP anyways.
> 

IMO, that is a good point.

> I think the best solution would be to introduce another change that
> allows explicitly setting the version to PRP_V1 if the protocol is set
> to PRP.
> 

I think it would be nice to unify the logic inside the else statement 
when parsing IFLA_HSR_VERSION and the later check for HSR_PROTOCOL_PRP. 
It could be simplified while supporting PRP_V1 explicitly set when PRP 
protocol is set.

Which also makes me wonder, should the enum hsr_version be exposed as 
UAPI? Currently it is under include/linux/if_hsr.h. But then, the naming 
should be something like "HSR_VERSION_HSR_0" or similar.