Re: [PATCH RFC net-next v2 2/2] af_packet: Add port specific handling for HSR

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2026-03-13 10:22:28 [+0100], To Willem de Bruijn wrote:
> On 2026-03-12 17:43:36 [-0400], Willem de Bruijn wrote:
> > > Yes, this is RX. If I open packet socket, bind to hsr0, how do I filter
> > > for packets from one of the slaves?
> > 
> > I was thinking of attaching directly to the slave devices.
> 
> That could work. Let me see.

Halfway done. What we went down to is:

Send with header    -> eth0/ eth1 + SO_MARK for header + port 1/ 2
Send without header -> hsr0 + SO_MARK 1/2 port 1/ 2 
RX                  -> listen on eth0/ eth1

Now this compiles and I look into userland and am currently stuck with
the problem that it does not expect "two devices". It is not impossible
but…

> > > After some thinking and browsing through the packet code:
> > > The hsr stack creates hsrX. If it would create additionally hsrX_A and
> > > hsrX_B in order to be able to send and receive only on the relevant
> > > slave device then I wouldn't need the filters in packet code. That could
> > > work…
> > 
> > That's another option.
> 
> Okay. Let me add this as plan B then.

At this point I am considering this which would avoid having to use
hsr0+eth1 for one direction depending on whether I have to send with or
without the header. But this might lead to other problems such as ip
address and so on.
 
The suggested changes to af_packet, that remains a hard no?

Sebastian