Re: [PATCH v2] net: core: SIOCADDMULTI/SIOCDELMULTI distinguish between uc and mc

This doesn't seem appropriate at all.  If anything UC addresses
should be blocked and the Intel driver change reverted.  We have
a well defined way to add secondary UC addresses and the MC interfaces
are not it.

As I understand by ‘well defined way’ you mean macvlan feature. But macvlan 
is more virtualisation thing where an additional netdevice is created and for each
skb passed to linux stack hash_lookup is made to find a netdevice to which this
skb belongs to based on mac_dst. In case if someone want to have a network
protocol on top of physical layer (AF_PACKET) where NIC should allow several uc
mac addr without enabling promiscuous mode i am not sure that for this simple
task macvlan is needed.

Furthermore, even if this was appropriate, "fixing" this only for
ethernet is definitely not appropriate.  The fix would need to be able
to handle any address type.  Having a generic interface work
inconsistently for one link type vs. another is a non-starter.

Maybe overusing multicast api isn’t the best choice for this purpose, but i noticed
that it is already overused by i40 for the same purpose, that is why i suggested
this diff. Anyway i can add separate ioctls for add/del secondary uc, if this is worth it.