Subject: Re: [RFC:] struct net_device_ops: Add function pointer to fill device specific ndisc information

From: Stephan Gatzka <[email-masked]>
Date: Mon, 21 Jan 2013 07:25:33 +0100

> We could have multiple "net_device"s per single physical
> interface at the same time, then.

Of course, but I would avoid it if it's not necessary. What's the 
problem with introducing a function pointer in struct net_device or 
struct net_device_ops?

>
> Multicast is a big issue.  Because IPv6 is fan of
> multicast, and it uses link-local multicast as its
> core infrastructure.  Without infrastructure to
> support it, I'm not going to agree.

firewire net supports multicast and we use it very often. My patch to 
support IPv6 does not change it. In fact, because I can communicate via 
IPv6  between two firewire nodes, multicast _is_ running. The driver 
does not do lot's of special things with multicast packets. But 
multicast packets are recognized because they have to be sent somehow 
different (GASP).

>
> And, firewire driver does not seem to support zerocopy
> (fragmented skb) support.  It help performance.

O.k., good point. I will have a look into that. But I suggest to not mix 
up this issue with the IPv6 over firewire enhancement. That should be a 
separate patch.

Stephan