[openib-general] Re: [PATCH] IPoIB: Set hardware header on packet receive

[Hal Rosenstock]

On Mon, 2005-03-28 at 11:43, Roland Dreier wrote:
>     Hal> I think it depends on how symmetric you want to make the
>     Hal> receive side and what information you want to pass up.
> 
>     Hal> The IPoIB encapsulation actually is needed, otherwise the
>     Hal> protocol type cannot be determined.
> 
> So we should set mac.raw before the skb_pull rather than where you put
> the assignment?

Yes. I think that is better and more correct. I am experimenting with
this now.

>     Hal> The DGID is also probably needed as it addresses the
>     Hal> following comment in ipoib_ib.c:
> 
>     Hal> /* XXX get correct PACKET_type here */
>     skb-> pkt_type = PACKET_HOST;
> 
>     Hal> Checking the incoming DGID is the only good way to determine
>     Hal> whether the incoming packet is unicast, broadcast, or
>     Hal> multicast.
> 
> Yes.  I haven't added any code there because just setting PACKET_HOST
> all the time doesn't seem to affect anything.

I was wondering about this myself as to whether this matters or not.
Other drivers determine this from the destination MAC address. Does it
affect the incoming delivery if more than one process is receiving an IP
broadcast or multicast ? I didn't chase it all the way down in the Linux
kernel. Do you know ?

-- Hal