From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: Advice needed on IP-over-InfiniBand driver Date: Thu, 30 Sep 2004 11:41:07 -0700 Sender: openib-general-bounces@openib.org Message-ID: <521xgj1tx8.fsf@topspin.com> References: <52fz5esxx6.fsf@topspin.com> <20040919140133.60ea3fb3.davem@davemloft.net> <52r7onc8ev.fsf@topspin.com> <20040927215244.697aaa02.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@oss.sgi.com, openib-general@openib.org Return-path: To: "David S. Miller" In-Reply-To: <20040927215244.697aaa02.davem@davemloft.net> (David S. Miller's message of "Mon, 27 Sep 2004 21:52:44 -0700") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: openib-general-bounces@openib.org List-Id: netdev.vger.kernel.org David> I think you might learn something by having a look at what David> net/atm/clip.c is doing, it creates it's own neighbour David> layer for CLIP ATM neighbours. It is in a similar boat to David> your IPoIB stuff. Thanks, this suggestion was very helpful. I think I'm making progress. Now I know my next question :) CLIP ATM is a little different from IPoIB in that it completely replaces the ARP layer with its own ARP daemon. For IPoIB I don't want to reinvent the ARP and ND code -- I just want to add a secondary lookup after the response comes back. I think I have an idea of how to do that and then stash the information in the struct neighbour, so that my hard_start_xmit method can get it from skb->dst (ala clip.c). However, it seems that broadcast ARP packets have skb->dst == NULL. Is it safe for me to assume that packets with skb->dst == NULL are broadcast packets? Will multicast packets have a non-NULL dst? Thanks, Roland