From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 13 Mar 2009 22:39:32 -0700 From: Stephen Hemminger Message-ID: <20090313223932.50ebbd88@nehalam> In-Reply-To: <20090313183303.GF3436@psychotron.englab.brq.redhat.com> References: <20090313183303.GF3436@psychotron.englab.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Bridge] [PATCH] bonding: allow bond in mode balance-alb to work properly in bridge List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jiri Pirko Cc: fubar@us.ibm.com, netdev@vger.kernel.org, bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, bonding-devel@lists.sourceforge.net, jgarzik@pobox.com, davem@davemloft.net On Fri, 13 Mar 2009 19:33:04 +0100 Jiri Pirko wrote: > Hi all. > > This is only a draft of patch to consult. I'm aware that it should be divided > into multiple patches. I want to know opinion from you folks. > > The problem is described in following bugzilla: > https://bugzilla.redhat.com/show_bug.cgi?id=487763 > > Basically here's what's going on. In every mode, bonding interface uses the same > mac address for all enslaved devices. Except for mode balance-alb. When you put > this kind of bond device into a bridge it will only add one of mac adresses into > a hash list of mac addresses, say X. This mac address is marked as local. But > this bonding interface also has mac address Y. Now then packet arrives with > destination address Y, this address is not marked as local and the packed looks > like it needs to be forwarded. This packet is then lost which is wrong. > > Notice that interfaces can be added and removed from bond while it is in bridge. > Therefore I introduce another function pointer in struct net_device_ops - > ndo_check_mac_address. This function when it's implemented should check passed > mac address against the one set in device. I'm using this in bonding driver when > the bond is in mode balance-alb to walk thru all slaves and checking if any of > them equals passed address. > > Then in bridge function br_handle_frame_finish() I'm using ndo_check_mac_address > to recognize the destination mac address as local. > > Please look at this and tell me what you think about it. > > Thanks > > Jirka > A better and more general way to do this have the dev_set_mac_address function check the return of the notifier and unwind. Then any protocol can easily prevent address from changing.