From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f181.google.com ([74.125.82.181]:48455 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755914AbaHHJd7 (ORCPT ); Fri, 8 Aug 2014 05:33:59 -0400 Received: by mail-we0-f181.google.com with SMTP id k48so5431951wev.12 for ; Fri, 08 Aug 2014 02:33:58 -0700 (PDT) Date: Fri, 8 Aug 2014 11:33:56 +0200 From: Alexander Aring Message-ID: <20140808093353.GC20055@omega> References: <53E48D10.3090606@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <53E48D10.3090606@gmail.com> Sender: linux-wpan-owner@vger.kernel.org List-ID: Subject: Re: Regarding dev->addr_len To: Varka Bhadram Cc: linux-wpan - ML Hi Varka, On Fri, Aug 08, 2014 at 02:10:48PM +0530, Varka Bhadram wrote: > Hi Alex, > > I need some clarification regarding address length for the netdevice. > We are always setting up that to IEEE802154_ADDR_LEN [1]. > > If i receive a packet (RS: Router Solicitation) with short addressing mode, > it is discarding at higher layers. > > If the linux node receives the RS packet from TinyOS node its discarding > at [2] due to address length field. Here [2] we are getting *lladdr* as NULL. > yes, I said about some months ago to Martin that he should not use short addresses in 6lowpan because it's simply not working currently. > > Actually we have to update the dev->addr_len filed as per the packet info it received ..? > If you look at net/ipv6/ndisc.c code you will notice that when you change the addr_len of netdevice during runtime will end in an unexecpted behaviour. > How can we make it work..? > I already open a thread to related this question [0]. Please don't open a new one! David wrote something I need to answer him, but need to consider how I can describe the current behaviour in words. We can't just do own changes in net/ipv6/ndisc.c, only very very small changes and changes which don't brake the ethernet, etc... neighbor discovery. I have several ideas to deal with, some need a complete change of architecture to deal with short and extended addresses. Currently we have in dev_addr the extended address and the addr_len is a static value. And that's also what the neighbor discovery use from L2, the addr_len and dev_addr only. Okay, there are also the header_ops callbacks, I need to take a closer look into that to have some idea. - Alex [0] http://www.spinics.net/lists/netdev/msg291767.html