Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754019Ab3ETGsU (ORCPT ); Mon, 20 May 2013 02:48:20 -0400 Received: from mail-bk0-f52.google.com ([209.85.214.52]:47545 "EHLO mail-bk0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751611Ab3ETGsT (ORCPT ); Mon, 20 May 2013 02:48:19 -0400 Date: Mon, 20 May 2013 08:50:58 +0200 From: Alexander Aring To: David Hauweele Cc: Alexander Smirnov , Dmitry Eremin-Solenikov , "David S. Miller" , linux-zigbee-devel@lists.sourceforge.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] 6lowpan: Fix fragmentation with link-local compressed addresses Message-ID: <20130520065057.GA1393@x61s.Speedport_W_921V_1_21_000> References: <1368987211-19826-1-git-send-email-david@hauweele.net> <20130519195809.GA3237@x61s.Speedport_W_921V_1_21_000> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2447 Lines: 83 Hi David, I will try to figure out why link-layer address doesn't work on my setup. On Mon, May 20, 2013 at 12:14:48AM +0200, David Hauweele wrote: > Hello, > > There is a patch which fixes link-local address uncompression: > > http://permalink.gmane.org/gmane.linux.network.zigbee.devel/1717 > > I came across a similar solution but didn't submit it as another patch > already existed. > This patch instead focus on fragmented packet with link-local address > compression, > which is related but a different bug. > > 2013/5/19 Alexander Aring : > > Hi David, > > > > can you use a link-layer address on the current net-next kernel? > > > > I am asking because I can't use a link-layer address currently. > > Your patch doesn't help to solve my problem with link-layer addresses. > > > > > > To your patch: > > > > We get the link-layer addresses from skb not from the allocated > > frame->skb. > > > > Here is the code: > > > > _saddr = mac_cb(skb)->sa.hwaddr; > > _daddr = mac_cb(skb)->da.hwaddr; > > > > Here is skb != frame->skb so we don't need to copy it to frame->skb->cb > > because we already the link-layer addresses from skb->cb. > > > > Is there another place in the code where we get the link-layer addresses > > from allocated "frame" structure? > > frame->skb is used to reassemble the 6lowpan packet when new fragments > are received. > This is the 'fragments assembling' switch at the beginning of > lowpan_process_data(). > It will reassemble fragments until the packet is successfully reassembled. > Once it is, skb is replaced: > > dev_kfree_skb(skb); > skb = frame->skb; > kfree(frame); > ah ok. > And the process continues as with other 6lowpan packets. > > In particular: > > _saddr = mac_cb(skb)->sa.hwaddr; > _daddr = mac_cb(skb)->da.hwaddr; > > Several lines later there are: > > err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix, > lowpan_unc_llconf[tmp], skb->data); > err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix, > lowpan_unc_llconf[tmp], skb->data); I think you mean uncompress and compress here. > > These two lines should use _saddr/_daddr instead of skb->data, which I agree with that. Regards Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/