From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH 2/2] ipv4: Change rt->rt_iif encoding.
Date: Mon, 23 Jul 2012 16:14:46 -0700 (PDT)
Message-ID: <20120723.161446.36265037346365173.davem@davemloft.net>
References: <20120723.152220.822947775372843073.davem@davemloft.net>
	<alpine.LFD.2.00.1207240157120.2404@ja.ssi.bg>
	<20120723.160541.184307938805782289.davem@davemloft.net>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: netdev@vger.kernel.org
To: ja@ssi.bg
Return-path: <netdev-owner@vger.kernel.org>
Received: from shards.monkeyblade.net ([149.20.54.216]:50514 "EHLO
	shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752749Ab2GWXOr (ORCPT
	<rfc822;netdev@vger.kernel.org>); Mon, 23 Jul 2012 19:14:47 -0400
In-Reply-To: <20120723.160541.184307938805782289.davem@davemloft.net>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

From: David Miller <davem@davemloft.net>
Date: Mon, 23 Jul 2012 16:05:41 -0700 (PDT)

> From: Julian Anastasov <ja@ssi.bg>
> Date: Tue, 24 Jul 2012 02:11:38 +0300 (EEST)
> 
>> skb_iif: ifindex of device we arrived on
>> 
>> 	If it has hidden semantic may be we can make this
>> comment more specific, does it survive some loops?
> 
> Strangely I hadn't noticed this, and after the email I just sent
> out I was going to look into adding such a value :-)
> 
> Great!
> 
> I'll respin my patches to use that thing, thanks Julian.

Hmmm, the problem is that when we decapsulate VLAN devices, we're left
with the parent device's index in skb->skb_iif.

That's what all of that "orig_dev" logic in __netif_receive_skb() is
all about.  The skb->dev is rewritten by vlan_do_receive() for that
case.

I wonder if we should just get rid of all of that orig_dev logic and
simply update skb->skb_iif every time we hit the code starting at
label "another_round"

I'll keep looking into this.