From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net-next v4 1/2] New kernel function to get IP overhead
 on a socket.
Date: Mon, 03 Apr 2017 13:30:40 -0700 (PDT)
Message-ID: <20170403.133040.2079781719239791612.davem@davemloft.net>
References: <alpine.DEB.2.11.1703231809410.19388@vera100.eng.brocade.com>
        <14517769-bf88-a541-4948-1504a6d7acac@katalix.com>
        <alpine.DEB.2.11.1704031316390.24947@vera100.eng.brocade.com>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: jchapman@katalix.com, kleptog@svana.org, nprachan@brocade.com,
        rshearma@brocade.com, stephen@networkplumber.org,
        sdietric@brocade.com, ciwillia@brocade.com, lboccass@brocade.com,
        dfawcus@brocade.com, bhong@brocade.com, jblunck@brocade.com,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
To: parameswaran.r7@gmail.com
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <alpine.DEB.2.11.1704031316390.24947@vera100.eng.brocade.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

From: "R. Parameswaran" <parameswaran.r7@gmail.com>
Date: Mon, 3 Apr 2017 13:28:11 -0700 (PDT)

> Can I take this to mean that we do need to factor in IP options in 
> the L2TP device MTU setup (i.e approach in the posted patch is okay)? 
> 
> If yes, please let me know if I can keep the socket IP option overhead 
> calculations in a generic function, or it would be better to move it back into 
> L2TP code? 

If the user creates and maintains this UDP socket, then yes we have to
account for potential IP options.