From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Herbert Subject: Re: FOU RX interface? Date: Thu, 2 Oct 2014 07:44:55 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Network Development , "David S. Miller" To: Andy Lutomirski Return-path: Received: from mail-ie0-f177.google.com ([209.85.223.177]:34496 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507AbaJBOo4 (ORCPT ); Thu, 2 Oct 2014 10:44:56 -0400 Received: by mail-ie0-f177.google.com with SMTP id rd18so2635188iec.22 for ; Thu, 02 Oct 2014 07:44:56 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Oct 1, 2014 at 10:14 PM, Andy Lutomirski wrote: > Hi- > > Sorry for the lack of proper threading here -- I lost the original message. > > If I'm understanding the FOU use case correctly, if I set up a FOU > tunnel tun0 that is encapsulated in UDP on eth0, then tun0 packets > will be transmitted on tun0, but incoming packets will show up on eth0 > when they're reinjected after stripping the FOU header. > Incoming FOU packets will still land on the tunnel interface. In FOU RX the UDP packet is removed and logically re-injected into the stack-- at this point the packet is IPIP in IP (or sit, GRE) so appropriate tunnel protocol processing occurs. > Is this right? I think that, without a way to reinject the received > packets on the tunnel interface, using FOU will be annoying. For > example, writing firewall rules might be tricky. And programs that > use packet sockets or SO_BINDTODEVICE could have a hard time being > configured such that they notice the received packets. > I believe it should work. > Also, is it even possible to assign a FOU tunnel to a different > network namespace than the device that's being tunneled over? How > will the received packets end up in the right netns? > Anything you can do with IP tunnels, you should be able to with FOU enabled IP tunnels. FOU is transparent to IP tunnels on RX. > --Andy