From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schultz Subject: Re: [PATCH 1/1] gtp: support SGSN-side tunnels Date: Mon, 13 Feb 2017 12:52:09 +0100 (CET) Message-ID: <1384904207.69904.1486986729381.JavaMail.zimbra@tpip.net> References: <20170203091231.10142-1-jonas@southpole.se> <1107124975.65949.1486977919253.JavaMail.zimbra@tpip.net> <20170213111640.GA1458@salvia> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Jonas Bonn , laforge , netdev To: pablo Return-path: Received: from mail.tpip.net ([92.43.49.48]:34817 "EHLO mail.tpip.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751652AbdBMLwM (ORCPT ); Mon, 13 Feb 2017 06:52:12 -0500 In-Reply-To: <20170213111640.GA1458@salvia> Sender: netdev-owner@vger.kernel.org List-ID: Hi, ----- On Feb 13, 2017, at 12:16 PM, pablo pablo@netfilter.org wrote: > On Mon, Feb 13, 2017 at 10:25:19AM +0100, Andreas Schultz wrote: >> Hi, >> >> I'm a bit late to comment, but maybe you can consider an additional >> change for v2... >> >> ----- On Feb 3, 2017, at 10:12 AM, Jonas Bonn jonas@southpole.se wrote: >> >> > The GTP-tunnel driver is explicitly GGSN-side as it searches for PDP >> > contexts based on the incoming packets _destination_ address. If we >> > want to write an SGSN, then we want to be idenityfing PDP contexts >> > based on _source_ address. >> > >> > This patch adds a "flags" argument at GTP-link creation time to specify >> > whether we are on the GGSN or SGSN side of the tunnel; this flag is then >> > used to determine which part of the IP packet to use in determining >> > the PDP context. >> > >> > Signed-off-by: Jonas Bonn >> > --- >> > >> > drivers/net/gtp.c | 43 ++++++++++++++++++++++++++++++++----------- >> > include/uapi/linux/gtp.h | 2 +- >> > include/uapi/linux/if_link.h | 5 +++++ >> > 3 files changed, 38 insertions(+), 12 deletions(-) >> > >> > diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c >> > index 50349a9..1bbac69 100644 >> > --- a/drivers/net/gtp.c >> > +++ b/drivers/net/gtp.c >> > @@ -72,6 +72,7 @@ struct gtp_dev { >> > struct net *net; >> > struct net_device *dev; >> > >> > + unsigned int flags; >> >> This should IMHO not go into the gtp_dev, the right place >> is the PDP context. > > So you want to allow mixed configurations where some PDP ctx may be in > SGSN mode while others in GGSN. > > This doesn't make any sense to me. On top of this, don't forget this > is just for testing, so I don't see any valid usecase for such a fine > grain thing. You are right, running such a configuration does not make sense. However, when I wrote this the PDP context looked like the most sensible palace to me. Anyhow, thinking about this again, I think that integrating that flag in a rewrite of the validation logic in the Rx path make more sense. Currently we validate the MS as soon as we have found the PDP context. This should be delayed a bit and the validation should happen after pulling the GTP header and right before injecting the payload into the net device. The flag would then indeed go into the gtp_dev. Andreas