From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5824DC2D0B1 for ; Tue, 4 Feb 2020 11:39:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32F7020730 for ; Tue, 4 Feb 2020 11:39:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727234AbgBDLjn (ORCPT ); Tue, 4 Feb 2020 06:39:43 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:42138 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727004AbgBDLjm (ORCPT ); Tue, 4 Feb 2020 06:39:42 -0500 Received: from localhost (unknown [IPv6:2001:982:756:1:57a7:3bfd:5e85:defb]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 7D331133E904C; Tue, 4 Feb 2020 03:39:41 -0800 (PST) Date: Tue, 04 Feb 2020 12:39:40 +0100 (CET) Message-Id: <20200204.123940.1811238158618411613.davem@davemloft.net> To: ridge.kennedy@alliedtelesis.co.nz Cc: netdev@vger.kernel.org, gnault@redhat.com, tparkin@katalix.com, jchapman@katalix.com Subject: Re: [PATCH v2 net] l2tp: Allow duplicate session creation with UDP From: David Miller In-Reply-To: <20200203232400.28981-1-ridge.kennedy@alliedtelesis.co.nz> References: <20200203232400.28981-1-ridge.kennedy@alliedtelesis.co.nz> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 04 Feb 2020 03:39:42 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Ridge Kennedy Date: Tue, 4 Feb 2020 12:24:00 +1300 > In the past it was possible to create multiple L2TPv3 sessions with the > same session id as long as the sessions belonged to different tunnels. > The resulting sessions had issues when used with IP encapsulated tunnels, > but worked fine with UDP encapsulated ones. Some applications began to > rely on this behaviour to avoid having to negotiate unique session ids. > > Some time ago a change was made to require session ids to be unique across > all tunnels, breaking the applications making use of this "feature". > > This change relaxes the duplicate session id check to allow duplicates > if both of the colliding sessions belong to UDP encapsulated tunnels. > > Fixes: dbdbc73b4478 ("l2tp: fix duplicate session creation") > Signed-off-by: Ridge Kennedy Applied and queued up for -stable, thank you.