From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net RESEND] udp: restrict offloads to one namespace Date: Sun, 10 Jan 2016 17:28:41 -0500 (EST) Message-ID: <20160110.172841.1484098968226039838.davem@davemloft.net> References: <1452173319-13610-1-git-send-email-hannes@stressinduktion.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, tom@herbertland.com, edumazet@google.com To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:58640 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757589AbcAJW2o (ORCPT ); Sun, 10 Jan 2016 17:28:44 -0500 In-Reply-To: <1452173319-13610-1-git-send-email-hannes@stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Hannes Frederic Sowa Date: Thu, 7 Jan 2016 14:28:39 +0100 > udp tunnel offloads tend to aggregate datagrams based on inner > headers. gro engine gets notified by tunnel implementations about > possible offloads. The match is solely based on the port number. > > Imagine a tunnel bound to port 53, the offloading will look into all > DNS packets and tries to aggregate them based on the inner data found > within. This could lead to data corruption and malformed DNS packets. > > While this patch minimizes the problem and helps an administrator to find > the issue by querying ip tunnel/fou, a better way would be to match on > the specific destination ip address so if a user space socket is bound > to the same address it will conflict. > > Cc: Tom Herbert > Cc: Eric Dumazet > Signed-off-by: Hannes Frederic Sowa Applied, thanks Hannes.