From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net] net: Avoid receiving packets with an l3mdev on unbound UDP sockets Date: Thu, 26 Jan 2017 11:12:50 -0700 Message-ID: <52c73e8e-56e8-efe4-49df-e189f35e3017@cumulusnetworks.com> References: <1485453744-5120-1-git-send-email-rshearma@brocade.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Robert Shearman , davem@davemloft.net Return-path: Received: from mail-pf0-f178.google.com ([209.85.192.178]:36189 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753616AbdAZSNU (ORCPT ); Thu, 26 Jan 2017 13:13:20 -0500 Received: by mail-pf0-f178.google.com with SMTP id 189so67029753pfu.3 for ; Thu, 26 Jan 2017 10:12:52 -0800 (PST) In-Reply-To: <1485453744-5120-1-git-send-email-rshearma@brocade.com> Sender: netdev-owner@vger.kernel.org List-ID: On 1/26/17 11:02 AM, Robert Shearman wrote: > Packets arriving in a VRF currently are delivered to UDP sockets that > aren't bound to any interface. TCP defaults to not delivering packets > arriving in a VRF to unbound sockets. IP route lookup and socket > transmit both assume that unbound means using the default table and > UDP applications that haven't been changed to be aware of VRFs may not > function correctly in this case since they may not be able to handle > overlapping IP address ranges, or be able to send packets back to the > original sender if required. > > So add a sysctl, udp_l3mdev_accept, to control this behaviour with it > being analgous to the existing tcp_l3mdev_accept, namely to allow a > process to have a VRF-global listen socket. Have this default to off > as this is the behaviour that users will expect, given that there is > no explicit mechanism to set unmodified VRF-unaware application into a > default VRF. > > Signed-off-by: Robert Shearman > --- > I've targetted this for the net tree because I believe the expected > behaviour is different enough from the current behaviour to be > considered a bug. However, this should also apply to the net-next tree > as-is if this not deemed a bug. > I have almost this exact patch in my tree and I have it marked as not working so 1 or more test cases is failing. So, really this is just a note that I need to test this and need some time to get to it.