From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net ([184.105.139.130]:44230 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751732AbeBZRLa (ORCPT ); Mon, 26 Feb 2018 12:11:30 -0500 Date: Mon, 26 Feb 2018 12:11:27 -0500 (EST) Message-Id: <20180226.121127.2237252602192340288.davem@davemloft.net> To: sd@queasysnail.net Cc: dsahern@gmail.com, netdev@vger.kernel.org Subject: Re: [PATCH net-next] ipv6: allow userspace to add IFA_F_OPTIMISTIC addresses From: David Miller In-Reply-To: <20180226165619.GA10603@bistromath.localdomain> References: <20180226154132.GA7083@bistromath.localdomain> <20180226.105711.81890471902412308.davem@davemloft.net> <20180226165619.GA10603@bistromath.localdomain> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org List-ID: From: Sabrina Dubroca Date: Mon, 26 Feb 2018 17:56:19 +0100 > 2018-02-26, 10:57:11 -0500, David Miller wrote: >> Userland is now repsonsible for implementing correct behavior when it >> takes over this task, and therefore the kernel has no say in the >> matter of proper ipv6 neighbor discovery and addrconf behavior. > > As an aside, that's also the case whenever userland uses packet > sockets. When you use packet sockets, all bets are off and it is clearly the case that the user gets to keep the broken pieces when things go wrong. That's completely different to this case, which is a bonfide explicit allowance for userspace to take over these fundamental protocol tasks from the kernel. So please do not use packet sockets as an example of a similar situation.