From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] tun: fix premature POLLOUT notification on tun devices Date: Mon, 13 Mar 2017 22:01:22 -0700 (PDT) Message-ID: <20170313.220122.1218068190297475298.davem@davemloft.net> References: <20170312230026.4632-1-hannes@stressinduktion.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Cc: netdev@vger.kernel.org, bjorn@mork.no, Valdis.Kletnieks@vt.edu, jonas@lippuner.ca, aszlig@redmoonstudios.org To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:35330 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750703AbdCNFBY (ORCPT ); Tue, 14 Mar 2017 01:01:24 -0400 In-Reply-To: <20170312230026.4632-1-hannes@stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Hannes Frederic Sowa Date: Mon, 13 Mar 2017 00:00:26 +0100 > aszlig observed failing ssh tunnels (-w) during initialization since > commit cc9da6cc4f56e0 ("ipv6: addrconf: use stable address generator for > ARPHRD_NONE"). We already had reports that the mentioned commit breaks > Juniper VPN connections. I can't clearly say that the Juniper VPN client > has the same problem, but it is worth a try to hint to this patch. > > Because of the early generation of link local addresses, the kernel now > can start asking for routers on the local subnet much earlier than usual. > Those router solicitation packets arrive inside the ssh channels and > should be transmitted to the tun fd before the configuration scripts > might have upped the interface and made it ready for transmission. > > ssh polls on the interface and receives back a POLL_OUT. It tries to send > the earily router solicitation packet to the tun interface. Unfortunately > it hasn't been up'ed yet by config scripts, thus failing with -EIO. ssh > doesn't retry again and considers the tun interface broken forever. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=121131 > Fixes: cc9da6cc4f56 ("ipv6: addrconf: use stable address generator for ARPHRD_NONE") > Cc: Bjørn Mork > Reported-by: Valdis Kletnieks > Cc: Valdis Kletnieks > Reported-by: Jonas Lippuner > Cc: Jonas Lippuner > Reported-by: aszlig > Cc: aszlig > Signed-off-by: Hannes Frederic Sowa Applied and queued up for -stable.