From mboxrd@z Thu Jan 1 00:00:00 1970 From: Toshiaki Makita Subject: Re: [PATCH v2 1/4] tcp: fix too short FIN_WAIT2 time out Date: Thu, 21 Mar 2013 20:45:17 +0900 Message-ID: <1363866317.3029.21.camel@ubuntu-vm-makita> References: <1363610163.7121.2.camel@ubuntu-vm-makita> <1363610344.7121.5.camel@ubuntu-vm-makita> <20130319.093257.1744500513624729643.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org, makita.toshiaki@lab.ntt.co.jp To: David Miller Return-path: Received: from tama50.ecl.ntt.co.jp ([129.60.39.147]:40843 "EHLO tama50.ecl.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756907Ab3CULp2 (ORCPT ); Thu, 21 Mar 2013 07:45:28 -0400 In-Reply-To: <20130319.093257.1744500513624729643.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2013-03-19 at 09:32 -0400, David Miller wrote: > From: Toshiaki Makita > Date: Mon, 18 Mar 2013 21:39:04 +0900 > > > if (tp->linger2 >= 0) { > > - const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN; > > - > > - if (tmo > 0) { > > - tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); > > - goto out; > > - } > > + tcp_time_wait(sk, TCP_FIN_WAIT2, TCP_TIMEWAIT_LEN); > > + goto out; > > } > > Well, now you're completely ignoring the user's linger setting. If you mention TCP_LINGER2, I don't think I'm ignoring it. It is taken into account in tcp_rcv_state_process() or tcp_close(). If I'm misunderstanding, I'd be glad if you could point out it. > > I really can't take these patches seriously, and will not apply them, > sorry. I think, at least, too short timeout is harmful. If tcp_fin_timeout is set to 61, it will expire in 2 seconds, which cause peer to receive unexpected reset by sending fin. Don't you think there is a problem? Toshiaki Makita