From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominique Martinet Subject: Re: tcp hang when socket fills up ? Date: Wed, 18 Apr 2018 13:30:58 +0200 Message-ID: <20180418113058.GA9675@nautica> References: <20180416110158.2cwr3pi3anpkzrw3@breakpoint.cc> <20180417035201.GA10611@nautica> <19b55265-c010-3981-d503-ab8a5a89ed5e@gmail.com> <20180417092044.2hxw4chrn2mpgsyh@unicorn.suse.cz> <20180417123437.GA19885@nautica> <20180417132941.cutzhgbrveatrdsp@breakpoint.cc> <20180418083054.GA29358@nautica> <20180418093622.GB7492@nautica> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Florian Westphal , Michal Kubecek , netdev@vger.kernel.org, Marcelo Ricardo Leitner , Eric Dumazet To: Jozsef Kadlecsik Return-path: Received: from nautica.notk.org ([91.121.71.147]:58246 "EHLO nautica.notk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753384AbeDRLbO (ORCPT ); Wed, 18 Apr 2018 07:31:14 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Jozsef Kadlecsik wrote on Wed, Apr 18, 2018: > Thanks for the testing! One more line is required, however: we have to get > the assured bit set for the connection, see the new patch below. I think it actually was better before. If I understand things correctly at this point (when we get in the case TCP_CONNTRACK_SYN_RECV) we will have seen SYN(out) SYN(in) SYNACK(out), but not the final ACK(in) yet. Leaving old state as it was will not set the assured bit, but that will be set on the next packet because old_state == new_state == established at that point and the connection will really be setup then. I don't think anything will blow up if we do either way, but strictly speaking I'm more comfortable with the former. I'll test the new patch regardless, I left work so can't reproduce anymore but will yell tomorrow if it does explode ;) > The tcp_conntracks state table could be fixed with introducing a new > state, but that part is exposed to userspace (ctnetlink) and ugly > compatibility code would be required for backward compatibility. I agree a new state is more work than it is worth, I'm happy to leave it as is. -- Dominique Martinet | Asmadeus