From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F108AC433DF for ; Fri, 15 May 2020 19:31:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6AE920728 for ; Fri, 15 May 2020 19:31:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726197AbgEOTbF (ORCPT ); Fri, 15 May 2020 15:31:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726204AbgEOTbF (ORCPT ); Fri, 15 May 2020 15:31:05 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54BE8C05BD0B for ; Fri, 15 May 2020 12:31:05 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 35E1E15305FA3; Fri, 15 May 2020 12:31:03 -0700 (PDT) Date: Fri, 15 May 2020 12:30:59 -0700 (PDT) Message-Id: <20200515.123059.151278519835306555.davem@davemloft.net> To: pabeni@redhat.com Cc: netdev@vger.kernel.org, edumazet@google.com, cpaasch@apple.com, mptcp@lists.01.org, mathew.j.martineau@linux.intel.com Subject: Re: [PATCH net-next v2 0/3] mptcp: fix MP_JOIN failure handling From: David Miller In-Reply-To: References: X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 15 May 2020 12:31:03 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni Date: Fri, 15 May 2020 19:22:14 +0200 > Currently if we hit an MP_JOIN failure on the third ack, the child socket is > closed with reset, but the request socket is not deleted, causing weird > behaviors. > > The main problem is that MPTCP's MP_JOIN code needs to plug it's own > 'valid 3rd ack' checks and the current TCP callbacks do not allow that. > > This series tries to address the above shortcoming introducing a new MPTCP > specific bit in a 'struct tcp_request_sock' hole, and leveraging that to allow > tcp_check_req releasing the request socket when needed. > > The above allows cleaning-up a bit current MPTCP hooking in tcp_check_req(). > > An alternative solution, possibly cleaner but more invasive, would be > changing the 'bool *own_req' syn_recv_sock() argument into 'int *req_status' > and let MPTCP set it to 'REQ_DROP'. > > v1 -> v2: > - be more conservative about drop_req initialization > > RFC -> v1: > - move the drop_req bit inside tcp_request_sock (Eric) Series applied, thanks Paolo.