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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 09B9DC10F14 for ; Sun, 6 Oct 2019 17:57:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD7E020673 for ; Sun, 6 Oct 2019 17:57:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570384653; bh=/MaTq+pll+q1PEJdVMBNeWdM6vcaLTRr/4d4y9623qE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=o2zOoAUxr4kKMlfPVlS/cQ73fgor+4zQMMB6jpcrCO7JFZmLGA8D7PkmUx42gqbwy HCBfOxfW8GzPJVQXyVSL58ejckyJteQTZims8sfVTiCgjPjouxXAn/j8SImVCal30H LvngZO4zzDbM2H5tcpBxuOM9wIowlESpPreZBG9c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729761AbfJFRda (ORCPT ); Sun, 6 Oct 2019 13:33:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:60036 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729747AbfJFRd0 (ORCPT ); Sun, 6 Oct 2019 13:33:26 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4DDB92080F; Sun, 6 Oct 2019 17:33:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570383205; bh=/MaTq+pll+q1PEJdVMBNeWdM6vcaLTRr/4d4y9623qE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qKhBr1Rw+iHpXK8/MhN+B2NlDuk+A41+K8FY9rERr/EL6fCc9ktNdsg5i6U8MJAr6 zEHoEbkpaNpsdyOP6CEojrpIfuOtJB7CYkFPI+Rc9SCsJZfbz71Jx49GXfY+LbOWO8 za9eAF7CzOu0jWL8xQIiEZAKfl8N2oqzL+rVrk2E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Yuchung Cheng , Marek Majkowski , "David S. Miller" Subject: [PATCH 5.2 019/137] tcp: adjust rto_base in retransmits_timed_out() Date: Sun, 6 Oct 2019 19:20:03 +0200 Message-Id: <20191006171210.959241083@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171209.403038733@linuxfoundation.org> References: <20191006171209.403038733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit 3256a2d6ab1f71f9a1bd2d7f6f18eb8108c48d17 ] The cited commit exposed an old retransmits_timed_out() bug which assumed it could call tcp_model_timeout() with TCP_RTO_MIN as rto_base for all states. But flows in SYN_SENT or SYN_RECV state uses a different RTO base (1 sec instead of 200 ms, unless BPF choses another value) This caused a reduction of SYN retransmits from 6 to 4 with the default /proc/sys/net/ipv4/tcp_syn_retries value. Fixes: a41e8a88b06e ("tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state") Signed-off-by: Eric Dumazet Cc: Yuchung Cheng Cc: Marek Majkowski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_timer.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -198,8 +198,13 @@ static bool retransmits_timed_out(struct return false; start_ts = tcp_sk(sk)->retrans_stamp; - if (likely(timeout == 0)) - timeout = tcp_model_timeout(sk, boundary, TCP_RTO_MIN); + if (likely(timeout == 0)) { + unsigned int rto_base = TCP_RTO_MIN; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + rto_base = tcp_timeout_init(sk); + timeout = tcp_model_timeout(sk, boundary, rto_base); + } return (s32)(tcp_time_stamp(tcp_sk(sk)) - start_ts - timeout) >= 0; }