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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78A51C433EF for ; Mon, 28 Feb 2022 17:55:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239476AbiB1R4b (ORCPT ); Mon, 28 Feb 2022 12:56:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238846AbiB1Ryq (ORCPT ); Mon, 28 Feb 2022 12:54:46 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4F762BE3; Mon, 28 Feb 2022 09:44:16 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 587B9B815AB; Mon, 28 Feb 2022 17:44:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1954C340E7; Mon, 28 Feb 2022 17:44:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646070254; bh=re8j0cwAUKK6PJWb56yhqhBnF9YWtkD/UuOaJsCwDGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=slrqwLYUAMWcNjj05Fp0y5XJ56R9ckXJpNQ/L1xhsyo+T5QqZ6KZ21SPWkDGyXoBR ZUGxxzTYumBf7YfqDCqBHPQxVqfqz620UMzxBK3uFemwTUJVP0YPGX4Rj2v0Jbkb1v qgd8fRp7tV9af4hbBY2eEVqFAXLfExb9bq4A92IQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Abeni , Mat Martineau , "David S. Miller" Subject: [PATCH 5.16 041/164] selftests: mptcp: be more conservative with cookie MPJ limits Date: Mon, 28 Feb 2022 18:23:23 +0100 Message-Id: <20220228172404.008132583@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220228172359.567256961@linuxfoundation.org> References: <20220228172359.567256961@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Abeni commit e35f885b357d47e04380a2056d1b2cc3e6f4f24b upstream. Since commit 2843ff6f36db ("mptcp: remote addresses fullmesh"), an MPTCP client can attempt creating multiple MPJ subflow simultaneusly. In such scenario the server, when syncookies are enabled, could end-up accepting incoming MPJ syn even above the configured subflow limit, as the such limit can be enforced in a reliable way only after the subflow creation. In case of syncookie, only after the 3rd ack reception. As a consequence the related self-tests case sporadically fails, as it verify that the server always accept the expected number of MPJ syn. Address the issues relaxing the MPJ syn number constrain. Note that the check on the accepted number of MPJ 3rd ack still remains intact. Fixes: 2843ff6f36db ("mptcp: remote addresses fullmesh") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -624,6 +624,7 @@ chk_join_nr() local ack_nr=$4 local count local dump_stats + local with_cookie printf "%02u %-36s %s" "$TEST_COUNT" "$msg" "syn" count=`ip netns exec $ns1 nstat -as | grep MPTcpExtMPJoinSynRx | awk '{print $2}'` @@ -637,12 +638,20 @@ chk_join_nr() fi echo -n " - synack" + with_cookie=`ip netns exec $ns2 sysctl -n net.ipv4.tcp_syncookies` count=`ip netns exec $ns2 nstat -as | grep MPTcpExtMPJoinSynAckRx | awk '{print $2}'` [ -z "$count" ] && count=0 if [ "$count" != "$syn_ack_nr" ]; then - echo "[fail] got $count JOIN[s] synack expected $syn_ack_nr" - ret=1 - dump_stats=1 + # simult connections exceeding the limit with cookie enabled could go up to + # synack validation as the conn limit can be enforced reliably only after + # the subflow creation + if [ "$with_cookie" = 2 ] && [ "$count" -gt "$syn_ack_nr" ] && [ "$count" -le "$syn_nr" ]; then + echo -n "[ ok ]" + else + echo "[fail] got $count JOIN[s] synack expected $syn_ack_nr" + ret=1 + dump_stats=1 + fi else echo -n "[ ok ]" fi