From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B0F08063B; Mon, 8 Apr 2024 14:06:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712585202; cv=none; b=XofpwQK3V5LHHGhtxPc8xrVQnpJsuxRv4I06+pS+V6f1zXsYsUGPhBaV/R/KjVFSQVPAG9VQMe8gtHUztw/XbL4UEM0w2Qw7fDPqE9BeWNW8wv4z8UZ5qECcLMdnSnCxbs2bg84FKKR6jUFFhdy40JviD9xHgToxxOoPabmN1SY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712585202; c=relaxed/simple; bh=dxDU2PwRAiFE30XYaWdCEnkXbXC29wzdUMzsgNYZY1w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RR/QnuwriV5z3Rdynu/oZN9VvzCIxoZ45uyRllT3K3hn6yDSN1qo8NrMQkR83JrW5VIFrgWWHn6IcNyX1bbLUwEGeqH+Cw79o35lj15yadm0M8AyETwJMBX8rdlUBi1/belt6PB+j1xoLhSrlFSi8l2zsw0x5ZGyo3RTQPXeWXE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cCPB5vPp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cCPB5vPp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F92BC43390; Mon, 8 Apr 2024 14:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712585200; bh=dxDU2PwRAiFE30XYaWdCEnkXbXC29wzdUMzsgNYZY1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cCPB5vPptw+5+TdDpe5Ypq6x/lNRzTBKeSx/9XSpTVBqgrYlqC9A5XAfYZrR+4SWO Uj2tvneLsqZambLfKAIsS/WF4pS5EbsaEUufdzqDMXJRyN20QPuH2WR2kYVSx8Sx5y yBklOvjP4/v60gvtU4KLzciax1LPWM0aYSoyYRNQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Paasch , Davide Caratti , Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 5.15 687/690] mptcp: dont account accept() of non-MPC client as fallback to TCP Date: Mon, 8 Apr 2024 14:59:13 +0200 Message-ID: <20240408125424.621951185@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240408125359.506372836@linuxfoundation.org> References: <20240408125359.506372836@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Davide Caratti commit 7a1b3490f47e88ec4cbde65f1a77a0f4bc972282 upstream. Current MPTCP servers increment MPTcpExtMPCapableFallbackACK when they accept non-MPC connections. As reported by Christoph, this is "surprising" because the counter might become greater than MPTcpExtMPCapableSYNRX. MPTcpExtMPCapableFallbackACK counter's name suggests it should only be incremented when a connection was seen using MPTCP options, then a fallback to TCP has been done. Let's do that by incrementing it when the subflow context of an inbound MPC connection attempt is dropped. Also, update mptcp_connect.sh kselftest, to ensure that the above MIB does not increment in case a pure TCP client connects to a MPTCP server. Fixes: fc518953bc9c ("mptcp: add and use MIB counter infrastructure") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/449 Signed-off-by: Davide Caratti Reviewed-by: Mat Martineau Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://lore.kernel.org/r/20240329-upstream-net-20240329-fallback-mib-v1-1-324a8981da48@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 3 --- net/mptcp/subflow.c | 3 +++ tools/testing/selftests/net/mptcp/mptcp_connect.sh | 7 +++++++ 3 files changed, 10 insertions(+), 3 deletions(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3018,9 +3018,6 @@ static struct sock *mptcp_accept(struct sock_hold(new_mptcp_sock); newsk = new_mptcp_sock; MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK); - } else { - MPTCP_INC_STATS(sock_net(sk), - MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK); } out: --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -725,6 +725,9 @@ create_child: goto dispose_child; } + if (fallback) + SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK); + subflow_drop_ctx(child); goto out; } --- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh @@ -451,6 +451,7 @@ do_transfer() local stat_cookierx_last=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv") local stat_csum_err_s=$(get_mib_counter "${listener_ns}" "MPTcpExtDataCsumErr") local stat_csum_err_c=$(get_mib_counter "${connector_ns}" "MPTcpExtDataCsumErr") + local stat_tcpfb_last_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK") timeout ${timeout_test} \ ip netns exec ${listener_ns} \ @@ -516,6 +517,7 @@ do_transfer() local stat_cookietx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesSent") local stat_cookierx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv") local stat_ooo_now=$(get_mib_counter "${listener_ns}" "TcpExtTCPOFOQueue") + local stat_tcpfb_now_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableFallbackACK") expect_synrx=$((stat_synrx_last_l)) expect_ackrx=$((stat_ackrx_last_l)) @@ -560,6 +562,11 @@ do_transfer() fi fi + if [ ${stat_ooo_now} -eq 0 ] && [ ${stat_tcpfb_last_l} -ne ${stat_tcpfb_now_l} ]; then + printf "[ FAIL ]\nunexpected fallback to TCP" + rets=1 + fi + if [ $retc -eq 0 ] && [ $rets -eq 0 ]; then printf "[ OK ]" fi