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 45E50C7EE23 for ; Wed, 7 Jun 2023 20:33:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233835AbjFGUdd (ORCPT ); Wed, 7 Jun 2023 16:33:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233798AbjFGUd0 (ORCPT ); Wed, 7 Jun 2023 16:33:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E50781FE2 for ; Wed, 7 Jun 2023 13:33:21 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 6433B64524 for ; Wed, 7 Jun 2023 20:33:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A3FDC4339B; Wed, 7 Jun 2023 20:33:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686170000; bh=ucAgBZYIJgs4s7Z+IiSF7TVuC0Bxxl74gAkSMWVdndE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jZwFswGDekFEUvT0GNXCRXGfNK5lgnjP5auFTUFhvrvNzB4OXAR2vnw3Zx2Pbm8jT 3O884/VXzeyTtlGVfOUOj2c4V0Y+wXwp1TQ056G364TAVbG6FuUGZS4ASFHUsi86dX Vuf9nvmDFSmC1W5DeEsD1ULud3ROdbec0xfq1rlw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ondrej Mosnacek , Mat Martineau , Paolo Abeni , Jakub Kicinski Subject: [PATCH 6.3 257/286] mptcp: fix connect timeout handling Date: Wed, 7 Jun 2023 22:15:56 +0200 Message-ID: <20230607200931.710505824@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230607200922.978677727@linuxfoundation.org> References: <20230607200922.978677727@linuxfoundation.org> User-Agent: quilt/0.67 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 786fc12457268cc9b555dde6c22ae7300d4b40e1 upstream. Ondrej reported a functional issue WRT timeout handling on connect with a nice reproducer. The problem is that the current mptcp connect waits for both the MPTCP socket level timeout, and the first subflow socket timeout. The latter is not influenced/touched by the exposed setsockopt(). Overall the above makes the SO_SNDTIMEO a no-op on connect. Since mptcp_connect is invoked via inet_stream_connect and the latter properly handle the MPTCP level timeout, we can address the issue making the nested subflow level connect always unblocking. This also allow simplifying a bit the code, dropping an ugly hack to handle the fastopen and custom proto_ops connect. The issues predates the blamed commit below, but the current resolution requires the infrastructure introduced there. Fixes: 54f1944ed6d2 ("mptcp: factor out mptcp_connect()") Reported-by: Ondrej Mosnacek Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/399 Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 29 +++++++---------------------- net/mptcp/protocol.h | 1 - 2 files changed, 7 insertions(+), 23 deletions(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1671,7 +1671,6 @@ static int mptcp_sendmsg_fastopen(struct lock_sock(ssk); msg->msg_flags |= MSG_DONTWAIT; - msk->connect_flags = O_NONBLOCK; msk->fastopening = 1; ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL); msk->fastopening = 0; @@ -3610,9 +3609,9 @@ static int mptcp_connect(struct sock *sk * acquired the subflow socket lock, too. */ if (msk->fastopening) - err = __inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags, 1); + err = __inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK, 1); else - err = inet_stream_connect(ssock, uaddr, addr_len, msk->connect_flags); + err = inet_stream_connect(ssock, uaddr, addr_len, O_NONBLOCK); inet_sk(sk)->defer_connect = inet_sk(ssock->sk)->defer_connect; /* on successful connect, the msk state will be moved to established by @@ -3625,12 +3624,10 @@ static int mptcp_connect(struct sock *sk mptcp_copy_inaddrs(sk, ssock->sk); - /* unblocking connect, mptcp-level inet_stream_connect will error out - * without changing the socket state, update it here. + /* silence EINPROGRESS and let the caller inet_stream_connect + * handle the connection in progress */ - if (err == -EINPROGRESS) - sk->sk_socket->state = ssock->state; - return err; + return 0; } static struct proto mptcp_prot = { @@ -3689,18 +3686,6 @@ unlock: return err; } -static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, - int addr_len, int flags) -{ - int ret; - - lock_sock(sock->sk); - mptcp_sk(sock->sk)->connect_flags = flags; - ret = __inet_stream_connect(sock, uaddr, addr_len, flags, 0); - release_sock(sock->sk); - return ret; -} - static int mptcp_listen(struct socket *sock, int backlog) { struct mptcp_sock *msk = mptcp_sk(sock->sk); @@ -3857,7 +3842,7 @@ static const struct proto_ops mptcp_stre .owner = THIS_MODULE, .release = inet_release, .bind = mptcp_bind, - .connect = mptcp_stream_connect, + .connect = inet_stream_connect, .socketpair = sock_no_socketpair, .accept = mptcp_stream_accept, .getname = inet_getname, @@ -3952,7 +3937,7 @@ static const struct proto_ops mptcp_v6_s .owner = THIS_MODULE, .release = inet6_release, .bind = mptcp_bind, - .connect = mptcp_stream_connect, + .connect = inet_stream_connect, .socketpair = sock_no_socketpair, .accept = mptcp_stream_accept, .getname = inet6_getname, --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -297,7 +297,6 @@ struct mptcp_sock { nodelay:1, fastopening:1, in_accept_queue:1; - int connect_flags; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue;