From patchwork Wed May 31 19:37:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 13262570 X-Patchwork-Delegate: kuba@kernel.org 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 40509200BC; Wed, 31 May 2023 19:37:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADBF2C4339E; Wed, 31 May 2023 19:37:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685561837; bh=4WKY0Pr/dAihpTUtgtlYI/RMZE9/4UvbyGFh0IkjtPw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ixEsKQZ8xkeS2MoXm5lndgA1dyFJOfDAEHlcCUS6BvFwpWmZfSBdbRgoJzBx//mdA xTWrNm9OtTnTqjcsm3sMiNtHm7LmR3uwMYjCGDy5uzNTtujRPx6caUFcSMpKeSqMKT qEjpS2Fz4fm3oPaF80H0wkjqLbmWncdr1JuGz6yDTxPRSRWHJ5W4DA9bkJDW+ZdhS1 RPKBbROm7WZW0CQIIiXrNveniReHgCJtw8/14Tde9ZPx1yd9BUh/anv6kDJ2mi4+/L r2TvjflAX84ERlDxdJ6mqNJKZhhoNar3axlhOSRKLIULLDxut2kmWmsjAvLV5FtRes mpQG1Ev4C7ywQ== From: Mat Martineau Date: Wed, 31 May 2023 12:37:03 -0700 Subject: [PATCH net 1/6] mptcp: fix connect timeout handling Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20230531-send-net-20230531-v1-1-47750c420571@kernel.org> References: <20230531-send-net-20230531-v1-0-47750c420571@kernel.org> In-Reply-To: <20230531-send-net-20230531-v1-0-47750c420571@kernel.org> To: Matthieu Baerts , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Geliang Tang Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, Mat Martineau , Ondrej Mosnacek , stable@vger.kernel.org X-Mailer: b4 0.12.2 X-Patchwork-Delegate: kuba@kernel.org From: Paolo Abeni 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 --- net/mptcp/protocol.c | 29 +++++++---------------------- net/mptcp/protocol.h | 1 - 2 files changed, 7 insertions(+), 23 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 08dc53f56bc2..9cafd3b89908 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1702,7 +1702,6 @@ static int mptcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, 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; @@ -3617,9 +3616,9 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) * 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 @@ -3632,12 +3631,10 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 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 = { @@ -3696,18 +3693,6 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 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); @@ -3859,7 +3844,7 @@ static const struct proto_ops mptcp_stream_ops = { .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, @@ -3954,7 +3939,7 @@ static const struct proto_ops mptcp_v6_stream_ops = { .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, diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 2d7b2c80a164..de4667dafe59 100644 --- 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;