From patchwork Fri Apr 23 18:17:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 426655 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=-21.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 F2CBBC433B4 for ; Fri, 23 Apr 2021 18:17:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C19BD613C2 for ; Fri, 23 Apr 2021 18:17:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243573AbhDWSRz (ORCPT ); Fri, 23 Apr 2021 14:17:55 -0400 Received: from mga03.intel.com ([134.134.136.65]:40508 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232244AbhDWSRw (ORCPT ); Fri, 23 Apr 2021 14:17:52 -0400 IronPort-SDR: 1pTr8p+NWXvo2S0NQhahd5iULzHG8jue6R3LIncoMn+PSq9I+omQCGIP+1Z2VtDimXyTw0cVUK 0M/LbmcZiU/Q== X-IronPort-AV: E=McAfee;i="6200,9189,9963"; a="196172521" X-IronPort-AV: E=Sophos;i="5.82,246,1613462400"; d="scan'208";a="196172521" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Apr 2021 11:17:14 -0700 IronPort-SDR: yIadxR139Tm/3VtAXEVjoW3YSJ90Be8vXGB7pEp1JvZqn4i2YR99dJbPWKH02TrrrKhSQ9pb8a wpYBBEogpqdQ== X-IronPort-AV: E=Sophos;i="5.82,246,1613462400"; d="scan'208";a="402264969" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.254.72.13]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Apr 2021 11:17:14 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Paolo Abeni , davem@davemloft.net, kuba@kernel.org, matthieu.baerts@tessares.net, mptcp@lists.linux.dev, Mat Martineau Subject: [PATCH net-next 3/5] mptcp: ignore unsupported msg flags Date: Fri, 23 Apr 2021 11:17:07 -0700 Message-Id: <20210423181709.330233-4-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210423181709.330233-1-mathew.j.martineau@linux.intel.com> References: <20210423181709.330233-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni Currently mptcp_sendmsg() fails with EOPNOTSUPP if the user-space provides some unsupported flag. That is unexpected and may foul existing applications migrated to MPTCP, which expect a different behavior. Change the mentioned function to silently ignore the unsupported flags except MSG_FASTOPEN. This is the only flags currently not supported by MPTCP with user-space visible side-effects. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/162 Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau --- net/mptcp/protocol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index ae08c563c712..a996dd5bb0c2 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1614,9 +1614,13 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) int ret = 0; long timeo; - if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) + /* we don't support FASTOPEN yet */ + if (msg->msg_flags & MSG_FASTOPEN) return -EOPNOTSUPP; + /* silently ignore everything else */ + msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL; + mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, min_t(size_t, 1 << 20, len))); timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); @@ -1951,9 +1955,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (unlikely(flags & MSG_ERRQUEUE)) return inet_recv_error(sk, msg, len, addr_len); - if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) - return -EOPNOTSUPP; - mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk)); if (unlikely(sk->sk_state == TCP_LISTEN)) { copied = -ENOTCONN;