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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 65998C4360C for ; Wed, 2 Oct 2019 23:38:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 426D8222C0 for ; Wed, 2 Oct 2019 23:38:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729395AbfJBXiS (ORCPT ); Wed, 2 Oct 2019 19:38:18 -0400 Received: from mga04.intel.com ([192.55.52.120]:16472 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729181AbfJBXhm (ORCPT ); Wed, 2 Oct 2019 19:37:42 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Oct 2019 16:37:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,250,1566889200"; d="scan'208";a="366862630" Received: from mjmartin-nuc02.mjmartin-nuc02 (HELO mjmartin-nuc02.sea.intel.com) ([10.251.30.230]) by orsmga005.jf.intel.com with ESMTP; 02 Oct 2019 16:37:23 -0700 From: Mat Martineau To: netdev@vger.kernel.org, edumazet@google.com Cc: Paolo Abeni , cpaasch@apple.com, fw@strlen.de, peter.krystad@linux.intel.com, dcaratti@redhat.com, matthieu.baerts@tessares.net Subject: [RFC PATCH v2 35/45] mptcp: update per unacked sequence on pkt reception Date: Wed, 2 Oct 2019 16:36:45 -0700 Message-Id: <20191002233655.24323-36-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191002233655.24323-1-mathew.j.martineau@linux.intel.com> References: <20191002233655.24323-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni So that we keep per unacked sequence number consistent; since we update per msk data, use an atomic64 cmpxcgh() to protect against concurrent updates from multiple subflows. Initialize the snd_una at connect()/accept() time. Signed-off-by: Paolo Abeni --- net/mptcp/options.c | 45 ++++++++++++++++++++++++++++++++++++++------ net/mptcp/protocol.c | 2 ++ net/mptcp/protocol.h | 1 + 3 files changed, 42 insertions(+), 6 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index ce298ecc64f5..2427fff98091 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -540,6 +540,39 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, return false; } +static u64 expand_ack(u64 old_ack, u64 cur_ack, bool use_64bit) +{ + u32 old_ack32, cur_ack32; + + if (use_64bit) + return cur_ack; + + old_ack32 = (u32)old_ack; + cur_ack32 = (u32)cur_ack; + cur_ack = (old_ack & GENMASK_ULL(63, 32)) + cur_ack32; + if (unlikely(before(cur_ack32, old_ack32))) + return cur_ack + (1LL << 32); + return cur_ack; +} + +void update_una(struct mptcp_sock *msk, struct mptcp_options_received *mp_opt) +{ + u64 new_snd_una, snd_una, old_snd_una = atomic64_read(&msk->snd_una); + + /* avoid ack expansion on update conflict, to reduce the risk of + * wrongly expanding to a future ack sequence number, which is way + * more dangerous than missing an ack + */ + new_snd_una = expand_ack(old_snd_una, mp_opt->data_ack, mp_opt->ack64); + while (after64(new_snd_una, old_snd_una)) { + snd_una = old_snd_una; + old_snd_una = atomic64_cmpxchg(&msk->snd_una, snd_una, + new_snd_una); + if (old_snd_una == snd_una) + break; + } +} + void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, struct tcp_options_received *opt_rx) { @@ -563,6 +596,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, if (!mp_opt->dss) return; + /* we can't wait for recvmsg() to update the ack_seq, otherwise + * monodirectional flows will stuck + */ + if (msk && mp_opt->use_ack) + update_una(msk, mp_opt); + mpext = skb_ext_add(skb, SKB_EXT_MPTCP); if (!mpext) return; @@ -579,12 +618,6 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, mpext->use_checksum = mp_opt->use_checksum; } - if (mp_opt->use_ack) { - mpext->data_ack = mp_opt->data_ack; - mpext->use_ack = 1; - mpext->ack64 = mp_opt->ack64; - } - mpext->data_fin = mp_opt->data_fin; if (msk) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index c8ee20963887..2c64435aedd8 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -688,6 +688,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, mptcp_crypto_key_sha1(msk->remote_key, NULL, &ack_seq); msk->write_seq = subflow->idsn + 1; + atomic64_set(&msk->snd_una, msk->write_seq); ack_seq++; msk->ack_seq = ack_seq; subflow->map_seq = ack_seq; @@ -822,6 +823,7 @@ void mptcp_finish_connect(struct sock *sk, int mp_capable) mptcp_crypto_key_sha1(msk->remote_key, NULL, &ack_seq); msk->write_seq = subflow->idsn + 1; + atomic64_set(&msk->snd_una, msk->write_seq); ack_seq++; msk->ack_seq = ack_seq; subflow->map_seq = ack_seq; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 56df4f46f313..45646e38aa4c 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -119,6 +119,7 @@ struct mptcp_sock { u64 remote_key; u64 write_seq; u64 ack_seq; + atomic64_t snd_una; u32 token; unsigned long flags; u16 dport; -- 2.23.0