From patchwork Thu Apr 8 18:49:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1463999 X-Patchwork-Delegate: pabeni@redhat.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.linux.dev (client-ip=2604:1380:1:3600::1; helo=ewr.edge.kernel.org; envelope-from=mptcp+bounces-198-incoming=patchwork.ozlabs.org@lists.linux.dev; receiver=) Received: from ewr.edge.kernel.org (ewr.edge.kernel.org [IPv6:2604:1380:1:3600::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4FGVgd1ZSmz9sSC for ; Fri, 9 Apr 2021 04:50:04 +1000 (AEST) Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ewr.edge.kernel.org (Postfix) with ESMTPS id 725021C0997 for ; Thu, 8 Apr 2021 18:50:02 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EC7066D15; Thu, 8 Apr 2021 18:50:00 +0000 (UTC) X-Original-To: mptcp@lists.linux.dev Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [193.142.43.52]) (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 671BF6D00 for ; Thu, 8 Apr 2021 18:49:59 +0000 (UTC) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1lUZj4-00015n-0I; Thu, 08 Apr 2021 20:49:58 +0200 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH mptcp 02/10] mptcp: tag sequence_seq with socket state Date: Thu, 8 Apr 2021 20:49:28 +0200 Message-Id: <20210408184936.6245-3-fw@strlen.de> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210408184936.6245-1-fw@strlen.de> References: <20210408184936.6245-1-fw@strlen.de> X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Paolo Abeni suggested to avoid re-syncing new subflows because they inherit options from listener. In case options were set on listener but are not set on mptcp-socket there is no need to do any synchronisation for new subflows. This change sets sockopt_seq of new mptcp sockets to the seq of the mptcp listener sock. Subflow sequence is set to the embedded tcp listener sk. Add a comment explaing why sk_state is involved in sockopt_seq generation. Signed-off-by: Florian Westphal --- net/mptcp/protocol.c | 16 ++++++++++----- net/mptcp/protocol.h | 4 ++++ net/mptcp/sockopt.c | 47 ++++++++++++++++++++++++++++++++++++++++++-- net/mptcp/subflow.c | 4 ++++ 4 files changed, 64 insertions(+), 7 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2233baf03c3a..26e3ffe8840e 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -729,11 +729,14 @@ static bool mptcp_do_flush_join_list(struct mptcp_sock *msk) if (likely(list_empty(&msk->join_list))) return false; - ret = true; spin_lock_bh(&msk->join_list_lock); - list_for_each_entry(subflow, &msk->join_list, node) - mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow)); + list_for_each_entry(subflow, &msk->join_list, node) { + u32 sseq = READ_ONCE(subflow->setsockopt_seq); + mptcp_propagate_sndbuf((struct sock *)msk, mptcp_subflow_tcp_sock(subflow)); + if (READ_ONCE(msk->setsockopt_seq) != sseq) + ret = true; + } list_splice_tail_init(&msk->join_list, &msk->conn_list); spin_unlock_bh(&msk->join_list_lock); @@ -745,7 +748,8 @@ void __mptcp_flush_join_list(struct mptcp_sock *msk) if (likely(!mptcp_do_flush_join_list(msk))) return; - if (!test_and_set_bit(MPTCP_WORK_SYNC_SETSOCKOPT, &msk->flags)) + if (msk->setsockopt_seq && + !test_and_set_bit(MPTCP_WORK_SYNC_SETSOCKOPT, &msk->flags)) mptcp_schedule_work((struct sock *)msk); } @@ -758,7 +762,8 @@ static void mptcp_flush_join_list(struct mptcp_sock *msk) if (!mptcp_do_flush_join_list(msk) && !sync_needed) return; - mptcp_sockopt_sync_all(msk); + if (msk->setsockopt_seq) + mptcp_sockopt_sync_all(msk); } static bool mptcp_timer_pending(struct sock *sk) @@ -2712,6 +2717,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk, msk->snd_nxt = msk->write_seq; msk->snd_una = msk->write_seq; msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; + msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; if (mp_opt->mp_capable) { msk->can_ack = true; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 55fe05a40216..edc0128730df 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -256,6 +256,8 @@ struct mptcp_sock { u64 time; /* start time of measurement window */ u64 rtt_us; /* last maximum rtt of subflows */ } rcvq_space; + + u32 setsockopt_seq; }; #define mptcp_lock_sock(___sk, cb) do { \ @@ -414,6 +416,8 @@ struct mptcp_subflow_context { long delegated_status; struct list_head delegated_node; /* link into delegated_action, protected by local BH */ + u32 setsockopt_seq; + struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ const struct inet_connection_sock_af_ops *icsk_af_ops; diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 4fdc0ad6acf7..b1950be15abe 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -24,6 +24,27 @@ static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk) return msk->first; } +static u32 sockopt_seq_reset(const struct sock *sk) +{ + sock_owned_by_me(sk); + + /* Highbits contain state. Allows to distinguish sockopt_seq + * of listener and established: + * s0 = new_listener() + * sockopt(s0) - seq is 1 + * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0) + * sockopt(s0) - seq increments to 2 on s0 + * sockopt(s1) // seq increments to 2 on s1 (different option) + * new ssk completes join, inherits options from s0 // seq 2 + * Needs sync from mptcp join logic, but ssk->seq == msk->seq + * + * Set High order bits to sk_state so ssk->seq == msk->seq test + * will fail. + */ + + return sk->sk_state << 24u; +} + static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { @@ -350,22 +371,44 @@ int mptcp_getsockopt(struct sock *sk, int level, int optname, return -EOPNOTSUPP; } +static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) +{ +} + void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) { + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + msk_owned_by_me(msk); + + if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { + __mptcp_sockopt_sync(msk, ssk); + + subflow->setsockopt_seq = msk->setsockopt_seq; + } } void mptcp_sockopt_sync_all(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + u32 seq; - msk_owned_by_me(msk); + seq = sockopt_seq_reset(sk); mptcp_for_each_subflow(msk, subflow) { struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + u32 sseq = READ_ONCE(subflow->setsockopt_seq); - mptcp_sockopt_sync(msk, ssk); + if (sseq != msk->setsockopt_seq) { + __mptcp_sockopt_sync(msk, ssk); + WRITE_ONCE(subflow->setsockopt_seq, seq); + } else if (sseq != seq) { + WRITE_ONCE(subflow->setsockopt_seq, seq); + } cond_resched(); } + + msk->setsockopt_seq = seq; } diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index fc7107f8d81b..82e91b00ad39 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -681,6 +681,9 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, goto out; } + /* ssk inherits options of listener sk */ + ctx->setsockopt_seq = listener->setsockopt_seq; + if (ctx->mp_capable) { /* this can't race with mptcp_close(), as the msk is * not yet exposted to user-space @@ -696,6 +699,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, * created mptcp socket */ new_msk->sk_destruct = mptcp_sock_destruct; + mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq; mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1); mptcp_token_accept(subflow_req, mptcp_sk(new_msk)); ctx->conn = new_msk;