From patchwork Thu Nov 5 17:01:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1395133 X-Patchwork-Delegate: fw@strlen.de Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.01.org (client-ip=198.145.21.10; helo=ml01.01.org; envelope-from=mptcp-bounces@lists.01.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=strlen.de Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CRqZ039DTz9sRK for ; Fri, 6 Nov 2020 04:02:00 +1100 (AEDT) Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 5B9E216646E33; Thu, 5 Nov 2020 09:01:58 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a0a:51c0:0:12e:520::1; helo=chamillionaire.breakpoint.cc; envelope-from=fw@breakpoint.cc; receiver= Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id DA85B16646E2F for ; Thu, 5 Nov 2020 09:01:55 -0800 (PST) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1kaie2-0007DO-7I; Thu, 05 Nov 2020 18:01:54 +0100 From: Florian Westphal To: Cc: Florian Westphal Date: Thu, 5 Nov 2020 18:01:26 +0100 Message-Id: <20201105170126.5627-6-fw@strlen.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201105170126.5627-1-fw@strlen.de> References: <20201105170126.5627-1-fw@strlen.de> MIME-Version: 1.0 Message-ID-Hash: 37BAXQCW5GYE3GJRC4AVQG666HQGRH4T X-Message-ID-Hash: 37BAXQCW5GYE3GJRC4AVQG666HQGRH4T X-MailFrom: fw@breakpoint.cc X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header X-Mailman-Version: 3.1.1 Precedence: list Subject: [MPTCP] [PATCH MPTCP 5/5] mptcp: send fastclose if userspace closes socket with unread data List-Id: Discussions regarding MPTCP upstreaming Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Add building & sending of FASTCLOSE option. RFC 8684 describes two methods: A): Host sends an ACK containing the MP_FASTCLOSE option on one subflow [..] On all the other subflows, Host A sends a regular TCP RST to close these subflows and tears them down. [..] R): Host A sends a RST containing the MP_FASTCLOSE option on all subflows [..]. Host A can tear down the subflows and the connection immediately. This implements option R) only: All subflows are re-set with FASTCLOSE. Signed-off-by: Florian Westphal --- net/mptcp/options.c | 35 +++++++++++++++++++++++++++++++++++ net/mptcp/protocol.c | 32 +++++++++++++++++++++++++++++++- net/mptcp/protocol.h | 1 + 3 files changed, 67 insertions(+), 1 deletion(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 0a940687f738..08b60d527de0 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -681,6 +681,31 @@ static bool mptcp_established_options_rm_addr(struct sock *sk, return true; } +static bool mptcp_fastclose(const struct mptcp_sock *msk) +{ + return READ_ONCE(msk->snd_fastclose); +} + +static bool mptcp_established_options_fastclose(struct sock *sk, + unsigned int *size, + unsigned int remaining, + struct mptcp_out_options *opts) +{ + const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); + + if (likely(!mptcp_fastclose(mptcp_sk(subflow->conn)))) + return false; + + if (remaining < TCPOLEN_MPTCP_FASTCLOSE) + return false; + + *size = TCPOLEN_MPTCP_FASTCLOSE; + opts->suboptions |= OPTION_MPTCP_FASTCLOSE; + opts->rcvr_key = subflow->remote_key; + + return true; +} + static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb, unsigned int *size, unsigned int remaining, @@ -691,6 +716,9 @@ static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_bu if (remaining < TCPOLEN_MPTCP_RST) return; + if (mptcp_established_options_fastclose(sk, size, remaining, opts)) + return; + *size = TCPOLEN_MPTCP_RST; opts->suboptions |= OPTION_MPTCP_RST; opts->reset_transient = subflow->reset_transient; @@ -1179,6 +1207,13 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, ptr += 5; } + if (OPTION_MPTCP_FASTCLOSE & opts->suboptions) { + *ptr++ = mptcp_option(MPTCPOPT_MP_FASTCLOSE, + TCPOLEN_MPTCP_FASTCLOSE, 0, 0); + put_unaligned_be64(opts->rcvr_key, ptr); + ptr += 2; + } + if (OPTION_MPTCP_RST & opts->suboptions) *ptr++ = mptcp_option(MPTCPOPT_RST, TCPOLEN_MPTCP_RST, diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 7e9705943813..6b6efa00cad5 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2133,6 +2133,29 @@ static void __mptcp_check_send_data_fin(struct sock *sk) } } +static void __mptcp_send_fastclose(struct sock *sk) +{ + struct mptcp_subflow_context *subflow, *tmp; + struct mptcp_sock *msk = mptcp_sk(sk); + + WRITE_ONCE(msk->snd_fastclose, true); + + __mptcp_flush_join_list(msk); + __mptcp_clear_xmit(sk); + + WRITE_ONCE(msk->snd_nxt, msk->write_seq); + + list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { + struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); + + lock_sock(tcp_sk); + subflow->reset_transient = 0; + subflow->reset_reason = MPTCP_RST_EMPTCP; + mptcp_subflow_reset(tcp_sk); + release_sock(tcp_sk); + } +} + static void __mptcp_wr_shutdown(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); @@ -2185,6 +2208,7 @@ static void mptcp_close(struct sock *sk, long timeout) { struct mptcp_subflow_context *subflow; bool do_cancel_work = false; + bool send_fin = false; lock_sock(sk); sk->sk_shutdown = SHUTDOWN_MASK; @@ -2197,7 +2221,13 @@ static void mptcp_close(struct sock *sk, long timeout) goto cleanup; } - if (mptcp_close_state(sk)) + send_fin = mptcp_close_state(sk); + if (!skb_queue_empty(&sk->sk_receive_queue)) { + __mptcp_send_fastclose(sk); + send_fin = false; + } + + if (send_fin) __mptcp_wr_shutdown(sk); sk_stream_wait_close(sk, timeout); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index d4c99e091cb9..93352044bff9 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -243,6 +243,7 @@ struct mptcp_sock { bool fully_established; bool rcv_data_fin; bool snd_data_fin_enable; + bool snd_fastclose; bool rcv_fastclose; bool use_64bit_ack; /* Set when we received a 64-bit DSN */ spinlock_t join_list_lock;