From patchwork Fri Aug 27 00:44:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 503698 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 85C55C4320E for ; Fri, 27 Aug 2021 00:45:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 601C460FC0 for ; Fri, 27 Aug 2021 00:45:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243884AbhH0Apw (ORCPT ); Thu, 26 Aug 2021 20:45:52 -0400 Received: from mga01.intel.com ([192.55.52.88]:46997 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243862AbhH0Apu (ORCPT ); Thu, 26 Aug 2021 20:45:50 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10088"; a="240080599" X-IronPort-AV: E=Sophos;i="5.84,354,1620716400"; d="scan'208";a="240080599" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2021 17:45:02 -0700 X-IronPort-AV: E=Sophos;i="5.84,354,1620716400"; d="scan'208";a="599007129" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.209.68.199]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2021 17:45:01 -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: consolidate in_opt sub-options fields in a bitmask Date: Thu, 26 Aug 2021 17:44:52 -0700 Message-Id: <20210827004455.286754-4-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210827004455.286754-1-mathew.j.martineau@linux.intel.com> References: <20210827004455.286754-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni This makes input options processing more consistent with output ones and will simplify the next patch. Also avoid clearing the suboption field after processing it, since it's not needed. Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau --- net/mptcp/options.c | 74 ++++++++++++++++++-------------------------- net/mptcp/protocol.c | 4 +-- net/mptcp/protocol.h | 18 +++++------ net/mptcp/subflow.c | 40 ++++++++++++++---------- 4 files changed, 63 insertions(+), 73 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 79b68ae9ef4d..0d33c020062f 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -81,11 +81,11 @@ static void mptcp_parse_option(const struct sk_buff *skb, * is if both hosts in their SYNs set A=0." */ if (flags & MPTCP_CAP_CHECKSUM_REQD) - mp_opt->csum_reqd = 1; + mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD; mp_opt->deny_join_id0 = !!(flags & MPTCP_CAP_DENY_JOIN_ID0); - mp_opt->mp_capable = 1; + mp_opt->suboptions |= OPTIONS_MPTCP_MPC; if (opsize >= TCPOLEN_MPTCP_MPC_SYNACK) { mp_opt->sndr_key = get_unaligned_be64(ptr); ptr += 8; @@ -100,7 +100,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, * equivalent to those in a DSS option and can be used * interchangeably." */ - mp_opt->dss = 1; + mp_opt->suboptions |= OPTION_MPTCP_DSS; mp_opt->use_map = 1; mp_opt->mpc_map = 1; mp_opt->data_len = get_unaligned_be16(ptr); @@ -108,7 +108,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, } if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM) { mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr); - mp_opt->csum_reqd = 1; + mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD; ptr += 2; } pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d csum=%u", @@ -117,7 +117,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, break; case MPTCPOPT_MP_JOIN: - mp_opt->mp_join = 1; + mp_opt->suboptions |= OPTIONS_MPTCP_MPJ; if (opsize == TCPOLEN_MPTCP_MPJ_SYN) { mp_opt->backup = *ptr++ & MPTCPOPT_BACKUP; mp_opt->join_id = *ptr++; @@ -143,7 +143,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, memcpy(mp_opt->hmac, ptr, MPTCPOPT_HMAC_LEN); pr_debug("MP_JOIN hmac"); } else { - mp_opt->mp_join = 0; + mp_opt->suboptions &= ~OPTIONS_MPTCP_MPJ; } break; @@ -191,8 +191,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) break; - mp_opt->dss = 1; - + mp_opt->suboptions |= OPTION_MPTCP_DSS; if (mp_opt->use_ack) { if (mp_opt->ack64) { mp_opt->data_ack = get_unaligned_be64(ptr); @@ -221,14 +220,15 @@ static void mptcp_parse_option(const struct sk_buff *skb, ptr += 2; if (opsize == expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) { - mp_opt->csum_reqd = 1; + mp_opt->suboptions |= OPTION_MPTCP_CSUMREQD; mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr); ptr += 2; } pr_debug("data_seq=%llu subflow_seq=%u data_len=%u csum=%d:%u", mp_opt->data_seq, mp_opt->subflow_seq, - mp_opt->data_len, mp_opt->csum_reqd, mp_opt->csum); + mp_opt->data_len, !!(mp_opt->suboptions & OPTION_MPTCP_CSUMREQD), + mp_opt->csum); } break; @@ -259,7 +259,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, break; } - mp_opt->add_addr = 1; + mp_opt->suboptions |= OPTION_MPTCP_ADD_ADDR; mp_opt->addr.id = *ptr++; mp_opt->addr.port = 0; mp_opt->ahmac = 0; @@ -299,7 +299,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, ptr++; - mp_opt->rm_addr = 1; + mp_opt->suboptions |= OPTION_MPTCP_RM_ADDR; mp_opt->rm_list.nr = opsize - TCPOLEN_MPTCP_RM_ADDR_BASE; for (i = 0; i < mp_opt->rm_list.nr; i++) mp_opt->rm_list.ids[i] = *ptr++; @@ -310,7 +310,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, if (opsize != TCPOLEN_MPTCP_PRIO) break; - mp_opt->mp_prio = 1; + mp_opt->suboptions |= OPTION_MPTCP_PRIO; mp_opt->backup = *ptr++ & MPTCP_PRIO_BKUP; pr_debug("MP_PRIO: prio=%d", mp_opt->backup); break; @@ -322,7 +322,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, ptr += 2; mp_opt->rcvr_key = get_unaligned_be64(ptr); ptr += 8; - mp_opt->fastclose = 1; + mp_opt->suboptions |= OPTION_MPTCP_FASTCLOSE; break; case MPTCPOPT_RST: @@ -331,7 +331,8 @@ static void mptcp_parse_option(const struct sk_buff *skb, if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) break; - mp_opt->reset = 1; + + mp_opt->suboptions |= OPTION_MPTCP_RST; flags = *ptr++; mp_opt->reset_transient = flags & MPTCP_RST_TRANSIENT; mp_opt->reset_reason = *ptr; @@ -342,7 +343,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, break; ptr += 2; - mp_opt->mp_fail = 1; + mp_opt->suboptions |= OPTION_MPTCP_FAIL; mp_opt->fail_seq = get_unaligned_be64(ptr); pr_debug("MP_FAIL: data_seq=%llu", mp_opt->fail_seq); break; @@ -361,16 +362,7 @@ void mptcp_get_options(const struct sock *sk, int length; /* initialize option status */ - mp_opt->mp_capable = 0; - mp_opt->mp_join = 0; - mp_opt->add_addr = 0; - mp_opt->fastclose = 0; - mp_opt->rm_addr = 0; - mp_opt->dss = 0; - mp_opt->mp_prio = 0; - mp_opt->reset = 0; - mp_opt->csum_reqd = 0; - mp_opt->mp_fail = 0; + mp_opt->suboptions = 0; length = (th->doff * 4) - sizeof(struct tcphdr); ptr = (const unsigned char *)(th + 1); @@ -924,7 +916,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, */ if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 && TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq && - subflow->mp_join && mp_opt->mp_join && + subflow->mp_join && (mp_opt->suboptions & OPTIONS_MPTCP_MPJ) && READ_ONCE(msk->pm.server_side)) tcp_send_ack(ssk); goto fully_established; @@ -941,8 +933,8 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, return subflow->mp_capable; } - if ((mp_opt->dss && mp_opt->use_ack) || - (mp_opt->add_addr && !mp_opt->echo)) { + if (((mp_opt->suboptions & OPTION_MPTCP_DSS) && mp_opt->use_ack) || + ((mp_opt->suboptions & OPTION_MPTCP_ADD_ADDR) && !mp_opt->echo)) { /* subflows are fully established as soon as we get any * additional ack, including ADD_ADDR. */ @@ -955,7 +947,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, * then fallback to TCP. Fallback scenarios requires a reset for * MP_JOIN subflows. */ - if (!mp_opt->mp_capable) { + if (!(mp_opt->suboptions & OPTIONS_MPTCP_MPC)) { if (subflow->mp_join) goto reset; subflow->mp_capable = 0; @@ -1119,13 +1111,13 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) return sk->sk_state != TCP_CLOSE; - if (mp_opt.fastclose && + if ((mp_opt.suboptions & OPTION_MPTCP_FASTCLOSE) && msk->local_key == mp_opt.rcvr_key) { WRITE_ONCE(msk->rcv_fastclose, true); mptcp_schedule_work((struct sock *)msk); } - if (mp_opt.add_addr && add_addr_hmac_valid(msk, &mp_opt)) { + if ((mp_opt.suboptions & OPTION_MPTCP_ADD_ADDR) && add_addr_hmac_valid(msk, &mp_opt)) { if (!mp_opt.echo) { mptcp_pm_add_addr_received(msk, &mp_opt.addr); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR); @@ -1137,34 +1129,28 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (mp_opt.addr.port) MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_PORTADD); - - mp_opt.add_addr = 0; } - if (mp_opt.rm_addr) { + if (mp_opt.suboptions & OPTION_MPTCP_RM_ADDR) mptcp_pm_rm_addr_received(msk, &mp_opt.rm_list); - mp_opt.rm_addr = 0; - } - if (mp_opt.mp_prio) { + if (mp_opt.suboptions & OPTION_MPTCP_PRIO) { mptcp_pm_mp_prio_received(sk, mp_opt.backup); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIORX); - mp_opt.mp_prio = 0; } - if (mp_opt.mp_fail) { + if (mp_opt.suboptions & OPTION_MPTCP_FAIL) { mptcp_pm_mp_fail_received(sk, mp_opt.fail_seq); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILRX); - mp_opt.mp_fail = 0; } - if (mp_opt.reset) { + if (mp_opt.suboptions & OPTION_MPTCP_RST) { subflow->reset_seen = 1; subflow->reset_reason = mp_opt.reset_reason; subflow->reset_transient = mp_opt.reset_transient; } - if (!mp_opt.dss) + if (!(mp_opt.suboptions & OPTION_MPTCP_DSS)) return true; /* we can't wait for recvmsg() to update the ack_seq, otherwise @@ -1213,7 +1199,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) } mpext->data_len = mp_opt.data_len; mpext->use_map = 1; - mpext->csum_reqd = mp_opt.csum_reqd; + mpext->csum_reqd = !!(mp_opt.suboptions & OPTION_MPTCP_CSUMREQD); if (mpext->csum_reqd) mpext->csum = mp_opt.csum; diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 22214a58d892..1a408395e78f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2832,7 +2832,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk, msk->token = subflow_req->token; msk->subflow = NULL; WRITE_ONCE(msk->fully_established, false); - if (mp_opt->csum_reqd) + if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD) WRITE_ONCE(msk->csum_enabled, true); msk->write_seq = subflow_req->idsn + 1; @@ -2841,7 +2841,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk, msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; - if (mp_opt->mp_capable) { + if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) { msk->can_ack = true; msk->remote_key = mp_opt->sndr_key; mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 9a0d91f92bbc..d7aba1c4dc48 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -29,6 +29,13 @@ #define OPTION_MPTCP_DSS BIT(11) #define OPTION_MPTCP_FAIL BIT(12) +#define OPTION_MPTCP_CSUMREQD BIT(13) + +#define OPTIONS_MPTCP_MPC (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \ + OPTION_MPTCP_MPC_ACK) +#define OPTIONS_MPTCP_MPJ (OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \ + OPTION_MPTCP_MPJ_SYNACK) + /* MPTCP option subtypes */ #define MPTCPOPT_MP_CAPABLE 0 #define MPTCPOPT_MP_JOIN 1 @@ -132,16 +139,7 @@ struct mptcp_options_received { u32 subflow_seq; u16 data_len; __sum16 csum; - u16 mp_capable : 1, - mp_join : 1, - fastclose : 1, - reset : 1, - dss : 1, - add_addr : 1, - rm_addr : 1, - mp_prio : 1, - csum_reqd : 1, - mp_fail : 1; + u16 suboptions; u32 token; u32 nonce; u16 use_map:1, diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 54b7ffc21861..1de7ce883c37 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -141,6 +141,7 @@ static int subflow_check_req(struct request_sock *req, struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct mptcp_options_received mp_opt; + bool opt_mp_capable, opt_mp_join; pr_debug("subflow_req=%p, listener=%p", subflow_req, listener); @@ -154,16 +155,18 @@ static int subflow_check_req(struct request_sock *req, mptcp_get_options(sk_listener, skb, &mp_opt); - if (mp_opt.mp_capable) { + opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC); + opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ); + if (opt_mp_capable) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE); - if (mp_opt.mp_join) + if (opt_mp_join) return 0; - } else if (mp_opt.mp_join) { + } else if (opt_mp_join) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINSYNRX); } - if (mp_opt.mp_capable && listener->request_mptcp) { + if (opt_mp_capable && listener->request_mptcp) { int err, retries = MPTCP_TOKEN_MAX_RETRIES; subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; @@ -194,7 +197,7 @@ static int subflow_check_req(struct request_sock *req, else SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT); - } else if (mp_opt.mp_join && listener->request_mptcp) { + } else if (opt_mp_join && listener->request_mptcp) { subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq; subflow_req->mp_join = 1; subflow_req->backup = mp_opt.backup; @@ -243,15 +246,18 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener); struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct mptcp_options_received mp_opt; + bool opt_mp_capable, opt_mp_join; int err; subflow_init_req(req, sk_listener); mptcp_get_options(sk_listener, skb, &mp_opt); - if (mp_opt.mp_capable && mp_opt.mp_join) + opt_mp_capable = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPC); + opt_mp_join = !!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ); + if (opt_mp_capable && opt_mp_join) return -EINVAL; - if (mp_opt.mp_capable && listener->request_mptcp) { + if (opt_mp_capable && listener->request_mptcp) { if (mp_opt.sndr_key == 0) return -EINVAL; @@ -262,7 +268,7 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, subflow_req->mp_capable = 1; subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; - } else if (mp_opt.mp_join && listener->request_mptcp) { + } else if (opt_mp_join && listener->request_mptcp) { if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) return -EINVAL; @@ -394,7 +400,6 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) subflow->icsk_af_ops->sk_rx_dst_set(sk, skb); - /* be sure no special action on any packet other than syn-ack */ if (subflow->conn_finished) return; @@ -407,7 +412,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) mptcp_get_options(sk, skb, &mp_opt); if (subflow->request_mptcp) { - if (!mp_opt.mp_capable) { + if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) { MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); mptcp_do_fallback(sk); @@ -415,7 +420,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) goto fallback; } - if (mp_opt.csum_reqd) + if (mp_opt.suboptions & OPTION_MPTCP_CSUMREQD) WRITE_ONCE(mptcp_sk(parent)->csum_enabled, true); if (mp_opt.deny_join_id0) WRITE_ONCE(mptcp_sk(parent)->pm.remote_deny_join_id0, true); @@ -430,7 +435,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) } else if (subflow->request_join) { u8 hmac[SHA256_DIGEST_SIZE]; - if (!mp_opt.mp_join) { + if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ)) { subflow->reset_reason = MPTCP_RST_EMPTCP; goto do_reset; } @@ -636,10 +641,10 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); - /* After child creation we must look for 'mp_capable' even when options + /* After child creation we must look for MPC even when options * are not parsed */ - mp_opt.mp_capable = 0; + mp_opt.suboptions = 0; /* hopefully temporary handling for MP_JOIN+syncookie */ subflow_req = mptcp_subflow_rsk(req); @@ -659,7 +664,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, * options. */ mptcp_get_options(sk, skb, &mp_opt); - if (!mp_opt.mp_capable) { + if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) { fallback = true; goto create_child; } @@ -669,7 +674,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, fallback = true; } else if (subflow_req->mp_join) { mptcp_get_options(sk, skb, &mp_opt); - if (!mp_opt.mp_join || !subflow_hmac_valid(req, &mp_opt) || + if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) || + !subflow_hmac_valid(req, &mp_opt) || !mptcp_can_accept_new_subflow(subflow_req->msk)) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); fallback = true; @@ -726,7 +732,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, /* with OoO packets we can reach here without ingress * mpc option */ - if (mp_opt.mp_capable) + if (mp_opt.suboptions & OPTIONS_MPTCP_MPC) mptcp_subflow_fully_established(ctx, &mp_opt); } else if (ctx->mp_join) { struct mptcp_sock *owner;