From patchwork Thu Jun 17 23:46:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 12329797 X-Patchwork-Delegate: mat@martineau.name Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (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 70CE671 for ; Thu, 17 Jun 2021 23:46:32 +0000 (UTC) IronPort-SDR: l6xIUTSRdeyfI61JGdiPwC10I1Du5B8D0phA2EO5ALNDdRjJ5ABPCNFqqeZuMo4m9raZV3H3VG N51TFbYMsgpQ== X-IronPort-AV: E=McAfee;i="6200,9189,10018"; a="270316967" X-IronPort-AV: E=Sophos;i="5.83,281,1616482800"; d="scan'208";a="270316967" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jun 2021 16:46:31 -0700 IronPort-SDR: WQx/aqDgtq7bN7uRZvVOsyFN9gGVGme35GdoNLh3hrZ+K2Ihm1qhYj2MnLdED/Pus4kTkZDwPG LUBI3CDtpObw== X-IronPort-AV: E=Sophos;i="5.83,281,1616482800"; d="scan'208";a="452943908" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.212.250.143]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jun 2021 16:46:31 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Geliang Tang , davem@davemloft.net, kuba@kernel.org, matthieu.baerts@tessares.net, mptcp@lists.linux.dev, pabeni@redhat.com, Mat Martineau Subject: [PATCH net-next 08/16] mptcp: receive checksum for MP_CAPABLE with data Date: Thu, 17 Jun 2021 16:46:14 -0700 Message-Id: <20210617234622.472030-9-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210617234622.472030-1-mathew.j.martineau@linux.intel.com> References: <20210617234622.472030-1-mathew.j.martineau@linux.intel.com> X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Geliang Tang This patch added a new member named csum in struct mptcp_options_received. When parsing the MP_CAPABLE with data, if the checksum is enabled, adjust the expected_opsize. If the receiving option length matches the length with the data checksum, get the checksum value and save it in mp_opt->csum. And in mptcp_incoming_options, pass it to mpext->csum. We always parse any csum/nocsum combination and delay the presence check to later code, to allow reset if missing. Additionally, in the TX path, use the newly introduce ext field to avoid MPTCP csum recomputation on TCP retransmission and unneeded csum update on when setting the data fin_flag. Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau --- include/net/mptcp.h | 3 ++- net/mptcp/options.c | 35 ++++++++++++++++++++++++++--------- net/mptcp/protocol.h | 3 +++ 3 files changed, 31 insertions(+), 10 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 33af68eea96f..d61bbbf11979 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -32,7 +32,8 @@ struct mptcp_ext { mpc_map:1, frozen:1, reset_transient:1; - u8 reset_reason:4; + u8 reset_reason:4, + csum_reqd:1; }; #define MPTCP_RM_IDS_MAX 8 diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 2e2551590ecd..8cbc75868969 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -44,7 +44,20 @@ static void mptcp_parse_option(const struct sk_buff *skb, else expected_opsize = TCPOLEN_MPTCP_MPC_SYN; } - if (opsize != expected_opsize) + + /* Cfr RFC 8684 Section 3.3.0: + * If a checksum is present but its use had + * not been negotiated in the MP_CAPABLE handshake, the receiver MUST + * close the subflow with a RST, as it is not behaving as negotiated. + * If a checksum is not present when its use has been negotiated, the + * receiver MUST close the subflow with a RST, as it is considered + * broken + * We parse even option with mismatching csum presence, so that + * later in subflow_data_ready we can trigger the reset. + */ + if (opsize != expected_opsize && + (expected_opsize != TCPOLEN_MPTCP_MPC_ACK_DATA || + opsize != TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM)) break; /* try to be gentle vs future versions on the initial syn */ @@ -66,11 +79,6 @@ static void mptcp_parse_option(const struct sk_buff *skb, * host requires the use of checksums, checksums MUST be used. * In other words, the only way for checksums not to be used * is if both hosts in their SYNs set A=0." - * - * Section 3.3.0: - * "If a checksum is not present when its use has been - * negotiated, the receiver MUST close the subflow with a RST as - * it is considered broken." */ if (flags & MPTCP_CAP_CHECKSUM_REQD) mp_opt->csum_reqd = 1; @@ -84,7 +92,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, mp_opt->rcvr_key = get_unaligned_be64(ptr); ptr += 8; } - if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA) { + if (opsize >= TCPOLEN_MPTCP_MPC_ACK_DATA) { /* Section 3.1.: * "the data parameters in a MP_CAPABLE are semantically * equivalent to those in a DSS option and can be used @@ -96,9 +104,14 @@ static void mptcp_parse_option(const struct sk_buff *skb, mp_opt->data_len = get_unaligned_be16(ptr); ptr += 2; } - pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d", + if (opsize == TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM) { + mp_opt->csum = (__force __sum16)get_unaligned_be16(ptr); + mp_opt->csum_reqd = 1; + ptr += 2; + } + pr_debug("MP_CAPABLE version=%x, flags=%x, optlen=%d sndr=%llu, rcvr=%llu len=%d csum=%u", version, flags, opsize, mp_opt->sndr_key, - mp_opt->rcvr_key, mp_opt->data_len); + mp_opt->rcvr_key, mp_opt->data_len, mp_opt->csum); break; case MPTCPOPT_MP_JOIN: @@ -1118,6 +1131,10 @@ void 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; + + if (mpext->csum_reqd) + mpext->csum = mp_opt.csum; } } diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 66e5063ac6c9..76194babc754 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -68,6 +68,8 @@ #define TCPOLEN_MPTCP_FASTCLOSE 12 #define TCPOLEN_MPTCP_RST 4 +#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM (TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA) + /* MPTCP MP_JOIN flags */ #define MPTCPOPT_BACKUP BIT(0) #define MPTCPOPT_HMAC_LEN 20 @@ -124,6 +126,7 @@ struct mptcp_options_received { u64 data_seq; u32 subflow_seq; u16 data_len; + __sum16 csum; u16 mp_capable : 1, mp_join : 1, fastclose : 1,