From patchwork Fri Jun 25 08:25:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jianguo Wu X-Patchwork-Id: 12344055 Received: from m12-18.163.com (m12-18.163.com [220.181.12.18]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4A5A76D0E for ; Fri, 25 Jun 2021 08:26:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=Y31JeG225RRU3Aij+u BaoAsYPyKDDpV1cBtspR68BwE=; b=bw1lWZs3kIbFCvZw0UgfQ/XQCnpm8Pw1Ta wt6mGj9bkSeQbDuMO7pDXBB1BF/UztInIImWX46JWxoFeNd8DKI9LYMcZfF7FpHw qtTxuPEodme36QtEonaz9Qm4Ez2gQ8S5vHPVXIoe9ClPfxQK4F5WugONL3QCAW06 Vxb84wBQc= Received: from localhost.localdomain (unknown [36.111.140.26]) by smtp14 (Coremail) with SMTP id EsCowAAnK+MXk9VgPJySrQ--.35196S6; Fri, 25 Jun 2021 16:26:05 +0800 (CST) From: wujianguo106@163.com To: mptcp@lists.linux.dev Cc: pabeni@redhat.com, mathew.j.martineau@linux.intel.com Subject: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset Date: Fri, 25 Jun 2021 16:25:58 +0800 Message-Id: <1624609559-6786-5-git-send-email-wujianguo106@163.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1624609559-6786-1-git-send-email-wujianguo106@163.com> References: <1624609559-6786-1-git-send-email-wujianguo106@163.com> X-CM-TRANSID: EsCowAAnK+MXk9VgPJySrQ--.35196S6 X-Coremail-Antispam: 1Uf129KBjvJXoW3Ar45CFyrXFW8Ar4UtF48tFb_yoW7tF45pF 1DGw13Jr4kXFWfWr4xAFWkZr1S9w4FkFZ8G3yUKw45Arn8Gw4IkFy5t3Wakr43GFWj9asx JrZ2qFy5uF17AFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jh5rxUUUUU= X-Originating-IP: [36.111.140.26] X-CM-SenderInfo: 5zxmxt5qjx0iiqw6il2tof0z/1tbiNx28kFWBk7oOkwAAsm Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: From: Jianguo Wu If check_fully_established() causes a subflow reset, it should not continue to process the packet in tcp_data_queue(). Add a return value to mptcp_incoming_options(), and return 0 if a subflow has been reset, else return 1. Then drop the packet in tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options() return 0. Fixes: d582484726c4 ("mptcp: fix fallback for MP_JOIN subflows") Signed-off-by: Jianguo Wu --- include/net/mptcp.h | 5 +++-- net/ipv4/tcp_input.c | 19 +++++++++++++++---- net/mptcp/options.c | 22 ++++++++++++++-------- 3 files changed, 32 insertions(+), 14 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index cb580b0..cbd511c 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -105,7 +105,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, unsigned int *size, unsigned int remaining, struct mptcp_out_options *opts); -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, struct mptcp_out_options *opts); @@ -227,9 +227,10 @@ static inline bool mptcp_established_options(struct sock *sk, return false; } -static inline void mptcp_incoming_options(struct sock *sk, +static inline int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) { + return 1; } static inline void mptcp_skb_ext_move(struct sk_buff *to, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7d5e59f..4bacd7d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4247,6 +4247,9 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb) { trace_tcp_receive_reset(sk); + /* mptcp can't tell us to ignore reset pkts, + * so just ignore the return value of mptcp_incoming_options(). + */ if (sk_is_mptcp(sk)) mptcp_incoming_options(sk, skb); @@ -4941,8 +4944,13 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) bool fragstolen; int eaten; - if (sk_is_mptcp(sk)) - mptcp_incoming_options(sk, skb); + /* If a subflow has been reset, the packet should not continue + * to be processed, drop the packet. + */ + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) { + __kfree_skb(skb); + return; + } if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { __kfree_skb(skb); @@ -6523,8 +6531,11 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) case TCP_CLOSING: case TCP_LAST_ACK: if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { - if (sk_is_mptcp(sk)) - mptcp_incoming_options(sk, skb); + /* If a subflow has been reset, the packet should not + * continue to be processed, drop the packet. + */ + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) + goto discard; break; } fallthrough; diff --git a/net/mptcp/options.c b/net/mptcp/options.c index b5850af..f4842b5 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -856,7 +856,8 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, struct mptcp_subflow_context *subflow, struct sk_buff *skb, - struct mptcp_options_received *mp_opt) + struct mptcp_options_received *mp_opt, + bool *subflow_is_rst) { /* here we can process OoO, in-window pkts, only in-sequence 4th ack * will make the subflow fully established @@ -938,6 +939,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, return true; reset: + *subflow_is_rst = true; mptcp_subflow_reset(ssk); return false; } @@ -1035,12 +1037,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, return hmac == mp_opt->ahmac; } -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) +/* Return 0 if a subflow has been reset, else return 1 */ +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); struct mptcp_options_received mp_opt; struct mptcp_ext *mpext; + bool subflow_is_rst = false; if (__mptcp_check_fallback(msk)) { /* Keep it simple and unconditionally trigger send data cleanup and @@ -1053,12 +1057,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) __mptcp_check_push(subflow->conn, sk); __mptcp_data_acked(subflow->conn); mptcp_data_unlock(subflow->conn); - return; + return 1; } mptcp_get_options(sk, skb, &mp_opt); - if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) - return; + if (!check_fully_established(msk, sk, subflow, skb, &mp_opt, &subflow_is_rst)) + return subflow_is_rst ? 0 : 1; if (mp_opt.fastclose && msk->local_key == mp_opt.rcvr_key) { @@ -1100,7 +1104,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) } if (!mp_opt.dss) - return; + return 1; /* we can't wait for recvmsg() to update the ack_seq, otherwise * monodirectional flows will stuck @@ -1119,12 +1123,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) schedule_work(&msk->work)) sock_hold(subflow->conn); - return; + return 1; } mpext = skb_ext_add(skb, SKB_EXT_MPTCP); if (!mpext) - return; + return 1; memset(mpext, 0, sizeof(*mpext)); @@ -1153,6 +1157,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (mpext->csum_reqd) mpext->csum = mp_opt.csum; } + + return 1; } static void mptcp_set_rwin(const struct tcp_sock *tp)