From patchwork Sat Jun 26 09:16:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jianguo Wu X-Patchwork-Id: 12346351 X-Patchwork-Delegate: matthieu.baerts@tessares.net Received: from m12-18.163.com (m12-18.163.com [220.181.12.18]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 88F442FB2 for ; Sat, 26 Jun 2021 09:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=cKTxBtsgUU1di8gPok 9Kk4B2N8Z4kUdJZNF3O4xVGeM=; b=UhmNdHNVSFiPsZozQv1GmhRGKtA9PXZ/bH smvT3ruYC2HDw+dsag4LUDMe4A0IO6rU0JCebv4CO7np4SowgpJ4s8d4Vhw6lmLw i5bVCaB+JZyb94Va+2TlNkbC4wKb+GOcFqI4NuYYEFBMnq/0YmL4vdehjlVoCegO 53aras5ws= Received: from localhost.localdomain (unknown [36.111.140.26]) by smtp14 (Coremail) with SMTP id EsCowAD3_dV38NZgettArg--.471S6; Sat, 26 Jun 2021 17:16:44 +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 v8 4/5] mptcp: avoid processing packet if a subflow reset Date: Sat, 26 Jun 2021 17:16:37 +0800 Message-Id: <1624698998-9029-5-git-send-email-wujianguo106@163.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1624698998-9029-1-git-send-email-wujianguo106@163.com> References: <1624698998-9029-1-git-send-email-wujianguo106@163.com> X-CM-TRANSID: EsCowAD3_dV38NZgettArg--.471S6 X-Coremail-Antispam: 1Uf129KBjvJXoW3Ar45CFyrXF43tr47ZFWrKrg_yoW7Xr1kpF 1DGw43Jr4kWFWfXr4xAFW8Zr1F93yFyFZ8G3yDKw45Arn8Jw4I9Fy8t3Wakr43GFWv9a43 JrZ2vFy5uF17AFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07js6pPUUUUU= X-Originating-IP: [36.111.140.26] X-CM-SenderInfo: 5zxmxt5qjx0iiqw6il2tof0z/1tbiJx29kF5u+2-JYwAAsZ 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 false if a subflow has been reset, else return true. Then drop the packet in tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options() return false. 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 | 19 +++++++++++++------ 3 files changed, 31 insertions(+), 12 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index cb580b0..8b5af68 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); +bool 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 bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) { + return true; } 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..4452455 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1035,7 +1035,8 @@ 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 false if a subflow has been reset, else return true */ +bool 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); @@ -1053,12 +1054,16 @@ 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 true; } mptcp_get_options(sk, skb, &mp_opt); + + /* The subflow can be in close state only if check_fully_established() + * just sent a reset. If so, tell the caller to ignore the current packet. + */ if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) - return; + return sk->sk_state != TCP_CLOSE; if (mp_opt.fastclose && msk->local_key == mp_opt.rcvr_key) { @@ -1100,7 +1105,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) } if (!mp_opt.dss) - return; + return true; /* we can't wait for recvmsg() to update the ack_seq, otherwise * monodirectional flows will stuck @@ -1119,12 +1124,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) schedule_work(&msk->work)) sock_hold(subflow->conn); - return; + return true; } mpext = skb_ext_add(skb, SKB_EXT_MPTCP); if (!mpext) - return; + return true; memset(mpext, 0, sizeof(*mpext)); @@ -1153,6 +1158,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (mpext->csum_reqd) mpext->csum = mp_opt.csum; } + + return true; } static void mptcp_set_rwin(const struct tcp_sock *tp)