3 files changed, 29 insertions, 6 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index d7afffcc87c1..248e3930c0cb 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1010,7 +1010,24 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb)
 	}
 }
 
-void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts)
+static void mptcp_set_rwin(const struct tcp_sock *tp)
+{
+	const struct sock *ssk = (const struct sock *)tp;
+	const struct mptcp_subflow_context *subflow;
+	struct mptcp_sock *msk;
+	u64 ack_seq;
+
+	subflow = mptcp_subflow_ctx(ssk);
+	msk = mptcp_sk(subflow->conn);
+
+	ack_seq = READ_ONCE(msk->ack_seq) + tp->rcv_wnd;
+
+	if (after64(ack_seq, READ_ONCE(msk->rcv_wnd_sent)))
+		WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
+}
+
+void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
+			 struct mptcp_out_options *opts)
 {
 	if ((OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK |
 	     OPTION_MPTCP_MPC_ACK) & opts->suboptions) {
@@ -1167,4 +1184,7 @@ mp_capable_done:
 					   TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
 		}
 	}
+
+	if (tp)
+		mptcp_set_rwin(tp);
 }
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 8f303de7f500..e1606e072218 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -168,19 +168,19 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb)
 	struct rb_node **p, *parent;
 	u64 seq, end_seq, max_seq;
 	struct sk_buff *skb1;
-	int space;
 
 	seq = MPTCP_SKB_CB(skb)->map_seq;
 	end_seq = MPTCP_SKB_CB(skb)->end_seq;
-	space = tcp_space(sk);
-	max_seq = space > 0 ? space + msk->ack_seq : msk->ack_seq;
+	max_seq = READ_ONCE(msk->rcv_wnd_sent);
 
 	pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq,
 		 RB_EMPTY_ROOT(&msk->out_of_order_queue));
-	if (after64(seq, max_seq)) {
+	if (after64(end_seq, max_seq)) {
 		/* out of window */
 		mptcp_drop(sk, skb);
-		pr_debug("oow by %ld", (unsigned long)seq - (unsigned long)max_seq);
+		pr_debug("oow by %lld, rcv_wnd_sent %llu\n",
+			 (unsigned long long)end_seq - (unsigned long)max_seq,
+			 (unsigned long long)msk->rcv_wnd_sent);
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW);
 		return;
 	}
@@ -2295,6 +2295,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk,
 		mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq);
 		ack_seq++;
 		WRITE_ONCE(msk->ack_seq, ack_seq);
+		WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
 	}
 
 	sock_reset_flag(nsk, SOCK_RCU_FREE);
@@ -2587,6 +2588,7 @@ void mptcp_finish_connect(struct sock *ssk)
 	WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
 	WRITE_ONCE(msk->snd_nxt, msk->write_seq);
 	WRITE_ONCE(msk->ack_seq, ack_seq);
+	WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
 	WRITE_ONCE(msk->can_ack, 1);
 	atomic64_set(&msk->snd_una, msk->write_seq);
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 4d6dd4adaaaf..67f86818203f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -216,6 +216,7 @@ struct mptcp_sock {
 	u64		write_seq;
 	u64		snd_nxt;
 	u64		ack_seq;
+	u64		rcv_wnd_sent;
 	u64		rcv_data_fin_seq;
 	struct sock	*last_snd;
 	int		snd_burst;