[PATCH net-next v3 2/6] mptcp: keep rcv_mwnd_seq in sync with subflow rcv_wnd

[Simon Baatz via B4 Relay]

From: Simon Baatz <gmbnomis@xxxxxxxxx>

MPTCP shares a receive window across subflows and applies it at the
subflow level by adjusting each subflow's rcv_wnd when needed.  With
the new TCP tracking of the maximum advertised window sequence,
rcv_mwnd_seq must stay consistent with these subflow-level rcv_wnd
adjustments.

Signed-off-by: Simon Baatz <gmbnomis@xxxxxxxxx>
---
 net/mptcp/options.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 43df4293f58bfbd8a8df6bf24b9f15e0f9e238f6..8a1c5698983cff3082d68290626dd8f1e044527f 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1076,6 +1076,7 @@ static void rwin_update(struct mptcp_sock *msk, struct sock *ssk,
 	 * resync.
 	 */
 	tp->rcv_wnd += mptcp_rcv_wnd - subflow->rcv_wnd_sent;
+	tcp_update_max_rcv_wnd_seq(tp);
 	subflow->rcv_wnd_sent = mptcp_rcv_wnd;
 }
 
@@ -1338,8 +1339,9 @@ static void mptcp_set_rwin(struct tcp_sock *tp, struct tcphdr *th)
 		 */
 		rcv_wnd_new = rcv_wnd_old;
 		win = rcv_wnd_old - ack_seq;
-		tp->rcv_wnd = min_t(u64, win, U32_MAX);
-		new_win = tp->rcv_wnd;
+		new_win = min_t(u64, win, U32_MAX);
+		tp->rcv_wnd = new_win;
+		tcp_update_max_rcv_wnd_seq(tp);
 
 		/* Make sure we do not exceed the maximum possible
 		 * scaled window.

-- 
2.53.0