From 0348c690ed3731298fb73e37941475ed86b47f54 Mon Sep 17 00:00:00 2001
From: Geliang Tang <geliang.tang@suse.com>
Date: Fri, 22 Apr 2022 14:55:37 -0700
Subject: [PATCH] mptcp: add the fallback check
This patch adds the fallback check in subflow_check_data_avail(). Only
do the fallback when the msk hasn't fallen back yet.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/mptcp/subflow.c | 45 ++++++++++++++++++++++++---------------------
1 file changed, 24 insertions(+), 21 deletions(-)
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index f217926f6a9c4..7f26a5b04ad3d 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1203,35 +1203,38 @@ static bool subflow_check_data_avail(struct sock *ssk)
return false;
fallback:
- /* RFC 8684 section 3.7. */
- if (subflow->send_mp_fail) {
- if (mptcp_has_another_subflow(ssk)) {
+ if (!__mptcp_check_fallback(msk)) {
+ /* RFC 8684 section 3.7. */
+ if (subflow->send_mp_fail) {
+ if (mptcp_has_another_subflow(ssk)) {
+ ssk->sk_err = EBADMSG;
+ tcp_set_state(ssk, TCP_CLOSE);
+ subflow->reset_transient = 0;
+ subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
+ tcp_send_active_reset(ssk, GFP_ATOMIC);
+ while ((skb = skb_peek(&ssk->sk_receive_queue)))
+ sk_eat_skb(ssk, skb);
+ }
+ WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
+ return true;
+ }
+
+ if (subflow->mp_join || subflow->fully_established) {
+ /* fatal protocol error, close the socket.
+ * subflow_error_report() will introduce the appropriate barriers
+ */
ssk->sk_err = EBADMSG;
tcp_set_state(ssk, TCP_CLOSE);
subflow->reset_transient = 0;
- subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
+ subflow->reset_reason = MPTCP_RST_EMPTCP;
tcp_send_active_reset(ssk, GFP_ATOMIC);
- while ((skb = skb_peek(&ssk->sk_receive_queue)))
- sk_eat_skb(ssk, skb);
+ WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
+ return false;
}
- WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
- return true;
- }
- if (subflow->mp_join || subflow->fully_established) {
- /* fatal protocol error, close the socket.
- * subflow_error_report() will introduce the appropriate barriers
- */
- ssk->sk_err = EBADMSG;
- tcp_set_state(ssk, TCP_CLOSE);
- subflow->reset_transient = 0;
- subflow->reset_reason = MPTCP_RST_EMPTCP;
- tcp_send_active_reset(ssk, GFP_ATOMIC);
- WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
- return false;
+ __mptcp_do_fallback(msk);
}
- __mptcp_do_fallback(msk);
skb = skb_peek(&ssk->sk_receive_queue);
subflow->map_valid = 1;
subflow->map_seq = READ_ONCE(msk->ack_seq);
--
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