From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 13 Aug 2021 22:15:47 +0000 (-0700)
Subject: mptcp: backup flag from incoming MPJ ack option
X-Git-Tag: accepted/tizen/unified/20230118.172025~6527^2~211^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0460ce229f5b19f501124adf1485176fbfc8f1c2;p=platform%2Fkernel%2Flinux-rpi.git

mptcp: backup flag from incoming MPJ ack option

the parsed incoming backup flag is not propagated
to the subflow itself, the client may end-up using it
to send data.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/191
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 966f777..1151926 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -435,10 +435,12 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 			goto do_reset;
 		}
 
+		subflow->backup = mp_opt.backup;
 		subflow->thmac = mp_opt.thmac;
 		subflow->remote_nonce = mp_opt.nonce;
-		pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
-			 subflow->thmac, subflow->remote_nonce);
+		pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u backup=%d",
+			 subflow, subflow->thmac, subflow->remote_nonce,
+			 subflow->backup);
 
 		if (!subflow_thmac_valid(subflow)) {
 			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINACKMAC);