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: #191 Reviewed-by: Mat Martineau <[email protected]> Signed-off-by: Paolo Abeni <[email protected]>
multipath-tcp · Jul 30, 2021 · b5bc446 · b5bc446
1 parent 28445a0
commit b5bc446
Showing 1 changed file with 4 additions and 2 deletions.
diff --git 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);