tipc: fix link priority propagation

Currently link priority changes isn't handled for active links. In
this patch we resolve this by changing our priority if the peer passes
a valid priority in a state message.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -1458,6 +1458,12 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
 			l->tolerance = peers_tol;
 
+		if (peers_prio && in_range(peers_prio, TIPC_MIN_LINK_PRI,
+					   TIPC_MAX_LINK_PRI)) {
+			l->priority = peers_prio;
+			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
+		}
+
 		l->silent_intv_cnt = 0;
 		l->stats.recv_states++;
 		if (msg_probe(hdr))