+
+#[test]
+fn accept_busted_but_better_fee() {
+ // If a peer sends us a fee update that is too low, but higher than our previous channel
+ // feerate, we should accept it. In the future we may want to consider closing the channel
+ // later, but for now we only accept the update.
+ let mut chanmon_cfgs = create_chanmon_cfgs(2);
+ let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+ let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+ let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+ create_chan_between_nodes(&nodes[0], &nodes[1], channelmanager::provided_init_features(), channelmanager::provided_init_features());
+
+ // Set nodes[1] to expect 5,000 sat/kW.
+ {
+ let mut feerate_lock = chanmon_cfgs[1].fee_estimator.sat_per_kw.lock().unwrap();
+ *feerate_lock = 5000;
+ }
+
+ // If nodes[0] increases their feerate, even if its not enough, nodes[1] should accept it.
+ {
+ let mut feerate_lock = chanmon_cfgs[0].fee_estimator.sat_per_kw.lock().unwrap();
+ *feerate_lock = 1000;
+ }
+ nodes[0].node.timer_tick_occurred();
+ check_added_monitors!(nodes[0], 1);
+
+ let events = nodes[0].node.get_and_clear_pending_msg_events();
+ assert_eq!(events.len(), 1);
+ match events[0] {
+ MessageSendEvent::UpdateHTLCs { updates: msgs::CommitmentUpdate { ref update_fee, ref commitment_signed, .. }, .. } => {
+ nodes[1].node.handle_update_fee(&nodes[0].node.get_our_node_id(), update_fee.as_ref().unwrap());
+ commitment_signed_dance!(nodes[1], nodes[0], commitment_signed, false);
+ },
+ _ => panic!("Unexpected event"),
+ };
+
+ // If nodes[0] increases their feerate further, even if its not enough, nodes[1] should accept
+ // it.
+ {
+ let mut feerate_lock = chanmon_cfgs[0].fee_estimator.sat_per_kw.lock().unwrap();
+ *feerate_lock = 2000;
+ }
+ nodes[0].node.timer_tick_occurred();
+ check_added_monitors!(nodes[0], 1);
+
+ let events = nodes[0].node.get_and_clear_pending_msg_events();
+ assert_eq!(events.len(), 1);
+ match events[0] {
+ MessageSendEvent::UpdateHTLCs { updates: msgs::CommitmentUpdate { ref update_fee, ref commitment_signed, .. }, .. } => {
+ nodes[1].node.handle_update_fee(&nodes[0].node.get_our_node_id(), update_fee.as_ref().unwrap());
+ commitment_signed_dance!(nodes[1], nodes[0], commitment_signed, false);
+ },
+ _ => panic!("Unexpected event"),
+ };
+
+ // However, if nodes[0] decreases their feerate, nodes[1] should reject it and close the
+ // channel.
+ {
+ let mut feerate_lock = chanmon_cfgs[0].fee_estimator.sat_per_kw.lock().unwrap();
+ *feerate_lock = 1000;
+ }
+ nodes[0].node.timer_tick_occurred();
+ check_added_monitors!(nodes[0], 1);
+
+ let events = nodes[0].node.get_and_clear_pending_msg_events();
+ assert_eq!(events.len(), 1);
+ match events[0] {
+ MessageSendEvent::UpdateHTLCs { updates: msgs::CommitmentUpdate { ref update_fee, .. }, .. } => {
+ nodes[1].node.handle_update_fee(&nodes[0].node.get_our_node_id(), update_fee.as_ref().unwrap());
+ check_closed_event!(nodes[1], 1, ClosureReason::ProcessingError {
+ err: "Peer's feerate much too low. Actual: 1000. Our expected lower limit: 5000 (- 250)".to_owned() });
+ check_closed_broadcast!(nodes[1], true);
+ check_added_monitors!(nodes[1], 1);
+ },
+ _ => panic!("Unexpected event"),
+ };
+}