Accept feerate increases even if they aren't high enough for us

[rust-lightning] / lightning / src / ln / functional_tests.rs

diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs
index b95356a3dd7aa8b7375118612fe2faa3c2a8b2e7..f9b9e75bf6d8d4385691f11f5ab5a86830030e9a 100644 (file)
--- a/lightning/src/ln/functional_tests.rs
+++ b/lightning/src/ln/functional_tests.rs
@@ -10490,3 +10490,81 @@ fn test_non_final_funding_tx() {
        assert!(nodes[0].node.funding_transaction_generated(&temp_channel_id, &nodes[1].node.get_our_node_id(), tx.clone()).is_ok());
        get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id());
 }
+
+#[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"),
+       };
+}