Fix handling RAA when a monitor update previously failed

Author: TheBlueMatt

src/ln/channelmanager.rs

@@ -161,6 +161,16 @@ impl MsgHandleErrInternal {
 		}
 	}
 	#[inline]
+	fn ignore_no_close(err: &'static str) -> Self {
+		Self {
+			err: HandleError {
+				err,
+				action: Some(msgs::ErrorAction::IgnoreError),
+			},
+			shutdown_finish: None,
+		}
+	}
+	#[inline]
 	fn from_no_close(err: msgs::HandleError) -> Self {
 		Self { err, shutdown_finish: None }
 	}
@@ -2030,10 +2040,16 @@ impl ChannelManager {
 						//TODO: here and below MsgHandleErrInternal, #153 case
 						return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id));
 					}
+					let was_frozen_for_monitor = chan.get().is_awaiting_monitor_update();
 					let (commitment_update, pending_forwards, pending_failures, closing_signed, chan_monitor) =
 						try_chan_entry!(self, chan.get_mut().revoke_and_ack(&msg, &*self.fee_estimator), channel_state, chan);
 					if let Err(e) = self.monitor.add_update_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) {
-						return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, commitment_update.is_some(), pending_forwards, pending_failures);
+						if was_frozen_for_monitor {
+							assert!(commitment_update.is_none() && closing_signed.is_none() && pending_forwards.is_empty() && pending_failures.is_empty());
+							return Err(MsgHandleErrInternal::ignore_no_close("Previous monitor update failure prevented responses to RAA"));
+						} else {
+							return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, commitment_update.is_some(), pending_forwards, pending_failures);
+						}
 					}
 					if let Some(updates) = commitment_update {
 						channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {

src/ln/functional_tests.rs

@@ -4595,6 +4595,75 @@ fn test_monitor_update_fail_no_rebroadcast() {
 	claim_payment(&nodes[0], &[&nodes[1]], payment_preimage_1);
 }
 
+#[test]
+fn test_monitor_update_raa_while_paused() {
+	// Tests handling of an RAA while monitor updating has already been marked failed.
+	// Backported from chanmon_fail_consistency fuzz tests as this used to be broken.
+	let mut nodes = create_network(2);
+	create_announced_chan_between_nodes(&nodes, 0, 1);
+
+	send_payment(&nodes[0], &[&nodes[1]], 5000000);
+
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &Vec::new(), 1000000, TEST_FINAL_CLTV).unwrap();
+	let (payment_preimage_1, our_payment_hash_1) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash_1).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let send_event_1 = SendEvent::from_event(nodes[0].node.get_and_clear_pending_msg_events().remove(0));
+
+	let route = nodes[1].router.get_route(&nodes[0].node.get_our_node_id(), None, &Vec::new(), 1000000, TEST_FINAL_CLTV).unwrap();
+	let (payment_preimage_2, our_payment_hash_2) = get_payment_preimage_hash!(nodes[0]);
+	nodes[1].node.send_payment(route, our_payment_hash_2).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	let send_event_2 = SendEvent::from_event(nodes[1].node.get_and_clear_pending_msg_events().remove(0));
+
+	nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &send_event_1.msgs[0]).unwrap();
+	nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &send_event_1.commitment_msg).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	let bs_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+	*nodes[0].chan_monitor.update_ret.lock().unwrap() = Err(ChannelMonitorUpdateErr::TemporaryFailure);
+	nodes[0].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &send_event_2.msgs[0]).unwrap();
+	if let msgs::HandleError { err, action: Some(msgs::ErrorAction::IgnoreError) } = nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &send_event_2.commitment_msg).unwrap_err() {
+		assert_eq!(err, "Failed to update ChannelMonitor");
+	} else { panic!(); }
+	check_added_monitors!(nodes[0], 1);
+
+	if let msgs::HandleError { err, action: Some(msgs::ErrorAction::IgnoreError) } = nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_raa).unwrap_err() {
+		assert_eq!(err, "Previous monitor update failure prevented responses to RAA");
+	} else { panic!(); }
+	check_added_monitors!(nodes[0], 1);
+
+	*nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(());
+	nodes[0].node.test_restore_channel_monitor();
+	check_added_monitors!(nodes[0], 1);
+
+	let as_update_raa = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_update_raa.0).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	let bs_cs = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+	nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_update_raa.1).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	let bs_second_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+	nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_cs.commitment_signed).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let as_second_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
+
+	nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_second_raa).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	expect_pending_htlcs_forwardable!(nodes[0]);
+	expect_payment_received!(nodes[0], our_payment_hash_2, 1000000);
+
+	nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_second_raa).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	expect_pending_htlcs_forwardable!(nodes[1]);
+	expect_payment_received!(nodes[1], our_payment_hash_1, 1000000);
+
+	claim_payment(&nodes[0], &[&nodes[1]], payment_preimage_1);
+	claim_payment(&nodes[1], &[&nodes[0]], payment_preimage_2);
+}
+
 fn do_test_monitor_update_fail_raa(test_ignore_second_cs: bool) {
 	// Tests handling of a monitor update failure when processing an incoming RAA
 	let mut nodes = create_network(3);