Add test for partial-send MPP due to monitor update failure

Relatively simple test that, after a monitor update fails, we get
the right return value and continue with the bits of the MPP that
did not send after the monitor updating is restored.

diff --git a/lightning/src/ln/chanmon_update_fail_tests.rs b/lightning/src/ln/chanmon_update_fail_tests.rs
index 5d8c47377c704ebbef183669afff6dd467407340..4cce9fcd2cd4e00f18043d823472679ba061c796 100644 (file)
--- a/lightning/src/ln/chanmon_update_fail_tests.rs
+++ b/lightning/src/ln/chanmon_update_fail_tests.rs
@@ -4,7 +4,7 @@
 //! here. See also the chanmon_fail_consistency fuzz test.
 
 use chain::transaction::OutPoint;
-use ln::channelmanager::{RAACommitmentOrder, PaymentPreimage, PaymentHash, PaymentSendFailure};
+use ln::channelmanager::{RAACommitmentOrder, PaymentPreimage, PaymentHash, PaymentSecret, PaymentSendFailure};
 use ln::channelmonitor::ChannelMonitorUpdateErr;
 use ln::features::InitFeatures;
 use ln::msgs;
@@ -1731,3 +1731,63 @@ fn during_funding_monitor_fail() {
        do_during_funding_monitor_fail(true, false);
        do_during_funding_monitor_fail(false, false);
 }
+
+#[test]
+fn test_path_paused_mpp() {
+       // Simple test of sending a multi-part payment where one path is currently blocked awaiting
+       // monitor update
+       let chanmon_cfgs = create_chanmon_cfgs(4);
+       let node_cfgs = create_node_cfgs(4, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
+       let mut nodes = create_network(4, &node_cfgs, &node_chanmgrs);
+
+       let chan_1_id = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::supported(), InitFeatures::supported()).0.contents.short_channel_id;
+       let (chan_2_ann, _, chan_2_id, _) = create_announced_chan_between_nodes(&nodes, 0, 2, InitFeatures::supported(), InitFeatures::supported());
+       let chan_3_id = create_announced_chan_between_nodes(&nodes, 1, 3, InitFeatures::supported(), InitFeatures::supported()).0.contents.short_channel_id;
+       let chan_4_id = create_announced_chan_between_nodes(&nodes, 2, 3, InitFeatures::supported(), InitFeatures::supported()).0.contents.short_channel_id;
+
+       let (payment_preimage, payment_hash) = get_payment_preimage_hash!(&nodes[0]);
+       let payment_secret = PaymentSecret([0xdb; 32]);
+       let mut route = nodes[0].router.get_route(&nodes[3].node.get_our_node_id(), None, &[], 100000, TEST_FINAL_CLTV).unwrap();
+
+       // Set us up to take multiple routes, one 0 -> 1 -> 3 and one 0 -> 2 -> 3:
+       let path = route.paths[0].clone();
+       route.paths.push(path);
+       route.paths[0][0].pubkey = nodes[1].node.get_our_node_id();
+       route.paths[0][0].short_channel_id = chan_1_id;
+       route.paths[0][1].short_channel_id = chan_3_id;
+       route.paths[1][0].pubkey = nodes[2].node.get_our_node_id();
+       route.paths[1][0].short_channel_id = chan_2_ann.contents.short_channel_id;
+       route.paths[1][1].short_channel_id = chan_4_id;
+
+       // Set it so that the first monitor update (for the path 0 -> 1 -> 3) succeeds, but the second
+       // (for the path 0 -> 2 -> 3) fails.
+       *nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(());
+       *nodes[0].chan_monitor.next_update_ret.lock().unwrap() = Some(Err(ChannelMonitorUpdateErr::TemporaryFailure));
+
+       // Now check that we get the right return value, indicating that the first path succeeded but
+       // the second got a MonitorUpdateFailed err. This implies PaymentSendFailure::PartialFailure as
+       // some paths succeeded, preventing retry.
+       if let Err(PaymentSendFailure::PartialFailure(results)) = nodes[0].node.send_payment(&route, payment_hash, &Some(payment_secret)) {
+               assert_eq!(results.len(), 2);
+               if let Ok(()) = results[0] {} else { panic!(); }
+               if let Err(APIError::MonitorUpdateFailed) = results[1] {} else { panic!(); }
+       } else { panic!(); }
+       check_added_monitors!(nodes[0], 2);
+       *nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(());
+
+       // Pass the first HTLC of the payment along to nodes[3].
+       let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 1);
+       pass_along_path(&nodes[0], &[&nodes[1], &nodes[3]], 0, payment_hash.clone(), Some(payment_secret), events.pop().unwrap(), false);
+
+       // And check that, after we successfully update the monitor for chan_2 we can pass the second
+       // HTLC along to nodes[3] and claim the whole payment back to nodes[0].
+       let (outpoint, latest_update) = nodes[0].chan_monitor.latest_monitor_update_id.lock().unwrap().get(&chan_2_id).unwrap().clone();
+       nodes[0].node.channel_monitor_updated(&outpoint, latest_update);
+       let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 1);
+       pass_along_path(&nodes[0], &[&nodes[2], &nodes[3]], 200_000, payment_hash.clone(), Some(payment_secret), events.pop().unwrap(), true);
+
+       claim_payment_along_route_with_secret(&nodes[0], &[&[&nodes[1], &nodes[3]], &[&nodes[2], &nodes[3]]], false, payment_preimage, Some(payment_secret), 200_000);
+}

diff --git a/lightning/src/util/test_utils.rs b/lightning/src/util/test_utils.rs
index 4fcaf803e7e7071ec9d17007e65920cf1e4fcd01..905a53e6648c247022f7163c4d98819394b307e9 100644 (file)
--- a/lightning/src/util/test_utils.rs
+++ b/lightning/src/util/test_utils.rs
@@ -51,6 +51,9 @@ pub struct TestChannelMonitor<'a> {
        pub latest_monitor_update_id: Mutex<HashMap<[u8; 32], (OutPoint, u64)>>,
        pub simple_monitor: channelmonitor::SimpleManyChannelMonitor<OutPoint, EnforcingChannelKeys, &'a chaininterface::BroadcasterInterface, &'a TestFeeEstimator>,
        pub update_ret: Mutex<Result<(), channelmonitor::ChannelMonitorUpdateErr>>,
+       // If this is set to Some(), after the next return, we'll always return this until update_ret
+       // is changed:
+       pub next_update_ret: Mutex<Option<Result<(), channelmonitor::ChannelMonitorUpdateErr>>>,
 }
 impl<'a> TestChannelMonitor<'a> {
        pub fn new(chain_monitor: Arc<chaininterface::ChainWatchInterface>, broadcaster: &'a chaininterface::BroadcasterInterface, logger: Arc<Logger>, fee_estimator: &'a TestFeeEstimator) -> Self {
@@ -59,6 +62,7 @@ impl<'a> TestChannelMonitor<'a> {
                        latest_monitor_update_id: Mutex::new(HashMap::new()),
                        simple_monitor: channelmonitor::SimpleManyChannelMonitor::new(chain_monitor, broadcaster, logger, fee_estimator),
                        update_ret: Mutex::new(Ok(())),
+                       next_update_ret: Mutex::new(None),
                }
        }
 }
@@ -74,7 +78,12 @@ impl<'a> channelmonitor::ManyChannelMonitor<EnforcingChannelKeys> for TestChanne
                self.latest_monitor_update_id.lock().unwrap().insert(funding_txo.to_channel_id(), (funding_txo, monitor.get_latest_update_id()));
                self.added_monitors.lock().unwrap().push((funding_txo, monitor));
                assert!(self.simple_monitor.add_monitor(funding_txo, new_monitor).is_ok());
-               self.update_ret.lock().unwrap().clone()
+
+               let ret = self.update_ret.lock().unwrap().clone();
+               if let Some(next_ret) = self.next_update_ret.lock().unwrap().take() {
+                       *self.update_ret.lock().unwrap() = next_ret;
+               }
+               ret
        }
 
        fn update_monitor(&self, funding_txo: OutPoint, update: channelmonitor::ChannelMonitorUpdate) -> Result<(), channelmonitor::ChannelMonitorUpdateErr> {
@@ -96,7 +105,12 @@ impl<'a> channelmonitor::ManyChannelMonitor<EnforcingChannelKeys> for TestChanne
                                &mut ::std::io::Cursor::new(&w.0), Arc::new(TestLogger::new())).unwrap().1;
                assert!(new_monitor == *monitor);
                self.added_monitors.lock().unwrap().push((funding_txo, new_monitor));
-               self.update_ret.lock().unwrap().clone()
+
+               let ret = self.update_ret.lock().unwrap().clone();
+               if let Some(next_ret) = self.next_update_ret.lock().unwrap().take() {
+                       *self.update_ret.lock().unwrap() = next_ret;
+               }
+               ret
        }
 
        fn get_and_clear_pending_htlcs_updated(&self) -> Vec<HTLCUpdate> {