Test pending payments when duplicatively resolved on chain
authorMatt Corallo <git@bluematt.me>
Sat, 8 May 2021 22:54:26 +0000 (22:54 +0000)
committerMatt Corallo <git@bluematt.me>
Thu, 20 May 2021 16:30:27 +0000 (16:30 +0000)
lightning/src/ln/functional_tests.rs

index 10270e68a92ad3a4c45e1a4ca4104ae7b18b00b0..929dd901abb05d82086ceaa4fc6d1904ab7750c8 100644 (file)
@@ -4302,6 +4302,108 @@ fn test_no_txn_manager_serialize_deserialize() {
        send_payment(&nodes[0], &[&nodes[1]], 1000000);
 }
 
+#[test]
+fn test_dup_htlc_onchain_fails_on_reload() {
+       // When a Channel is closed, any outbound HTLCs which were relayed through it are simply
+       // dropped when the Channel is. From there, the ChannelManager relies on the ChannelMonitor
+       // having a copy of the relevant fail-/claim-back data and processes the HTLC fail/claim when
+       // the ChannelMonitor tells it to.
+       //
+       // If, due to an on-chain event, an HTLC is failed/claimed, and then we serialize the
+       // ChannelManager, we generally expect there not to be a duplicate HTLC fail/claim (eg via a
+       // PaymentFailed event appearing). However, because we may not serialize the relevant
+       // ChannelMonitor at the same time, this isn't strictly guaranteed. In order to provide this
+       // consistency, the ChannelManager explicitly tracks pending-onchain-resolution outbound HTLCs
+       // and de-duplicates ChannelMonitor events.
+       //
+       // This tests that explicit tracking behavior.
+       let 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 persister: test_utils::TestPersister;
+       let new_chain_monitor: test_utils::TestChainMonitor;
+       let nodes_0_deserialized: ChannelManager<EnforcingSigner, &test_utils::TestChainMonitor, &test_utils::TestBroadcaster, &test_utils::TestKeysInterface, &test_utils::TestFeeEstimator, &test_utils::TestLogger>;
+       let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+       create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
+
+       // Route a payment, but force-close the channel before the HTLC fulfill message arrives at
+       // nodes[0].
+       let (payment_preimage, _, _) = route_payment(&nodes[0], &[&nodes[1]], 10000000);
+       nodes[0].node.force_close_channel(&nodes[0].node.list_channels()[0].channel_id).unwrap();
+       check_closed_broadcast!(nodes[0], true);
+       check_added_monitors!(nodes[0], 1);
+
+       nodes[0].node.peer_disconnected(&nodes[1].node.get_our_node_id(), false);
+       nodes[1].node.peer_disconnected(&nodes[0].node.get_our_node_id(), false);
+
+       let node_txn = nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+       assert_eq!(node_txn.len(), 2);
+
+       assert!(nodes[1].node.claim_funds(payment_preimage));
+       check_added_monitors!(nodes[1], 1);
+
+       let mut header = BlockHeader { version: 0x20000000, prev_blockhash: nodes[1].best_block_hash(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 };
+       connect_block(&nodes[1], &Block { header, txdata: vec![node_txn[0].clone(), node_txn[1].clone()]});
+       check_closed_broadcast!(nodes[1], true);
+       check_added_monitors!(nodes[1], 1);
+       let claim_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
+
+       connect_block(&nodes[0], &Block { header, txdata: node_txn});
+
+       // Serialize out the ChannelMonitor before connecting the on-chain claim transactions. This is
+       // fairly normal behavior as ChannelMonitor(s) are often not re-serialized when on-chain events
+       // happen, unlike ChannelManager which tends to be re-serialized after any relevant event(s).
+       let mut chan_0_monitor_serialized = test_utils::TestVecWriter(Vec::new());
+       nodes[0].chain_monitor.chain_monitor.monitors.read().unwrap().iter().next().unwrap().1.write(&mut chan_0_monitor_serialized).unwrap();
+
+       header.prev_blockhash = header.block_hash();
+       let claim_block = Block { header, txdata: claim_txn};
+       connect_block(&nodes[0], &claim_block);
+       expect_payment_sent!(nodes[0], payment_preimage);
+
+       // ChannelManagers generally get re-serialized after any relevant event(s). Since we just
+       // connected a highly-relevant block, it likely gets serialized out now.
+       let mut chan_manager_serialized = test_utils::TestVecWriter(Vec::new());
+       nodes[0].node.write(&mut chan_manager_serialized).unwrap();
+
+       // Now reload nodes[0]...
+       persister = test_utils::TestPersister::new();
+       let keys_manager = &chanmon_cfgs[0].keys_manager;
+       new_chain_monitor = test_utils::TestChainMonitor::new(Some(nodes[0].chain_source), nodes[0].tx_broadcaster.clone(), nodes[0].logger, node_cfgs[0].fee_estimator, &persister, keys_manager);
+       nodes[0].chain_monitor = &new_chain_monitor;
+       let mut chan_0_monitor_read = &chan_0_monitor_serialized.0[..];
+       let (_, mut chan_0_monitor) = <(BlockHash, ChannelMonitor<EnforcingSigner>)>::read(
+               &mut chan_0_monitor_read, keys_manager).unwrap();
+       assert!(chan_0_monitor_read.is_empty());
+
+       let (_, nodes_0_deserialized_tmp) = {
+               let mut channel_monitors = HashMap::new();
+               channel_monitors.insert(chan_0_monitor.get_funding_txo().0, &mut chan_0_monitor);
+               <(BlockHash, ChannelManager<EnforcingSigner, &test_utils::TestChainMonitor, &test_utils::TestBroadcaster, &test_utils::TestKeysInterface, &test_utils::TestFeeEstimator, &test_utils::TestLogger>)>
+                       ::read(&mut std::io::Cursor::new(&chan_manager_serialized.0[..]), ChannelManagerReadArgs {
+                               default_config: Default::default(),
+                               keys_manager,
+                               fee_estimator: node_cfgs[0].fee_estimator,
+                               chain_monitor: nodes[0].chain_monitor,
+                               tx_broadcaster: nodes[0].tx_broadcaster.clone(),
+                               logger: nodes[0].logger,
+                               channel_monitors,
+                       }).unwrap()
+       };
+       nodes_0_deserialized = nodes_0_deserialized_tmp;
+
+       assert!(nodes[0].chain_monitor.watch_channel(chan_0_monitor.get_funding_txo().0, chan_0_monitor).is_ok());
+       check_added_monitors!(nodes[0], 1);
+       nodes[0].node = &nodes_0_deserialized;
+
+       // Note that if we re-connect the block which exposed nodes[0] to the payment preimage (but
+       // which the current ChannelMonitor has not seen), the ChannelManager's de-duplication of
+       // payment events should kick in, leaving us with no pending events here.
+       nodes[0].chain_monitor.chain_monitor.block_connected(&claim_block, nodes[0].blocks.borrow().len() as u32 - 1);
+       assert!(nodes[0].node.get_and_clear_pending_events().is_empty());
+}
+
 #[test]
 fn test_manager_serialize_deserialize_events() {
        // This test makes sure the events field in ChannelManager survives de/serialization