From: Matt Corallo Date: Sat, 8 May 2021 22:54:26 +0000 (+0000) Subject: Test new ChannelManager tracking of outbound pending onchain HTLCs X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=refs%2Fheads%2F2021-05-dup-onchain-claims;p=rust-lightning Test new ChannelManager tracking of outbound pending onchain HTLCs --- diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs index 4a94b6c6e..efc2c872c 100644 --- a/lightning/src/ln/functional_tests.rs +++ b/lightning/src/ln/functional_tests.rs @@ -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; + 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)>::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)> + ::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