From 68be3c03531667a1ecae7c67664e0ef71ea98a61 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Fri, 14 Sep 2018 15:19:03 -0400 Subject: [PATCH 1/1] Test that we do not fail-backwards HTLCs that the remote on-chained --- src/ln/channelmanager.rs | 120 +++++++++++++++++++++++++++++++++++++++ src/ln/channelmonitor.rs | 3 + 2 files changed, 123 insertions(+) diff --git a/src/ln/channelmanager.rs b/src/ln/channelmanager.rs index 5bfe3688..765c417f 100644 --- a/src/ln/channelmanager.rs +++ b/src/ln/channelmanager.rs @@ -2198,6 +2198,7 @@ mod tests { use bitcoin::util::hash::Sha256dHash; use bitcoin::blockdata::block::{Block, BlockHeader}; use bitcoin::blockdata::transaction::{Transaction, TxOut}; + use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint; use bitcoin::blockdata::constants::genesis_block; use bitcoin::network::constants::Network; use bitcoin::network::serialize::serialize; @@ -3401,6 +3402,125 @@ mod tests { nodes[1].chain_monitor.block_connected_checked(&header, 1, &[&node_txn[0], &node_txn[1]], &[1; 2]); } + #[test] + fn test_force_close_fail_back() { + // Check which HTLCs are failed-backwards on channel force-closure + let mut nodes = create_network(3); + create_announced_chan_between_nodes(&nodes, 0, 1); + create_announced_chan_between_nodes(&nodes, 1, 2); + + let route = nodes[0].router.get_route(&nodes[2].node.get_our_node_id(), None, &Vec::new(), 1000000, 42).unwrap(); + + let our_payment_preimage = [*nodes[0].network_payment_count.borrow(); 32]; + *nodes[0].network_payment_count.borrow_mut() += 1; + let our_payment_hash = { + let mut sha = Sha256::new(); + sha.input(&our_payment_preimage[..]); + let mut ret = [0; 32]; + sha.result(&mut ret); + ret + }; + + let mut payment_event = { + nodes[0].node.send_payment(route, our_payment_hash).unwrap(); + { + let mut added_monitors = nodes[0].chan_monitor.added_monitors.lock().unwrap(); + assert_eq!(added_monitors.len(), 1); + added_monitors.clear(); + } + + let mut events = nodes[0].node.get_and_clear_pending_events(); + assert_eq!(events.len(), 1); + SendEvent::from_event(events.remove(0)) + }; + + nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]).unwrap(); + commitment_signed_dance!(nodes[1], nodes[0], payment_event.commitment_msg, false); + + let events_1 = nodes[1].node.get_and_clear_pending_events(); + assert_eq!(events_1.len(), 1); + match events_1[0] { + Event::PendingHTLCsForwardable { .. } => { }, + _ => panic!("Unexpected event"), + }; + + nodes[1].node.channel_state.lock().unwrap().next_forward = Instant::now(); + nodes[1].node.process_pending_htlc_forwards(); + + let mut events_2 = nodes[1].node.get_and_clear_pending_events(); + assert_eq!(events_2.len(), 1); + payment_event = SendEvent::from_event(events_2.remove(0)); + assert_eq!(payment_event.msgs.len(), 1); + + { + let mut added_monitors = nodes[1].chan_monitor.added_monitors.lock().unwrap(); + assert_eq!(added_monitors.len(), 1); + added_monitors.clear(); + } + + nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &payment_event.msgs[0]).unwrap(); + nodes[2].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &payment_event.commitment_msg).unwrap(); + + { + let mut added_monitors = nodes[2].chan_monitor.added_monitors.lock().unwrap(); + assert_eq!(added_monitors.len(), 1); + added_monitors.clear(); + } + + // nodes[2] now has the latest commitment transaction, but hasn't revoked its previous + // state or updated nodes[1]' state. Now force-close and broadcast that commitment/HTLC + // transaction and ensure nodes[1] doesn't fail-backwards (this was originally a bug!). + + nodes[2].node.force_close_channel(&payment_event.commitment_msg.channel_id); + let events_3 = nodes[2].node.get_and_clear_pending_events(); + assert_eq!(events_3.len(), 1); + match events_3[0] { + Event::BroadcastChannelUpdate { msg: msgs::ChannelUpdate { contents: msgs::UnsignedChannelUpdate { flags, .. }, .. } } => { + assert_eq!(flags & 0b10, 0b10); + }, + _ => panic!("Unexpected event"), + } + + let tx = { + let mut node_txn = nodes[2].tx_broadcaster.txn_broadcasted.lock().unwrap(); + // Note that we don't bother broadcasting the HTLC-Success transaction here as we don't + // have a use for it unless nodes[2] learns the preimage somehow, the funds will go + // back to nodes[1] upon timeout otherwise. + assert_eq!(node_txn.len(), 1); + node_txn.remove(0) + }; + + let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42 }; + nodes[1].chain_monitor.block_connected_checked(&header, 1, &[&tx], &[1]); + + let events_4 = nodes[1].node.get_and_clear_pending_events(); + // Note no UpdateHTLCs event here from nodes[1] to nodes[0]! + assert_eq!(events_4.len(), 1); + match events_4[0] { + Event::BroadcastChannelUpdate { msg: msgs::ChannelUpdate { contents: msgs::UnsignedChannelUpdate { flags, .. }, .. } } => { + assert_eq!(flags & 0b10, 0b10); + }, + _ => panic!("Unexpected event"), + } + + // Now check that if we add the preimage to ChannelMonitor it broadcasts our HTLC-Success.. + { + let mut monitors = nodes[2].chan_monitor.simple_monitor.monitors.lock().unwrap(); + monitors.get_mut(&OutPoint::new(Sha256dHash::from(&payment_event.commitment_msg.channel_id[..]), 0)).unwrap() + .provide_payment_preimage(&our_payment_hash, &our_payment_preimage); + } + nodes[2].chain_monitor.block_connected_checked(&header, 1, &[&tx], &[1]); + let node_txn = nodes[2].tx_broadcaster.txn_broadcasted.lock().unwrap(); + assert_eq!(node_txn.len(), 1); + assert_eq!(node_txn[0].input.len(), 1); + assert_eq!(node_txn[0].input[0].previous_output.txid, tx.txid()); + assert_eq!(node_txn[0].lock_time, 0); // Must be an HTLC-Success + assert_eq!(node_txn[0].input[0].witness.len(), 5); // Must be an HTLC-Success + let mut funding_tx_map = HashMap::new(); + funding_tx_map.insert(tx.txid(), tx); + node_txn[0].verify(&funding_tx_map).unwrap(); + } + #[test] fn test_unconf_chan() { // After creating a chan between nodes, we disconnect all blocks previously seen to force a channel close on nodes[0] side diff --git a/src/ln/channelmonitor.rs b/src/ln/channelmonitor.rs index 55e534c8..ded2a99d 100644 --- a/src/ln/channelmonitor.rs +++ b/src/ln/channelmonitor.rs @@ -63,6 +63,9 @@ pub trait ManyChannelMonitor: Send + Sync { /// If you're using this for local monitoring of your own channels, you probably want to use /// `OutPoint` as the key, which will give you a ManyChannelMonitor implementation. pub struct SimpleManyChannelMonitor { + #[cfg(test)] // Used in ChannelManager tests to manipulate channels directly + pub monitors: Mutex>, + #[cfg(not(test))] monitors: Mutex>, chain_monitor: Arc, broadcaster: Arc -- 2.30.2