Send failure event if we fail to handle a HTLC

In `ChannelManager::fail_htlc_backwards_internal`, we push a `HTLCHandlingFailed`
containing some information about the HTLC

fuzz/src/chanmon_consistency.rs

@@ -148,7 +148,7 @@ impl chain::Watch<EnforcingSigner> for TestChainMonitor {
 		self.chain_monitor.update_channel(funding_txo, update)
 	}
 
-	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>)> {
+	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)> {
 		return self.chain_monitor.release_pending_monitor_events();
 	}
 }

lightning/src/chain/chainmonitor.rs

@@ -43,6 +43,7 @@ use prelude::*;
 use sync::{RwLock, RwLockReadGuard, Mutex, MutexGuard};
 use core::ops::Deref;
 use core::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
+use bitcoin::secp256k1::PublicKey;
 
 #[derive(Clone, Copy, Hash, PartialEq, Eq)]
 /// A specific update's ID stored in a `MonitorUpdateId`, separated out to make the contents
@@ -235,7 +236,7 @@ pub struct ChainMonitor<ChannelSigner: Sign, C: Deref, T: Deref, F: Deref, L: De
 	persister: P,
 	/// "User-provided" (ie persistence-completion/-failed) [`MonitorEvent`]s. These came directly
 	/// from the user and not from a [`ChannelMonitor`].
-	pending_monitor_events: Mutex<Vec<(OutPoint, Vec<MonitorEvent>)>>,
+	pending_monitor_events: Mutex<Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>>,
 	/// The best block height seen, used as a proxy for the passage of time.
 	highest_chain_height: AtomicUsize,
 }
@@ -299,7 +300,7 @@ where C::Target: chain::Filter,
 							log_trace!(self.logger, "Finished syncing Channel Monitor for channel {}", log_funding_info!(monitor)),
 						Err(ChannelMonitorUpdateErr::PermanentFailure) => {
 							monitor_state.channel_perm_failed.store(true, Ordering::Release);
-							self.pending_monitor_events.lock().unwrap().push((*funding_outpoint, vec![MonitorEvent::UpdateFailed(*funding_outpoint)]));
+							self.pending_monitor_events.lock().unwrap().push((*funding_outpoint, vec![MonitorEvent::UpdateFailed(*funding_outpoint)], monitor.get_counterparty_node_id()));
 						},
 						Err(ChannelMonitorUpdateErr::TemporaryFailure) => {
 							log_debug!(self.logger, "Channel Monitor sync for channel {} in progress, holding events until completion!", log_funding_info!(monitor));
@@ -458,7 +459,7 @@ where C::Target: chain::Filter,
 				self.pending_monitor_events.lock().unwrap().push((funding_txo, vec![MonitorEvent::UpdateCompleted {
 					funding_txo,
 					monitor_update_id: monitor_data.monitor.get_latest_update_id(),
-				}]));
+				}], monitor_data.monitor.get_counterparty_node_id()));
 			},
 			MonitorUpdateId { contents: UpdateOrigin::ChainSync(_) } => {
 				if !monitor_data.has_pending_chainsync_updates(&pending_monitor_updates) {
@@ -476,10 +477,12 @@ where C::Target: chain::Filter,
 	/// channel_monitor_updated once with the highest ID.
 	#[cfg(any(test, fuzzing))]
 	pub fn force_channel_monitor_updated(&self, funding_txo: OutPoint, monitor_update_id: u64) {
+		let monitors = self.monitors.read().unwrap();
+		let counterparty_node_id = monitors.get(&funding_txo).and_then(|m| m.monitor.get_counterparty_node_id());
 		self.pending_monitor_events.lock().unwrap().push((funding_txo, vec![MonitorEvent::UpdateCompleted {
 			funding_txo,
 			monitor_update_id,
-		}]));
+		}], counterparty_node_id));
 	}
 
 	#[cfg(any(test, fuzzing, feature = "_test_utils"))]
@@ -666,7 +669,7 @@ where C::Target: chain::Filter,
 		}
 	}
 
-	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>)> {
+	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)> {
 		let mut pending_monitor_events = self.pending_monitor_events.lock().unwrap().split_off(0);
 		for monitor_state in self.monitors.read().unwrap().values() {
 			let is_pending_monitor_update = monitor_state.has_pending_chainsync_updates(&monitor_state.pending_monitor_updates.lock().unwrap());
@@ -695,7 +698,8 @@ where C::Target: chain::Filter,
 				let monitor_events = monitor_state.monitor.get_and_clear_pending_monitor_events();
 				if monitor_events.len() > 0 {
 					let monitor_outpoint = monitor_state.monitor.get_funding_txo().0;
-					pending_monitor_events.push((monitor_outpoint, monitor_events));
+					let counterparty_node_id = monitor_state.monitor.get_counterparty_node_id();
+					pending_monitor_events.push((monitor_outpoint, monitor_events, counterparty_node_id));
 				}
 			}
 		}

lightning/src/chain/channelmonitor.rs

@@ -1209,6 +1209,10 @@ impl<Signer: Sign> ChannelMonitor<Signer> {
 		self.inner.lock().unwrap().get_cur_holder_commitment_number()
 	}
 
+	pub(crate) fn get_counterparty_node_id(&self) -> Option<PublicKey> {
+		self.inner.lock().unwrap().counterparty_node_id
+	}
+
 	/// Used by ChannelManager deserialization to broadcast the latest holder state if its copy of
 	/// the Channel was out-of-date. You may use it to get a broadcastable holder toxic tx in case of
 	/// fallen-behind, i.e when receiving a channel_reestablish with a proof that our counterparty side knows

lightning/src/chain/mod.rs

@@ -15,6 +15,7 @@ use bitcoin::blockdata::script::Script;
 use bitcoin::blockdata::transaction::{Transaction, TxOut};
 use bitcoin::hash_types::{BlockHash, Txid};
 use bitcoin::network::constants::Network;
+use bitcoin::secp256k1::PublicKey;
 
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, MonitorEvent};
 use chain::keysinterface::Sign;
@@ -302,7 +303,7 @@ pub trait Watch<ChannelSigner: Sign> {
 	///
 	/// For details on asynchronous [`ChannelMonitor`] updating and returning
 	/// [`MonitorEvent::UpdateCompleted`] here, see [`ChannelMonitorUpdateErr::TemporaryFailure`].
-	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>)>;
+	fn release_pending_monitor_events(&self) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>;
 }
 
 /// The `Filter` trait defines behavior for indicating chain activity of interest pertaining to

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -26,7 +26,7 @@ use ln::msgs;
 use ln::msgs::{ChannelMessageHandler, RoutingMessageHandler};
 use util::config::UserConfig;
 use util::enforcing_trait_impls::EnforcingSigner;
-use util::events::{Event, MessageSendEvent, MessageSendEventsProvider, PaymentPurpose, ClosureReason};
+use util::events::{Event, MessageSendEvent, MessageSendEventsProvider, PaymentPurpose, ClosureReason, HTLCDestination};
 use util::errors::APIError;
 use util::ser::{ReadableArgs, Writeable};
 use util::test_utils::TestBroadcaster;
@@ -832,7 +832,7 @@ fn do_test_monitor_update_fail_raa(test_ignore_second_cs: bool) {
 
 	// Fail the payment backwards, failing the monitor update on nodes[1]'s receipt of the RAA
 	nodes[2].node.fail_htlc_backwards(&payment_hash_1);
-	expect_pending_htlcs_forwardable!(nodes[2]);
+	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[2], vec![HTLCDestination::FailedPayment { payment_hash: payment_hash_1 }]);
 	check_added_monitors!(nodes[2], 1);
 
 	let updates = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
@@ -913,7 +913,7 @@ fn do_test_monitor_update_fail_raa(test_ignore_second_cs: bool) {
 	let (outpoint, latest_update, _) = nodes[1].chain_monitor.latest_monitor_update_id.lock().unwrap().get(&chan_2.2).unwrap().clone();
 	nodes[1].chain_monitor.chain_monitor.force_channel_monitor_updated(outpoint, latest_update);
 	check_added_monitors!(nodes[1], 0);
-	expect_pending_htlcs_forwardable!(nodes[1]);
+	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[1], vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id: chan_2.2 }]);
 	check_added_monitors!(nodes[1], 1);
 
 	let mut events_3 = nodes[1].node.get_and_clear_pending_msg_events();
@@ -1690,14 +1690,14 @@ fn test_monitor_update_on_pending_forwards() {
 	let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
 	let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 	let chan_1 = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
-	create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
+	let chan_2 = create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
 
 	// Rebalance a bit so that we can send backwards from 3 to 1.
 	send_payment(&nodes[0], &[&nodes[1], &nodes[2]], 5000000);
 
 	let (_, payment_hash_1, _) = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 1000000);
 	nodes[2].node.fail_htlc_backwards(&payment_hash_1);
-	expect_pending_htlcs_forwardable!(nodes[2]);
+	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[2], vec![HTLCDestination::FailedPayment { payment_hash: payment_hash_1 }]);
 	check_added_monitors!(nodes[2], 1);
 
 	let cs_fail_update = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
@@ -1718,7 +1718,7 @@ fn test_monitor_update_on_pending_forwards() {
 	commitment_signed_dance!(nodes[1], nodes[2], payment_event.commitment_msg, false);
 
 	chanmon_cfgs[1].persister.set_update_ret(Err(ChannelMonitorUpdateErr::TemporaryFailure));
-	expect_pending_htlcs_forwardable!(nodes[1]);
+	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[1], vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id: chan_2.2 }]);
 	check_added_monitors!(nodes[1], 1);
 	assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
 	nodes[1].logger.assert_log("lightning::ln::channelmanager".to_string(), "Failed to update ChannelMonitor".to_string(), 1);
@@ -2106,7 +2106,7 @@ fn test_fail_htlc_on_broadcast_after_claim() {
 	check_closed_broadcast!(nodes[1], true);
 	connect_blocks(&nodes[1], ANTI_REORG_DELAY - 1);
 	check_added_monitors!(nodes[1], 1);
-	expect_pending_htlcs_forwardable!(nodes[1]);
+	expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[1], vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id: chan_id_2 }]);
 
 	nodes[0].node.handle_update_fulfill_htlc(&nodes[1].node.get_our_node_id(), &bs_updates.update_fulfill_htlcs[0]);
 	expect_payment_sent_without_paths!(nodes[0], payment_preimage);
@@ -2469,7 +2469,7 @@ fn do_test_reconnect_dup_htlc_claims(htlc_status: HTLCStatusAtDupClaim, second_f
 	};
 	if second_fails {
 		nodes[2].node.fail_htlc_backwards(&payment_hash);
-		expect_pending_htlcs_forwardable!(nodes[2]);
+		expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[2], vec![HTLCDestination::FailedPayment { payment_hash }]);
 		check_added_monitors!(nodes[2], 1);
 		get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
 	} else {
@@ -2505,7 +2505,7 @@ fn do_test_reconnect_dup_htlc_claims(htlc_status: HTLCStatusAtDupClaim, second_f
 
 	if second_fails {
 		reconnect_nodes(&nodes[1], &nodes[2], (false, false), (0, 0), (0, 0), (1, 0), (0, 0), (0, 0), (false, false));
-		expect_pending_htlcs_forwardable!(nodes[1]);
+		expect_pending_htlcs_forwardable_and_htlc_handling_failed!(nodes[1], vec![HTLCDestination::NextHopChannel { node_id: Some(nodes[2].node.get_our_node_id()), channel_id: chan_id_2 }]);
 	} else {
 		reconnect_nodes(&nodes[1], &nodes[2], (false, false), (0, 0), (1, 0), (0, 0), (0, 0), (0, 0), (false, false));
 	}

lightning/src/ln/channel.rs

@@ -5765,7 +5765,7 @@ impl<Signer: Sign> Channel<Signer> {
 	/// those explicitly stated to be allowed after shutdown completes, eg some simple getters).
 	/// Also returns the list of payment_hashes for channels which we can safely fail backwards
 	/// immediately (others we will have to allow to time out).
-	pub fn force_shutdown(&mut self, should_broadcast: bool) -> (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash)>) {
+	pub fn force_shutdown(&mut self, should_broadcast: bool) -> (Option<(OutPoint, ChannelMonitorUpdate)>, Vec<(HTLCSource, PaymentHash, PublicKey, [u8; 32])>) {
 		// Note that we MUST only generate a monitor update that indicates force-closure - we're
 		// called during initialization prior to the chain_monitor in the encompassing ChannelManager
 		// being fully configured in some cases. Thus, its likely any monitor events we generate will
@@ -5775,10 +5775,11 @@ impl<Signer: Sign> Channel<Signer> {
 		// We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and
 		// return them to fail the payment.
 		let mut dropped_outbound_htlcs = Vec::with_capacity(self.holding_cell_htlc_updates.len());
+		let counterparty_node_id = self.get_counterparty_node_id();
 		for htlc_update in self.holding_cell_htlc_updates.drain(..) {
 			match htlc_update {
 				HTLCUpdateAwaitingACK::AddHTLC { source, payment_hash, .. } => {
-					dropped_outbound_htlcs.push((source, payment_hash));
+					dropped_outbound_htlcs.push((source, payment_hash, counterparty_node_id, self.channel_id));
 				},
 				_ => {}
 			}