Add ChannelDataPersister trait and integrate in ChainMonitor.

The ChannelDataPersister is responsible for loading ChannelMonitors
from disk on startup, and persisting new ChannelMonitors and
ChannelMonitor updates.

Author: valentinewallace

fuzz/src/chanmon_consistency.rs

@@ -35,6 +35,7 @@ use lightning::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr,
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::keysinterface::{KeysInterface, InMemoryChannelKeys};
+use lightning::ln::data_persister::ChannelDataPersister;
 use lightning::ln::channelmanager::{ChannelManager, PaymentHash, PaymentPreimage, PaymentSecret, ChannelManagerReadArgs};
 use lightning::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
 use lightning::ln::msgs::{CommitmentUpdate, ChannelMessageHandler, ErrorAction, UpdateAddHTLC, Init};
@@ -48,6 +49,7 @@ use lightning::routing::router::{Route, RouteHop};
 
 
 use utils::test_logger;
+use utils::test_data_persister::TestChanDataPersister;
 
 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
 use bitcoin::secp256k1::Secp256k1;
@@ -84,7 +86,7 @@ impl Writer for VecWriter {
 
 struct TestChainMonitor {
 	pub logger: Arc<dyn Logger>,
-	pub chain_monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	pub chain_monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	pub update_ret: Mutex<Result<(), channelmonitor::ChannelMonitorUpdateErr>>,
 	// If we reload a node with an old copy of ChannelMonitors, the ChannelManager deserialization
 	// logic will automatically force-close our channels for us (as we don't have an up-to-date
@@ -95,9 +97,9 @@ struct TestChainMonitor {
 	pub should_update_manager: atomic::AtomicBool,
 }
 impl TestChainMonitor {
-	pub fn new(broadcaster: Arc<TestBroadcaster>, logger: Arc<dyn Logger>, feeest: Arc<FuzzEstimator>) -> Self {
+	pub fn new(broadcaster: Arc<TestBroadcaster>, logger: Arc<dyn Logger>, feeest: Arc<FuzzEstimator>, data_persister: Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>) -> Self {
 		Self {
-			chain_monitor: Arc::new(channelmonitor::ChainMonitor::new(None, broadcaster, logger.clone(), feeest)),
+			chain_monitor: Arc::new(channelmonitor::ChainMonitor::new(None, broadcaster, logger.clone(), feeest, data_persister).unwrap()),
 			logger,
 			update_ret: Mutex::new(Ok(())),
 			latest_monitors: Mutex::new(HashMap::new()),
@@ -127,7 +129,7 @@ impl chain::Watch for TestChainMonitor {
 		};
 		let mut deserialized_monitor = <(BlockHash, channelmonitor::ChannelMonitor<EnforcingChannelKeys>)>::
 			read(&mut Cursor::new(&map_entry.get().1)).unwrap().1;
-		deserialized_monitor.update_monitor(update.clone(), &&TestBroadcaster {}, &self.logger).unwrap();
+		deserialized_monitor.update_monitor(&update, &&TestBroadcaster {}, &self.logger).unwrap();
 		let mut ser = VecWriter(Vec::new());
 		deserialized_monitor.write_for_disk(&mut ser).unwrap();
 		map_entry.insert((update.update_id, ser.0));
@@ -192,7 +194,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 	macro_rules! make_node {
 		($node_id: expr) => { {
 			let logger: Arc<dyn Logger> = Arc::new(test_logger::TestLogger::new($node_id.to_string(), out.clone()));
-			let monitor = Arc::new(TestChainMonitor::new(broadcast.clone(), logger.clone(), fee_est.clone()));
+			let data_persister = Arc::new(TestChanDataPersister{});
+			let monitor = Arc::new(TestChainMonitor::new(broadcast.clone(), logger.clone(), fee_est.clone(), data_persister.clone()));
 
 			let keys_manager = Arc::new(KeyProvider { node_id: $node_id, rand_bytes_id: atomic::AtomicU8::new(0) });
 			let mut config = UserConfig::default();
@@ -207,7 +210,8 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 	macro_rules! reload_node {
 		($ser: expr, $node_id: expr, $old_monitors: expr) => { {
 			let logger: Arc<dyn Logger> = Arc::new(test_logger::TestLogger::new($node_id.to_string(), out.clone()));
-			let chain_monitor = Arc::new(TestChainMonitor::new(broadcast.clone(), logger.clone(), fee_est.clone()));
+			let data_persister = Arc::new(TestChanDataPersister{});
+			let chain_monitor = Arc::new(TestChainMonitor::new(broadcast.clone(), logger.clone(), fee_est.clone(), data_persister.clone()));
 
 			let keys_manager = Arc::new(KeyProvider { node_id: $node_id, rand_bytes_id: atomic::AtomicU8::new(0) });
 			let mut config = UserConfig::default();

fuzz/src/full_stack.rs

@@ -31,6 +31,7 @@ use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget,
 use lightning::chain::channelmonitor;
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::keysinterface::{InMemoryChannelKeys, KeysInterface};
+use lightning::ln::data_persister::ChannelDataPersister;
 use lightning::ln::channelmanager::{ChannelManager, PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::ln::peer_handler::{MessageHandler,PeerManager,SocketDescriptor};
 use lightning::routing::router::get_route;
@@ -41,6 +42,7 @@ use lightning::util::logger::Logger;
 use lightning::util::config::UserConfig;
 
 use utils::test_logger;
+use utils::test_data_persister::TestChanDataPersister;
 
 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
 use bitcoin::secp256k1::Secp256k1;
@@ -146,13 +148,13 @@ impl<'a> std::hash::Hash for Peer<'a> {
 
 type ChannelMan = ChannelManager<
 	EnforcingChannelKeys,
-	Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	Arc<TestBroadcaster>, Arc<KeyProvider>, Arc<FuzzEstimator>, Arc<dyn Logger>>;
 type PeerMan<'a> = PeerManager<Peer<'a>, Arc<ChannelMan>, Arc<NetGraphMsgHandler<Arc<dyn chain::Access>, Arc<dyn Logger>>>, Arc<dyn Logger>>;
 
 struct MoneyLossDetector<'a> {
 	manager: Arc<ChannelMan>,
-	monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	handler: PeerMan<'a>,
 
 	peers: &'a RefCell<[bool; 256]>,
@@ -166,7 +168,7 @@ struct MoneyLossDetector<'a> {
 impl<'a> MoneyLossDetector<'a> {
 	pub fn new(peers: &'a RefCell<[bool; 256]>,
 	           manager: Arc<ChannelMan>,
-	           monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	           monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Notify>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	           handler: PeerMan<'a>) -> Self {
 		MoneyLossDetector {
 			manager,
@@ -334,7 +336,8 @@ pub fn do_test(data: &[u8], logger: &Arc<dyn Logger>) {
 	};
 
 	let broadcast = Arc::new(TestBroadcaster{});
-	let monitor = Arc::new(channelmonitor::ChainMonitor::new(None, broadcast.clone(), Arc::clone(&logger), fee_est.clone()));
+	let data_persister: Arc<dyn ChannelDataPersister<Keys = EnforcingChannelKeys>> = Arc::new(TestChanDataPersister{});
+	let monitor = Arc::new(channelmonitor::ChainMonitor::new(None, broadcast.clone(), Arc::clone(&logger), fee_est.clone(), data_persister.clone()).unwrap());
 
 	let keys_manager = Arc::new(KeyProvider { node_secret: our_network_key.clone(), counter: AtomicU64::new(0) });
 	let mut config = UserConfig::default();

fuzz/src/utils/mod.rs

@@ -8,3 +8,4 @@
 // licenses.
 
 pub mod test_logger;
+pub mod test_data_persister;

fuzz/src/utils/test_data_persister.rs

@@ -0,0 +1,23 @@
+use lightning::ln::data_persister::ChannelDataPersister;
+use lightning::chain::channelmonitor;
+use lightning::chain::transaction::OutPoint;
+use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
+
+use std::collections::HashMap;
+
+pub struct TestChanDataPersister {}
+impl ChannelDataPersister for TestChanDataPersister {
+	type Keys = EnforcingChannelKeys;
+
+	fn persist_channel_data(&self, _funding_txo: OutPoint, _data: &channelmonitor::ChannelMonitor<EnforcingChannelKeys>) -> Result<(), channelmonitor::ChannelMonitorUpdateErr> {
+		Ok(())
+	}
+
+	fn update_channel_data(&self, _funding_txo: OutPoint, _update: &channelmonitor::ChannelMonitorUpdate, _data: &channelmonitor::ChannelMonitor<EnforcingChannelKeys>) -> Result<(), channelmonitor::ChannelMonitorUpdateErr> {
+		Ok(())
+	}
+
+	fn load_channel_data(&self) -> Result<HashMap<OutPoint, channelmonitor::ChannelMonitor<EnforcingChannelKeys>>, channelmonitor::ChannelMonitorUpdateErr> {
+		Ok(HashMap::new())
+	}
+}

lightning-net-tokio/src/lib.rs

@@ -36,7 +36,8 @@
 //! type Logger = dyn lightning::util::logger::Logger;
 //! type ChainAccess = dyn lightning::chain::Access;
 //! type ChainNotify = dyn lightning::chain::Notify;
-//! type ChainMonitor = lightning::chain::channelmonitor::ChainMonitor<lightning::chain::keysinterface::InMemoryChannelKeys, Arc<ChainNotify>, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>>;
+//! type DataPersister = dyn lightning::ln::data_persister::ChannelDataPersister<Keys = lightning::chain::keysinterface::InMemoryChannelKeys>;
+//! type ChainMonitor = lightning::chain::channelmonitor::ChainMonitor<lightning::chain::keysinterface::InMemoryChannelKeys, Arc<ChainNotify>, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>, Arc<DataPersister>>;
 //! type ChannelManager = lightning::ln::channelmanager::SimpleArcChannelManager<ChainMonitor, TxBroadcaster, FeeEstimator, Logger>;
 //! type PeerManager = lightning::ln::peer_handler::SimpleArcPeerManager<lightning_net_tokio::SocketDescriptor, ChainMonitor, TxBroadcaster, FeeEstimator, ChainAccess, Logger>;
 //!

lightning/src/chain/channelmonitor.rs

@@ -43,6 +43,7 @@ use ln::chan_utils;
 use ln::chan_utils::{CounterpartyCommitmentSecrets, HTLCOutputInCommitment, LocalCommitmentTransaction, HTLCType};
 use ln::channelmanager::{HTLCSource, PaymentPreimage, PaymentHash};
 use ln::onchaintx::{OnchainTxHandler, InputDescriptors};
+use ln::data_persister::ChannelDataPersister;
 use chain;
 use chain::Notify;
 use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
@@ -99,7 +100,7 @@ impl Readable for ChannelMonitorUpdate {
 }
 
 /// An error enum representing a failure to persist a channel monitor update.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum ChannelMonitorUpdateErr {
 	/// Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
 	/// our state failed, but is expected to succeed at some point in the future).
@@ -182,25 +183,28 @@ impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
 /// independently to monitor channels remotely.
 ///
 /// [`chain::Watch`]: ../../chain/trait.Watch.html
-pub struct ChainMonitor<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref>
+pub struct ChainMonitor<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, D: Deref>
 	where C::Target: chain::Notify,
         T::Target: BroadcasterInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
+        D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	/// The monitors
 	pub monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
 	chain_source: Option<C>,
 	broadcaster: T,
 	logger: L,
-	fee_estimator: F
+	fee_estimator: F,
+	data_persister: D,
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, C, T, F, L>
+impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, D: Deref> ChainMonitor<ChanSigner, C, T, F, L, D>
 	where C::Target: chain::Notify,
 	      T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
+        D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	/// Dispatches to per-channel monitors, which are responsible for updating their on-chain view
 	/// of a channel and reacting accordingly based on transactions in the connected block. See
@@ -246,22 +250,29 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 	}
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, C, T, F, L>
+impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, D: Deref> ChainMonitor<ChanSigner, C, T, F, L, D>
 	where C::Target: chain::Notify,
 	      T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
+        D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	/// Creates a new object which can be used to monitor several channels given the chain
 	/// interface with which to register to receive notifications.
-	pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F) -> Self {
-		Self {
-			monitors: Mutex::new(HashMap::new()),
+	pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F, data_persister: D) -> Result<Self, ChannelMonitorUpdateErr> {
+		let monitors = match data_persister.load_channel_data() {
+			Ok(mons) => mons,
+			Err(e) => return Err(e)
+		};
+
+		Ok(Self {
+			monitors: Mutex::new(monitors),
 			chain_source,
 			broadcaster,
 			logger,
 			fee_estimator: feeest,
-		}
+			data_persister,
+		})
 	}
 
 	/// Adds or updates the monitor which monitors the channel referred to by the given outpoint.
@@ -275,6 +286,12 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 			hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given outpoint is already present")),
 			hash_map::Entry::Vacant(e) => e,
 		};
+		{
+			match self.data_persister.persist_channel_data(outpoint, &monitor) {
+				Err(_) => return Err(MonitorUpdateError("Unable to persist channel data")),
+				_ => {}
+			}
+		}
 		{
 			let funding_txo = monitor.get_funding_txo();
 			log_trace!(self.logger, "Got new Channel Monitor for channel {}", log_bytes!(funding_txo.0.to_channel_id()[..]));
@@ -295,21 +312,29 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 	/// Updates the monitor which monitors the channel referred to by the given outpoint.
 	pub fn update_monitor(&self, outpoint: OutPoint, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
 		let mut monitors = self.monitors.lock().unwrap();
-		match monitors.get_mut(&outpoint) {
-			Some(orig_monitor) => {
-				log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
-				orig_monitor.update_monitor(update, &self.broadcaster, &self.logger)
-			},
-			None => Err(MonitorUpdateError("No such monitor registered"))
+		if let Some(orig_monitor) = monitors.get_mut(&outpoint) {
+			log_trace!(self.logger, "Updating Channel Monitor for channel {}", log_funding_info!(orig_monitor));
+			if let Err(e) = orig_monitor.update_monitor(&update, &self.broadcaster, &self.logger) {
+				return Err(e)
+			}
+			match self.data_persister.update_channel_data(outpoint, &update, orig_monitor) {
+				Err(_) => return Err(MonitorUpdateError("Failed to persist monitor update")),
+				_ => {}
+			}
+		} else {
+			return Err(MonitorUpdateError("No such monitor registered"));
 		}
+
+		Ok(())
 	}
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, C, T, F, L>
+impl<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send, D: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, C, T, F, L, D>
 	where C::Target: chain::Notify,
 	      T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
+        D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	type Keys = ChanSigner;
 
@@ -336,11 +361,12 @@ impl<ChanSigner: ChannelKeys, C: Deref + Sync + Send, T: Deref + Sync + Send, F:
 	}
 }
 
-impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> events::EventsProvider for ChainMonitor<ChanSigner, C, T, F, L>
+impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, D: Deref> events::EventsProvider for ChainMonitor<ChanSigner, C, T, F, L, D>
 	where C::Target: chain::Notify,
 	      T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
+        D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	fn get_and_clear_pending_events(&self) -> Vec<Event> {
 		let mut pending_events = Vec::new();
@@ -1339,30 +1365,29 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
 	/// itself.
 	///
 	/// panics if the given update is not the next update by update_id.
-	pub fn update_monitor<B: Deref, L: Deref>(&mut self, mut updates: ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
+	pub fn update_monitor<B: Deref, L: Deref>(&mut self, updates: &ChannelMonitorUpdate, broadcaster: &B, logger: &L) -> Result<(), MonitorUpdateError>
 		where B::Target: BroadcasterInterface,
 					L::Target: Logger,
 	{
 		if self.latest_update_id + 1 != updates.update_id {
 			panic!("Attempted to apply ChannelMonitorUpdates out of order, check the update_id before passing an update to update_monitor!");
 		}
-		for update in updates.updates.drain(..) {
+		for update in updates.updates.iter() {
 			match update {
 				ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { commitment_tx, htlc_outputs } => {
 					if self.lockdown_from_offchain { panic!(); }
-					self.provide_latest_local_commitment_tx_info(commitment_tx, htlc_outputs)?
+					self.provide_latest_local_commitment_tx_info(commitment_tx.clone(), htlc_outputs.clone())?
 				},
 				ChannelMonitorUpdateStep::LatestRemoteCommitmentTXInfo { unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point } =>
-					self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs, commitment_number, their_revocation_point, logger),
+					self.provide_latest_remote_commitment_tx_info(&unsigned_commitment_tx, htlc_outputs.clone(), *commitment_number, *their_revocation_point, logger),
 				ChannelMonitorUpdateStep::PaymentPreimage { payment_preimage } =>
 					self.provide_payment_preimage(&PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()), &payment_preimage),
 				ChannelMonitorUpdateStep::CommitmentSecret { idx, secret } =>
-					self.provide_secret(idx, secret)?,
+					self.provide_secret(*idx, *secret)?,
 				ChannelMonitorUpdateStep::ChannelForceClosed { should_broadcast } => {
 					self.lockdown_from_offchain = true;
-					if should_broadcast {
-						self.broadcast_latest_local_commitment_txn(broadcaster, logger);
-					} else {
+					if *should_broadcast {
+						self.broadcast_latest_local_commitment_txn(broadcaster, logger);} else {
 						log_error!(logger, "You have a toxic local commitment transaction avaible in channel monitor, read comment in ChannelMonitor::get_latest_local_commitment_txn to be informed of manual action to take");
 					}
 				}