Integrate ChannelDataPersister into ChainMonitor.

- add a test for the LinuxPersister.
- update MonitorUpdateErr to have a boolean whether the updated
  ChannelMonitor should be persisted despite the error
- The ChainMonitor should:
  1) Call the ChannelDataPersister on startup to retrieve the stored
     monitors from disk,
  2) Whenever a new channel is added or updated, these updates
     should be conveyed to the DataPersister and persisted to disk.

Author: valentinewallace

fuzz/src/chanmon_consistency.rs

@@ -36,6 +36,7 @@ use lightning::chain::transaction::OutPoint;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::keysinterface::{KeysInterface, InMemoryChannelKeys};
 use lightning::ln::channelmanager::{ChannelManager, PaymentHash, PaymentPreimage, PaymentSecret, ChannelManagerReadArgs};
+use lightning::ln::data_persister::ChannelDataPersister;
 use lightning::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
 use lightning::ln::msgs::{CommitmentUpdate, ChannelMessageHandler, ErrorAction, UpdateAddHTLC, Init};
 use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
@@ -47,6 +48,7 @@ use lightning::util::ser::{Readable, ReadableArgs, Writeable, Writer};
 use lightning::routing::router::{Route, RouteHop};
 
 
+use utils::test_data_persister::TestChanDataPersister;
 use utils::test_logger;
 
 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
@@ -84,7 +86,7 @@ impl Writer for VecWriter {
 
 struct TestChainMonitor {
 	pub logger: Arc<dyn Logger>,
-	pub chain_monitor: Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	pub chain_monitor: Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, 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(chainmonitor::ChainMonitor::new(None, broadcaster, logger.clone(), feeest)),
+			chain_monitor: Arc::new(chainmonitor::ChainMonitor::new(None, broadcaster, logger.clone(), feeest, data_persister)),
 			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::chainmonitor;
 use lightning::chain::transaction::OutPoint;
 use lightning::chain::keysinterface::{InMemoryChannelKeys, KeysInterface};
 use lightning::ln::channelmanager::{ChannelManager, PaymentHash, PaymentPreimage, PaymentSecret};
+use lightning::ln::data_persister::ChannelDataPersister;
 use lightning::ln::peer_handler::{MessageHandler,PeerManager,SocketDescriptor};
 use lightning::routing::router::get_route;
 use lightning::routing::network_graph::NetGraphMsgHandler;
@@ -39,6 +40,7 @@ use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
 use lightning::util::logger::Logger;
 use lightning::util::config::UserConfig;
 
+use utils::test_data_persister::TestChanDataPersister;
 use utils::test_logger;
 
 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
@@ -145,13 +147,13 @@ impl<'a> std::hash::Hash for Peer<'a> {
 
 type ChannelMan = ChannelManager<
 	EnforcingChannelKeys,
-	Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, 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<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	monitor: Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	handler: PeerMan<'a>,
 
 	peers: &'a RefCell<[bool; 256]>,
@@ -165,7 +167,7 @@ struct MoneyLossDetector<'a> {
 impl<'a> MoneyLossDetector<'a> {
 	pub fn new(peers: &'a RefCell<[bool; 256]>,
 	           manager: Arc<ChannelMan>,
-	           monitor: Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	           monitor: Arc<chainmonitor::ChainMonitor<EnforcingChannelKeys, Arc<dyn chain::Filter>, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>, Arc<dyn ChannelDataPersister<Keys=EnforcingChannelKeys>>>>,
 	           handler: PeerMan<'a>) -> Self {
 		MoneyLossDetector {
 			manager,
@@ -333,7 +335,8 @@ pub fn do_test(data: &[u8], logger: &Arc<dyn Logger>) {
 	};
 
 	let broadcast = Arc::new(TestBroadcaster{});
-	let monitor = Arc::new(chainmonitor::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(chainmonitor::ChainMonitor::new(None, broadcast.clone(), Arc::clone(&logger), fee_est.clone(), data_persister.clone()));
 
 	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

@@ -7,4 +7,5 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
+pub mod test_data_persister;
 pub mod test_logger;

fuzz/src/utils/test_data_persister.rs

@@ -0,0 +1,17 @@
+use lightning::ln::data_persister::ChannelDataPersister;
+use lightning::chain::channelmonitor;
+use lightning::chain::transaction::OutPoint;
+use lightning::util::enforcing_trait_impls::EnforcingChannelKeys;
+
+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(())
+	}
+}

lightning-net-tokio/src/lib.rs

@@ -36,7 +36,8 @@
 //! type Logger = dyn lightning::util::logger::Logger;
 //! type ChainAccess = dyn lightning::chain::Access;
 //! type ChainFilter = dyn lightning::chain::Filter;
-//! type ChainMonitor = lightning::chain::chainmonitor::ChainMonitor<lightning::chain::keysinterface::InMemoryChannelKeys, Arc<ChainFilter>, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>>;
+//! type DataPersister = dyn lightning::ln::data_persister::ChannelDataPersister<Keys = lightning::chain::keysinterface::InMemoryChannelKeys>;
+//! type ChainMonitor = lightning::chain::chainmonitor::ChainMonitor<lightning::chain::keysinterface::InMemoryChannelKeys, Arc<ChainFilter>, 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/chainmonitor.rs

@@ -37,6 +37,7 @@ use chain::chaininterface::{BroadcasterInterface, FeeEstimator};
 use chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, MonitorEvent, MonitorUpdateError};
 use chain::transaction::{OutPoint, TransactionData};
 use chain::keysinterface::ChannelKeys;
+use ln::data_persister::ChannelDataPersister;
 use util::logger::Logger;
 use util::events;
 use util::events::Event;
@@ -55,25 +56,28 @@ use std::ops::Deref;
 /// [`chain::Watch`]: ../trait.Watch.html
 /// [`ChannelManager`]: ../../ln/channelmanager/struct.ChannelManager.html
 /// [module-level documentation]: index.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::Filter,
         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>
-	where C::Target: chain::Filter,
-	      T::Target: BroadcasterInterface,
-	      F::Target: FeeEstimator,
-	      L::Target: Logger,
+impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref, D: Deref> ChainMonitor<ChanSigner, C, T, F, L, D>
+where C::Target: chain::Filter,
+	    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
@@ -128,13 +132,14 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 	/// transactions relevant to the watched channels.
 	///
 	/// [`chain::Filter`]: ../trait.Filter.html
-	pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F) -> Self {
+	pub fn new(chain_source: Option<C>, broadcaster: T, logger: L, feeest: F, data_persister: D) -> Self {
 		Self {
 			monitors: Mutex::new(HashMap::new()),
 			chain_source,
 			broadcaster,
 			logger,
 			fee_estimator: feeest,
+			data_persister,
 		}
 	}
 
@@ -143,10 +148,12 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 	/// Calls back to [`chain::Filter`] with the funding transaction and outputs to watch.
 	///
 	/// [`chain::Filter`]: ../trait.Filter.html
-	fn add_monitor(&self, outpoint: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
+	fn add_monitor(&self, outpoint: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
 		let mut monitors = self.monitors.lock().unwrap();
 		let entry = match monitors.entry(outpoint) {
-			hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given outpoint is already present")),
+			hash_map::Entry::Occupied(_) => {
+				log_error!(self.logger, "Failed to add new channel data: channel monitor for given outpoint is already present");
+				return Err(ChannelMonitorUpdateErr::PermanentFailure)},
 			hash_map::Entry::Vacant(e) => e,
 		};
 		{
@@ -162,43 +169,69 @@ impl<ChanSigner: ChannelKeys, C: Deref, T: Deref, F: Deref, L: Deref> ChainMonit
 				}
 			}
 		}
+		match self.data_persister.persist_channel_data(outpoint, &monitor) {
+			Err(e) => {
+				log_error!(self.logger, "Failed to persist new channel data");
+				return Err(e);
+			},
+			_ => {}
+		}
 		entry.insert(monitor);
 		Ok(())
 	}
 
 	/// Updates the monitor that watches the channel referred to by the given outpoint.
-	fn update_monitor(&self, outpoint: OutPoint, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
+	fn update_monitor(&self, outpoint: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
 		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));
+      let mut should_persist = true;
+      let res = orig_monitor.update_monitor(&update, &self.broadcaster, &self.logger);
+      match res {
+        Err(MonitorUpdateError::PersistMonitor(msg)) => {
+          log_error!(self.logger, "{}", msg);
+        },
+        Err(MonitorUpdateError::NoPersistMonitor(msg)) => {
+          log_error!(self.logger, "{}", msg);
+          should_persist = false;
+        },
+        Ok(()) => {},
+      }
+      if should_persist {
+        match self.data_persister.update_channel_data(outpoint, &update, orig_monitor) {
+          Err(e) => {
+            if !res.is_err() {
+              return Err(e);
+            }
+          },
+          _ => {}
+        }
+      }
+      if res.is_err() { return Err(ChannelMonitorUpdateErr::PermanentFailure); }
+    } else {
+      log_error!(self.logger, "Failed to update channel monitor: no such monitor registered");
+      return Err(ChannelMonitorUpdateErr::PermanentFailure);
+    }
+
+    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>
-	where C::Target: chain::Filter,
-	      T::Target: BroadcasterInterface,
-	      F::Target: FeeEstimator,
-	      L::Target: Logger,
+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::Filter,
+	    T::Target: BroadcasterInterface,
+	    F::Target: FeeEstimator,
+	    L::Target: Logger,
+	    D::Target: ChannelDataPersister<Keys=ChanSigner>,
 {
 	type Keys = ChanSigner;
 
 	fn watch_channel(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
-		match self.add_monitor(funding_txo, monitor) {
-			Ok(_) => Ok(()),
-			Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
-		}
+		self.add_monitor(funding_txo, monitor)
 	}
 
 	fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
-		match self.update_monitor(funding_txo, update) {
-			Ok(_) => Ok(()),
-			Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
-		}
+		self.update_monitor(funding_txo, update)
 	}
 
 	fn release_pending_monitor_events(&self) -> Vec<MonitorEvent> {
@@ -210,11 +243,12 @@ 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::Filter,
 	      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();