Remove Key parameter from ChainMonitor

jkczyz · jkczyz · commit addc49d7999d · 2020-08-06T16:54:13.000-07:00
ChainMonitor's template Key parameter was meant to allow supporting
both local monitoring, where Key=OutPoint, and watchtowers, where Key=
(PublicKey, u32). Use OutPoint directly since the watchtower case will
not be supported this way.
diff --git a/fuzz/src/chanmon_consistency.rs b/fuzz/src/chanmon_consistency.rs
@@ -75,7 +75,7 @@ impl Writer for VecWriter {
 
 struct TestChainMonitor {
 	pub logger: Arc<dyn Logger>,
-	pub chain_monitor: Arc<channelmonitor::ChainMonitor<OutPoint, EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	pub chain_monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
 	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
diff --git a/fuzz/src/full_stack.rs b/fuzz/src/full_stack.rs
@@ -137,14 +137,13 @@ impl<'a> std::hash::Hash for Peer<'a> {
 
 type ChannelMan = ChannelManager<
 	EnforcingChannelKeys,
-	Arc<channelmonitor::ChainMonitor<OutPoint, EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
 	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<
-		OutPoint, EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
 	handler: PeerMan<'a>,
 
 	peers: &'a RefCell<[bool; 256]>,
@@ -158,7 +157,7 @@ struct MoneyLossDetector<'a> {
 impl<'a> MoneyLossDetector<'a> {
 	pub fn new(peers: &'a RefCell<[bool; 256]>,
 	           manager: Arc<ChannelMan>,
-	           monitor: Arc<channelmonitor::ChainMonitor<OutPoint, EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
+	           monitor: Arc<channelmonitor::ChainMonitor<EnforcingChannelKeys, Arc<TestBroadcaster>, Arc<FuzzEstimator>, Arc<dyn Logger>>>,
 	           handler: PeerMan<'a>) -> Self {
 		MoneyLossDetector {
 			manager,
diff --git a/lightning-net-tokio/src/lib.rs b/lightning-net-tokio/src/lib.rs
@@ -26,7 +26,7 @@
 //! type FeeEstimator = dyn lightning::chain::chaininterface::FeeEstimator;
 //! type Logger = dyn lightning::util::logger::Logger;
 //! type ChainAccess = dyn lightning::chain::Access;
-//! type ChainMonitor = lightning::ln::channelmonitor::ChainMonitor<lightning::chain::transaction::OutPoint, lightning::chain::keysinterface::InMemoryChannelKeys, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>>;
+//! type ChainMonitor = lightning::ln::channelmonitor::ChainMonitor<lightning::chain::keysinterface::InMemoryChannelKeys, Arc<TxBroadcaster>, Arc<FeeEstimator>, Arc<Logger>>;
 //! 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>;
 //!
diff --git a/lightning/src/ln/channelmonitor.rs b/lightning/src/ln/channelmonitor.rs
@@ -44,7 +44,7 @@ use util::{byte_utils, events};
 
 use std::collections::{HashMap, hash_map};
 use std::sync::Mutex;
-use std::{hash,cmp, mem};
+use std::{cmp, mem};
 use std::ops::Deref;
 
 /// An update generated by the underlying Channel itself which contains some new information the
@@ -154,28 +154,22 @@ pub struct HTLCUpdate {
 }
 impl_writeable!(HTLCUpdate, 0, { payment_hash, payment_preimage, source });
 
-/// A simple implementation of a [`chain::Watch`] and ChainListener. Can be used to create a
-/// watchtower or watch our own channels.
+/// An implementation of a [`chain::Watch`] and ChainListener.
 ///
-/// Note that you must provide your own key by which to refer to channels.
-///
-/// If you're accepting remote monitors (ie are implementing a watchtower), you must verify that
-/// users cannot overwrite a given channel by providing a duplicate key. ie you should probably
-/// index by a PublicKey which is required to sign any updates.
-///
-/// 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 [`chain::Watch`] implementation.
+/// May be used in conjunction with [`ChannelManager`] to monitor channels locally or used
+/// independently to monitor channels remotely.
 ///
 /// [`chain::Watch`]: ../../chain/trait.Watch.html
-pub struct ChainMonitor<Key, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref>
+/// [`ChannelManager`]: ../channelmanager/struct.ChannelManager.html
+pub struct ChainMonitor<ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref>
 	where T::Target: BroadcasterInterface,
         F::Target: FeeEstimator,
         L::Target: Logger,
 {
 	#[cfg(test)] // Used in ChannelManager tests to manipulate channels directly
-	pub monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
+	pub monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
 	#[cfg(not(test))]
-	monitors: Mutex<HashMap<Key, ChannelMonitor<ChanSigner>>>,
+	monitors: Mutex<HashMap<OutPoint, ChannelMonitor<ChanSigner>>>,
 	watch_events: Mutex<WatchEventQueue>,
 	broadcaster: T,
 	logger: L,
@@ -224,8 +218,8 @@ impl WatchEventQueue {
 	}
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send>
-	ChainListener for ChainMonitor<Key, ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send>
+	ChainListener for ChainMonitor<ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
@@ -255,14 +249,14 @@ impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref + Sync
 	}
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> ChainMonitor<Key, ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> ChainMonitor<ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
 {
 	/// 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(broadcaster: T, logger: L, feeest: F) -> ChainMonitor<Key, ChanSigner, T, F, L> {
+	pub fn new(broadcaster: T, logger: L, feeest: F) -> Self {
 		Self {
 			monitors: Mutex::new(HashMap::new()),
 			watch_events: Mutex::new(WatchEventQueue::new()),
@@ -272,12 +266,12 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
 		}
 	}
 
-	/// Adds or updates the monitor which monitors the channel referred to by the given key.
-	pub fn add_monitor_by_key(&self, key: Key, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
+	/// Adds or updates the monitor which monitors the channel referred to by the given outpoint.
+	pub fn add_monitor(&self, outpoint: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), MonitorUpdateError> {
 		let mut watch_events = self.watch_events.lock().unwrap();
 		let mut monitors = self.monitors.lock().unwrap();
-		let entry = match monitors.entry(key) {
-			hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given key is already present")),
+		let entry = match monitors.entry(outpoint) {
+			hash_map::Entry::Occupied(_) => return Err(MonitorUpdateError("Channel monitor for given outpoint is already present")),
 			hash_map::Entry::Vacant(e) => e,
 		};
 		{
@@ -295,10 +289,10 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
 		Ok(())
 	}
 
-	/// Updates the monitor which monitors the channel referred to by the given key.
-	pub fn update_monitor_by_key(&self, key: Key, update: ChannelMonitorUpdate) -> Result<(), MonitorUpdateError> {
+	/// 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(&key) {
+		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)
@@ -308,22 +302,22 @@ impl<Key : Send + cmp::Eq + hash::Hash + 'static, ChanSigner: ChannelKeys, T: De
 	}
 }
 
-impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> chain::Watch for ChainMonitor<OutPoint, ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L: Deref + Sync + Send> chain::Watch for ChainMonitor<ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
 {
 	type Keys = ChanSigner;
 
 	fn watch_channel(&self, funding_txo: OutPoint, monitor: ChannelMonitor<ChanSigner>) -> Result<(), ChannelMonitorUpdateErr> {
-		match self.add_monitor_by_key(funding_txo, monitor) {
+		match self.add_monitor(funding_txo, monitor) {
 			Ok(_) => Ok(()),
 			Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 		}
 	}
 
 	fn update_channel(&self, funding_txo: OutPoint, update: ChannelMonitorUpdate) -> Result<(), ChannelMonitorUpdateErr> {
-		match self.update_monitor_by_key(funding_txo, update) {
+		match self.update_monitor(funding_txo, update) {
 			Ok(_) => Ok(()),
 			Err(_) => Err(ChannelMonitorUpdateErr::PermanentFailure),
 		}
@@ -338,7 +332,7 @@ impl<ChanSigner: ChannelKeys, T: Deref + Sync + Send, F: Deref + Sync + Send, L:
 	}
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> events::EventsProvider for ChainMonitor<Key, ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> events::EventsProvider for ChainMonitor<ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
@@ -352,7 +346,7 @@ impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: De
 	}
 }
 
-impl<Key : Send + cmp::Eq + hash::Hash, ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> chain::WatchEventProvider for ChainMonitor<Key, ChanSigner, T, F, L>
+impl<ChanSigner: ChannelKeys, T: Deref, F: Deref, L: Deref> chain::WatchEventProvider for ChainMonitor<ChanSigner, T, F, L>
 	where T::Target: BroadcasterInterface,
 	      F::Target: FeeEstimator,
 	      L::Target: Logger,
diff --git a/lightning/src/util/test_utils.rs b/lightning/src/util/test_utils.rs
@@ -54,7 +54,7 @@ impl chaininterface::FeeEstimator for TestFeeEstimator {
 pub struct TestChainMonitor<'a> {
 	pub added_monitors: Mutex<Vec<(OutPoint, channelmonitor::ChannelMonitor<EnforcingChannelKeys>)>>,
 	pub latest_monitor_update_id: Mutex<HashMap<[u8; 32], (OutPoint, u64)>>,
-	pub chain_monitor: channelmonitor::ChainMonitor<OutPoint, EnforcingChannelKeys, &'a chaininterface::BroadcasterInterface, &'a TestFeeEstimator, &'a TestLogger>,
+	pub chain_monitor: channelmonitor::ChainMonitor<EnforcingChannelKeys, &'a chaininterface::BroadcasterInterface, &'a TestFeeEstimator, &'a TestLogger>,
 	pub update_ret: Mutex<Result<(), channelmonitor::ChannelMonitorUpdateErr>>,
 	// If this is set to Some(), after the next return, we'll always return this until update_ret
 	// is changed:
