Merge pull request #49 from getAlby/feat/get-encoded-channel-monitors

feat: get encoded channel monitors

bindings/ldk_node.udl

@@ -43,6 +43,7 @@ interface Builder {
 	Node build();
 	[Throws=BuildError]
 	Node build_with_fs_store();
+	void restore_encoded_channel_monitors(sequence<KeyValue> monitors);
 };
 
 interface Node {
@@ -90,6 +91,9 @@ interface Node {
 	[Throws=NodeError]
 	string sign_message([ByRef]sequence<u8> msg);
 	boolean verify_signature([ByRef]sequence<u8> msg, [ByRef]string sig, [ByRef]PublicKey pkey);
+	[Throws=NodeError]
+	sequence<KeyValue> get_encoded_channel_monitors();
+	void force_close_all_channels_without_broadcasting_txn();
 };
 
 interface Bolt11Payment {
@@ -424,6 +428,11 @@ dictionary TlvEntry {
 	sequence<u8> value;
 };
 
+dictionary KeyValue {
+	string key;
+	sequence<u8> value;
+};
+
 interface NetworkGraph {
 	sequence<u64> list_channels();
 	ChannelInfo? channel(u64 short_channel_id);

src/builder.rs

@@ -15,8 +15,8 @@ use crate::payment::store::PaymentStore;
 use crate::peer_store::PeerStore;
 use crate::tx_broadcaster::TransactionBroadcaster;
 use crate::types::{
-	ChainMonitor, ChannelManager, DynStore, GossipSync, Graph, KeysManager, MessageRouter,
-	OnionMessenger, PeerManager,
+	ChainMonitor, ChannelManager, DynStore, GossipSync, Graph, KeyValue, KeysManager,
+	MessageRouter, OnionMessenger, PeerManager,
 };
 use crate::wallet::Wallet;
 use crate::{LogLevel, Node};
@@ -172,6 +172,7 @@ pub struct NodeBuilder {
 	chain_data_source_config: Option<ChainDataSourceConfig>,
 	gossip_source_config: Option<GossipSourceConfig>,
 	liquidity_source_config: Option<LiquiditySourceConfig>,
+	monitors_to_restore: Option<Vec<KeyValue>>,
 }
 
 impl NodeBuilder {
@@ -187,15 +188,23 @@ impl NodeBuilder {
 		let chain_data_source_config = None;
 		let gossip_source_config = None;
 		let liquidity_source_config = None;
+		let monitors_to_restore = None;
 		Self {
 			config,
 			entropy_source_config,
 			chain_data_source_config,
 			gossip_source_config,
 			liquidity_source_config,
+			monitors_to_restore,
 		}
 	}
 
+	/// Alby: set monitors to restore when restoring SCB
+	pub fn restore_encoded_channel_monitors(&mut self, monitors: Vec<KeyValue>) -> &mut Self {
+		self.monitors_to_restore = Some(monitors);
+		self
+	}
+
 	/// Configures the [`Node`] instance to source its wallet entropy from a seed file on disk.
 	///
 	/// If the given file does not exist a new random seed file will be generated and
@@ -316,6 +325,7 @@ impl NodeBuilder {
 			)
 			.map_err(|_| BuildError::KVStoreSetupFailed)?,
 		);
+
 		self.build_with_store(kv_store)
 	}
 
@@ -381,6 +391,17 @@ impl NodeBuilder {
 		)?;
 		let config = Arc::new(self.config.clone());
 
+		// Alby: Restore encoded channel monitors for a recovery of last resort
+		if self.monitors_to_restore.is_some() {
+			let monitors = self.monitors_to_restore.clone().unwrap();
+			for monitor in monitors {
+				let result = kv_store.write("monitors", "", &monitor.key, &monitor.value);
+				if result.is_err() {
+					log_error!(logger, "Failed to restore monitor: {}", result.unwrap_err());
+				}
+			}
+		}
+
 		build_with_store_internal(
 			config,
 			self.chain_data_source_config.as_ref(),
@@ -420,6 +441,11 @@ impl ArcedNodeBuilder {
 		Self { inner }
 	}
 
+	/// Alby: set monitors to restore when restoring SCB
+	pub fn restore_encoded_channel_monitors(&self, monitors: Vec<KeyValue>) {
+		self.inner.write().unwrap().restore_encoded_channel_monitors(monitors);
+	}
+
 	/// Configures the [`Node`] instance to source its wallet entropy from a seed file on disk.
 	///
 	/// If the given file does not exist a new random seed file will be generated and

src/lib.rs

@@ -140,7 +140,7 @@ use types::{
 	Broadcaster, BumpTransactionEventHandler, ChainMonitor, ChannelManager, DynStore, FeeEstimator,
 	Graph, KeysManager, PeerManager, Router, Scorer, Sweeper, Wallet,
 };
-pub use types::{ChannelDetails, ChannelType, PeerDetails, TlvEntry, UserChannelId};
+pub use types::{ChannelDetails, ChannelType, KeyValue, PeerDetails, TlvEntry, UserChannelId};
 
 use logger::{log_error, log_info, log_trace, FilesystemLogger, Logger};
 
@@ -1539,6 +1539,33 @@ impl Node {
 		self.payment_store.remove(&payment_id)
 	}
 
+	/// Alby: Used to recover funds after restoring static channel backup
+	pub fn force_close_all_channels_without_broadcasting_txn(&self) {
+		self.channel_manager.force_close_all_channels_without_broadcasting_txn();
+	}
+
+	/// Alby: Return encoded channel monitors for a recovery of last resort
+	pub fn get_encoded_channel_monitors(&self) -> Result<Vec<KeyValue>, Error> {
+		let channel_monitor_store = Arc::clone(&self.kv_store);
+		let channel_monitor_logger = Arc::clone(&self.logger);
+		let keys = channel_monitor_store.list("monitors", "").map_err(|e| {
+			log_error!(channel_monitor_logger, "Failed to get monitor keys: {}", e);
+			Error::ConnectionFailed
+		})?;
+
+		let mut entries = Vec::new();
+
+		for key in keys {
+			let value = channel_monitor_store.read("monitors", "", &key).map_err(|e| {
+				log_error!(channel_monitor_logger, "Failed to get monitor value: {}", e);
+				Error::ConnectionFailed
+			})?;
+			entries.push(KeyValue { key, value })
+		}
+
+		return Ok(entries);
+	}
+
 	/// Retrieves an overview of all known balances.
 	pub fn list_balances(&self) -> BalanceDetails {
 		let cur_anchor_reserve_sats =

src/types.rs

@@ -492,3 +492,12 @@ impl_writeable_tlv_based!(TlvEntry, {
 	(0, r#type, required),
 	(1, value, required),
 });
+
+/// KeyValue from LDK node DB
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct KeyValue {
+	/// Key.
+	pub key: String,
+	/// Serialized value.
+	pub value: Vec<u8>,
+}