Handle ConnectionNeeded events

We spawn a background task that will try to connect to any of the
provided socket addresses and return as soon as it suceeds.

src/event.rs

@@ -1,8 +1,11 @@
-use crate::types::{DynStore, Sweeper, Wallet};
+use crate::types::{DynStore, PeerManager, Sweeper, Wallet};
+
 use crate::{
 	hex_utils, ChannelManager, Config, Error, NetworkGraph, PeerInfo, PeerStore, UserChannelId,
 };
 
+use crate::connection::connect_peer_if_necessary;
+
 use crate::payment_store::{
 	PaymentDetails, PaymentDetailsUpdate, PaymentDirection, PaymentStatus, PaymentStore,
 };
@@ -287,6 +290,7 @@ where
 	event_queue: Arc<EventQueue<L>>,
 	wallet: Arc<Wallet>,
 	channel_manager: Arc<ChannelManager>,
+	peer_manager: Arc<PeerManager>,
 	output_sweeper: Arc<Sweeper>,
 	network_graph: Arc<NetworkGraph>,
 	payment_store: Arc<PaymentStore<L>>,
@@ -302,14 +306,16 @@ where
 {
 	pub fn new(
 		event_queue: Arc<EventQueue<L>>, wallet: Arc<Wallet>, channel_manager: Arc<ChannelManager>,
-		output_sweeper: Arc<Sweeper>, network_graph: Arc<NetworkGraph>,
-		payment_store: Arc<PaymentStore<L>>, peer_store: Arc<PeerStore<L>>,
-		runtime: Arc<RwLock<Option<tokio::runtime::Runtime>>>, logger: L, config: Arc<Config>,
+		peer_manager: Arc<PeerManager>, output_sweeper: Arc<Sweeper>,
+		network_graph: Arc<NetworkGraph>, payment_store: Arc<PaymentStore<L>>,
+		peer_store: Arc<PeerStore<L>>, runtime: Arc<RwLock<Option<tokio::runtime::Runtime>>>,
+		logger: L, config: Arc<Config>,
 	) -> Self {
 		Self {
 			event_queue,
 			wallet,
 			channel_manager,
+			peer_manager,
 			output_sweeper,
 			network_graph,
 			payment_store,
@@ -862,7 +868,41 @@ where
 			LdkEvent::HTLCIntercepted { .. } => {}
 			LdkEvent::BumpTransaction(_) => {}
 			LdkEvent::InvoiceRequestFailed { .. } => {}
-			LdkEvent::ConnectionNeeded { .. } => {}
+			LdkEvent::ConnectionNeeded { node_id, addresses } => {
+				let runtime_lock = self.runtime.read().unwrap();
+				debug_assert!(runtime_lock.is_some());
+
+				if let Some(runtime) = runtime_lock.as_ref() {
+					let spawn_logger = self.logger.clone();
+					let spawn_pm = Arc::clone(&self.peer_manager);
+					let addresses = addresses.clone();
+					runtime.spawn(async move {
+						for addr in &addresses {
+							match connect_peer_if_necessary(
+								node_id,
+								addr.clone(),
+								Arc::clone(&spawn_pm),
+								spawn_logger.clone(),
+							)
+							.await
+							{
+								Ok(()) => {
+									return;
+								}
+								Err(e) => {
+									log_error!(
+										spawn_logger,
+										"Failed to establish connection to peer {}@{}: {}",
+										node_id,
+										addr,
+										e
+									);
+								}
+							}
+						}
+					});
+				}
+			}
 		}
 	}
 }

src/lib.rs

@@ -713,6 +713,7 @@ impl Node {
 			Arc::clone(&self.event_queue),
 			Arc::clone(&self.wallet),
 			Arc::clone(&self.channel_manager),
+			Arc::clone(&self.peer_manager),
 			Arc::clone(&self.output_sweeper),
 			Arc::clone(&self.network_graph),
 			Arc::clone(&self.payment_store),