Expose APIs to access node's supported feature flags

src/event.rs

@@ -49,8 +49,9 @@ use crate::payment::store::{
 	PaymentDetails, PaymentDetailsUpdate, PaymentDirection, PaymentKind, PaymentStatus,
 };
 use crate::runtime::Runtime;
-use crate::types::KeysManager;
-use crate::types::{CustomTlvRecord, DynStore, OnionMessenger, PaymentStore, Sweeper, Wallet};
+use crate::types::{
+	CustomTlvRecord, DynStore, KeysManager, OnionMessenger, PaymentStore, Sweeper, Wallet,
+};
 use crate::{
 	hex_utils, BumpTransactionEventHandler, ChannelManager, Error, Graph, PeerInfo, PeerStore,
 	UserChannelId,

src/lib.rs

@@ -141,12 +141,16 @@ use lightning::chain::BestBlock;
 use lightning::impl_writeable_tlv_based;
 use lightning::ln::channel_state::{ChannelDetails as LdkChannelDetails, ChannelShutdownState};
 use lightning::ln::channelmanager::PaymentId;
-use lightning::ln::msgs::SocketAddress;
+use lightning::ln::msgs::{BaseMessageHandler, SocketAddress};
+use lightning::ln::peer_handler::CustomMessageHandler;
 use lightning::routing::gossip::NodeAlias;
 use lightning::sign::EntropySource;
 use lightning::util::persist::KVStoreSync;
 use lightning::util::wallet_utils::Wallet as LdkWallet;
 use lightning_background_processor::process_events_async;
+use lightning_types::features::{
+	Bolt11InvoiceFeatures, ChannelFeatures, InitFeatures, NodeFeatures,
+};
 use liquidity::{LSPS1Liquidity, LiquiditySource};
 use logger::{log_debug, log_error, log_info, log_trace, LdkLogger, Logger};
 use payment::asynchronous::om_mailbox::OnionMessageMailbox;
@@ -1725,6 +1729,63 @@ impl Node {
 			Error::PersistenceFailed
 		})
 	}
+
+	/// Return the features used in node announcement.
+	pub fn node_features(&self) -> NodeFeatures {
+		let gossip_features = match self.gossip_source.as_gossip_sync() {
+			lightning_background_processor::GossipSync::P2P(p2p_gossip_sync) => {
+				p2p_gossip_sync.provided_node_features()
+			},
+			lightning_background_processor::GossipSync::Rapid(_) => NodeFeatures::empty(),
+			lightning_background_processor::GossipSync::None => {
+				unreachable!("We must always have a gossip sync!")
+			},
+		};
+		self.channel_manager.node_features()
+			| self.chain_monitor.provided_node_features()
+			| self.onion_messenger.provided_node_features()
+			| gossip_features
+			| self
+				.liquidity_source
+				.as_ref()
+				.map(|ls| ls.liquidity_manager().provided_node_features())
+				.unwrap_or_else(NodeFeatures::empty)
+	}
+
+	/// Return the node's init features.
+	pub fn init_features(&self) -> InitFeatures {
+		let gossip_init_features = match self.gossip_source.as_gossip_sync() {
+			lightning_background_processor::GossipSync::P2P(p2p_gossip_sync) => {
+				p2p_gossip_sync.provided_init_features(self.node_id())
+			},
+			lightning_background_processor::GossipSync::Rapid(_) => InitFeatures::empty(),
+			lightning_background_processor::GossipSync::None => {
+				unreachable!("We must always have a gossip sync!")
+			},
+		};
+		self.channel_manager.init_features()
+			| self.chain_monitor.provided_init_features(self.node_id())
+			| self.onion_messenger.provided_init_features(self.node_id())
+			| gossip_init_features
+			| self
+				.liquidity_source
+				.as_ref()
+				.map(|ls| ls.liquidity_manager().provided_init_features(self.node_id()))
+				.unwrap_or_else(InitFeatures::empty)
+	}
+
+	/// Return the node's channel features.
+	pub fn channel_features(&self) -> ChannelFeatures {
+		self.channel_manager.channel_features()
+	}
+
+	/// Return the node's BOLT 11 invoice features.
+	pub fn bolt11_invoice_features(&self) -> Bolt11InvoiceFeatures {
+		// bolt11_invoice_features() is not public because feature
+		// flags can vary due to invoice type, so we convert from
+		// context.
+		self.channel_manager.init_features().to_context()
+	}
 }
 
 impl Drop for Node {

tests/integration_tests_rust.rs

@@ -2627,3 +2627,37 @@ async fn onchain_fee_bump_rbf() {
 	assert_eq!(node_a_received_payment[0].amount_msat, Some(amount_to_send_sats * 1000));
 	assert_eq!(node_a_received_payment[0].status, PaymentStatus::Succeeded);
 }
+
+#[test]
+fn node_feature_flags() {
+	let (bitcoind, electrsd) = setup_bitcoind_and_electrsd();
+	let chain_source = random_chain_source(&bitcoind, &electrsd);
+	let config = random_config(true);
+	let node = setup_node(&chain_source, config);
+
+	// NodeFeatures
+	let node_features = node.node_features();
+	assert!(node_features.supports_variable_length_onion());
+	assert!(node_features.supports_payment_secret());
+	assert!(node_features.supports_basic_mpp());
+	assert!(node_features.supports_keysend());
+	assert!(node_features.supports_onion_messages());
+
+	// InitFeatures
+	let init_features = node.init_features();
+	assert!(init_features.supports_variable_length_onion());
+	assert!(init_features.supports_payment_secret());
+	assert!(init_features.supports_basic_mpp());
+	assert!(init_features.supports_onion_messages());
+
+	// ChannelFeatures (non-empty)
+	let _channel_features = node.channel_features();
+
+	// Bolt11InvoiceFeatures
+	let bolt11_features = node.bolt11_invoice_features();
+	assert!(bolt11_features.supports_variable_length_onion());
+	assert!(bolt11_features.supports_payment_secret());
+	assert!(bolt11_features.supports_basic_mpp());
+
+	node.stop().unwrap();
+}