Support custom onion messages

lightning/src/ln/peer_handler.rs

@@ -21,11 +21,11 @@ use ln::features::{InitFeatures, NodeFeatures};
 use ln::msgs;
 use ln::msgs::{ChannelMessageHandler, LightningError, NetAddress, OnionMessageHandler, RoutingMessageHandler};
 use ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager};
-use util::ser::{VecWriter, Writeable, Writer};
+use util::ser::{MaybeReadableArgs, VecWriter, Writeable, Writer};
 use ln::peer_channel_encryptor::{PeerChannelEncryptor,NextNoiseStep};
 use ln::wire;
 use ln::wire::Encode;
-use onion_message::{SimpleArcOnionMessenger, SimpleRefOnionMessenger};
+use onion_message::{CustomOnionMessageContents, CustomOnionMessageHandler, SimpleArcOnionMessenger, SimpleRefOnionMessenger};
 use routing::gossip::{NetworkGraph, P2PGossipSync};
 use util::atomic_counter::AtomicCounter;
 use util::crypto::sign;
@@ -95,6 +95,23 @@ impl OnionMessageHandler for IgnoringMessageHandler {
 		InitFeatures::empty()
 	}
 }
+impl CustomOnionMessageHandler for IgnoringMessageHandler {
+	type CustomMessage = Infallible;
+	fn handle_custom_message(&self, _msg: Self::CustomMessage) {
+		// Since we always return `None` in the read the handle method should never be called.
+		unreachable!();
+	}
+}
+impl MaybeReadableArgs<u64> for Infallible {
+	fn read<R: io::Read>(_buffer: &mut R, _msg_type: u64) -> Result<Option<Self>, msgs::DecodeError> where Self: Sized {
+		Ok(None)
+	}
+}
+
+impl CustomOnionMessageContents for Infallible {
+	fn tlv_type(&self) -> u64 { unreachable!(); }
+}
+
 impl Deref for IgnoringMessageHandler {
 	type Target = IgnoringMessageHandler;
 	fn deref(&self) -> &Self { self }

lightning/src/onion_message/functional_tests.rs

@@ -11,19 +11,21 @@
 
 use chain::keysinterface::{KeysInterface, Recipient};
 use ln::features::InitFeatures;
-use ln::msgs::{self, OnionMessageHandler};
-use super::{BlindedRoute, Destination, OnionMessenger, SendError};
+use ln::msgs::{self, DecodeError, OnionMessageHandler};
+use super::{BlindedRoute, CustomOnionMessageContents, CustomOnionMessageHandler, Destination, OnionMessageContents, OnionMessenger, SendError};
 use util::enforcing_trait_impls::EnforcingSigner;
+use util::ser::{MaybeReadableArgs, Writeable, Writer};
 use util::test_utils;
 
 use bitcoin::network::constants::Network;
 use bitcoin::secp256k1::{PublicKey, Secp256k1};
 
+use io;
 use sync::Arc;
 
 struct MessengerNode {
 	keys_manager: Arc<test_utils::TestKeysInterface>,
-	messenger: OnionMessenger<EnforcingSigner, Arc<test_utils::TestKeysInterface>, Arc<test_utils::TestLogger>>,
+	messenger: OnionMessenger<EnforcingSigner, Arc<test_utils::TestKeysInterface>, Arc<test_utils::TestLogger>, Arc<TestCustomMessageHandler>>,
 	logger: Arc<test_utils::TestLogger>,
 }
 
@@ -34,6 +36,43 @@ impl MessengerNode {
 	}
 }
 
+#[derive(Clone)]
+struct TestCustomMessage {}
+
+const CUSTOM_MESSAGE_TYPE: u64 = 4242;
+const CUSTOM_MESSAGE_CONTENTS: [u8; 32] = [42; 32];
+
+impl CustomOnionMessageContents for TestCustomMessage {
+	fn tlv_type(&self) -> u64 {
+		CUSTOM_MESSAGE_TYPE
+	}
+}
+
+impl Writeable for TestCustomMessage {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		Ok(CUSTOM_MESSAGE_CONTENTS.write(w)?)
+	}
+}
+
+impl MaybeReadableArgs<u64> for TestCustomMessage {
+	fn read<R: io::Read>(buffer: &mut R, message_type: u64) -> Result<Option<Self>, DecodeError> where Self: Sized {
+		if message_type == CUSTOM_MESSAGE_TYPE {
+			let mut buf = Vec::new();
+			buffer.read_to_end(&mut buf)?;
+			assert_eq!(buf, CUSTOM_MESSAGE_CONTENTS);
+			return Ok(Some(TestCustomMessage {}))
+		}
+		Ok(None)
+	}
+}
+
+struct TestCustomMessageHandler {}
+
+impl CustomOnionMessageHandler for TestCustomMessageHandler {
+	type CustomMessage = TestCustomMessage;
+	fn handle_custom_message(&self, _msg: Self::CustomMessage) {}
+}
+
 fn create_nodes(num_messengers: u8) -> Vec<MessengerNode> {
 	let mut nodes = Vec::new();
 	for i in 0..num_messengers {
@@ -42,7 +81,7 @@ fn create_nodes(num_messengers: u8) -> Vec<MessengerNode> {
 		let keys_manager = Arc::new(test_utils::TestKeysInterface::new(&seed, Network::Testnet));
 		nodes.push(MessengerNode {
 			keys_manager: keys_manager.clone(),
-			messenger: OnionMessenger::new(keys_manager, logger.clone()),
+			messenger: OnionMessenger::new(keys_manager, logger.clone(), Arc::new(TestCustomMessageHandler {})),
 			logger,
 		});
 	}
@@ -80,103 +119,138 @@ fn pass_along_path(path: &Vec<MessengerNode>, expected_path_id: Option<[u8; 32]>
 #[test]
 fn one_hop() {
 	let nodes = create_nodes(2);
+	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
-	nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), None).unwrap();
+	nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
 }
 
 #[test]
 fn two_unblinded_hops() {
 	let nodes = create_nodes(3);
+	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
-	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk()], Destination::Node(nodes[2].get_node_pk()), None).unwrap();
+	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk()], Destination::Node(nodes[2].get_node_pk()), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
 }
 
 #[test]
 fn two_unblinded_two_blinded() {
 	let nodes = create_nodes(5);
+	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
 	let secp_ctx = Secp256k1::new();
 	let blinded_route = BlindedRoute::new(&[nodes[3].get_node_pk(), nodes[4].get_node_pk()], &*nodes[4].keys_manager, &secp_ctx).unwrap();
 
-	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::BlindedRoute(blinded_route), None).unwrap();
+	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::BlindedRoute(blinded_route), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
 }
 
 #[test]
 fn three_blinded_hops() {
 	let nodes = create_nodes(4);
+	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
 	let secp_ctx = Secp256k1::new();
 	let blinded_route = BlindedRoute::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
 
-	nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), None).unwrap();
+	nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), test_msg, None).unwrap();
 	pass_along_path(&nodes, None);
 }
 
 #[test]
 fn too_big_packet_error() {
 	// Make sure we error as expected if a packet is too big to send.
 	let nodes = create_nodes(2);
+	let test_msg = OnionMessageContents::Custom(TestCustomMessage {});
 
 	let hop_node_id = nodes[1].get_node_pk();
 	let hops = [hop_node_id; 400];
-	let err = nodes[0].messenger.send_onion_message(&hops, Destination::Node(hop_node_id), None).unwrap_err();
+	let err = nodes[0].messenger.send_onion_message(&hops, Destination::Node(hop_node_id), test_msg, None).unwrap_err();
 	assert_eq!(err, SendError::TooBigPacket);
 }
 
 #[test]
 fn invalid_blinded_route_error() {
 	// Make sure we error as expected if a provided blinded route has 0 or 1 hops.
 	let nodes = create_nodes(3);
+	let test_msg = TestCustomMessage {};
 
 	// 0 hops
 	let secp_ctx = Secp256k1::new();
 	let mut blinded_route = BlindedRoute::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
 	blinded_route.blinded_hops.clear();
-	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), None).unwrap_err();
+	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), OnionMessageContents::Custom(test_msg.clone()), None).unwrap_err();
 	assert_eq!(err, SendError::TooFewBlindedHops);
 
 	// 1 hop
 	let mut blinded_route = BlindedRoute::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], &*nodes[2].keys_manager, &secp_ctx).unwrap();
 	blinded_route.blinded_hops.remove(0);
 	assert_eq!(blinded_route.blinded_hops.len(), 1);
-	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), None).unwrap_err();
+	let err = nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), OnionMessageContents::Custom(test_msg), None).unwrap_err();
 	assert_eq!(err, SendError::TooFewBlindedHops);
 }
 
 #[test]
 fn reply_path() {
 	let nodes = create_nodes(4);
+	let test_msg = TestCustomMessage {};
 	let secp_ctx = Secp256k1::new();
 
 	// Destination::Node
 	let reply_path = BlindedRoute::new(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
-	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::Node(nodes[3].get_node_pk()), Some(reply_path)).unwrap();
+	nodes[0].messenger.send_onion_message(&[nodes[1].get_node_pk(), nodes[2].get_node_pk()], Destination::Node(nodes[3].get_node_pk()), OnionMessageContents::Custom(test_msg.clone()), Some(reply_path)).unwrap();
 	pass_along_path(&nodes, None);
 	// Make sure the last node successfully decoded the reply path.
 	nodes[3].logger.assert_log_contains(
 		"lightning::onion_message::messenger".to_string(),
-		format!("Received an onion message with path_id: None and reply_path").to_string(), 1);
+		format!("Received an onion message with path_id None and a reply_path").to_string(), 1);
 
 	// Destination::BlindedRoute
 	let blinded_route = BlindedRoute::new(&[nodes[1].get_node_pk(), nodes[2].get_node_pk(), nodes[3].get_node_pk()], &*nodes[3].keys_manager, &secp_ctx).unwrap();
 	let reply_path = BlindedRoute::new(&[nodes[2].get_node_pk(), nodes[1].get_node_pk(), nodes[0].get_node_pk()], &*nodes[0].keys_manager, &secp_ctx).unwrap();
 
-	nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), Some(reply_path)).unwrap();
+	nodes[0].messenger.send_onion_message(&[], Destination::BlindedRoute(blinded_route), OnionMessageContents::Custom(test_msg), Some(reply_path)).unwrap();
 	pass_along_path(&nodes, None);
 	nodes[3].logger.assert_log_contains(
 		"lightning::onion_message::messenger".to_string(),
-		format!("Received an onion message with path_id: None and reply_path").to_string(), 2);
+		format!("Received an onion message with path_id None and a reply_path").to_string(), 2);
+}
+
+#[test]
+fn invalid_custom_message_type() {
+	let nodes = create_nodes(2);
+
+	struct InvalidCustomMessage{}
+	impl CustomOnionMessageContents for InvalidCustomMessage {
+		fn tlv_type(&self) -> u64 {
+			// Onion message contents must have a TLV >= 64.
+			63
+		}
+	}
+
+	impl Writeable for InvalidCustomMessage {
+		fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> { unreachable!() }
+	}
+
+	impl MaybeReadableArgs<u64> for InvalidCustomMessage {
+		fn read<R: io::Read>(_buffer: &mut R, _message_type: u64) -> Result<Option<Self>, DecodeError> where Self: Sized {
+			unreachable!()
+		}
+	}
+
+	let test_msg = OnionMessageContents::Custom(InvalidCustomMessage {});
+	let err = nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), test_msg, None).unwrap_err();
+	assert_eq!(err, SendError::InvalidMessage);
 }
 
 #[test]
 fn peer_buffer_full() {
 	let nodes = create_nodes(2);
+	let test_msg = TestCustomMessage {};
 	for _ in 0..188 { // Based on MAX_PER_PEER_BUFFER_SIZE in OnionMessenger
-		nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), None).unwrap();
+		nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), OnionMessageContents::Custom(test_msg.clone()), None).unwrap();
 	}
-	let err = nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), None).unwrap_err();
+	let err = nodes[0].messenger.send_onion_message(&[], Destination::Node(nodes[1].get_node_pk()), OnionMessageContents::Custom(test_msg), None).unwrap_err();
 	assert_eq!(err, SendError::BufferFull);
 }