Onion messages: flip feature bit 🎉

lightning-net-tokio/src/lib.rs

@@ -582,6 +582,7 @@ mod tests {
 		fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
 		fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
 		fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: QueryShortChannelIds) -> Result<(), LightningError> { Ok(()) }
+		fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::known() }
 		fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::known() }
 	}
 	impl ChannelMessageHandler for MsgHandler {

lightning/src/ln/channelmanager.rs

@@ -6122,7 +6122,7 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
 	}
 
 	fn provided_node_features(&self) -> NodeFeatures {
-		NodeFeatures::known()
+		NodeFeatures::known_channel_features()
 	}
 
 	fn provided_init_features(&self, _their_init_features: &PublicKey) -> InitFeatures {

lightning/src/ln/features.rs

@@ -39,8 +39,13 @@
 //!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md) for more information).
 //! - `BasicMPP` - requires/supports that a node can receive basic multi-part payments
 //!     (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md#basic-multi-part-payments) for more information).
+//! - `Wumbo` - requires/supports that a node create large channels. Called `option_support_large_channel` in the spec.
+//!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) for more information).
 //! - `ShutdownAnySegwit` - requires/supports that future segwit versions are allowed in `shutdown`
 //!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
+//! - `OnionMessages` - requires/supports forwarding onion messages
+//!     (see [BOLT-7](https://github.com/lightning/bolts/pull/759/files) for more information).
+//!     TODO: update link
 //! - `ChannelType` - node supports the channel_type field in open/accept
 //!     (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
 //! - `SCIDPrivacy` - supply channel aliases for routing
@@ -164,7 +169,8 @@ mod sealed {
 		],
 		optional_features: [
 			// Note that if new "non-channel-related" flags are added here they should be
-			// explicitly cleared in InitFeatures::known_channel_features.
+			// explicitly cleared in InitFeatures::known_channel_features and
+			// NodeFeatures::known_channel_features.
 			// Byte 0
 			DataLossProtect | InitialRoutingSync | UpfrontShutdownScript | GossipQueries,
 			// Byte 1
@@ -174,7 +180,7 @@ mod sealed {
 			// Byte 3
 			ShutdownAnySegwit,
 			// Byte 4
-			,
+			OnionMessages,
 			// Byte 5
 			ChannelType | SCIDPrivacy,
 			// Byte 6
@@ -208,7 +214,7 @@ mod sealed {
 			// Byte 3
 			ShutdownAnySegwit,
 			// Byte 4
-			,
+			OnionMessages,
 			// Byte 5
 			ChannelType | SCIDPrivacy,
 			// Byte 6
@@ -435,8 +441,6 @@ mod sealed {
 	define_feature!(27, ShutdownAnySegwit, [InitContext, NodeContext],
 		"Feature flags for `opt_shutdown_anysegwit`.", set_shutdown_any_segwit_optional,
 		set_shutdown_any_segwit_required, supports_shutdown_anysegwit, requires_shutdown_anysegwit);
-	// We do not yet advertise the onion messages feature bit, but we need to detect when peers
-	// support it.
 	define_feature!(39, OnionMessages, [InitContext, NodeContext],
 		"Feature flags for `option_onion_messages`.", set_onion_messages_optional,
 		set_onion_messages_required, supports_onion_messages, requires_onion_messages);
@@ -470,6 +474,17 @@ pub struct Features<T: sealed::Context> {
 	mark: PhantomData<T>,
 }
 
+impl <T: sealed::Context> Features<T> {
+	pub(crate) fn or(mut self, o: Self) -> Self {
+		let total_feature_len = cmp::max(self.flags.len(), o.flags.len());
+		self.flags.resize(total_feature_len, 0u8);
+		for (byte, o_byte) in self.flags.iter_mut().zip(o.flags.iter()) {
+			*byte |= *o_byte;
+		}
+		self
+	}
+}
+
 impl<T: sealed::Context> Clone for Features<T> {
 	fn clone(&self) -> Self {
 		Self {
@@ -532,16 +547,6 @@ impl InitFeatures {
 		Ok(())
 	}
 
-	/// or's another InitFeatures into this one.
-	pub(crate) fn or(mut self, o: InitFeatures) -> InitFeatures {
-		let total_feature_len = cmp::max(self.flags.len(), o.flags.len());
-		self.flags.resize(total_feature_len, 0u8);
-		for (byte, o_byte) in self.flags.iter_mut().zip(o.flags.iter()) {
-			*byte |= *o_byte;
-		}
-		self
-	}
-
 	/// Converts `InitFeatures` to `Features<C>`. Only known `InitFeatures` relevant to context `C`
 	/// are included in the result.
 	pub(crate) fn to_context<C: sealed::Context>(&self) -> Features<C> {
@@ -554,6 +559,16 @@ impl InitFeatures {
 		Self::known()
 			.clear_initial_routing_sync()
 			.clear_gossip_queries()
+			.clear_onion_messages()
+	}
+}
+
+impl NodeFeatures {
+	/// Returns the set of known node features that are related to channels.
+	pub fn known_channel_features() -> NodeFeatures {
+		Self::known()
+			.clear_gossip_queries()
+			.clear_onion_messages()
 	}
 }
 
@@ -787,6 +802,13 @@ impl<T: sealed::InitialRoutingSync> Features<T> {
 	}
 }
 
+impl<T: sealed::OnionMessages> Features<T> {
+	pub(crate) fn clear_onion_messages(mut self) -> Self {
+		<T as sealed::OnionMessages>::clear_bits(&mut self.flags);
+		self
+	}
+}
+
 impl<T: sealed::ShutdownAnySegwit> Features<T> {
 	#[cfg(test)]
 	pub(crate) fn clear_shutdown_anysegwit(mut self) -> Self {
@@ -913,6 +935,11 @@ mod tests {
 		assert!(!InitFeatures::known().requires_wumbo());
 		assert!(!NodeFeatures::known().requires_wumbo());
 
+		assert!(InitFeatures::known().supports_onion_messages());
+		assert!(NodeFeatures::known().supports_onion_messages());
+		assert!(!InitFeatures::known().requires_onion_messages());
+		assert!(!NodeFeatures::known().requires_onion_messages());
+
 		assert!(InitFeatures::known().supports_zero_conf());
 		assert!(!InitFeatures::known().requires_zero_conf());
 		assert!(NodeFeatures::known().supports_zero_conf());
@@ -957,15 +984,15 @@ mod tests {
 			// - var_onion_optin (req) | static_remote_key (req) | payment_secret(req)
 			// - basic_mpp | wumbo
 			// - opt_shutdown_anysegwit
-			// -
+			// - onion_messages
 			// - option_channel_type | option_scid_alias
 			// - option_zeroconf
 			assert_eq!(node_features.flags.len(), 7);
 			assert_eq!(node_features.flags[0], 0b00000010);
 			assert_eq!(node_features.flags[1], 0b01010001);
 			assert_eq!(node_features.flags[2], 0b00001010);
 			assert_eq!(node_features.flags[3], 0b00001000);
-			assert_eq!(node_features.flags[4], 0b00000000);
+			assert_eq!(node_features.flags[4], 0b10000000);
 			assert_eq!(node_features.flags[5], 0b10100000);
 			assert_eq!(node_features.flags[6], 0b00001000);
 		}

lightning/src/ln/msgs.rs

@@ -900,7 +900,7 @@ pub trait ChannelMessageHandler : MessageSendEventsProvider {
 	// Handler information:
 	/// Gets the node feature flags which this handler itself supports. All available handlers are
 	/// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
-	/// which are broadcasted in our node_announcement message.
+	/// which are broadcasted in our [`NodeAnnouncement`] message.
 	fn provided_node_features(&self) -> NodeFeatures;
 
 	/// Gets the init feature flags which should be sent to the given peer. All available handlers
@@ -958,6 +958,10 @@ pub trait RoutingMessageHandler : MessageSendEventsProvider {
 	fn handle_query_short_channel_ids(&self, their_node_id: &PublicKey, msg: QueryShortChannelIds) -> Result<(), LightningError>;
 
 	// Handler information:
+	/// Gets the node feature flags which this handler itself supports. All available handlers are
+	/// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
+	/// which are broadcasted in our [`NodeAnnouncement`] message.
+	fn provided_node_features(&self) -> NodeFeatures;
 	/// Gets the init feature flags which should be sent to the given peer. All available handlers
 	/// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
 	/// which are sent in our [`Init`] message.
@@ -976,6 +980,19 @@ pub trait OnionMessageHandler : OnionMessageProvider {
 	/// Indicates a connection to the peer failed/an existing connection was lost. Allows handlers to
 	/// drop and refuse to forward onion messages to this peer.
 	fn peer_disconnected(&self, their_node_id: &PublicKey, no_connection_possible: bool);
+
+	// Handler information:
+	/// Gets the node feature flags which this handler itself supports. All available handlers are
+	/// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
+	/// which are broadcasted in our [`NodeAnnouncement`] message.
+	fn provided_node_features(&self) -> NodeFeatures;
+
+	/// Gets the init feature flags which should be sent to the given peer. All available handlers
+	/// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
+	/// which are sent in our [`Init`] message.
+	///
+	/// Note that this method is called before [`Self::peer_connected`].
+	fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
 }
 
 mod fuzzy_internal_msgs {

lightning/src/ln/peer_handler.rs

@@ -77,6 +77,7 @@ impl RoutingMessageHandler for IgnoringMessageHandler {
 	fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: msgs::ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
 	fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: msgs::QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
 	fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: msgs::QueryShortChannelIds) -> Result<(), LightningError> { Ok(()) }
+	fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
 	fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
 		InitFeatures::empty()
 	}
@@ -88,6 +89,10 @@ impl OnionMessageHandler for IgnoringMessageHandler {
 	fn handle_onion_message(&self, _their_node_id: &PublicKey, _msg: &msgs::OnionMessage) {}
 	fn peer_connected(&self, _their_node_id: &PublicKey, _init: &msgs::Init) {}
 	fn peer_disconnected(&self, _their_node_id: &PublicKey, _no_connection_possible: bool) {}
+	fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
+	fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
+		InitFeatures::empty()
+	}
 }
 impl Deref for IgnoringMessageHandler {
 	type Target = IgnoringMessageHandler;
@@ -1061,7 +1066,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 								peer.their_node_id = Some(their_node_id);
 								insert_node_id!();
 								let features = self.message_handler.chan_handler.provided_init_features(&their_node_id)
-									.or(self.message_handler.route_handler.provided_init_features(&their_node_id));
+									.or(self.message_handler.route_handler.provided_init_features(&their_node_id))
+									.or(self.message_handler.onion_message_handler.provided_init_features(&their_node_id));
 								let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
 								self.enqueue_message(peer, &resp);
 								peer.awaiting_pong_timer_tick_intervals = 0;
@@ -1074,7 +1080,8 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 								peer.their_node_id = Some(their_node_id);
 								insert_node_id!();
 								let features = self.message_handler.chan_handler.provided_init_features(&their_node_id)
-									.or(self.message_handler.route_handler.provided_init_features(&their_node_id));
+									.or(self.message_handler.route_handler.provided_init_features(&their_node_id))
+									.or(self.message_handler.onion_message_handler.provided_init_features(&their_node_id));
 								let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
 								self.enqueue_message(peer, &resp);
 								peer.awaiting_pong_timer_tick_intervals = 0;
@@ -1969,8 +1976,11 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 		// addresses be sorted for future compatibility.
 		addresses.sort_by_key(|addr| addr.get_id());
 
+		let features = self.message_handler.chan_handler.provided_node_features()
+			.or(self.message_handler.route_handler.provided_node_features())
+			.or(self.message_handler.onion_message_handler.provided_node_features());
 		let announcement = msgs::UnsignedNodeAnnouncement {
-			features: self.message_handler.chan_handler.provided_node_features(),
+			features,
 			timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel) as u32,
 			node_id: PublicKey::from_secret_key(&self.secp_ctx, &self.our_node_secret),
 			rgb, alias, addresses,

lightning/src/onion_message/messenger.rs

@@ -16,6 +16,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, PublicKey, Scalar, Secp256k1, SecretKey};
 
 use chain::keysinterface::{InMemorySigner, KeysInterface, KeysManager, Recipient, Sign};
+use ln::features::{InitFeatures, NodeFeatures};
 use ln::msgs::{self, OnionMessageHandler};
 use ln::onion_utils;
 use super::blinded_route::{BlindedRoute, ForwardTlvs, ReceiveTlvs};
@@ -345,6 +346,18 @@ impl<Signer: Sign, K: Deref, L: Deref> OnionMessageHandler for OnionMessenger<Si
 		let mut pending_msgs = self.pending_messages.lock().unwrap();
 		pending_msgs.remove(their_node_id);
 	}
+
+	fn provided_node_features(&self) -> NodeFeatures {
+		let mut features = NodeFeatures::empty();
+		features.set_onion_messages_optional();
+		features
+	}
+
+	fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
+		let mut features = InitFeatures::empty();
+		features.set_onion_messages_optional();
+		features
+	}
 }
 
 impl<Signer: Sign, K: Deref, L: Deref> OnionMessageProvider for OnionMessenger<Signer, K, L>

lightning/src/routing/gossip.rs

@@ -571,6 +571,12 @@ where C::Target: chain::Access, L::Target: Logger
 		})
 	}
 
+	fn provided_node_features(&self) -> NodeFeatures {
+		let mut features = NodeFeatures::empty();
+		features.set_gossip_queries_optional();
+		features
+	}
+
 	fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures {
 		let mut features = InitFeatures::empty();
 		features.set_gossip_queries_optional();

lightning/src/util/test_utils.rs

@@ -358,7 +358,7 @@ impl msgs::ChannelMessageHandler for TestChannelMessageHandler {
 		self.received_msg(wire::Message::Error(msg.clone()));
 	}
 	fn provided_node_features(&self) -> NodeFeatures {
-		NodeFeatures::empty()
+		NodeFeatures::known_channel_features()
 	}
 	fn provided_init_features(&self, _their_init_features: &PublicKey) -> InitFeatures {
 		InitFeatures::known_channel_features()
@@ -511,6 +511,12 @@ impl msgs::RoutingMessageHandler for TestRoutingMessageHandler {
 		Ok(())
 	}
 
+	fn provided_node_features(&self) -> NodeFeatures {
+		let mut features = NodeFeatures::empty();
+		features.set_gossip_queries_optional();
+		features
+	}
+
 	fn provided_init_features(&self, _their_init_features: &PublicKey) -> InitFeatures {
 		let mut features = InitFeatures::empty();
 		features.set_gossip_queries_optional();