Pass node features through to RouteHops

This exposes the latest Init-context features in the ChannelDetails
passed to the Router during route calculation, which combines those
with the Node-context features tracked from node_announcements to
provide the latest Node-context features in RouteHop structs.

Fields are also added for Channel-context features, though those are
only partially used since no such features are defined today anyway.

These will be useful when determining whether to use new
TLV-formatted onion hop datas when generating onions for peers.

Author: TheBlueMatt

fuzz/src/chanmon_consistency.rs

@@ -422,7 +422,9 @@ pub fn do_test(data: &[u8]) {
 				if let Err(_) = $source.send_payment(Route {
 					hops: vec![RouteHop {
 						pubkey: $dest.0.get_our_node_id(),
+						node_features: Features::empty(),
 						short_channel_id: $dest.1,
+						channel_features: Features::empty(),
 						fee_msat: 5000000,
 						cltv_expiry_delta: 200,
 					}],
@@ -437,12 +439,16 @@ pub fn do_test(data: &[u8]) {
 				if let Err(_) = $source.send_payment(Route {
 					hops: vec![RouteHop {
 						pubkey: $middle.0.get_our_node_id(),
+						node_features: Features::empty(),
 						short_channel_id: $middle.1,
+						channel_features: Features::empty(),
 						fee_msat: 50000,
 						cltv_expiry_delta: 100,
 					},RouteHop {
 						pubkey: $dest.0.get_our_node_id(),
+						node_features: Features::empty(),
 						short_channel_id: $dest.1,
+						channel_features: Features::empty(),
 						fee_msat: 5000000,
 						cltv_expiry_delta: 200,
 					}],

fuzz/src/router.rs

@@ -6,7 +6,7 @@ use bitcoin::blockdata::transaction::Transaction;
 use lightning::chain::chaininterface::{ChainError,ChainWatchInterface};
 use lightning::ln::channelmanager::ChannelDetails;
 use lightning::ln::msgs;
-use lightning::ln::msgs::{RoutingMessageHandler};
+use lightning::ln::msgs::{RoutingMessageHandler, Features};
 use lightning::ln::router::{Router, RouteHint};
 use lightning::util::logger::Logger;
 use lightning::util::ser::Readable;
@@ -198,6 +198,7 @@ pub fn do_test(data: &[u8]) {
 								channel_id: [0; 32],
 								short_channel_id: Some(slice_to_be64(get_slice!(8))),
 								remote_network_id: get_pubkey!(),
+								remote_node_features: Features::empty(),
 								channel_value_satoshis: slice_to_be64(get_slice!(8)),
 								user_id: 0,
 								inbound_capacity_msat: 0,

lightning/src/ln/channelmanager.rs

@@ -422,6 +422,11 @@ pub struct ChannelDetails {
 	pub short_channel_id: Option<u64>,
 	/// The node_id of our counterparty
 	pub remote_network_id: PublicKey,
+	/// The Features this node provided us opon our last connection with them.
+	/// This is particularly useful for routing as many node_announcement-context features are also
+	/// set in the init-context, and we should almost certainly consider the init-context version
+	/// to be the latest copy.
+	pub remote_node_features: Features<FeatureContextInit>,
 	/// The value, in satoshis, of this channel as appears in the funding output
 	pub channel_value_satoshis: u64,
 	/// The user_id passed in to create_channel, or 0 if the channel was inbound.
@@ -694,50 +699,70 @@ impl<ChanSigner: ChannelKeys> ChannelManager<ChanSigner> {
 	/// Gets the list of open channels, in random order. See ChannelDetail field documentation for
 	/// more information.
 	pub fn list_channels(&self) -> Vec<ChannelDetails> {
-		let channel_state = self.channel_state.lock().unwrap();
-		let mut res = Vec::with_capacity(channel_state.by_id.len());
-		for (channel_id, channel) in channel_state.by_id.iter() {
-			let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
-			res.push(ChannelDetails {
-				channel_id: (*channel_id).clone(),
-				short_channel_id: channel.get_short_channel_id(),
-				remote_network_id: channel.get_their_node_id(),
-				channel_value_satoshis: channel.get_value_satoshis(),
-				inbound_capacity_msat,
-				outbound_capacity_msat,
-				user_id: channel.get_user_id(),
-				is_live: channel.is_live(),
-			});
-		}
-		res
-	}
-
-	/// Gets the list of usable channels, in random order. Useful as an argument to
-	/// Router::get_route to ensure non-announced channels are used.
-	///
-	/// These are guaranteed to have their is_live value set to true, see the documentation for
-	/// ChannelDetails::is_live for more info on exactly what the criteria are.
-	pub fn list_usable_channels(&self) -> Vec<ChannelDetails> {
-		let channel_state = self.channel_state.lock().unwrap();
-		let mut res = Vec::with_capacity(channel_state.by_id.len());
-		for (channel_id, channel) in channel_state.by_id.iter() {
-			// Note we use is_live here instead of usable which leads to somewhat confused
-			// internal/external nomenclature, but that's ok cause that's probably what the user
-			// really wanted anyway.
-			if channel.is_live() {
+		let mut res = Vec::new();
+		{
+			let channel_state = self.channel_state.lock().unwrap();
+			res.reserve(channel_state.by_id.len());
+			for (channel_id, channel) in channel_state.by_id.iter() {
 				let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
 				res.push(ChannelDetails {
 					channel_id: (*channel_id).clone(),
 					short_channel_id: channel.get_short_channel_id(),
 					remote_network_id: channel.get_their_node_id(),
+					remote_node_features: Features::empty(),
 					channel_value_satoshis: channel.get_value_satoshis(),
 					inbound_capacity_msat,
 					outbound_capacity_msat,
 					user_id: channel.get_user_id(),
-					is_live: true,
+					is_live: channel.is_live(),
 				});
 			}
 		}
+		let per_peer_state = self.per_peer_state.read().unwrap();
+		for chan in res.iter_mut() {
+			if let Some(peer_state) = per_peer_state.get(&chan.remote_network_id) {
+				chan.remote_node_features = peer_state.lock().unwrap().latest_features.clone();
+			}
+		}
+		res
+	}
+
+	/// Gets the list of usable channels, in random order. Useful as an argument to
+	/// Router::get_route to ensure non-announced channels are used.
+	///
+	/// These are guaranteed to have their is_live value set to true, see the documentation for
+	/// ChannelDetails::is_live for more info on exactly what the criteria are.
+	pub fn list_usable_channels(&self) -> Vec<ChannelDetails> {
+		let mut res = Vec::new();
+		{
+			let channel_state = self.channel_state.lock().unwrap();
+			res.reserve(channel_state.by_id.len());
+			for (channel_id, channel) in channel_state.by_id.iter() {
+				// Note we use is_live here instead of usable which leads to somewhat confused
+				// internal/external nomenclature, but that's ok cause that's probably what the user
+				// really wanted anyway.
+				if channel.is_live() {
+					let (inbound_capacity_msat, outbound_capacity_msat) = channel.get_inbound_outbound_available_balance_msat();
+					res.push(ChannelDetails {
+						channel_id: (*channel_id).clone(),
+						short_channel_id: channel.get_short_channel_id(),
+						remote_network_id: channel.get_their_node_id(),
+						remote_node_features: Features::empty(),
+						channel_value_satoshis: channel.get_value_satoshis(),
+						inbound_capacity_msat,
+						outbound_capacity_msat,
+						user_id: channel.get_user_id(),
+						is_live: true,
+					});
+				}
+			}
+		}
+		let per_peer_state = self.per_peer_state.read().unwrap();
+		for chan in res.iter_mut() {
+			if let Some(peer_state) = per_peer_state.get(&chan.remote_network_id) {
+				chan.remote_node_features = peer_state.lock().unwrap().latest_features.clone();
+			}
+		}
 		res
 	}
 

lightning/src/ln/functional_tests.rs

@@ -1022,19 +1022,25 @@ fn fake_network_test() {
 	let mut hops = Vec::with_capacity(3);
 	hops.push(RouteHop {
 		pubkey: nodes[2].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_2.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 0,
 		cltv_expiry_delta: chan_3.0.contents.cltv_expiry_delta as u32
 	});
 	hops.push(RouteHop {
 		pubkey: nodes[3].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_3.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 0,
 		cltv_expiry_delta: chan_4.1.contents.cltv_expiry_delta as u32
 	});
 	hops.push(RouteHop {
 		pubkey: nodes[1].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_4.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 1000000,
 		cltv_expiry_delta: TEST_FINAL_CLTV,
 	});
@@ -1045,19 +1051,25 @@ fn fake_network_test() {
 	let mut hops = Vec::with_capacity(3);
 	hops.push(RouteHop {
 		pubkey: nodes[3].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_4.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 0,
 		cltv_expiry_delta: chan_3.1.contents.cltv_expiry_delta as u32
 	});
 	hops.push(RouteHop {
 		pubkey: nodes[2].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_3.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 0,
 		cltv_expiry_delta: chan_2.1.contents.cltv_expiry_delta as u32
 	});
 	hops.push(RouteHop {
 		pubkey: nodes[1].node.get_our_node_id(),
+		node_features: Features::empty(),
 		short_channel_id: chan_2.0.contents.short_channel_id,
+		channel_features: Features::empty(),
 		fee_msat: 1000000,
 		cltv_expiry_delta: TEST_FINAL_CLTV,
 	});

lightning/src/ln/msgs.rs

@@ -110,7 +110,11 @@ pub struct Features<T: FeatureContext> {
 	// Used to test encoding of diverse msgs
 	#[cfg(test)]
 	pub flags: Vec<u8>,
+
+	#[cfg(not(test))]
 	mark: PhantomData<T>,
+	#[cfg(test)]
+	pub mark: PhantomData<T>,
 }
 
 impl<T: FeatureContext> Clone for Features<T> {
@@ -207,6 +211,28 @@ impl<T: FeatureContext> Features<T> {
 	}
 }
 
+impl Features<FeatureContextNode> {
+	/// Takes the flags that we know how to interpret in an init-context features that are also
+	/// relevant in a node-context features and creates a node-context features from them.
+	pub(crate) fn relevant_init_flags_to_node(init_ctx: &Features<FeatureContextInit>) -> Self {
+		let mut flags = Vec::new();
+		if init_ctx.flags.len() > 0 {
+			// Pull out data_loss_protect and upfront_shutdown_script (bits 0, 1, 4, and 5)
+			flags.push(init_ctx.flags.last().unwrap() & 0b00110011);
+		}
+		Self { flags, mark: PhantomData, }
+	}
+}
+
+impl Features<FeatureContextChannel> {
+	/// Takes the flags that we know how to interpret in an init-context features that are also
+	/// relevant in a channel-context features and creates a channel-context features from them.
+	pub(crate) fn relevant_init_flags_to_channel(_init_ctx: &Features<FeatureContextInit>) -> Self {
+		// There are currently no channel flags defined that we understand.
+		Self { flags: Vec::new(), mark: PhantomData, }
+	}
+}
+
 impl<T: FeatureContextInitNode> Features<T> {
 	pub(crate) fn supports_data_loss_protect(&self) -> bool {
 		self.flags.len() > 0 && (self.flags[0] & 3) != 0

lightning/src/ln/onion_utils.rs

@@ -444,22 +444,27 @@ mod tests {
 			hops: vec!(
 					RouteHop {
 						pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
+						channel_features: msgs::Features::empty(), node_features: msgs::Features::empty(),
 						short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually
 					},
 					RouteHop {
 						pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
+						channel_features: msgs::Features::empty(), node_features: msgs::Features::empty(),
 						short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually
 					},
 					RouteHop {
 						pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
+						channel_features: msgs::Features::empty(), node_features: msgs::Features::empty(),
 						short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually
 					},
 					RouteHop {
 						pubkey: PublicKey::from_slice(&hex::decode("032c0b7cf95324a07d05398b240174dc0c2be444d96b159aa6c7f7b1e668680991").unwrap()[..]).unwrap(),
+						channel_features: msgs::Features::empty(), node_features: msgs::Features::empty(),
 						short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually
 					},
 					RouteHop {
 						pubkey: PublicKey::from_slice(&hex::decode("02edabbd16b41c8371b92ef2f04c1185b4f03b6dcd52ba9b78d9d7c89c8f221145").unwrap()[..]).unwrap(),
+						channel_features: msgs::Features::empty(), node_features: msgs::Features::empty(),
 						short_channel_id: 0, fee_msat: 0, cltv_expiry_delta: 0 // Test vectors are garbage and not generateble from a RouteHop, we fill in payloads manually
 					},
 			),