Check for mpp support when routing to blinded payees

Author: valentinewallace

lightning/src/ln/features.rs

@@ -792,6 +792,7 @@ impl_feature_len_prefixed_write!(ChannelFeatures);
 impl_feature_len_prefixed_write!(NodeFeatures);
 impl_feature_len_prefixed_write!(InvoiceFeatures);
 impl_feature_len_prefixed_write!(BlindedHopFeatures);
+impl_feature_len_prefixed_write!(Bolt12InvoiceFeatures);
 
 // Some features only appear inside of TLVs, so they don't have a length prefix when serialized.
 macro_rules! impl_feature_tlv_write {

lightning/src/routing/router.rs

@@ -16,7 +16,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use crate::blinded_path::{BlindedHop, BlindedPath};
 use crate::ln::PaymentHash;
 use crate::ln::channelmanager::{ChannelDetails, PaymentId};
-use crate::ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
+use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
 use crate::offers::invoice::BlindedPayInfo;
 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
@@ -536,7 +536,7 @@ impl Writeable for PaymentParameters {
 		let mut blinded_hints = &vec![];
 		match &self.payee {
 			Payee::Clear { route_hints, .. } => clear_hints = route_hints,
-			Payee::Blinded(hints) => blinded_hints = hints,
+			Payee::Blinded { route_hints, .. } => blinded_hints = route_hints,
 		}
 		write_tlv_fields!(writer, {
 			(0, self.payee.node_id(), option),
@@ -549,6 +549,7 @@ impl Writeable for PaymentParameters {
 			(7, self.previously_failed_channels, vec_type),
 			(8, *blinded_hints, optional_vec),
 			(9, self.payee.final_cltv_expiry_delta(), option),
+			(10, self.payee.bolt12_features(), option),
 		});
 		Ok(())
 	}
@@ -567,12 +568,13 @@ impl ReadableArgs<u32> for PaymentParameters {
 			(7, previously_failed_channels, vec_type),
 			(8, blinded_route_hints, optional_vec),
 			(9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
+			(10, bolt12_features, option),
 		});
 		let clear_route_hints = route_hints.unwrap_or(vec![]);
 		let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
 		let payee = if blinded_route_hints.len() != 0 {
 			if clear_route_hints.len() != 0 || payee_pubkey.is_some() { return Err(DecodeError::InvalidValue) }
-			Payee::Blinded(blinded_route_hints)
+			Payee::Blinded { route_hints: blinded_route_hints, features: bolt12_features }
 		} else {
 			Payee::Clear {
 				route_hints: clear_route_hints,
@@ -620,7 +622,7 @@ impl PaymentParameters {
 	/// Creates parameters for paying to a blinded payee.
 	pub fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
 		Self {
-			payee: Payee::Blinded(blinded_route_hints),
+			payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
 			expiry_time: None,
 			max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
 			max_path_count: DEFAULT_MAX_PATH_COUNT,
@@ -629,13 +631,25 @@ impl PaymentParameters {
 		}
 	}
 
+	/// Includes the payee's features. Errors if the parameters were not initialized with
+	/// [`PaymentParameters::blinded`].
+	///
+	/// This is not exported to bindings users since bindings don't support move semantics
+	pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
+		match self.payee {
+			Payee::Clear { .. } => Err(()),
+			Payee::Blinded { route_hints, .. } =>
+				Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
+		}
+	}
+
 	/// Includes the payee's features. Errors if the parameters were initialized with blinded payment
 	/// paths.
 	///
 	/// This is not exported to bindings users since bindings don't support move semantics
 	pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
 		match self.payee {
-			Payee::Blinded(_) => Err(()),
+			Payee::Blinded { .. } => Err(()),
 			Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
 				Ok(Self {
 					payee: Payee::Clear {
@@ -651,7 +665,7 @@ impl PaymentParameters {
 	/// This is not exported to bindings users since bindings don't support move semantics
 	pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
 		match self.payee {
-			Payee::Blinded(_) => Err(()),
+			Payee::Blinded { .. } => Err(()),
 			Payee::Clear { node_id, features, final_cltv_expiry_delta, .. } =>
 				Ok(Self {
 					payee: Payee::Clear {
@@ -696,7 +710,16 @@ impl PaymentParameters {
 pub enum Payee {
 	/// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
 	/// will be included in the final [`Route`].
-	Blinded(Vec<(BlindedPayInfo, BlindedPath)>),
+	Blinded {
+		/// Aggregated routing info and blinded paths, for routing to the payee without knowing their
+		/// node id.
+		route_hints: Vec<(BlindedPayInfo, BlindedPath)>,
+		/// Features supported by the payee.
+		///
+		/// May be set from the payee's invoice. May be `None` if the invoice does not contain any
+		/// features.
+		features: Option<Bolt12InvoiceFeatures>,
+	},
 	/// The recipient included these route hints in their BOLT11 invoice.
 	Clear {
 		/// The node id of the payee.
@@ -722,6 +745,12 @@ impl Payee {
 			_ => None,
 		}
 	}
+	fn bolt12_features(&self) -> &Option<Bolt12InvoiceFeatures> {
+		match self {
+			Self::Blinded { features, .. } => features,
+			_ => &None,
+		}
+	}
 	fn bolt11_features(&self) -> &Option<InvoiceFeatures> {
 		match self {
 			Self::Clear { features, .. } => features,
@@ -736,14 +765,14 @@ impl Payee {
 	}
 	fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
 		match self {
-			Self::Blinded(hints) => &hints[..],
+			Self::Blinded { route_hints, .. } => &route_hints[..],
 			Self::Clear { .. } => &[]
 		}
 	}
 
 	fn clear_route_hints(&self) -> &[RouteHint] {
 		match self {
-			Self::Blinded(_) => &[],
+			Self::Blinded { .. } => &[],
 			Self::Clear { route_hints, .. } => &route_hints[..]
 		}
 	}
@@ -1210,8 +1239,8 @@ where L::Target: Logger {
 				}
 			}
 		},
-		Payee::Blinded(hints) => {
-			for (_, blinded_path) in hints.iter() {
+		Payee::Blinded { route_hints, .. } => {
+			for (_, blinded_path) in route_hints.iter() {
 				if blinded_path.blinded_hops.len() == 0 {
 					return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
 				} else if &blinded_path.introduction_node_id == our_node_pubkey {
@@ -1302,6 +1331,8 @@ where L::Target: Logger {
 		false
 	} else if let Some(features) = payment_params.payee.bolt11_features() {
 		features.supports_basic_mpp()
+	} else if let Some(features) = payment_params.payee.bolt12_features() {
+		features.supports_basic_mpp()
 	} else if let Some(payee) = payee_node_id {
 		network_nodes.get(&payee).map_or(false, |node| node.announcement_info.as_ref().map_or(false,
 			|info| info.features.supports_basic_mpp()))