Support forwarding blinded HTLCs as non-intro node.

Error handling will be completed in upcoming commit(s).

Author: valentinewallace

lightning/src/ln/msgs.rs

@@ -1714,7 +1714,7 @@ mod fuzzy_internal_msgs {
 			payment_relay: PaymentRelay,
 			payment_constraints: PaymentConstraints,
 			features: BlindedHopFeatures,
-			intro_node_blinding_point: PublicKey,
+			intro_node_blinding_point: Option<PublicKey>,
 		},
 		BlindedReceive {
 			sender_intended_htlc_amt_msat: u64,
@@ -2394,7 +2394,7 @@ impl<NS: Deref> ReadableArgs<(Option<PublicKey>, &NS)> for InboundOnionPayload w
 						payment_relay,
 						payment_constraints,
 						features,
-						intro_node_blinding_point: intro_node_blinding_point.ok_or(DecodeError::InvalidValue)?,
+						intro_node_blinding_point,
 					})
 				},
 				ChaChaPolyReadAdapter { readable: BlindedPaymentTlvs::Receive(ReceiveTlvs {

lightning/src/ln/onion_payment.rs

@@ -73,7 +73,7 @@ pub(super) fn create_fwd_pending_htlc_info(
 	};
 
 	let (
-		short_channel_id, amt_to_forward, outgoing_cltv_value, inbound_blinding_point
+		short_channel_id, amt_to_forward, outgoing_cltv_value, intro_node_blinding_point
 	) = match hop_data {
 		msgs::InboundOnionPayload::Forward { short_channel_id, amt_to_forward, outgoing_cltv_value } =>
 			(short_channel_id, amt_to_forward, outgoing_cltv_value, None),
@@ -91,7 +91,7 @@ pub(super) fn create_fwd_pending_htlc_info(
 					err_data: vec![0; 32],
 				}
 			})?;
-			(short_channel_id, amt_to_forward, outgoing_cltv_value, Some(intro_node_blinding_point))
+			(short_channel_id, amt_to_forward, outgoing_cltv_value, intro_node_blinding_point)
 		},
 		msgs::InboundOnionPayload::Receive { .. } | msgs::InboundOnionPayload::BlindedReceive { .. } =>
 			return Err(InboundHTLCErr {
@@ -105,7 +105,8 @@ pub(super) fn create_fwd_pending_htlc_info(
 		routing: PendingHTLCRouting::Forward {
 			onion_packet: outgoing_packet,
 			short_channel_id,
-			blinded: inbound_blinding_point.map(|bp| BlindedForward { inbound_blinding_point: bp }),
+			blinded: intro_node_blinding_point.or(msg.blinding_point)
+				.map(|bp| BlindedForward { inbound_blinding_point: bp }),
 		},
 		payment_hash: msg.payment_hash,
 		incoming_shared_secret: shared_secret,