Parse inbound TrampolineEntrypoint payload

Author: arik-so

lightning/src/ln/msgs.rs

@@ -1766,6 +1766,13 @@ mod fuzzy_internal_msgs {
 			amt_to_forward: u64,
 			outgoing_cltv_value: u32,
 		},
+		#[allow(unused)]
+		TrampolineEntrypoint {
+			amt_to_forward: u64,
+			outgoing_cltv_value: u32,
+			multipath_trampoline_data: Option<FinalOnionHopData>,
+			trampoline_packet: TrampolineOnionPacket,
+		},
 		Receive {
 			payment_data: Option<FinalOnionHopData>,
 			payment_metadata: Option<Vec<u8>>,
@@ -2848,6 +2855,7 @@ impl<NS: Deref> ReadableArgs<(Option<PublicKey>, NS)> for InboundOnionPayload wh
 		let mut payment_metadata: Option<WithoutLength<Vec<u8>>> = None;
 		let mut total_msat = None;
 		let mut keysend_preimage: Option<PaymentPreimage> = None;
+		let mut trampoline_onion_packet: Option<TrampolineOnionPacket> = None;
 		let mut custom_tlvs = Vec::new();
 
 		let tlv_len = BigSize::read(r)?;
@@ -2861,6 +2869,7 @@ impl<NS: Deref> ReadableArgs<(Option<PublicKey>, NS)> for InboundOnionPayload wh
 			(12, intro_node_blinding_point, option),
 			(16, payment_metadata, option),
 			(18, total_msat, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
+			(20, trampoline_onion_packet, option),
 			// See https://github.com/lightning/blips/blob/master/blip-0003.md
 			(5482373484, keysend_preimage, option)
 		}, |msg_type: u64, msg_reader: &mut FixedLengthReader<_>| -> Result<bool, DecodeError> {
@@ -2937,6 +2946,16 @@ impl<NS: Deref> ReadableArgs<(Option<PublicKey>, NS)> for InboundOnionPayload wh
 				amt_to_forward: amt.ok_or(DecodeError::InvalidValue)?,
 				outgoing_cltv_value: cltv_value.ok_or(DecodeError::InvalidValue)?,
 			})
+		} else if let Some(trampoline_onion_packet) = trampoline_onion_packet {
+			if payment_metadata.is_some() || encrypted_tlvs_opt.is_some() ||
+				total_msat.is_some()
+			{ return Err(DecodeError::InvalidValue) }
+			Ok(Self::TrampolineEntrypoint {
+				amt_to_forward: amt.ok_or(DecodeError::InvalidValue)?,
+				outgoing_cltv_value: cltv_value.ok_or(DecodeError::InvalidValue)?,
+				multipath_trampoline_data: payment_data,
+				trampoline_packet: trampoline_onion_packet,
+			})
 		} else {
 			if encrypted_tlvs_opt.is_some() || total_msat.is_some() {
 				return Err(DecodeError::InvalidValue)

lightning/src/ln/onion_payment.rs

@@ -99,6 +99,9 @@ pub(super) fn create_fwd_pending_htlc_info(
 			(short_channel_id, amt_to_forward, outgoing_cltv_value, intro_node_blinding_point,
 			 next_blinding_override)
 		},
+		msgs::InboundOnionPayload::TrampolineEntrypoint {..} => {
+			todo!()
+		},
 		msgs::InboundOnionPayload::Receive { .. } | msgs::InboundOnionPayload::BlindedReceive { .. } =>
 			return Err(InboundHTLCErr {
 				msg: "Final Node OnionHopData provided for us as an intermediary node",
@@ -165,6 +168,9 @@ pub(super) fn create_recv_pending_htlc_info(
 			 sender_intended_htlc_amt_msat, cltv_expiry_height, None, Some(payment_context),
 			 intro_node_blinding_point.is_none(), true)
 		}
+		msgs::InboundOnionPayload::TrampolineEntrypoint { .. } => {
+			todo!()
+		},
 		msgs::InboundOnionPayload::Forward { .. } => {
 			return Err(InboundHTLCErr {
 				err_code: 0x4000|22,
@@ -469,6 +475,14 @@ where
 				outgoing_cltv_value
 			}
 		},
+		onion_utils::Hop::Forward {
+			next_hop_data: msgs::InboundOnionPayload::TrampolineEntrypoint { .. }, ..
+		} => {
+			return_err!("TrampolineEntrypoint data provided in intermediary node", 0x4000 | 22, &[0; 0]);
+		},
+		onion_utils::Hop::Receive(msgs::InboundOnionPayload::TrampolineEntrypoint { .. }) => {
+			todo!()
+		}
 		onion_utils::Hop::Receive { .. } => return Ok((next_hop, shared_secret, None)),
 		onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionPayload::Receive { .. }, .. } |
 			onion_utils::Hop::Forward { next_hop_data: msgs::InboundOnionPayload::BlindedReceive { .. }, .. } =>