Move Trampoline data to separate enum variant on OutboundOnionPayload.

Author: arik-so

lightning/src/ln/msgs.rs

@@ -1698,14 +1698,19 @@ mod fuzzy_internal_msgs {
 			amt_to_forward: u64,
 			outgoing_cltv_value: u32,
 		},
+		TrampolineEntry {
+			amt_to_forward: u64,
+			outgoing_cltv_value: u32,
+			payment_data: Option<FinalOnionHopData>,
+			trampoline_packet: crate::onion_message::packet::Packet
+		},
 		Receive {
 			payment_data: Option<FinalOnionHopData>,
 			payment_metadata: Option<Vec<u8>>,
 			keysend_preimage: Option<PaymentPreimage>,
 			custom_tlvs: Vec<(u64, Vec<u8>)>,
 			sender_intended_htlc_amt_msat: u64,
 			cltv_expiry_height: u32,
-			trampoline_packet: Option<crate::onion_message::packet::Packet>
 		},
 		BlindedForward {
 			encrypted_tlvs: Vec<u8>,
@@ -2479,9 +2484,20 @@ impl Writeable for OutboundOnionPayload {
 					(6, short_channel_id, required)
 				});
 			},
+			Self::TrampolineEntry {
+				amt_to_forward, outgoing_cltv_value, ref payment_data,
+				ref trampoline_packet
+			} => {
+				_encode_varint_length_prefixed_tlv!(w, {
+					(2, HighZeroBytesDroppedBigSize(*amt_to_forward), required),
+					(4, HighZeroBytesDroppedBigSize(*outgoing_cltv_value), required),
+					(8, payment_data, option),
+					(20, trampoline_packet, required)
+				});
+			},
 			Self::Receive {
 				ref payment_data, ref payment_metadata, ref keysend_preimage, sender_intended_htlc_amt_msat,
-				cltv_expiry_height, ref trampoline_packet, ref custom_tlvs,
+				cltv_expiry_height, ref custom_tlvs,
 			} => {
 				// We need to update [`ln::outbound_payment::RecipientOnionFields::with_custom_tlvs`]
 				// to reject any reserved types in the experimental range if new ones are ever
@@ -2495,8 +2511,7 @@ impl Writeable for OutboundOnionPayload {
 					(2, HighZeroBytesDroppedBigSize(*sender_intended_htlc_amt_msat), required),
 					(4, HighZeroBytesDroppedBigSize(*cltv_expiry_height), required),
 					(8, payment_data, option),
-					(16, payment_metadata.as_ref().map(|m| WithoutLength(m)), option),
-					(20, trampoline_packet, option)
+					(16, payment_metadata.as_ref().map(|m| WithoutLength(m)), option)
 				}, custom_tlvs.iter());
 			},
 			Self::BlindedForward { encrypted_tlvs, intro_node_blinding_point } => {
@@ -4223,7 +4238,6 @@ mod tests {
 			sender_intended_htlc_amt_msat: 0x0badf00d01020304,
 			cltv_expiry_height: 0xffffffff,
 			custom_tlvs: vec![],
-			trampoline_packet: None
 		};
 		let encoded_value = outbound_msg.encode();
 		let target_value = <Vec<u8>>::from_hex("1002080badf00d010203040404ffffffff").unwrap();
@@ -4252,7 +4266,6 @@ mod tests {
 			sender_intended_htlc_amt_msat: 0x0badf00d01020304,
 			cltv_expiry_height: 0xffffffff,
 			custom_tlvs: vec![],
-			trampoline_packet: None
 		};
 		let encoded_value = outbound_msg.encode();
 		let target_value = <Vec<u8>>::from_hex("3602080badf00d010203040404ffffffff082442424242424242424242424242424242424242424242424242424242424242421badca1f").unwrap();
@@ -4292,7 +4305,6 @@ mod tests {
 			custom_tlvs: bad_type_range_tlvs,
 			sender_intended_htlc_amt_msat: 0x0badf00d01020304,
 			cltv_expiry_height: 0xffffffff,
-			trampoline_packet: None
 		};
 		let encoded_value = msg.encode();
 		let node_signer = test_utils::TestKeysInterface::new(&[42; 32], Network::Testnet);
@@ -4325,7 +4337,6 @@ mod tests {
 			custom_tlvs: expected_custom_tlvs.clone(),
 			sender_intended_htlc_amt_msat: 0x0badf00d01020304,
 			cltv_expiry_height: 0xffffffff,
-			trampoline_packet: None
 		};
 		let encoded_value = msg.encode();
 		let target_value = <Vec<u8>>::from_hex("2e02080badf00d010203040404ffffffffff0000000146c6616b021234ff0000000146c6616f084242424242424242").unwrap();
@@ -4364,14 +4375,11 @@ mod tests {
 		let encoded_trampoline_packet = trampoline_packet.encode();
 		assert_eq!(encoded_trampoline_packet.len(), 716);
 
-		let msg = msgs::OutboundOnionPayload::Receive {
+		let msg = msgs::OutboundOnionPayload::TrampolineEntry {
 			payment_data: None,
-			payment_metadata: None,
-			keysend_preimage: None,
-			custom_tlvs: Vec::new(),
-			sender_intended_htlc_amt_msat: 0x0badf00d01020304,
-			cltv_expiry_height: 0xffffffff,
-			trampoline_packet: Some(trampoline_packet),
+			amt_to_forward: 0x0badf00d01020304,
+			outgoing_cltv_value: 0xffffffff,
+			trampoline_packet,
 		};
 		let encoded_payload = msg.encode();
 

lightning/src/ln/onion_utils.rs

@@ -233,7 +233,6 @@ pub(super) fn build_onion_payloads(
 					custom_tlvs: recipient_onion.custom_tlvs.clone(),
 					sender_intended_htlc_amt_msat: value_msat,
 					cltv_expiry_height: cltv,
-					trampoline_packet: None,
 				});
 			}
 		} else {