X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Fblinded_path%2Fmessage.rs;h=967ef612c318ad189ee93e0cb9c1b2dc63b8a529;hb=d85e0d619a5225cbf73bdf7cac7f400529cb6a73;hp=bdcbd7726f71189175407bc3dd125aad2c1db199;hpb=eaf76f6cceefdc08202d7fe08e4760df0e824d38;p=rust-lightning

diff --git a/lightning/src/blinded_path/message.rs b/lightning/src/blinded_path/message.rs
index bdcbd772..967ef612 100644
--- a/lightning/src/blinded_path/message.rs
+++ b/lightning/src/blinded_path/message.rs
@@ -19,8 +19,8 @@ use core::ops::Deref;
 /// TLVs to encode in an intermediate onion message packet's hop data. When provided in a blinded
 /// route, they are encoded into [`BlindedHop::encrypted_payload`].
 pub(crate) struct ForwardTlvs {
-	/// The node id of the next hop in the onion message's path.
-	pub(crate) next_node_id: PublicKey,
+	/// The next hop in the onion message's path.
+	pub(crate) next_hop: NextHop,
 	/// Senders to a blinded path use this value to concatenate the route they find to the
 	/// introduction node with the blinded path.
 	pub(crate) next_blinding_override: Option<PublicKey>,
@@ -34,11 +34,25 @@ pub(crate) struct ReceiveTlvs {
 	pub(crate) path_id: Option<[u8; 32]>,
 }
 
+/// The next hop to forward the onion message along its path.
+#[derive(Debug)]
+pub enum NextHop {
+	/// The node id of the next hop.
+	NodeId(PublicKey),
+	/// The short channel id leading to the next hop.
+	ShortChannelId(u64),
+}
+
 impl Writeable for ForwardTlvs {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
+		let (next_node_id, short_channel_id) = match self.next_hop {
+			NextHop::NodeId(pubkey) => (Some(pubkey), None),
+			NextHop::ShortChannelId(scid) => (None, Some(scid)),
+		};
 		// TODO: write padding
 		encode_tlv_stream!(writer, {
-			(4, self.next_node_id, required),
+			(2, short_channel_id, option),
+			(4, next_node_id, option),
 			(8, self.next_blinding_override, option)
 		});
 		Ok(())
@@ -61,9 +75,8 @@ pub(super) fn blinded_hops<T: secp256k1::Signing + secp256k1::Verification>(
 ) -> Result<Vec<BlindedHop>, secp256k1::Error> {
 	let blinded_tlvs = unblinded_path.iter()
 		.skip(1) // The first node's TLVs contains the next node's pubkey
-		.map(|pk| {
-			ControlTlvs::Forward(ForwardTlvs { next_node_id: *pk, next_blinding_override: None })
-		})
+		.map(|pk| ForwardTlvs { next_hop: NextHop::NodeId(*pk), next_blinding_override: None })
+		.map(|tlvs| ControlTlvs::Forward(tlvs))
 		.chain(core::iter::once(ControlTlvs::Receive(ReceiveTlvs { path_id: None })));
 
 	utils::construct_blinded_hops(secp_ctx, unblinded_path.iter(), blinded_tlvs, session_priv)
@@ -80,9 +93,13 @@ pub(crate) fn advance_path_by_one<NS: Deref, T: secp256k1::Signing + secp256k1::
 	let mut s = Cursor::new(&encrypted_control_tlvs);
 	let mut reader = FixedLengthReader::new(&mut s, encrypted_control_tlvs.len() as u64);
 	match ChaChaPolyReadAdapter::read(&mut reader, rho) {
-		Ok(ChaChaPolyReadAdapter { readable: ControlTlvs::Forward(ForwardTlvs {
-			mut next_node_id, next_blinding_override,
-		})}) => {
+		Ok(ChaChaPolyReadAdapter {
+			readable: ControlTlvs::Forward(ForwardTlvs { next_hop, next_blinding_override })
+		}) => {
+			let mut next_node_id = match next_hop {
+				NextHop::NodeId(pubkey) => pubkey,
+				NextHop::ShortChannelId(_) => todo!(),
+			};
 			let mut new_blinding_point = match next_blinding_override {
 				Some(blinding_point) => blinding_point,
 				None => {