Create HTLCDestination enum

Author: jurvis

lightning/src/ln/channel.rs

@@ -46,6 +46,7 @@ use io;
 use prelude::*;
 use core::{cmp,mem,fmt};
 use core::ops::Deref;
+use io::Error;
 #[cfg(any(test, fuzzing, debug_assertions))]
 use sync::Mutex;
 use bitcoin::hashes::hex::ToHex;
@@ -799,6 +800,36 @@ impl fmt::Debug for ChannelError {
 	}
 }
 
+/// Used to return destination of where we are forwarding our HTLC to.
+#[derive(Clone, Debug)]
+pub enum HTLCDestination {
+	OpenChannel { node_id: PublicKey, channel_id: [u8; 32] },
+	Unknown { previous_hop_scid: u64 },
+	Payment { payment_hash: PaymentHash, payment_preimage: Option<PaymentPreimage> },
+}
+
+impl Writeable for HTLCDestination {
+	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), Error> {
+		match self {
+			HTLCDestination::OpenChannel { ref node_id, ref channel_id } => {
+				0u8.write(writer)?;
+				node_id.write(writer)?;
+				channel_id.write(writer)?;
+			},
+			HTLCDestination::Unknown { ref previous_hop_scid } => {
+				1u8.write(writer)?;
+				previous_hop_scid.write(writer)?;
+			},
+			HTLCDestination::Payment { ref payment_hash, ref payment_preimage } => {
+				2u8.write(writer)?;
+				payment_hash.write(writer)?;
+				payment_preimage.write(writer)?;
+			}
+		}
+		Ok(())
+	}
+}
+
 macro_rules! secp_check {
 	($res: expr, $err: expr) => {
 		match $res {

lightning/src/util/events.rs

@@ -16,7 +16,7 @@
 
 use chain::keysinterface::SpendableOutputDescriptor;
 use ln::channelmanager::PaymentId;
-use ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
+use ln::channel::{FUNDING_CONF_DEADLINE_BLOCKS, HTLCDestination};
 use ln::features::ChannelTypeFeatures;
 use ln::msgs;
 use ln::msgs::DecodeError;
@@ -451,9 +451,9 @@ pub enum Event {
 	/// Indicates that a payment has failed to be forwarded through us
 	PaymentForwardedFailed {
 		/// The channel_id of the sender
-		source_channel_id: u64,
-		/// The node_id of the receiver where forwarding has failed
-		sink_node_id: PublicKey
+		source_channel_id: [u8; 32],
+		/// Destination of payment:
+		destination: HTLCDestination
 	},
 }
 
@@ -573,11 +573,11 @@ impl Writeable for Event {
 				// We never write the OpenChannelRequest events as, upon disconnection, peers
 				// drop any channels which have not yet exchanged funding_signed.
 			},
-			&Event::PaymentForwardedFailed { ref source_channel_id, ref sink_node_id } => {
+			&Event::PaymentForwardedFailed { ref source_channel_id, ref destination } => {
 				18u8.write(writer)?;
 				write_tlv_fields!(writer, {
 					(0, source_channel_id, required),
-					(2, sink_node_id, required),
+					(2, destination, required),
 				})
 			}
 			// Note that, going forward, all new events must only write data inside of