Expose the RecipientOnionFields in Event::PaymentClaimable

This finally completes the piping of the `payment_metadata` from
from the BOLT11 invoice on the sending side all the way through the
onion sending + receiving ends to the user on the receive events.

Author: TheBlueMatt

lightning/src/events/mod.rs

@@ -21,7 +21,7 @@ pub mod bump_transaction;
 pub use bump_transaction::BumpTransactionEvent;
 
 use crate::chain::keysinterface::SpendableOutputDescriptor;
-use crate::ln::channelmanager::{InterceptId, PaymentId};
+use crate::ln::channelmanager::{InterceptId, PaymentId, RecipientOnionFields};
 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
 use crate::ln::features::ChannelTypeFeatures;
 use crate::ln::msgs;
@@ -342,6 +342,11 @@ pub enum Event {
 		/// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
 		/// not stop you from registering duplicate payment hashes for inbound payments.
 		payment_hash: PaymentHash,
+		/// The fields in the onion which were received with each HTLC. Only fields which were
+		/// identical in each HTLC involved in the payment will be included here.
+		///
+		/// Payments received on LDK versions prior to 0.0.115 will have this field unset.
+		onion_fields: Option<RecipientOnionFields>,
 		/// The value, in thousandths of a satoshi, that this payment is for.
 		amount_msat: u64,
 		/// Information for claiming this received payment, based on whether the purpose of the
@@ -780,7 +785,10 @@ impl Writeable for Event {
 				// We never write out FundingGenerationReady events as, upon disconnection, peers
 				// drop any channels which have not yet exchanged funding_signed.
 			},
-			&Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id, ref claim_deadline } => {
+			&Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose,
+				ref receiver_node_id, ref via_channel_id, ref via_user_channel_id,
+				ref claim_deadline, ref onion_fields
+			} => {
 				1u8.write(writer)?;
 				let mut payment_secret = None;
 				let payment_preimage;
@@ -803,6 +811,7 @@ impl Writeable for Event {
 					(6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
 					(7, claim_deadline, option),
 					(8, payment_preimage, option),
+					(9, onion_fields, option),
 				});
 			},
 			&Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
@@ -1002,6 +1011,7 @@ impl MaybeReadable for Event {
 					let mut via_channel_id = None;
 					let mut claim_deadline = None;
 					let mut via_user_channel_id = None;
+					let mut onion_fields = None;
 					read_tlv_fields!(reader, {
 						(0, payment_hash, required),
 						(1, receiver_node_id, option),
@@ -1012,6 +1022,7 @@ impl MaybeReadable for Event {
 						(6, _user_payment_id, option),
 						(7, claim_deadline, option),
 						(8, payment_preimage, option),
+						(9, onion_fields, option),
 					});
 					let purpose = match payment_secret {
 						Some(secret) => PaymentPurpose::InvoicePayment {
@@ -1029,6 +1040,7 @@ impl MaybeReadable for Event {
 						via_channel_id,
 						via_user_channel_id,
 						claim_deadline,
+						onion_fields,
 					}))
 				};
 				f()

lightning/src/ln/channelmanager.rs

@@ -3432,6 +3432,7 @@ where
 												via_channel_id: Some(prev_channel_id),
 												via_user_channel_id: Some(prev_user_channel_id),
 												claim_deadline: Some(earliest_expiry - HTLC_FAIL_BACK_BUFFER),
+												onion_fields: claimable_payment.onion_fields.clone(),
 											});
 											payment_claimable_generated = true;
 										} else {
@@ -3501,6 +3502,7 @@ where
 															via_channel_id: Some(prev_channel_id),
 															via_user_channel_id: Some(prev_user_channel_id),
 															claim_deadline,
+															onion_fields: Some(onion_fields),
 														});
 													},
 													hash_map::Entry::Occupied(_) => {

lightning/src/ln/functional_test_utils.rs

@@ -1981,21 +1981,26 @@ pub fn do_pass_along_path<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, expected_p
 			let events_2 = node.node.get_and_clear_pending_events();
 			if payment_claimable_expected {
 				assert_eq!(events_2.len(), 1);
-				match events_2[0] {
-					Event::PaymentClaimable { ref payment_hash, ref purpose, amount_msat, receiver_node_id, ref via_channel_id, ref via_user_channel_id, claim_deadline } => {
+				match &events_2[0] {
+					Event::PaymentClaimable { ref payment_hash, ref purpose, amount_msat,
+						receiver_node_id, ref via_channel_id, ref via_user_channel_id,
+						claim_deadline, onion_fields,
+					} => {
 						assert_eq!(our_payment_hash, *payment_hash);
 						assert_eq!(node.node.get_our_node_id(), receiver_node_id.unwrap());
+						assert!(onion_fields.is_some());
 						match &purpose {
 							PaymentPurpose::InvoicePayment { payment_preimage, payment_secret, .. } => {
 								assert_eq!(expected_preimage, *payment_preimage);
 								assert_eq!(our_payment_secret.unwrap(), *payment_secret);
+								assert_eq!(Some(*payment_secret), onion_fields.as_ref().unwrap().payment_secret);
 							},
 							PaymentPurpose::SpontaneousPayment(payment_preimage) => {
 								assert_eq!(expected_preimage.unwrap(), *payment_preimage);
 								assert!(our_payment_secret.is_none());
 							},
 						}
-						assert_eq!(amount_msat, recv_value);
+						assert_eq!(*amount_msat, recv_value);
 						assert!(node.node.list_channels().iter().any(|details| details.channel_id == via_channel_id.unwrap()));
 						assert!(node.node.list_channels().iter().any(|details| details.user_channel_id == via_user_channel_id.unwrap()));
 						assert!(claim_deadline.unwrap() > node.best_block_info().1);

lightning/src/ln/outbound_payment.rs

@@ -409,7 +409,7 @@ pub enum PaymentSendFailure {
 ///
 /// This should generally be constructed with data communicated to us from the recipient (via a
 /// BOLT11 or BOLT12 invoice).
-#[derive(Clone)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct RecipientOnionFields {
 	/// The [`PaymentSecret`] is an arbitrary 32 bytes provided by the recipient for us to repeat
 	/// in the onion. It is unrelated to `payment_hash` (or [`PaymentPreimage`]) and exists to