Expose more info in PaymentForwarded event

lightning/src/ln/chanmon_update_fail_tests.rs

@@ -1102,7 +1102,7 @@ fn test_monitor_update_fail_reestablish() {
 	assert!(updates.update_fee.is_none());
 	assert_eq!(updates.update_fulfill_htlcs.len(), 1);
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
-	expect_payment_forwarded!(nodes[1], Some(1000), false);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), false);
 	check_added_monitors!(nodes[1], 1);
 	assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
 	commitment_signed_dance!(nodes[1], nodes[2], updates.commitment_signed, false);
@@ -2087,7 +2087,7 @@ fn test_fail_htlc_on_broadcast_after_claim() {
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &cs_updates.update_fulfill_htlcs[0]);
 	let bs_updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 	check_added_monitors!(nodes[1], 1);
-	expect_payment_forwarded!(nodes[1], Some(1000), false);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), false);
 
 	mine_transaction(&nodes[1], &bs_txn[0]);
 	check_closed_event!(nodes[1], 1, ClosureReason::CommitmentTxConfirmed);
@@ -2423,7 +2423,7 @@ fn do_test_reconnect_dup_htlc_claims(htlc_status: HTLCStatusAtDupClaim, second_f
 	let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
 
 	create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
-	let chan_2 = create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known()).2;
+	let chan_id_2 = create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known()).2;
 
 	let (payment_preimage, payment_hash, _) = route_payment(&nodes[0], &[&nodes[1], &nodes[2]], 100_000);
 
@@ -2450,7 +2450,7 @@ fn do_test_reconnect_dup_htlc_claims(htlc_status: HTLCStatusAtDupClaim, second_f
 	}
 
 	let fulfill_msg = msgs::UpdateFulfillHTLC {
-		channel_id: chan_2,
+		channel_id: chan_id_2,
 		htlc_id: 0,
 		payment_preimage,
 	};
@@ -2468,7 +2468,7 @@ fn do_test_reconnect_dup_htlc_claims(htlc_status: HTLCStatusAtDupClaim, second_f
 		assert_eq!(fulfill_msg, cs_updates.update_fulfill_htlcs[0]);
 	}
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &fulfill_msg);
-	expect_payment_forwarded!(nodes[1], Some(1000), false);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), false);
 	check_added_monitors!(nodes[1], 1);
 
 	let mut bs_updates = None;

lightning/src/ln/channelmanager.rs

@@ -4291,7 +4291,10 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 						} else { None };
 
 						let mut pending_events = self.pending_events.lock().unwrap();
+
+						let source_channel_id = Some(prev_outpoint.to_channel_id());
 						pending_events.push(events::Event::PaymentForwarded {
+							source_channel_id,
 							fee_earned_msat,
 							claim_from_onchain_tx: from_onchain,
 						});

lightning/src/ln/functional_test_utils.rs

@@ -1328,12 +1328,16 @@ macro_rules! expect_payment_path_successful {
 }
 
 macro_rules! expect_payment_forwarded {
-	($node: expr, $expected_fee: expr, $upstream_force_closed: expr) => {
+	($node: expr, $source_node: expr, $expected_fee: expr, $upstream_force_closed: expr) => {
 		let events = $node.node.get_and_clear_pending_events();
 		assert_eq!(events.len(), 1);
 		match events[0] {
-			Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
+			Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
 				assert_eq!(fee_earned_msat, $expected_fee);
+				if fee_earned_msat.is_some() {
+					// Is the event channel_id in one of the channels between the two nodes?
+					assert!($node.node.list_channels().iter().any(|x| x.counterparty.node_id == $source_node.node.get_our_node_id() && x.channel_id == source_channel_id.unwrap()));
+				}
 				assert_eq!(claim_from_onchain_tx, $upstream_force_closed);
 			},
 			_ => panic!("Unexpected event"),
@@ -1572,11 +1576,11 @@ pub fn do_claim_payment_along_route<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>,
 			}
 		}
 		macro_rules! mid_update_fulfill_dance {
-			($node: expr, $prev_node: expr, $new_msgs: expr) => {
+			($node: expr, $prev_node: expr, $next_node: expr, $new_msgs: expr) => {
 				{
 					$node.node.handle_update_fulfill_htlc(&$prev_node.node.get_our_node_id(), &next_msgs.as_ref().unwrap().0);
 					let fee = $node.node.channel_state.lock().unwrap().by_id.get(&next_msgs.as_ref().unwrap().0.channel_id).unwrap().config.forwarding_fee_base_msat;
-					expect_payment_forwarded!($node, Some(fee as u64), false);
+					expect_payment_forwarded!($node, $next_node, Some(fee as u64), false);
 					expected_total_fee_msat += fee as u64;
 					check_added_monitors!($node, 1);
 					let new_next_msgs = if $new_msgs {
@@ -1600,7 +1604,14 @@ pub fn do_claim_payment_along_route<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>,
 			assert_eq!(expected_next_node, node.node.get_our_node_id());
 			let update_next_msgs = !skip_last || idx != expected_route.len() - 1;
 			if next_msgs.is_some() {
-				mid_update_fulfill_dance!(node, prev_node, update_next_msgs);
+				// Since we are traversing in reverse, next_node is actually the previous node
+				let next_node: &Node;
+				if idx == expected_route.len() - 1 {
+					next_node = origin_node;
+				} else {
+					next_node = expected_route[expected_route.len() - 1 - idx - 1];
+				}
+				mid_update_fulfill_dance!(node, prev_node, next_node, update_next_msgs);
 			} else {
 				assert!(!update_next_msgs);
 				assert!(node.node.get_and_clear_pending_msg_events().is_empty());

lightning/src/ln/functional_tests.rs

@@ -2684,10 +2684,23 @@ fn test_htlc_on_chain_success() {
 		Event::ChannelClosed { reason: ClosureReason::CommitmentTxConfirmed, .. } => {}
 		_ => panic!("Unexpected event"),
 	}
-	if let Event::PaymentForwarded { fee_earned_msat: Some(1000), claim_from_onchain_tx: true } = forwarded_events[1] {
-		} else { panic!(); }
-	if let Event::PaymentForwarded { fee_earned_msat: Some(1000), claim_from_onchain_tx: true } = forwarded_events[2] {
-		} else { panic!(); }
+	let chan_id = Some(chan_1.2);
+	match forwarded_events[1] {
+		Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
+			assert_eq!(fee_earned_msat, Some(1000));
+			assert_eq!(source_channel_id, chan_id);
+			assert_eq!(claim_from_onchain_tx, true);
+		},
+		_ => panic!()
+	}
+	match forwarded_events[2] {
+		Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
+			assert_eq!(fee_earned_msat, Some(1000));
+			assert_eq!(source_channel_id, chan_id);
+			assert_eq!(claim_from_onchain_tx, true);
+		},
+		_ => panic!()
+	}
 	let events = nodes[1].node.get_and_clear_pending_msg_events();
 	{
 		let mut added_monitors = nodes[1].chain_monitor.added_monitors.lock().unwrap();
@@ -5104,8 +5117,9 @@ fn test_onchain_to_onchain_claim() {
 		_ => panic!("Unexpected event"),
 	}
 	match events[1] {
-		Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
+		Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
 			assert_eq!(fee_earned_msat, Some(1000));
+			assert_eq!(source_channel_id, Some(chan_1.2));
 			assert_eq!(claim_from_onchain_tx, true);
 		},
 		_ => panic!("Unexpected event"),
@@ -5271,7 +5285,7 @@ fn test_duplicate_payment_hash_one_failure_one_success() {
 	// Note that the fee paid is effectively double as the HTLC value (including the nodes[1] fee
 	// and nodes[2] fee) is rounded down and then claimed in full.
 	mine_transaction(&nodes[1], &htlc_success_txn[0]);
-	expect_payment_forwarded!(nodes[1], Some(196*2), true);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(196*2), true);
 	let updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 	assert!(updates.update_add_htlcs.is_empty());
 	assert!(updates.update_fail_htlcs.is_empty());
@@ -8849,7 +8863,7 @@ fn do_test_onchain_htlc_settlement_after_close(broadcast_alice: bool, go_onchain
 	assert_eq!(carol_updates.update_fulfill_htlcs.len(), 1);
 
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &carol_updates.update_fulfill_htlcs[0]);
-	expect_payment_forwarded!(nodes[1], if go_onchain_before_fulfill || force_closing_node == 1 { None } else { Some(1000) }, false);
+	expect_payment_forwarded!(nodes[1], nodes[0], if go_onchain_before_fulfill || force_closing_node == 1 { None } else { Some(1000) }, false);
 	// If Alice broadcasted but Bob doesn't know yet, here he prepares to tell her about the preimage.
 	if !go_onchain_before_fulfill && broadcast_alice {
 		let events = nodes[1].node.get_and_clear_pending_msg_events();

lightning/src/ln/payment_tests.rs

@@ -495,7 +495,7 @@ fn do_retry_with_no_persist(confirm_before_reload: bool) {
 	let bs_htlc_claim_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0);
 	assert_eq!(bs_htlc_claim_txn.len(), 1);
 	check_spends!(bs_htlc_claim_txn[0], as_commitment_tx);
-	expect_payment_forwarded!(nodes[1], None, false);
+	expect_payment_forwarded!(nodes[1], nodes[0], None, false);
 
 	if !confirm_before_reload {
 		mine_transaction(&nodes[0], &as_commitment_tx);

lightning/src/ln/reorg_tests.rs

@@ -138,7 +138,7 @@ fn do_test_onchain_htlc_reorg(local_commitment: bool, claim: bool) {
 		// ChannelManager only polls chain::Watch::release_pending_monitor_events when we
 		// probe it for events, so we probe non-message events here (which should just be the
 		// PaymentForwarded event).
-		expect_payment_forwarded!(nodes[1], Some(1000), true);
+		expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), true);
 	} else {
 		// Confirm the timeout tx and check that we fail the HTLC backwards
 		let block = Block {

lightning/src/ln/shutdown_tests.rs

@@ -110,7 +110,7 @@ fn updates_shutdown_wait() {
 	assert!(updates.update_fee.is_none());
 	assert_eq!(updates.update_fulfill_htlcs.len(), 1);
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
-	expect_payment_forwarded!(nodes[1], Some(1000), false);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), false);
 	check_added_monitors!(nodes[1], 1);
 	let updates_2 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 	commitment_signed_dance!(nodes[1], nodes[2], updates.commitment_signed, false);
@@ -279,7 +279,7 @@ fn do_test_shutdown_rebroadcast(recv_count: u8) {
 	assert!(updates.update_fee.is_none());
 	assert_eq!(updates.update_fulfill_htlcs.len(), 1);
 	nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &updates.update_fulfill_htlcs[0]);
-	expect_payment_forwarded!(nodes[1], Some(1000), false);
+	expect_payment_forwarded!(nodes[1], nodes[0], Some(1000), false);
 	check_added_monitors!(nodes[1], 1);
 	let updates_2 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 	commitment_signed_dance!(nodes[1], nodes[2], updates.commitment_signed, false);

lightning/src/util/events.rs

@@ -343,6 +343,9 @@ pub enum Event {
 	/// This event is generated when a payment has been successfully forwarded through us and a
 	/// forwarding fee earned.
 	PaymentForwarded {
+		/// The channel between the source node and us. Optional because versions prior to 0.0.107
+		/// do not serialize this field.
+		source_channel_id: Option<[u8; 32]>,
 		/// The fee, in milli-satoshis, which was earned as a result of the payment.
 		///
 		/// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
@@ -520,10 +523,11 @@ impl Writeable for Event {
 					(0, VecWriteWrapper(outputs), required),
 				});
 			},
-			&Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
+			&Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
 				7u8.write(writer)?;
 				write_tlv_fields!(writer, {
 					(0, fee_earned_msat, option),
+					(1, source_channel_id, option),
 					(2, claim_from_onchain_tx, required),
 				});
 			},
@@ -684,12 +688,14 @@ impl MaybeReadable for Event {
 			7u8 => {
 				let f = || {
 					let mut fee_earned_msat = None;
+					let mut source_channel_id = None;
 					let mut claim_from_onchain_tx = false;
 					read_tlv_fields!(reader, {
 						(0, fee_earned_msat, option),
+						(1, source_channel_id, option),
 						(2, claim_from_onchain_tx, required),
 					});
-					Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
+					Ok(Some(Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx }))
 				};
 				f()
 			},