Parameterize send_probe with Path instead of Vec<RouteHop>

Just-in-time unblinded probing can happen as soon as a BOLT11 invoice is
scanned. The same can't be same for blinded paths, which are provided after a
round trip with the recipient, making JIT probing them less feasible.
Nonetheless, we should support it.

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -2764,10 +2764,10 @@ where
 	/// Send a payment that is probing the given route for liquidity. We calculate the
 	/// [`PaymentHash`] of probes based on a static secret and a random [`PaymentId`], which allows
 	/// us to easily discern them from real payments.
-	pub fn send_probe(&self, hops: Vec<RouteHop>) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
+	pub fn send_probe(&self, path: Path) -> Result<(PaymentHash, PaymentId), PaymentSendFailure> {
 		let best_block_height = self.best_block.read().unwrap().height();
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
-		self.pending_outbound_payments.send_probe(hops, self.probing_cookie_secret, &self.entropy_source, &self.node_signer, best_block_height,
+		self.pending_outbound_payments.send_probe(path, self.probing_cookie_secret, &self.entropy_source, &self.node_signer, best_block_height,
 			|path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv|
 			self.send_payment_along_path(path, payment_hash, payment_secret, total_value, cur_height, payment_id, keysend_preimage, session_priv))
 	}

lightning/src/ln/outbound_payment.rs

@@ -18,7 +18,7 @@ use crate::events;
 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 use crate::ln::channelmanager::{ChannelDetails, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
 use crate::ln::onion_utils::HTLCFailReason;
-use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteHop, RouteParameters, Router};
+use crate::routing::router::{InFlightHtlcs, Path, PaymentParameters, Route, RouteParameters, Router};
 use crate::util::errors::APIError;
 use crate::util::logger::Logger;
 use crate::util::time::Time;
@@ -799,8 +799,8 @@ impl OutboundPayments {
 	}
 
 	pub(super) fn send_probe<ES: Deref, NS: Deref, F>(
-		&self, hops: Vec<RouteHop>, probing_cookie_secret: [u8; 32], entropy_source: &ES,
-		node_signer: &NS, best_block_height: u32, send_payment_along_path: F
+		&self, path: Path, probing_cookie_secret: [u8; 32], entropy_source: &ES, node_signer: &NS,
+		best_block_height: u32, send_payment_along_path: F
 	) -> Result<(PaymentHash, PaymentId), PaymentSendFailure>
 	where
 		ES::Target: EntropySource,
@@ -812,13 +812,13 @@ impl OutboundPayments {
 
 		let payment_hash = probing_cookie_from_id(&payment_id, probing_cookie_secret);
 
-		if hops.len() < 2 {
+		if path.len() < 2 {
 			return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError {
 				err: "No need probing a path with less than two hops".to_string()
 			}))
 		}
 
-		let route = Route { paths: vec![Path { hops, blinded_tail: None }], payment_params: None };
+		let route = Route { paths: vec![path], payment_params: None };
 		let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, None, &route, None, None, entropy_source, best_block_height)?;
 
 		match self.pay_route_internal(&route, payment_hash, &None, None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path) {

lightning/src/ln/payment_tests.rs

@@ -878,12 +878,12 @@ fn sent_probe_is_probe_of_sending_node() {
 
 	// First check we refuse to build a single-hop probe
 	let (route, _, _, _) = get_route_and_payment_hash!(&nodes[0], nodes[1], 100_000);
-	assert!(nodes[0].node.send_probe(route.paths[0].hops.clone()).is_err());
+	assert!(nodes[0].node.send_probe(route.paths[0].clone()).is_err());
 
 	// Then build an actual two-hop probing path
 	let (route, _, _, _) = get_route_and_payment_hash!(&nodes[0], nodes[2], 100_000);
 
-	match nodes[0].node.send_probe(route.paths[0].hops.clone()) {
+	match nodes[0].node.send_probe(route.paths[0].clone()) {
 		Ok((payment_hash, payment_id)) => {
 			assert!(nodes[0].node.payment_is_probe(&payment_hash, &payment_id));
 			assert!(!nodes[1].node.payment_is_probe(&payment_hash, &payment_id));
@@ -908,7 +908,7 @@ fn successful_probe_yields_event() {
 
 	let (route, _, _, _) = get_route_and_payment_hash!(&nodes[0], nodes[2], 100_000);
 
-	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].hops.clone()).unwrap();
+	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].clone()).unwrap();
 
 	// node[0] -- update_add_htlcs -> node[1]
 	check_added_monitors!(nodes[0], 1);
@@ -965,7 +965,7 @@ fn failed_probe_yields_event() {
 
 	let (route, _, _, _) = get_route_and_payment_hash!(&nodes[0], nodes[2], &payment_params, 9_998_000, 42);
 
-	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].hops.clone()).unwrap();
+	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].clone()).unwrap();
 
 	// node[0] -- update_add_htlcs -> node[1]
 	check_added_monitors!(nodes[0], 1);
@@ -1013,7 +1013,7 @@ fn onchain_failed_probe_yields_event() {
 
 	// Send a dust HTLC, which will be treated as if it timed out once the channel hits the chain.
 	let (route, _, _, _) = get_route_and_payment_hash!(&nodes[0], nodes[2], &payment_params, 1_000, 42);
-	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].hops.clone()).unwrap();
+	let (payment_hash, payment_id) = nodes[0].node.send_probe(route.paths[0].clone()).unwrap();
 
 	// node[0] -- update_add_htlcs -> node[1]
 	check_added_monitors!(nodes[0], 1);