X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning-invoice%2Fsrc%2Fpayment.rs;h=476d12a34751e885c43980453ede2db9288d0cd5;hb=refs%2Fheads%2F2022-07-warnings;hp=46bd86fb03ccef3a2169e37afe5558c27cc11afa;hpb=a3e4af0bb800a7fbc9d7908a41706d211eeda835;p=rust-lightning

diff --git a/lightning-invoice/src/payment.rs b/lightning-invoice/src/payment.rs
index 46bd86fb..476d12a3 100644
--- a/lightning-invoice/src/payment.rs
+++ b/lightning-invoice/src/payment.rs
@@ -15,6 +15,10 @@
 //! and payee using information provided by the payer and from the payee's [`Invoice`], when
 //! applicable.
 //!
+//! [`InvoicePayer`] is parameterized by a [`LockableScore`], which it uses for scoring failed and
+//! successful payment paths upon receiving [`Event::PaymentPathFailed`] and
+//! [`Event::PaymentPathSuccessful`] events, respectively.
+//!
 //! [`InvoicePayer`] is capable of retrying failed payments. It accomplishes this by implementing
 //! [`EventHandler`] which decorates a user-provided handler. It will intercept any
 //! [`Event::PaymentPathFailed`] events and retry the failed paths for a fixed number of total
@@ -28,21 +32,29 @@
 //! # extern crate lightning_invoice;
 //! # extern crate secp256k1;
 //! #
+//! # #[cfg(feature = "no-std")]
+//! # extern crate core2;
+//! #
 //! # use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 //! # use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
 //! # use lightning::ln::msgs::LightningError;
-//! # use lightning::routing::scoring::Score;
-//! # use lightning::routing::network_graph::NodeId;
+//! # use lightning::routing::gossip::NodeId;
 //! # use lightning::routing::router::{Route, RouteHop, RouteParameters};
+//! # use lightning::routing::scoring::{ChannelUsage, Score};
 //! # use lightning::util::events::{Event, EventHandler, EventsProvider};
 //! # use lightning::util::logger::{Logger, Record};
 //! # use lightning::util::ser::{Writeable, Writer};
 //! # use lightning_invoice::Invoice;
-//! # use lightning_invoice::payment::{InvoicePayer, Payer, RetryAttempts, Router};
-//! # use secp256k1::key::PublicKey;
+//! # use lightning_invoice::payment::{InvoicePayer, Payer, Retry, Router};
+//! # use secp256k1::PublicKey;
 //! # use std::cell::RefCell;
 //! # use std::ops::Deref;
 //! #
+//! # #[cfg(not(feature = "std"))]
+//! # use core2::io;
+//! # #[cfg(feature = "std")]
+//! # use std::io;
+//! #
 //! # struct FakeEventProvider {}
 //! # impl EventsProvider for FakeEventProvider {
 //! #     fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler {}
@@ -61,6 +73,7 @@
 //! #     fn retry_payment(
 //! #         &self, route: &Route, payment_id: PaymentId
 //! #     ) -> Result<(), PaymentSendFailure> { unimplemented!() }
+//! #     fn abandon_payment(&self, payment_id: PaymentId) { unimplemented!() }
 //! # }
 //! #
 //! # struct FakeRouter {}
@@ -73,13 +86,16 @@
 //! #
 //! # struct FakeScorer {}
 //! # impl Writeable for FakeScorer {
-//! #     fn write<W: Writer>(&self, w: &mut W) -> Result<(), std::io::Error> { unimplemented!(); }
+//! #     fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> { unimplemented!(); }
 //! # }
 //! # impl Score for FakeScorer {
 //! #     fn channel_penalty_msat(
-//! #         &self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId
+//! #         &self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId, _usage: ChannelUsage
 //! #     ) -> u64 { 0 }
 //! #     fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+//! #     fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
+//! #     fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+//! #     fn probe_successful(&mut self, _path: &[&RouteHop]) {}
 //! # }
 //! #
 //! # struct FakeLogger {}
@@ -99,7 +115,7 @@
 //! # let router = FakeRouter {};
 //! # let scorer = RefCell::new(FakeScorer {});
 //! # let logger = FakeLogger {};
-//! let invoice_payer = InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+//! let invoice_payer = InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 //!
 //! let invoice = "...";
 //! if let Ok(invoice) = invoice.parse::<Invoice>() {
@@ -124,29 +140,47 @@ use crate::Invoice;
 use bitcoin_hashes::Hash;
 use bitcoin_hashes::sha256::Hash as Sha256;
 
+use crate::prelude::*;
 use lightning::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 use lightning::ln::channelmanager::{ChannelDetails, PaymentId, PaymentSendFailure};
 use lightning::ln::msgs::LightningError;
 use lightning::routing::scoring::{LockableScore, Score};
-use lightning::routing::router::{Payee, Route, RouteParameters};
+use lightning::routing::router::{PaymentParameters, Route, RouteParameters};
 use lightning::util::events::{Event, EventHandler};
 use lightning::util::logger::Logger;
+use time_utils::Time;
+use crate::sync::Mutex;
 
-use secp256k1::key::PublicKey;
+use secp256k1::PublicKey;
 
-use std::collections::hash_map::{self, HashMap};
-use std::ops::Deref;
-use std::sync::Mutex;
-use std::time::{Duration, SystemTime};
+use core::fmt;
+use core::fmt::{Debug, Display, Formatter};
+use core::ops::Deref;
+use core::time::Duration;
+#[cfg(feature = "std")]
+use std::time::SystemTime;
 
 /// A utility for paying [`Invoice`]s and sending spontaneous payments.
-pub struct InvoicePayer<P: Deref, R, S: Deref, L: Deref, E>
+///
+/// See [module-level documentation] for details.
+///
+/// [module-level documentation]: crate::payment
+pub type InvoicePayer<P, R, S, L, E> = InvoicePayerUsingTime::<P, R, S, L, E, ConfiguredTime>;
+
+#[cfg(not(feature = "no-std"))]
+type ConfiguredTime = std::time::Instant;
+#[cfg(feature = "no-std")]
+use time_utils;
+#[cfg(feature = "no-std")]
+type ConfiguredTime = time_utils::Eternity;
+
+/// (C-not exported) generally all users should use the [`InvoicePayer`] type alias.
+pub struct InvoicePayerUsingTime<P: Deref, R, S: Deref, L: Deref, E: EventHandler, T: Time>
 where
 	P::Target: Payer,
 	R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
 	S::Target: for <'a> LockableScore<'a>,
 	L::Target: Logger,
-	E: EventHandler,
 {
 	payer: P,
 	router: R,
@@ -154,8 +188,42 @@ where
 	logger: L,
 	event_handler: E,
 	/// Caches the overall attempts at making a payment, which is updated prior to retrying.
-	payment_cache: Mutex<HashMap<PaymentHash, usize>>,
-	retry_attempts: RetryAttempts,
+	payment_cache: Mutex<HashMap<PaymentHash, PaymentAttempts<T>>>,
+	retry: Retry,
+}
+
+/// Storing minimal payment attempts information required for determining if a outbound payment can
+/// be retried.
+#[derive(Clone, Copy)]
+struct PaymentAttempts<T: Time> {
+	/// This count will be incremented only after the result of the attempt is known. When it's 0,
+	/// it means the result of the first attempt is now known yet.
+	count: usize,
+	/// This field is only used when retry is [`Retry::Timeout`] which is only build with feature std
+	first_attempted_at: T
+}
+
+impl<T: Time> PaymentAttempts<T> {
+	fn new() -> Self {
+		PaymentAttempts {
+			count: 0,
+			first_attempted_at: T::now()
+		}
+	}
+}
+
+impl<T: Time> Display for PaymentAttempts<T> {
+	fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
+		#[cfg(feature = "no-std")]
+		return write!( f, "attempts: {}", self.count);
+		#[cfg(not(feature = "no-std"))]
+		return write!(
+			f,
+			"attempts: {}, duration: {}s",
+			self.count,
+			T::now().duration_since(self.first_attempted_at).as_secs()
+		);
+	}
 }
 
 /// A trait defining behavior of an [`Invoice`] payer.
@@ -178,24 +246,47 @@ pub trait Payer {
 
 	/// Retries a failed payment path for the [`PaymentId`] using the given [`Route`].
 	fn retry_payment(&self, route: &Route, payment_id: PaymentId) -> Result<(), PaymentSendFailure>;
+
+	/// Signals that no further retries for the given payment will occur.
+	fn abandon_payment(&self, payment_id: PaymentId);
 }
 
 /// A trait defining behavior for routing an [`Invoice`] payment.
 pub trait Router<S: Score> {
 	/// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
 	fn find_route(
-		&self, payer: &PublicKey, params: &RouteParameters, payment_hash: &PaymentHash,
+		&self, payer: &PublicKey, route_params: &RouteParameters, payment_hash: &PaymentHash,
 		first_hops: Option<&[&ChannelDetails]>, scorer: &S
 	) -> Result<Route, LightningError>;
 }
 
-/// Number of attempts to retry payment path failures for an [`Invoice`].
+/// Strategies available to retry payment path failures for an [`Invoice`].
 ///
-/// Note that this is the number of *path* failures, not full payment retries. For multi-path
-/// payments, if this is less than the total number of paths, we will never even retry all of the
-/// payment's paths.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
-pub struct RetryAttempts(pub usize);
+pub enum Retry {
+	/// Max number of attempts to retry payment.
+	///
+	/// Note that this is the number of *path* failures, not full payment retries. For multi-path
+	/// payments, if this is less than the total number of paths, we will never even retry all of the
+	/// payment's paths.
+	Attempts(usize),
+	#[cfg(feature = "std")]
+	/// Time elapsed before abandoning retries for a payment.
+	Timeout(Duration),
+}
+
+impl Retry {
+	fn is_retryable_now<T: Time>(&self, attempts: &PaymentAttempts<T>) -> bool {
+		match (self, attempts) {
+			(Retry::Attempts(max_retry_count), PaymentAttempts { count, .. }) => {
+				max_retry_count >= &count
+			},
+			#[cfg(feature = "std")]
+			(Retry::Timeout(max_duration), PaymentAttempts { first_attempted_at, .. } ) =>
+				*max_duration >= T::now().duration_since(*first_attempted_at),
+		}
+	}
+}
 
 /// An error that may occur when making a payment.
 #[derive(Clone, Debug)]
@@ -208,20 +299,19 @@ pub enum PaymentError {
 	Sending(PaymentSendFailure),
 }
 
-impl<P: Deref, R, S: Deref, L: Deref, E> InvoicePayer<P, R, S, L, E>
+impl<P: Deref, R, S: Deref, L: Deref, E: EventHandler, T: Time> InvoicePayerUsingTime<P, R, S, L, E, T>
 where
 	P::Target: Payer,
 	R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
 	S::Target: for <'a> LockableScore<'a>,
 	L::Target: Logger,
-	E: EventHandler,
 {
 	/// Creates an invoice payer that retries failed payment paths.
 	///
 	/// Will forward any [`Event::PaymentPathFailed`] events to the decorated `event_handler` once
-	/// `retry_attempts` has been exceeded for a given [`Invoice`].
+	/// `retry` has been exceeded for a given [`Invoice`].
 	pub fn new(
-		payer: P, router: R, scorer: S, logger: L, event_handler: E, retry_attempts: RetryAttempts
+		payer: P, router: R, scorer: S, logger: L, event_handler: E, retry: Retry
 	) -> Self {
 		Self {
 			payer,
@@ -230,7 +320,7 @@ where
 			logger,
 			event_handler,
 			payment_cache: Mutex::new(HashMap::new()),
-			retry_attempts,
+			retry,
 		}
 	}
 
@@ -271,18 +361,18 @@ where
 		let payment_hash = PaymentHash(invoice.payment_hash().clone().into_inner());
 		match self.payment_cache.lock().unwrap().entry(payment_hash) {
 			hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
-			hash_map::Entry::Vacant(entry) => entry.insert(0),
+			hash_map::Entry::Vacant(entry) => entry.insert(PaymentAttempts::new()),
 		};
 
 		let payment_secret = Some(invoice.payment_secret().clone());
-		let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key())
+		let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
 			.with_expiry_time(expiry_time_from_unix_epoch(&invoice).as_secs())
 			.with_route_hints(invoice.route_hints());
 		if let Some(features) = invoice.features() {
-			payee = payee.with_features(features.clone());
+			payment_params = payment_params.with_features(features.clone());
 		}
-		let params = RouteParameters {
-			payee,
+		let route_params = RouteParameters {
+			payment_params,
 			final_value_msat: invoice.amount_milli_satoshis().or(amount_msats).unwrap(),
 			final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
 		};
@@ -290,7 +380,8 @@ where
 		let send_payment = |route: &Route| {
 			self.payer.send_payment(route, payment_hash, &payment_secret)
 		};
-		self.pay_internal(&params, payment_hash, send_payment)
+
+		self.pay_internal(&route_params, payment_hash, send_payment)
 			.map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
 	}
 
@@ -306,11 +397,11 @@ where
 		let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 		match self.payment_cache.lock().unwrap().entry(payment_hash) {
 			hash_map::Entry::Occupied(_) => return Err(PaymentError::Invoice("payment pending")),
-			hash_map::Entry::Vacant(entry) => entry.insert(0),
+			hash_map::Entry::Vacant(entry) => entry.insert(PaymentAttempts::new()),
 		};
 
-		let params = RouteParameters {
-			payee: Payee::for_keysend(pubkey),
+		let route_params = RouteParameters {
+			payment_params: PaymentParameters::for_keysend(pubkey),
 			final_value_msat: amount_msats,
 			final_cltv_expiry_delta,
 		};
@@ -318,16 +409,18 @@ where
 		let send_payment = |route: &Route| {
 			self.payer.send_spontaneous_payment(route, payment_preimage)
 		};
-		self.pay_internal(&params, payment_hash, send_payment)
+		self.pay_internal(&route_params, payment_hash, send_payment)
 			.map_err(|e| { self.payment_cache.lock().unwrap().remove(&payment_hash); e })
 	}
 
 	fn pay_internal<F: FnOnce(&Route) -> Result<PaymentId, PaymentSendFailure> + Copy>(
 		&self, params: &RouteParameters, payment_hash: PaymentHash, send_payment: F,
 	) -> Result<PaymentId, PaymentError> {
-		if has_expired(params) {
-			log_trace!(self.logger, "Invoice expired prior to send for payment {}", log_bytes!(payment_hash.0));
-			return Err(PaymentError::Invoice("Invoice expired prior to send"));
+		#[cfg(feature = "std")] {
+			if has_expired(params) {
+				log_trace!(self.logger, "Invoice expired prior to send for payment {}", log_bytes!(payment_hash.0));
+				return Err(PaymentError::Invoice("Invoice expired prior to send"));
+			}
 		}
 
 		let payer = self.payer.node_id();
@@ -344,13 +437,13 @@ where
 				PaymentSendFailure::PathParameterError(_) => Err(e),
 				PaymentSendFailure::AllFailedRetrySafe(_) => {
 					let mut payment_cache = self.payment_cache.lock().unwrap();
-					let retry_count = payment_cache.get_mut(&payment_hash).unwrap();
-					if *retry_count >= self.retry_attempts.0 {
-						Err(e)
-					} else {
-						*retry_count += 1;
-						std::mem::drop(payment_cache);
+					let payment_attempts = payment_cache.get_mut(&payment_hash).unwrap();
+					payment_attempts.count += 1;
+					if self.retry.is_retryable_now(payment_attempts) {
+						core::mem::drop(payment_cache);
 						Ok(self.pay_internal(params, payment_hash, send_payment)?)
+					} else {
+						Err(e)
 					}
 				},
 				PaymentSendFailure::PartialFailure { failed_paths_retry, payment_id, .. } => {
@@ -376,20 +469,24 @@ where
 	fn retry_payment(
 		&self, payment_id: PaymentId, payment_hash: PaymentHash, params: &RouteParameters
 	) -> Result<(), ()> {
-		let max_payment_attempts = self.retry_attempts.0 + 1;
-		let attempts = *self.payment_cache.lock().unwrap()
-			.entry(payment_hash)
-			.and_modify(|attempts| *attempts += 1)
-			.or_insert(1);
-
-		if attempts >= max_payment_attempts {
-			log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
+		let attempts =
+			*self.payment_cache.lock().unwrap().entry(payment_hash)
+			.and_modify(|attempts| attempts.count += 1)
+			.or_insert(PaymentAttempts {
+				count: 1,
+				first_attempted_at: T::now()
+			});
+
+		if !self.retry.is_retryable_now(&attempts) {
+			log_trace!(self.logger, "Payment {} exceeded maximum attempts; not retrying ({})", log_bytes!(payment_hash.0), attempts);
 			return Err(());
 		}
 
-		if has_expired(params) {
-			log_trace!(self.logger, "Invoice expired for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
-			return Err(());
+		#[cfg(feature = "std")] {
+			if has_expired(params) {
+				log_trace!(self.logger, "Invoice expired for payment {}; not retrying ({:})", log_bytes!(payment_hash.0), attempts);
+				return Err(());
+			}
 		}
 
 		let payer = self.payer.node_id();
@@ -399,7 +496,7 @@ where
 			&self.scorer.lock()
 		);
 		if route.is_err() {
-			log_trace!(self.logger, "Failed to find a route for payment {}; not retrying (attempts: {})", log_bytes!(payment_hash.0), attempts);
+			log_trace!(self.logger, "Failed to find a route for payment {}; not retrying ({:})", log_bytes!(payment_hash.0), attempts);
 			return Err(());
 		}
 
@@ -433,54 +530,74 @@ where
 }
 
 fn expiry_time_from_unix_epoch(invoice: &Invoice) -> Duration {
-	invoice.timestamp().duration_since(SystemTime::UNIX_EPOCH).unwrap() + invoice.expiry_time()
+	invoice.signed_invoice.raw_invoice.data.timestamp.0 + invoice.expiry_time()
 }
 
-fn has_expired(params: &RouteParameters) -> bool {
-	if let Some(expiry_time) = params.payee.expiry_time {
+#[cfg(feature = "std")]
+fn has_expired(route_params: &RouteParameters) -> bool {
+	if let Some(expiry_time) = route_params.payment_params.expiry_time {
 		Invoice::is_expired_from_epoch(&SystemTime::UNIX_EPOCH, Duration::from_secs(expiry_time))
 	} else { false }
 }
 
-impl<P: Deref, R, S: Deref, L: Deref, E> EventHandler for InvoicePayer<P, R, S, L, E>
+impl<P: Deref, R, S: Deref, L: Deref, E: EventHandler, T: Time> EventHandler for InvoicePayerUsingTime<P, R, S, L, E, T>
 where
 	P::Target: Payer,
 	R: for <'a> Router<<<S as Deref>::Target as LockableScore<'a>>::Locked>,
 	S::Target: for <'a> LockableScore<'a>,
 	L::Target: Logger,
-	E: EventHandler,
 {
 	fn handle_event(&self, event: &Event) {
 		match event {
 			Event::PaymentPathFailed {
-				all_paths_failed, payment_id, payment_hash, rejected_by_dest, path,
-				short_channel_id, retry, ..
+				payment_id, payment_hash, rejected_by_dest, path, short_channel_id, retry, ..
 			} => {
 				if let Some(short_channel_id) = short_channel_id {
 					let path = path.iter().collect::<Vec<_>>();
 					self.scorer.lock().payment_path_failed(&path, *short_channel_id);
 				}
 
-				if *rejected_by_dest {
-					log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0));
-				} else if payment_id.is_none() {
+				if payment_id.is_none() {
 					log_trace!(self.logger, "Payment {} has no id; not retrying", log_bytes!(payment_hash.0));
+				} else if *rejected_by_dest {
+					log_trace!(self.logger, "Payment {} rejected by destination; not retrying", log_bytes!(payment_hash.0));
+					self.payer.abandon_payment(payment_id.unwrap());
 				} else if retry.is_none() {
 					log_trace!(self.logger, "Payment {} missing retry params; not retrying", log_bytes!(payment_hash.0));
+					self.payer.abandon_payment(payment_id.unwrap());
 				} else if self.retry_payment(payment_id.unwrap(), *payment_hash, retry.as_ref().unwrap()).is_ok() {
 					// We retried at least somewhat, don't provide the PaymentPathFailed event to the user.
 					return;
+				} else {
+					self.payer.abandon_payment(payment_id.unwrap());
 				}
-
-				if *all_paths_failed { self.payment_cache.lock().unwrap().remove(payment_hash); }
+			},
+			Event::PaymentFailed { payment_hash, .. } => {
+				self.remove_cached_payment(&payment_hash);
+			},
+			Event::PaymentPathSuccessful { path, .. } => {
+				let path = path.iter().collect::<Vec<_>>();
+				self.scorer.lock().payment_path_successful(&path);
 			},
 			Event::PaymentSent { payment_hash, .. } => {
 				let mut payment_cache = self.payment_cache.lock().unwrap();
 				let attempts = payment_cache
 					.remove(payment_hash)
-					.map_or(1, |attempts| attempts + 1);
+					.map_or(1, |attempts| attempts.count + 1);
 				log_trace!(self.logger, "Payment {} succeeded (attempts: {})", log_bytes!(payment_hash.0), attempts);
 			},
+			Event::ProbeSuccessful { payment_hash, path, .. } => {
+				log_trace!(self.logger, "Probe payment {} of {}msat was successful", log_bytes!(payment_hash.0), path.last().unwrap().fee_msat);
+				let path = path.iter().collect::<Vec<_>>();
+				self.scorer.lock().probe_successful(&path);
+			},
+			Event::ProbeFailed { payment_hash, path, short_channel_id, .. } => {
+				if let Some(short_channel_id) = short_channel_id {
+					log_trace!(self.logger, "Probe payment {} of {}msat failed at channel {}", log_bytes!(payment_hash.0), path.last().unwrap().fee_msat, *short_channel_id);
+					let path = path.iter().collect::<Vec<_>>();
+					self.scorer.lock().probe_failed(&path, *short_channel_id);
+				}
+			},
 			_ => {},
 		}
 
@@ -492,69 +609,84 @@ where
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use crate::{DEFAULT_EXPIRY_TIME, InvoiceBuilder, Currency};
-	use utils::create_invoice_from_channelmanager;
+	use crate::{InvoiceBuilder, Currency};
+	use utils::create_invoice_from_channelmanager_and_duration_since_epoch;
 	use bitcoin_hashes::sha256::Hash as Sha256;
 	use lightning::ln::PaymentPreimage;
 	use lightning::ln::features::{ChannelFeatures, NodeFeatures, InitFeatures};
 	use lightning::ln::functional_test_utils::*;
-	use lightning::ln::msgs::{ErrorAction, LightningError};
-	use lightning::routing::network_graph::NodeId;
-	use lightning::routing::router::{Payee, Route, RouteHop};
+	use lightning::ln::msgs::{ChannelMessageHandler, ErrorAction, LightningError};
+	use lightning::routing::gossip::NodeId;
+	use lightning::routing::router::{PaymentParameters, Route, RouteHop};
+	use lightning::routing::scoring::ChannelUsage;
 	use lightning::util::test_utils::TestLogger;
 	use lightning::util::errors::APIError;
-	use lightning::util::events::{Event, MessageSendEventsProvider};
+	use lightning::util::events::{Event, EventsProvider, MessageSendEvent, MessageSendEventsProvider};
 	use secp256k1::{SecretKey, PublicKey, Secp256k1};
 	use std::cell::RefCell;
 	use std::collections::VecDeque;
 	use std::time::{SystemTime, Duration};
+	use time_utils::tests::SinceEpoch;
+	use DEFAULT_EXPIRY_TIME;
 
 	fn invoice(payment_preimage: PaymentPreimage) -> Invoice {
 		let payment_hash = Sha256::hash(&payment_preimage.0);
 		let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
+
 		InvoiceBuilder::new(Currency::Bitcoin)
 			.description("test".into())
 			.payment_hash(payment_hash)
 			.payment_secret(PaymentSecret([0; 32]))
-			.current_timestamp()
+			.duration_since_epoch(duration_since_epoch())
 			.min_final_cltv_expiry(144)
 			.amount_milli_satoshis(128)
 			.build_signed(|hash| {
-				Secp256k1::new().sign_recoverable(hash, &private_key)
+				Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 			})
 			.unwrap()
 	}
 
+	fn duration_since_epoch() -> Duration {
+		#[cfg(feature = "std")]
+			let duration_since_epoch =
+			SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap();
+		#[cfg(not(feature = "std"))]
+			let duration_since_epoch = Duration::from_secs(1234567);
+		duration_since_epoch
+	}
+
 	fn zero_value_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 		let payment_hash = Sha256::hash(&payment_preimage.0);
 		let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
+
 		InvoiceBuilder::new(Currency::Bitcoin)
 			.description("test".into())
 			.payment_hash(payment_hash)
 			.payment_secret(PaymentSecret([0; 32]))
-			.current_timestamp()
+			.duration_since_epoch(duration_since_epoch())
 			.min_final_cltv_expiry(144)
 			.build_signed(|hash| {
-				Secp256k1::new().sign_recoverable(hash, &private_key)
+				Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 			})
 			.unwrap()
 	}
 
+	#[cfg(feature = "std")]
 	fn expired_invoice(payment_preimage: PaymentPreimage) -> Invoice {
 		let payment_hash = Sha256::hash(&payment_preimage.0);
 		let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
-		let timestamp = SystemTime::now()
+		let duration = duration_since_epoch()
 			.checked_sub(Duration::from_secs(DEFAULT_EXPIRY_TIME * 2))
 			.unwrap();
 		InvoiceBuilder::new(Currency::Bitcoin)
 			.description("test".into())
 			.payment_hash(payment_hash)
 			.payment_secret(PaymentSecret([0; 32]))
-			.timestamp(timestamp)
+			.duration_since_epoch(duration)
 			.min_final_cltv_expiry(144)
 			.amount_milli_satoshis(128)
 			.build_signed(|hash| {
-				Secp256k1::new().sign_recoverable(hash, &private_key)
+				Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
 			})
 			.unwrap()
 	}
@@ -578,7 +710,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(0));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -607,7 +739,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -652,7 +784,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		assert!(invoice_payer.pay_invoice(&invoice).is_ok());
 	}
@@ -674,7 +806,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(PaymentId([1; 32]));
 		let event = Event::PaymentPathFailed {
@@ -703,7 +835,7 @@ mod tests {
 	}
 
 	#[test]
-	fn fails_paying_invoice_after_max_retries() {
+	fn fails_paying_invoice_after_max_retry_counts() {
 		let event_handled = core::cell::RefCell::new(false);
 		let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
 
@@ -719,7 +851,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -759,6 +891,52 @@ mod tests {
 		assert_eq!(*payer.attempts.borrow(), 3);
 	}
 
+	#[cfg(feature = "std")]
+	#[test]
+	fn fails_paying_invoice_after_max_retry_timeout() {
+		let event_handled = core::cell::RefCell::new(false);
+		let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
+
+		let payment_preimage = PaymentPreimage([1; 32]);
+		let invoice = invoice(payment_preimage);
+		let final_value_msat = invoice.amount_milli_satoshis().unwrap();
+
+		let payer = TestPayer::new()
+			.expect_send(Amount::ForInvoice(final_value_msat))
+			.expect_send(Amount::OnRetry(final_value_msat / 2));
+
+		let router = TestRouter {};
+		let scorer = RefCell::new(TestScorer::new());
+		let logger = TestLogger::new();
+		type InvoicePayerUsingSinceEpoch <P, R, S, L, E> = InvoicePayerUsingTime::<P, R, S, L, E, SinceEpoch>;
+
+		let invoice_payer =
+			InvoicePayerUsingSinceEpoch::new(&payer, router, &scorer, &logger, event_handler, Retry::Timeout(Duration::from_secs(120)));
+
+		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
+		assert_eq!(*payer.attempts.borrow(), 1);
+
+		let event = Event::PaymentPathFailed {
+			payment_id,
+			payment_hash: PaymentHash(invoice.payment_hash().clone().into_inner()),
+			network_update: None,
+			rejected_by_dest: false,
+			all_paths_failed: true,
+			path: TestRouter::path_for_value(final_value_msat),
+			short_channel_id: None,
+			retry: Some(TestRouter::retry_for_invoice(&invoice)),
+		};
+		invoice_payer.handle_event(&event);
+		assert_eq!(*event_handled.borrow(), false);
+		assert_eq!(*payer.attempts.borrow(), 2);
+
+		SinceEpoch::advance(Duration::from_secs(121));
+
+		invoice_payer.handle_event(&event);
+		assert_eq!(*event_handled.borrow(), true);
+		assert_eq!(*payer.attempts.borrow(), 2);
+	}
+
 	#[test]
 	fn fails_paying_invoice_with_missing_retry_params() {
 		let event_handled = core::cell::RefCell::new(false);
@@ -773,7 +951,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -793,6 +971,8 @@ mod tests {
 		assert_eq!(*payer.attempts.borrow(), 1);
 	}
 
+	// Expiration is checked only in an std environment
+	#[cfg(feature = "std")]
 	#[test]
 	fn fails_paying_invoice_after_expiration() {
 		let event_handled = core::cell::RefCell::new(false);
@@ -803,7 +983,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_preimage = PaymentPreimage([1; 32]);
 		let invoice = expired_invoice(payment_preimage);
@@ -812,6 +992,8 @@ mod tests {
 		} else { panic!("Expected Invoice Error"); }
 	}
 
+	// Expiration is checked only in an std environment
+	#[cfg(feature = "std")]
 	#[test]
 	fn fails_retrying_invoice_after_expiration() {
 		let event_handled = core::cell::RefCell::new(false);
@@ -826,13 +1008,13 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
 
 		let mut retry_data = TestRouter::retry_for_invoice(&invoice);
-		retry_data.payee.expiry_time = Some(SystemTime::now()
+		retry_data.payment_params.expiry_time = Some(SystemTime::now()
 			.checked_sub(Duration::from_secs(2)).unwrap()
 			.duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs());
 		let event = Event::PaymentPathFailed {
@@ -867,7 +1049,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -901,7 +1083,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		assert_eq!(*payer.attempts.borrow(), 1);
@@ -937,7 +1119,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(0));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 
@@ -976,7 +1158,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, Retry::Attempts(0));
 
 		let payment_preimage = PaymentPreimage([1; 32]);
 		let invoice = invoice(payment_preimage);
@@ -1000,7 +1182,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, |_: &_| {}, Retry::Attempts(0));
 
 		match invoice_payer.pay_invoice(&invoice) {
 			Err(PaymentError::Sending(_)) => {},
@@ -1024,7 +1206,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(0));
 
 		let payment_id =
 			Some(invoice_payer.pay_zero_value_invoice(&invoice, final_value_msat).unwrap());
@@ -1047,7 +1229,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(0));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(0));
 
 		let payment_preimage = PaymentPreimage([1; 32]);
 		let invoice = invoice(payment_preimage);
@@ -1078,7 +1260,7 @@ mod tests {
 		let scorer = RefCell::new(TestScorer::new());
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_pubkey(
 				pubkey, payment_preimage, final_value_msat, final_cltv_expiry_delta
@@ -1086,7 +1268,7 @@ mod tests {
 		assert_eq!(*payer.attempts.borrow(), 1);
 
 		let retry = RouteParameters {
-			payee: Payee::for_keysend(pubkey),
+			payment_params: PaymentParameters::for_keysend(pubkey),
 			final_value_msat,
 			final_cltv_expiry_delta,
 		};
@@ -1128,10 +1310,12 @@ mod tests {
 			.expect_send(Amount::ForInvoice(final_value_msat))
 			.expect_send(Amount::OnRetry(final_value_msat / 2));
 		let router = TestRouter {};
-		let scorer = RefCell::new(TestScorer::new().expect_channel_failure(short_channel_id.unwrap()));
+		let scorer = RefCell::new(TestScorer::new().expect(TestResult::PaymentFailure {
+			path: path.clone(), short_channel_id: path[0].short_channel_id,
+		}));
 		let logger = TestLogger::new();
 		let invoice_payer =
-			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, RetryAttempts(2));
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
 
 		let payment_id = Some(invoice_payer.pay_invoice(&invoice).unwrap());
 		let event = Event::PaymentPathFailed {
@@ -1147,6 +1331,39 @@ mod tests {
 		invoice_payer.handle_event(&event);
 	}
 
+	#[test]
+	fn scores_successful_channels() {
+		let event_handled = core::cell::RefCell::new(false);
+		let event_handler = |_: &_| { *event_handled.borrow_mut() = true; };
+
+		let payment_preimage = PaymentPreimage([1; 32]);
+		let invoice = invoice(payment_preimage);
+		let payment_hash = Some(PaymentHash(invoice.payment_hash().clone().into_inner()));
+		let final_value_msat = invoice.amount_milli_satoshis().unwrap();
+		let route = TestRouter::route_for_value(final_value_msat);
+
+		// Expect that scorer is given short_channel_id upon handling the event.
+		let payer = TestPayer::new().expect_send(Amount::ForInvoice(final_value_msat));
+		let router = TestRouter {};
+		let scorer = RefCell::new(TestScorer::new()
+			.expect(TestResult::PaymentSuccess { path: route.paths[0].clone() })
+			.expect(TestResult::PaymentSuccess { path: route.paths[1].clone() })
+		);
+		let logger = TestLogger::new();
+		let invoice_payer =
+			InvoicePayer::new(&payer, router, &scorer, &logger, event_handler, Retry::Attempts(2));
+
+		let payment_id = invoice_payer.pay_invoice(&invoice).unwrap();
+		let event = Event::PaymentPathSuccessful {
+			payment_id, payment_hash, path: route.paths[0].clone()
+		};
+		invoice_payer.handle_event(&event);
+		let event = Event::PaymentPathSuccessful {
+			payment_id, payment_hash, path: route.paths[1].clone()
+		};
+		invoice_payer.handle_event(&event);
+	}
+
 	struct TestRouter;
 
 	impl TestRouter {
@@ -1166,7 +1383,7 @@ mod tests {
 						short_channel_id: 1, fee_msat: final_value_msat / 2, cltv_expiry_delta: 144
 					}],
 				],
-				payee: None,
+				payment_params: None,
 			}
 		}
 
@@ -1175,15 +1392,15 @@ mod tests {
 		}
 
 		fn retry_for_invoice(invoice: &Invoice) -> RouteParameters {
-			let mut payee = Payee::from_node_id(invoice.recover_payee_pub_key())
+			let mut payment_params = PaymentParameters::from_node_id(invoice.recover_payee_pub_key())
 				.with_expiry_time(expiry_time_from_unix_epoch(invoice).as_secs())
 				.with_route_hints(invoice.route_hints());
 			if let Some(features) = invoice.features() {
-				payee = payee.with_features(features.clone());
+				payment_params = payment_params.with_features(features.clone());
 			}
 			let final_value_msat = invoice.amount_milli_satoshis().unwrap() / 2;
 			RouteParameters {
-				payee,
+				payment_params,
 				final_value_msat,
 				final_cltv_expiry_delta: invoice.min_final_cltv_expiry() as u32,
 			}
@@ -1192,11 +1409,11 @@ mod tests {
 
 	impl<S: Score> Router<S> for TestRouter {
 		fn find_route(
-			&self, _payer: &PublicKey, params: &RouteParameters, _payment_hash: &PaymentHash,
+			&self, _payer: &PublicKey, route_params: &RouteParameters, _payment_hash: &PaymentHash,
 			_first_hops: Option<&[&ChannelDetails]>, _scorer: &S
 		) -> Result<Route, LightningError> {
 			Ok(Route {
-				payee: Some(params.payee.clone()), ..Self::route_for_value(params.final_value_msat)
+				payment_params: Some(route_params.payment_params.clone()), ..Self::route_for_value(route_params.final_value_msat)
 			})
 		}
 	}
@@ -1213,18 +1430,24 @@ mod tests {
 	}
 
 	struct TestScorer {
-		expectations: VecDeque<u64>,
+		expectations: Option<VecDeque<TestResult>>,
+	}
+
+	#[derive(Debug)]
+	enum TestResult {
+		PaymentFailure { path: Vec<RouteHop>, short_channel_id: u64 },
+		PaymentSuccess { path: Vec<RouteHop> },
 	}
 
 	impl TestScorer {
 		fn new() -> Self {
 			Self {
-				expectations: VecDeque::new(),
+				expectations: None,
 			}
 		}
 
-		fn expect_channel_failure(mut self, short_channel_id: u64) -> Self {
-			self.expectations.push_back(short_channel_id);
+		fn expect(mut self, expectation: TestResult) -> Self {
+			self.expectations.get_or_insert_with(|| VecDeque::new()).push_back(expectation);
 			self
 		}
 	}
@@ -1233,14 +1456,65 @@ mod tests {
 	impl lightning::util::ser::Writeable for TestScorer {
 		fn write<W: lightning::util::ser::Writer>(&self, _: &mut W) -> Result<(), std::io::Error> { unreachable!(); }
 	}
+
 	impl Score for TestScorer {
 		fn channel_penalty_msat(
-			&self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId
+			&self, _short_channel_id: u64, _source: &NodeId, _target: &NodeId, _usage: ChannelUsage
 		) -> u64 { 0 }
 
-		fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
-			if let Some(expected_short_channel_id) = self.expectations.pop_front() {
-				assert_eq!(short_channel_id, expected_short_channel_id);
+		fn payment_path_failed(&mut self, actual_path: &[&RouteHop], actual_short_channel_id: u64) {
+			if let Some(expectations) = &mut self.expectations {
+				match expectations.pop_front() {
+					Some(TestResult::PaymentFailure { path, short_channel_id }) => {
+						assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
+						assert_eq!(actual_short_channel_id, short_channel_id);
+					},
+					Some(TestResult::PaymentSuccess { path }) => {
+						panic!("Unexpected successful payment path: {:?}", path)
+					},
+					None => panic!("Unexpected payment_path_failed call: {:?}", actual_path),
+				}
+			}
+		}
+
+		fn payment_path_successful(&mut self, actual_path: &[&RouteHop]) {
+			if let Some(expectations) = &mut self.expectations {
+				match expectations.pop_front() {
+					Some(TestResult::PaymentFailure { path, .. }) => {
+						panic!("Unexpected payment path failure: {:?}", path)
+					},
+					Some(TestResult::PaymentSuccess { path }) => {
+						assert_eq!(actual_path, &path.iter().collect::<Vec<_>>()[..]);
+					},
+					None => panic!("Unexpected payment_path_successful call: {:?}", actual_path),
+				}
+			}
+		}
+
+		fn probe_failed(&mut self, actual_path: &[&RouteHop], _: u64) {
+			if let Some(expectations) = &mut self.expectations {
+				match expectations.pop_front() {
+					Some(TestResult::PaymentFailure { path, .. }) => {
+						panic!("Unexpected failed payment path: {:?}", path)
+					},
+					Some(TestResult::PaymentSuccess { path }) => {
+						panic!("Unexpected successful payment path: {:?}", path)
+					},
+					None => panic!("Unexpected payment_path_failed call: {:?}", actual_path),
+				}
+			}
+		}
+		fn probe_successful(&mut self, actual_path: &[&RouteHop]) {
+			if let Some(expectations) = &mut self.expectations {
+				match expectations.pop_front() {
+					Some(TestResult::PaymentFailure { path, .. }) => {
+						panic!("Unexpected payment path failure: {:?}", path)
+					},
+					Some(TestResult::PaymentSuccess { path }) => {
+						panic!("Unexpected successful payment path: {:?}", path)
+					},
+					None => panic!("Unexpected payment_path_successful call: {:?}", actual_path),
+				}
 			}
 		}
 	}
@@ -1251,8 +1525,10 @@ mod tests {
 				return;
 			}
 
-			if !self.expectations.is_empty() {
-				panic!("Unsatisfied channel failure expectations: {:?}", self.expectations);
+			if let Some(expectations) = &self.expectations {
+				if !expectations.is_empty() {
+					panic!("Unsatisfied scorer expectations: {:?}", expectations);
+				}
 			}
 		}
 	}
@@ -1367,6 +1643,8 @@ mod tests {
 			self.check_value_msats(Amount::OnRetry(route.get_total_amount()));
 			self.check_attempts().map(|_| ())
 		}
+
+		fn abandon_payment(&self, _payment_id: PaymentId) { }
 	}
 
 	// *** Full Featured Functional Tests with a Real ChannelManager ***
@@ -1424,7 +1702,7 @@ mod tests {
 					cltv_expiry_delta: 100,
 				}],
 			],
-			payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
+			payment_params: Some(PaymentParameters::from_node_id(nodes[1].node.get_our_node_id())),
 		};
 		let router = ManualRouter(RefCell::new(VecDeque::new()));
 		router.expect_find_route(Ok(route.clone()));
@@ -1435,10 +1713,11 @@ mod tests {
 
 		let event_handler = |_: &_| { panic!(); };
 		let scorer = RefCell::new(TestScorer::new());
-		let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
+		let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, Retry::Attempts(1));
 
-		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
-			&nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
+		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
+			&nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string(),
+			duration_since_epoch(), 3600).unwrap())
 			.is_ok());
 		let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(htlc_msgs.len(), 2);
@@ -1467,7 +1746,7 @@ mod tests {
 					cltv_expiry_delta: 100,
 				}],
 			],
-			payee: Some(Payee::from_node_id(nodes[1].node.get_our_node_id())),
+			payment_params: Some(PaymentParameters::from_node_id(nodes[1].node.get_our_node_id())),
 		};
 		let router = ManualRouter(RefCell::new(VecDeque::new()));
 		router.expect_find_route(Ok(route.clone()));
@@ -1480,13 +1759,188 @@ mod tests {
 
 		let event_handler = |_: &_| { panic!(); };
 		let scorer = RefCell::new(TestScorer::new());
-		let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, RetryAttempts(1));
+		let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, Retry::Attempts(1));
 
-		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager(
-			&nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string()).unwrap())
+		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
+			&nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string(),
+			duration_since_epoch(), 3600).unwrap())
 			.is_ok());
 		let htlc_msgs = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(htlc_msgs.len(), 2);
 		check_added_monitors!(nodes[0], 2);
 	}
+
+	#[test]
+	fn no_extra_retries_on_back_to_back_fail() {
+		// In a previous release, we had a race where we may exceed the payment retry count if we
+		// get two failures in a row with the second having `all_paths_failed` set.
+		// Generally, when we give up trying to retry a payment, we don't know for sure what the
+		// current state of the ChannelManager event queue is. Specifically, we cannot be sure that
+		// there are not multiple additional `PaymentPathFailed` or even `PaymentSent` events
+		// pending which we will see later. Thus, when we previously removed the retry tracking map
+		// entry after a `all_paths_failed` `PaymentPathFailed` event, we may have dropped the
+		// retry entry even though more events for the same payment were still pending. This led to
+		// us retrying a payment again even though we'd already given up on it.
+		//
+		// We now have a separate event - `PaymentFailed` which indicates no HTLCs remain and which
+		// is used to remove the payment retry counter entries instead. This tests for the specific
+		// excess-retry case while also testing `PaymentFailed` generation.
+
+		let chanmon_cfgs = create_chanmon_cfgs(3);
+		let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+		let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+		let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+
+		let chan_1_scid = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 10_000_000, 0, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+		let chan_2_scid = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 10_000_000, 0, InitFeatures::known(), InitFeatures::known()).0.contents.short_channel_id;
+
+		let mut route = Route {
+			paths: vec![
+				vec![RouteHop {
+					pubkey: nodes[1].node.get_our_node_id(),
+					node_features: NodeFeatures::known(),
+					short_channel_id: chan_1_scid,
+					channel_features: ChannelFeatures::known(),
+					fee_msat: 0,
+					cltv_expiry_delta: 100,
+				}, RouteHop {
+					pubkey: nodes[2].node.get_our_node_id(),
+					node_features: NodeFeatures::known(),
+					short_channel_id: chan_2_scid,
+					channel_features: ChannelFeatures::known(),
+					fee_msat: 100_000_000,
+					cltv_expiry_delta: 100,
+				}],
+				vec![RouteHop {
+					pubkey: nodes[1].node.get_our_node_id(),
+					node_features: NodeFeatures::known(),
+					short_channel_id: chan_1_scid,
+					channel_features: ChannelFeatures::known(),
+					fee_msat: 0,
+					cltv_expiry_delta: 100,
+				}, RouteHop {
+					pubkey: nodes[2].node.get_our_node_id(),
+					node_features: NodeFeatures::known(),
+					short_channel_id: chan_2_scid,
+					channel_features: ChannelFeatures::known(),
+					fee_msat: 100_000_000,
+					cltv_expiry_delta: 100,
+				}]
+			],
+			payment_params: Some(PaymentParameters::from_node_id(nodes[2].node.get_our_node_id())),
+		};
+		let router = ManualRouter(RefCell::new(VecDeque::new()));
+		router.expect_find_route(Ok(route.clone()));
+		// On retry, we'll only be asked for one path
+		route.paths.remove(1);
+		router.expect_find_route(Ok(route.clone()));
+
+		let expected_events: RefCell<VecDeque<&dyn Fn(&Event)>> = RefCell::new(VecDeque::new());
+		let event_handler = |event: &Event| {
+			let event_checker = expected_events.borrow_mut().pop_front().unwrap();
+			event_checker(event);
+		};
+		let scorer = RefCell::new(TestScorer::new());
+		let invoice_payer = InvoicePayer::new(nodes[0].node, router, &scorer, nodes[0].logger, event_handler, Retry::Attempts(1));
+
+		assert!(invoice_payer.pay_invoice(&create_invoice_from_channelmanager_and_duration_since_epoch(
+			&nodes[1].node, nodes[1].keys_manager, Currency::Bitcoin, Some(100_010_000), "Invoice".to_string(),
+			duration_since_epoch(), 3600).unwrap())
+			.is_ok());
+		let htlc_updates = SendEvent::from_node(&nodes[0]);
+		check_added_monitors!(nodes[0], 1);
+		assert_eq!(htlc_updates.msgs.len(), 1);
+
+		nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &htlc_updates.msgs[0]);
+		nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &htlc_updates.commitment_msg);
+		check_added_monitors!(nodes[1], 1);
+		let (bs_first_raa, bs_first_cs) = get_revoke_commit_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+		nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_first_raa);
+		check_added_monitors!(nodes[0], 1);
+		let second_htlc_updates = SendEvent::from_node(&nodes[0]);
+
+		nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_first_cs);
+		check_added_monitors!(nodes[0], 1);
+		let as_first_raa = get_event_msg!(nodes[0], MessageSendEvent::SendRevokeAndACK, nodes[1].node.get_our_node_id());
+
+		nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &second_htlc_updates.msgs[0]);
+		nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &second_htlc_updates.commitment_msg);
+		check_added_monitors!(nodes[1], 1);
+		let bs_second_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+		nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_first_raa);
+		check_added_monitors!(nodes[1], 1);
+		let bs_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+		nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_second_raa);
+		check_added_monitors!(nodes[0], 1);
+
+		nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_fail_update.update_fail_htlcs[0]);
+		nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_fail_update.commitment_signed);
+		check_added_monitors!(nodes[0], 1);
+		let (as_second_raa, as_third_cs) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+		nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_second_raa);
+		check_added_monitors!(nodes[1], 1);
+		let bs_second_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+		nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_third_cs);
+		check_added_monitors!(nodes[1], 1);
+		let bs_third_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+		nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_second_fail_update.update_fail_htlcs[0]);
+		nodes[0].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bs_second_fail_update.commitment_signed);
+		check_added_monitors!(nodes[0], 1);
+
+		nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_third_raa);
+		check_added_monitors!(nodes[0], 1);
+		let (as_third_raa, as_fourth_cs) = get_revoke_commit_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+		nodes[1].node.handle_revoke_and_ack(&nodes[0].node.get_our_node_id(), &as_third_raa);
+		check_added_monitors!(nodes[1], 1);
+		nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &as_fourth_cs);
+		check_added_monitors!(nodes[1], 1);
+		let bs_fourth_raa = get_event_msg!(nodes[1], MessageSendEvent::SendRevokeAndACK, nodes[0].node.get_our_node_id());
+
+		nodes[0].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bs_fourth_raa);
+		check_added_monitors!(nodes[0], 1);
+
+		// At this point A has sent two HTLCs which both failed due to lack of fee. It now has two
+		// pending `PaymentPathFailed` events, one with `all_paths_failed` unset, and the second
+		// with it set. The first event will use up the only retry we are allowed, with the second
+		// `PaymentPathFailed` being passed up to the user (us, in this case). Previously, we'd
+		// treated this as "HTLC complete" and dropped the retry counter, causing us to retry again
+		// if the final HTLC failed.
+		expected_events.borrow_mut().push_back(&|ev: &Event| {
+			if let Event::PaymentPathFailed { rejected_by_dest, all_paths_failed, .. } = ev {
+				assert!(!rejected_by_dest);
+				assert!(all_paths_failed);
+			} else { panic!("Unexpected event"); }
+		});
+		nodes[0].node.process_pending_events(&invoice_payer);
+		assert!(expected_events.borrow().is_empty());
+
+		let retry_htlc_updates = SendEvent::from_node(&nodes[0]);
+		check_added_monitors!(nodes[0], 1);
+
+		nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &retry_htlc_updates.msgs[0]);
+		commitment_signed_dance!(nodes[1], nodes[0], &retry_htlc_updates.commitment_msg, false, true);
+		let bs_fail_update = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+		nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &bs_fail_update.update_fail_htlcs[0]);
+		commitment_signed_dance!(nodes[0], nodes[1], &bs_fail_update.commitment_signed, false, true);
+
+		expected_events.borrow_mut().push_back(&|ev: &Event| {
+			if let Event::PaymentPathFailed { rejected_by_dest, all_paths_failed, .. } = ev {
+				assert!(!rejected_by_dest);
+				assert!(all_paths_failed);
+			} else { panic!("Unexpected event"); }
+		});
+		expected_events.borrow_mut().push_back(&|ev: &Event| {
+			if let Event::PaymentFailed { .. } = ev {
+			} else { panic!("Unexpected event"); }
+		});
+		nodes[0].node.process_pending_events(&invoice_payer);
+		assert!(expected_events.borrow().is_empty());
+	}
 }