Merge pull request #2198 from TheBlueMatt/2023-04-fewer-disables
[rust-lightning] / lightning / src / ln / outbound_payment.rs
index c1e3f27c1e88a0d6622d55e3c6632ae156b3b19a..8dfdf7611b3b653a069f4f90c332208596e72c17 100644 (file)
@@ -14,7 +14,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::secp256k1::{self, Secp256k1, SecretKey};
 
 use crate::chain::keysinterface::{EntropySource, NodeSigner, Recipient};
-use crate::events;
+use crate::events::{self, PaymentFailureReason};
 use crate::ln::{PaymentHash, PaymentPreimage, PaymentSecret};
 use crate::ln::channelmanager::{ChannelDetails, HTLCSource, IDEMPOTENCY_TIMEOUT_TICKS, PaymentId};
 use crate::ln::onion_utils::HTLCFailReason;
@@ -68,6 +68,8 @@ pub(crate) enum PendingOutboundPayment {
        Abandoned {
                session_privs: HashSet<[u8; 32]>,
                payment_hash: PaymentHash,
+               /// Will be `None` if the payment was serialized before 0.0.115.
+               reason: Option<PaymentFailureReason>,
        },
 }
 
@@ -145,21 +147,16 @@ impl PendingOutboundPayment {
                *self = PendingOutboundPayment::Fulfilled { session_privs, payment_hash, timer_ticks_without_htlcs: 0 };
        }
 
-       fn mark_abandoned(&mut self) -> Result<(), ()> {
-               let mut session_privs = HashSet::new();
-               let our_payment_hash;
-               core::mem::swap(&mut session_privs, match self {
-                       PendingOutboundPayment::Legacy { .. } |
-                       PendingOutboundPayment::Fulfilled { .. } =>
-                               return Err(()),
-                       PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } |
-                       PendingOutboundPayment::Abandoned { session_privs, payment_hash, .. } => {
-                               our_payment_hash = *payment_hash;
-                               session_privs
-                       },
-               });
-               *self = PendingOutboundPayment::Abandoned { session_privs, payment_hash: our_payment_hash };
-               Ok(())
+       fn mark_abandoned(&mut self, reason: PaymentFailureReason) {
+               if let PendingOutboundPayment::Retryable { session_privs, payment_hash, .. } = self {
+                       let mut our_session_privs = HashSet::new();
+                       core::mem::swap(&mut our_session_privs, session_privs);
+                       *self = PendingOutboundPayment::Abandoned {
+                               session_privs: our_session_privs,
+                               payment_hash: *payment_hash,
+                               reason: Some(reason)
+                       };
+               }
        }
 
        /// panics if path is None and !self.is_fulfilled
@@ -417,6 +414,10 @@ pub struct RecipientOnionFields {
        ///
        /// If you do not have one, the [`Route`] you pay over must not contain multiple paths as
        /// multi-path payments require a recipient-provided secret.
+       ///
+       /// Note that for spontaneous payments most lightning nodes do not currently support MPP
+       /// receives, thus you should generally never be providing a secret here for spontaneous
+       /// payments.
        pub payment_secret: Option<PaymentSecret>,
 }
 
@@ -452,7 +453,7 @@ impl OutboundPayments {
        }
 
        pub(super) fn send_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
-               &self, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>, payment_id: PaymentId,
+               &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
                retry_strategy: Retry, route_params: RouteParameters, router: &R,
                first_hops: Vec<ChannelDetails>, compute_inflight_htlcs: IH, entropy_source: &ES,
                node_signer: &NS, best_block_height: u32, logger: &L,
@@ -464,34 +465,34 @@ impl OutboundPayments {
                NS::Target: NodeSigner,
                L::Target: Logger,
                IH: Fn() -> InFlightHtlcs,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
        {
-               self.send_payment_internal(payment_id, payment_hash, payment_secret, None, retry_strategy,
+               self.send_payment_internal(payment_id, payment_hash, recipient_onion, None, retry_strategy,
                        route_params, router, first_hops, &compute_inflight_htlcs, entropy_source, node_signer,
                        best_block_height, logger, pending_events, &send_payment_along_path)
        }
 
        pub(super) fn send_payment_with_route<ES: Deref, NS: Deref, F>(
-               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
                payment_id: PaymentId, entropy_source: &ES, node_signer: &NS, best_block_height: u32,
                send_payment_along_path: F
        ) -> Result<(), PaymentSendFailure>
        where
                ES::Target: EntropySource,
                NS::Target: NodeSigner,
-               F: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
-               let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret, payment_id, None, route, None, None, entropy_source, best_block_height)?;
-               self.pay_route_internal(route, payment_hash, payment_secret, None, payment_id, None,
+               let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(), payment_id, None, route, None, None, entropy_source, best_block_height)?;
+               self.pay_route_internal(route, payment_hash, recipient_onion, None, payment_id, None,
                        onion_session_privs, node_signer, best_block_height, &send_payment_along_path)
                        .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
        }
 
        pub(super) fn send_spontaneous_payment<R: Deref, ES: Deref, NS: Deref, IH, SP, L: Deref>(
-               &self, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
-               retry_strategy: Retry, route_params: RouteParameters, router: &R,
+               &self, payment_preimage: Option<PaymentPreimage>, recipient_onion: RecipientOnionFields,
+               payment_id: PaymentId, retry_strategy: Retry, route_params: RouteParameters, router: &R,
                first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
                node_signer: &NS, best_block_height: u32, logger: &L,
                pending_events: &Mutex<Vec<events::Event>>, send_payment_along_path: SP
@@ -502,34 +503,38 @@ impl OutboundPayments {
                NS::Target: NodeSigner,
                L::Target: Logger,
                IH: Fn() -> InFlightHtlcs,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
        {
                let preimage = payment_preimage
                        .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
                let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
-               self.send_payment_internal(payment_id, payment_hash, &None, Some(preimage), retry_strategy,
-                       route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer,
-                       best_block_height, logger, pending_events, send_payment_along_path)
+               self.send_payment_internal(payment_id, payment_hash, recipient_onion, Some(preimage),
+                       retry_strategy, route_params, router, first_hops, inflight_htlcs, entropy_source,
+                       node_signer, best_block_height, logger, pending_events, send_payment_along_path)
                        .map(|()| payment_hash)
        }
 
        pub(super) fn send_spontaneous_payment_with_route<ES: Deref, NS: Deref, F>(
-               &self, route: &Route, payment_preimage: Option<PaymentPreimage>, payment_id: PaymentId,
-               entropy_source: &ES, node_signer: &NS, best_block_height: u32, send_payment_along_path: F
+               &self, route: &Route, payment_preimage: Option<PaymentPreimage>,
+               recipient_onion: RecipientOnionFields, payment_id: PaymentId, entropy_source: &ES,
+               node_signer: &NS, best_block_height: u32, send_payment_along_path: F
        ) -> Result<PaymentHash, PaymentSendFailure>
        where
                ES::Target: EntropySource,
                NS::Target: NodeSigner,
-               F: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                let preimage = payment_preimage
                        .unwrap_or_else(|| PaymentPreimage(entropy_source.get_secure_random_bytes()));
                let payment_hash = PaymentHash(Sha256::hash(&preimage.0).into_inner());
-               let onion_session_privs = self.add_new_pending_payment(payment_hash, None, payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
+               let onion_session_privs = self.add_new_pending_payment(payment_hash, recipient_onion.clone(),
+                       payment_id, Some(preimage), &route, None, None, entropy_source, best_block_height)?;
 
-               match self.pay_route_internal(route, payment_hash, &None, Some(preimage), payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path) {
+               match self.pay_route_internal(route, payment_hash, recipient_onion, Some(preimage),
+                       payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
+               ) {
                        Ok(()) => Ok(payment_hash),
                        Err(e) => {
                                self.remove_outbound_if_all_failed(payment_id, &e);
@@ -547,7 +552,7 @@ impl OutboundPayments {
                R::Target: Router,
                ES::Target: EntropySource,
                NS::Target: NodeSigner,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>,
                IH: Fn() -> InFlightHtlcs,
                FH: Fn() -> Vec<ChannelDetails>,
@@ -580,10 +585,12 @@ impl OutboundPayments {
                outbounds.retain(|pmt_id, pmt| {
                        let mut retain = true;
                        if !pmt.is_auto_retryable_now() && pmt.remaining_parts() == 0 {
-                               if pmt.mark_abandoned().is_ok() {
+                               pmt.mark_abandoned(PaymentFailureReason::RetriesExhausted);
+                               if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = pmt {
                                        pending_events.lock().unwrap().push(events::Event::PaymentFailed {
                                                payment_id: *pmt_id,
-                                               payment_hash: pmt.payment_hash().expect("PendingOutboundPayments::Retryable always has a payment hash set"),
+                                               payment_hash: *payment_hash,
+                                               reason: *reason,
                                        });
                                        retain = false;
                                }
@@ -604,7 +611,7 @@ impl OutboundPayments {
        /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
        /// [`Event::PaymentFailed`]: crate::events::Event::PaymentFailed
        fn send_payment_internal<R: Deref, NS: Deref, ES: Deref, IH, SP, L: Deref>(
-               &self, payment_id: PaymentId, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               &self, payment_id: PaymentId, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
                keysend_preimage: Option<PaymentPreimage>, retry_strategy: Retry, route_params: RouteParameters,
                router: &R, first_hops: Vec<ChannelDetails>, inflight_htlcs: IH, entropy_source: &ES,
                node_signer: &NS, best_block_height: u32, logger: &L,
@@ -616,7 +623,7 @@ impl OutboundPayments {
                NS::Target: NodeSigner,
                L::Target: Logger,
                IH: Fn() -> InFlightHtlcs,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                #[cfg(feature = "std")] {
@@ -631,12 +638,12 @@ impl OutboundPayments {
                        payment_hash, payment_id,
                ).map_err(|_| RetryableSendFailure::RouteNotFound)?;
 
-               let onion_session_privs = self.add_new_pending_payment(payment_hash, *payment_secret,
-                       payment_id, keysend_preimage, &route, Some(retry_strategy),
+               let onion_session_privs = self.add_new_pending_payment(payment_hash,
+                       recipient_onion.clone(), payment_id, keysend_preimage, &route, Some(retry_strategy),
                        Some(route_params.payment_params.clone()), entropy_source, best_block_height)
                        .map_err(|_| RetryableSendFailure::DuplicatePayment)?;
 
-               let res = self.pay_route_internal(&route, payment_hash, payment_secret, None, payment_id, None,
+               let res = self.pay_route_internal(&route, payment_hash, recipient_onion, None, payment_id, None,
                        onion_session_privs, node_signer, best_block_height, &send_payment_along_path);
                log_info!(logger, "Result sending payment with id {}: {:?}", log_bytes!(payment_id.0), res);
                if let Err(e) = res {
@@ -657,13 +664,13 @@ impl OutboundPayments {
                NS::Target: NodeSigner,
                L::Target: Logger,
                IH: Fn() -> InFlightHtlcs,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                #[cfg(feature = "std")] {
                        if has_expired(&route_params) {
                                log_error!(logger, "Payment params expired on retry, abandoning payment {}", log_bytes!(payment_id.0));
-                               self.abandon_payment(payment_id, pending_events);
+                               self.abandon_payment(payment_id, PaymentFailureReason::PaymentExpired, pending_events);
                                return
                        }
                }
@@ -676,14 +683,14 @@ impl OutboundPayments {
                        Ok(route) => route,
                        Err(e) => {
                                log_error!(logger, "Failed to find a route on retry, abandoning payment {}: {:#?}", log_bytes!(payment_id.0), e);
-                               self.abandon_payment(payment_id, pending_events);
+                               self.abandon_payment(payment_id, PaymentFailureReason::RouteNotFound, pending_events);
                                return
                        }
                };
                for path in route.paths.iter() {
                        if path.len() == 0 {
                                log_error!(logger, "length-0 path in route");
-                               self.abandon_payment(payment_id, pending_events);
+                               self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
                                return
                        }
                }
@@ -695,17 +702,21 @@ impl OutboundPayments {
                }
 
                macro_rules! abandon_with_entry {
-                       ($payment: expr) => {
-                               if $payment.get_mut().mark_abandoned().is_ok() && $payment.get().remaining_parts() == 0 {
-                                       pending_events.lock().unwrap().push(events::Event::PaymentFailed {
-                                               payment_id,
-                                               payment_hash,
-                                       });
-                                       $payment.remove();
+                       ($payment: expr, $reason: expr) => {
+                               $payment.get_mut().mark_abandoned($reason);
+                               if let PendingOutboundPayment::Abandoned { reason, .. } = $payment.get() {
+                                       if $payment.get().remaining_parts() == 0 {
+                                               pending_events.lock().unwrap().push(events::Event::PaymentFailed {
+                                                       payment_id,
+                                                       payment_hash,
+                                                       reason: *reason,
+                                               });
+                                               $payment.remove();
+                                       }
                                }
                        }
                }
-               let (total_msat, payment_secret, keysend_preimage) = {
+               let (total_msat, recipient_onion, keysend_preimage) = {
                        let mut outbounds = self.pending_outbound_payments.lock().unwrap();
                        match outbounds.entry(payment_id) {
                                hash_map::Entry::Occupied(mut payment) => {
@@ -716,10 +727,12 @@ impl OutboundPayments {
                                                        let retry_amt_msat: u64 = route.paths.iter().map(|path| path.last().unwrap().fee_msat).sum();
                                                        if retry_amt_msat + *pending_amt_msat > *total_msat * (100 + RETRY_OVERFLOW_PERCENTAGE) / 100 {
                                                                log_error!(logger, "retry_amt_msat of {} will put pending_amt_msat (currently: {}) more than 10% over total_payment_amt_msat of {}", retry_amt_msat, pending_amt_msat, total_msat);
-                                                               abandon_with_entry!(payment);
+                                                               abandon_with_entry!(payment, PaymentFailureReason::UnexpectedError);
                                                                return
                                                        }
-                                                       (*total_msat, *payment_secret, *keysend_preimage)
+                                                       (*total_msat, RecipientOnionFields {
+                                                                       payment_secret: *payment_secret,
+                                                               }, *keysend_preimage)
                                                },
                                                PendingOutboundPayment::Legacy { .. } => {
                                                        log_error!(logger, "Unable to retry payments that were initially sent on LDK versions prior to 0.0.102");
@@ -736,7 +749,7 @@ impl OutboundPayments {
                                        };
                                        if !payment.get().is_retryable_now() {
                                                log_error!(logger, "Retries exhausted for payment id {}", log_bytes!(payment_id.0));
-                                               abandon_with_entry!(payment);
+                                               abandon_with_entry!(payment, PaymentFailureReason::RetriesExhausted);
                                                return
                                        }
                                        payment.get_mut().increment_attempts();
@@ -751,7 +764,7 @@ impl OutboundPayments {
                                }
                        }
                };
-               let res = self.pay_route_internal(&route, payment_hash, &payment_secret, keysend_preimage,
+               let res = self.pay_route_internal(&route, payment_hash, recipient_onion, keysend_preimage,
                        payment_id, Some(total_msat), onion_session_privs, node_signer, best_block_height,
                        &send_payment_along_path);
                log_info!(logger, "Result retrying payment id {}: {:?}", log_bytes!(payment_id.0), res);
@@ -772,16 +785,16 @@ impl OutboundPayments {
                NS::Target: NodeSigner,
                L::Target: Logger,
                IH: Fn() -> InFlightHtlcs,
-               SP: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               SP: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                match err {
                        PaymentSendFailure::AllFailedResendSafe(errs) => {
-                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, errs.into_iter().map(|e| Err(e)), pending_events);
+                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, errs.into_iter().map(|e| Err(e)), logger, pending_events);
                                self.retry_payment_internal(payment_hash, payment_id, route_params, router, first_hops, inflight_htlcs, entropy_source, node_signer, best_block_height, logger, pending_events, send_payment_along_path);
                        },
                        PaymentSendFailure::PartialFailure { failed_paths_retry: Some(mut retry), results, .. } => {
-                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), pending_events);
+                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut retry, route.paths, results.into_iter(), logger, pending_events);
                                // Some paths were sent, even if we failed to send the full MPP value our recipient may
                                // misbehave and claim the funds, at which point we have to consider the payment sent, so
                                // return `Ok()` here, ignoring any retry errors.
@@ -793,26 +806,28 @@ impl OutboundPayments {
                                // initial HTLC-Add messages yet.
                        },
                        PaymentSendFailure::PathParameterError(results) => {
-                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), pending_events);
-                               self.abandon_payment(payment_id, pending_events);
+                               log_error!(logger, "Failed to send to route due to parameter error in a single path. Your router is buggy");
+                               Self::push_path_failed_evs_and_scids(payment_id, payment_hash, &mut route_params, route.paths, results.into_iter(), logger, pending_events);
+                               self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
                        },
                        PaymentSendFailure::ParameterError(e) => {
                                log_error!(logger, "Failed to send to route due to parameter error: {:?}. Your router is buggy", e);
-                               self.abandon_payment(payment_id, pending_events);
+                               self.abandon_payment(payment_id, PaymentFailureReason::UnexpectedError, pending_events);
                        },
                        PaymentSendFailure::DuplicatePayment => debug_assert!(false), // unreachable
                }
        }
 
-       fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>>(
+       fn push_path_failed_evs_and_scids<I: ExactSizeIterator + Iterator<Item = Result<(), APIError>>, L: Deref>(
                payment_id: PaymentId, payment_hash: PaymentHash, route_params: &mut RouteParameters,
-               paths: Vec<Vec<RouteHop>>, path_results: I, pending_events: &Mutex<Vec<events::Event>>
-       ) {
+               paths: Vec<Vec<RouteHop>>, path_results: I, logger: &L, pending_events: &Mutex<Vec<events::Event>>
+       ) where L::Target: Logger {
                let mut events = pending_events.lock().unwrap();
                debug_assert_eq!(paths.len(), path_results.len());
                for (path, path_res) in paths.into_iter().zip(path_results) {
                        if let Err(e) = path_res {
                                if let APIError::MonitorUpdateInProgress = e { continue }
+                               log_error!(logger, "Failed to send along path due to error: {:?}", e);
                                let mut failed_scid = None;
                                if let APIError::ChannelUnavailable { .. } = e {
                                        let scid = path[0].short_channel_id;
@@ -842,7 +857,7 @@ impl OutboundPayments {
        where
                ES::Target: EntropySource,
                NS::Target: NodeSigner,
-               F: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                let payment_id = PaymentId(entropy_source.get_secure_random_bytes());
@@ -856,9 +871,13 @@ impl OutboundPayments {
                }
 
                let route = Route { paths: vec![hops], 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)?;
+               let onion_session_privs = self.add_new_pending_payment(payment_hash,
+                       RecipientOnionFields::spontaneous_empty(), 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) {
+               match self.pay_route_internal(&route, payment_hash, RecipientOnionFields::spontaneous_empty(),
+                       None, payment_id, None, onion_session_privs, node_signer, best_block_height, &send_payment_along_path
+               ) {
                        Ok(()) => Ok((payment_hash, payment_id)),
                        Err(e) => {
                                self.remove_outbound_if_all_failed(payment_id, &e);
@@ -869,14 +888,14 @@ impl OutboundPayments {
 
        #[cfg(test)]
        pub(super) fn test_add_new_pending_payment<ES: Deref>(
-               &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
+               &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
                route: &Route, retry_strategy: Option<Retry>, entropy_source: &ES, best_block_height: u32
        ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
-               self.add_new_pending_payment(payment_hash, payment_secret, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
+               self.add_new_pending_payment(payment_hash, recipient_onion, payment_id, None, route, retry_strategy, None, entropy_source, best_block_height)
        }
 
        pub(super) fn add_new_pending_payment<ES: Deref>(
-               &self, payment_hash: PaymentHash, payment_secret: Option<PaymentSecret>, payment_id: PaymentId,
+               &self, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields, payment_id: PaymentId,
                keysend_preimage: Option<PaymentPreimage>, route: &Route, retry_strategy: Option<Retry>,
                payment_params: Option<PaymentParameters>, entropy_source: &ES, best_block_height: u32
        ) -> Result<Vec<[u8; 32]>, PaymentSendFailure> where ES::Target: EntropySource {
@@ -897,7 +916,7 @@ impl OutboundPayments {
                                        pending_amt_msat: 0,
                                        pending_fee_msat: Some(0),
                                        payment_hash,
-                                       payment_secret,
+                                       payment_secret: recipient_onion.payment_secret,
                                        keysend_preimage,
                                        starting_block_height: best_block_height,
                                        total_msat: route.get_total_amount(),
@@ -913,20 +932,20 @@ impl OutboundPayments {
        }
 
        fn pay_route_internal<NS: Deref, F>(
-               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
                keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
                onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
                send_payment_along_path: &F
        ) -> Result<(), PaymentSendFailure>
        where
                NS::Target: NodeSigner,
-               F: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
                if route.paths.len() < 1 {
                        return Err(PaymentSendFailure::ParameterError(APIError::InvalidRoute{err: "There must be at least one path to send over".to_owned()}));
                }
-               if payment_secret.is_none() && route.paths.len() > 1 {
+               if recipient_onion.payment_secret.is_none() && route.paths.len() > 1 {
                        return Err(PaymentSendFailure::ParameterError(APIError::APIMisuseError{err: "Payment secret is required for multi-path payments".to_owned()}));
                }
                let mut total_value = 0;
@@ -957,7 +976,8 @@ impl OutboundPayments {
                let mut results = Vec::new();
                debug_assert_eq!(route.paths.len(), onion_session_privs.len());
                for (path, session_priv) in route.paths.iter().zip(onion_session_privs.into_iter()) {
-                       let mut path_res = send_payment_along_path(&path, &payment_hash, payment_secret, total_value, cur_height, payment_id, &keysend_preimage, session_priv);
+                       let mut path_res = send_payment_along_path(&path, &payment_hash, recipient_onion.clone(),
+                               total_value, cur_height, payment_id, &keysend_preimage, session_priv);
                        match path_res {
                                Ok(_) => {},
                                Err(APIError::MonitorUpdateInProgress) => {
@@ -1017,17 +1037,17 @@ impl OutboundPayments {
 
        #[cfg(test)]
        pub(super) fn test_send_payment_internal<NS: Deref, F>(
-               &self, route: &Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>,
+               &self, route: &Route, payment_hash: PaymentHash, recipient_onion: RecipientOnionFields,
                keysend_preimage: Option<PaymentPreimage>, payment_id: PaymentId, recv_value_msat: Option<u64>,
                onion_session_privs: Vec<[u8; 32]>, node_signer: &NS, best_block_height: u32,
                send_payment_along_path: F
        ) -> Result<(), PaymentSendFailure>
        where
                NS::Target: NodeSigner,
-               F: Fn(&Vec<RouteHop>, &PaymentHash, &Option<PaymentSecret>, u64, u32, PaymentId,
+               F: Fn(&Vec<RouteHop>, &PaymentHash, RecipientOnionFields, u64, u32, PaymentId,
                        &Option<PaymentPreimage>, [u8; 32]) -> Result<(), APIError>
        {
-               self.pay_route_internal(route, payment_hash, payment_secret, keysend_preimage, payment_id,
+               self.pay_route_internal(route, payment_hash, recipient_onion, keysend_preimage, payment_id,
                        recv_value_msat, onion_session_privs, node_signer, best_block_height,
                        &send_payment_along_path)
                        .map_err(|e| { self.remove_outbound_if_all_failed(payment_id, &e); e })
@@ -1201,15 +1221,21 @@ impl OutboundPayments {
                        }
 
                        if payment_is_probe || !is_retryable_now || !payment_retryable {
-                               let _ = payment.get_mut().mark_abandoned(); // we'll only Err if it's a legacy payment
+                               let reason = if !payment_retryable {
+                                       PaymentFailureReason::RecipientRejected
+                               } else {
+                                       PaymentFailureReason::RetriesExhausted
+                               };
+                               payment.get_mut().mark_abandoned(reason);
                                is_retryable_now = false;
                        }
                        if payment.get().remaining_parts() == 0 {
-                               if payment.get().abandoned() {
+                               if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. }= payment.get() {
                                        if !payment_is_probe {
                                                full_failure_ev = Some(events::Event::PaymentFailed {
                                                        payment_id: *payment_id,
-                                                       payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
+                                                       payment_hash: *payment_hash,
+                                                       reason: *reason,
                                                });
                                        }
                                        payment.remove();
@@ -1267,15 +1293,17 @@ impl OutboundPayments {
        }
 
        pub(super) fn abandon_payment(
-               &self, payment_id: PaymentId, pending_events: &Mutex<Vec<events::Event>>
+               &self, payment_id: PaymentId, reason: PaymentFailureReason, pending_events: &Mutex<Vec<events::Event>>
        ) {
                let mut outbounds = self.pending_outbound_payments.lock().unwrap();
                if let hash_map::Entry::Occupied(mut payment) = outbounds.entry(payment_id) {
-                       if let Ok(()) = payment.get_mut().mark_abandoned() {
+                       payment.get_mut().mark_abandoned(reason);
+                       if let PendingOutboundPayment::Abandoned { payment_hash, reason, .. } = payment.get() {
                                if payment.get().remaining_parts() == 0 {
                                        pending_events.lock().unwrap().push(events::Event::PaymentFailed {
                                                payment_id,
-                                               payment_hash: payment.get().payment_hash().expect("PendingOutboundPayments::RetriesExceeded always has a payment hash set"),
+                                               payment_hash: *payment_hash,
+                                               reason: *reason,
                                        });
                                        payment.remove();
                                }
@@ -1337,6 +1365,7 @@ impl_writeable_tlv_based_enum_upgradable!(PendingOutboundPayment,
        },
        (3, Abandoned) => {
                (0, session_privs, required),
+               (1, reason, option),
                (2, payment_hash, required),
        },
 );
@@ -1346,9 +1375,9 @@ mod tests {
        use bitcoin::network::constants::Network;
        use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
 
-       use crate::events::{Event, PathFailure};
+       use crate::events::{Event, PathFailure, PaymentFailureReason};
        use crate::ln::PaymentHash;
-       use crate::ln::channelmanager::PaymentId;
+       use crate::ln::channelmanager::{PaymentId, RecipientOnionFields};
        use crate::ln::features::{ChannelFeatures, NodeFeatures};
        use crate::ln::msgs::{ErrorAction, LightningError};
        use crate::ln::outbound_payment::{OutboundPayments, Retry, RetryableSendFailure};
@@ -1385,20 +1414,24 @@ mod tests {
                };
                let pending_events = Mutex::new(Vec::new());
                if on_retry {
-                       outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
-                       &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
-                       Some(expired_route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
+                       outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
+                               PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
+                               Some(Retry::Attempts(1)), Some(expired_route_params.payment_params.clone()),
+                               &&keys_manager, 0).unwrap();
                        outbound_payments.retry_payment_internal(
                                PaymentHash([0; 32]), PaymentId([0; 32]), expired_route_params, &&router, vec![],
                                &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
                                &pending_events, &|_, _, _, _, _, _, _, _| Ok(()));
                        let events = pending_events.lock().unwrap();
                        assert_eq!(events.len(), 1);
-                       if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
+                       if let Event::PaymentFailed { ref reason, .. } = events[0] {
+                               assert_eq!(reason.unwrap(), PaymentFailureReason::PaymentExpired);
+                       } else { panic!("Unexpected event"); }
                } else {
                        let err = outbound_payments.send_payment(
-                               PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), expired_route_params,
-                               &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
+                               PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
+                               Retry::Attempts(0), expired_route_params, &&router, vec![], || InFlightHtlcs::new(),
+                               &&keys_manager, &&keys_manager, 0, &&logger,
                                &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
                        if let RetryableSendFailure::PaymentExpired = err { } else { panic!("Unexpected error"); }
                }
@@ -1429,9 +1462,10 @@ mod tests {
 
                let pending_events = Mutex::new(Vec::new());
                if on_retry {
-                       outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), None, PaymentId([0; 32]), None,
-                               &Route { paths: vec![], payment_params: None }, Some(Retry::Attempts(1)),
-                               Some(route_params.payment_params.clone()), &&keys_manager, 0).unwrap();
+                       outbound_payments.add_new_pending_payment(PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(),
+                               PaymentId([0; 32]), None, &Route { paths: vec![], payment_params: None },
+                               Some(Retry::Attempts(1)), Some(route_params.payment_params.clone()),
+                               &&keys_manager, 0).unwrap();
                        outbound_payments.retry_payment_internal(
                                PaymentHash([0; 32]), PaymentId([0; 32]), route_params, &&router, vec![],
                                &|| InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
@@ -1441,8 +1475,9 @@ mod tests {
                        if let Event::PaymentFailed { .. } = events[0] { } else { panic!("Unexpected event"); }
                } else {
                        let err = outbound_payments.send_payment(
-                               PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params,
-                               &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
+                               PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
+                               Retry::Attempts(0), route_params, &&router, vec![], || InFlightHtlcs::new(),
+                               &&keys_manager, &&keys_manager, 0, &&logger,
                                &pending_events, |_, _, _, _, _, _, _, _| Ok(())).unwrap_err();
                        if let RetryableSendFailure::RouteNotFound = err {
                        } else { panic!("Unexpected error"); }
@@ -1489,9 +1524,9 @@ mod tests {
                // PaymentPathFailed event.
                let pending_events = Mutex::new(Vec::new());
                outbound_payments.send_payment(
-                       PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params.clone(),
-                       &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
-                       &pending_events,
+                       PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
+                       Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
+                       &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
                        |_, _, _, _, _, _, _, _| Err(APIError::ChannelUnavailable { err: "test".to_owned() }))
                        .unwrap();
                let mut events = pending_events.lock().unwrap();
@@ -1508,20 +1543,17 @@ mod tests {
 
                // Ensure that a MonitorUpdateInProgress "error" will not result in a PaymentPathFailed event.
                outbound_payments.send_payment(
-                       PaymentHash([0; 32]), &None, PaymentId([0; 32]), Retry::Attempts(0), route_params.clone(),
-                       &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
-                       &pending_events, |_, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress))
-                       .unwrap();
-               {
-                       let events = pending_events.lock().unwrap();
-                       assert_eq!(events.len(), 0);
-               }
+                       PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([0; 32]),
+                       Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
+                       &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
+                       |_, _, _, _, _, _, _, _| Err(APIError::MonitorUpdateInProgress)).unwrap();
+               assert_eq!(pending_events.lock().unwrap().len(), 0);
 
                // Ensure that any other error will result in a PaymentPathFailed event but no blamed scid.
                outbound_payments.send_payment(
-                       PaymentHash([0; 32]), &None, PaymentId([1; 32]), Retry::Attempts(0), route_params.clone(),
-                       &&router, vec![], || InFlightHtlcs::new(), &&keys_manager, &&keys_manager, 0, &&logger,
-                       &pending_events,
+                       PaymentHash([0; 32]), RecipientOnionFields::spontaneous_empty(), PaymentId([1; 32]),
+                       Retry::Attempts(0), route_params.clone(), &&router, vec![], || InFlightHtlcs::new(),
+                       &&keys_manager, &&keys_manager, 0, &&logger, &pending_events,
                        |_, _, _, _, _, _, _, _| Err(APIError::APIMisuseError { err: "test".to_owned() }))
                        .unwrap();
                let events = pending_events.lock().unwrap();