Merge pull request #2522 from sr-gi/202308-set-feature
[rust-lightning] / lightning / src / routing / router.rs
index d3539579c50ae16d8a8d92eb806af6364243327d..79d54e22d6755896ee1c4ead6be0804413178a47 100644 (file)
@@ -16,26 +16,26 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use crate::blinded_path::{BlindedHop, BlindedPath};
 use crate::ln::PaymentHash;
 use crate::ln::channelmanager::{ChannelDetails, PaymentId};
-use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
+use crate::ln::features::{Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures};
 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
-use crate::offers::invoice::{BlindedPayInfo, Invoice as Bolt12Invoice};
+use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice};
 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
-use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
+use crate::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp};
 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
 use crate::util::logger::{Level, Logger};
 use crate::util::chacha20::ChaCha20;
 
 use crate::io;
 use crate::prelude::*;
-use crate::sync::{Mutex};
+use crate::sync::Mutex;
 use alloc::collections::BinaryHeap;
 use core::{cmp, fmt};
-use core::ops::{Deref, DerefMut};
+use core::ops::Deref;
 
 /// A [`Router`] implemented using [`find_route`].
-pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> where
+pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Score = Sc>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        network_graph: G,
        logger: L,
@@ -44,9 +44,9 @@ pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref,
        score_params: SP
 }
 
-impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> DefaultRouter<G, L, S, SP, Sc> where
+impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> DefaultRouter<G, L, S, SP, Sc> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Score = Sc>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        /// Creates a new router.
        pub fn new(network_graph: G, logger: L, random_seed_bytes: [u8; 32], scorer: S, score_params: SP) -> Self {
@@ -55,16 +55,16 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Scor
        }
 }
 
-impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> Router for DefaultRouter<G, L, S, SP, Sc> where
+impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> Router for DefaultRouter<G, L, S, SP, Sc> where
        L::Target: Logger,
-       S::Target: for <'a> LockableScore<'a, Score = Sc>,
+       S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
 {
        fn find_route(
                &self,
                payer: &PublicKey,
                params: &RouteParameters,
                first_hops: Option<&[&ChannelDetails]>,
-               inflight_htlcs: &InFlightHtlcs
+               inflight_htlcs: InFlightHtlcs
        ) -> Result<Route, LightningError> {
                let random_seed_bytes = {
                        let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
@@ -73,7 +73,7 @@ impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Sco
                };
                find_route(
                        payer, params, &self.network_graph, first_hops, &*self.logger,
-                       &ScorerAccountingForInFlightHtlcs::new(self.scorer.lock().deref_mut(), inflight_htlcs),
+                       &ScorerAccountingForInFlightHtlcs::new(self.scorer.read_lock(), &inflight_htlcs),
                        &self.score_params,
                        &random_seed_bytes
                )
@@ -82,37 +82,44 @@ impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Sco
 
 /// A trait defining behavior for routing a payment.
 pub trait Router {
-       /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
+       /// Finds a [`Route`] for a payment between the given `payer` and a payee.
+       ///
+       /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
+       /// and [`RouteParameters::final_value_msat`], respectively.
        fn find_route(
                &self, payer: &PublicKey, route_params: &RouteParameters,
-               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
+               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
        ) -> Result<Route, LightningError>;
-       /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values. Includes
-       /// `PaymentHash` and `PaymentId` to be able to correlate the request with a specific payment.
+       /// Finds a [`Route`] for a payment between the given `payer` and a payee.
+       ///
+       /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
+       /// and [`RouteParameters::final_value_msat`], respectively.
+       ///
+       /// Includes a [`PaymentHash`] and a [`PaymentId`] to be able to correlate the request with a specific
+       /// payment.
        fn find_route_with_id(
                &self, payer: &PublicKey, route_params: &RouteParameters,
-               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs,
+               first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs,
                _payment_hash: PaymentHash, _payment_id: PaymentId
        ) -> Result<Route, LightningError> {
                self.find_route(payer, route_params, first_hops, inflight_htlcs)
        }
 }
 
-/// [`Score`] implementation that factors in in-flight HTLC liquidity.
+/// [`ScoreLookUp`] implementation that factors in in-flight HTLC liquidity.
 ///
-/// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
+/// Useful for custom [`Router`] implementations to wrap their [`ScoreLookUp`] on-the-fly when calling
 /// [`find_route`].
 ///
-/// [`Score`]: crate::routing::scoring::Score
-pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score<ScoreParams = SP>, SP: Sized> {
-       scorer: &'a mut S,
+/// [`ScoreLookUp`]: crate::routing::scoring::ScoreLookUp
+pub struct ScorerAccountingForInFlightHtlcs<'a, SP: Sized, Sc: 'a + ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> {
+       scorer: S,
        // Maps a channel's short channel id and its direction to the liquidity used up.
        inflight_htlcs: &'a InFlightHtlcs,
 }
-
-impl<'a, S: Score<ScoreParams = SP>, SP: Sized> ScorerAccountingForInFlightHtlcs<'a, S, SP> {
+impl<'a, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
        /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
-       pub fn new(scorer:  &'a mut S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
+       pub fn new(scorer: S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
                ScorerAccountingForInFlightHtlcs {
                        scorer,
                        inflight_htlcs
@@ -121,12 +128,12 @@ impl<'a, S: Score<ScoreParams = SP>, SP: Sized> ScorerAccountingForInFlightHtlcs
 }
 
 #[cfg(c_bindings)]
-impl<'a, S: Score<ScoreParams = SP>, SP: Sized> Writeable for ScorerAccountingForInFlightHtlcs<'a, S, SP> {
+impl<'a, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> Writeable for ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
 }
 
-impl<'a, S: Score<ScoreParams = SP>, SP: Sized> Score for ScorerAccountingForInFlightHtlcs<'a, S, SP>  {
-       type ScoreParams = S::ScoreParams;
+impl<'a, SP: Sized, Sc: 'a + ScoreLookUp<ScoreParams = SP>, S: Deref<Target = Sc>> ScoreLookUp for ScorerAccountingForInFlightHtlcs<'a, SP, Sc, S> {
+       type ScoreParams = Sc::ScoreParams;
        fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 {
                if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
                        source, target, short_channel_id
@@ -141,22 +148,6 @@ impl<'a, S: Score<ScoreParams = SP>, SP: Sized> Score for ScorerAccountingForInF
                        self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
                }
        }
-
-       fn payment_path_failed(&mut self, path: &Path, short_channel_id: u64) {
-               self.scorer.payment_path_failed(path, short_channel_id)
-       }
-
-       fn payment_path_successful(&mut self, path: &Path) {
-               self.scorer.payment_path_successful(path)
-       }
-
-       fn probe_failed(&mut self, path: &Path, short_channel_id: u64) {
-               self.scorer.probe_failed(path, short_channel_id)
-       }
-
-       fn probe_successful(&mut self, path: &Path) {
-               self.scorer.probe_successful(path)
-       }
 }
 
 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
@@ -271,9 +262,9 @@ impl_writeable_tlv_based!(RouteHop, {
 });
 
 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
-/// their BOLT12 [`Invoice`].
+/// their [`Bolt12Invoice`].
 ///
-/// [`Invoice`]: crate::offers::invoice::Invoice
+/// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct BlindedTail {
        /// The hops of the [`BlindedPath`] provided by the recipient.
@@ -346,11 +337,9 @@ pub struct Route {
        /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
        /// the same.
        pub paths: Vec<Path>,
-       /// The `payment_params` parameter passed to [`find_route`].
-       /// This is used by `ChannelManager` to track information which may be required for retries,
-       /// provided back to you via [`Event::PaymentPathFailed`].
+       /// The `payment_params` parameter passed via [`RouteParameters`] to [`find_route`].
        ///
-       /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
+       /// This is used by `ChannelManager` to track information which may be required for retries.
        pub payment_params: Option<PaymentParameters>,
 }
 
@@ -358,7 +347,7 @@ impl Route {
        /// Returns the total amount of fees paid on this [`Route`].
        ///
        /// This doesn't include any extra payment made to the recipient, which can happen in excess of
-       /// the amount passed to [`find_route`]'s `params.final_value_msat`.
+       /// the amount passed to [`find_route`]'s `route_params.final_value_msat`.
        pub fn get_total_fees(&self) -> u64 {
                self.paths.iter().map(|path| path.fee_msat()).sum()
        }
@@ -419,7 +408,7 @@ impl Readable for Route {
                                cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
                        paths.push(Path { hops, blinded_tail: None });
                }
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
                        (2, blinded_tails, optional_vec),
                });
@@ -436,10 +425,7 @@ impl Readable for Route {
 
 /// Parameters needed to find a [`Route`].
 ///
-/// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
-/// [`Event::PaymentPathFailed`].
-///
-/// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
+/// Passed to [`find_route`] and [`build_route_from_hops`].
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct RouteParameters {
        /// The parameters of the failed payment path.
@@ -464,7 +450,7 @@ impl Writeable for RouteParameters {
 
 impl Readable for RouteParameters {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payment_params, (required: ReadableArgs, 0)),
                        (2, final_value_msat, required),
                        (4, final_cltv_delta, option),
@@ -572,7 +558,7 @@ impl Writeable for PaymentParameters {
 
 impl ReadableArgs<u32> for PaymentParameters {
        fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
-               _init_and_read_tlv_fields!(reader, {
+               _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payee_pubkey, option),
                        (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
                        (2, features, (option: ReadableArgs, payee_pubkey.is_some())),
@@ -640,7 +626,7 @@ impl PaymentParameters {
        /// [`RecipientOnionFields::secret_only`]: crate::ln::channelmanager::RecipientOnionFields::secret_only
        pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32, allow_mpp: bool) -> Self {
                Self::from_node_id(payee_pubkey, final_cltv_expiry_delta)
-                       .with_bolt11_features(InvoiceFeatures::for_keysend(allow_mpp))
+                       .with_bolt11_features(Bolt11InvoiceFeatures::for_keysend(allow_mpp))
                        .expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
        }
 
@@ -649,11 +635,12 @@ impl PaymentParameters {
        /// [`PaymentParameters::expiry_time`].
        pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
                Self::blinded(invoice.payment_paths().to_vec())
-                       .with_bolt12_features(invoice.features().clone()).unwrap()
+                       .with_bolt12_features(invoice.invoice_features().clone()).unwrap()
                        .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
        }
 
-       fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
+       /// Creates parameters for paying to a blinded payee from the provided blinded route hints.
+       pub fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
                Self {
                        payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
                        expiry_time: None,
@@ -680,7 +667,7 @@ impl PaymentParameters {
        /// [`PaymentParameters::from_bolt12_invoice`].
        ///
        /// This is not exported to bindings users since bindings don't support move semantics
-       pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
+       pub fn with_bolt11_features(self, features: Bolt11InvoiceFeatures) -> Result<Self, ()> {
                match self.payee {
                        Payee::Blinded { .. } => Err(()),
                        Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
@@ -766,7 +753,7 @@ pub enum Payee {
                /// does not contain any features.
                ///
                /// [`for_keysend`]: PaymentParameters::for_keysend
-               features: Option<InvoiceFeatures>,
+               features: Option<Bolt11InvoiceFeatures>,
                /// The minimum CLTV delta at the end of the route. This value must not be zero.
                final_cltv_expiry_delta: u32,
        },
@@ -819,11 +806,11 @@ impl Payee {
 }
 
 enum FeaturesRef<'a> {
-       Bolt11(&'a InvoiceFeatures),
+       Bolt11(&'a Bolt11InvoiceFeatures),
        Bolt12(&'a Bolt12InvoiceFeatures),
 }
 enum Features {
-       Bolt11(InvoiceFeatures),
+       Bolt11(Bolt11InvoiceFeatures),
        Bolt12(Bolt12InvoiceFeatures),
 }
 
@@ -834,7 +821,7 @@ impl Features {
                        _ => None,
                }
        }
-       fn bolt11(self) -> Option<InvoiceFeatures> {
+       fn bolt11(self) -> Option<Bolt11InvoiceFeatures> {
                match self {
                        Self::Bolt11(f) => Some(f),
                        _ => None,
@@ -1330,6 +1317,14 @@ impl<'a> fmt::Display for LoggedCandidateHop<'a> {
                                " and blinding point ".fmt(f)?;
                                hint.1.blinding_point.fmt(f)
                        },
+                       CandidateRouteHop::FirstHop { .. } => {
+                               "first hop with SCID ".fmt(f)?;
+                               self.0.short_channel_id().unwrap().fmt(f)
+                       },
+                       CandidateRouteHop::PrivateHop { .. } => {
+                               "route hint with SCID ".fmt(f)?;
+                               self.0.short_channel_id().unwrap().fmt(f)
+                       },
                        _ => {
                                "SCID ".fmt(f)?;
                                self.0.short_channel_id().unwrap().fmt(f)
@@ -1375,10 +1370,12 @@ fn sort_first_hop_channels(
 
 /// Finds a route from us (payer) to the given target node (payee).
 ///
-/// If the payee provided features in their invoice, they should be provided via `params.payee`.
+/// If the payee provided features in their invoice, they should be provided via the `payee` field
+/// in the given [`RouteParameters::payment_params`].
 /// Without this, MPP will only be used if the payee's features are available in the network graph.
 ///
-/// Private routing paths between a public node and the target may be included in `params.payee`.
+/// Private routing paths between a public node and the target may be included in the `payee` field
+/// of [`RouteParameters::payment_params`].
 ///
 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
@@ -1388,21 +1385,15 @@ fn sort_first_hop_channels(
 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
 ///
-/// # Note
-///
-/// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
-/// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
-/// function.
-///
 /// # Panics
 ///
-/// Panics if first_hops contains channels without short_channel_ids;
+/// Panics if first_hops contains channels without `short_channel_id`s;
 /// [`ChannelManager::list_usable_channels`] will never include such channels.
 ///
 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
-pub fn find_route<L: Deref, GL: Deref, S: Score>(
+pub fn find_route<L: Deref, GL: Deref, S: ScoreLookUp>(
        our_node_pubkey: &PublicKey, route_params: &RouteParameters,
        network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
        scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
@@ -1416,7 +1407,7 @@ where L::Target: Logger, GL::Target: Logger {
        Ok(route)
 }
 
-pub(crate) fn get_route<L: Deref, S: Score>(
+pub(crate) fn get_route<L: Deref, S: ScoreLookUp>(
        our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
        first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, logger: L, scorer: &S, score_params: &S::ScoreParams,
        _random_seed_bytes: &[u8; 32]
@@ -1641,6 +1632,12 @@ where L::Target: Logger {
        log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
                LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
 
+       // Remember how many candidates we ignored to allow for some logging afterwards.
+       let mut num_ignored_value_contribution = 0;
+       let mut num_ignored_path_length_limit = 0;
+       let mut num_ignored_cltv_delta_limit = 0;
+       let mut num_ignored_previously_failed = 0;
+
        macro_rules! add_entry {
                // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
                // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
@@ -1715,13 +1712,37 @@ where L::Target: Logger {
                                        let payment_failed_on_this_channel = scid_opt.map_or(false,
                                                |scid| payment_params.previously_failed_channels.contains(&scid));
 
+                                       let should_log_candidate = match $candidate {
+                                               CandidateRouteHop::FirstHop { .. } => true,
+                                               CandidateRouteHop::PrivateHop { .. } => true,
+                                               CandidateRouteHop::Blinded { .. } => true,
+                                               _ => false,
+                                       };
+
                                        // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
                                        // bother considering this channel. If retrying with recommended_value_msat may
                                        // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
                                        // around again with a higher amount.
-                                       if !contributes_sufficient_value || exceeds_max_path_length ||
-                                               exceeds_cltv_delta_limit || payment_failed_on_this_channel {
-                                               // Path isn't useful, ignore it and move on.
+                                       if !contributes_sufficient_value {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to insufficient value contribution.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_value_contribution += 1;
+                                       } else if exceeds_max_path_length {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to exceeding maximum path length limit.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_path_length_limit += 1;
+                                       } else if exceeds_cltv_delta_limit {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to exceeding CLTV delta limit.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_cltv_delta_limit += 1;
+                                       } else if payment_failed_on_this_channel {
+                                               if should_log_candidate {
+                                                       log_trace!(logger, "Ignoring {} due to a failed previous payment attempt.", LoggedCandidateHop(&$candidate));
+                                               }
+                                               num_ignored_previously_failed += 1;
                                        } else if may_overpay_to_meet_path_minimum_msat {
                                                hit_minimum_limit = true;
                                        } else if over_path_minimum_msat {
@@ -1999,8 +2020,14 @@ where L::Target: Logger {
                                        our_node_pubkey);
                                for details in first_channels {
                                        let first_hop_candidate = CandidateRouteHop::FirstHop { details };
-                                       add_entry!(first_hop_candidate, our_node_id, intro_node_id, 0, path_contribution_msat, 0,
-                                               0_u64, 0, 0);
+                                       let blinded_path_fee = match compute_fees(path_contribution_msat, candidate.fees()) {
+                                               Some(fee) => fee,
+                                               None => continue
+                                       };
+                                       add_entry!(first_hop_candidate, our_node_id, intro_node_id, blinded_path_fee,
+                                               path_contribution_msat, candidate.htlc_minimum_msat(), 0_u64,
+                                               candidate.cltv_expiry_delta(),
+                                               candidate.blinded_path().map_or(1, |bp| bp.blinded_hops.len() as u8));
                                }
                        }
                }
@@ -2323,6 +2350,12 @@ where L::Target: Logger {
                }
        }
 
+       let num_ignored_total = num_ignored_value_contribution + num_ignored_path_length_limit +
+               num_ignored_cltv_delta_limit + num_ignored_previously_failed;
+       if num_ignored_total > 0 {
+               log_trace!(logger, "Ignored {} candidate hops due to insufficient value contribution, {} due to path length limit, {} due to CLTV delta limit, {} due to previous payment failure. Total: {} ignored candidates.", num_ignored_value_contribution, num_ignored_path_length_limit, num_ignored_cltv_delta_limit, num_ignored_previously_failed, num_ignored_total);
+       }
+
        // Step (5).
        if payment_paths.len() == 0 {
                return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
@@ -2570,7 +2603,7 @@ fn build_route_from_hops_internal<L: Deref>(
                hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
        }
 
-       impl Score for HopScorer {
+       impl ScoreLookUp for HopScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
                        _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
@@ -2588,14 +2621,6 @@ fn build_route_from_hops_internal<L: Deref>(
                        }
                        u64::max_value()
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-
-               fn payment_path_successful(&mut self, _path: &Path) {}
-
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        impl<'a> Writeable for HopScorer {
@@ -2629,10 +2654,11 @@ mod tests {
        use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
                BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
                DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
-       use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
+       use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, ScoreLookUp, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
        use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
        use crate::chain::transaction::OutPoint;
        use crate::sign::EntropySource;
+       use crate::ln::ChannelId;
        use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, ChannelFeatures, InitFeatures, NodeFeatures};
        use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
        use crate::ln::channelmanager;
@@ -2665,7 +2691,7 @@ mod tests {
        fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
                        features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
                channelmanager::ChannelDetails {
-                       channel_id: [0; 32],
+                       channel_id: ChannelId::new_zero(),
                        counterparty: channelmanager::ChannelCounterparty {
                                features,
                                node_id,
@@ -2681,7 +2707,6 @@ mod tests {
                        inbound_scid_alias: None,
                        channel_value_satoshis: 0,
                        user_channel_id: 0,
-                       balance_msat: 0,
                        outbound_capacity_msat,
                        next_outbound_htlc_limit_msat: outbound_capacity_msat,
                        next_outbound_htlc_minimum_msat: 0,
@@ -3854,7 +3879,7 @@ mod tests {
        fn available_amount_while_routing_test() {
                // Tests whether we choose the correct available channel amount while routing.
 
-               let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
+               let (secp_ctx, network_graph, gossip_sync, chain_monitor, logger) = build_graph();
                let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
                let scorer = ln_test_utils::TestScorer::new();
                let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
@@ -5677,16 +5702,11 @@ mod tests {
        impl Writeable for BadChannelScorer {
                fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
        }
-       impl Score for BadChannelScorer {
+       impl ScoreLookUp for BadChannelScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
                        if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn payment_path_successful(&mut self, _path: &Path) {}
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        struct BadNodeScorer {
@@ -5698,16 +5718,11 @@ mod tests {
                fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
        }
 
-       impl Score for BadNodeScorer {
+       impl ScoreLookUp for BadNodeScorer {
                type ScoreParams = ();
                fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
                        if *target == self.node_id { u64::max_value() } else { 0 }
                }
-
-               fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn payment_path_successful(&mut self, _path: &Path) {}
-               fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
-               fn probe_successful(&mut self, _path: &Path) {}
        }
 
        #[test]
@@ -6104,7 +6119,7 @@ mod tests {
 
                let params = ProbabilisticScoringFeeParameters::default();
                let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
-               let features = super::InvoiceFeatures::empty();
+               let features = super::Bolt11InvoiceFeatures::empty();
 
                super::bench_utils::generate_test_routes(&graph, &mut scorer, &params, features, random_init_seed(), 0, 2);
        }
@@ -6667,6 +6682,159 @@ mod tests {
                }
                assert_eq!(total_amount_paid_msat, 100_000);
        }
+
+       #[test]
+       fn direct_to_intro_node() {
+               // This previously caused a debug panic in the router when asserting
+               // `used_liquidity_msat <= hop_max_msat`, because when adding first_hop<>blinded_route_hint
+               // direct channels we failed to account for the fee charged for use of the blinded path.
+
+               // Build a graph:
+               // node0 -1(1)2 - node1
+               // such that there isn't enough liquidity to reach node1, but the router thinks there is if it
+               // doesn't account for the blinded path fee.
+
+               let secp_ctx = Secp256k1::new();
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+
+               let amt_msat = 10_000_000;
+               let (_, _, privkeys, nodes) = get_nodes(&secp_ctx);
+               add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[1],
+                       ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
+               update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
+                       chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+                       short_channel_id: 1,
+                       timestamp: 1,
+                       flags: 0,
+                       cltv_expiry_delta: 42,
+                       htlc_minimum_msat: 1_000,
+                       htlc_maximum_msat: 10_000_000,
+                       fee_base_msat: 800,
+                       fee_proportional_millionths: 0,
+                       excess_data: Vec::new()
+               });
+               update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
+                       chain_hash: genesis_block(Network::Testnet).header.block_hash(),
+                       short_channel_id: 1,
+                       timestamp: 1,
+                       flags: 1,
+                       cltv_expiry_delta: 42,
+                       htlc_minimum_msat: 1_000,
+                       htlc_maximum_msat: 10_000_000,
+                       fee_base_msat: 800,
+                       fee_proportional_millionths: 0,
+                       excess_data: Vec::new()
+               });
+               let first_hops = vec![
+                       get_channel_details(Some(1), nodes[1], InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
+
+               let blinded_path = BlindedPath {
+                       introduction_node_id: nodes[1],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 1000,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 1000,
+                       htlc_maximum_msat: MAX_VALUE_MSAT,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let blinded_hints = vec![(blinded_payinfo.clone(), blinded_path)];
+
+               let payment_params = PaymentParameters::blinded(blinded_hints.clone());
+
+               let netgraph = network_graph.read_only();
+               if let Err(LightningError { err, .. }) = get_route(&nodes[0], &payment_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
+                       &random_seed_bytes) {
+                       assert_eq!(err, "Failed to find a path to the given destination");
+               } else { panic!("Expected error") }
+
+               // Sending an exact amount accounting for the blinded path fee works.
+               let amt_minus_blinded_path_fee = amt_msat - blinded_payinfo.fee_base_msat as u64;
+               let route = get_route(&nodes[0], &payment_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), amt_minus_blinded_path_fee,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
+               assert_eq!(route.get_total_amount(), amt_minus_blinded_path_fee);
+       }
+
+       #[test]
+       fn direct_to_matching_intro_nodes() {
+               // This previously caused us to enter `unreachable` code in the following situation:
+               // 1. We add a route candidate for intro_node contributing a high amount
+               // 2. We add a first_hop<>intro_node route candidate for the same high amount
+               // 3. We see a cheaper blinded route hint for the same intro node but a much lower contribution
+               //    amount, and update our route candidate for intro_node for the lower amount
+               // 4. We then attempt to update the aforementioned first_hop<>intro_node route candidate for the
+               //    lower contribution amount, but fail (this was previously caused by failure to account for
+               //    blinded path fees when adding first_hop<>intro_node candidates)
+               // 5. We go to construct the path from these route candidates and our first_hop<>intro_node
+               //    candidate still thinks its path is contributing the original higher amount. This caused us
+               //    to hit an `unreachable` overflow when calculating the cheaper intro_node fees over the
+               //    larger amount
+               let secp_ctx = Secp256k1::new();
+               let logger = Arc::new(ln_test_utils::TestLogger::new());
+               let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
+               let scorer = ln_test_utils::TestScorer::new();
+               let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
+               let random_seed_bytes = keys_manager.get_secure_random_bytes();
+               let config = UserConfig::default();
+
+               // Values are taken from the fuzz input that uncovered this panic.
+               let amt_msat = 21_7020_5185_1403_2640;
+               let (_, _, _, nodes) = get_nodes(&secp_ctx);
+               let first_hops = vec![
+                       get_channel_details(Some(1), nodes[1], channelmanager::provided_init_features(&config),
+                               18446744073709551615)];
+
+               let blinded_path = BlindedPath {
+                       introduction_node_id: nodes[1],
+                       blinding_point: ln_test_utils::pubkey(42),
+                       blinded_hops: vec![
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
+                               BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
+                       ],
+               };
+               let blinded_payinfo = BlindedPayInfo {
+                       fee_base_msat: 5046_2720,
+                       fee_proportional_millionths: 0,
+                       htlc_minimum_msat: 4503_5996_2737_0496,
+                       htlc_maximum_msat: 45_0359_9627_3704_9600,
+                       cltv_expiry_delta: 0,
+                       features: BlindedHopFeatures::empty(),
+               };
+               let mut blinded_hints = vec![
+                       (blinded_payinfo.clone(), blinded_path.clone()),
+                       (blinded_payinfo.clone(), blinded_path.clone()),
+               ];
+               blinded_hints[1].0.fee_base_msat = 419_4304;
+               blinded_hints[1].0.fee_proportional_millionths = 257;
+               blinded_hints[1].0.htlc_minimum_msat = 280_8908_6115_8400;
+               blinded_hints[1].0.htlc_maximum_msat = 2_8089_0861_1584_0000;
+               blinded_hints[1].0.cltv_expiry_delta = 0;
+
+               let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
+               let payment_params = PaymentParameters::blinded(blinded_hints.clone())
+                       .with_bolt12_features(bolt12_features.clone()).unwrap();
+
+               let netgraph = network_graph.read_only();
+               let route = get_route(&nodes[0], &payment_params, &netgraph,
+                       Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat,
+                       Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
+               assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
+               assert_eq!(route.get_total_amount(), amt_msat);
+       }
 }
 
 #[cfg(all(any(test, ldk_bench), not(feature = "no-std")))]
@@ -6678,9 +6846,11 @@ pub(crate) mod bench_utils {
        use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
 
        use crate::chain::transaction::OutPoint;
+       use crate::routing::scoring::ScoreUpdate;
        use crate::sign::{EntropySource, KeysManager};
+       use crate::ln::ChannelId;
        use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
-       use crate::ln::features::InvoiceFeatures;
+       use crate::ln::features::Bolt11InvoiceFeatures;
        use crate::routing::gossip::NetworkGraph;
        use crate::util::config::UserConfig;
        use crate::util::ser::ReadableArgs;
@@ -6732,7 +6902,7 @@ pub(crate) mod bench_utils {
        #[inline]
        pub(crate) fn first_hop(node_id: PublicKey) -> ChannelDetails {
                ChannelDetails {
-                       channel_id: [0; 32],
+                       channel_id: ChannelId::new_zero(),
                        counterparty: ChannelCounterparty {
                                features: channelmanager::provided_init_features(&UserConfig::default()),
                                node_id,
@@ -6750,7 +6920,6 @@ pub(crate) mod bench_utils {
                        outbound_scid_alias: None,
                        channel_value_satoshis: 10_000_000_000,
                        user_channel_id: 0,
-                       balance_msat: 10_000_000_000,
                        outbound_capacity_msat: 10_000_000_000,
                        next_outbound_htlc_minimum_msat: 0,
                        next_outbound_htlc_limit_msat: 10_000_000_000,
@@ -6771,8 +6940,8 @@ pub(crate) mod bench_utils {
                }
        }
 
-       pub(crate) fn generate_test_routes<S: Score>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
-               score_params: &S::ScoreParams, features: InvoiceFeatures, mut seed: u64,
+       pub(crate) fn generate_test_routes<S: ScoreLookUp + ScoreUpdate>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
+               score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, mut seed: u64,
                starting_amount: u64, route_count: usize,
        ) -> Vec<(ChannelDetails, PaymentParameters, u64)> {
                let payer = payer_pubkey();
@@ -6797,7 +6966,7 @@ pub(crate) mod bench_utils {
                                let amt = starting_amount + seed % 1_000_000;
                                let path_exists =
                                        get_route(&payer, &params, &graph.read_only(), Some(&[&first_hop]),
-                                               amt, &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok();
+                                               amt, &TestLogger::new(), scorer, score_params, &random_seed_bytes).is_ok();
                                if path_exists {
                                        // ...and seed the scorer with success and failure data...
                                        seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
@@ -6811,7 +6980,7 @@ pub(crate) mod bench_utils {
                                                        .with_bolt11_features(mpp_features).unwrap();
 
                                                let route_res = get_route(&payer, &params, &graph.read_only(),
-                                                       Some(&[&first_hop]), score_amt, &TestLogger::new(), &scorer,
+                                                       Some(&[&first_hop]), score_amt, &TestLogger::new(), scorer,
                                                        score_params, &random_seed_bytes);
                                                if let Ok(route) = route_res {
                                                        for path in route.paths {
@@ -6840,7 +7009,7 @@ pub(crate) mod bench_utils {
                // requires a too-high CLTV delta.
                route_endpoints.retain(|(first_hop, params, amt)| {
                        get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
-                               &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok()
+                               &TestLogger::new(), scorer, score_params, &random_seed_bytes).is_ok()
                });
                route_endpoints.truncate(route_count);
                assert_eq!(route_endpoints.len(), route_count);
@@ -6851,9 +7020,10 @@ pub(crate) mod bench_utils {
 #[cfg(ldk_bench)]
 pub mod benches {
        use super::*;
+       use crate::routing::scoring::{ScoreUpdate, ScoreLookUp};
        use crate::sign::{EntropySource, KeysManager};
        use crate::ln::channelmanager;
-       use crate::ln::features::InvoiceFeatures;
+       use crate::ln::features::Bolt11InvoiceFeatures;
        use crate::routing::gossip::NetworkGraph;
        use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
        use crate::util::config::UserConfig;
@@ -6871,7 +7041,7 @@ pub mod benches {
                let logger = TestLogger::new();
                let network_graph = bench_utils::read_network_graph(&logger).unwrap();
                let scorer = FixedPenaltyScorer::with_penalty(0);
-               generate_routes(bench, &network_graph, scorer, &(), InvoiceFeatures::empty(), 0,
+               generate_routes(bench, &network_graph, scorer, &(), Bolt11InvoiceFeatures::empty(), 0,
                        "generate_routes_with_zero_penalty_scorer");
        }
 
@@ -6889,7 +7059,7 @@ pub mod benches {
                let network_graph = bench_utils::read_network_graph(&logger).unwrap();
                let params = ProbabilisticScoringFeeParameters::default();
                let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
-               generate_routes(bench, &network_graph, scorer, &params, InvoiceFeatures::empty(), 0,
+               generate_routes(bench, &network_graph, scorer, &params, Bolt11InvoiceFeatures::empty(), 0,
                        "generate_routes_with_probabilistic_scorer");
        }
 
@@ -6913,9 +7083,9 @@ pub mod benches {
                        "generate_large_mpp_routes_with_probabilistic_scorer");
        }
 
-       fn generate_routes<S: Score>(
+       fn generate_routes<S: ScoreLookUp + ScoreUpdate>(
                bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, mut scorer: S,
-               score_params: &S::ScoreParams, features: InvoiceFeatures, starting_amount: u64,
+               score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, starting_amount: u64,
                bench_name: &'static str,
        ) {
                let payer = bench_utils::payer_pubkey();