]> git.bitcoin.ninja Git - rust-lightning/blobdiff - lightning/src/routing/router.rs
Effective channel capacity for router and scoring
[rust-lightning] / lightning / src / routing / router.rs
index e49844383bbceee091e9d42b7262416109b2d484..14844171eb866d7debd1731cd87e5c4c1c6ec02b 100644 (file)
@@ -18,7 +18,7 @@ use ln::channelmanager::ChannelDetails;
 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
 use routing::scoring::Score;
-use routing::network_graph::{NetworkGraph, NodeId, RoutingFees};
+use routing::network_graph::{ChannelInfo, DirectedChannelInfo, DirectionalChannelInfo, EffectiveCapacity, NetworkGraph, NodeId, RoutingFees};
 use util::ser::{Writeable, Readable};
 use util::logger::{Level, Logger};
 
@@ -328,11 +328,80 @@ impl cmp::PartialOrd for RouteGraphNode {
        }
 }
 
-struct DummyDirectionalChannelInfo {
-       cltv_expiry_delta: u32,
-       htlc_minimum_msat: u64,
-       htlc_maximum_msat: Option<u64>,
-       fees: RoutingFees,
+/// A wrapper around the various hop representations.
+///
+/// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
+enum CandidateRouteHop<'a> {
+       /// A hop from the payer to the next hop to the payee, where the outbound liquidity is known.
+       FirstHop {
+               details: &'a ChannelDetails,
+       },
+       /// A hop found in the [`NetworkGraph`], where the channel capacity may or may not be known.
+       PublicHop {
+               short_channel_id: u64,
+               channel: &'a ChannelInfo,
+               direction: &'a DirectionalChannelInfo,
+       },
+       /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
+       PrivateHop {
+               hint: &'a RouteHintHop,
+       }
+}
+
+impl<'a> CandidateRouteHop<'a> {
+       fn short_channel_id(&self) -> u64 {
+               match self {
+                       CandidateRouteHop::FirstHop { details } => details.short_channel_id.unwrap(),
+                       CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
+                       CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
+               }
+       }
+
+       fn features(&self) -> ChannelFeatures {
+               match self {
+                       CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
+                       CandidateRouteHop::PublicHop { channel, .. } => channel.features.clone(),
+                       CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
+               }
+       }
+
+       fn cltv_expiry_delta(&self) -> u32 {
+               match self {
+                       CandidateRouteHop::FirstHop { .. } => 0,
+                       CandidateRouteHop::PublicHop { direction, .. } => direction.cltv_expiry_delta as u32,
+                       CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
+               }
+       }
+
+       fn htlc_minimum_msat(&self) -> u64 {
+               match self {
+                       CandidateRouteHop::FirstHop { .. } => 0,
+                       CandidateRouteHop::PublicHop { direction, .. } => direction.htlc_minimum_msat,
+                       CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
+               }
+       }
+
+       fn fees(&self) -> RoutingFees {
+               match self {
+                       CandidateRouteHop::FirstHop { .. } => RoutingFees {
+                               base_msat: 0, proportional_millionths: 0,
+                       },
+                       CandidateRouteHop::PublicHop { direction, .. } => direction.fees,
+                       CandidateRouteHop::PrivateHop { hint } => hint.fees,
+               }
+       }
+
+       fn effective_capacity(&self) -> EffectiveCapacity {
+               match self {
+                       CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
+                               liquidity_msast: details.outbound_capacity_msat,
+                       },
+                       CandidateRouteHop::PublicHop { channel, direction, .. } => {
+                               DirectedChannelInfo::effective_capacity_from_parts(channel, Some(direction))
+                       },
+                       CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
+               }
+       }
 }
 
 /// It's useful to keep track of the hops associated with the fees required to use them,
@@ -340,12 +409,12 @@ struct DummyDirectionalChannelInfo {
 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
 #[derive(Clone, Debug)]
-struct PathBuildingHop<'a> {
+struct PathBuildingHop {
        // The RouteHintHop fields which will eventually be used if this hop is used in a final Route.
        // Note that node_features is calculated separately after our initial graph walk.
        node_id: NodeId,
        short_channel_id: u64,
-       channel_features: &'a ChannelFeatures,
+       channel_features: ChannelFeatures,
        fee_msat: u64,
        cltv_expiry_delta: u32,
 
@@ -390,11 +459,11 @@ struct PathBuildingHop<'a> {
 // Instantiated with a list of hops with correct data in them collected during path finding,
 // an instance of this struct should be further modified only via given methods.
 #[derive(Clone)]
-struct PaymentPath<'a> {
-       hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
+struct PaymentPath {
+       hops: Vec<(PathBuildingHop, NodeFeatures)>,
 }
 
-impl<'a> PaymentPath<'a> {
+impl PaymentPath {
        // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
        fn get_value_msat(&self) -> u64 {
                self.hops.last().unwrap().0.fee_msat
@@ -632,15 +701,6 @@ where L::Target: Logger {
        let network_graph = network.read_only();
        let network_channels = network_graph.channels();
        let network_nodes = network_graph.nodes();
-       let dummy_directional_info = DummyDirectionalChannelInfo { // used for first_hops routes
-               cltv_expiry_delta: 0,
-               htlc_minimum_msat: 0,
-               htlc_maximum_msat: None,
-               fees: RoutingFees {
-                       base_msat: 0,
-                       proportional_millionths: 0,
-               }
-       };
 
        // Allow MPP only if we have a features set from somewhere that indicates the payee supports
        // it. If the payee supports it they're supposed to include it in the invoice, so that should
@@ -659,24 +719,26 @@ where L::Target: Logger {
        // Prepare the data we'll use for payee-to-payer search by
        // inserting first hops suggested by the caller as targets.
        // Our search will then attempt to reach them while traversing from the payee node.
-       let mut first_hop_targets: HashMap<_, Vec<(_, ChannelFeatures, _, NodeFeatures)>> =
+       let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
                HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
        if let Some(hops) = first_hops {
                for chan in hops {
-                       let short_channel_id = chan.short_channel_id.expect("first_hops should be filled in with usable channels, not pending ones");
+                       if chan.short_channel_id.is_none() {
+                               panic!("first_hops should be filled in with usable channels, not pending ones");
+                       }
                        if chan.counterparty.node_id == *our_node_pubkey {
                                return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
                        }
-                       first_hop_targets.entry(NodeId::from_pubkey(&chan.counterparty.node_id)).or_insert(Vec::new())
-                               .push((short_channel_id, chan.counterparty.features.to_context(), chan.outbound_capacity_msat, chan.counterparty.features.to_context()));
+                       first_hop_targets
+                               .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
+                               .or_insert(Vec::new())
+                               .push(chan);
                }
                if first_hop_targets.is_empty() {
                        return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
                }
        }
 
-       let empty_channel_features = ChannelFeatures::empty();
-
        // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
        // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
        // adding duplicate entries when we find a better path to a given node.
@@ -715,13 +777,11 @@ where L::Target: Logger {
        log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee.pubkey, our_node_pubkey, final_value_msat);
 
        macro_rules! add_entry {
-               // Adds entry which goes from $src_node_id to $dest_node_id
-               // over the channel with id $chan_id with fees described in
-               // $directional_info.
+               // 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 channel *after* this one,
                // since that value has to be transferred over this channel.
                // Returns whether this channel caused an update to `targets`.
-               ( $chan_id: expr, $src_node_id: expr, $dest_node_id: expr, $directional_info: expr, $capacity_sats: expr, $chan_features: expr, $next_hops_fee_msat: expr,
+               ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
                   $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr ) => { {
                        // We "return" whether we updated the path at the end, via this:
                        let mut did_add_update_path_to_src_node = false;
@@ -729,28 +789,11 @@ where L::Target: Logger {
                        // practice these cases should be caught earlier:
                        // - for regular channels at channel announcement (TODO)
                        // - for first and last hops early in get_route
-                       if $src_node_id != $dest_node_id.clone() {
-                               let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat.entry($chan_id.clone()).or_insert_with(|| {
-                                       let mut initial_liquidity_available_msat = None;
-                                       if let Some(capacity_sats) = $capacity_sats {
-                                               initial_liquidity_available_msat = Some(capacity_sats * 1000);
-                                       }
-
-                                       if let Some(htlc_maximum_msat) = $directional_info.htlc_maximum_msat {
-                                               if let Some(available_msat) = initial_liquidity_available_msat {
-                                                       initial_liquidity_available_msat = Some(cmp::min(available_msat, htlc_maximum_msat));
-                                               } else {
-                                                       initial_liquidity_available_msat = Some(htlc_maximum_msat);
-                                               }
-                                       }
-
-                                       match initial_liquidity_available_msat {
-                                               Some(available_msat) => available_msat,
-                                               // We assume channels with unknown balance have
-                                               // a capacity of 0.0025 BTC (or 250_000 sats).
-                                               None => 250_000 * 1000
-                                       }
-                               });
+                       if $src_node_id != $dest_node_id {
+                               let short_channel_id = $candidate.short_channel_id();
+                               let available_liquidity_msat = bookkeeped_channels_liquidity_available_msat
+                                       .entry(short_channel_id)
+                                       .or_insert_with(|| $candidate.effective_capacity().as_msat());
 
                                // It is tricky to substract $next_hops_fee_msat from available liquidity here.
                                // It may be misleading because we might later choose to reduce the value transferred
@@ -792,7 +835,7 @@ where L::Target: Logger {
                                                None => unreachable!(),
                                        };
                                        #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
-                                       let over_path_minimum_msat = amount_to_transfer_over_msat >= $directional_info.htlc_minimum_msat &&
+                                       let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
                                                amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
 
                                        // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
@@ -807,16 +850,16 @@ where L::Target: Logger {
                                                // might violate htlc_minimum_msat on the hops which are next along the
                                                // payment path (upstream to the payee). To avoid that, we recompute path
                                                // path fees knowing the final path contribution after constructing it.
-                                               let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $directional_info.fees)
+                                               let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
                                                        .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
-                                                       .map(|fee_msat| cmp::max(fee_msat, $directional_info.htlc_minimum_msat))
+                                                       .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
                                                        .unwrap_or_else(|| u64::max_value());
                                                let hm_entry = dist.entry($src_node_id);
                                                let old_entry = hm_entry.or_insert_with(|| {
-                                                       // If there was previously no known way to access
-                                                       // the source node (recall it goes payee-to-payer) of $chan_id, first add
-                                                       // semi-dummy record just to compute the fees to reach the source node.
-                                                       // This will affect our decision on selecting $chan_id
+                                                       // If there was previously no known way to access the source node
+                                                       // (recall it goes payee-to-payer) of short_channel_id, first add a
+                                                       // semi-dummy record just to compute the fees to reach the source node.
+                                                       // This will affect our decision on selecting short_channel_id
                                                        // as a way to reach the $dest_node_id.
                                                        let mut fee_base_msat = u32::max_value();
                                                        let mut fee_proportional_millionths = u32::max_value();
@@ -827,18 +870,18 @@ where L::Target: Logger {
                                                        PathBuildingHop {
                                                                node_id: $dest_node_id.clone(),
                                                                short_channel_id: 0,
-                                                               channel_features: $chan_features,
+                                                               channel_features: $candidate.features(),
                                                                fee_msat: 0,
                                                                cltv_expiry_delta: 0,
                                                                src_lowest_inbound_fees: RoutingFees {
                                                                        base_msat: fee_base_msat,
                                                                        proportional_millionths: fee_proportional_millionths,
                                                                },
-                                                               channel_fees: $directional_info.fees,
+                                                               channel_fees: $candidate.fees(),
                                                                next_hops_fee_msat: u64::max_value(),
                                                                hop_use_fee_msat: u64::max_value(),
                                                                total_fee_msat: u64::max_value(),
-                                                               htlc_minimum_msat: $directional_info.htlc_minimum_msat,
+                                                               htlc_minimum_msat: $candidate.htlc_minimum_msat(),
                                                                path_htlc_minimum_msat,
                                                                path_penalty_msat: u64::max_value(),
                                                                was_processed: false,
@@ -863,7 +906,7 @@ where L::Target: Logger {
                                                        // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
                                                        // will have the same effective-fee
                                                        if $src_node_id != our_node_id {
-                                                               match compute_fees(amount_to_transfer_over_msat, $directional_info.fees) {
+                                                               match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
                                                                        // max_value means we'll always fail
                                                                        // the old_entry.total_fee_msat > total_fee_msat check
                                                                        None => total_fee_msat = u64::max_value(),
@@ -893,7 +936,7 @@ where L::Target: Logger {
                                                        }
 
                                                        let path_penalty_msat = $next_hops_path_penalty_msat.checked_add(
-                                                               scorer.channel_penalty_msat($chan_id.clone(), amount_to_transfer_over_msat, Some(*available_liquidity_msat),
+                                                               scorer.channel_penalty_msat(short_channel_id, amount_to_transfer_over_msat, *available_liquidity_msat,
                                                                        &$src_node_id, &$dest_node_id)).unwrap_or_else(|| u64::max_value());
                                                        let new_graph_node = RouteGraphNode {
                                                                node_id: $src_node_id,
@@ -904,7 +947,7 @@ where L::Target: Logger {
                                                                path_penalty_msat,
                                                        };
 
-                                                       // Update the way of reaching $src_node_id with the given $chan_id (from $dest_node_id),
+                                                       // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
                                                        // if this way is cheaper than the already known
                                                        // (considering the cost to "reach" this channel from the route destination,
                                                        // the cost of using this channel,
@@ -933,12 +976,12 @@ where L::Target: Logger {
                                                                old_entry.hop_use_fee_msat = hop_use_fee_msat;
                                                                old_entry.total_fee_msat = total_fee_msat;
                                                                old_entry.node_id = $dest_node_id.clone();
-                                                               old_entry.short_channel_id = $chan_id.clone();
-                                                               old_entry.channel_features = $chan_features;
+                                                               old_entry.short_channel_id = short_channel_id;
+                                                               old_entry.channel_features = $candidate.features();
                                                                old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
-                                                               old_entry.cltv_expiry_delta = $directional_info.cltv_expiry_delta as u32;
-                                                               old_entry.channel_fees = $directional_info.fees;
-                                                               old_entry.htlc_minimum_msat = $directional_info.htlc_minimum_msat;
+                                                               old_entry.cltv_expiry_delta = $candidate.cltv_expiry_delta();
+                                                               old_entry.channel_fees = $candidate.fees();
+                                                               old_entry.htlc_minimum_msat = $candidate.htlc_minimum_msat();
                                                                old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
                                                                old_entry.path_penalty_msat = path_penalty_msat;
                                                                #[cfg(any(test, feature = "fuzztarget"))]
@@ -1005,8 +1048,9 @@ where L::Target: Logger {
 
                        if !skip_node {
                                if let Some(first_channels) = first_hop_targets.get(&$node_id) {
-                                       for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
-                                               add_entry!(first_hop, our_node_id, $node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat);
+                                       for details in first_channels {
+                                               let candidate = CandidateRouteHop::FirstHop { details };
+                                               add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat);
                                        }
                                }
 
@@ -1020,21 +1064,19 @@ where L::Target: Logger {
                                        for chan_id in $node.channels.iter() {
                                                let chan = network_channels.get(chan_id).unwrap();
                                                if !chan.features.requires_unknown_bits() {
-                                                       if chan.node_one == $node_id {
-                                                               // ie $node is one, ie next hop in A* is two, via the two_to_one channel
-                                                               if first_hops.is_none() || chan.node_two != our_node_id {
-                                                                       if let Some(two_to_one) = chan.two_to_one.as_ref() {
-                                                                               if two_to_one.enabled {
-                                                                                       add_entry!(chan_id, chan.node_two, chan.node_one, two_to_one, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat);
-                                                                               }
-                                                                       }
-                                                               }
-                                                       } else {
-                                                               if first_hops.is_none() || chan.node_one != our_node_id{
-                                                                       if let Some(one_to_two) = chan.one_to_two.as_ref() {
-                                                                               if one_to_two.enabled {
-                                                                                       add_entry!(chan_id, chan.node_one, chan.node_two, one_to_two, chan.capacity_sats, &chan.features, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat);
-                                                                               }
+                                                       let directed_channel = chan.directed_to(&$node_id);
+                                                       let source = directed_channel.source();
+                                                       let target = directed_channel.target();
+                                                       if first_hops.is_none() || *source != our_node_id {
+                                                               let (channel, direction) = directed_channel.into_parts();
+                                                               if let Some(direction) = direction {
+                                                                       if direction.enabled {
+                                                                               let candidate = CandidateRouteHop::PublicHop {
+                                                                                       short_channel_id: *chan_id,
+                                                                                       channel,
+                                                                                       direction,
+                                                                               };
+                                                                               add_entry!(candidate, *source, *target, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat);
                                                                        }
                                                                }
                                                        }
@@ -1059,9 +1101,10 @@ where L::Target: Logger {
                // If first hop is a private channel and the only way to reach the payee, this is the only
                // place where it could be added.
                if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
-                       for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
-                               let added = add_entry!(first_hop, our_node_id, payee_node_id, dummy_directional_info, Some(outbound_capacity_msat / 1000), features, 0, path_value_msat, 0, 0u64);
-                               log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, first_hop);
+                       for details in first_channels {
+                               let candidate = CandidateRouteHop::FirstHop { details };
+                               let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64);
+                               log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
                        }
                }
 
@@ -1102,39 +1145,26 @@ where L::Target: Logger {
                                let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
 
                                for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
-                                       // BOLT 11 doesn't allow inclusion of features for the last hop hints, which
-                                       // really sucks, cause we're gonna need that eventually.
-                                       let hop_htlc_minimum_msat: u64 = hop.htlc_minimum_msat.unwrap_or(0);
-
-                                       let directional_info = DummyDirectionalChannelInfo {
-                                               cltv_expiry_delta: hop.cltv_expiry_delta as u32,
-                                               htlc_minimum_msat: hop_htlc_minimum_msat,
-                                               htlc_maximum_msat: hop.htlc_maximum_msat,
-                                               fees: hop.fees,
-                                       };
-
-                                       // We want a value of final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR but we
-                                       // need it to increment at each hop by the fee charged at later hops. Further,
-                                       // we need to ensure we round up when we divide to get satoshis.
-                                       let channel_cap_msat = final_value_msat
-                                               .checked_mul(ROUTE_CAPACITY_PROVISION_FACTOR).and_then(|v| v.checked_add(aggregate_next_hops_fee_msat))
-                                               .unwrap_or(u64::max_value());
-                                       let channel_cap_sat = match channel_cap_msat.checked_add(999) {
-                                               None => break, // We overflowed above, just ignore this route hint
-                                               Some(val) => Some(val / 1000),
-                                       };
-
-                                       let src_node_id = NodeId::from_pubkey(&hop.src_node_id);
-                                       let dest_node_id = NodeId::from_pubkey(&prev_hop_id);
+                                       let source = NodeId::from_pubkey(&hop.src_node_id);
+                                       let target = NodeId::from_pubkey(&prev_hop_id);
+                                       let candidate = network_channels
+                                               .get(&hop.short_channel_id)
+                                               .map(|channel| channel.as_directed(&source, &target).into_parts())
+                                               .and_then(|(channel, direction)| {
+                                                       direction.map(|direction|
+                                                               CandidateRouteHop::PublicHop {
+                                                                       short_channel_id: hop.short_channel_id,
+                                                                       channel,
+                                                                       direction,
+                                                               })
+                                               })
+                                               .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
+                                       let capacity_msat = candidate.effective_capacity().as_msat();
                                        aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
-                                               .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, None, &src_node_id, &dest_node_id))
+                                               .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, capacity_msat, &source, &target))
                                                .unwrap_or_else(|| u64::max_value());
 
-                                       // We assume that the recipient only included route hints for routes which had
-                                       // sufficient value to route `final_value_msat`. Note that in the case of "0-value"
-                                       // invoices where the invoice does not specify value this may not be the case, but
-                                       // better to include the hints than not.
-                                       if !add_entry!(hop.short_channel_id, src_node_id, dest_node_id, directional_info, channel_cap_sat, &empty_channel_features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat) {
+                                       if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat) {
                                                // If this hop was not used then there is no use checking the preceding hops
                                                // in the RouteHint. We can break by just searching for a direct channel between
                                                // last checked hop and first_hop_targets
@@ -1143,8 +1173,9 @@ where L::Target: Logger {
 
                                        // Searching for a direct channel between last checked hop and first_hop_targets
                                        if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
-                                               for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
-                                                       add_entry!(first_hop, our_node_id , NodeId::from_pubkey(&prev_hop_id), dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat);
+                                               for details in first_channels {
+                                                       let candidate = CandidateRouteHop::FirstHop { details };
+                                                       add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat);
                                                }
                                        }
 
@@ -1161,6 +1192,7 @@ where L::Target: Logger {
                                                .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
                                        aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
 
+                                       let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
                                        let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
                                        let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
                                                .checked_add(hop_htlc_minimum_msat_inc);
@@ -1177,8 +1209,9 @@ where L::Target: Logger {
                                                // always assumes that the third argument is a node to which we have a
                                                // path.
                                                if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
-                                                       for (ref first_hop, ref features, ref outbound_capacity_msat, _) in first_channels {
-                                                               add_entry!(first_hop, our_node_id , NodeId::from_pubkey(&hop.src_node_id), dummy_directional_info, Some(outbound_capacity_msat / 1000), features, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat);
+                                                       for details in first_channels {
+                                                               let candidate = CandidateRouteHop::FirstHop { details };
+                                                               add_entry!(candidate, our_node_id, NodeId::from_pubkey(&hop.src_node_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat);
                                                        }
                                                }
                                        }
@@ -1212,9 +1245,9 @@ where L::Target: Logger {
                                'path_walk: loop {
                                        let mut features_set = false;
                                        if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
-                                               for (scid, _, _, ref features) in first_channels {
-                                                       if *scid == ordered_hops.last().unwrap().0.short_channel_id {
-                                                               ordered_hops.last_mut().unwrap().1 = features.clone();
+                                               for details in first_channels {
+                                                       if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.short_channel_id {
+                                                               ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
                                                                features_set = true;
                                                                break;
                                                        }
@@ -2814,7 +2847,7 @@ mod tests {
                // If we have a peer in the node map, we'll use their features here since we don't have
                // a way of figuring out their features from the invoice:
                assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
-               assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new());
+               assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
 
                assert_eq!(route.paths[0][4].pubkey, nodes[6]);
                assert_eq!(route.paths[0][4].short_channel_id, 8);
@@ -4661,7 +4694,7 @@ mod tests {
                fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
        }
        impl Score for BadChannelScorer {
-               fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, _target: &NodeId) -> u64 {
+               fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, _target: &NodeId) -> u64 {
                        if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
                }
 
@@ -4679,7 +4712,7 @@ mod tests {
        }
 
        impl Score for BadNodeScorer {
-               fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _chan_amt: Option<u64>, _source: &NodeId, target: &NodeId) -> u64 {
+               fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, target: &NodeId) -> u64 {
                        if *target == self.node_id { u64::max_value() } else { 0 }
                }