X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Frouting%2Frouter.rs;h=277661862e3361d72a3b3b44975a928422a87db9;hb=refs%2Fheads%2F2024-01-om-direct-export;hp=2d8dd0d67e97a553ac547e232d31cedadd1c507d;hpb=6b43153861c4f8dd1f44da737ad0b06eab8659e7;p=rust-lightning diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs index 2d8dd0d6..27766186 100644 --- a/lightning/src/routing/router.rs +++ b/lightning/src/routing/router.rs @@ -9,18 +9,21 @@ //! The router finds paths within a [`NetworkGraph`] for a payment. -use bitcoin::secp256k1::PublicKey; +use bitcoin::secp256k1::{PublicKey, Secp256k1, self}; use bitcoin::hashes::Hash; use bitcoin::hashes::sha256::Hash as Sha256; use crate::blinded_path::{BlindedHop, BlindedPath}; +use crate::blinded_path::payment::{ForwardNode, ForwardTlvs, PaymentConstraints, PaymentRelay, ReceiveTlvs}; use crate::ln::PaymentHash; use crate::ln::channelmanager::{ChannelDetails, PaymentId}; -use crate::ln::features::{Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures}; +use crate::ln::features::{BlindedHopFeatures, Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures}; use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT}; use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice}; +use crate::onion_message::messenger::{DefaultMessageRouter, Destination, MessageRouter, OnionMessagePath}; use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees}; use crate::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp}; +use crate::sign::EntropySource; use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer}; use crate::util::logger::{Level, Logger}; use crate::util::chacha20::ChaCha20; @@ -33,7 +36,7 @@ use core::{cmp, fmt}; use core::ops::Deref; /// A [`Router`] implemented using [`find_route`]. -pub struct DefaultRouter>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> where +pub struct DefaultRouter> + Clone, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> where L::Target: Logger, S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>, { @@ -41,21 +44,23 @@ pub struct DefaultRouter>, L: Deref, S: Deref, logger: L, random_seed_bytes: Mutex<[u8; 32]>, scorer: S, - score_params: SP + score_params: SP, + message_router: DefaultMessageRouter, } -impl>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> DefaultRouter where +impl> + Clone, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> DefaultRouter where L::Target: Logger, 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 { let random_seed_bytes = Mutex::new(random_seed_bytes); - Self { network_graph, logger, random_seed_bytes, scorer, score_params } + let message_router = DefaultMessageRouter::new(network_graph.clone()); + Self { network_graph, logger, random_seed_bytes, scorer, score_params, message_router } } } -impl< G: Deref>, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> Router for DefaultRouter where +impl> + Clone, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> Router for DefaultRouter where L::Target: Logger, S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>, { @@ -78,10 +83,109 @@ impl< G: Deref>, L: Deref, S: Deref, SP: Sized, Sc: Sco &random_seed_bytes ) } + + fn create_blinded_payment_paths< + ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification + >( + &self, recipient: PublicKey, first_hops: Vec, tlvs: ReceiveTlvs, + amount_msats: u64, entropy_source: &ES, secp_ctx: &Secp256k1 + ) -> Result, ()> { + // Limit the number of blinded paths that are computed. + const MAX_PAYMENT_PATHS: usize = 3; + + // Ensure peers have at least three channels so that it is more difficult to infer the + // recipient's node_id. + const MIN_PEER_CHANNELS: usize = 3; + + let network_graph = self.network_graph.deref().read_only(); + let paths = first_hops.into_iter() + .filter(|details| details.counterparty.features.supports_route_blinding()) + .filter(|details| amount_msats <= details.inbound_capacity_msat) + .filter(|details| amount_msats >= details.inbound_htlc_minimum_msat.unwrap_or(0)) + .filter(|details| amount_msats <= details.inbound_htlc_maximum_msat.unwrap_or(u64::MAX)) + .filter(|details| network_graph + .node(&NodeId::from_pubkey(&details.counterparty.node_id)) + .map(|node_info| node_info.channels.len() >= MIN_PEER_CHANNELS) + .unwrap_or(false) + ) + .filter_map(|details| { + let short_channel_id = match details.get_inbound_payment_scid() { + Some(short_channel_id) => short_channel_id, + None => return None, + }; + let payment_relay: PaymentRelay = match details.counterparty.forwarding_info { + Some(forwarding_info) => forwarding_info.into(), + None => return None, + }; + + // Avoid exposing esoteric CLTV expiry deltas + let cltv_expiry_delta = match payment_relay.cltv_expiry_delta { + 0..=40 => 40u32, + 41..=80 => 80u32, + 81..=144 => 144u32, + 145..=216 => 216u32, + _ => return None, + }; + + let payment_constraints = PaymentConstraints { + max_cltv_expiry: tlvs.payment_constraints.max_cltv_expiry + cltv_expiry_delta, + htlc_minimum_msat: details.inbound_htlc_minimum_msat.unwrap_or(0), + }; + Some(ForwardNode { + tlvs: ForwardTlvs { + short_channel_id, + payment_relay, + payment_constraints, + features: BlindedHopFeatures::empty(), + }, + node_id: details.counterparty.node_id, + htlc_maximum_msat: details.inbound_htlc_maximum_msat.unwrap_or(u64::MAX), + }) + }) + .map(|forward_node| { + BlindedPath::new_for_payment( + &[forward_node], recipient, tlvs.clone(), u64::MAX, entropy_source, secp_ctx + ) + }) + .take(MAX_PAYMENT_PATHS) + .collect::, _>>(); + + match paths { + Ok(paths) if !paths.is_empty() => Ok(paths), + _ => { + if network_graph.nodes().contains_key(&NodeId::from_pubkey(&recipient)) { + BlindedPath::one_hop_for_payment(recipient, tlvs, entropy_source, secp_ctx) + .map(|path| vec![path]) + } else { + Err(()) + } + }, + } + } +} + +impl< G: Deref> + Clone, L: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp> MessageRouter for DefaultRouter where + L::Target: Logger, + S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>, +{ + fn find_path( + &self, sender: PublicKey, peers: Vec, destination: Destination + ) -> Result { + self.message_router.find_path(sender, peers, destination) + } + + fn create_blinded_paths< + ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification + >( + &self, recipient: PublicKey, peers: Vec, entropy_source: &ES, + secp_ctx: &Secp256k1 + ) -> Result, ()> { + self.message_router.create_blinded_paths(recipient, peers, entropy_source, secp_ctx) + } } /// A trait defining behavior for routing a payment. -pub trait Router { +pub trait Router: MessageRouter { /// 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`] @@ -105,6 +209,16 @@ pub trait Router { ) -> Result { self.find_route(payer, route_params, first_hops, inflight_htlcs) } + + /// Creates [`BlindedPath`]s for payment to the `recipient` node. The channels in `first_hops` + /// are assumed to be with the `recipient`'s peers. The payment secret and any constraints are + /// given in `tlvs`. + fn create_blinded_payment_paths< + ES: EntropySource + ?Sized, T: secp256k1::Signing + secp256k1::Verification + >( + &self, recipient: PublicKey, first_hops: Vec, tlvs: ReceiveTlvs, + amount_msats: u64, entropy_source: &ES, secp_ctx: &Secp256k1 + ) -> Result, ()>; } /// [`ScoreLookUp`] implementation that factors in in-flight HTLC liquidity. @@ -130,18 +244,27 @@ impl<'a, S: Deref> ScorerAccountingForInFlightHtlcs<'a, S> where S::Target: Scor impl<'a, S: Deref> ScoreLookUp for ScorerAccountingForInFlightHtlcs<'a, S> where S::Target: ScoreLookUp { type ScoreParams = ::ScoreParams; - fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 { + fn channel_penalty_msat(&self, candidate: &CandidateRouteHop, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 { + let target = match candidate.target() { + Some(target) => target, + None => return self.scorer.channel_penalty_msat(candidate, usage, score_params), + }; + let short_channel_id = match candidate.short_channel_id() { + Some(short_channel_id) => short_channel_id, + None => return self.scorer.channel_penalty_msat(candidate, usage, score_params), + }; + let source = candidate.source(); if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat( - source, target, short_channel_id + &source, &target, short_channel_id ) { let usage = ChannelUsage { inflight_htlc_msat: usage.inflight_htlc_msat.saturating_add(used_liquidity), ..usage }; - self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params) + self.scorer.channel_penalty_msat(candidate, usage, score_params) } else { - self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params) + self.scorer.channel_penalty_msat(candidate, usage, score_params) } } } @@ -929,6 +1052,10 @@ impl Readable for RouteHint { } /// A channel descriptor for a hop along a payment path. +/// +/// While this generally comes from BOLT 11's `r` field, this struct includes more fields than are +/// available in BOLT 11. Thus, encoding and decoding this via `lightning-invoice` is lossy, as +/// fields not supported in BOLT 11 will be stripped. #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)] pub struct RouteHintHop { /// The node_id of the non-target end of the route @@ -955,33 +1082,24 @@ impl_writeable_tlv_based!(RouteHintHop, { }); #[derive(Eq, PartialEq)] +#[repr(align(64))] // Force the size to 64 bytes struct RouteGraphNode { node_id: NodeId, - lowest_fee_to_node: u64, - total_cltv_delta: u32, + score: u64, // The maximum value a yet-to-be-constructed payment path might flow through this node. // This value is upper-bounded by us by: // - how much is needed for a path being constructed // - how much value can channels following this node (up to the destination) can contribute, // considering their capacity and fees value_contribution_msat: u64, - /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC - /// minimum, we use it, plus the fees required at each earlier hop to meet it. - path_htlc_minimum_msat: u64, - /// All penalties incurred from this hop on the way to the destination, as calculated using - /// channel scoring. - path_penalty_msat: u64, + total_cltv_delta: u32, /// The number of hops walked up to this node. path_length_to_node: u8, } impl cmp::Ord for RouteGraphNode { fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering { - let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat) - .saturating_add(other.path_penalty_msat); - let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat) - .saturating_add(self.path_penalty_msat); - other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id)) + other.score.cmp(&self.score).then_with(|| other.node_id.cmp(&self.node_id)) } } @@ -991,133 +1109,302 @@ impl cmp::PartialOrd for RouteGraphNode { } } +// While RouteGraphNode can be laid out with fewer bytes, performance appears to be improved +// substantially when it is laid out at exactly 64 bytes. +// +// Thus, we use `#[repr(C)]` on the struct to force a suboptimal layout and check that it stays 64 +// bytes here. +#[cfg(any(ldk_bench, not(any(test, fuzzing))))] +const _GRAPH_NODE_SMALL: usize = 64 - core::mem::size_of::(); +#[cfg(any(ldk_bench, not(any(test, fuzzing))))] +const _GRAPH_NODE_FIXED_SIZE: usize = core::mem::size_of::() - 64; + +/// A [`CandidateRouteHop::FirstHop`] entry. +#[derive(Clone, Debug)] +pub struct FirstHopCandidate<'a> { + /// Channel details of the first hop + /// + /// [`ChannelDetails::get_outbound_payment_scid`] MUST be `Some` (indicating the channel + /// has been funded and is able to pay), and accessor methods may panic otherwise. + /// + /// [`find_route`] validates this prior to constructing a [`CandidateRouteHop`]. + pub details: &'a ChannelDetails, + /// The node id of the payer, which is also the source side of this candidate route hop. + pub payer_node_id: &'a NodeId, +} + +/// A [`CandidateRouteHop::PublicHop`] entry. +#[derive(Clone, Debug)] +pub struct PublicHopCandidate<'a> { + /// Information about the channel, including potentially its capacity and + /// direction-specific information. + pub info: DirectedChannelInfo<'a>, + /// The short channel ID of the channel, i.e. the identifier by which we refer to this + /// channel. + pub short_channel_id: u64, +} + +/// A [`CandidateRouteHop::PrivateHop`] entry. +#[derive(Clone, Debug)] +pub struct PrivateHopCandidate<'a> { + /// Information about the private hop communicated via BOLT 11. + pub hint: &'a RouteHintHop, + /// Node id of the next hop in BOLT 11 route hint. + pub target_node_id: &'a NodeId +} + +/// A [`CandidateRouteHop::Blinded`] entry. +#[derive(Clone, Debug)] +pub struct BlindedPathCandidate<'a> { + /// Information about the blinded path including the fee, HTLC amount limits, and + /// cryptographic material required to build an HTLC through the given path. + pub hint: &'a (BlindedPayInfo, BlindedPath), + /// Index of the hint in the original list of blinded hints. + /// + /// This is used to cheaply uniquely identify this blinded path, even though we don't have + /// a short channel ID for this hop. + hint_idx: usize, +} + +/// A [`CandidateRouteHop::OneHopBlinded`] entry. +#[derive(Clone, Debug)] +pub struct OneHopBlindedPathCandidate<'a> { + /// Information about the blinded path including the fee, HTLC amount limits, and + /// cryptographic material required to build an HTLC terminating with the given path. + /// + /// Note that the [`BlindedPayInfo`] is ignored here. + pub hint: &'a (BlindedPayInfo, BlindedPath), + /// Index of the hint in the original list of blinded hints. + /// + /// This is used to cheaply uniquely identify this blinded path, even though we don't have + /// a short channel ID for this hop. + hint_idx: usize, +} + /// A wrapper around the various hop representations. /// -/// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`]. +/// Can be used to examine the properties of a hop, +/// potentially to decide whether to include it in a route. #[derive(Clone, Debug)] -enum CandidateRouteHop<'a> { +pub enum CandidateRouteHop<'a> { /// A hop from the payer, where the outbound liquidity is known. - FirstHop { - details: &'a ChannelDetails, - }, - /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown. - PublicHop { - info: DirectedChannelInfo<'a>, - short_channel_id: u64, - }, - /// A hop to the payee found in the BOLT 11 payment invoice, though not necessarily a direct - /// channel. - PrivateHop { - hint: &'a RouteHintHop, - }, - /// The payee's identity is concealed behind blinded paths provided in a BOLT 12 invoice. - Blinded { - hint: &'a (BlindedPayInfo, BlindedPath), - hint_idx: usize, - }, - /// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided - /// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the - /// introduction node and the destination. Useful for tracking that we need to include a blinded - /// path at the end of our [`Route`]. - OneHopBlinded { - hint: &'a (BlindedPayInfo, BlindedPath), - hint_idx: usize, - }, + FirstHop(FirstHopCandidate<'a>), + /// A hop found in the [`ReadOnlyNetworkGraph`]. + PublicHop(PublicHopCandidate<'a>), + /// A private hop communicated by the payee, generally via a BOLT 11 invoice. + /// + /// Because BOLT 11 route hints can take multiple hops to get to the destination, this may not + /// terminate at the payee. + PrivateHop(PrivateHopCandidate<'a>), + /// A blinded path which starts with an introduction point and ultimately terminates with the + /// payee. + /// + /// Because we don't know the payee's identity, [`CandidateRouteHop::target`] will return + /// `None` in this state. + /// + /// Because blinded paths are "all or nothing", and we cannot use just one part of a blinded + /// path, the full path is treated as a single [`CandidateRouteHop`]. + Blinded(BlindedPathCandidate<'a>), + /// Similar to [`Self::Blinded`], but the path here only has one hop. + /// + /// While we treat this similarly to [`CandidateRouteHop::Blinded`] in many respects (e.g. + /// returning `None` from [`CandidateRouteHop::target`]), in this case we do actually know the + /// payee's identity - it's the introduction point! + /// + /// [`BlindedPayInfo`] provided for 1-hop blinded paths is ignored because it is meant to apply + /// to the hops *between* the introduction node and the destination. + /// + /// This primarily exists to track that we need to included a blinded path at the end of our + /// [`Route`], even though it doesn't actually add an additional hop in the payment. + OneHopBlinded(OneHopBlindedPathCandidate<'a>), } impl<'a> CandidateRouteHop<'a> { + /// Returns the short channel ID for this hop, if one is known. + /// + /// This SCID could be an alias or a globally unique SCID, and thus is only expected to + /// uniquely identify this channel in conjunction with the [`CandidateRouteHop::source`]. + /// + /// Returns `Some` as long as the candidate is a [`CandidateRouteHop::PublicHop`], a + /// [`CandidateRouteHop::PrivateHop`] from a BOLT 11 route hint, or a + /// [`CandidateRouteHop::FirstHop`] with a known [`ChannelDetails::get_outbound_payment_scid`] + /// (which is always true for channels which are funded and ready for use). + /// + /// In other words, this should always return `Some` as long as the candidate hop is not a + /// [`CandidateRouteHop::Blinded`] or a [`CandidateRouteHop::OneHopBlinded`]. + /// + /// Note that this is deliberately not public as it is somewhat of a footgun because it doesn't + /// define a global namespace. + #[inline] fn short_channel_id(&self) -> Option { match self { - CandidateRouteHop::FirstHop { details } => Some(details.get_outbound_payment_scid().unwrap()), - CandidateRouteHop::PublicHop { short_channel_id, .. } => Some(*short_channel_id), - CandidateRouteHop::PrivateHop { hint } => Some(hint.short_channel_id), - CandidateRouteHop::Blinded { .. } => None, - CandidateRouteHop::OneHopBlinded { .. } => None, + CandidateRouteHop::FirstHop(hop) => hop.details.get_outbound_payment_scid(), + CandidateRouteHop::PublicHop(hop) => Some(hop.short_channel_id), + CandidateRouteHop::PrivateHop(hop) => Some(hop.hint.short_channel_id), + CandidateRouteHop::Blinded(_) => None, + CandidateRouteHop::OneHopBlinded(_) => None, + } + } + + /// Returns the globally unique short channel ID for this hop, if one is known. + /// + /// This only returns `Some` if the channel is public (either our own, or one we've learned + /// from the public network graph), and thus the short channel ID we have for this channel is + /// globally unique and identifies this channel in a global namespace. + #[inline] + pub fn globally_unique_short_channel_id(&self) -> Option { + match self { + CandidateRouteHop::FirstHop(hop) => if hop.details.is_public { hop.details.short_channel_id } else { None }, + CandidateRouteHop::PublicHop(hop) => Some(hop.short_channel_id), + CandidateRouteHop::PrivateHop(_) => None, + CandidateRouteHop::Blinded(_) => None, + CandidateRouteHop::OneHopBlinded(_) => None, } } // NOTE: This may alloc memory so avoid calling it in a hot code path. fn features(&self) -> ChannelFeatures { match self { - CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(), - CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(), - CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(), - CandidateRouteHop::Blinded { .. } => ChannelFeatures::empty(), - CandidateRouteHop::OneHopBlinded { .. } => ChannelFeatures::empty(), + CandidateRouteHop::FirstHop(hop) => hop.details.counterparty.features.to_context(), + CandidateRouteHop::PublicHop(hop) => hop.info.channel().features.clone(), + CandidateRouteHop::PrivateHop(_) => ChannelFeatures::empty(), + CandidateRouteHop::Blinded(_) => ChannelFeatures::empty(), + CandidateRouteHop::OneHopBlinded(_) => ChannelFeatures::empty(), } } - fn cltv_expiry_delta(&self) -> u32 { + /// Returns the required difference in HTLC CLTV expiry between the [`Self::source`] and the + /// next-hop for an HTLC taking this hop. + /// + /// This is the time that the node(s) in this hop have to claim the HTLC on-chain if the + /// next-hop goes on chain with a payment preimage. + #[inline] + pub fn cltv_expiry_delta(&self) -> u32 { match self { - CandidateRouteHop::FirstHop { .. } => 0, - CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32, - CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32, - CandidateRouteHop::Blinded { hint, .. } => hint.0.cltv_expiry_delta as u32, - CandidateRouteHop::OneHopBlinded { .. } => 0, + CandidateRouteHop::FirstHop(_) => 0, + CandidateRouteHop::PublicHop(hop) => hop.info.direction().cltv_expiry_delta as u32, + CandidateRouteHop::PrivateHop(hop) => hop.hint.cltv_expiry_delta as u32, + CandidateRouteHop::Blinded(hop) => hop.hint.0.cltv_expiry_delta as u32, + CandidateRouteHop::OneHopBlinded(_) => 0, } } - fn htlc_minimum_msat(&self) -> u64 { + /// Returns the minimum amount that can be sent over this hop, in millisatoshis. + #[inline] + pub fn htlc_minimum_msat(&self) -> u64 { match self { - CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat, - CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat, - CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0), - CandidateRouteHop::Blinded { hint, .. } => hint.0.htlc_minimum_msat, + CandidateRouteHop::FirstHop(hop) => hop.details.next_outbound_htlc_minimum_msat, + CandidateRouteHop::PublicHop(hop) => hop.info.direction().htlc_minimum_msat, + CandidateRouteHop::PrivateHop(hop) => hop.hint.htlc_minimum_msat.unwrap_or(0), + CandidateRouteHop::Blinded(hop) => hop.hint.0.htlc_minimum_msat, CandidateRouteHop::OneHopBlinded { .. } => 0, } } - fn fees(&self) -> RoutingFees { + /// Returns the fees that must be paid to route an HTLC over this channel. + #[inline] + pub fn fees(&self) -> RoutingFees { match self { - CandidateRouteHop::FirstHop { .. } => RoutingFees { + CandidateRouteHop::FirstHop(_) => RoutingFees { base_msat: 0, proportional_millionths: 0, }, - CandidateRouteHop::PublicHop { info, .. } => info.direction().fees, - CandidateRouteHop::PrivateHop { hint } => hint.fees, - CandidateRouteHop::Blinded { hint, .. } => { + CandidateRouteHop::PublicHop(hop) => hop.info.direction().fees, + CandidateRouteHop::PrivateHop(hop) => hop.hint.fees, + CandidateRouteHop::Blinded(hop) => { RoutingFees { - base_msat: hint.0.fee_base_msat, - proportional_millionths: hint.0.fee_proportional_millionths + base_msat: hop.hint.0.fee_base_msat, + proportional_millionths: hop.hint.0.fee_proportional_millionths } }, - CandidateRouteHop::OneHopBlinded { .. } => + CandidateRouteHop::OneHopBlinded(_) => RoutingFees { base_msat: 0, proportional_millionths: 0 }, } } + /// Fetch the effective capacity of this hop. + /// + /// Note that this may be somewhat expensive, so calls to this should be limited and results + /// cached! fn effective_capacity(&self) -> EffectiveCapacity { match self { - CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity { - liquidity_msat: details.next_outbound_htlc_limit_msat, + CandidateRouteHop::FirstHop(hop) => EffectiveCapacity::ExactLiquidity { + liquidity_msat: hop.details.next_outbound_htlc_limit_msat, }, - CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(), - CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} => + CandidateRouteHop::PublicHop(hop) => hop.info.effective_capacity(), + CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }, .. }) => EffectiveCapacity::HintMaxHTLC { amount_msat: *max }, - CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} => + CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: RouteHintHop { htlc_maximum_msat: None, .. }, .. }) => EffectiveCapacity::Infinite, - CandidateRouteHop::Blinded { hint, .. } => - EffectiveCapacity::HintMaxHTLC { amount_msat: hint.0.htlc_maximum_msat }, - CandidateRouteHop::OneHopBlinded { .. } => EffectiveCapacity::Infinite, + CandidateRouteHop::Blinded(hop) => + EffectiveCapacity::HintMaxHTLC { amount_msat: hop.hint.0.htlc_maximum_msat }, + CandidateRouteHop::OneHopBlinded(_) => EffectiveCapacity::Infinite, } } - fn id(&self, channel_direction: bool /* src_node_id < target_node_id */) -> CandidateHopId { + /// Returns an ID describing the given hop. + /// + /// See the docs on [`CandidateHopId`] for when this is, or is not, unique. + #[inline] + fn id(&self) -> CandidateHopId { match self { - CandidateRouteHop::Blinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx), - CandidateRouteHop::OneHopBlinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx), - _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), channel_direction)), + CandidateRouteHop::Blinded(hop) => CandidateHopId::Blinded(hop.hint_idx), + CandidateRouteHop::OneHopBlinded(hop) => CandidateHopId::Blinded(hop.hint_idx), + _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), self.source() < self.target().unwrap())), } } fn blinded_path(&self) -> Option<&'a BlindedPath> { match self { - CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => { + CandidateRouteHop::Blinded(BlindedPathCandidate { hint, .. }) | CandidateRouteHop::OneHopBlinded(OneHopBlindedPathCandidate { hint, .. }) => { Some(&hint.1) }, _ => None, } } + /// Returns the source node id of current hop. + /// + /// Source node id refers to the node forwarding the HTLC through this hop. + /// + /// For [`Self::FirstHop`] we return payer's node id. + #[inline] + pub fn source(&self) -> NodeId { + match self { + CandidateRouteHop::FirstHop(hop) => *hop.payer_node_id, + CandidateRouteHop::PublicHop(hop) => *hop.info.source(), + CandidateRouteHop::PrivateHop(hop) => hop.hint.src_node_id.into(), + CandidateRouteHop::Blinded(hop) => hop.hint.1.introduction_node_id.into(), + CandidateRouteHop::OneHopBlinded(hop) => hop.hint.1.introduction_node_id.into(), + } + } + /// Returns the target node id of this hop, if known. + /// + /// Target node id refers to the node receiving the HTLC after this hop. + /// + /// For [`Self::Blinded`] we return `None` because the ultimate destination after the blinded + /// path is unknown. + /// + /// For [`Self::OneHopBlinded`] we return `None` because the target is the same as the source, + /// and such a return value would be somewhat nonsensical. + #[inline] + pub fn target(&self) -> Option { + match self { + CandidateRouteHop::FirstHop(hop) => Some(hop.details.counterparty.node_id.into()), + CandidateRouteHop::PublicHop(hop) => Some(*hop.info.target()), + CandidateRouteHop::PrivateHop(hop) => Some(*hop.target_node_id), + CandidateRouteHop::Blinded(_) => None, + CandidateRouteHop::OneHopBlinded(_) => None, + } + } } +/// A unique(ish) identifier for a specific [`CandidateRouteHop`]. +/// +/// For blinded paths, this ID is unique only within a given [`find_route`] call. +/// +/// For other hops, because SCIDs between private channels and public channels can conflict, this +/// isn't guaranteed to be unique at all. +/// +/// For our uses, this is generally fine, but it is not public as it is otherwise a rather +/// difficult-to-use API. #[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)] enum CandidateHopId { /// Contains (scid, src_node_id < target_node_id) @@ -1159,18 +1446,15 @@ fn iter_equal(mut iter_a: I1, mut iter_b: I2) /// 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)] +#[repr(C)] // Force fields to appear in the order we define them. struct PathBuildingHop<'a> { - // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so - // is a larger refactor and will require careful performance analysis. - node_id: NodeId, candidate: CandidateRouteHop<'a>, - fee_msat: u64, - - /// All the fees paid *after* this channel on the way to the destination - next_hops_fee_msat: u64, - /// Fee paid for the use of the current channel (see candidate.fees()). - /// The value will be actually deducted from the counterparty balance on the previous link. - hop_use_fee_msat: u64, + /// If we've already processed a node as the best node, we shouldn't process it again. Normally + /// we'd just ignore it if we did as all channels would have a higher new fee, but because we + /// may decrease the amounts in use as we walk the graph, the actual calculated fee may + /// decrease as well. Thus, we have to explicitly track which nodes have been processed and + /// avoid processing them again. + was_processed: bool, /// Used to compare channels when choosing the for routing. /// Includes paying for the use of a hop and the following hops, as well as /// an estimated cost of reaching this hop. @@ -1182,12 +1466,20 @@ struct PathBuildingHop<'a> { /// All penalties incurred from this channel on the way to the destination, as calculated using /// channel scoring. path_penalty_msat: u64, - /// If we've already processed a node as the best node, we shouldn't process it again. Normally - /// we'd just ignore it if we did as all channels would have a higher new fee, but because we - /// may decrease the amounts in use as we walk the graph, the actual calculated fee may - /// decrease as well. Thus, we have to explicitly track which nodes have been processed and - /// avoid processing them again. - was_processed: bool, + + // The last 16 bytes are on the next cache line by default in glibc's malloc. Thus, we should + // only place fields which are not hot there. Luckily, the next three fields are only read if + // we end up on the selected path, and only in the final path layout phase, so we don't care + // too much if reading them is slow. + + fee_msat: u64, + + /// All the fees paid *after* this channel on the way to the destination + next_hops_fee_msat: u64, + /// Fee paid for the use of the current channel (see candidate.fees()). + /// The value will be actually deducted from the counterparty balance on the previous link. + hop_use_fee_msat: u64, + #[cfg(all(not(ldk_bench), any(test, fuzzing)))] // In tests, we apply further sanity checks on cases where we skip nodes we already processed // to ensure it is specifically in cases where the fee has gone down because of a decrease in @@ -1196,11 +1488,23 @@ struct PathBuildingHop<'a> { value_contribution_msat: u64, } +// Checks that the entries in the `find_route` `dist` map fit in (exactly) two standard x86-64 +// cache lines. Sadly, they're not guaranteed to actually lie on a cache line (and in fact, +// generally won't, because at least glibc's malloc will align to a nice, big, round +// boundary...plus 16), but at least it will reduce the amount of data we'll need to load. +// +// Note that these assertions only pass on somewhat recent rustc, and thus are gated on the +// ldk_bench flag. +#[cfg(ldk_bench)] +const _NODE_MAP_SIZE_TWO_CACHE_LINES: usize = 128 - core::mem::size_of::<(NodeId, PathBuildingHop)>(); +#[cfg(ldk_bench)] +const _NODE_MAP_SIZE_EXACTLY_CACHE_LINES: usize = core::mem::size_of::<(NodeId, PathBuildingHop)>() - 128; + impl<'a> core::fmt::Debug for PathBuildingHop<'a> { fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> { let mut debug_struct = f.debug_struct("PathBuildingHop"); debug_struct - .field("node_id", &self.node_id) + .field("node_id", &self.candidate.target()) .field("short_channel_id", &self.candidate.short_channel_id()) .field("total_fee_msat", &self.total_fee_msat) .field("next_hops_fee_msat", &self.next_hops_fee_msat) @@ -1382,17 +1686,17 @@ struct LoggedCandidateHop<'a>(&'a CandidateRouteHop<'a>); impl<'a> fmt::Display for LoggedCandidateHop<'a> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { match self.0 { - CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => { + CandidateRouteHop::Blinded(BlindedPathCandidate { hint, .. }) | CandidateRouteHop::OneHopBlinded(OneHopBlindedPathCandidate { hint, .. }) => { "blinded route hint with introduction node id ".fmt(f)?; hint.1.introduction_node_id.fmt(f)?; " and blinding point ".fmt(f)?; hint.1.blinding_point.fmt(f) }, - CandidateRouteHop::FirstHop { .. } => { + CandidateRouteHop::FirstHop(_) => { "first hop with SCID ".fmt(f)?; self.0.short_channel_id().unwrap().fmt(f) }, - CandidateRouteHop::PrivateHop { .. } => { + CandidateRouteHop::PrivateHop(_) => { "route hint with SCID ".fmt(f)?; self.0.short_channel_id().unwrap().fmt(f) }, @@ -1650,6 +1954,20 @@ where L::Target: Logger { } } + let mut private_hop_key_cache = HashMap::with_capacity( + payment_params.payee.unblinded_route_hints().iter().map(|path| path.0.len()).sum() + ); + + // Because we store references to private hop node_ids in `dist`, below, we need them to exist + // (as `NodeId`, not `PublicKey`) for the lifetime of `dist`. Thus, we calculate all the keys + // we'll need here and simply fetch them when routing. + private_hop_key_cache.insert(maybe_dummy_payee_pk, NodeId::from_pubkey(&maybe_dummy_payee_pk)); + for route in payment_params.payee.unblinded_route_hints().iter() { + for hop in route.0.iter() { + private_hop_key_cache.insert(hop.src_node_id, NodeId::from_pubkey(&hop.src_node_id)); + } + } + // The main heap containing all candidate next-hops sorted by their score (max(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. @@ -1722,11 +2040,11 @@ where L::Target: Logger { let mut num_ignored_htlc_minimum_msat_limit: u32 = 0; macro_rules! add_entry { - // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop. + // Adds entry which goes from $candidate.source() to $candidate.target() over the $candidate hop. // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one, // since that value has to be transferred over this channel. // Returns the contribution amount of $candidate if the channel caused an update to `targets`. - ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr, + ( $candidate: expr, $next_hops_fee_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { { // We "return" whether we updated the path at the end, and how much we can route via @@ -1736,7 +2054,8 @@ 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 { + let src_node_id = $candidate.source(); + if Some(src_node_id) != $candidate.target() { let scid_opt = $candidate.short_channel_id(); let effective_capacity = $candidate.effective_capacity(); let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half); @@ -1750,7 +2069,7 @@ where L::Target: Logger { // We do this for now, but this is a subject for removal. if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) { let used_liquidity_msat = used_liquidities - .get(&$candidate.id($src_node_id < $dest_node_id)) + .get(&$candidate.id()) .map_or(0, |used_liquidity_msat| { available_value_contribution_msat = available_value_contribution_msat .saturating_sub(*used_liquidity_msat); @@ -1795,12 +2114,12 @@ 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, - CandidateRouteHop::OneHopBlinded { .. } => true, - _ => false, + let (should_log_candidate, first_hop_details) = match $candidate { + CandidateRouteHop::FirstHop(hop) => (true, Some(hop.details)), + CandidateRouteHop::PrivateHop(_) => (true, None), + CandidateRouteHop::Blinded(_) => (true, None), + CandidateRouteHop::OneHopBlinded(_) => (true, None), + _ => (false, None), }; // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't @@ -1810,6 +2129,13 @@ where L::Target: Logger { if !contributes_sufficient_value { if should_log_candidate { log_trace!(logger, "Ignoring {} due to insufficient value contribution.", LoggedCandidateHop(&$candidate)); + + if let Some(details) = first_hop_details { + log_trace!(logger, + "First hop candidate next_outbound_htlc_limit_msat: {}", + details.next_outbound_htlc_limit_msat, + ); + } } num_ignored_value_contribution += 1; } else if exceeds_max_path_length { @@ -1820,6 +2146,14 @@ where L::Target: Logger { } else if exceeds_cltv_delta_limit { if should_log_candidate { log_trace!(logger, "Ignoring {} due to exceeding CLTV delta limit.", LoggedCandidateHop(&$candidate)); + + if let Some(_) = first_hop_details { + log_trace!(logger, + "First hop candidate cltv_expiry_delta: {}. Limit: {}", + hop_total_cltv_delta, + max_total_cltv_expiry_delta, + ); + } } num_ignored_cltv_delta_limit += 1; } else if payment_failed_on_this_channel { @@ -1832,6 +2166,13 @@ where L::Target: Logger { log_trace!(logger, "Ignoring {} to avoid overpaying to meet htlc_minimum_msat limit.", LoggedCandidateHop(&$candidate)); + + if let Some(details) = first_hop_details { + log_trace!(logger, + "First hop candidate next_outbound_htlc_minimum_msat: {}", + details.next_outbound_htlc_minimum_msat, + ); + } } num_ignored_avoid_overpayment += 1; hit_minimum_limit = true; @@ -1845,15 +2186,14 @@ where L::Target: Logger { ); let path_htlc_minimum_msat = compute_fees_saturating(curr_min, $candidate.fees()) .saturating_add(curr_min); - let hm_entry = dist.entry($src_node_id); + 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 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. + // as a way to reach the $candidate.target() node. PathBuildingHop { - node_id: $dest_node_id.clone(), candidate: $candidate.clone(), fee_msat: 0, next_hops_fee_msat: u64::max_value(), @@ -1882,7 +2222,7 @@ 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 { + if src_node_id != our_node_id { // Note that `u64::max_value` means we'll always fail the // `old_entry.total_fee_msat > total_fee_msat` check below hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees()); @@ -1893,6 +2233,14 @@ where L::Target: Logger { if total_fee_msat > max_total_routing_fee_msat { if should_log_candidate { log_trace!(logger, "Ignoring {} due to exceeding max total routing fee limit.", LoggedCandidateHop(&$candidate)); + + if let Some(_) = first_hop_details { + log_trace!(logger, + "First hop candidate routing fee: {}. Limit: {}", + total_fee_msat, + max_total_routing_fee_msat, + ); + } } num_ignored_total_fee_limit += 1; } else { @@ -1901,22 +2249,15 @@ where L::Target: Logger { inflight_htlc_msat: used_liquidity_msat, effective_capacity, }; - let channel_penalty_msat = scid_opt.map_or(0, - |scid| scorer.channel_penalty_msat(scid, &$src_node_id, &$dest_node_id, - channel_usage, score_params)); + let channel_penalty_msat = + scorer.channel_penalty_msat($candidate, + channel_usage, + score_params); let path_penalty_msat = $next_hops_path_penalty_msat .saturating_add(channel_penalty_msat); - let new_graph_node = RouteGraphNode { - node_id: $src_node_id, - lowest_fee_to_node: total_fee_msat, - total_cltv_delta: hop_total_cltv_delta, - value_contribution_msat, - path_htlc_minimum_msat, - path_penalty_msat, - path_length_to_node, - }; - // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id), + // Update the way of reaching $candidate.source() + // with the given short_channel_id (from $candidate.target()), // 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, @@ -1938,11 +2279,17 @@ where L::Target: Logger { .saturating_add(path_penalty_msat); if !old_entry.was_processed && new_cost < old_cost { + let new_graph_node = RouteGraphNode { + node_id: src_node_id, + score: cmp::max(total_fee_msat, path_htlc_minimum_msat).saturating_add(path_penalty_msat), + total_cltv_delta: hop_total_cltv_delta, + value_contribution_msat, + path_length_to_node, + }; targets.push(new_graph_node); old_entry.next_hops_fee_msat = $next_hops_fee_msat; 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.candidate = $candidate.clone(); old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat; @@ -1988,6 +2335,13 @@ where L::Target: Logger { log_trace!(logger, "Ignoring {} due to its htlc_minimum_msat limit.", LoggedCandidateHop(&$candidate)); + + if let Some(details) = first_hop_details { + log_trace!(logger, + "First hop candidate next_outbound_htlc_minimum_msat: {}", + details.next_outbound_htlc_minimum_msat, + ); + } } num_ignored_htlc_minimum_msat_limit += 1; } @@ -2005,28 +2359,38 @@ where L::Target: Logger { // meaning how much will be paid in fees after this node (to the best of our knowledge). // This data can later be helpful to optimize routing (pay lower fees). macro_rules! add_entries_to_cheapest_to_target_node { - ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, - $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr, + ( $node: expr, $node_id: expr, $next_hops_value_contribution: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { + let fee_to_target_msat; + let next_hops_path_htlc_minimum_msat; + let next_hops_path_penalty_msat; let skip_node = if let Some(elem) = dist.get_mut(&$node_id) { let was_processed = elem.was_processed; elem.was_processed = true; + fee_to_target_msat = elem.total_fee_msat; + next_hops_path_htlc_minimum_msat = elem.path_htlc_minimum_msat; + next_hops_path_penalty_msat = elem.path_penalty_msat; was_processed } else { // Entries are added to dist in add_entry!() when there is a channel from a node. // Because there are no channels from payee, it will not have a dist entry at this point. // If we're processing any other node, it is always be the result of a channel from it. debug_assert_eq!($node_id, maybe_dummy_payee_node_id); + fee_to_target_msat = 0; + next_hops_path_htlc_minimum_msat = 0; + next_hops_path_penalty_msat = 0; false }; if !skip_node { if let Some(first_channels) = first_hop_targets.get(&$node_id) { for details in first_channels { - let candidate = CandidateRouteHop::FirstHop { details }; - add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat, + let candidate = CandidateRouteHop::FirstHop(FirstHopCandidate { + details, payer_node_id: &our_node_id, + }); + add_entry!(&candidate, fee_to_target_msat, $next_hops_value_contribution, - $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat, + next_hops_path_htlc_minimum_msat, next_hops_path_penalty_msat, $next_hops_cltv_delta, $next_hops_path_length); } } @@ -2044,15 +2408,15 @@ where L::Target: Logger { if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) { if first_hops.is_none() || *source != our_node_id { if directed_channel.direction().enabled { - let candidate = CandidateRouteHop::PublicHop { + let candidate = CandidateRouteHop::PublicHop(PublicHopCandidate { info: directed_channel, short_channel_id: *chan_id, - }; - add_entry!(candidate, *source, $node_id, - $fee_to_target_msat, + }); + add_entry!(&candidate, + fee_to_target_msat, $next_hops_value_contribution, - $next_hops_path_htlc_minimum_msat, - $next_hops_path_penalty_msat, + next_hops_path_htlc_minimum_msat, + next_hops_path_penalty_msat, $next_hops_cltv_delta, $next_hops_path_length); } } @@ -2078,8 +2442,10 @@ where L::Target: Logger { // place where it could be added. payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| { for details in first_channels { - let candidate = CandidateRouteHop::FirstHop { details }; - let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat, + let candidate = CandidateRouteHop::FirstHop(FirstHopCandidate { + details, payer_node_id: &our_node_id, + }); + let added = add_entry!(&candidate, 0, path_value_msat, 0, 0u64, 0, 0).is_some(); log_trace!(logger, "{} direct route to payee via {}", if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate)); @@ -2095,7 +2461,7 @@ where L::Target: Logger { // If not, targets.pop() will not even let us enter the loop in step 2. None => {}, Some(node) => { - add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0, 0u64, 0, 0); + add_entries_to_cheapest_to_target_node!(node, payee, path_value_msat, 0, 0); }, }); @@ -2113,10 +2479,10 @@ where L::Target: Logger { network_nodes.get(&intro_node_id).is_some(); if !have_intro_node_in_graph || our_node_id == intro_node_id { continue } let candidate = if hint.1.blinded_hops.len() == 1 { - CandidateRouteHop::OneHopBlinded { hint, hint_idx } - } else { CandidateRouteHop::Blinded { hint, hint_idx } }; + CandidateRouteHop::OneHopBlinded(OneHopBlindedPathCandidate { hint, hint_idx }) + } else { CandidateRouteHop::Blinded(BlindedPathCandidate { hint, hint_idx }) }; let mut path_contribution_msat = path_value_msat; - if let Some(hop_used_msat) = add_entry!(candidate, intro_node_id, maybe_dummy_payee_node_id, + if let Some(hop_used_msat) = add_entry!(&candidate, 0, path_contribution_msat, 0, 0_u64, 0, 0) { path_contribution_msat = hop_used_msat; @@ -2125,14 +2491,16 @@ where L::Target: Logger { sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey); for details in first_channels { - let first_hop_candidate = CandidateRouteHop::FirstHop { details }; + let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate { + details, payer_node_id: &our_node_id, + }); let blinded_path_fee = match compute_fees(path_contribution_msat, candidate.fees()) { Some(fee) => fee, None => continue }; let path_min = candidate.htlc_minimum_msat().saturating_add( compute_fees_saturating(candidate.htlc_minimum_msat(), candidate.fees())); - add_entry!(first_hop_candidate, our_node_id, intro_node_id, blinded_path_fee, + add_entry!(&first_hop_candidate, blinded_path_fee, path_contribution_msat, path_min, 0_u64, candidate.cltv_expiry_delta(), candidate.blinded_path().map_or(1, |bp| bp.blinded_hops.len() as u8)); } @@ -2164,8 +2532,7 @@ where L::Target: Logger { let mut aggregate_path_contribution_msat = path_value_msat; for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() { - let source = NodeId::from_pubkey(&hop.src_node_id); - let target = NodeId::from_pubkey(&prev_hop_id); + let target = private_hop_key_cache.get(&prev_hop_id).unwrap(); if let Some(first_channels) = first_hop_targets.get(&target) { if first_channels.iter().any(|d| d.outbound_scid_alias == Some(hop.short_channel_id)) { @@ -2178,13 +2545,13 @@ where L::Target: Logger { let candidate = network_channels .get(&hop.short_channel_id) .and_then(|channel| channel.as_directed_to(&target)) - .map(|(info, _)| CandidateRouteHop::PublicHop { + .map(|(info, _)| CandidateRouteHop::PublicHop(PublicHopCandidate { info, short_channel_id: hop.short_channel_id, - }) - .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop }); + })) + .unwrap_or_else(|| CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: hop, target_node_id: target })); - if let Some(hop_used_msat) = add_entry!(candidate, source, target, + if let Some(hop_used_msat) = add_entry!(&candidate, aggregate_next_hops_fee_msat, aggregate_path_contribution_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) @@ -2198,7 +2565,7 @@ where L::Target: Logger { } let used_liquidity_msat = used_liquidities - .get(&candidate.id(source < target)).copied() + .get(&candidate.id()).copied() .unwrap_or(0); let channel_usage = ChannelUsage { amount_msat: final_value_msat + aggregate_next_hops_fee_msat, @@ -2206,7 +2573,7 @@ where L::Target: Logger { effective_capacity: candidate.effective_capacity(), }; let channel_penalty_msat = scorer.channel_penalty_msat( - hop.short_channel_id, &source, &target, channel_usage, score_params + &candidate, channel_usage, score_params ); aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat .saturating_add(channel_penalty_msat); @@ -2222,8 +2589,10 @@ where L::Target: Logger { sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey); for details in first_channels { - let first_hop_candidate = CandidateRouteHop::FirstHop { details }; - add_entry!(first_hop_candidate, our_node_id, target, + let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate { + details, payer_node_id: &our_node_id, + }); + add_entry!(&first_hop_candidate, aggregate_next_hops_fee_msat, aggregate_path_contribution_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length); @@ -2267,9 +2636,10 @@ where L::Target: Logger { sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey); for details in first_channels { - let first_hop_candidate = CandidateRouteHop::FirstHop { details }; - add_entry!(first_hop_candidate, our_node_id, - NodeId::from_pubkey(&hop.src_node_id), + let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate { + details, payer_node_id: &our_node_id, + }); + add_entry!(&first_hop_candidate, aggregate_next_hops_fee_msat, aggregate_path_contribution_msat, aggregate_next_hops_path_htlc_minimum_msat, @@ -2298,7 +2668,7 @@ where L::Target: Logger { // Both these cases (and other cases except reaching recommended_value_msat) mean that // paths_collection will be stopped because found_new_path==false. // This is not necessarily a routing failure. - 'path_construction: while let Some(RouteGraphNode { node_id, lowest_fee_to_node, total_cltv_delta, mut value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, path_length_to_node, .. }) = targets.pop() { + 'path_construction: while let Some(RouteGraphNode { node_id, total_cltv_delta, mut value_contribution_msat, path_length_to_node, .. }) = targets.pop() { // Since we're going payee-to-payer, hitting our node as a target means we should stop // traversing the graph and arrange the path out of what we found. @@ -2308,10 +2678,13 @@ 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) { + let target = ordered_hops.last().unwrap().0.candidate.target().unwrap_or(maybe_dummy_payee_node_id); + if let Some(first_channels) = first_hop_targets.get(&target) { for details in first_channels { - if let Some(scid) = ordered_hops.last().unwrap().0.candidate.short_channel_id() { - if details.get_outbound_payment_scid().unwrap() == scid { + if let CandidateRouteHop::FirstHop(FirstHopCandidate { details: last_hop_details, .. }) + = ordered_hops.last().unwrap().0.candidate + { + if details.get_outbound_payment_scid() == last_hop_details.get_outbound_payment_scid() { ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context(); features_set = true; break; @@ -2320,7 +2693,7 @@ where L::Target: Logger { } } if !features_set { - if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) { + if let Some(node) = network_nodes.get(&target) { if let Some(node_info) = node.announcement_info.as_ref() { ordered_hops.last_mut().unwrap().1 = node_info.features.clone(); } else { @@ -2337,11 +2710,11 @@ where L::Target: Logger { // save this path for the payment route. Also, update the liquidity // remaining on the used hops, so that we take them into account // while looking for more paths. - if ordered_hops.last().unwrap().0.node_id == maybe_dummy_payee_node_id { + if target == maybe_dummy_payee_node_id { break 'path_walk; } - new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) { + new_entry = match dist.remove(&target) { Some(payment_hop) => payment_hop, // We can't arrive at None because, if we ever add an entry to targets, // we also fill in the entry in dist (see add_entry!). @@ -2380,12 +2753,10 @@ where L::Target: Logger { // Remember that we used these channels so that we don't rely // on the same liquidity in future paths. let mut prevented_redundant_path_selection = false; - let prev_hop_iter = core::iter::once(&our_node_id) - .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id)); - for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) { + for (hop, _) in payment_path.hops.iter() { let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat; let used_liquidity_msat = used_liquidities - .entry(hop.candidate.id(*prev_hop < hop.node_id)) + .entry(hop.candidate.id()) .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat) .or_insert(spent_on_hop_msat); let hop_capacity = hop.candidate.effective_capacity(); @@ -2406,8 +2777,10 @@ where L::Target: Logger { log_trace!(logger, "Disabling route candidate {} for future path building iterations to avoid duplicates.", LoggedCandidateHop(victim_candidate)); - *used_liquidities.entry(victim_candidate.id(false)).or_default() = exhausted; - *used_liquidities.entry(victim_candidate.id(true)).or_default() = exhausted; + if let Some(scid) = victim_candidate.short_channel_id() { + *used_liquidities.entry(CandidateHopId::Clear((scid, false))).or_default() = exhausted; + *used_liquidities.entry(CandidateHopId::Clear((scid, true))).or_default() = exhausted; + } } // Track the total amount all our collected paths allow to send so that we know @@ -2430,8 +2803,8 @@ where L::Target: Logger { match network_nodes.get(&node_id) { None => {}, Some(node) => { - add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node, - value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, + add_entries_to_cheapest_to_target_node!(node, node_id, + value_contribution_msat, total_cltv_delta, path_length_to_node); }, } @@ -2553,15 +2926,15 @@ where L::Target: Logger { selected_route.sort_unstable_by_key(|path| { let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize]; debug_assert!(path.hops.len() <= key.len()); - for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id(true)).zip(key.iter_mut()) { + for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id()).zip(key.iter_mut()) { *key = scid; } key }); for idx in 0..(selected_route.len() - 1) { if idx + 1 >= selected_route.len() { break; } - if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)), - selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) { + if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(), h.0.candidate.target())), + selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(), h.0.candidate.target()))) { let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat(); selected_route[idx].update_value_and_recompute_fees(new_value); selected_route.remove(idx + 1); @@ -2571,29 +2944,29 @@ where L::Target: Logger { let mut paths = Vec::new(); for payment_path in selected_route { let mut hops = Vec::with_capacity(payment_path.hops.len()); - let mut prev_hop_node_id = our_node_id; for (hop, node_features) in payment_path.hops.iter() .filter(|(h, _)| h.candidate.short_channel_id().is_some()) { - let maybe_announced_channel = if let CandidateRouteHop::PublicHop { .. } = hop.candidate { + let target = hop.candidate.target().expect("target is defined when short_channel_id is defined"); + let maybe_announced_channel = if let CandidateRouteHop::PublicHop(_) = hop.candidate { // If we sourced the hop from the graph we're sure the target node is announced. true - } else if let CandidateRouteHop::FirstHop { details } = hop.candidate { + } else if let CandidateRouteHop::FirstHop(first_hop) = &hop.candidate { // If this is a first hop we also know if it's announced. - details.is_public + first_hop.details.is_public } else { // If we sourced it any other way, we double-check the network graph to see if // there are announced channels between the endpoints. If so, the hop might be // referring to any of the announced channels, as its `short_channel_id` might be // an alias, in which case we don't take any chances here. - network_graph.node(&hop.node_id).map_or(false, |hop_node| + network_graph.node(&target).map_or(false, |hop_node| hop_node.channels.iter().any(|scid| network_graph.channel(*scid) - .map_or(false, |c| c.as_directed_from(&prev_hop_node_id).is_some())) + .map_or(false, |c| c.as_directed_from(&hop.candidate.source()).is_some())) ) }; hops.push(RouteHop { - pubkey: PublicKey::from_slice(hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?, + pubkey: PublicKey::from_slice(target.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &target), action: ErrorAction::IgnoreAndLog(Level::Trace)})?, node_features: node_features.clone(), short_channel_id: hop.candidate.short_channel_id().unwrap(), channel_features: hop.candidate.features(), @@ -2601,8 +2974,6 @@ where L::Target: Logger { cltv_expiry_delta: hop.candidate.cltv_expiry_delta(), maybe_announced_channel, }); - - prev_hop_node_id = hop.node_id; } let mut final_cltv_delta = final_cltv_expiry_delta; let blinded_tail = payment_path.hops.last().and_then(|(h, _)| { @@ -2765,13 +3136,13 @@ fn build_route_from_hops_internal( impl ScoreLookUp for HopScorer { type ScoreParams = (); - fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId, + fn channel_penalty_msat(&self, candidate: &CandidateRouteHop, _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64 { let mut cur_id = self.our_node_id; for i in 0..self.hop_ids.len() { if let Some(next_id) = self.hop_ids[i] { - if cur_id == *source && next_id == *target { + if cur_id == candidate.source() && Some(next_id) == candidate.target() { return 0; } cur_id = next_id; @@ -2812,7 +3183,7 @@ mod tests { use crate::routing::utxo::UtxoResult; 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, RouteParameters}; + DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE, RouteParameters, CandidateRouteHop, PublicHopCandidate}; 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; @@ -6117,8 +6488,8 @@ mod tests { } 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 channel_penalty_msat(&self, candidate: &CandidateRouteHop, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 { + if candidate.short_channel_id() == Some(self.short_channel_id) { u64::max_value() } else { 0 } } } @@ -6133,8 +6504,8 @@ mod tests { 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 channel_penalty_msat(&self, candidate: &CandidateRouteHop, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 { + if candidate.target() == Some(self.node_id) { u64::max_value() } else { 0 } } } @@ -6622,26 +6993,32 @@ mod tests { }; scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123); scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456); - assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage, &scorer_params), 456); + let network_graph = network_graph.read_only(); + let channels = network_graph.channels(); + let channel = channels.get(&5).unwrap(); + let info = channel.as_directed_from(&NodeId::from_pubkey(&nodes[3])).unwrap(); + let candidate: CandidateRouteHop = CandidateRouteHop::PublicHop(PublicHopCandidate { + info: info.0, + short_channel_id: 5, + }); + assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &scorer_params), 456); // Then check we can get a normal route let payment_params = PaymentParameters::from_node_id(nodes[10], 42); let route_params = RouteParameters::from_payment_params_and_value( payment_params, 100); - let route = get_route(&our_id, &route_params, &network_graph.read_only(), None, + let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes); assert!(route.is_ok()); // Then check that we can't get a route if we ban an intermediate node. scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3])); - let route = get_route(&our_id, &route_params, &network_graph.read_only(), None, - Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes); + let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes); assert!(route.is_err()); // Finally make sure we can route again, when we remove the ban. scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3])); - let route = get_route(&our_id, &route_params, &network_graph.read_only(), None, - Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes); + let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes); assert!(route.is_ok()); } @@ -7917,6 +8294,7 @@ mod tests { pub(crate) mod bench_utils { use super::*; use std::fs::File; + use std::time::Duration; use bitcoin::hashes::Hash; use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey}; @@ -8065,10 +8443,10 @@ pub(crate) mod bench_utils { if let Ok(route) = route_res { for path in route.paths { if seed & 0x80 == 0 { - scorer.payment_path_successful(&path); + scorer.payment_path_successful(&path, Duration::ZERO); } else { let short_channel_id = path.hops[path.hops.len() / 2].short_channel_id; - scorer.payment_path_failed(&path, short_channel_id); + scorer.payment_path_failed(&path, short_channel_id, Duration::ZERO); } seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0; }