1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The router finds paths within a [`NetworkGraph`] for a payment.
12 use bitcoin::secp256k1::{PublicKey, Secp256k1, self};
14 use crate::blinded_path::{BlindedHop, BlindedPath, Direction, IntroductionNode};
15 use crate::blinded_path::message;
16 use crate::blinded_path::payment::{ForwardTlvs, PaymentConstraints, PaymentRelay, ReceiveTlvs, self};
17 use crate::ln::{PaymentHash, PaymentPreimage};
18 use crate::ln::channel_state::ChannelDetails;
19 use crate::ln::channelmanager::{PaymentId, MIN_FINAL_CLTV_EXPIRY_DELTA, RecipientOnionFields};
20 use crate::ln::features::{BlindedHopFeatures, Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures};
21 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
22 use crate::ln::onion_utils;
23 use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice};
24 use crate::onion_message::messenger::{DefaultMessageRouter, Destination, MessageRouter, OnionMessagePath};
25 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
26 use crate::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp};
27 use crate::sign::EntropySource;
28 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
29 use crate::util::logger::{Level, Logger};
30 use crate::crypto::chacha20::ChaCha20;
33 use crate::prelude::*;
34 use alloc::collections::BinaryHeap;
38 /// A [`Router`] implemented using [`find_route`].
42 /// Implements [`MessageRouter`] by delegating to [`DefaultMessageRouter`]. See those docs for
43 /// privacy implications.
44 pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>> + Clone, L: Deref, ES: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> where
46 S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
47 ES::Target: EntropySource,
54 message_router: DefaultMessageRouter<G, L, ES>,
57 impl<G: Deref<Target = NetworkGraph<L>> + Clone, L: Deref, ES: Deref + Clone, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> DefaultRouter<G, L, ES, S, SP, Sc> where
59 S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
60 ES::Target: EntropySource,
62 /// Creates a new router.
63 pub fn new(network_graph: G, logger: L, entropy_source: ES, scorer: S, score_params: SP) -> Self {
64 let message_router = DefaultMessageRouter::new(network_graph.clone(), entropy_source.clone());
65 Self { network_graph, logger, entropy_source, scorer, score_params, message_router }
69 impl<G: Deref<Target = NetworkGraph<L>> + Clone, L: Deref, ES: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> Router for DefaultRouter<G, L, ES, S, SP, Sc> where
71 S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
72 ES::Target: EntropySource,
77 params: &RouteParameters,
78 first_hops: Option<&[&ChannelDetails]>,
79 inflight_htlcs: InFlightHtlcs
80 ) -> Result<Route, LightningError> {
81 let random_seed_bytes = self.entropy_source.get_secure_random_bytes();
83 payer, params, &self.network_graph, first_hops, &*self.logger,
84 &ScorerAccountingForInFlightHtlcs::new(self.scorer.read_lock(), &inflight_htlcs),
90 fn create_blinded_payment_paths<
91 T: secp256k1::Signing + secp256k1::Verification
93 &self, recipient: PublicKey, first_hops: Vec<ChannelDetails>, tlvs: ReceiveTlvs,
94 amount_msats: u64, secp_ctx: &Secp256k1<T>
95 ) -> Result<Vec<(BlindedPayInfo, BlindedPath)>, ()> {
96 // Limit the number of blinded paths that are computed.
97 const MAX_PAYMENT_PATHS: usize = 3;
99 // Ensure peers have at least three channels so that it is more difficult to infer the
100 // recipient's node_id.
101 const MIN_PEER_CHANNELS: usize = 3;
103 let network_graph = self.network_graph.deref().read_only();
104 let paths = first_hops.into_iter()
105 .filter(|details| details.counterparty.features.supports_route_blinding())
106 .filter(|details| amount_msats <= details.inbound_capacity_msat)
107 .filter(|details| amount_msats >= details.inbound_htlc_minimum_msat.unwrap_or(0))
108 .filter(|details| amount_msats <= details.inbound_htlc_maximum_msat.unwrap_or(u64::MAX))
109 .filter(|details| network_graph
110 .node(&NodeId::from_pubkey(&details.counterparty.node_id))
111 .map(|node_info| node_info.channels.len() >= MIN_PEER_CHANNELS)
114 .filter_map(|details| {
115 let short_channel_id = match details.get_inbound_payment_scid() {
116 Some(short_channel_id) => short_channel_id,
119 let payment_relay: PaymentRelay = match details.counterparty.forwarding_info {
120 Some(forwarding_info) => match forwarding_info.try_into() {
121 Ok(payment_relay) => payment_relay,
122 Err(()) => return None,
127 let cltv_expiry_delta = payment_relay.cltv_expiry_delta as u32;
128 let payment_constraints = PaymentConstraints {
129 max_cltv_expiry: tlvs.payment_constraints.max_cltv_expiry + cltv_expiry_delta,
130 htlc_minimum_msat: details.inbound_htlc_minimum_msat.unwrap_or(0),
132 Some(payment::ForwardNode {
137 features: BlindedHopFeatures::empty(),
139 node_id: details.counterparty.node_id,
140 htlc_maximum_msat: details.inbound_htlc_maximum_msat.unwrap_or(u64::MAX),
143 .map(|forward_node| {
144 BlindedPath::new_for_payment(
145 &[forward_node], recipient, tlvs.clone(), u64::MAX, MIN_FINAL_CLTV_EXPIRY_DELTA,
146 &*self.entropy_source, secp_ctx
149 .take(MAX_PAYMENT_PATHS)
150 .collect::<Result<Vec<_>, _>>();
153 Ok(paths) if !paths.is_empty() => Ok(paths),
155 if network_graph.nodes().contains_key(&NodeId::from_pubkey(&recipient)) {
156 BlindedPath::one_hop_for_payment(
157 recipient, tlvs, MIN_FINAL_CLTV_EXPIRY_DELTA, &*self.entropy_source, secp_ctx
158 ).map(|path| vec![path])
167 impl< G: Deref<Target = NetworkGraph<L>> + Clone, L: Deref, ES: Deref, S: Deref, SP: Sized, Sc: ScoreLookUp<ScoreParams = SP>> MessageRouter for DefaultRouter<G, L, ES, S, SP, Sc> where
169 S::Target: for <'a> LockableScore<'a, ScoreLookUp = Sc>,
170 ES::Target: EntropySource,
173 &self, sender: PublicKey, peers: Vec<PublicKey>, destination: Destination
174 ) -> Result<OnionMessagePath, ()> {
175 self.message_router.find_path(sender, peers, destination)
178 fn create_blinded_paths<
179 T: secp256k1::Signing + secp256k1::Verification
181 &self, recipient: PublicKey, peers: Vec<PublicKey>, secp_ctx: &Secp256k1<T>,
182 ) -> Result<Vec<BlindedPath>, ()> {
183 self.message_router.create_blinded_paths(recipient, peers, secp_ctx)
186 fn create_compact_blinded_paths<
187 T: secp256k1::Signing + secp256k1::Verification
189 &self, recipient: PublicKey, peers: Vec<message::ForwardNode>, secp_ctx: &Secp256k1<T>,
190 ) -> Result<Vec<BlindedPath>, ()> {
191 self.message_router.create_compact_blinded_paths(recipient, peers, secp_ctx)
195 /// A trait defining behavior for routing a payment.
196 pub trait Router: MessageRouter {
197 /// Finds a [`Route`] for a payment between the given `payer` and a payee.
199 /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
200 /// and [`RouteParameters::final_value_msat`], respectively.
202 &self, payer: &PublicKey, route_params: &RouteParameters,
203 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
204 ) -> Result<Route, LightningError>;
206 /// Finds a [`Route`] for a payment between the given `payer` and a payee.
208 /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
209 /// and [`RouteParameters::final_value_msat`], respectively.
211 /// Includes a [`PaymentHash`] and a [`PaymentId`] to be able to correlate the request with a specific
213 fn find_route_with_id(
214 &self, payer: &PublicKey, route_params: &RouteParameters,
215 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs,
216 _payment_hash: PaymentHash, _payment_id: PaymentId
217 ) -> Result<Route, LightningError> {
218 self.find_route(payer, route_params, first_hops, inflight_htlcs)
221 /// Creates [`BlindedPath`]s for payment to the `recipient` node. The channels in `first_hops`
222 /// are assumed to be with the `recipient`'s peers. The payment secret and any constraints are
224 fn create_blinded_payment_paths<
225 T: secp256k1::Signing + secp256k1::Verification
227 &self, recipient: PublicKey, first_hops: Vec<ChannelDetails>, tlvs: ReceiveTlvs,
228 amount_msats: u64, secp_ctx: &Secp256k1<T>
229 ) -> Result<Vec<(BlindedPayInfo, BlindedPath)>, ()>;
232 /// [`ScoreLookUp`] implementation that factors in in-flight HTLC liquidity.
234 /// Useful for custom [`Router`] implementations to wrap their [`ScoreLookUp`] on-the-fly when calling
237 /// [`ScoreLookUp`]: crate::routing::scoring::ScoreLookUp
238 pub struct ScorerAccountingForInFlightHtlcs<'a, S: Deref> where S::Target: ScoreLookUp {
240 // Maps a channel's short channel id and its direction to the liquidity used up.
241 inflight_htlcs: &'a InFlightHtlcs,
243 impl<'a, S: Deref> ScorerAccountingForInFlightHtlcs<'a, S> where S::Target: ScoreLookUp {
244 /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
245 pub fn new(scorer: S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
246 ScorerAccountingForInFlightHtlcs {
253 impl<'a, S: Deref> ScoreLookUp for ScorerAccountingForInFlightHtlcs<'a, S> where S::Target: ScoreLookUp {
254 type ScoreParams = <S::Target as ScoreLookUp>::ScoreParams;
255 fn channel_penalty_msat(&self, candidate: &CandidateRouteHop, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 {
256 let target = match candidate.target() {
257 Some(target) => target,
258 None => return self.scorer.channel_penalty_msat(candidate, usage, score_params),
260 let short_channel_id = match candidate.short_channel_id() {
261 Some(short_channel_id) => short_channel_id,
262 None => return self.scorer.channel_penalty_msat(candidate, usage, score_params),
264 let source = candidate.source();
265 if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
266 &source, &target, short_channel_id
268 let usage = ChannelUsage {
269 inflight_htlc_msat: usage.inflight_htlc_msat.saturating_add(used_liquidity),
273 self.scorer.channel_penalty_msat(candidate, usage, score_params)
275 self.scorer.channel_penalty_msat(candidate, usage, score_params)
280 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
281 /// in-use channel liquidity.
283 pub struct InFlightHtlcs(
284 // A map with liquidity value (in msat) keyed by a short channel id and the direction the HTLC
285 // is traveling in. The direction boolean is determined by checking if the HTLC source's public
286 // key is less than its destination. See `InFlightHtlcs::used_liquidity_msat` for more
288 HashMap<(u64, bool), u64>
292 /// Constructs an empty `InFlightHtlcs`.
293 pub fn new() -> Self { InFlightHtlcs(new_hash_map()) }
295 /// Takes in a path with payer's node id and adds the path's details to `InFlightHtlcs`.
296 pub fn process_path(&mut self, path: &Path, payer_node_id: PublicKey) {
297 if path.hops.is_empty() { return };
299 let mut cumulative_msat = 0;
300 if let Some(tail) = &path.blinded_tail {
301 cumulative_msat += tail.final_value_msat;
304 // total_inflight_map needs to be direction-sensitive when keeping track of the HTLC value
305 // that is held up. However, the `hops` array, which is a path returned by `find_route` in
306 // the router excludes the payer node. In the following lines, the payer's information is
307 // hardcoded with an inflight value of 0 so that we can correctly represent the first hop
308 // in our sliding window of two.
309 let reversed_hops_with_payer = path.hops.iter().rev().skip(1)
310 .map(|hop| hop.pubkey)
311 .chain(core::iter::once(payer_node_id));
313 // Taking the reversed vector from above, we zip it with just the reversed hops list to
314 // work "backwards" of the given path, since the last hop's `fee_msat` actually represents
315 // the total amount sent.
316 for (next_hop, prev_hop) in path.hops.iter().rev().zip(reversed_hops_with_payer) {
317 cumulative_msat += next_hop.fee_msat;
319 .entry((next_hop.short_channel_id, NodeId::from_pubkey(&prev_hop) < NodeId::from_pubkey(&next_hop.pubkey)))
320 .and_modify(|used_liquidity_msat| *used_liquidity_msat += cumulative_msat)
321 .or_insert(cumulative_msat);
325 /// Adds a known HTLC given the public key of the HTLC source, target, and short channel
327 pub fn add_inflight_htlc(&mut self, source: &NodeId, target: &NodeId, channel_scid: u64, used_msat: u64){
329 .entry((channel_scid, source < target))
330 .and_modify(|used_liquidity_msat| *used_liquidity_msat += used_msat)
331 .or_insert(used_msat);
334 /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
336 pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
337 self.0.get(&(channel_scid, source < target)).map(|v| *v)
341 impl Writeable for InFlightHtlcs {
342 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
345 impl Readable for InFlightHtlcs {
346 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
347 let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
348 Ok(Self(infight_map))
352 /// A hop in a route, and additional metadata about it. "Hop" is defined as a node and the channel
353 /// that leads to it.
354 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
355 pub struct RouteHop {
356 /// The node_id of the node at this hop.
357 pub pubkey: PublicKey,
358 /// The node_announcement features of the node at this hop. For the last hop, these may be
359 /// amended to match the features present in the invoice this node generated.
360 pub node_features: NodeFeatures,
361 /// The channel that should be used from the previous hop to reach this node.
362 pub short_channel_id: u64,
363 /// The channel_announcement features of the channel that should be used from the previous hop
364 /// to reach this node.
365 pub channel_features: ChannelFeatures,
366 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
367 /// If this is the last hop in [`Path::hops`]:
368 /// * if we're sending to a [`BlindedPath`], this is the fee paid for use of the entire blinded path
369 /// * otherwise, this is the full value of this [`Path`]'s part of the payment
371 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
373 /// The CLTV delta added for this hop.
374 /// If this is the last hop in [`Path::hops`]:
375 /// * if we're sending to a [`BlindedPath`], this is the CLTV delta for the entire blinded path
376 /// * otherwise, this is the CLTV delta expected at the destination
378 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
379 pub cltv_expiry_delta: u32,
380 /// Indicates whether this hop is possibly announced in the public network graph.
382 /// Will be `true` if there is a possibility that the channel is publicly known, i.e., if we
383 /// either know for sure it's announced in the public graph, or if any public channels exist
384 /// for which the given `short_channel_id` could be an alias for. Will be `false` if we believe
385 /// the channel to be unannounced.
387 /// Will be `true` for objects serialized with LDK version 0.0.116 and before.
388 pub maybe_announced_channel: bool,
391 impl_writeable_tlv_based!(RouteHop, {
392 (0, pubkey, required),
393 (1, maybe_announced_channel, (default_value, true)),
394 (2, node_features, required),
395 (4, short_channel_id, required),
396 (6, channel_features, required),
397 (8, fee_msat, required),
398 (10, cltv_expiry_delta, required),
401 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
402 /// their [`Bolt12Invoice`].
404 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
405 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
406 pub struct BlindedTail {
407 /// The hops of the [`BlindedPath`] provided by the recipient.
409 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
410 pub hops: Vec<BlindedHop>,
411 /// The blinding point of the [`BlindedPath`] provided by the recipient.
413 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
414 pub blinding_point: PublicKey,
415 /// Excess CLTV delta added to the recipient's CLTV expiry to deter intermediate nodes from
416 /// inferring the destination. May be 0.
417 pub excess_final_cltv_expiry_delta: u32,
418 /// The total amount paid on this [`Path`], excluding the fees.
419 pub final_value_msat: u64,
422 impl_writeable_tlv_based!(BlindedTail, {
423 (0, hops, required_vec),
424 (2, blinding_point, required),
425 (4, excess_final_cltv_expiry_delta, required),
426 (6, final_value_msat, required),
429 /// A path in a [`Route`] to the payment recipient. Must always be at least length one.
430 /// If no [`Path::blinded_tail`] is present, then [`Path::hops`] length may be up to 19.
431 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
433 /// The list of unblinded hops in this [`Path`]. Must be at least length one.
434 pub hops: Vec<RouteHop>,
435 /// The blinded path at which this path terminates, if we're sending to one, and its metadata.
436 pub blinded_tail: Option<BlindedTail>,
440 /// Gets the fees for a given path, excluding any excess paid to the recipient.
441 pub fn fee_msat(&self) -> u64 {
442 match &self.blinded_tail {
443 Some(_) => self.hops.iter().map(|hop| hop.fee_msat).sum::<u64>(),
445 // Do not count last hop of each path since that's the full value of the payment
446 self.hops.split_last().map_or(0,
447 |(_, path_prefix)| path_prefix.iter().map(|hop| hop.fee_msat).sum())
452 /// Gets the total amount paid on this [`Path`], excluding the fees.
453 pub fn final_value_msat(&self) -> u64 {
454 match &self.blinded_tail {
455 Some(blinded_tail) => blinded_tail.final_value_msat,
456 None => self.hops.last().map_or(0, |hop| hop.fee_msat)
460 /// Gets the final hop's CLTV expiry delta.
461 pub fn final_cltv_expiry_delta(&self) -> Option<u32> {
462 match &self.blinded_tail {
464 None => self.hops.last().map(|hop| hop.cltv_expiry_delta)
469 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
470 /// it can take multiple paths. Each path is composed of one or more hops through the network.
471 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
473 /// The list of [`Path`]s taken for a single (potentially-)multi-part payment. If no
474 /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
476 pub paths: Vec<Path>,
477 /// The `route_params` parameter passed to [`find_route`].
479 /// This is used by `ChannelManager` to track information which may be required for retries.
481 /// Will be `None` for objects serialized with LDK versions prior to 0.0.117.
482 pub route_params: Option<RouteParameters>,
486 /// Returns the total amount of fees paid on this [`Route`].
488 /// For objects serialized with LDK 0.0.117 and after, this includes any extra payment made to
489 /// the recipient, which can happen in excess of the amount passed to [`find_route`] via
490 /// [`RouteParameters::final_value_msat`], if we had to reach the [`htlc_minimum_msat`] limits.
492 /// [`htlc_minimum_msat`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
493 pub fn get_total_fees(&self) -> u64 {
494 let overpaid_value_msat = self.route_params.as_ref()
495 .map_or(0, |p| self.get_total_amount().saturating_sub(p.final_value_msat));
496 overpaid_value_msat + self.paths.iter().map(|path| path.fee_msat()).sum::<u64>()
499 /// Returns the total amount paid on this [`Route`], excluding the fees.
501 /// Might be more than requested as part of the given [`RouteParameters::final_value_msat`] if
502 /// we had to reach the [`htlc_minimum_msat`] limits.
504 /// [`htlc_minimum_msat`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md#the-channel_update-message
505 pub fn get_total_amount(&self) -> u64 {
506 self.paths.iter().map(|path| path.final_value_msat()).sum()
510 impl fmt::Display for Route {
511 fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
512 log_route!(self).fmt(f)
516 const SERIALIZATION_VERSION: u8 = 1;
517 const MIN_SERIALIZATION_VERSION: u8 = 1;
519 impl Writeable for Route {
520 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
521 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
522 (self.paths.len() as u64).write(writer)?;
523 let mut blinded_tails = Vec::new();
524 for (idx, path) in self.paths.iter().enumerate() {
525 (path.hops.len() as u8).write(writer)?;
526 for hop in path.hops.iter() {
529 if let Some(blinded_tail) = &path.blinded_tail {
530 if blinded_tails.is_empty() {
531 blinded_tails = Vec::with_capacity(path.hops.len());
533 blinded_tails.push(None);
536 blinded_tails.push(Some(blinded_tail));
537 } else if !blinded_tails.is_empty() { blinded_tails.push(None); }
539 write_tlv_fields!(writer, {
540 // For compatibility with LDK versions prior to 0.0.117, we take the individual
541 // RouteParameters' fields and reconstruct them on read.
542 (1, self.route_params.as_ref().map(|p| &p.payment_params), option),
543 (2, blinded_tails, optional_vec),
544 (3, self.route_params.as_ref().map(|p| p.final_value_msat), option),
545 (5, self.route_params.as_ref().and_then(|p| p.max_total_routing_fee_msat), option),
551 impl Readable for Route {
552 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
553 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
554 let path_count: u64 = Readable::read(reader)?;
555 if path_count == 0 { return Err(DecodeError::InvalidValue); }
556 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
557 let mut min_final_cltv_expiry_delta = u32::max_value();
558 for _ in 0..path_count {
559 let hop_count: u8 = Readable::read(reader)?;
560 let mut hops: Vec<RouteHop> = Vec::with_capacity(hop_count as usize);
561 for _ in 0..hop_count {
562 hops.push(Readable::read(reader)?);
564 if hops.is_empty() { return Err(DecodeError::InvalidValue); }
565 min_final_cltv_expiry_delta =
566 cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
567 paths.push(Path { hops, blinded_tail: None });
569 _init_and_read_len_prefixed_tlv_fields!(reader, {
570 (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
571 (2, blinded_tails, optional_vec),
572 (3, final_value_msat, option),
573 (5, max_total_routing_fee_msat, option)
575 let blinded_tails = blinded_tails.unwrap_or(Vec::new());
576 if blinded_tails.len() != 0 {
577 if blinded_tails.len() != paths.len() { return Err(DecodeError::InvalidValue) }
578 for (path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
579 path.blinded_tail = blinded_tail_opt;
583 // If we previously wrote the corresponding fields, reconstruct RouteParameters.
584 let route_params = match (payment_params, final_value_msat) {
585 (Some(payment_params), Some(final_value_msat)) => {
586 Some(RouteParameters { payment_params, final_value_msat, max_total_routing_fee_msat })
591 Ok(Route { paths, route_params })
595 /// Parameters needed to find a [`Route`].
597 /// Passed to [`find_route`] and [`build_route_from_hops`].
598 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
599 pub struct RouteParameters {
600 /// The parameters of the failed payment path.
601 pub payment_params: PaymentParameters,
603 /// The amount in msats sent on the failed payment path.
604 pub final_value_msat: u64,
606 /// The maximum total fees, in millisatoshi, that may accrue during route finding.
608 /// This limit also applies to the total fees that may arise while retrying failed payment
611 /// Note that values below a few sats may result in some paths being spuriously ignored.
612 pub max_total_routing_fee_msat: Option<u64>,
615 impl RouteParameters {
616 /// Constructs [`RouteParameters`] from the given [`PaymentParameters`] and a payment amount.
618 /// [`Self::max_total_routing_fee_msat`] defaults to 1% of the payment amount + 50 sats
619 pub fn from_payment_params_and_value(payment_params: PaymentParameters, final_value_msat: u64) -> Self {
620 Self { payment_params, final_value_msat, max_total_routing_fee_msat: Some(final_value_msat / 100 + 50_000) }
623 /// Sets the maximum number of hops that can be included in a payment path, based on the provided
624 /// [`RecipientOnionFields`] and blinded paths.
625 pub fn set_max_path_length(
626 &mut self, recipient_onion: &RecipientOnionFields, is_keysend: bool, best_block_height: u32
627 ) -> Result<(), ()> {
628 let keysend_preimage_opt = is_keysend.then(|| PaymentPreimage([42; 32]));
629 onion_utils::set_max_path_length(
630 self, recipient_onion, keysend_preimage_opt, best_block_height
635 impl Writeable for RouteParameters {
636 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
637 write_tlv_fields!(writer, {
638 (0, self.payment_params, required),
639 (1, self.max_total_routing_fee_msat, option),
640 (2, self.final_value_msat, required),
641 // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
642 // `RouteParameters` directly. For compatibility, we write it here.
643 (4, self.payment_params.payee.final_cltv_expiry_delta(), option),
649 impl Readable for RouteParameters {
650 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
651 _init_and_read_len_prefixed_tlv_fields!(reader, {
652 (0, payment_params, (required: ReadableArgs, 0)),
653 (1, max_total_routing_fee_msat, option),
654 (2, final_value_msat, required),
655 (4, final_cltv_delta, option),
657 let mut payment_params: PaymentParameters = payment_params.0.unwrap();
658 if let Payee::Clear { ref mut final_cltv_expiry_delta, .. } = payment_params.payee {
659 if final_cltv_expiry_delta == &0 {
660 *final_cltv_expiry_delta = final_cltv_delta.ok_or(DecodeError::InvalidValue)?;
665 final_value_msat: final_value_msat.0.unwrap(),
666 max_total_routing_fee_msat,
671 /// Maximum total CTLV difference we allow for a full payment path.
672 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
674 /// Maximum number of paths we allow an (MPP) payment to have.
675 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
676 // limits, but for now more than 10 paths likely carries too much one-path failure.
677 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
679 const DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF: u8 = 2;
681 // The median hop CLTV expiry delta currently seen in the network.
682 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
684 /// Estimated maximum number of hops that can be included in a payment path. May be inaccurate if
685 /// payment metadata, custom TLVs, or blinded paths are included in the payment.
686 // During routing, we only consider paths shorter than our maximum length estimate.
687 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
688 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
689 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
691 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
692 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
693 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
694 // (payment_secret and total_msat) = 93 bytes for the final hop.
695 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
696 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
697 pub const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
699 /// Information used to route a payment.
700 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
701 pub struct PaymentParameters {
702 /// Information about the payee, such as their features and route hints for their channels.
705 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
706 pub expiry_time: Option<u64>,
708 /// The maximum total CLTV delta we accept for the route.
709 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
710 pub max_total_cltv_expiry_delta: u32,
712 /// The maximum number of paths that may be used by (MPP) payments.
713 /// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
714 pub max_path_count: u8,
716 /// The maximum number of [`Path::hops`] in any returned path.
717 /// Defaults to [`MAX_PATH_LENGTH_ESTIMATE`].
718 pub max_path_length: u8,
720 /// Selects the maximum share of a channel's total capacity which will be sent over a channel,
721 /// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
722 /// a lower value prefers to send larger MPP parts, potentially saturating channels and
723 /// increasing failure probability for those paths.
725 /// Note that this restriction will be relaxed during pathfinding after paths which meet this
726 /// restriction have been found. While paths which meet this criteria will be searched for, it
727 /// is ultimately up to the scorer to select them over other paths.
729 /// A value of 0 will allow payments up to and including a channel's total announced usable
730 /// capacity, a value of one will only use up to half its capacity, two 1/4, etc.
733 pub max_channel_saturation_power_of_half: u8,
735 /// A list of SCIDs which this payment was previously attempted over and which caused the
736 /// payment to fail. Future attempts for the same payment shouldn't be relayed through any of
738 pub previously_failed_channels: Vec<u64>,
740 /// A list of indices corresponding to blinded paths in [`Payee::Blinded::route_hints`] which this
741 /// payment was previously attempted over and which caused the payment to fail. Future attempts
742 /// for the same payment shouldn't be relayed through any of these blinded paths.
743 pub previously_failed_blinded_path_idxs: Vec<u64>,
746 impl Writeable for PaymentParameters {
747 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
748 let mut clear_hints = &vec![];
749 let mut blinded_hints = &vec![];
751 Payee::Clear { route_hints, .. } => clear_hints = route_hints,
752 Payee::Blinded { route_hints, .. } => blinded_hints = route_hints,
754 write_tlv_fields!(writer, {
755 (0, self.payee.node_id(), option),
756 (1, self.max_total_cltv_expiry_delta, required),
757 (2, self.payee.features(), option),
758 (3, self.max_path_count, required),
759 (4, *clear_hints, required_vec),
760 (5, self.max_channel_saturation_power_of_half, required),
761 (6, self.expiry_time, option),
762 (7, self.previously_failed_channels, required_vec),
763 (8, *blinded_hints, optional_vec),
764 (9, self.payee.final_cltv_expiry_delta(), option),
765 (11, self.previously_failed_blinded_path_idxs, required_vec),
766 (13, self.max_path_length, required),
772 impl ReadableArgs<u32> for PaymentParameters {
773 fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
774 _init_and_read_len_prefixed_tlv_fields!(reader, {
775 (0, payee_pubkey, option),
776 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
777 (2, features, (option: ReadableArgs, payee_pubkey.is_some())),
778 (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
779 (4, clear_route_hints, required_vec),
780 (5, max_channel_saturation_power_of_half, (default_value, DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF)),
781 (6, expiry_time, option),
782 (7, previously_failed_channels, optional_vec),
783 (8, blinded_route_hints, optional_vec),
784 (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
785 (11, previously_failed_blinded_path_idxs, optional_vec),
786 (13, max_path_length, (default_value, MAX_PATH_LENGTH_ESTIMATE)),
788 let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
789 let payee = if blinded_route_hints.len() != 0 {
790 if clear_route_hints.len() != 0 || payee_pubkey.is_some() { return Err(DecodeError::InvalidValue) }
792 route_hints: blinded_route_hints,
793 features: features.and_then(|f: Features| f.bolt12()),
797 route_hints: clear_route_hints,
798 node_id: payee_pubkey.ok_or(DecodeError::InvalidValue)?,
799 features: features.and_then(|f| f.bolt11()),
800 final_cltv_expiry_delta: final_cltv_expiry_delta.0.unwrap(),
804 max_total_cltv_expiry_delta: _init_tlv_based_struct_field!(max_total_cltv_expiry_delta, (default_value, unused)),
805 max_path_count: _init_tlv_based_struct_field!(max_path_count, (default_value, unused)),
807 max_channel_saturation_power_of_half: _init_tlv_based_struct_field!(max_channel_saturation_power_of_half, (default_value, unused)),
809 previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
810 previously_failed_blinded_path_idxs: previously_failed_blinded_path_idxs.unwrap_or(Vec::new()),
811 max_path_length: _init_tlv_based_struct_field!(max_path_length, (default_value, unused)),
817 impl PaymentParameters {
818 /// Creates a payee with the node id of the given `pubkey`.
820 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
822 pub fn from_node_id(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
824 payee: Payee::Clear { node_id: payee_pubkey, route_hints: vec![], features: None, final_cltv_expiry_delta },
826 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
827 max_path_count: DEFAULT_MAX_PATH_COUNT,
828 max_path_length: MAX_PATH_LENGTH_ESTIMATE,
829 max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
830 previously_failed_channels: Vec::new(),
831 previously_failed_blinded_path_idxs: Vec::new(),
835 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
837 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
840 /// Note that MPP keysend is not widely supported yet. The `allow_mpp` lets you choose
841 /// whether your router will be allowed to find a multi-part route for this payment. If you
842 /// set `allow_mpp` to true, you should ensure a payment secret is set on send, likely via
843 /// [`RecipientOnionFields::secret_only`].
845 /// [`RecipientOnionFields::secret_only`]: crate::ln::channelmanager::RecipientOnionFields::secret_only
846 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32, allow_mpp: bool) -> Self {
847 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta)
848 .with_bolt11_features(Bolt11InvoiceFeatures::for_keysend(allow_mpp))
849 .expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
852 /// Creates parameters for paying to a blinded payee from the provided invoice. Sets
853 /// [`Payee::Blinded::route_hints`], [`Payee::Blinded::features`], and
854 /// [`PaymentParameters::expiry_time`].
855 pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
856 Self::blinded(invoice.payment_paths().to_vec())
857 .with_bolt12_features(invoice.invoice_features().clone()).unwrap()
858 .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
861 /// Creates parameters for paying to a blinded payee from the provided blinded route hints.
862 pub fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
864 payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
866 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
867 max_path_count: DEFAULT_MAX_PATH_COUNT,
868 max_path_length: MAX_PATH_LENGTH_ESTIMATE,
869 max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
870 previously_failed_channels: Vec::new(),
871 previously_failed_blinded_path_idxs: Vec::new(),
875 /// Includes the payee's features. Errors if the parameters were not initialized with
876 /// [`PaymentParameters::from_bolt12_invoice`].
878 /// This is not exported to bindings users since bindings don't support move semantics
879 pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
881 Payee::Clear { .. } => Err(()),
882 Payee::Blinded { route_hints, .. } =>
883 Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
887 /// Includes the payee's features. Errors if the parameters were initialized with
888 /// [`PaymentParameters::from_bolt12_invoice`].
890 /// This is not exported to bindings users since bindings don't support move semantics
891 pub fn with_bolt11_features(self, features: Bolt11InvoiceFeatures) -> Result<Self, ()> {
893 Payee::Blinded { .. } => Err(()),
894 Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
896 payee: Payee::Clear {
897 route_hints, node_id, features: Some(features), final_cltv_expiry_delta
903 /// Includes hints for routing to the payee. Errors if the parameters were initialized with
904 /// [`PaymentParameters::from_bolt12_invoice`].
906 /// This is not exported to bindings users since bindings don't support move semantics
907 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
909 Payee::Blinded { .. } => Err(()),
910 Payee::Clear { node_id, features, final_cltv_expiry_delta, .. } =>
912 payee: Payee::Clear {
913 route_hints, node_id, features, final_cltv_expiry_delta,
919 /// Includes a payment expiration in seconds relative to the UNIX epoch.
921 /// This is not exported to bindings users since bindings don't support move semantics
922 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
923 Self { expiry_time: Some(expiry_time), ..self }
926 /// Includes a limit for the total CLTV expiry delta which is considered during routing
928 /// This is not exported to bindings users since bindings don't support move semantics
929 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
930 Self { max_total_cltv_expiry_delta, ..self }
933 /// Includes a limit for the maximum number of payment paths that may be used.
935 /// This is not exported to bindings users since bindings don't support move semantics
936 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
937 Self { max_path_count, ..self }
940 /// Includes a limit for the maximum share of a channel's total capacity that can be sent over, as
941 /// a power of 1/2. See [`PaymentParameters::max_channel_saturation_power_of_half`].
943 /// This is not exported to bindings users since bindings don't support move semantics
944 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
945 Self { max_channel_saturation_power_of_half, ..self }
948 pub(crate) fn insert_previously_failed_blinded_path(&mut self, failed_blinded_tail: &BlindedTail) {
949 let mut found_blinded_tail = false;
950 for (idx, (_, path)) in self.payee.blinded_route_hints().iter().enumerate() {
951 if failed_blinded_tail.hops == path.blinded_hops &&
952 failed_blinded_tail.blinding_point == path.blinding_point
954 self.previously_failed_blinded_path_idxs.push(idx as u64);
955 found_blinded_tail = true;
958 debug_assert!(found_blinded_tail);
962 /// The recipient of a payment, differing based on whether they've hidden their identity with route
964 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
966 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
967 /// will be included in the final [`Route`].
969 /// Aggregated routing info and blinded paths, for routing to the payee without knowing their
971 route_hints: Vec<(BlindedPayInfo, BlindedPath)>,
972 /// Features supported by the payee.
974 /// May be set from the payee's invoice. May be `None` if the invoice does not contain any
976 features: Option<Bolt12InvoiceFeatures>,
978 /// The recipient included these route hints in their BOLT11 invoice.
980 /// The node id of the payee.
982 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
983 route_hints: Vec<RouteHint>,
984 /// Features supported by the payee.
986 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
987 /// does not contain any features.
989 /// [`for_keysend`]: PaymentParameters::for_keysend
990 features: Option<Bolt11InvoiceFeatures>,
991 /// The minimum CLTV delta at the end of the route. This value must not be zero.
992 final_cltv_expiry_delta: u32,
997 fn node_id(&self) -> Option<PublicKey> {
999 Self::Clear { node_id, .. } => Some(*node_id),
1003 fn node_features(&self) -> Option<NodeFeatures> {
1005 Self::Clear { features, .. } => features.as_ref().map(|f| f.to_context()),
1006 Self::Blinded { features, .. } => features.as_ref().map(|f| f.to_context()),
1009 fn supports_basic_mpp(&self) -> bool {
1011 Self::Clear { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
1012 Self::Blinded { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
1015 fn features(&self) -> Option<FeaturesRef> {
1017 Self::Clear { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt11(f)),
1018 Self::Blinded { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt12(f)),
1021 fn final_cltv_expiry_delta(&self) -> Option<u32> {
1023 Self::Clear { final_cltv_expiry_delta, .. } => Some(*final_cltv_expiry_delta),
1027 pub(crate) fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
1029 Self::Blinded { route_hints, .. } => &route_hints[..],
1030 Self::Clear { .. } => &[]
1034 fn unblinded_route_hints(&self) -> &[RouteHint] {
1036 Self::Blinded { .. } => &[],
1037 Self::Clear { route_hints, .. } => &route_hints[..]
1042 enum FeaturesRef<'a> {
1043 Bolt11(&'a Bolt11InvoiceFeatures),
1044 Bolt12(&'a Bolt12InvoiceFeatures),
1047 Bolt11(Bolt11InvoiceFeatures),
1048 Bolt12(Bolt12InvoiceFeatures),
1052 fn bolt12(self) -> Option<Bolt12InvoiceFeatures> {
1054 Self::Bolt12(f) => Some(f),
1058 fn bolt11(self) -> Option<Bolt11InvoiceFeatures> {
1060 Self::Bolt11(f) => Some(f),
1066 impl<'a> Writeable for FeaturesRef<'a> {
1067 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1069 Self::Bolt11(f) => Ok(f.write(w)?),
1070 Self::Bolt12(f) => Ok(f.write(w)?),
1075 impl ReadableArgs<bool> for Features {
1076 fn read<R: io::Read>(reader: &mut R, bolt11: bool) -> Result<Self, DecodeError> {
1077 if bolt11 { return Ok(Self::Bolt11(Readable::read(reader)?)) }
1078 Ok(Self::Bolt12(Readable::read(reader)?))
1082 /// A list of hops along a payment path terminating with a channel to the recipient.
1083 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
1084 pub struct RouteHint(pub Vec<RouteHintHop>);
1086 impl Writeable for RouteHint {
1087 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1088 (self.0.len() as u64).write(writer)?;
1089 for hop in self.0.iter() {
1096 impl Readable for RouteHint {
1097 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1098 let hop_count: u64 = Readable::read(reader)?;
1099 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
1100 for _ in 0..hop_count {
1101 hops.push(Readable::read(reader)?);
1107 /// A channel descriptor for a hop along a payment path.
1109 /// While this generally comes from BOLT 11's `r` field, this struct includes more fields than are
1110 /// available in BOLT 11. Thus, encoding and decoding this via `lightning-invoice` is lossy, as
1111 /// fields not supported in BOLT 11 will be stripped.
1112 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
1113 pub struct RouteHintHop {
1114 /// The node_id of the non-target end of the route
1115 pub src_node_id: PublicKey,
1116 /// The short_channel_id of this channel
1117 pub short_channel_id: u64,
1118 /// The fees which must be paid to use this channel
1119 pub fees: RoutingFees,
1120 /// The difference in CLTV values between this node and the next node.
1121 pub cltv_expiry_delta: u16,
1122 /// The minimum value, in msat, which must be relayed to the next hop.
1123 pub htlc_minimum_msat: Option<u64>,
1124 /// The maximum value in msat available for routing with a single HTLC.
1125 pub htlc_maximum_msat: Option<u64>,
1128 impl_writeable_tlv_based!(RouteHintHop, {
1129 (0, src_node_id, required),
1130 (1, htlc_minimum_msat, option),
1131 (2, short_channel_id, required),
1132 (3, htlc_maximum_msat, option),
1133 (4, fees, required),
1134 (6, cltv_expiry_delta, required),
1137 #[derive(Eq, PartialEq)]
1138 #[repr(align(64))] // Force the size to 64 bytes
1139 struct RouteGraphNode {
1142 // The maximum value a yet-to-be-constructed payment path might flow through this node.
1143 // This value is upper-bounded by us by:
1144 // - how much is needed for a path being constructed
1145 // - how much value can channels following this node (up to the destination) can contribute,
1146 // considering their capacity and fees
1147 value_contribution_msat: u64,
1148 total_cltv_delta: u32,
1149 /// The number of hops walked up to this node.
1150 path_length_to_node: u8,
1153 impl cmp::Ord for RouteGraphNode {
1154 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
1155 other.score.cmp(&self.score).then_with(|| other.node_id.cmp(&self.node_id))
1159 impl cmp::PartialOrd for RouteGraphNode {
1160 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
1161 Some(self.cmp(other))
1165 // While RouteGraphNode can be laid out with fewer bytes, performance appears to be improved
1166 // substantially when it is laid out at exactly 64 bytes.
1168 // Thus, we use `#[repr(C)]` on the struct to force a suboptimal layout and check that it stays 64
1170 #[cfg(any(ldk_bench, not(any(test, fuzzing))))]
1171 const _GRAPH_NODE_SMALL: usize = 64 - core::mem::size_of::<RouteGraphNode>();
1172 #[cfg(any(ldk_bench, not(any(test, fuzzing))))]
1173 const _GRAPH_NODE_FIXED_SIZE: usize = core::mem::size_of::<RouteGraphNode>() - 64;
1175 /// A [`CandidateRouteHop::FirstHop`] entry.
1176 #[derive(Clone, Debug)]
1177 pub struct FirstHopCandidate<'a> {
1178 /// Channel details of the first hop
1180 /// [`ChannelDetails::get_outbound_payment_scid`] MUST be `Some` (indicating the channel
1181 /// has been funded and is able to pay), and accessor methods may panic otherwise.
1183 /// [`find_route`] validates this prior to constructing a [`CandidateRouteHop`].
1185 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1186 pub details: &'a ChannelDetails,
1187 /// The node id of the payer, which is also the source side of this candidate route hop.
1189 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1190 pub payer_node_id: &'a NodeId,
1193 /// A [`CandidateRouteHop::PublicHop`] entry.
1194 #[derive(Clone, Debug)]
1195 pub struct PublicHopCandidate<'a> {
1196 /// Information about the channel, including potentially its capacity and
1197 /// direction-specific information.
1199 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1200 pub info: DirectedChannelInfo<'a>,
1201 /// The short channel ID of the channel, i.e. the identifier by which we refer to this
1203 pub short_channel_id: u64,
1206 /// A [`CandidateRouteHop::PrivateHop`] entry.
1207 #[derive(Clone, Debug)]
1208 pub struct PrivateHopCandidate<'a> {
1209 /// Information about the private hop communicated via BOLT 11.
1211 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1212 pub hint: &'a RouteHintHop,
1213 /// Node id of the next hop in BOLT 11 route hint.
1215 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1216 pub target_node_id: &'a NodeId
1219 /// A [`CandidateRouteHop::Blinded`] entry.
1220 #[derive(Clone, Debug)]
1221 pub struct BlindedPathCandidate<'a> {
1222 /// The node id of the introduction node, resolved from either the [`NetworkGraph`] or first
1225 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1226 pub source_node_id: &'a NodeId,
1227 /// Information about the blinded path including the fee, HTLC amount limits, and
1228 /// cryptographic material required to build an HTLC through the given path.
1230 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1231 pub hint: &'a (BlindedPayInfo, BlindedPath),
1232 /// Index of the hint in the original list of blinded hints.
1234 /// This is used to cheaply uniquely identify this blinded path, even though we don't have
1235 /// a short channel ID for this hop.
1239 /// A [`CandidateRouteHop::OneHopBlinded`] entry.
1240 #[derive(Clone, Debug)]
1241 pub struct OneHopBlindedPathCandidate<'a> {
1242 /// The node id of the introduction node, resolved from either the [`NetworkGraph`] or first
1245 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1246 pub source_node_id: &'a NodeId,
1247 /// Information about the blinded path including the fee, HTLC amount limits, and
1248 /// cryptographic material required to build an HTLC terminating with the given path.
1250 /// Note that the [`BlindedPayInfo`] is ignored here.
1252 /// This is not exported to bindings users as lifetimes are not expressible in most languages.
1253 pub hint: &'a (BlindedPayInfo, BlindedPath),
1254 /// Index of the hint in the original list of blinded hints.
1256 /// This is used to cheaply uniquely identify this blinded path, even though we don't have
1257 /// a short channel ID for this hop.
1261 /// A wrapper around the various hop representations.
1263 /// Can be used to examine the properties of a hop,
1264 /// potentially to decide whether to include it in a route.
1265 #[derive(Clone, Debug)]
1266 pub enum CandidateRouteHop<'a> {
1267 /// A hop from the payer, where the outbound liquidity is known.
1268 FirstHop(FirstHopCandidate<'a>),
1269 /// A hop found in the [`ReadOnlyNetworkGraph`].
1270 PublicHop(PublicHopCandidate<'a>),
1271 /// A private hop communicated by the payee, generally via a BOLT 11 invoice.
1273 /// Because BOLT 11 route hints can take multiple hops to get to the destination, this may not
1274 /// terminate at the payee.
1275 PrivateHop(PrivateHopCandidate<'a>),
1276 /// A blinded path which starts with an introduction point and ultimately terminates with the
1279 /// Because we don't know the payee's identity, [`CandidateRouteHop::target`] will return
1280 /// `None` in this state.
1282 /// Because blinded paths are "all or nothing", and we cannot use just one part of a blinded
1283 /// path, the full path is treated as a single [`CandidateRouteHop`].
1284 Blinded(BlindedPathCandidate<'a>),
1285 /// Similar to [`Self::Blinded`], but the path here only has one hop.
1287 /// While we treat this similarly to [`CandidateRouteHop::Blinded`] in many respects (e.g.
1288 /// returning `None` from [`CandidateRouteHop::target`]), in this case we do actually know the
1289 /// payee's identity - it's the introduction point!
1291 /// [`BlindedPayInfo`] provided for 1-hop blinded paths is ignored because it is meant to apply
1292 /// to the hops *between* the introduction node and the destination.
1294 /// This primarily exists to track that we need to included a blinded path at the end of our
1295 /// [`Route`], even though it doesn't actually add an additional hop in the payment.
1296 OneHopBlinded(OneHopBlindedPathCandidate<'a>),
1299 impl<'a> CandidateRouteHop<'a> {
1300 /// Returns the short channel ID for this hop, if one is known.
1302 /// This SCID could be an alias or a globally unique SCID, and thus is only expected to
1303 /// uniquely identify this channel in conjunction with the [`CandidateRouteHop::source`].
1305 /// Returns `Some` as long as the candidate is a [`CandidateRouteHop::PublicHop`], a
1306 /// [`CandidateRouteHop::PrivateHop`] from a BOLT 11 route hint, or a
1307 /// [`CandidateRouteHop::FirstHop`] with a known [`ChannelDetails::get_outbound_payment_scid`]
1308 /// (which is always true for channels which are funded and ready for use).
1310 /// In other words, this should always return `Some` as long as the candidate hop is not a
1311 /// [`CandidateRouteHop::Blinded`] or a [`CandidateRouteHop::OneHopBlinded`].
1313 /// Note that this is deliberately not public as it is somewhat of a footgun because it doesn't
1314 /// define a global namespace.
1316 fn short_channel_id(&self) -> Option<u64> {
1318 CandidateRouteHop::FirstHop(hop) => hop.details.get_outbound_payment_scid(),
1319 CandidateRouteHop::PublicHop(hop) => Some(hop.short_channel_id),
1320 CandidateRouteHop::PrivateHop(hop) => Some(hop.hint.short_channel_id),
1321 CandidateRouteHop::Blinded(_) => None,
1322 CandidateRouteHop::OneHopBlinded(_) => None,
1326 /// Returns the globally unique short channel ID for this hop, if one is known.
1328 /// This only returns `Some` if the channel is public (either our own, or one we've learned
1329 /// from the public network graph), and thus the short channel ID we have for this channel is
1330 /// globally unique and identifies this channel in a global namespace.
1332 pub fn globally_unique_short_channel_id(&self) -> Option<u64> {
1334 CandidateRouteHop::FirstHop(hop) => if hop.details.is_public { hop.details.short_channel_id } else { None },
1335 CandidateRouteHop::PublicHop(hop) => Some(hop.short_channel_id),
1336 CandidateRouteHop::PrivateHop(_) => None,
1337 CandidateRouteHop::Blinded(_) => None,
1338 CandidateRouteHop::OneHopBlinded(_) => None,
1342 // NOTE: This may alloc memory so avoid calling it in a hot code path.
1343 fn features(&self) -> ChannelFeatures {
1345 CandidateRouteHop::FirstHop(hop) => hop.details.counterparty.features.to_context(),
1346 CandidateRouteHop::PublicHop(hop) => hop.info.channel().features.clone(),
1347 CandidateRouteHop::PrivateHop(_) => ChannelFeatures::empty(),
1348 CandidateRouteHop::Blinded(_) => ChannelFeatures::empty(),
1349 CandidateRouteHop::OneHopBlinded(_) => ChannelFeatures::empty(),
1353 /// Returns the required difference in HTLC CLTV expiry between the [`Self::source`] and the
1354 /// next-hop for an HTLC taking this hop.
1356 /// This is the time that the node(s) in this hop have to claim the HTLC on-chain if the
1357 /// next-hop goes on chain with a payment preimage.
1359 pub fn cltv_expiry_delta(&self) -> u32 {
1361 CandidateRouteHop::FirstHop(_) => 0,
1362 CandidateRouteHop::PublicHop(hop) => hop.info.direction().cltv_expiry_delta as u32,
1363 CandidateRouteHop::PrivateHop(hop) => hop.hint.cltv_expiry_delta as u32,
1364 CandidateRouteHop::Blinded(hop) => hop.hint.0.cltv_expiry_delta as u32,
1365 CandidateRouteHop::OneHopBlinded(_) => 0,
1369 /// Returns the minimum amount that can be sent over this hop, in millisatoshis.
1371 pub fn htlc_minimum_msat(&self) -> u64 {
1373 CandidateRouteHop::FirstHop(hop) => hop.details.next_outbound_htlc_minimum_msat,
1374 CandidateRouteHop::PublicHop(hop) => hop.info.direction().htlc_minimum_msat,
1375 CandidateRouteHop::PrivateHop(hop) => hop.hint.htlc_minimum_msat.unwrap_or(0),
1376 CandidateRouteHop::Blinded(hop) => hop.hint.0.htlc_minimum_msat,
1377 CandidateRouteHop::OneHopBlinded { .. } => 0,
1381 /// Returns the fees that must be paid to route an HTLC over this channel.
1383 pub fn fees(&self) -> RoutingFees {
1385 CandidateRouteHop::FirstHop(_) => RoutingFees {
1386 base_msat: 0, proportional_millionths: 0,
1388 CandidateRouteHop::PublicHop(hop) => hop.info.direction().fees,
1389 CandidateRouteHop::PrivateHop(hop) => hop.hint.fees,
1390 CandidateRouteHop::Blinded(hop) => {
1392 base_msat: hop.hint.0.fee_base_msat,
1393 proportional_millionths: hop.hint.0.fee_proportional_millionths
1396 CandidateRouteHop::OneHopBlinded(_) =>
1397 RoutingFees { base_msat: 0, proportional_millionths: 0 },
1401 /// Fetch the effective capacity of this hop.
1403 /// Note that this may be somewhat expensive, so calls to this should be limited and results
1405 fn effective_capacity(&self) -> EffectiveCapacity {
1407 CandidateRouteHop::FirstHop(hop) => EffectiveCapacity::ExactLiquidity {
1408 liquidity_msat: hop.details.next_outbound_htlc_limit_msat,
1410 CandidateRouteHop::PublicHop(hop) => hop.info.effective_capacity(),
1411 CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }, .. }) =>
1412 EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
1413 CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: RouteHintHop { htlc_maximum_msat: None, .. }, .. }) =>
1414 EffectiveCapacity::Infinite,
1415 CandidateRouteHop::Blinded(hop) =>
1416 EffectiveCapacity::HintMaxHTLC { amount_msat: hop.hint.0.htlc_maximum_msat },
1417 CandidateRouteHop::OneHopBlinded(_) => EffectiveCapacity::Infinite,
1421 /// Returns an ID describing the given hop.
1423 /// See the docs on [`CandidateHopId`] for when this is, or is not, unique.
1425 fn id(&self) -> CandidateHopId {
1427 CandidateRouteHop::Blinded(hop) => CandidateHopId::Blinded(hop.hint_idx),
1428 CandidateRouteHop::OneHopBlinded(hop) => CandidateHopId::Blinded(hop.hint_idx),
1429 _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), self.source() < self.target().unwrap())),
1432 fn blinded_path(&self) -> Option<&'a BlindedPath> {
1434 CandidateRouteHop::Blinded(BlindedPathCandidate { hint, .. }) | CandidateRouteHop::OneHopBlinded(OneHopBlindedPathCandidate { hint, .. }) => {
1440 fn blinded_hint_idx(&self) -> Option<usize> {
1442 Self::Blinded(BlindedPathCandidate { hint_idx, .. }) |
1443 Self::OneHopBlinded(OneHopBlindedPathCandidate { hint_idx, .. }) => {
1449 /// Returns the source node id of current hop.
1451 /// Source node id refers to the node forwarding the HTLC through this hop.
1453 /// For [`Self::FirstHop`] we return payer's node id.
1455 pub fn source(&self) -> NodeId {
1457 CandidateRouteHop::FirstHop(hop) => *hop.payer_node_id,
1458 CandidateRouteHop::PublicHop(hop) => *hop.info.source(),
1459 CandidateRouteHop::PrivateHop(hop) => hop.hint.src_node_id.into(),
1460 CandidateRouteHop::Blinded(hop) => *hop.source_node_id,
1461 CandidateRouteHop::OneHopBlinded(hop) => *hop.source_node_id,
1464 /// Returns the target node id of this hop, if known.
1466 /// Target node id refers to the node receiving the HTLC after this hop.
1468 /// For [`Self::Blinded`] we return `None` because the ultimate destination after the blinded
1469 /// path is unknown.
1471 /// For [`Self::OneHopBlinded`] we return `None` because the target is the same as the source,
1472 /// and such a return value would be somewhat nonsensical.
1474 pub fn target(&self) -> Option<NodeId> {
1476 CandidateRouteHop::FirstHop(hop) => Some(hop.details.counterparty.node_id.into()),
1477 CandidateRouteHop::PublicHop(hop) => Some(*hop.info.target()),
1478 CandidateRouteHop::PrivateHop(hop) => Some(*hop.target_node_id),
1479 CandidateRouteHop::Blinded(_) => None,
1480 CandidateRouteHop::OneHopBlinded(_) => None,
1485 /// A unique(ish) identifier for a specific [`CandidateRouteHop`].
1487 /// For blinded paths, this ID is unique only within a given [`find_route`] call.
1489 /// For other hops, because SCIDs between private channels and public channels can conflict, this
1490 /// isn't guaranteed to be unique at all.
1492 /// For our uses, this is generally fine, but it is not public as it is otherwise a rather
1493 /// difficult-to-use API.
1494 #[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)]
1495 enum CandidateHopId {
1496 /// Contains (scid, src_node_id < target_node_id)
1498 /// Index of the blinded route hint in [`Payee::Blinded::route_hints`].
1503 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
1504 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
1506 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
1507 EffectiveCapacity::Infinite => u64::max_value(),
1508 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
1509 EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
1510 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
1511 // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
1512 // expected to have been generated from up-to-date capacity information.
1513 EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
1514 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
1515 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
1519 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
1520 -> bool where I1::Item: PartialEq<I2::Item> {
1522 let a = iter_a.next();
1523 let b = iter_b.next();
1524 if a.is_none() && b.is_none() { return true; }
1525 if a.is_none() || b.is_none() { return false; }
1526 if a.unwrap().ne(&b.unwrap()) { return false; }
1530 /// It's useful to keep track of the hops associated with the fees required to use them,
1531 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
1532 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
1533 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
1535 #[repr(C)] // Force fields to appear in the order we define them.
1536 struct PathBuildingHop<'a> {
1537 candidate: CandidateRouteHop<'a>,
1538 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
1539 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
1540 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
1541 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
1542 /// avoid processing them again.
1543 was_processed: bool,
1544 /// Used to compare channels when choosing the for routing.
1545 /// Includes paying for the use of a hop and the following hops, as well as
1546 /// an estimated cost of reaching this hop.
1547 /// Might get stale when fees are recomputed. Primarily for internal use.
1548 total_fee_msat: u64,
1549 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
1550 /// walk and may be invalid thereafter.
1551 path_htlc_minimum_msat: u64,
1552 /// All penalties incurred from this channel on the way to the destination, as calculated using
1553 /// channel scoring.
1554 path_penalty_msat: u64,
1556 // The last 16 bytes are on the next cache line by default in glibc's malloc. Thus, we should
1557 // only place fields which are not hot there. Luckily, the next three fields are only read if
1558 // we end up on the selected path, and only in the final path layout phase, so we don't care
1559 // too much if reading them is slow.
1563 /// All the fees paid *after* this channel on the way to the destination
1564 next_hops_fee_msat: u64,
1565 /// Fee paid for the use of the current channel (see candidate.fees()).
1566 /// The value will be actually deducted from the counterparty balance on the previous link.
1567 hop_use_fee_msat: u64,
1569 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1570 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
1571 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
1572 // value_contribution_msat, which requires tracking it here. See comments below where it is
1573 // used for more info.
1574 value_contribution_msat: u64,
1577 // Checks that the entries in the `find_route` `dist` map fit in (exactly) two standard x86-64
1578 // cache lines. Sadly, they're not guaranteed to actually lie on a cache line (and in fact,
1579 // generally won't, because at least glibc's malloc will align to a nice, big, round
1580 // boundary...plus 16), but at least it will reduce the amount of data we'll need to load.
1582 // Note that these assertions only pass on somewhat recent rustc, and thus are gated on the
1585 const _NODE_MAP_SIZE_TWO_CACHE_LINES: usize = 128 - core::mem::size_of::<(NodeId, PathBuildingHop)>();
1587 const _NODE_MAP_SIZE_EXACTLY_CACHE_LINES: usize = core::mem::size_of::<(NodeId, PathBuildingHop)>() - 128;
1589 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
1590 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1591 let mut debug_struct = f.debug_struct("PathBuildingHop");
1593 .field("node_id", &self.candidate.target())
1594 .field("short_channel_id", &self.candidate.short_channel_id())
1595 .field("total_fee_msat", &self.total_fee_msat)
1596 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
1597 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
1598 .field("total_fee_msat - (next_hops_fee_msat + hop_use_fee_msat)", &(&self.total_fee_msat - (&self.next_hops_fee_msat + &self.hop_use_fee_msat)))
1599 .field("path_penalty_msat", &self.path_penalty_msat)
1600 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
1601 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
1602 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1603 let debug_struct = debug_struct
1604 .field("value_contribution_msat", &self.value_contribution_msat);
1605 debug_struct.finish()
1609 // Instantiated with a list of hops with correct data in them collected during path finding,
1610 // an instance of this struct should be further modified only via given methods.
1612 struct PaymentPath<'a> {
1613 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
1616 impl<'a> PaymentPath<'a> {
1617 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
1618 fn get_value_msat(&self) -> u64 {
1619 self.hops.last().unwrap().0.fee_msat
1622 fn get_path_penalty_msat(&self) -> u64 {
1623 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
1626 fn get_total_fee_paid_msat(&self) -> u64 {
1627 if self.hops.len() < 1 {
1631 // Can't use next_hops_fee_msat because it gets outdated.
1632 for (i, (hop, _)) in self.hops.iter().enumerate() {
1633 if i != self.hops.len() - 1 {
1634 result += hop.fee_msat;
1640 fn get_cost_msat(&self) -> u64 {
1641 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
1644 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
1645 // to change fees may result in an inconsistency.
1647 // Sometimes we call this function right after constructing a path which is inconsistent in
1648 // that it the value being transferred has decreased while we were doing path finding, leading
1649 // to the fees being paid not lining up with the actual limits.
1651 // Note that this function is not aware of the available_liquidity limit, and thus does not
1652 // support increasing the value being transferred beyond what was selected during the initial
1655 // Returns the amount that this path contributes to the total payment value, which may be greater
1656 // than `value_msat` if we had to overpay to meet the final node's `htlc_minimum_msat`.
1657 fn update_value_and_recompute_fees(&mut self, value_msat: u64) -> u64 {
1658 let mut extra_contribution_msat = 0;
1659 let mut total_fee_paid_msat = 0 as u64;
1660 for i in (0..self.hops.len()).rev() {
1661 let last_hop = i == self.hops.len() - 1;
1663 // For non-last-hop, this value will represent the fees paid on the current hop. It
1664 // will consist of the fees for the use of the next hop, and extra fees to match
1665 // htlc_minimum_msat of the current channel. Last hop is handled separately.
1666 let mut cur_hop_fees_msat = 0;
1668 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
1671 let cur_hop = &mut self.hops.get_mut(i).unwrap().0;
1672 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
1673 cur_hop.path_penalty_msat += extra_contribution_msat;
1674 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
1675 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
1676 // set it too high just to maliciously take more fees by exploiting this
1677 // match htlc_minimum_msat logic.
1678 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
1679 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
1680 // Note that there is a risk that *previous hops* (those closer to us, as we go
1681 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
1683 // This might make us end up with a broken route, although this should be super-rare
1684 // in practice, both because of how healthy channels look like, and how we pick
1685 // channels in add_entry.
1686 // Also, this can't be exploited more heavily than *announce a free path and fail
1688 cur_hop_transferred_amount_msat += extra_fees_msat;
1690 // We remember and return the extra fees on the final hop to allow accounting for
1691 // them in the path's value contribution.
1693 extra_contribution_msat = extra_fees_msat;
1695 total_fee_paid_msat += extra_fees_msat;
1696 cur_hop_fees_msat += extra_fees_msat;
1701 // Final hop is a special case: it usually has just value_msat (by design), but also
1702 // it still could overpay for the htlc_minimum_msat.
1703 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
1705 // Propagate updated fees for the use of the channels to one hop back, where they
1706 // will be actually paid (fee_msat). The last hop is handled above separately.
1707 cur_hop.fee_msat = cur_hop_fees_msat;
1710 // Fee for the use of the current hop which will be deducted on the previous hop.
1711 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
1712 // this channel is free for us.
1714 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
1715 cur_hop.hop_use_fee_msat = new_fee;
1716 total_fee_paid_msat += new_fee;
1718 // It should not be possible because this function is called only to reduce the
1719 // value. In that case, compute_fee was already called with the same fees for
1720 // larger amount and there was no overflow.
1725 value_msat + extra_contribution_msat
1730 /// Calculate the fees required to route the given amount over a channel with the given fees.
1731 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
1732 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1733 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
1737 /// Calculate the fees required to route the given amount over a channel with the given fees,
1738 /// saturating to [`u64::max_value`].
1739 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
1740 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1741 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
1742 .saturating_add(channel_fees.base_msat as u64)
1745 /// The default `features` we assume for a node in a route, when no `features` are known about that
1748 /// Default features are:
1749 /// * variable_length_onion_optional
1750 fn default_node_features() -> NodeFeatures {
1751 let mut features = NodeFeatures::empty();
1752 features.set_variable_length_onion_optional();
1756 struct LoggedPayeePubkey(Option<PublicKey>);
1757 impl fmt::Display for LoggedPayeePubkey {
1758 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1761 "payee node id ".fmt(f)?;
1765 "blinded payee".fmt(f)
1771 struct LoggedCandidateHop<'a>(&'a CandidateRouteHop<'a>);
1772 impl<'a> fmt::Display for LoggedCandidateHop<'a> {
1773 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1775 CandidateRouteHop::Blinded(BlindedPathCandidate { hint, .. }) | CandidateRouteHop::OneHopBlinded(OneHopBlindedPathCandidate { hint, .. }) => {
1776 "blinded route hint with introduction node ".fmt(f)?;
1777 match &hint.1.introduction_node {
1778 IntroductionNode::NodeId(pubkey) => write!(f, "id {}", pubkey)?,
1779 IntroductionNode::DirectedShortChannelId(direction, scid) => {
1781 Direction::NodeOne => {
1782 write!(f, "one on channel with SCID {}", scid)?;
1784 Direction::NodeTwo => {
1785 write!(f, "two on channel with SCID {}", scid)?;
1790 " and blinding point ".fmt(f)?;
1791 hint.1.blinding_point.fmt(f)
1793 CandidateRouteHop::FirstHop(_) => {
1794 "first hop with SCID ".fmt(f)?;
1795 self.0.short_channel_id().unwrap().fmt(f)
1797 CandidateRouteHop::PrivateHop(_) => {
1798 "route hint with SCID ".fmt(f)?;
1799 self.0.short_channel_id().unwrap().fmt(f)
1803 self.0.short_channel_id().unwrap().fmt(f)
1810 fn sort_first_hop_channels(
1811 channels: &mut Vec<&ChannelDetails>, used_liquidities: &HashMap<CandidateHopId, u64>,
1812 recommended_value_msat: u64, our_node_pubkey: &PublicKey
1814 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1815 // most like to use.
1817 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1818 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1821 // Second, because simply always sorting in descending order would always use our largest
1822 // available outbound capacity, needlessly fragmenting our available channel capacities,
1823 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1824 // which have enough, but not too much, capacity for the payment.
1826 // Available outbound balances factor in liquidity already reserved for previously found paths.
1827 channels.sort_unstable_by(|chan_a, chan_b| {
1828 let chan_a_outbound_limit_msat = chan_a.next_outbound_htlc_limit_msat
1829 .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_a.get_outbound_payment_scid().unwrap(),
1830 our_node_pubkey < &chan_a.counterparty.node_id))).unwrap_or(&0));
1831 let chan_b_outbound_limit_msat = chan_b.next_outbound_htlc_limit_msat
1832 .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_b.get_outbound_payment_scid().unwrap(),
1833 our_node_pubkey < &chan_b.counterparty.node_id))).unwrap_or(&0));
1834 if chan_b_outbound_limit_msat < recommended_value_msat || chan_a_outbound_limit_msat < recommended_value_msat {
1835 // Sort in descending order
1836 chan_b_outbound_limit_msat.cmp(&chan_a_outbound_limit_msat)
1838 // Sort in ascending order
1839 chan_a_outbound_limit_msat.cmp(&chan_b_outbound_limit_msat)
1844 /// Finds a route from us (payer) to the given target node (payee).
1846 /// If the payee provided features in their invoice, they should be provided via the `payee` field
1847 /// in the given [`RouteParameters::payment_params`].
1848 /// Without this, MPP will only be used if the payee's features are available in the network graph.
1850 /// Private routing paths between a public node and the target may be included in the `payee` field
1851 /// of [`RouteParameters::payment_params`].
1853 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
1854 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
1855 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
1857 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1858 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1859 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1863 /// Panics if first_hops contains channels without `short_channel_id`s;
1864 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1866 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1867 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1868 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1869 pub fn find_route<L: Deref, GL: Deref, S: ScoreLookUp>(
1870 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1871 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1872 scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
1873 ) -> Result<Route, LightningError>
1874 where L::Target: Logger, GL::Target: Logger {
1875 let graph_lock = network_graph.read_only();
1876 let mut route = get_route(our_node_pubkey, &route_params, &graph_lock, first_hops, logger,
1877 scorer, score_params, random_seed_bytes)?;
1878 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1882 pub(crate) fn get_route<L: Deref, S: ScoreLookUp>(
1883 our_node_pubkey: &PublicKey, route_params: &RouteParameters, network_graph: &ReadOnlyNetworkGraph,
1884 first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S, score_params: &S::ScoreParams,
1885 _random_seed_bytes: &[u8; 32]
1886 ) -> Result<Route, LightningError>
1887 where L::Target: Logger {
1889 let payment_params = &route_params.payment_params;
1890 let max_path_length = core::cmp::min(payment_params.max_path_length, MAX_PATH_LENGTH_ESTIMATE);
1891 let final_value_msat = route_params.final_value_msat;
1892 // If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
1893 // unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
1894 // so use a dummy id for this in the blinded case.
1895 let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
1896 const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [2; 33];
1897 let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
1898 let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
1899 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1901 if payee_node_id_opt.map_or(false, |payee| payee == our_node_id) {
1902 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1904 if our_node_id == maybe_dummy_payee_node_id {
1905 return Err(LightningError{err: "Invalid origin node id provided, use a different one".to_owned(), action: ErrorAction::IgnoreError});
1908 if final_value_msat > MAX_VALUE_MSAT {
1909 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1912 if final_value_msat == 0 {
1913 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1916 let introduction_node_id_cache = payment_params.payee.blinded_route_hints().iter()
1917 .map(|(_, path)| path.public_introduction_node_id(network_graph))
1918 .collect::<Vec<_>>();
1919 match &payment_params.payee {
1920 Payee::Clear { route_hints, node_id, .. } => {
1921 for route in route_hints.iter() {
1922 for hop in &route.0 {
1923 if hop.src_node_id == *node_id {
1924 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1929 Payee::Blinded { route_hints, .. } => {
1930 if introduction_node_id_cache.iter().all(|introduction_node_id| *introduction_node_id == Some(&our_node_id)) {
1931 return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
1933 for ((_, blinded_path), introduction_node_id) in route_hints.iter().zip(introduction_node_id_cache.iter()) {
1934 if blinded_path.blinded_hops.len() == 0 {
1935 return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
1936 } else if *introduction_node_id == Some(&our_node_id) {
1937 log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
1938 } else if blinded_path.blinded_hops.len() == 1 &&
1940 .iter().zip(introduction_node_id_cache.iter())
1941 .filter(|((_, p), _)| p.blinded_hops.len() == 1)
1942 .any(|(_, p_introduction_node_id)| p_introduction_node_id != introduction_node_id)
1944 return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
1949 let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
1950 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1951 return Err(LightningError{err: "Can't find a route where the maximum total CLTV expiry delta is below the final CLTV expiry.".to_owned(), action: ErrorAction::IgnoreError});
1954 // The general routing idea is the following:
1955 // 1. Fill first/last hops communicated by the caller.
1956 // 2. Attempt to construct a path from payer to payee for transferring
1957 // any ~sufficient (described later) value.
1958 // If succeed, remember which channels were used and how much liquidity they have available,
1959 // so that future paths don't rely on the same liquidity.
1960 // 3. Proceed to the next step if:
1961 // - we hit the recommended target value;
1962 // - OR if we could not construct a new path. Any next attempt will fail too.
1963 // Otherwise, repeat step 2.
1964 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1965 // (not recommended value).
1966 // 5. If yes, proceed. If not, fail routing.
1967 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1968 // transferred up to the transfer target value.
1969 // 7. Reduce the value of the last path until we are sending only the target value.
1970 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1971 // them so that we're not sending two HTLCs along the same path.
1973 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1974 // distance from the payee
1976 // We are not a faithful Dijkstra's implementation because we can change values which impact
1977 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1978 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1979 // the value we are currently attempting to send over a path, we simply reduce the value being
1980 // sent along the path for any hops after that channel. This may imply that later fees (which
1981 // we've already tabulated) are lower because a smaller value is passing through the channels
1982 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1983 // channels which were selected earlier (and which may still be used for other paths without a
1984 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1987 // One potentially problematic case for this algorithm would be if there are many
1988 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1989 // graph walking), we may never find a path which is not liquidity-limited and has lower
1990 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1991 // Because we only consider paths with at least 5% of the total value being sent, the damage
1992 // from such a case should be limited, however this could be further reduced in the future by
1993 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1994 // limits for the purposes of fee calculation.
1996 // Alternatively, we could store more detailed path information in the heap (targets, below)
1997 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1998 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1999 // and practically (as we would need to store dynamically-allocated path information in heap
2000 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
2001 // results of such an algorithm would likely be biased towards lower-value paths.
2003 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
2004 // outside of our current search value, running a path search more times to gather candidate
2005 // paths at different values. While this may be acceptable, further path searches may increase
2006 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
2007 // graph for candidate paths, calculating the maximum value which can realistically be sent at
2008 // the same time, remaining generic across different payment values.
2010 let network_channels = network_graph.channels();
2011 let network_nodes = network_graph.nodes();
2013 if payment_params.max_path_count == 0 {
2014 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
2017 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
2018 // it. If the payee supports it they're supposed to include it in the invoice, so that should
2020 let allow_mpp = if payment_params.max_path_count == 1 {
2022 } else if payment_params.payee.supports_basic_mpp() {
2024 } else if let Some(payee) = payee_node_id_opt {
2025 network_nodes.get(&payee).map_or(false, |node| node.announcement_info.as_ref().map_or(false,
2026 |info| info.features().supports_basic_mpp()))
2029 let max_total_routing_fee_msat = route_params.max_total_routing_fee_msat.unwrap_or(u64::max_value());
2031 let first_hop_count = first_hops.map(|hops| hops.len()).unwrap_or(0);
2032 log_trace!(logger, "Searching for a route from payer {} to {} {} MPP and {} first hops {}overriding the network graph of {} nodes and {} channels with a fee limit of {} msat",
2033 our_node_pubkey, LoggedPayeePubkey(payment_params.payee.node_id()),
2034 if allow_mpp { "with" } else { "without" },
2035 first_hop_count, if first_hops.is_some() { "" } else { "not " },
2036 network_graph.nodes().len(), network_graph.channels().len(),
2037 max_total_routing_fee_msat);
2039 if first_hop_count < 10 {
2040 if let Some(hops) = first_hops {
2044 " First hop through {}/{} can send between {}msat and {}msat (inclusive).",
2045 hop.counterparty.node_id,
2046 hop.get_outbound_payment_scid().unwrap_or(0),
2047 hop.next_outbound_htlc_minimum_msat,
2048 hop.next_outbound_htlc_limit_msat
2055 // Prepare the data we'll use for payee-to-payer search by
2056 // inserting first hops suggested by the caller as targets.
2057 // Our search will then attempt to reach them while traversing from the payee node.
2058 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
2059 hash_map_with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
2060 if let Some(hops) = first_hops {
2062 if chan.get_outbound_payment_scid().is_none() {
2063 panic!("first_hops should be filled in with usable channels, not pending ones");
2065 if chan.counterparty.node_id == *our_node_pubkey {
2066 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
2069 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
2070 .or_insert(Vec::new())
2073 if first_hop_targets.is_empty() {
2074 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
2078 let mut private_hop_key_cache = hash_map_with_capacity(
2079 payment_params.payee.unblinded_route_hints().iter().map(|path| path.0.len()).sum()
2082 // Because we store references to private hop node_ids in `dist`, below, we need them to exist
2083 // (as `NodeId`, not `PublicKey`) for the lifetime of `dist`. Thus, we calculate all the keys
2084 // we'll need here and simply fetch them when routing.
2085 private_hop_key_cache.insert(maybe_dummy_payee_pk, NodeId::from_pubkey(&maybe_dummy_payee_pk));
2086 for route in payment_params.payee.unblinded_route_hints().iter() {
2087 for hop in route.0.iter() {
2088 private_hop_key_cache.insert(hop.src_node_id, NodeId::from_pubkey(&hop.src_node_id));
2092 // The main heap containing all candidate next-hops sorted by their score (max(fee,
2093 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
2094 // adding duplicate entries when we find a better path to a given node.
2095 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
2097 // Map from node_id to information about the best current path to that node, including feerate
2099 let mut dist: HashMap<NodeId, PathBuildingHop> = hash_map_with_capacity(network_nodes.len());
2101 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
2102 // indicating that we may wish to try again with a higher value, potentially paying to meet an
2103 // htlc_minimum with extra fees while still finding a cheaper path.
2104 let mut hit_minimum_limit;
2106 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
2107 // We start with a path_value of the exact amount we want, and if that generates a route we may
2108 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
2109 // amount we want in total across paths, selecting the best subset at the end.
2110 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
2111 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
2112 let mut path_value_msat = final_value_msat;
2114 // Routing Fragmentation Mitigation heuristic:
2116 // Routing fragmentation across many payment paths increases the overall routing
2117 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
2118 // Taking too many smaller paths also increases the chance of payment failure.
2119 // Thus to avoid this effect, we require from our collected links to provide
2120 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
2121 // This requirement is currently set to be 1/max_path_count of the payment
2122 // value to ensure we only ever return routes that do not violate this limit.
2123 let minimal_value_contribution_msat: u64 = if allow_mpp {
2124 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
2129 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
2130 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
2131 // drop the requirement by setting this to 0.
2132 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
2134 // Keep track of how much liquidity has been used in selected channels or blinded paths. Used to
2135 // determine if the channel can be used by additional MPP paths or to inform path finding
2136 // decisions. It is aware of direction *only* to ensure that the correct htlc_maximum_msat value
2137 // is used. Hence, liquidity used in one direction will not offset any used in the opposite
2139 let mut used_liquidities: HashMap<CandidateHopId, u64> =
2140 hash_map_with_capacity(network_nodes.len());
2142 // Keeping track of how much value we already collected across other paths. Helps to decide
2143 // when we want to stop looking for new paths.
2144 let mut already_collected_value_msat = 0;
2146 for (_, channels) in first_hop_targets.iter_mut() {
2147 sort_first_hop_channels(channels, &used_liquidities, recommended_value_msat,
2151 log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
2152 LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
2154 // Remember how many candidates we ignored to allow for some logging afterwards.
2155 let mut num_ignored_value_contribution: u32 = 0;
2156 let mut num_ignored_path_length_limit: u32 = 0;
2157 let mut num_ignored_cltv_delta_limit: u32 = 0;
2158 let mut num_ignored_previously_failed: u32 = 0;
2159 let mut num_ignored_total_fee_limit: u32 = 0;
2160 let mut num_ignored_avoid_overpayment: u32 = 0;
2161 let mut num_ignored_htlc_minimum_msat_limit: u32 = 0;
2163 macro_rules! add_entry {
2164 // Adds entry which goes from $candidate.source() to $candidate.target() over the $candidate hop.
2165 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
2166 // since that value has to be transferred over this channel.
2167 // Returns the contribution amount of $candidate if the channel caused an update to `targets`.
2168 ( $candidate: expr, $next_hops_fee_msat: expr,
2169 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
2170 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
2171 // We "return" whether we updated the path at the end, and how much we can route via
2172 // this channel, via this:
2173 let mut hop_contribution_amt_msat = None;
2174 // Channels to self should not be used. This is more of belt-and-suspenders, because in
2175 // practice these cases should be caught earlier:
2176 // - for regular channels at channel announcement (TODO)
2177 // - for first and last hops early in get_route
2178 let src_node_id = $candidate.source();
2179 if Some(src_node_id) != $candidate.target() {
2180 let scid_opt = $candidate.short_channel_id();
2181 let effective_capacity = $candidate.effective_capacity();
2182 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
2184 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
2185 // It may be misleading because we might later choose to reduce the value transferred
2186 // over these channels, and the channel which was insufficient might become sufficient.
2187 // Worst case: we drop a good channel here because it can't cover the high following
2188 // fees caused by one expensive channel, but then this channel could have been used
2189 // if the amount being transferred over this path is lower.
2190 // We do this for now, but this is a subject for removal.
2191 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
2192 let used_liquidity_msat = used_liquidities
2193 .get(&$candidate.id())
2194 .map_or(0, |used_liquidity_msat| {
2195 available_value_contribution_msat = available_value_contribution_msat
2196 .saturating_sub(*used_liquidity_msat);
2197 *used_liquidity_msat
2200 // Verify the liquidity offered by this channel complies to the minimal contribution.
2201 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
2202 // Do not consider candidate hops that would exceed the maximum path length.
2203 let path_length_to_node = $next_hops_path_length
2204 + if $candidate.blinded_hint_idx().is_some() { 0 } else { 1 };
2205 let exceeds_max_path_length = path_length_to_node > max_path_length;
2207 // Do not consider candidates that exceed the maximum total cltv expiry limit.
2208 // In order to already account for some of the privacy enhancing random CLTV
2209 // expiry delta offset we add on top later, we subtract a rough estimate
2210 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
2211 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
2212 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
2213 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
2214 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
2215 .saturating_add($candidate.cltv_expiry_delta());
2216 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
2218 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
2219 // Includes paying fees for the use of the following channels.
2220 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
2221 Some(result) => result,
2222 // Can't overflow due to how the values were computed right above.
2223 None => unreachable!(),
2225 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
2226 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
2227 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
2229 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
2230 let may_overpay_to_meet_path_minimum_msat =
2231 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
2232 recommended_value_msat >= $candidate.htlc_minimum_msat()) ||
2233 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
2234 recommended_value_msat >= $next_hops_path_htlc_minimum_msat));
2236 let payment_failed_on_this_channel = match scid_opt {
2237 Some(scid) => payment_params.previously_failed_channels.contains(&scid),
2238 None => match $candidate.blinded_hint_idx() {
2240 payment_params.previously_failed_blinded_path_idxs.contains(&(idx as u64))
2246 let (should_log_candidate, first_hop_details) = match $candidate {
2247 CandidateRouteHop::FirstHop(hop) => (true, Some(hop.details)),
2248 CandidateRouteHop::PrivateHop(_) => (true, None),
2249 CandidateRouteHop::Blinded(_) => (true, None),
2250 CandidateRouteHop::OneHopBlinded(_) => (true, None),
2254 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
2255 // bother considering this channel. If retrying with recommended_value_msat may
2256 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
2257 // around again with a higher amount.
2258 if !contributes_sufficient_value {
2259 if should_log_candidate {
2260 log_trace!(logger, "Ignoring {} due to insufficient value contribution (channel max {:?}).",
2261 LoggedCandidateHop(&$candidate),
2262 effective_capacity);
2264 num_ignored_value_contribution += 1;
2265 } else if exceeds_max_path_length {
2266 if should_log_candidate {
2267 log_trace!(logger, "Ignoring {} due to exceeding maximum path length limit.", LoggedCandidateHop(&$candidate));
2269 num_ignored_path_length_limit += 1;
2270 } else if exceeds_cltv_delta_limit {
2271 if should_log_candidate {
2272 log_trace!(logger, "Ignoring {} due to exceeding CLTV delta limit.", LoggedCandidateHop(&$candidate));
2274 if let Some(_) = first_hop_details {
2276 "First hop candidate cltv_expiry_delta: {}. Limit: {}",
2277 hop_total_cltv_delta,
2278 max_total_cltv_expiry_delta,
2282 num_ignored_cltv_delta_limit += 1;
2283 } else if payment_failed_on_this_channel {
2284 if should_log_candidate {
2285 log_trace!(logger, "Ignoring {} due to a failed previous payment attempt.", LoggedCandidateHop(&$candidate));
2287 num_ignored_previously_failed += 1;
2288 } else if may_overpay_to_meet_path_minimum_msat {
2289 if should_log_candidate {
2291 "Ignoring {} to avoid overpaying to meet htlc_minimum_msat limit ({}).",
2292 LoggedCandidateHop(&$candidate), $candidate.htlc_minimum_msat());
2294 num_ignored_avoid_overpayment += 1;
2295 hit_minimum_limit = true;
2296 } else if over_path_minimum_msat {
2297 // Note that low contribution here (limited by available_liquidity_msat)
2298 // might violate htlc_minimum_msat on the hops which are next along the
2299 // payment path (upstream to the payee). To avoid that, we recompute
2300 // path fees knowing the final path contribution after constructing it.
2301 let curr_min = cmp::max(
2302 $next_hops_path_htlc_minimum_msat, $candidate.htlc_minimum_msat()
2304 let path_htlc_minimum_msat = compute_fees_saturating(curr_min, $candidate.fees())
2305 .saturating_add(curr_min);
2306 let hm_entry = dist.entry(src_node_id);
2307 let old_entry = hm_entry.or_insert_with(|| {
2308 // If there was previously no known way to access the source node
2309 // (recall it goes payee-to-payer) of short_channel_id, first add a
2310 // semi-dummy record just to compute the fees to reach the source node.
2311 // This will affect our decision on selecting short_channel_id
2312 // as a way to reach the $candidate.target() node.
2314 candidate: $candidate.clone(),
2316 next_hops_fee_msat: u64::max_value(),
2317 hop_use_fee_msat: u64::max_value(),
2318 total_fee_msat: u64::max_value(),
2319 path_htlc_minimum_msat,
2320 path_penalty_msat: u64::max_value(),
2321 was_processed: false,
2322 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
2323 value_contribution_msat,
2327 #[allow(unused_mut)] // We only use the mut in cfg(test)
2328 let mut should_process = !old_entry.was_processed;
2329 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
2331 // In test/fuzzing builds, we do extra checks to make sure the skipping
2332 // of already-seen nodes only happens in cases we expect (see below).
2333 if !should_process { should_process = true; }
2337 let mut hop_use_fee_msat = 0;
2338 let mut total_fee_msat: u64 = $next_hops_fee_msat;
2340 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
2341 // will have the same effective-fee
2342 if src_node_id != our_node_id {
2343 // Note that `u64::max_value` means we'll always fail the
2344 // `old_entry.total_fee_msat > total_fee_msat` check below
2345 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
2346 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
2349 // Ignore hops if augmenting the current path to them would put us over `max_total_routing_fee_msat`
2350 if total_fee_msat > max_total_routing_fee_msat {
2351 if should_log_candidate {
2352 log_trace!(logger, "Ignoring {} due to exceeding max total routing fee limit.", LoggedCandidateHop(&$candidate));
2354 if let Some(_) = first_hop_details {
2356 "First hop candidate routing fee: {}. Limit: {}",
2358 max_total_routing_fee_msat,
2362 num_ignored_total_fee_limit += 1;
2364 let channel_usage = ChannelUsage {
2365 amount_msat: amount_to_transfer_over_msat,
2366 inflight_htlc_msat: used_liquidity_msat,
2369 let channel_penalty_msat =
2370 scorer.channel_penalty_msat($candidate,
2373 let path_penalty_msat = $next_hops_path_penalty_msat
2374 .saturating_add(channel_penalty_msat);
2376 // Update the way of reaching $candidate.source()
2377 // with the given short_channel_id (from $candidate.target()),
2378 // if this way is cheaper than the already known
2379 // (considering the cost to "reach" this channel from the route destination,
2380 // the cost of using this channel,
2381 // and the cost of routing to the source node of this channel).
2382 // Also, consider that htlc_minimum_msat_difference, because we might end up
2383 // paying it. Consider the following exploit:
2384 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
2385 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
2386 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
2387 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
2389 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
2390 // but it may require additional tracking - we don't want to double-count
2391 // the fees included in $next_hops_path_htlc_minimum_msat, but also
2392 // can't use something that may decrease on future hops.
2393 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
2394 .saturating_add(old_entry.path_penalty_msat);
2395 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
2396 .saturating_add(path_penalty_msat);
2398 if !old_entry.was_processed && new_cost < old_cost {
2399 let new_graph_node = RouteGraphNode {
2400 node_id: src_node_id,
2401 score: cmp::max(total_fee_msat, path_htlc_minimum_msat).saturating_add(path_penalty_msat),
2402 total_cltv_delta: hop_total_cltv_delta,
2403 value_contribution_msat,
2404 path_length_to_node,
2406 targets.push(new_graph_node);
2407 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
2408 old_entry.hop_use_fee_msat = hop_use_fee_msat;
2409 old_entry.total_fee_msat = total_fee_msat;
2410 old_entry.candidate = $candidate.clone();
2411 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
2412 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
2413 old_entry.path_penalty_msat = path_penalty_msat;
2414 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
2416 old_entry.value_contribution_msat = value_contribution_msat;
2418 hop_contribution_amt_msat = Some(value_contribution_msat);
2419 } else if old_entry.was_processed && new_cost < old_cost {
2420 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
2422 // If we're skipping processing a node which was previously
2423 // processed even though we found another path to it with a
2424 // cheaper fee, check that it was because the second path we
2425 // found (which we are processing now) has a lower value
2426 // contribution due to an HTLC minimum limit.
2428 // e.g. take a graph with two paths from node 1 to node 2, one
2429 // through channel A, and one through channel B. Channel A and
2430 // B are both in the to-process heap, with their scores set by
2431 // a higher htlc_minimum than fee.
2432 // Channel A is processed first, and the channels onwards from
2433 // node 1 are added to the to-process heap. Thereafter, we pop
2434 // Channel B off of the heap, note that it has a much more
2435 // restrictive htlc_maximum_msat, and recalculate the fees for
2436 // all of node 1's channels using the new, reduced, amount.
2438 // This would be bogus - we'd be selecting a higher-fee path
2439 // with a lower htlc_maximum_msat instead of the one we'd
2440 // already decided to use.
2441 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
2443 value_contribution_msat + path_penalty_msat <
2444 old_entry.value_contribution_msat + old_entry.path_penalty_msat
2451 if should_log_candidate {
2453 "Ignoring {} due to its htlc_minimum_msat limit.",
2454 LoggedCandidateHop(&$candidate));
2456 if let Some(details) = first_hop_details {
2458 "First hop candidate next_outbound_htlc_minimum_msat: {}",
2459 details.next_outbound_htlc_minimum_msat,
2463 num_ignored_htlc_minimum_msat_limit += 1;
2467 hop_contribution_amt_msat
2471 let default_node_features = default_node_features();
2473 // Find ways (channels with destination) to reach a given node and store them
2474 // in the corresponding data structures (routing graph etc).
2475 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
2476 // meaning how much will be paid in fees after this node (to the best of our knowledge).
2477 // This data can later be helpful to optimize routing (pay lower fees).
2478 macro_rules! add_entries_to_cheapest_to_target_node {
2479 ( $node: expr, $node_id: expr, $next_hops_value_contribution: expr,
2480 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
2481 let fee_to_target_msat;
2482 let next_hops_path_htlc_minimum_msat;
2483 let next_hops_path_penalty_msat;
2484 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
2485 let was_processed = elem.was_processed;
2486 elem.was_processed = true;
2487 fee_to_target_msat = elem.total_fee_msat;
2488 next_hops_path_htlc_minimum_msat = elem.path_htlc_minimum_msat;
2489 next_hops_path_penalty_msat = elem.path_penalty_msat;
2492 // Entries are added to dist in add_entry!() when there is a channel from a node.
2493 // Because there are no channels from payee, it will not have a dist entry at this point.
2494 // If we're processing any other node, it is always be the result of a channel from it.
2495 debug_assert_eq!($node_id, maybe_dummy_payee_node_id);
2496 fee_to_target_msat = 0;
2497 next_hops_path_htlc_minimum_msat = 0;
2498 next_hops_path_penalty_msat = 0;
2503 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
2504 for details in first_channels {
2505 let candidate = CandidateRouteHop::FirstHop(FirstHopCandidate {
2506 details, payer_node_id: &our_node_id,
2508 add_entry!(&candidate, fee_to_target_msat,
2509 $next_hops_value_contribution,
2510 next_hops_path_htlc_minimum_msat, next_hops_path_penalty_msat,
2511 $next_hops_cltv_delta, $next_hops_path_length);
2515 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
2516 &node_info.features()
2518 &default_node_features
2521 if !features.requires_unknown_bits() {
2522 for chan_id in $node.channels.iter() {
2523 let chan = network_channels.get(chan_id).unwrap();
2524 if !chan.features.requires_unknown_bits() {
2525 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
2526 if first_hops.is_none() || *source != our_node_id {
2527 if directed_channel.direction().enabled {
2528 let candidate = CandidateRouteHop::PublicHop(PublicHopCandidate {
2529 info: directed_channel,
2530 short_channel_id: *chan_id,
2532 add_entry!(&candidate,
2534 $next_hops_value_contribution,
2535 next_hops_path_htlc_minimum_msat,
2536 next_hops_path_penalty_msat,
2537 $next_hops_cltv_delta, $next_hops_path_length);
2548 let mut payment_paths = Vec::<PaymentPath>::new();
2550 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
2551 'paths_collection: loop {
2552 // For every new path, start from scratch, except for used_liquidities, which
2553 // helps to avoid reusing previously selected paths in future iterations.
2556 hit_minimum_limit = false;
2558 // If first hop is a private channel and the only way to reach the payee, this is the only
2559 // place where it could be added.
2560 payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| {
2561 for details in first_channels {
2562 let candidate = CandidateRouteHop::FirstHop(FirstHopCandidate {
2563 details, payer_node_id: &our_node_id,
2565 let added = add_entry!(&candidate, 0, path_value_msat,
2566 0, 0u64, 0, 0).is_some();
2567 log_trace!(logger, "{} direct route to payee via {}",
2568 if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate));
2572 // Add the payee as a target, so that the payee-to-payer
2573 // search algorithm knows what to start with.
2574 payee_node_id_opt.map(|payee| match network_nodes.get(&payee) {
2575 // The payee is not in our network graph, so nothing to add here.
2576 // There is still a chance of reaching them via last_hops though,
2577 // so don't yet fail the payment here.
2578 // If not, targets.pop() will not even let us enter the loop in step 2.
2581 add_entries_to_cheapest_to_target_node!(node, payee, path_value_msat, 0, 0);
2586 // If a caller provided us with last hops, add them to routing targets. Since this happens
2587 // earlier than general path finding, they will be somewhat prioritized, although currently
2588 // it matters only if the fees are exactly the same.
2589 for (hint_idx, hint) in payment_params.payee.blinded_route_hints().iter().enumerate() {
2590 // Only add the hops in this route to our candidate set if either
2591 // we have a direct channel to the first hop or the first hop is
2592 // in the regular network graph.
2593 let source_node_id = match introduction_node_id_cache[hint_idx] {
2594 Some(node_id) => node_id,
2595 None => match &hint.1.introduction_node {
2596 IntroductionNode::NodeId(pubkey) => {
2597 let node_id = NodeId::from_pubkey(&pubkey);
2598 match first_hop_targets.get_key_value(&node_id).map(|(key, _)| key) {
2599 Some(node_id) => node_id,
2603 IntroductionNode::DirectedShortChannelId(direction, scid) => {
2604 let first_hop = first_hop_targets.iter().find(|(_, channels)|
2607 .any(|details| Some(*scid) == details.get_outbound_payment_scid())
2610 Some((counterparty_node_id, _)) => {
2611 direction.select_node_id(&our_node_id, counterparty_node_id)
2618 if our_node_id == *source_node_id { continue }
2619 let candidate = if hint.1.blinded_hops.len() == 1 {
2620 CandidateRouteHop::OneHopBlinded(
2621 OneHopBlindedPathCandidate { source_node_id, hint, hint_idx }
2624 CandidateRouteHop::Blinded(BlindedPathCandidate { source_node_id, hint, hint_idx })
2626 let mut path_contribution_msat = path_value_msat;
2627 if let Some(hop_used_msat) = add_entry!(&candidate,
2628 0, path_contribution_msat, 0, 0_u64, 0, 0)
2630 path_contribution_msat = hop_used_msat;
2632 if let Some(first_channels) = first_hop_targets.get(source_node_id) {
2633 let mut first_channels = first_channels.clone();
2634 sort_first_hop_channels(
2635 &mut first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey
2637 for details in first_channels {
2638 let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate {
2639 details, payer_node_id: &our_node_id,
2641 let blinded_path_fee = match compute_fees(path_contribution_msat, candidate.fees()) {
2645 let path_min = candidate.htlc_minimum_msat().saturating_add(
2646 compute_fees_saturating(candidate.htlc_minimum_msat(), candidate.fees()));
2647 add_entry!(&first_hop_candidate, blinded_path_fee, path_contribution_msat, path_min,
2648 0_u64, candidate.cltv_expiry_delta(), 0);
2652 for route in payment_params.payee.unblinded_route_hints().iter()
2653 .filter(|route| !route.0.is_empty())
2655 let first_hop_src_id = NodeId::from_pubkey(&route.0.first().unwrap().src_node_id);
2656 let first_hop_src_is_reachable =
2657 // Only add the hops in this route to our candidate set if either we are part of
2658 // the first hop, we have a direct channel to the first hop, or the first hop is in
2659 // the regular network graph.
2660 our_node_id == first_hop_src_id ||
2661 first_hop_targets.get(&first_hop_src_id).is_some() ||
2662 network_nodes.get(&first_hop_src_id).is_some();
2663 if first_hop_src_is_reachable {
2664 // We start building the path from reverse, i.e., from payee
2665 // to the first RouteHintHop in the path.
2666 let hop_iter = route.0.iter().rev();
2667 let prev_hop_iter = core::iter::once(&maybe_dummy_payee_pk).chain(
2668 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
2669 let mut hop_used = true;
2670 let mut aggregate_next_hops_fee_msat: u64 = 0;
2671 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
2672 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
2673 let mut aggregate_next_hops_cltv_delta: u32 = 0;
2674 let mut aggregate_next_hops_path_length: u8 = 0;
2675 let mut aggregate_path_contribution_msat = path_value_msat;
2677 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
2678 let target = private_hop_key_cache.get(prev_hop_id).unwrap();
2680 if let Some(first_channels) = first_hop_targets.get(target) {
2681 if first_channels.iter().any(|d| d.outbound_scid_alias == Some(hop.short_channel_id)) {
2682 log_trace!(logger, "Ignoring route hint with SCID {} (and any previous) due to it being a direct channel of ours.",
2683 hop.short_channel_id);
2688 let candidate = network_channels
2689 .get(&hop.short_channel_id)
2690 .and_then(|channel| channel.as_directed_to(target))
2691 .map(|(info, _)| CandidateRouteHop::PublicHop(PublicHopCandidate {
2693 short_channel_id: hop.short_channel_id,
2695 .unwrap_or_else(|| CandidateRouteHop::PrivateHop(PrivateHopCandidate { hint: hop, target_node_id: target }));
2697 if let Some(hop_used_msat) = add_entry!(&candidate,
2698 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
2699 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
2700 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
2702 aggregate_path_contribution_msat = hop_used_msat;
2704 // If this hop was not used then there is no use checking the preceding
2705 // hops in the RouteHint. We can break by just searching for a direct
2706 // channel between last checked hop and first_hop_targets.
2710 let used_liquidity_msat = used_liquidities
2711 .get(&candidate.id()).copied()
2713 let channel_usage = ChannelUsage {
2714 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
2715 inflight_htlc_msat: used_liquidity_msat,
2716 effective_capacity: candidate.effective_capacity(),
2718 let channel_penalty_msat = scorer.channel_penalty_msat(
2719 &candidate, channel_usage, score_params
2721 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
2722 .saturating_add(channel_penalty_msat);
2724 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
2725 .saturating_add(hop.cltv_expiry_delta as u32);
2727 aggregate_next_hops_path_length = aggregate_next_hops_path_length
2730 // Searching for a direct channel between last checked hop and first_hop_targets
2731 if let Some(first_channels) = first_hop_targets.get(target) {
2732 let mut first_channels = first_channels.clone();
2733 sort_first_hop_channels(
2734 &mut first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey
2736 for details in first_channels {
2737 let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate {
2738 details, payer_node_id: &our_node_id,
2740 add_entry!(&first_hop_candidate,
2741 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
2742 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
2743 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
2751 // In the next values of the iterator, the aggregate fees already reflects
2752 // the sum of value sent from payer (final_value_msat) and routing fees
2753 // for the last node in the RouteHint. We need to just add the fees to
2754 // route through the current node so that the preceding node (next iteration)
2756 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
2757 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
2758 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
2760 // The next channel will need to relay this channel's min_htlc *plus* the fees taken by
2761 // this route hint's source node to forward said min over this channel.
2762 aggregate_next_hops_path_htlc_minimum_msat = {
2763 let curr_htlc_min = cmp::max(
2764 candidate.htlc_minimum_msat(), aggregate_next_hops_path_htlc_minimum_msat
2766 let curr_htlc_min_fee = if let Some(val) = compute_fees(curr_htlc_min, hop.fees) { val } else { break };
2767 if let Some(min) = curr_htlc_min.checked_add(curr_htlc_min_fee) { min } else { break }
2770 if idx == route.0.len() - 1 {
2771 // The last hop in this iterator is the first hop in
2772 // overall RouteHint.
2773 // If this hop connects to a node with which we have a direct channel,
2774 // ignore the network graph and, if the last hop was added, add our
2775 // direct channel to the candidate set.
2777 // Note that we *must* check if the last hop was added as `add_entry`
2778 // always assumes that the third argument is a node to which we have a
2780 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
2781 let mut first_channels = first_channels.clone();
2782 sort_first_hop_channels(
2783 &mut first_channels, &used_liquidities, recommended_value_msat, our_node_pubkey
2785 for details in first_channels {
2786 let first_hop_candidate = CandidateRouteHop::FirstHop(FirstHopCandidate {
2787 details, payer_node_id: &our_node_id,
2789 add_entry!(&first_hop_candidate,
2790 aggregate_next_hops_fee_msat,
2791 aggregate_path_contribution_msat,
2792 aggregate_next_hops_path_htlc_minimum_msat,
2793 aggregate_next_hops_path_penalty_msat,
2794 aggregate_next_hops_cltv_delta,
2795 aggregate_next_hops_path_length);
2803 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
2805 // At this point, targets are filled with the data from first and
2806 // last hops communicated by the caller, and the payment receiver.
2807 let mut found_new_path = false;
2810 // If this loop terminates due the exhaustion of targets, two situations are possible:
2811 // - not enough outgoing liquidity:
2812 // 0 < already_collected_value_msat < final_value_msat
2813 // - enough outgoing liquidity:
2814 // final_value_msat <= already_collected_value_msat < recommended_value_msat
2815 // Both these cases (and other cases except reaching recommended_value_msat) mean that
2816 // paths_collection will be stopped because found_new_path==false.
2817 // This is not necessarily a routing failure.
2818 'path_construction: while let Some(RouteGraphNode { node_id, total_cltv_delta, mut value_contribution_msat, path_length_to_node, .. }) = targets.pop() {
2820 // Since we're going payee-to-payer, hitting our node as a target means we should stop
2821 // traversing the graph and arrange the path out of what we found.
2822 if node_id == our_node_id {
2823 let mut new_entry = dist.remove(&our_node_id).unwrap();
2824 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
2827 let mut features_set = false;
2828 let target = ordered_hops.last().unwrap().0.candidate.target().unwrap_or(maybe_dummy_payee_node_id);
2829 if let Some(first_channels) = first_hop_targets.get(&target) {
2830 for details in first_channels {
2831 if let CandidateRouteHop::FirstHop(FirstHopCandidate { details: last_hop_details, .. })
2832 = ordered_hops.last().unwrap().0.candidate
2834 if details.get_outbound_payment_scid() == last_hop_details.get_outbound_payment_scid() {
2835 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
2836 features_set = true;
2843 if let Some(node) = network_nodes.get(&target) {
2844 if let Some(node_info) = node.announcement_info.as_ref() {
2845 ordered_hops.last_mut().unwrap().1 = node_info.features().clone();
2847 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
2850 // We can fill in features for everything except hops which were
2851 // provided via the invoice we're paying. We could guess based on the
2852 // recipient's features but for now we simply avoid guessing at all.
2856 // Means we successfully traversed from the payer to the payee, now
2857 // save this path for the payment route. Also, update the liquidity
2858 // remaining on the used hops, so that we take them into account
2859 // while looking for more paths.
2860 if target == maybe_dummy_payee_node_id {
2864 new_entry = match dist.remove(&target) {
2865 Some(payment_hop) => payment_hop,
2866 // We can't arrive at None because, if we ever add an entry to targets,
2867 // we also fill in the entry in dist (see add_entry!).
2868 None => unreachable!(),
2870 // We "propagate" the fees one hop backward (topologically) here,
2871 // so that fees paid for a HTLC forwarding on the current channel are
2872 // associated with the previous channel (where they will be subtracted).
2873 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
2874 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
2876 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
2877 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
2879 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
2880 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
2882 let mut payment_path = PaymentPath {hops: ordered_hops};
2884 // We could have possibly constructed a slightly inconsistent path: since we reduce
2885 // value being transferred along the way, we could have violated htlc_minimum_msat
2886 // on some channels we already passed (assuming dest->source direction). Here, we
2887 // recompute the fees again, so that if that's the case, we match the currently
2888 // underpaid htlc_minimum_msat with fees.
2889 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
2890 let desired_value_contribution = cmp::min(value_contribution_msat, final_value_msat);
2891 value_contribution_msat = payment_path.update_value_and_recompute_fees(desired_value_contribution);
2893 // Since a path allows to transfer as much value as
2894 // the smallest channel it has ("bottleneck"), we should recompute
2895 // the fees so sender HTLC don't overpay fees when traversing
2896 // larger channels than the bottleneck. This may happen because
2897 // when we were selecting those channels we were not aware how much value
2898 // this path will transfer, and the relative fee for them
2899 // might have been computed considering a larger value.
2900 // Remember that we used these channels so that we don't rely
2901 // on the same liquidity in future paths.
2902 let mut prevented_redundant_path_selection = false;
2903 for (hop, _) in payment_path.hops.iter() {
2904 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
2905 let used_liquidity_msat = used_liquidities
2906 .entry(hop.candidate.id())
2907 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
2908 .or_insert(spent_on_hop_msat);
2909 let hop_capacity = hop.candidate.effective_capacity();
2910 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
2911 if *used_liquidity_msat == hop_max_msat {
2912 // If this path used all of this channel's available liquidity, we know
2913 // this path will not be selected again in the next loop iteration.
2914 prevented_redundant_path_selection = true;
2916 debug_assert!(*used_liquidity_msat <= hop_max_msat);
2918 if !prevented_redundant_path_selection {
2919 // If we weren't capped by hitting a liquidity limit on a channel in the path,
2920 // we'll probably end up picking the same path again on the next iteration.
2921 // Decrease the available liquidity of a hop in the middle of the path.
2922 let victim_candidate = &payment_path.hops[(payment_path.hops.len()) / 2].0.candidate;
2923 let exhausted = u64::max_value();
2925 "Disabling route candidate {} for future path building iterations to avoid duplicates.",
2926 LoggedCandidateHop(victim_candidate));
2927 if let Some(scid) = victim_candidate.short_channel_id() {
2928 *used_liquidities.entry(CandidateHopId::Clear((scid, false))).or_default() = exhausted;
2929 *used_liquidities.entry(CandidateHopId::Clear((scid, true))).or_default() = exhausted;
2933 // Track the total amount all our collected paths allow to send so that we know
2934 // when to stop looking for more paths
2935 already_collected_value_msat += value_contribution_msat;
2937 payment_paths.push(payment_path);
2938 found_new_path = true;
2939 break 'path_construction;
2942 // If we found a path back to the payee, we shouldn't try to process it again. This is
2943 // the equivalent of the `elem.was_processed` check in
2944 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
2945 if node_id == maybe_dummy_payee_node_id { continue 'path_construction; }
2947 // Otherwise, since the current target node is not us,
2948 // keep "unrolling" the payment graph from payee to payer by
2949 // finding a way to reach the current target from the payer side.
2950 match network_nodes.get(&node_id) {
2953 add_entries_to_cheapest_to_target_node!(node, node_id,
2954 value_contribution_msat,
2955 total_cltv_delta, path_length_to_node);
2961 if !found_new_path && channel_saturation_pow_half != 0 {
2962 channel_saturation_pow_half = 0;
2963 continue 'paths_collection;
2965 // If we don't support MPP, no use trying to gather more value ever.
2966 break 'paths_collection;
2970 // Stop either when the recommended value is reached or if no new path was found in this
2972 // In the latter case, making another path finding attempt won't help,
2973 // because we deterministically terminated the search due to low liquidity.
2974 if !found_new_path && channel_saturation_pow_half != 0 {
2975 channel_saturation_pow_half = 0;
2976 } else if !found_new_path && hit_minimum_limit && already_collected_value_msat < final_value_msat && path_value_msat != recommended_value_msat {
2977 log_trace!(logger, "Failed to collect enough value, but running again to collect extra paths with a potentially higher limit.");
2978 path_value_msat = recommended_value_msat;
2979 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
2980 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
2981 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
2982 break 'paths_collection;
2983 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
2984 // Further, if this was our first walk of the graph, and we weren't limited by an
2985 // htlc_minimum_msat, return immediately because this path should suffice. If we were
2986 // limited by an htlc_minimum_msat value, find another path with a higher value,
2987 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
2988 // still keeping a lower total fee than this path.
2989 if !hit_minimum_limit {
2990 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
2991 break 'paths_collection;
2993 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher value to meet htlc_minimum_msat limit.");
2994 path_value_msat = recommended_value_msat;
2998 let num_ignored_total = num_ignored_value_contribution + num_ignored_path_length_limit +
2999 num_ignored_cltv_delta_limit + num_ignored_previously_failed +
3000 num_ignored_avoid_overpayment + num_ignored_htlc_minimum_msat_limit +
3001 num_ignored_total_fee_limit;
3002 if num_ignored_total > 0 {
3004 "Ignored {} candidate hops due to insufficient value contribution, {} due to path length limit, {} due to CLTV delta limit, {} due to previous payment failure, {} due to htlc_minimum_msat limit, {} to avoid overpaying, {} due to maximum total fee limit. Total: {} ignored candidates.",
3005 num_ignored_value_contribution, num_ignored_path_length_limit,
3006 num_ignored_cltv_delta_limit, num_ignored_previously_failed,
3007 num_ignored_htlc_minimum_msat_limit, num_ignored_avoid_overpayment,
3008 num_ignored_total_fee_limit, num_ignored_total);
3012 if payment_paths.len() == 0 {
3013 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
3016 if already_collected_value_msat < final_value_msat {
3017 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
3021 let mut selected_route = payment_paths;
3023 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
3024 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
3026 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
3027 // the value they contribute towards the payment amount.
3028 // We sort in descending order as we will remove from the front in `retain`, next.
3029 selected_route.sort_unstable_by(|a, b|
3030 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
3031 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
3034 // We should make sure that at least 1 path left.
3035 let mut paths_left = selected_route.len();
3036 selected_route.retain(|path| {
3037 if paths_left == 1 {
3040 let path_value_msat = path.get_value_msat();
3041 if path_value_msat <= overpaid_value_msat {
3042 overpaid_value_msat -= path_value_msat;
3048 debug_assert!(selected_route.len() > 0);
3050 if overpaid_value_msat != 0 {
3052 // Now, subtract the remaining overpaid value from the most-expensive path.
3053 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
3054 // so that the sender pays less fees overall. And also htlc_minimum_msat.
3055 selected_route.sort_unstable_by(|a, b| {
3056 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
3057 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
3058 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
3060 let expensive_payment_path = selected_route.first_mut().unwrap();
3062 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
3063 // can't go negative.
3064 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
3065 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
3069 // Sort by the path itself and combine redundant paths.
3070 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
3071 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
3073 selected_route.sort_unstable_by_key(|path| {
3074 let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize];
3075 debug_assert!(path.hops.len() <= key.len());
3076 for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id()).zip(key.iter_mut()) {
3081 for idx in 0..(selected_route.len() - 1) {
3082 if idx + 1 >= selected_route.len() { break; }
3083 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(), h.0.candidate.target())),
3084 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(), h.0.candidate.target()))) {
3085 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
3086 selected_route[idx].update_value_and_recompute_fees(new_value);
3087 selected_route.remove(idx + 1);
3091 let mut paths = Vec::new();
3092 for payment_path in selected_route {
3093 let mut hops = Vec::with_capacity(payment_path.hops.len());
3094 for (hop, node_features) in payment_path.hops.iter()
3095 .filter(|(h, _)| h.candidate.short_channel_id().is_some())
3097 let target = hop.candidate.target().expect("target is defined when short_channel_id is defined");
3098 let maybe_announced_channel = if let CandidateRouteHop::PublicHop(_) = hop.candidate {
3099 // If we sourced the hop from the graph we're sure the target node is announced.
3101 } else if let CandidateRouteHop::FirstHop(first_hop) = &hop.candidate {
3102 // If this is a first hop we also know if it's announced.
3103 first_hop.details.is_public
3105 // If we sourced it any other way, we double-check the network graph to see if
3106 // there are announced channels between the endpoints. If so, the hop might be
3107 // referring to any of the announced channels, as its `short_channel_id` might be
3108 // an alias, in which case we don't take any chances here.
3109 network_graph.node(&target).map_or(false, |hop_node|
3110 hop_node.channels.iter().any(|scid| network_graph.channel(*scid)
3111 .map_or(false, |c| c.as_directed_from(&hop.candidate.source()).is_some()))
3115 hops.push(RouteHop {
3116 pubkey: PublicKey::from_slice(target.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &target), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
3117 node_features: node_features.clone(),
3118 short_channel_id: hop.candidate.short_channel_id().unwrap(),
3119 channel_features: hop.candidate.features(),
3120 fee_msat: hop.fee_msat,
3121 cltv_expiry_delta: hop.candidate.cltv_expiry_delta(),
3122 maybe_announced_channel,
3125 let mut final_cltv_delta = final_cltv_expiry_delta;
3126 let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {
3127 if let Some(blinded_path) = h.candidate.blinded_path() {
3128 final_cltv_delta = h.candidate.cltv_expiry_delta();
3130 hops: blinded_path.blinded_hops.clone(),
3131 blinding_point: blinded_path.blinding_point,
3132 excess_final_cltv_expiry_delta: 0,
3133 final_value_msat: h.fee_msat,
3137 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
3138 // applicable for the previous hop.
3139 hops.iter_mut().rev().fold(final_cltv_delta, |prev_cltv_expiry_delta, hop| {
3140 core::mem::replace(&mut hop.cltv_expiry_delta, prev_cltv_expiry_delta)
3143 paths.push(Path { hops, blinded_tail });
3145 // Make sure we would never create a route with more paths than we allow.
3146 debug_assert!(paths.len() <= payment_params.max_path_count.into());
3148 if let Some(node_features) = payment_params.payee.node_features() {
3149 for path in paths.iter_mut() {
3150 path.hops.last_mut().unwrap().node_features = node_features.clone();
3154 let route = Route { paths, route_params: Some(route_params.clone()) };
3156 // Make sure we would never create a route whose total fees exceed max_total_routing_fee_msat.
3157 if let Some(max_total_routing_fee_msat) = route_params.max_total_routing_fee_msat {
3158 if route.get_total_fees() > max_total_routing_fee_msat {
3159 return Err(LightningError{err: format!("Failed to find route that adheres to the maximum total fee limit of {}msat",
3160 max_total_routing_fee_msat), action: ErrorAction::IgnoreError});
3164 log_info!(logger, "Got route: {}", log_route!(route));
3168 // When an adversarial intermediary node observes a payment, it may be able to infer its
3169 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
3170 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
3171 // payment path by adding a randomized 'shadow route' offset to the final hop.
3172 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
3173 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
3175 let network_channels = network_graph.channels();
3176 let network_nodes = network_graph.nodes();
3178 for path in route.paths.iter_mut() {
3179 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
3181 // Remember the last three nodes of the random walk and avoid looping back on them.
3182 // Init with the last three nodes from the actual path, if possible.
3183 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
3184 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(2)).unwrap().pubkey),
3185 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(3)).unwrap().pubkey)];
3187 // Choose the last publicly known node as the starting point for the random walk.
3188 let mut cur_hop: Option<NodeId> = None;
3189 let mut path_nonce = [0u8; 12];
3190 if let Some(starting_hop) = path.hops.iter().rev()
3191 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
3192 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
3193 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
3196 // Init PRNG with the path-dependant nonce, which is static for private paths.
3197 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
3198 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
3200 // Pick a random path length in [1 .. 3]
3201 prng.process_in_place(&mut random_path_bytes);
3202 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
3204 for random_hop in 0..random_walk_length {
3205 // If we don't find a suitable offset in the public network graph, we default to
3206 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
3207 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
3209 if let Some(cur_node_id) = cur_hop {
3210 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
3211 // Randomly choose the next unvisited hop.
3212 prng.process_in_place(&mut random_path_bytes);
3213 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
3214 .checked_rem(cur_node.channels.len())
3215 .and_then(|index| cur_node.channels.get(index))
3216 .and_then(|id| network_channels.get(id)) {
3217 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
3218 if !nodes_to_avoid.iter().any(|x| x == next_id) {
3219 nodes_to_avoid[random_hop] = *next_id;
3220 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
3221 cur_hop = Some(*next_id);
3228 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
3229 .checked_add(random_hop_offset)
3230 .unwrap_or(shadow_ctlv_expiry_delta_offset);
3233 // Limit the total offset to reduce the worst-case locked liquidity timevalue
3234 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
3235 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
3237 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
3238 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
3239 let path_total_cltv_expiry_delta: u32 = path.hops.iter().map(|h| h.cltv_expiry_delta).sum();
3240 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
3241 max_path_offset = cmp::max(
3242 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
3243 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
3244 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
3246 // Add 'shadow' CLTV offset to the final hop
3247 if let Some(tail) = path.blinded_tail.as_mut() {
3248 tail.excess_final_cltv_expiry_delta = tail.excess_final_cltv_expiry_delta
3249 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(tail.excess_final_cltv_expiry_delta);
3251 if let Some(last_hop) = path.hops.last_mut() {
3252 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
3253 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
3258 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
3259 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
3261 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
3262 pub fn build_route_from_hops<L: Deref, GL: Deref>(
3263 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
3264 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
3265 ) -> Result<Route, LightningError>
3266 where L::Target: Logger, GL::Target: Logger {
3267 let graph_lock = network_graph.read_only();
3268 let mut route = build_route_from_hops_internal(our_node_pubkey, hops, &route_params,
3269 &graph_lock, logger, random_seed_bytes)?;
3270 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
3274 fn build_route_from_hops_internal<L: Deref>(
3275 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
3276 network_graph: &ReadOnlyNetworkGraph, logger: L, random_seed_bytes: &[u8; 32],
3277 ) -> Result<Route, LightningError> where L::Target: Logger {
3280 our_node_id: NodeId,
3281 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
3284 impl ScoreLookUp for HopScorer {
3285 type ScoreParams = ();
3286 fn channel_penalty_msat(&self, candidate: &CandidateRouteHop,
3287 _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
3289 let mut cur_id = self.our_node_id;
3290 for i in 0..self.hop_ids.len() {
3291 if let Some(next_id) = self.hop_ids[i] {
3292 if cur_id == candidate.source() && Some(next_id) == candidate.target() {
3304 impl<'a> Writeable for HopScorer {
3306 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
3311 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
3312 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
3315 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
3316 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
3317 for i in 0..hops.len() {
3318 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
3321 let scorer = HopScorer { our_node_id, hop_ids };
3323 get_route(our_node_pubkey, route_params, network_graph, None, logger, &scorer, &Default::default(), random_seed_bytes)
3328 use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
3329 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
3330 use crate::routing::utxo::UtxoResult;
3331 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
3332 BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
3333 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE, RouteParameters, CandidateRouteHop, PublicHopCandidate};
3334 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, ScoreLookUp, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
3335 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
3336 use crate::chain::transaction::OutPoint;
3337 use crate::ln::channel_state::{ChannelCounterparty, ChannelDetails, ChannelShutdownState};
3338 use crate::ln::types::ChannelId;
3339 use crate::ln::features::{BlindedHopFeatures, ChannelFeatures, InitFeatures, NodeFeatures};
3340 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
3341 use crate::ln::channelmanager;
3342 use crate::offers::invoice::BlindedPayInfo;
3343 use crate::util::config::UserConfig;
3344 use crate::util::test_utils as ln_test_utils;
3345 use crate::crypto::chacha20::ChaCha20;
3346 use crate::util::ser::{Readable, Writeable};
3348 use crate::util::ser::Writer;
3350 use bitcoin::amount::Amount;
3351 use bitcoin::hashes::Hash;
3352 use bitcoin::network::Network;
3353 use bitcoin::blockdata::constants::ChainHash;
3354 use bitcoin::blockdata::script::Builder;
3355 use bitcoin::blockdata::opcodes;
3356 use bitcoin::blockdata::transaction::TxOut;
3357 use bitcoin::hashes::hex::FromHex;
3358 use bitcoin::secp256k1::{PublicKey,SecretKey};
3359 use bitcoin::secp256k1::Secp256k1;
3361 use crate::io::Cursor;
3362 use crate::prelude::*;
3363 use crate::sync::Arc;
3365 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
3366 features: InitFeatures, outbound_capacity_msat: u64) -> ChannelDetails {
3368 channel_id: ChannelId::new_zero(),
3369 counterparty: ChannelCounterparty {
3372 unspendable_punishment_reserve: 0,
3373 forwarding_info: None,
3374 outbound_htlc_minimum_msat: None,
3375 outbound_htlc_maximum_msat: None,
3377 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
3380 outbound_scid_alias: None,
3381 inbound_scid_alias: None,
3382 channel_value_satoshis: 0,
3385 outbound_capacity_msat,
3386 next_outbound_htlc_limit_msat: outbound_capacity_msat,
3387 next_outbound_htlc_minimum_msat: 0,
3388 inbound_capacity_msat: 42,
3389 unspendable_punishment_reserve: None,
3390 confirmations_required: None,
3391 confirmations: None,
3392 force_close_spend_delay: None,
3393 is_outbound: true, is_channel_ready: true,
3394 is_usable: true, is_public: true,
3395 inbound_htlc_minimum_msat: None,
3396 inbound_htlc_maximum_msat: None,
3398 feerate_sat_per_1000_weight: None,
3399 channel_shutdown_state: Some(ChannelShutdownState::NotShuttingDown),
3400 pending_inbound_htlcs: Vec::new(),
3401 pending_outbound_htlcs: Vec::new(),
3406 fn simple_route_test() {
3407 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3408 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3409 let mut payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3410 let scorer = ln_test_utils::TestScorer::new();
3411 let random_seed_bytes = [42; 32];
3413 // Simple route to 2 via 1
3415 let route_params = RouteParameters::from_payment_params_and_value(
3416 payment_params.clone(), 0);
3417 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3418 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
3419 &Default::default(), &random_seed_bytes) {
3420 assert_eq!(err, "Cannot send a payment of 0 msat");
3421 } else { panic!(); }
3423 payment_params.max_path_length = 2;
3424 let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3425 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3426 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3427 assert_eq!(route.paths[0].hops.len(), 2);
3429 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3430 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3431 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3432 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3433 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3434 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3436 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3437 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3438 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3439 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3440 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3441 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3443 route_params.payment_params.max_path_length = 1;
3444 get_route(&our_id, &route_params, &network_graph.read_only(), None,
3445 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap_err();
3449 fn invalid_first_hop_test() {
3450 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3451 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3452 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3453 let scorer = ln_test_utils::TestScorer::new();
3454 let random_seed_bytes = [42; 32];
3456 // Simple route to 2 via 1
3458 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
3460 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3461 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3462 &route_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()),
3463 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes) {
3464 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
3465 } else { panic!(); }
3467 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3468 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3469 assert_eq!(route.paths[0].hops.len(), 2);
3473 fn htlc_minimum_test() {
3474 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3475 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3476 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3477 let scorer = ln_test_utils::TestScorer::new();
3478 let random_seed_bytes = [42; 32];
3480 // Simple route to 2 via 1
3482 // Disable other paths
3483 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3484 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3485 short_channel_id: 12,
3487 flags: 2, // to disable
3488 cltv_expiry_delta: 0,
3489 htlc_minimum_msat: 0,
3490 htlc_maximum_msat: MAX_VALUE_MSAT,
3492 fee_proportional_millionths: 0,
3493 excess_data: Vec::new()
3495 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3496 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3497 short_channel_id: 3,
3499 flags: 2, // to disable
3500 cltv_expiry_delta: 0,
3501 htlc_minimum_msat: 0,
3502 htlc_maximum_msat: MAX_VALUE_MSAT,
3504 fee_proportional_millionths: 0,
3505 excess_data: Vec::new()
3507 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3508 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3509 short_channel_id: 13,
3511 flags: 2, // to disable
3512 cltv_expiry_delta: 0,
3513 htlc_minimum_msat: 0,
3514 htlc_maximum_msat: MAX_VALUE_MSAT,
3516 fee_proportional_millionths: 0,
3517 excess_data: Vec::new()
3519 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3520 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3521 short_channel_id: 6,
3523 flags: 2, // to disable
3524 cltv_expiry_delta: 0,
3525 htlc_minimum_msat: 0,
3526 htlc_maximum_msat: MAX_VALUE_MSAT,
3528 fee_proportional_millionths: 0,
3529 excess_data: Vec::new()
3531 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3532 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3533 short_channel_id: 7,
3535 flags: 2, // to disable
3536 cltv_expiry_delta: 0,
3537 htlc_minimum_msat: 0,
3538 htlc_maximum_msat: MAX_VALUE_MSAT,
3540 fee_proportional_millionths: 0,
3541 excess_data: Vec::new()
3544 // Check against amount_to_transfer_over_msat.
3545 // Set minimal HTLC of 200_000_000 msat.
3546 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3547 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3548 short_channel_id: 2,
3551 cltv_expiry_delta: 0,
3552 htlc_minimum_msat: 200_000_000,
3553 htlc_maximum_msat: MAX_VALUE_MSAT,
3555 fee_proportional_millionths: 0,
3556 excess_data: Vec::new()
3559 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
3561 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3562 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3563 short_channel_id: 4,
3566 cltv_expiry_delta: 0,
3567 htlc_minimum_msat: 0,
3568 htlc_maximum_msat: 199_999_999,
3570 fee_proportional_millionths: 0,
3571 excess_data: Vec::new()
3574 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
3575 let route_params = RouteParameters::from_payment_params_and_value(
3576 payment_params, 199_999_999);
3577 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3578 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
3579 &Default::default(), &random_seed_bytes) {
3580 assert_eq!(err, "Failed to find a path to the given destination");
3581 } else { panic!(); }
3583 // Lift the restriction on the first hop.
3584 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3585 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3586 short_channel_id: 2,
3589 cltv_expiry_delta: 0,
3590 htlc_minimum_msat: 0,
3591 htlc_maximum_msat: MAX_VALUE_MSAT,
3593 fee_proportional_millionths: 0,
3594 excess_data: Vec::new()
3597 // A payment above the minimum should pass
3598 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3599 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3600 assert_eq!(route.paths[0].hops.len(), 2);
3604 fn htlc_minimum_overpay_test() {
3605 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3606 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3607 let config = UserConfig::default();
3608 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
3609 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
3611 let scorer = ln_test_utils::TestScorer::new();
3612 let random_seed_bytes = [42; 32];
3614 // A route to node#2 via two paths.
3615 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
3616 // Thus, they can't send 60 without overpaying.
3617 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3618 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3619 short_channel_id: 2,
3622 cltv_expiry_delta: 0,
3623 htlc_minimum_msat: 35_000,
3624 htlc_maximum_msat: 40_000,
3626 fee_proportional_millionths: 0,
3627 excess_data: Vec::new()
3629 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3630 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3631 short_channel_id: 12,
3634 cltv_expiry_delta: 0,
3635 htlc_minimum_msat: 35_000,
3636 htlc_maximum_msat: 40_000,
3638 fee_proportional_millionths: 0,
3639 excess_data: Vec::new()
3643 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3644 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3645 short_channel_id: 13,
3648 cltv_expiry_delta: 0,
3649 htlc_minimum_msat: 0,
3650 htlc_maximum_msat: MAX_VALUE_MSAT,
3652 fee_proportional_millionths: 0,
3653 excess_data: Vec::new()
3655 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3656 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3657 short_channel_id: 4,
3660 cltv_expiry_delta: 0,
3661 htlc_minimum_msat: 0,
3662 htlc_maximum_msat: MAX_VALUE_MSAT,
3664 fee_proportional_millionths: 0,
3665 excess_data: Vec::new()
3668 // Disable other paths
3669 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3670 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3671 short_channel_id: 1,
3673 flags: 2, // to disable
3674 cltv_expiry_delta: 0,
3675 htlc_minimum_msat: 0,
3676 htlc_maximum_msat: MAX_VALUE_MSAT,
3678 fee_proportional_millionths: 0,
3679 excess_data: Vec::new()
3682 let mut route_params = RouteParameters::from_payment_params_and_value(
3683 payment_params.clone(), 60_000);
3684 route_params.max_total_routing_fee_msat = Some(15_000);
3685 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3686 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3687 // Overpay fees to hit htlc_minimum_msat.
3688 let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
3689 // TODO: this could be better balanced to overpay 10k and not 15k.
3690 assert_eq!(overpaid_fees, 15_000);
3692 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
3693 // while taking even more fee to match htlc_minimum_msat.
3694 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3695 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3696 short_channel_id: 12,
3699 cltv_expiry_delta: 0,
3700 htlc_minimum_msat: 65_000,
3701 htlc_maximum_msat: 80_000,
3703 fee_proportional_millionths: 0,
3704 excess_data: Vec::new()
3706 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3707 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3708 short_channel_id: 2,
3711 cltv_expiry_delta: 0,
3712 htlc_minimum_msat: 0,
3713 htlc_maximum_msat: MAX_VALUE_MSAT,
3715 fee_proportional_millionths: 0,
3716 excess_data: Vec::new()
3718 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3719 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3720 short_channel_id: 4,
3723 cltv_expiry_delta: 0,
3724 htlc_minimum_msat: 0,
3725 htlc_maximum_msat: MAX_VALUE_MSAT,
3727 fee_proportional_millionths: 100_000,
3728 excess_data: Vec::new()
3731 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3732 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3733 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
3734 assert_eq!(route.paths.len(), 1);
3735 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
3736 let fees = route.paths[0].hops[0].fee_msat;
3737 assert_eq!(fees, 5_000);
3739 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 50_000);
3740 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3741 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3742 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
3743 // the other channel.
3744 assert_eq!(route.paths.len(), 1);
3745 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3746 let fees = route.paths[0].hops[0].fee_msat;
3747 assert_eq!(fees, 5_000);
3751 fn htlc_minimum_recipient_overpay_test() {
3752 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3753 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3754 let config = UserConfig::default();
3755 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap();
3756 let scorer = ln_test_utils::TestScorer::new();
3757 let random_seed_bytes = [42; 32];
3759 // Route to node2 over a single path which requires overpaying the recipient themselves.
3761 // First disable all paths except the us -> node1 -> node2 path
3762 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3763 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3764 short_channel_id: 13,
3767 cltv_expiry_delta: 0,
3768 htlc_minimum_msat: 0,
3769 htlc_maximum_msat: 0,
3771 fee_proportional_millionths: 0,
3772 excess_data: Vec::new()
3775 // Set channel 4 to free but with a high htlc_minimum_msat
3776 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3777 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3778 short_channel_id: 4,
3781 cltv_expiry_delta: 0,
3782 htlc_minimum_msat: 15_000,
3783 htlc_maximum_msat: MAX_VALUE_MSAT,
3785 fee_proportional_millionths: 0,
3786 excess_data: Vec::new()
3789 // Now check that we'll fail to find a path if we fail to find a path if the htlc_minimum
3790 // is overrun. Note that the fees are actually calculated on 3*payment amount as that's
3791 // what we try to find a route for, so this test only just happens to work out to exactly
3793 let mut route_params = RouteParameters::from_payment_params_and_value(
3794 payment_params.clone(), 5_000);
3795 route_params.max_total_routing_fee_msat = Some(9_999);
3796 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3797 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
3798 &Default::default(), &random_seed_bytes) {
3799 assert_eq!(err, "Failed to find route that adheres to the maximum total fee limit of 9999msat");
3800 } else { panic!(); }
3802 let mut route_params = RouteParameters::from_payment_params_and_value(
3803 payment_params.clone(), 5_000);
3804 route_params.max_total_routing_fee_msat = Some(10_000);
3805 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3806 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3807 assert_eq!(route.get_total_fees(), 10_000);
3811 fn disable_channels_test() {
3812 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3813 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3814 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3815 let scorer = ln_test_utils::TestScorer::new();
3816 let random_seed_bytes = [42; 32];
3818 // // Disable channels 4 and 12 by flags=2
3819 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3820 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3821 short_channel_id: 4,
3823 flags: 2, // to disable
3824 cltv_expiry_delta: 0,
3825 htlc_minimum_msat: 0,
3826 htlc_maximum_msat: MAX_VALUE_MSAT,
3828 fee_proportional_millionths: 0,
3829 excess_data: Vec::new()
3831 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3832 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
3833 short_channel_id: 12,
3835 flags: 2, // to disable
3836 cltv_expiry_delta: 0,
3837 htlc_minimum_msat: 0,
3838 htlc_maximum_msat: MAX_VALUE_MSAT,
3840 fee_proportional_millionths: 0,
3841 excess_data: Vec::new()
3844 // If all the channels require some features we don't understand, route should fail
3845 let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3846 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3847 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
3848 &Default::default(), &random_seed_bytes) {
3849 assert_eq!(err, "Failed to find a path to the given destination");
3850 } else { panic!(); }
3852 // If we specify a channel to node7, that overrides our local channel view and that gets used
3853 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
3854 InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3855 route_params.payment_params.max_path_length = 2;
3856 let route = get_route(&our_id, &route_params, &network_graph.read_only(),
3857 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
3858 &Default::default(), &random_seed_bytes).unwrap();
3859 assert_eq!(route.paths[0].hops.len(), 2);
3861 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3862 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3863 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3864 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3865 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
3866 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3868 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3869 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3870 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3871 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3872 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3873 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3877 fn disable_node_test() {
3878 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3879 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3880 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3881 let scorer = ln_test_utils::TestScorer::new();
3882 let random_seed_bytes = [42; 32];
3884 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
3885 let mut unknown_features = NodeFeatures::empty();
3886 unknown_features.set_unknown_feature_required();
3887 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
3888 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
3889 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
3891 // If all nodes require some features we don't understand, route should fail
3892 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3893 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
3894 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
3895 &Default::default(), &random_seed_bytes) {
3896 assert_eq!(err, "Failed to find a path to the given destination");
3897 } else { panic!(); }
3899 // If we specify a channel to node7, that overrides our local channel view and that gets used
3900 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
3901 InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3902 let route = get_route(&our_id, &route_params, &network_graph.read_only(),
3903 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
3904 &Default::default(), &random_seed_bytes).unwrap();
3905 assert_eq!(route.paths[0].hops.len(), 2);
3907 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3908 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3909 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3910 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3911 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
3912 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3914 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3915 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3916 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3917 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3918 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3919 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3921 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
3922 // naively) assume that the user checked the feature bits on the invoice, which override
3923 // the node_announcement.
3927 fn our_chans_test() {
3928 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3929 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3930 let scorer = ln_test_utils::TestScorer::new();
3931 let random_seed_bytes = [42; 32];
3933 // Route to 1 via 2 and 3 because our channel to 1 is disabled
3934 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
3935 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3936 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
3937 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
3938 assert_eq!(route.paths[0].hops.len(), 3);
3940 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3941 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3942 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3943 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3944 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3945 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3947 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3948 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3949 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3950 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (3 << 4) | 2);
3951 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3952 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3954 assert_eq!(route.paths[0].hops[2].pubkey, nodes[0]);
3955 assert_eq!(route.paths[0].hops[2].short_channel_id, 3);
3956 assert_eq!(route.paths[0].hops[2].fee_msat, 100);
3957 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
3958 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(1));
3959 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(3));
3961 // If we specify a channel to node7, that overrides our local channel view and that gets used
3962 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3963 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
3964 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(),
3965 InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3966 let route = get_route(&our_id, &route_params, &network_graph.read_only(),
3967 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
3968 &Default::default(), &random_seed_bytes).unwrap();
3969 assert_eq!(route.paths[0].hops.len(), 2);
3971 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3972 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3973 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3974 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3975 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3976 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3978 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3979 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3980 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3981 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3982 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3983 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3986 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3987 let zero_fees = RoutingFees {
3989 proportional_millionths: 0,
3991 vec![RouteHint(vec![RouteHintHop {
3992 src_node_id: nodes[3],
3993 short_channel_id: 8,
3995 cltv_expiry_delta: (8 << 4) | 1,
3996 htlc_minimum_msat: None,
3997 htlc_maximum_msat: None,
3999 ]), RouteHint(vec![RouteHintHop {
4000 src_node_id: nodes[4],
4001 short_channel_id: 9,
4004 proportional_millionths: 0,
4006 cltv_expiry_delta: (9 << 4) | 1,
4007 htlc_minimum_msat: None,
4008 htlc_maximum_msat: None,
4009 }]), RouteHint(vec![RouteHintHop {
4010 src_node_id: nodes[5],
4011 short_channel_id: 10,
4013 cltv_expiry_delta: (10 << 4) | 1,
4014 htlc_minimum_msat: None,
4015 htlc_maximum_msat: None,
4019 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
4020 let zero_fees = RoutingFees {
4022 proportional_millionths: 0,
4024 vec![RouteHint(vec![RouteHintHop {
4025 src_node_id: nodes[2],
4026 short_channel_id: 5,
4029 proportional_millionths: 0,
4031 cltv_expiry_delta: (5 << 4) | 1,
4032 htlc_minimum_msat: None,
4033 htlc_maximum_msat: None,
4035 src_node_id: nodes[3],
4036 short_channel_id: 8,
4038 cltv_expiry_delta: (8 << 4) | 1,
4039 htlc_minimum_msat: None,
4040 htlc_maximum_msat: None,
4042 ]), RouteHint(vec![RouteHintHop {
4043 src_node_id: nodes[4],
4044 short_channel_id: 9,
4047 proportional_millionths: 0,
4049 cltv_expiry_delta: (9 << 4) | 1,
4050 htlc_minimum_msat: None,
4051 htlc_maximum_msat: None,
4052 }]), RouteHint(vec![RouteHintHop {
4053 src_node_id: nodes[5],
4054 short_channel_id: 10,
4056 cltv_expiry_delta: (10 << 4) | 1,
4057 htlc_minimum_msat: None,
4058 htlc_maximum_msat: None,
4063 fn partial_route_hint_test() {
4064 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4065 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4066 let scorer = ln_test_utils::TestScorer::new();
4067 let random_seed_bytes = [42; 32];
4069 // Simple test across 2, 3, 5, and 4 via a last_hop channel
4070 // Tests the behaviour when the RouteHint contains a suboptimal hop.
4071 // RouteHint may be partially used by the algo to build the best path.
4073 // First check that last hop can't have its source as the payee.
4074 let invalid_last_hop = RouteHint(vec![RouteHintHop {
4075 src_node_id: nodes[6],
4076 short_channel_id: 8,
4079 proportional_millionths: 0,
4081 cltv_expiry_delta: (8 << 4) | 1,
4082 htlc_minimum_msat: None,
4083 htlc_maximum_msat: None,
4086 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
4087 invalid_last_hops.push(invalid_last_hop);
4089 let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
4090 .with_route_hints(invalid_last_hops).unwrap();
4091 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4092 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
4093 &route_params, &network_graph.read_only(), None, Arc::clone(&logger), &scorer,
4094 &Default::default(), &random_seed_bytes) {
4095 assert_eq!(err, "Route hint cannot have the payee as the source.");
4096 } else { panic!(); }
4099 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 42)
4100 .with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
4101 payment_params.max_path_length = 5;
4102 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4103 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4104 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4105 assert_eq!(route.paths[0].hops.len(), 5);
4107 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4108 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4109 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
4110 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
4111 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4112 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4114 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4115 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4116 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
4117 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
4118 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4119 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4121 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
4122 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
4123 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4124 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
4125 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
4126 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
4128 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
4129 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
4130 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
4131 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
4132 // If we have a peer in the node map, we'll use their features here since we don't have
4133 // a way of figuring out their features from the invoice:
4134 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
4135 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
4137 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
4138 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
4139 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
4140 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
4141 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4142 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4145 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
4146 let zero_fees = RoutingFees {
4148 proportional_millionths: 0,
4150 vec![RouteHint(vec![RouteHintHop {
4151 src_node_id: nodes[3],
4152 short_channel_id: 8,
4154 cltv_expiry_delta: (8 << 4) | 1,
4155 htlc_minimum_msat: None,
4156 htlc_maximum_msat: None,
4157 }]), RouteHint(vec![
4159 ]), RouteHint(vec![RouteHintHop {
4160 src_node_id: nodes[5],
4161 short_channel_id: 10,
4163 cltv_expiry_delta: (10 << 4) | 1,
4164 htlc_minimum_msat: None,
4165 htlc_maximum_msat: None,
4170 fn ignores_empty_last_hops_test() {
4171 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4172 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4173 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes)).unwrap();
4174 let scorer = ln_test_utils::TestScorer::new();
4175 let random_seed_bytes = [42; 32];
4177 // Test handling of an empty RouteHint passed in Invoice.
4178 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4179 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4180 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4181 assert_eq!(route.paths[0].hops.len(), 5);
4183 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4184 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4185 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
4186 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
4187 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4188 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4190 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4191 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4192 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
4193 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
4194 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4195 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4197 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
4198 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
4199 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4200 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
4201 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
4202 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
4204 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
4205 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
4206 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
4207 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
4208 // If we have a peer in the node map, we'll use their features here since we don't have
4209 // a way of figuring out their features from the invoice:
4210 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
4211 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
4213 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
4214 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
4215 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
4216 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
4217 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4218 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4221 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
4223 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
4224 let zero_fees = RoutingFees {
4226 proportional_millionths: 0,
4228 vec![RouteHint(vec![RouteHintHop {
4229 src_node_id: hint_hops[0],
4230 short_channel_id: 0xff00,
4233 proportional_millionths: 0,
4235 cltv_expiry_delta: (5 << 4) | 1,
4236 htlc_minimum_msat: None,
4237 htlc_maximum_msat: None,
4239 src_node_id: hint_hops[1],
4240 short_channel_id: 0xff01,
4242 cltv_expiry_delta: (8 << 4) | 1,
4243 htlc_minimum_msat: None,
4244 htlc_maximum_msat: None,
4249 fn multi_hint_last_hops_test() {
4250 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4251 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4252 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
4253 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
4254 let scorer = ln_test_utils::TestScorer::new();
4255 let random_seed_bytes = [42; 32];
4257 // Test through channels 2, 3, 0xff00, 0xff01.
4258 // Test shows that multi-hop route hints are considered and factored correctly into the
4261 // Disabling channels 6 & 7 by flags=2
4262 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4263 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4264 short_channel_id: 6,
4266 flags: 2, // to disable
4267 cltv_expiry_delta: 0,
4268 htlc_minimum_msat: 0,
4269 htlc_maximum_msat: MAX_VALUE_MSAT,
4271 fee_proportional_millionths: 0,
4272 excess_data: Vec::new()
4274 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4275 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4276 short_channel_id: 7,
4278 flags: 2, // to disable
4279 cltv_expiry_delta: 0,
4280 htlc_minimum_msat: 0,
4281 htlc_maximum_msat: MAX_VALUE_MSAT,
4283 fee_proportional_millionths: 0,
4284 excess_data: Vec::new()
4287 let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4288 route_params.payment_params.max_path_length = 4;
4289 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4290 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4291 assert_eq!(route.paths[0].hops.len(), 4);
4293 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4294 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4295 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
4296 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
4297 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4298 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4300 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4301 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4302 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
4303 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
4304 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4305 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4307 assert_eq!(route.paths[0].hops[2].pubkey, nodes[3]);
4308 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
4309 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4310 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
4311 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(4));
4312 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4314 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
4315 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
4316 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
4317 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
4318 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4319 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4320 route_params.payment_params.max_path_length = 3;
4321 get_route(&our_id, &route_params, &network_graph.read_only(), None,
4322 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap_err();
4326 fn private_multi_hint_last_hops_test() {
4327 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4328 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4330 let non_announced_privkey = SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
4331 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
4333 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
4334 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
4335 let scorer = ln_test_utils::TestScorer::new();
4336 // Test through channels 2, 3, 0xff00, 0xff01.
4337 // Test shows that multiple hop hints are considered.
4339 // Disabling channels 6 & 7 by flags=2
4340 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4341 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4342 short_channel_id: 6,
4344 flags: 2, // to disable
4345 cltv_expiry_delta: 0,
4346 htlc_minimum_msat: 0,
4347 htlc_maximum_msat: MAX_VALUE_MSAT,
4349 fee_proportional_millionths: 0,
4350 excess_data: Vec::new()
4352 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4353 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4354 short_channel_id: 7,
4356 flags: 2, // to disable
4357 cltv_expiry_delta: 0,
4358 htlc_minimum_msat: 0,
4359 htlc_maximum_msat: MAX_VALUE_MSAT,
4361 fee_proportional_millionths: 0,
4362 excess_data: Vec::new()
4365 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4366 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4367 Arc::clone(&logger), &scorer, &Default::default(), &[42u8; 32]).unwrap();
4368 assert_eq!(route.paths[0].hops.len(), 4);
4370 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4371 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4372 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
4373 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
4374 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4375 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4377 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4378 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4379 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
4380 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
4381 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4382 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4384 assert_eq!(route.paths[0].hops[2].pubkey, non_announced_pubkey);
4385 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
4386 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4387 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
4388 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4389 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4391 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
4392 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
4393 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
4394 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
4395 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4396 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4399 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
4400 let zero_fees = RoutingFees {
4402 proportional_millionths: 0,
4404 vec![RouteHint(vec![RouteHintHop {
4405 src_node_id: nodes[4],
4406 short_channel_id: 11,
4408 cltv_expiry_delta: (11 << 4) | 1,
4409 htlc_minimum_msat: None,
4410 htlc_maximum_msat: None,
4412 src_node_id: nodes[3],
4413 short_channel_id: 8,
4415 cltv_expiry_delta: (8 << 4) | 1,
4416 htlc_minimum_msat: None,
4417 htlc_maximum_msat: None,
4418 }]), RouteHint(vec![RouteHintHop {
4419 src_node_id: nodes[4],
4420 short_channel_id: 9,
4423 proportional_millionths: 0,
4425 cltv_expiry_delta: (9 << 4) | 1,
4426 htlc_minimum_msat: None,
4427 htlc_maximum_msat: None,
4428 }]), RouteHint(vec![RouteHintHop {
4429 src_node_id: nodes[5],
4430 short_channel_id: 10,
4432 cltv_expiry_delta: (10 << 4) | 1,
4433 htlc_minimum_msat: None,
4434 htlc_maximum_msat: None,
4439 fn last_hops_with_public_channel_test() {
4440 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4441 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4442 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes)).unwrap();
4443 let scorer = ln_test_utils::TestScorer::new();
4444 let random_seed_bytes = [42; 32];
4446 // This test shows that public routes can be present in the invoice
4447 // which would be handled in the same manner.
4449 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4450 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4451 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4452 assert_eq!(route.paths[0].hops.len(), 5);
4454 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4455 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4456 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
4457 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
4458 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4459 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4461 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4462 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4463 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
4464 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
4465 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4466 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4468 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
4469 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
4470 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4471 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
4472 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
4473 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
4475 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
4476 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
4477 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
4478 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
4479 // If we have a peer in the node map, we'll use their features here since we don't have
4480 // a way of figuring out their features from the invoice:
4481 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
4482 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
4484 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
4485 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
4486 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
4487 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
4488 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4489 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4493 fn our_chans_last_hop_connect_test() {
4494 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4495 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4496 let scorer = ln_test_utils::TestScorer::new();
4497 let random_seed_bytes = [42; 32];
4499 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
4500 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
4501 let mut last_hops = last_hops(&nodes);
4502 let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
4503 .with_route_hints(last_hops.clone()).unwrap();
4504 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
4505 let route = get_route(&our_id, &route_params, &network_graph.read_only(),
4506 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
4507 &Default::default(), &random_seed_bytes).unwrap();
4508 assert_eq!(route.paths[0].hops.len(), 2);
4510 assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
4511 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
4512 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
4513 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
4514 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
4515 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
4517 assert_eq!(route.paths[0].hops[1].pubkey, nodes[6]);
4518 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
4519 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
4520 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
4521 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4522 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4524 last_hops[0].0[0].fees.base_msat = 1000;
4526 // Revert to via 6 as the fee on 8 goes up
4527 let payment_params = PaymentParameters::from_node_id(nodes[6], 42)
4528 .with_route_hints(last_hops).unwrap();
4529 let route_params = RouteParameters::from_payment_params_and_value(
4530 payment_params.clone(), 100);
4531 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4532 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4533 assert_eq!(route.paths[0].hops.len(), 4);
4535 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4536 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4537 assert_eq!(route.paths[0].hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
4538 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
4539 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4540 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4542 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4543 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4544 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
4545 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (7 << 4) | 1);
4546 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4547 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4549 assert_eq!(route.paths[0].hops[2].pubkey, nodes[5]);
4550 assert_eq!(route.paths[0].hops[2].short_channel_id, 7);
4551 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4552 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (10 << 4) | 1);
4553 // If we have a peer in the node map, we'll use their features here since we don't have
4554 // a way of figuring out their features from the invoice:
4555 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
4556 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(7));
4558 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
4559 assert_eq!(route.paths[0].hops[3].short_channel_id, 10);
4560 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
4561 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
4562 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4563 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4565 // ...but still use 8 for larger payments as 6 has a variable feerate
4566 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 2000);
4567 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4568 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4569 assert_eq!(route.paths[0].hops.len(), 5);
4571 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4572 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
4573 assert_eq!(route.paths[0].hops[0].fee_msat, 3000);
4574 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
4575 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
4576 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
4578 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
4579 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
4580 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
4581 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
4582 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
4583 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
4585 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
4586 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
4587 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
4588 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
4589 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
4590 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
4592 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
4593 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
4594 assert_eq!(route.paths[0].hops[3].fee_msat, 1000);
4595 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
4596 // If we have a peer in the node map, we'll use their features here since we don't have
4597 // a way of figuring out their features from the invoice:
4598 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
4599 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
4601 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
4602 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
4603 assert_eq!(route.paths[0].hops[4].fee_msat, 2000);
4604 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
4605 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4606 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
4609 fn do_unannounced_path_test(last_hop_htlc_max: Option<u64>, last_hop_fee_prop: u32, outbound_capacity_msat: u64, route_val: u64) -> Result<Route, LightningError> {
4610 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
4611 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
4612 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
4614 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
4615 let last_hops = RouteHint(vec![RouteHintHop {
4616 src_node_id: middle_node_id,
4617 short_channel_id: 8,
4620 proportional_millionths: last_hop_fee_prop,
4622 cltv_expiry_delta: (8 << 4) | 1,
4623 htlc_minimum_msat: None,
4624 htlc_maximum_msat: last_hop_htlc_max,
4626 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]).unwrap();
4627 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
4628 let scorer = ln_test_utils::TestScorer::new();
4629 let random_seed_bytes = [42; 32];
4630 let logger = ln_test_utils::TestLogger::new();
4631 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
4632 let route_params = RouteParameters::from_payment_params_and_value(payment_params, route_val);
4633 let route = get_route(&source_node_id, &route_params, &network_graph.read_only(),
4634 Some(&our_chans.iter().collect::<Vec<_>>()), &logger, &scorer, &Default::default(),
4635 &random_seed_bytes);
4640 fn unannounced_path_test() {
4641 // We should be able to send a payment to a destination without any help of a routing graph
4642 // if we have a channel with a common counterparty that appears in the first and last hop
4644 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
4646 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
4647 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&<Vec<u8>>::from_hex(&format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
4648 assert_eq!(route.paths[0].hops.len(), 2);
4650 assert_eq!(route.paths[0].hops[0].pubkey, middle_node_id);
4651 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
4652 assert_eq!(route.paths[0].hops[0].fee_msat, 1001);
4653 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
4654 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &[0b11]);
4655 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
4657 assert_eq!(route.paths[0].hops[1].pubkey, target_node_id);
4658 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
4659 assert_eq!(route.paths[0].hops[1].fee_msat, 1000000);
4660 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
4661 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
4662 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
4666 fn overflow_unannounced_path_test_liquidity_underflow() {
4667 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
4668 // the last-hop had a fee which overflowed a u64, we'd panic.
4669 // This was due to us adding the first-hop from us unconditionally, causing us to think
4670 // we'd built a path (as our node is in the "best candidate" set), when we had not.
4671 // In this test, we previously hit a subtraction underflow due to having less available
4672 // liquidity at the last hop than 0.
4673 assert!(do_unannounced_path_test(Some(21_000_000_0000_0000_000), 0, 21_000_000_0000_0000_000, 21_000_000_0000_0000_000).is_err());
4677 fn overflow_unannounced_path_test_feerate_overflow() {
4678 // This tests for the same case as above, except instead of hitting a subtraction
4679 // underflow, we hit a case where the fee charged at a hop overflowed.
4680 assert!(do_unannounced_path_test(Some(21_000_000_0000_0000_000), 50000, 21_000_000_0000_0000_000, 21_000_000_0000_0000_000).is_err());
4684 fn available_amount_while_routing_test() {
4685 // Tests whether we choose the correct available channel amount while routing.
4687 let (secp_ctx, network_graph, gossip_sync, chain_monitor, logger) = build_graph();
4688 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4689 let scorer = ln_test_utils::TestScorer::new();
4690 let random_seed_bytes = [42; 32];
4691 let config = UserConfig::default();
4692 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
4693 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
4696 // We will use a simple single-path route from
4697 // our node to node2 via node0: channels {1, 3}.
4699 // First disable all other paths.
4700 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4701 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4702 short_channel_id: 2,
4705 cltv_expiry_delta: 0,
4706 htlc_minimum_msat: 0,
4707 htlc_maximum_msat: 100_000,
4709 fee_proportional_millionths: 0,
4710 excess_data: Vec::new()
4712 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4713 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4714 short_channel_id: 12,
4717 cltv_expiry_delta: 0,
4718 htlc_minimum_msat: 0,
4719 htlc_maximum_msat: 100_000,
4721 fee_proportional_millionths: 0,
4722 excess_data: Vec::new()
4725 // Make the first channel (#1) very permissive,
4726 // and we will be testing all limits on the second channel.
4727 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4728 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4729 short_channel_id: 1,
4732 cltv_expiry_delta: 0,
4733 htlc_minimum_msat: 0,
4734 htlc_maximum_msat: 1_000_000_000,
4736 fee_proportional_millionths: 0,
4737 excess_data: Vec::new()
4740 // First, let's see if routing works if we have absolutely no idea about the available amount.
4741 // In this case, it should be set to 250_000 sats.
4742 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4743 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4744 short_channel_id: 3,
4747 cltv_expiry_delta: 0,
4748 htlc_minimum_msat: 0,
4749 htlc_maximum_msat: 250_000_000,
4751 fee_proportional_millionths: 0,
4752 excess_data: Vec::new()
4756 // Attempt to route more than available results in a failure.
4757 let route_params = RouteParameters::from_payment_params_and_value(
4758 payment_params.clone(), 250_000_001);
4759 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4760 &our_id, &route_params, &network_graph.read_only(), None,
4761 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes) {
4762 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4763 } else { panic!(); }
4767 // Now, attempt to route an exact amount we have should be fine.
4768 let route_params = RouteParameters::from_payment_params_and_value(
4769 payment_params.clone(), 250_000_000);
4770 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4771 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4772 assert_eq!(route.paths.len(), 1);
4773 let path = route.paths.last().unwrap();
4774 assert_eq!(path.hops.len(), 2);
4775 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4776 assert_eq!(path.final_value_msat(), 250_000_000);
4779 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
4780 // Disable channel #1 and use another first hop.
4781 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4782 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4783 short_channel_id: 1,
4786 cltv_expiry_delta: 0,
4787 htlc_minimum_msat: 0,
4788 htlc_maximum_msat: 1_000_000_000,
4790 fee_proportional_millionths: 0,
4791 excess_data: Vec::new()
4794 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
4795 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
4798 // Attempt to route more than available results in a failure.
4799 let route_params = RouteParameters::from_payment_params_and_value(
4800 payment_params.clone(), 200_000_001);
4801 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4802 &our_id, &route_params, &network_graph.read_only(),
4803 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
4804 &Default::default(), &random_seed_bytes) {
4805 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4806 } else { panic!(); }
4810 // Now, attempt to route an exact amount we have should be fine.
4811 let route_params = RouteParameters::from_payment_params_and_value(
4812 payment_params.clone(), 200_000_000);
4813 let route = get_route(&our_id, &route_params, &network_graph.read_only(),
4814 Some(&our_chans.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
4815 &Default::default(), &random_seed_bytes).unwrap();
4816 assert_eq!(route.paths.len(), 1);
4817 let path = route.paths.last().unwrap();
4818 assert_eq!(path.hops.len(), 2);
4819 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4820 assert_eq!(path.final_value_msat(), 200_000_000);
4823 // Enable channel #1 back.
4824 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4825 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4826 short_channel_id: 1,
4829 cltv_expiry_delta: 0,
4830 htlc_minimum_msat: 0,
4831 htlc_maximum_msat: 1_000_000_000,
4833 fee_proportional_millionths: 0,
4834 excess_data: Vec::new()
4838 // Now let's see if routing works if we know only htlc_maximum_msat.
4839 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4840 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4841 short_channel_id: 3,
4844 cltv_expiry_delta: 0,
4845 htlc_minimum_msat: 0,
4846 htlc_maximum_msat: 15_000,
4848 fee_proportional_millionths: 0,
4849 excess_data: Vec::new()
4853 // Attempt to route more than available results in a failure.
4854 let route_params = RouteParameters::from_payment_params_and_value(
4855 payment_params.clone(), 15_001);
4856 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4857 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
4858 &scorer, &Default::default(), &random_seed_bytes) {
4859 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4860 } else { panic!(); }
4864 // Now, attempt to route an exact amount we have should be fine.
4865 let route_params = RouteParameters::from_payment_params_and_value(
4866 payment_params.clone(), 15_000);
4867 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4868 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4869 assert_eq!(route.paths.len(), 1);
4870 let path = route.paths.last().unwrap();
4871 assert_eq!(path.hops.len(), 2);
4872 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4873 assert_eq!(path.final_value_msat(), 15_000);
4876 // Now let's see if routing works if we know only capacity from the UTXO.
4878 // We can't change UTXO capacity on the fly, so we'll disable
4879 // the existing channel and add another one with the capacity we need.
4880 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4881 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4882 short_channel_id: 3,
4885 cltv_expiry_delta: 0,
4886 htlc_minimum_msat: 0,
4887 htlc_maximum_msat: MAX_VALUE_MSAT,
4889 fee_proportional_millionths: 0,
4890 excess_data: Vec::new()
4893 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
4894 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
4895 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
4896 .push_opcode(opcodes::all::OP_PUSHNUM_2)
4897 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_p2wsh();
4899 *chain_monitor.utxo_ret.lock().unwrap() =
4900 UtxoResult::Sync(Ok(TxOut { value: Amount::from_sat(15), script_pubkey: good_script.clone() }));
4901 gossip_sync.add_utxo_lookup(Some(chain_monitor));
4903 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
4904 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4905 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4906 short_channel_id: 333,
4909 cltv_expiry_delta: (3 << 4) | 1,
4910 htlc_minimum_msat: 0,
4911 htlc_maximum_msat: 15_000,
4913 fee_proportional_millionths: 0,
4914 excess_data: Vec::new()
4916 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4917 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4918 short_channel_id: 333,
4921 cltv_expiry_delta: (3 << 4) | 2,
4922 htlc_minimum_msat: 0,
4923 htlc_maximum_msat: 15_000,
4925 fee_proportional_millionths: 0,
4926 excess_data: Vec::new()
4930 // Attempt to route more than available results in a failure.
4931 let route_params = RouteParameters::from_payment_params_and_value(
4932 payment_params.clone(), 15_001);
4933 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4934 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
4935 &scorer, &Default::default(), &random_seed_bytes) {
4936 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4937 } else { panic!(); }
4941 // Now, attempt to route an exact amount we have should be fine.
4942 let route_params = RouteParameters::from_payment_params_and_value(
4943 payment_params.clone(), 15_000);
4944 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4945 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4946 assert_eq!(route.paths.len(), 1);
4947 let path = route.paths.last().unwrap();
4948 assert_eq!(path.hops.len(), 2);
4949 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4950 assert_eq!(path.final_value_msat(), 15_000);
4953 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
4954 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4955 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
4956 short_channel_id: 333,
4959 cltv_expiry_delta: 0,
4960 htlc_minimum_msat: 0,
4961 htlc_maximum_msat: 10_000,
4963 fee_proportional_millionths: 0,
4964 excess_data: Vec::new()
4968 // Attempt to route more than available results in a failure.
4969 let route_params = RouteParameters::from_payment_params_and_value(
4970 payment_params.clone(), 10_001);
4971 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4972 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
4973 &scorer, &Default::default(), &random_seed_bytes) {
4974 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4975 } else { panic!(); }
4979 // Now, attempt to route an exact amount we have should be fine.
4980 let route_params = RouteParameters::from_payment_params_and_value(
4981 payment_params.clone(), 10_000);
4982 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
4983 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
4984 assert_eq!(route.paths.len(), 1);
4985 let path = route.paths.last().unwrap();
4986 assert_eq!(path.hops.len(), 2);
4987 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4988 assert_eq!(path.final_value_msat(), 10_000);
4993 fn available_liquidity_last_hop_test() {
4994 // Check that available liquidity properly limits the path even when only
4995 // one of the latter hops is limited.
4996 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4997 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4998 let scorer = ln_test_utils::TestScorer::new();
4999 let random_seed_bytes = [42; 32];
5000 let config = UserConfig::default();
5001 let payment_params = PaymentParameters::from_node_id(nodes[3], 42)
5002 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
5005 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
5006 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
5007 // Total capacity: 50 sats.
5009 // Disable other potential paths.
5010 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5011 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5012 short_channel_id: 2,
5015 cltv_expiry_delta: 0,
5016 htlc_minimum_msat: 0,
5017 htlc_maximum_msat: 100_000,
5019 fee_proportional_millionths: 0,
5020 excess_data: Vec::new()
5022 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5023 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5024 short_channel_id: 7,
5027 cltv_expiry_delta: 0,
5028 htlc_minimum_msat: 0,
5029 htlc_maximum_msat: 100_000,
5031 fee_proportional_millionths: 0,
5032 excess_data: Vec::new()
5037 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5038 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5039 short_channel_id: 12,
5042 cltv_expiry_delta: 0,
5043 htlc_minimum_msat: 0,
5044 htlc_maximum_msat: 100_000,
5046 fee_proportional_millionths: 0,
5047 excess_data: Vec::new()
5049 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5050 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5051 short_channel_id: 13,
5054 cltv_expiry_delta: 0,
5055 htlc_minimum_msat: 0,
5056 htlc_maximum_msat: 100_000,
5058 fee_proportional_millionths: 0,
5059 excess_data: Vec::new()
5062 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5063 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5064 short_channel_id: 6,
5067 cltv_expiry_delta: 0,
5068 htlc_minimum_msat: 0,
5069 htlc_maximum_msat: 50_000,
5071 fee_proportional_millionths: 0,
5072 excess_data: Vec::new()
5074 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5075 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5076 short_channel_id: 11,
5079 cltv_expiry_delta: 0,
5080 htlc_minimum_msat: 0,
5081 htlc_maximum_msat: 100_000,
5083 fee_proportional_millionths: 0,
5084 excess_data: Vec::new()
5087 // Attempt to route more than available results in a failure.
5088 let route_params = RouteParameters::from_payment_params_and_value(
5089 payment_params.clone(), 60_000);
5090 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5091 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
5092 &scorer, &Default::default(), &random_seed_bytes) {
5093 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5094 } else { panic!(); }
5098 // Now, attempt to route 49 sats (just a bit below the capacity).
5099 let route_params = RouteParameters::from_payment_params_and_value(
5100 payment_params.clone(), 49_000);
5101 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5102 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5103 assert_eq!(route.paths.len(), 1);
5104 let mut total_amount_paid_msat = 0;
5105 for path in &route.paths {
5106 assert_eq!(path.hops.len(), 4);
5107 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5108 total_amount_paid_msat += path.final_value_msat();
5110 assert_eq!(total_amount_paid_msat, 49_000);
5114 // Attempt to route an exact amount is also fine
5115 let route_params = RouteParameters::from_payment_params_and_value(
5116 payment_params, 50_000);
5117 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5118 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5119 assert_eq!(route.paths.len(), 1);
5120 let mut total_amount_paid_msat = 0;
5121 for path in &route.paths {
5122 assert_eq!(path.hops.len(), 4);
5123 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5124 total_amount_paid_msat += path.final_value_msat();
5126 assert_eq!(total_amount_paid_msat, 50_000);
5131 fn ignore_fee_first_hop_test() {
5132 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5133 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5134 let scorer = ln_test_utils::TestScorer::new();
5135 let random_seed_bytes = [42; 32];
5136 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
5138 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
5139 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5140 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5141 short_channel_id: 1,
5144 cltv_expiry_delta: 0,
5145 htlc_minimum_msat: 0,
5146 htlc_maximum_msat: 100_000,
5147 fee_base_msat: 1_000_000,
5148 fee_proportional_millionths: 0,
5149 excess_data: Vec::new()
5151 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5152 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5153 short_channel_id: 3,
5156 cltv_expiry_delta: 0,
5157 htlc_minimum_msat: 0,
5158 htlc_maximum_msat: 50_000,
5160 fee_proportional_millionths: 0,
5161 excess_data: Vec::new()
5165 let route_params = RouteParameters::from_payment_params_and_value(
5166 payment_params, 50_000);
5167 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5168 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5169 assert_eq!(route.paths.len(), 1);
5170 let mut total_amount_paid_msat = 0;
5171 for path in &route.paths {
5172 assert_eq!(path.hops.len(), 2);
5173 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5174 total_amount_paid_msat += path.final_value_msat();
5176 assert_eq!(total_amount_paid_msat, 50_000);
5181 fn simple_mpp_route_test() {
5182 let (secp_ctx, _, _, _, _) = build_graph();
5183 let (_, _, _, nodes) = get_nodes(&secp_ctx);
5184 let config = UserConfig::default();
5185 let clear_payment_params = PaymentParameters::from_node_id(nodes[2], 42)
5186 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
5188 do_simple_mpp_route_test(clear_payment_params);
5190 // MPP to a 1-hop blinded path for nodes[2]
5191 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
5192 let blinded_path = BlindedPath {
5193 introduction_node: IntroductionNode::NodeId(nodes[2]),
5194 blinding_point: ln_test_utils::pubkey(42),
5195 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }],
5197 let blinded_payinfo = BlindedPayInfo { // These fields are ignored for 1-hop blinded paths
5199 fee_proportional_millionths: 0,
5200 htlc_minimum_msat: 0,
5201 htlc_maximum_msat: 0,
5202 cltv_expiry_delta: 0,
5203 features: BlindedHopFeatures::empty(),
5205 let one_hop_blinded_payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())])
5206 .with_bolt12_features(bolt12_features.clone()).unwrap();
5207 do_simple_mpp_route_test(one_hop_blinded_payment_params.clone());
5209 // MPP to 3 2-hop blinded paths
5210 let mut blinded_path_node_0 = blinded_path.clone();
5211 blinded_path_node_0.introduction_node = IntroductionNode::NodeId(nodes[0]);
5212 blinded_path_node_0.blinded_hops.push(blinded_path.blinded_hops[0].clone());
5213 let mut node_0_payinfo = blinded_payinfo.clone();
5214 node_0_payinfo.htlc_maximum_msat = 50_000;
5216 let mut blinded_path_node_7 = blinded_path_node_0.clone();
5217 blinded_path_node_7.introduction_node = IntroductionNode::NodeId(nodes[7]);
5218 let mut node_7_payinfo = blinded_payinfo.clone();
5219 node_7_payinfo.htlc_maximum_msat = 60_000;
5221 let mut blinded_path_node_1 = blinded_path_node_0.clone();
5222 blinded_path_node_1.introduction_node = IntroductionNode::NodeId(nodes[1]);
5223 let mut node_1_payinfo = blinded_payinfo.clone();
5224 node_1_payinfo.htlc_maximum_msat = 180_000;
5226 let two_hop_blinded_payment_params = PaymentParameters::blinded(
5228 (node_0_payinfo, blinded_path_node_0),
5229 (node_7_payinfo, blinded_path_node_7),
5230 (node_1_payinfo, blinded_path_node_1)
5232 .with_bolt12_features(bolt12_features).unwrap();
5233 do_simple_mpp_route_test(two_hop_blinded_payment_params);
5237 fn do_simple_mpp_route_test(payment_params: PaymentParameters) {
5238 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5239 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5240 let scorer = ln_test_utils::TestScorer::new();
5241 let random_seed_bytes = [42; 32];
5243 // We need a route consisting of 3 paths:
5244 // From our node to node2 via node0, node7, node1 (three paths one hop each).
5245 // To achieve this, the amount being transferred should be around
5246 // the total capacity of these 3 paths.
5248 // First, we set limits on these (previously unlimited) channels.
5249 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
5251 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
5252 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5253 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5254 short_channel_id: 1,
5257 cltv_expiry_delta: 0,
5258 htlc_minimum_msat: 0,
5259 htlc_maximum_msat: 100_000,
5261 fee_proportional_millionths: 0,
5262 excess_data: Vec::new()
5264 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5265 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5266 short_channel_id: 3,
5269 cltv_expiry_delta: 0,
5270 htlc_minimum_msat: 0,
5271 htlc_maximum_msat: 50_000,
5273 fee_proportional_millionths: 0,
5274 excess_data: Vec::new()
5277 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
5278 // (total limit 60).
5279 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5280 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5281 short_channel_id: 12,
5284 cltv_expiry_delta: 0,
5285 htlc_minimum_msat: 0,
5286 htlc_maximum_msat: 60_000,
5288 fee_proportional_millionths: 0,
5289 excess_data: Vec::new()
5291 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5292 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5293 short_channel_id: 13,
5296 cltv_expiry_delta: 0,
5297 htlc_minimum_msat: 0,
5298 htlc_maximum_msat: 60_000,
5300 fee_proportional_millionths: 0,
5301 excess_data: Vec::new()
5304 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
5305 // (total capacity 180 sats).
5306 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5307 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5308 short_channel_id: 2,
5311 cltv_expiry_delta: 0,
5312 htlc_minimum_msat: 0,
5313 htlc_maximum_msat: 200_000,
5315 fee_proportional_millionths: 0,
5316 excess_data: Vec::new()
5318 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5319 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5320 short_channel_id: 4,
5323 cltv_expiry_delta: 0,
5324 htlc_minimum_msat: 0,
5325 htlc_maximum_msat: 180_000,
5327 fee_proportional_millionths: 0,
5328 excess_data: Vec::new()
5332 // Attempt to route more than available results in a failure.
5333 let route_params = RouteParameters::from_payment_params_and_value(
5334 payment_params.clone(), 300_000);
5335 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5336 &our_id, &route_params, &network_graph.read_only(), None,
5337 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes) {
5338 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5339 } else { panic!(); }
5343 // Attempt to route while setting max_path_count to 0 results in a failure.
5344 let zero_payment_params = payment_params.clone().with_max_path_count(0);
5345 let route_params = RouteParameters::from_payment_params_and_value(
5346 zero_payment_params, 100);
5347 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5348 &our_id, &route_params, &network_graph.read_only(), None,
5349 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes) {
5350 assert_eq!(err, "Can't find a route with no paths allowed.");
5351 } else { panic!(); }
5355 // Attempt to route while setting max_path_count to 3 results in a failure.
5356 // This is the case because the minimal_value_contribution_msat would require each path
5357 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
5358 let fail_payment_params = payment_params.clone().with_max_path_count(3);
5359 let route_params = RouteParameters::from_payment_params_and_value(
5360 fail_payment_params, 250_000);
5361 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5362 &our_id, &route_params, &network_graph.read_only(), None,
5363 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes) {
5364 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5365 } else { panic!(); }
5369 // Now, attempt to route 250 sats (just a bit below the capacity).
5370 // Our algorithm should provide us with these 3 paths.
5371 let route_params = RouteParameters::from_payment_params_and_value(
5372 payment_params.clone(), 250_000);
5373 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5374 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5375 assert_eq!(route.paths.len(), 3);
5376 let mut total_amount_paid_msat = 0;
5377 for path in &route.paths {
5378 if let Some(bt) = &path.blinded_tail {
5379 assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
5381 assert_eq!(path.hops.len(), 2);
5382 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5384 total_amount_paid_msat += path.final_value_msat();
5386 assert_eq!(total_amount_paid_msat, 250_000);
5390 // Attempt to route an exact amount is also fine
5391 let route_params = RouteParameters::from_payment_params_and_value(
5392 payment_params.clone(), 290_000);
5393 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5394 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5395 assert_eq!(route.paths.len(), 3);
5396 let mut total_amount_paid_msat = 0;
5397 for path in &route.paths {
5398 if payment_params.payee.blinded_route_hints().len() != 0 {
5399 assert!(path.blinded_tail.is_some()) } else { assert!(path.blinded_tail.is_none()) }
5400 if let Some(bt) = &path.blinded_tail {
5401 assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
5402 if bt.hops.len() > 1 {
5403 let network_graph = network_graph.read_only();
5405 NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
5406 payment_params.payee.blinded_route_hints().iter()
5407 .find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
5408 .and_then(|(_, p)| p.public_introduction_node_id(&network_graph))
5413 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5416 assert_eq!(path.hops.len(), 2);
5417 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5419 total_amount_paid_msat += path.final_value_msat();
5421 assert_eq!(total_amount_paid_msat, 290_000);
5426 fn long_mpp_route_test() {
5427 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5428 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5429 let scorer = ln_test_utils::TestScorer::new();
5430 let random_seed_bytes = [42; 32];
5431 let config = UserConfig::default();
5432 let payment_params = PaymentParameters::from_node_id(nodes[3], 42)
5433 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
5436 // We need a route consisting of 3 paths:
5437 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
5438 // Note that these paths overlap (channels 5, 12, 13).
5439 // We will route 300 sats.
5440 // Each path will have 100 sats capacity, those channels which
5441 // are used twice will have 200 sats capacity.
5443 // Disable other potential paths.
5444 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5445 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5446 short_channel_id: 2,
5449 cltv_expiry_delta: 0,
5450 htlc_minimum_msat: 0,
5451 htlc_maximum_msat: 100_000,
5453 fee_proportional_millionths: 0,
5454 excess_data: Vec::new()
5456 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5457 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5458 short_channel_id: 7,
5461 cltv_expiry_delta: 0,
5462 htlc_minimum_msat: 0,
5463 htlc_maximum_msat: 100_000,
5465 fee_proportional_millionths: 0,
5466 excess_data: Vec::new()
5469 // Path via {node0, node2} is channels {1, 3, 5}.
5470 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5471 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5472 short_channel_id: 1,
5475 cltv_expiry_delta: 0,
5476 htlc_minimum_msat: 0,
5477 htlc_maximum_msat: 100_000,
5479 fee_proportional_millionths: 0,
5480 excess_data: Vec::new()
5482 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5483 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5484 short_channel_id: 3,
5487 cltv_expiry_delta: 0,
5488 htlc_minimum_msat: 0,
5489 htlc_maximum_msat: 100_000,
5491 fee_proportional_millionths: 0,
5492 excess_data: Vec::new()
5495 // Capacity of 200 sats because this channel will be used by 3rd path as well.
5496 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5497 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5498 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5499 short_channel_id: 5,
5502 cltv_expiry_delta: 0,
5503 htlc_minimum_msat: 0,
5504 htlc_maximum_msat: 200_000,
5506 fee_proportional_millionths: 0,
5507 excess_data: Vec::new()
5509 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5510 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5511 short_channel_id: 5,
5513 flags: 3, // disable direction 1
5514 cltv_expiry_delta: 0,
5515 htlc_minimum_msat: 0,
5516 htlc_maximum_msat: 200_000,
5518 fee_proportional_millionths: 0,
5519 excess_data: Vec::new()
5522 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
5523 // Add 100 sats to the capacities of {12, 13}, because these channels
5524 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
5525 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5526 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5527 short_channel_id: 12,
5530 cltv_expiry_delta: 0,
5531 htlc_minimum_msat: 0,
5532 htlc_maximum_msat: 200_000,
5534 fee_proportional_millionths: 0,
5535 excess_data: Vec::new()
5537 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5538 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5539 short_channel_id: 13,
5542 cltv_expiry_delta: 0,
5543 htlc_minimum_msat: 0,
5544 htlc_maximum_msat: 200_000,
5546 fee_proportional_millionths: 0,
5547 excess_data: Vec::new()
5550 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5551 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5552 short_channel_id: 6,
5555 cltv_expiry_delta: 0,
5556 htlc_minimum_msat: 0,
5557 htlc_maximum_msat: 100_000,
5559 fee_proportional_millionths: 0,
5560 excess_data: Vec::new()
5562 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5563 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5564 short_channel_id: 11,
5567 cltv_expiry_delta: 0,
5568 htlc_minimum_msat: 0,
5569 htlc_maximum_msat: 100_000,
5571 fee_proportional_millionths: 0,
5572 excess_data: Vec::new()
5575 // Path via {node7, node2} is channels {12, 13, 5}.
5576 // We already limited them to 200 sats (they are used twice for 100 sats).
5577 // Nothing to do here.
5580 // Attempt to route more than available results in a failure.
5581 let route_params = RouteParameters::from_payment_params_and_value(
5582 payment_params.clone(), 350_000);
5583 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5584 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
5585 &scorer, &Default::default(), &random_seed_bytes) {
5586 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5587 } else { panic!(); }
5591 // Now, attempt to route 300 sats (exact amount we can route).
5592 // Our algorithm should provide us with these 3 paths, 100 sats each.
5593 let route_params = RouteParameters::from_payment_params_and_value(
5594 payment_params, 300_000);
5595 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5596 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5597 assert_eq!(route.paths.len(), 3);
5599 let mut total_amount_paid_msat = 0;
5600 for path in &route.paths {
5601 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5602 total_amount_paid_msat += path.final_value_msat();
5604 assert_eq!(total_amount_paid_msat, 300_000);
5610 fn mpp_cheaper_route_test() {
5611 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5612 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5613 let scorer = ln_test_utils::TestScorer::new();
5614 let random_seed_bytes = [42; 32];
5615 let config = UserConfig::default();
5616 let payment_params = PaymentParameters::from_node_id(nodes[3], 42)
5617 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
5620 // This test checks that if we have two cheaper paths and one more expensive path,
5621 // so that liquidity-wise any 2 of 3 combination is sufficient,
5622 // two cheaper paths will be taken.
5623 // These paths have equal available liquidity.
5625 // We need a combination of 3 paths:
5626 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
5627 // Note that these paths overlap (channels 5, 12, 13).
5628 // Each path will have 100 sats capacity, those channels which
5629 // are used twice will have 200 sats capacity.
5631 // Disable other potential paths.
5632 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5633 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5634 short_channel_id: 2,
5637 cltv_expiry_delta: 0,
5638 htlc_minimum_msat: 0,
5639 htlc_maximum_msat: 100_000,
5641 fee_proportional_millionths: 0,
5642 excess_data: Vec::new()
5644 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5645 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5646 short_channel_id: 7,
5649 cltv_expiry_delta: 0,
5650 htlc_minimum_msat: 0,
5651 htlc_maximum_msat: 100_000,
5653 fee_proportional_millionths: 0,
5654 excess_data: Vec::new()
5657 // Path via {node0, node2} is channels {1, 3, 5}.
5658 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5659 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5660 short_channel_id: 1,
5663 cltv_expiry_delta: 0,
5664 htlc_minimum_msat: 0,
5665 htlc_maximum_msat: 100_000,
5667 fee_proportional_millionths: 0,
5668 excess_data: Vec::new()
5670 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5671 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5672 short_channel_id: 3,
5675 cltv_expiry_delta: 0,
5676 htlc_minimum_msat: 0,
5677 htlc_maximum_msat: 100_000,
5679 fee_proportional_millionths: 0,
5680 excess_data: Vec::new()
5683 // Capacity of 200 sats because this channel will be used by 3rd path as well.
5684 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5685 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5686 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5687 short_channel_id: 5,
5690 cltv_expiry_delta: 0,
5691 htlc_minimum_msat: 0,
5692 htlc_maximum_msat: 200_000,
5694 fee_proportional_millionths: 0,
5695 excess_data: Vec::new()
5697 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5698 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5699 short_channel_id: 5,
5701 flags: 3, // disable direction 1
5702 cltv_expiry_delta: 0,
5703 htlc_minimum_msat: 0,
5704 htlc_maximum_msat: 200_000,
5706 fee_proportional_millionths: 0,
5707 excess_data: Vec::new()
5710 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
5711 // Add 100 sats to the capacities of {12, 13}, because these channels
5712 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
5713 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5714 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5715 short_channel_id: 12,
5718 cltv_expiry_delta: 0,
5719 htlc_minimum_msat: 0,
5720 htlc_maximum_msat: 200_000,
5722 fee_proportional_millionths: 0,
5723 excess_data: Vec::new()
5725 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5726 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5727 short_channel_id: 13,
5730 cltv_expiry_delta: 0,
5731 htlc_minimum_msat: 0,
5732 htlc_maximum_msat: 200_000,
5734 fee_proportional_millionths: 0,
5735 excess_data: Vec::new()
5738 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5739 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5740 short_channel_id: 6,
5743 cltv_expiry_delta: 0,
5744 htlc_minimum_msat: 0,
5745 htlc_maximum_msat: 100_000,
5746 fee_base_msat: 1_000,
5747 fee_proportional_millionths: 0,
5748 excess_data: Vec::new()
5750 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5751 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5752 short_channel_id: 11,
5755 cltv_expiry_delta: 0,
5756 htlc_minimum_msat: 0,
5757 htlc_maximum_msat: 100_000,
5759 fee_proportional_millionths: 0,
5760 excess_data: Vec::new()
5763 // Path via {node7, node2} is channels {12, 13, 5}.
5764 // We already limited them to 200 sats (they are used twice for 100 sats).
5765 // Nothing to do here.
5768 // Now, attempt to route 180 sats.
5769 // Our algorithm should provide us with these 2 paths.
5770 let route_params = RouteParameters::from_payment_params_and_value(
5771 payment_params, 180_000);
5772 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5773 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5774 assert_eq!(route.paths.len(), 2);
5776 let mut total_value_transferred_msat = 0;
5777 let mut total_paid_msat = 0;
5778 for path in &route.paths {
5779 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5780 total_value_transferred_msat += path.final_value_msat();
5781 for hop in &path.hops {
5782 total_paid_msat += hop.fee_msat;
5785 // If we paid fee, this would be higher.
5786 assert_eq!(total_value_transferred_msat, 180_000);
5787 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
5788 assert_eq!(total_fees_paid, 0);
5793 fn fees_on_mpp_route_test() {
5794 // This test makes sure that MPP algorithm properly takes into account
5795 // fees charged on the channels, by making the fees impactful:
5796 // if the fee is not properly accounted for, the behavior is different.
5797 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5798 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5799 let scorer = ln_test_utils::TestScorer::new();
5800 let random_seed_bytes = [42; 32];
5801 let config = UserConfig::default();
5802 let payment_params = PaymentParameters::from_node_id(nodes[3], 42)
5803 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
5806 // We need a route consisting of 2 paths:
5807 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
5808 // We will route 200 sats, Each path will have 100 sats capacity.
5810 // This test is not particularly stable: e.g.,
5811 // there's a way to route via {node0, node2, node4}.
5812 // It works while pathfinding is deterministic, but can be broken otherwise.
5813 // It's fine to ignore this concern for now.
5815 // Disable other potential paths.
5816 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5817 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5818 short_channel_id: 2,
5821 cltv_expiry_delta: 0,
5822 htlc_minimum_msat: 0,
5823 htlc_maximum_msat: 100_000,
5825 fee_proportional_millionths: 0,
5826 excess_data: Vec::new()
5829 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5830 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5831 short_channel_id: 7,
5834 cltv_expiry_delta: 0,
5835 htlc_minimum_msat: 0,
5836 htlc_maximum_msat: 100_000,
5838 fee_proportional_millionths: 0,
5839 excess_data: Vec::new()
5842 // Path via {node0, node2} is channels {1, 3, 5}.
5843 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5844 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5845 short_channel_id: 1,
5848 cltv_expiry_delta: 0,
5849 htlc_minimum_msat: 0,
5850 htlc_maximum_msat: 100_000,
5852 fee_proportional_millionths: 0,
5853 excess_data: Vec::new()
5855 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5856 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5857 short_channel_id: 3,
5860 cltv_expiry_delta: 0,
5861 htlc_minimum_msat: 0,
5862 htlc_maximum_msat: 100_000,
5864 fee_proportional_millionths: 0,
5865 excess_data: Vec::new()
5868 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5869 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5870 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5871 short_channel_id: 5,
5874 cltv_expiry_delta: 0,
5875 htlc_minimum_msat: 0,
5876 htlc_maximum_msat: 100_000,
5878 fee_proportional_millionths: 0,
5879 excess_data: Vec::new()
5881 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5882 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5883 short_channel_id: 5,
5885 flags: 3, // Disable direction 1
5886 cltv_expiry_delta: 0,
5887 htlc_minimum_msat: 0,
5888 htlc_maximum_msat: 100_000,
5890 fee_proportional_millionths: 0,
5891 excess_data: Vec::new()
5894 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
5895 // All channels should be 100 sats capacity. But for the fee experiment,
5896 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
5897 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
5898 // 100 sats (and pay 150 sats in fees for the use of channel 6),
5899 // so no matter how large are other channels,
5900 // the whole path will be limited by 100 sats with just these 2 conditions:
5901 // - channel 12 capacity is 250 sats
5902 // - fee for channel 6 is 150 sats
5903 // Let's test this by enforcing these 2 conditions and removing other limits.
5904 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5905 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5906 short_channel_id: 12,
5909 cltv_expiry_delta: 0,
5910 htlc_minimum_msat: 0,
5911 htlc_maximum_msat: 250_000,
5913 fee_proportional_millionths: 0,
5914 excess_data: Vec::new()
5916 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5917 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5918 short_channel_id: 13,
5921 cltv_expiry_delta: 0,
5922 htlc_minimum_msat: 0,
5923 htlc_maximum_msat: MAX_VALUE_MSAT,
5925 fee_proportional_millionths: 0,
5926 excess_data: Vec::new()
5929 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5930 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5931 short_channel_id: 6,
5934 cltv_expiry_delta: 0,
5935 htlc_minimum_msat: 0,
5936 htlc_maximum_msat: MAX_VALUE_MSAT,
5937 fee_base_msat: 150_000,
5938 fee_proportional_millionths: 0,
5939 excess_data: Vec::new()
5941 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5942 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
5943 short_channel_id: 11,
5946 cltv_expiry_delta: 0,
5947 htlc_minimum_msat: 0,
5948 htlc_maximum_msat: MAX_VALUE_MSAT,
5950 fee_proportional_millionths: 0,
5951 excess_data: Vec::new()
5955 // Attempt to route more than available results in a failure.
5956 let route_params = RouteParameters::from_payment_params_and_value(
5957 payment_params.clone(), 210_000);
5958 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5959 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
5960 &scorer, &Default::default(), &random_seed_bytes) {
5961 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5962 } else { panic!(); }
5966 // Attempt to route while setting max_total_routing_fee_msat to 149_999 results in a failure.
5967 let route_params = RouteParameters { payment_params: payment_params.clone(), final_value_msat: 200_000,
5968 max_total_routing_fee_msat: Some(149_999) };
5969 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5970 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
5971 &scorer, &Default::default(), &random_seed_bytes) {
5972 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5973 } else { panic!(); }
5977 // Now, attempt to route 200 sats (exact amount we can route).
5978 let route_params = RouteParameters { payment_params: payment_params.clone(), final_value_msat: 200_000,
5979 max_total_routing_fee_msat: Some(150_000) };
5980 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
5981 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
5982 assert_eq!(route.paths.len(), 2);
5984 let mut total_amount_paid_msat = 0;
5985 for path in &route.paths {
5986 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5987 total_amount_paid_msat += path.final_value_msat();
5989 assert_eq!(total_amount_paid_msat, 200_000);
5990 assert_eq!(route.get_total_fees(), 150_000);
5995 fn mpp_with_last_hops() {
5996 // Previously, if we tried to send an MPP payment to a destination which was only reachable
5997 // via a single last-hop route hint, we'd fail to route if we first collected routes
5998 // totaling close but not quite enough to fund the full payment.
6000 // This was because we considered last-hop hints to have exactly the sought payment amount
6001 // instead of the amount we were trying to collect, needlessly limiting our path searching
6002 // at the very first hop.
6004 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
6005 // criterion to cause us to refuse all routes at the last hop hint which would be considered
6006 // to only have the remaining to-collect amount in available liquidity.
6008 // This bug appeared in production in some specific channel configurations.
6009 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
6010 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
6011 let scorer = ln_test_utils::TestScorer::new();
6012 let random_seed_bytes = [42; 32];
6013 let config = UserConfig::default();
6014 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42)
6015 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap()
6016 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
6017 src_node_id: nodes[2],
6018 short_channel_id: 42,
6019 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
6020 cltv_expiry_delta: 42,
6021 htlc_minimum_msat: None,
6022 htlc_maximum_msat: None,
6023 }])]).unwrap().with_max_channel_saturation_power_of_half(0);
6025 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
6026 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
6027 // would first use the no-fee route and then fail to find a path along the second route as
6028 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
6029 // under 5% of our payment amount.
6030 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6031 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6032 short_channel_id: 1,
6035 cltv_expiry_delta: (5 << 4) | 5,
6036 htlc_minimum_msat: 0,
6037 htlc_maximum_msat: 99_000,
6038 fee_base_msat: u32::max_value(),
6039 fee_proportional_millionths: u32::max_value(),
6040 excess_data: Vec::new()
6042 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6043 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6044 short_channel_id: 2,
6047 cltv_expiry_delta: (5 << 4) | 3,
6048 htlc_minimum_msat: 0,
6049 htlc_maximum_msat: 99_000,
6050 fee_base_msat: u32::max_value(),
6051 fee_proportional_millionths: u32::max_value(),
6052 excess_data: Vec::new()
6054 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
6055 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6056 short_channel_id: 4,
6059 cltv_expiry_delta: (4 << 4) | 1,
6060 htlc_minimum_msat: 0,
6061 htlc_maximum_msat: MAX_VALUE_MSAT,
6063 fee_proportional_millionths: 0,
6064 excess_data: Vec::new()
6066 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
6067 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6068 short_channel_id: 13,
6070 flags: 0|2, // Channel disabled
6071 cltv_expiry_delta: (13 << 4) | 1,
6072 htlc_minimum_msat: 0,
6073 htlc_maximum_msat: MAX_VALUE_MSAT,
6075 fee_proportional_millionths: 2000000,
6076 excess_data: Vec::new()
6079 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
6081 let route_params = RouteParameters::from_payment_params_and_value(
6082 payment_params, 100_000);
6083 let mut route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6084 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6085 assert_eq!(route.paths.len(), 2);
6086 route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
6087 // Paths are manually ordered ordered by SCID, so:
6088 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
6089 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
6090 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
6091 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
6092 assert_eq!(route.paths[0].hops[2].fee_msat, 99_000);
6093 assert_eq!(route.paths[1].hops[0].short_channel_id, 2);
6094 assert_eq!(route.paths[1].hops[0].fee_msat, 1);
6095 assert_eq!(route.paths[1].hops[2].fee_msat, 1_000);
6096 assert_eq!(route.get_total_fees(), 1);
6097 assert_eq!(route.get_total_amount(), 100_000);
6101 fn drop_lowest_channel_mpp_route_test() {
6102 // This test checks that low-capacity channel is dropped when after
6103 // path finding we realize that we found more capacity than we need.
6104 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
6105 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
6106 let scorer = ln_test_utils::TestScorer::new();
6107 let random_seed_bytes = [42; 32];
6108 let config = UserConfig::default();
6109 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
6110 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
6112 .with_max_channel_saturation_power_of_half(0);
6114 // We need a route consisting of 3 paths:
6115 // From our node to node2 via node0, node7, node1 (three paths one hop each).
6117 // The first and the second paths should be sufficient, but the third should be
6118 // cheaper, so that we select it but drop later.
6120 // First, we set limits on these (previously unlimited) channels.
6121 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
6123 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
6124 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6125 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6126 short_channel_id: 1,
6129 cltv_expiry_delta: 0,
6130 htlc_minimum_msat: 0,
6131 htlc_maximum_msat: 100_000,
6133 fee_proportional_millionths: 0,
6134 excess_data: Vec::new()
6136 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
6137 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6138 short_channel_id: 3,
6141 cltv_expiry_delta: 0,
6142 htlc_minimum_msat: 0,
6143 htlc_maximum_msat: 50_000,
6145 fee_proportional_millionths: 0,
6146 excess_data: Vec::new()
6149 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
6150 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6151 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6152 short_channel_id: 12,
6155 cltv_expiry_delta: 0,
6156 htlc_minimum_msat: 0,
6157 htlc_maximum_msat: 60_000,
6159 fee_proportional_millionths: 0,
6160 excess_data: Vec::new()
6162 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
6163 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6164 short_channel_id: 13,
6167 cltv_expiry_delta: 0,
6168 htlc_minimum_msat: 0,
6169 htlc_maximum_msat: 60_000,
6171 fee_proportional_millionths: 0,
6172 excess_data: Vec::new()
6175 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
6176 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6177 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6178 short_channel_id: 2,
6181 cltv_expiry_delta: 0,
6182 htlc_minimum_msat: 0,
6183 htlc_maximum_msat: 20_000,
6185 fee_proportional_millionths: 0,
6186 excess_data: Vec::new()
6188 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
6189 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6190 short_channel_id: 4,
6193 cltv_expiry_delta: 0,
6194 htlc_minimum_msat: 0,
6195 htlc_maximum_msat: 20_000,
6197 fee_proportional_millionths: 0,
6198 excess_data: Vec::new()
6202 // Attempt to route more than available results in a failure.
6203 let route_params = RouteParameters::from_payment_params_and_value(
6204 payment_params.clone(), 150_000);
6205 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
6206 &our_id, &route_params, &network_graph.read_only(), None, Arc::clone(&logger),
6207 &scorer, &Default::default(), &random_seed_bytes) {
6208 assert_eq!(err, "Failed to find a sufficient route to the given destination");
6209 } else { panic!(); }
6213 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
6214 // Our algorithm should provide us with these 3 paths.
6215 let route_params = RouteParameters::from_payment_params_and_value(
6216 payment_params.clone(), 125_000);
6217 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6218 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6219 assert_eq!(route.paths.len(), 3);
6220 let mut total_amount_paid_msat = 0;
6221 for path in &route.paths {
6222 assert_eq!(path.hops.len(), 2);
6223 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
6224 total_amount_paid_msat += path.final_value_msat();
6226 assert_eq!(total_amount_paid_msat, 125_000);
6230 // Attempt to route without the last small cheap channel
6231 let route_params = RouteParameters::from_payment_params_and_value(
6232 payment_params, 90_000);
6233 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6234 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6235 assert_eq!(route.paths.len(), 2);
6236 let mut total_amount_paid_msat = 0;
6237 for path in &route.paths {
6238 assert_eq!(path.hops.len(), 2);
6239 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
6240 total_amount_paid_msat += path.final_value_msat();
6242 assert_eq!(total_amount_paid_msat, 90_000);
6247 fn min_criteria_consistency() {
6248 // Test that we don't use an inconsistent metric between updating and walking nodes during
6249 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
6250 // was updated with a different criterion from the heap sorting, resulting in loops in
6251 // calculated paths. We test for that specific case here.
6253 // We construct a network that looks like this:
6255 // node2 -1(3)2- node3
6259 // node1 -1(5)2- node4 -1(1)2- node6
6265 // We create a loop on the side of our real path - our destination is node 6, with a
6266 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
6267 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
6268 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
6269 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
6270 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
6271 // "previous hop" being set to node 3, creating a loop in the path.
6272 let secp_ctx = Secp256k1::new();
6273 let logger = Arc::new(ln_test_utils::TestLogger::new());
6274 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
6275 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
6276 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
6277 let scorer = ln_test_utils::TestScorer::new();
6278 let random_seed_bytes = [42; 32];
6279 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
6281 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
6282 for (key, flags) in [(&our_privkey, 0), (&privkeys[1], 3)] {
6283 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6284 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6285 short_channel_id: 6,
6288 cltv_expiry_delta: (6 << 4) | 0,
6289 htlc_minimum_msat: 0,
6290 htlc_maximum_msat: MAX_VALUE_MSAT,
6292 fee_proportional_millionths: 0,
6293 excess_data: Vec::new()
6296 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
6298 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
6299 for (key, flags) in [(&privkeys[1], 0), (&privkeys[4], 3)] {
6300 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6301 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6302 short_channel_id: 5,
6305 cltv_expiry_delta: (5 << 4) | 0,
6306 htlc_minimum_msat: 0,
6307 htlc_maximum_msat: MAX_VALUE_MSAT,
6309 fee_proportional_millionths: 0,
6310 excess_data: Vec::new()
6313 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
6315 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
6316 for (key, flags) in [(&privkeys[4], 0), (&privkeys[3], 3)] {
6317 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6318 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6319 short_channel_id: 4,
6322 cltv_expiry_delta: (4 << 4) | 0,
6323 htlc_minimum_msat: 0,
6324 htlc_maximum_msat: MAX_VALUE_MSAT,
6326 fee_proportional_millionths: 0,
6327 excess_data: Vec::new()
6330 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
6332 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
6333 for (key, flags) in [(&privkeys[3], 0), (&privkeys[2], 3)] {
6334 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6335 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6336 short_channel_id: 3,
6339 cltv_expiry_delta: (3 << 4) | 0,
6340 htlc_minimum_msat: 0,
6341 htlc_maximum_msat: MAX_VALUE_MSAT,
6343 fee_proportional_millionths: 0,
6344 excess_data: Vec::new()
6347 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
6349 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
6350 for (key, flags) in [(&privkeys[2], 0), (&privkeys[4], 3)] {
6351 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6352 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6353 short_channel_id: 2,
6356 cltv_expiry_delta: (2 << 4) | 0,
6357 htlc_minimum_msat: 0,
6358 htlc_maximum_msat: MAX_VALUE_MSAT,
6360 fee_proportional_millionths: 0,
6361 excess_data: Vec::new()
6365 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
6366 for (key, flags) in [(&privkeys[4], 0), (&privkeys[6], 3)] {
6367 update_channel(&gossip_sync, &secp_ctx, key, UnsignedChannelUpdate {
6368 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6369 short_channel_id: 1,
6372 cltv_expiry_delta: (1 << 4) | 0,
6373 htlc_minimum_msat: 100,
6374 htlc_maximum_msat: MAX_VALUE_MSAT,
6376 fee_proportional_millionths: 0,
6377 excess_data: Vec::new()
6380 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
6383 // Now ensure the route flows simply over nodes 1 and 4 to 6.
6384 let route_params = RouteParameters::from_payment_params_and_value(
6385 payment_params, 10_000);
6386 let route = get_route(&our_id, &route_params, &network.read_only(), None,
6387 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6388 assert_eq!(route.paths.len(), 1);
6389 assert_eq!(route.paths[0].hops.len(), 3);
6391 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
6392 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
6393 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
6394 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (5 << 4) | 0);
6395 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(1));
6396 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(6));
6398 assert_eq!(route.paths[0].hops[1].pubkey, nodes[4]);
6399 assert_eq!(route.paths[0].hops[1].short_channel_id, 5);
6400 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
6401 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (1 << 4) | 0);
6402 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(4));
6403 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(5));
6405 assert_eq!(route.paths[0].hops[2].pubkey, nodes[6]);
6406 assert_eq!(route.paths[0].hops[2].short_channel_id, 1);
6407 assert_eq!(route.paths[0].hops[2].fee_msat, 10_000);
6408 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
6409 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
6410 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(1));
6416 fn exact_fee_liquidity_limit() {
6417 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
6418 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
6419 // we calculated fees on a higher value, resulting in us ignoring such paths.
6420 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
6421 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
6422 let scorer = ln_test_utils::TestScorer::new();
6423 let random_seed_bytes = [42; 32];
6424 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
6426 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
6428 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6429 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6430 short_channel_id: 2,
6433 cltv_expiry_delta: 0,
6434 htlc_minimum_msat: 0,
6435 htlc_maximum_msat: 85_000,
6437 fee_proportional_millionths: 0,
6438 excess_data: Vec::new()
6441 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6442 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6443 short_channel_id: 12,
6446 cltv_expiry_delta: (4 << 4) | 1,
6447 htlc_minimum_msat: 0,
6448 htlc_maximum_msat: 270_000,
6450 fee_proportional_millionths: 1000000,
6451 excess_data: Vec::new()
6455 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
6456 // 200% fee charged channel 13 in the 1-to-2 direction.
6457 let mut route_params = RouteParameters::from_payment_params_and_value(
6458 payment_params, 90_000);
6459 route_params.max_total_routing_fee_msat = Some(90_000*2);
6460 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6461 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6462 assert_eq!(route.paths.len(), 1);
6463 assert_eq!(route.paths[0].hops.len(), 2);
6465 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
6466 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
6467 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
6468 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
6469 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
6470 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
6472 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
6473 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
6474 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
6475 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
6476 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
6477 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
6482 fn htlc_max_reduction_below_min() {
6483 // Test that if, while walking the graph, we reduce the value being sent to meet an
6484 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
6485 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
6486 // resulting in us thinking there is no possible path, even if other paths exist.
6487 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
6488 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
6489 let scorer = ln_test_utils::TestScorer::new();
6490 let random_seed_bytes = [42; 32];
6491 let config = UserConfig::default();
6492 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
6493 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
6496 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
6497 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
6498 // then try to send 90_000.
6499 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
6500 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6501 short_channel_id: 2,
6504 cltv_expiry_delta: 0,
6505 htlc_minimum_msat: 0,
6506 htlc_maximum_msat: 80_000,
6508 fee_proportional_millionths: 0,
6509 excess_data: Vec::new()
6511 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
6512 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
6513 short_channel_id: 4,
6516 cltv_expiry_delta: (4 << 4) | 1,
6517 htlc_minimum_msat: 90_000,
6518 htlc_maximum_msat: MAX_VALUE_MSAT,
6520 fee_proportional_millionths: 0,
6521 excess_data: Vec::new()
6525 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
6526 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
6527 // expensive) channels 12-13 path.
6528 let mut route_params = RouteParameters::from_payment_params_and_value(
6529 payment_params, 90_000);
6530 route_params.max_total_routing_fee_msat = Some(90_000*2);
6531 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6532 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6533 assert_eq!(route.paths.len(), 1);
6534 assert_eq!(route.paths[0].hops.len(), 2);
6536 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
6537 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
6538 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
6539 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
6540 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
6541 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
6543 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
6544 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
6545 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
6546 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
6547 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), channelmanager::provided_bolt11_invoice_features(&config).le_flags());
6548 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
6553 fn multiple_direct_first_hops() {
6554 // Previously we'd only ever considered one first hop path per counterparty.
6555 // However, as we don't restrict users to one channel per peer, we really need to support
6556 // looking at all first hop paths.
6557 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
6558 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
6559 // route over multiple channels with the same first hop.
6560 let secp_ctx = Secp256k1::new();
6561 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6562 let logger = Arc::new(ln_test_utils::TestLogger::new());
6563 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
6564 let scorer = ln_test_utils::TestScorer::new();
6565 let config = UserConfig::default();
6566 let payment_params = PaymentParameters::from_node_id(nodes[0], 42)
6567 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
6569 let random_seed_bytes = [42; 32];
6572 let route_params = RouteParameters::from_payment_params_and_value(
6573 payment_params.clone(), 100_000);
6574 let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
6575 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
6576 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
6577 ]), Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6578 assert_eq!(route.paths.len(), 1);
6579 assert_eq!(route.paths[0].hops.len(), 1);
6581 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
6582 assert_eq!(route.paths[0].hops[0].short_channel_id, 3);
6583 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
6586 let route_params = RouteParameters::from_payment_params_and_value(
6587 payment_params.clone(), 100_000);
6588 let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
6589 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6590 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6591 ]), Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6592 assert_eq!(route.paths.len(), 2);
6593 assert_eq!(route.paths[0].hops.len(), 1);
6594 assert_eq!(route.paths[1].hops.len(), 1);
6596 assert!((route.paths[0].hops[0].short_channel_id == 3 && route.paths[1].hops[0].short_channel_id == 2) ||
6597 (route.paths[0].hops[0].short_channel_id == 2 && route.paths[1].hops[0].short_channel_id == 3));
6599 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
6600 assert_eq!(route.paths[0].hops[0].fee_msat, 50_000);
6602 assert_eq!(route.paths[1].hops[0].pubkey, nodes[0]);
6603 assert_eq!(route.paths[1].hops[0].fee_msat, 50_000);
6607 // If we have a bunch of outbound channels to the same node, where most are not
6608 // sufficient to pay the full payment, but one is, we should default to just using the
6609 // one single channel that has sufficient balance, avoiding MPP.
6611 // If we have several options above the 3xpayment value threshold, we should pick the
6612 // smallest of them, avoiding further fragmenting our available outbound balance to
6614 let route_params = RouteParameters::from_payment_params_and_value(
6615 payment_params, 100_000);
6616 let route = get_route(&our_id, &route_params, &network_graph.read_only(), Some(&[
6617 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6618 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6619 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6620 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
6621 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6622 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6623 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
6624 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
6625 ]), Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6626 assert_eq!(route.paths.len(), 1);
6627 assert_eq!(route.paths[0].hops.len(), 1);
6629 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
6630 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
6631 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
6636 fn prefers_shorter_route_with_higher_fees() {
6637 let (secp_ctx, network_graph, _, _, logger) = build_graph();
6638 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6639 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
6641 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
6642 let scorer = ln_test_utils::TestScorer::new();
6643 let random_seed_bytes = [42; 32];
6644 let route_params = RouteParameters::from_payment_params_and_value(
6645 payment_params.clone(), 100);
6646 let route = get_route( &our_id, &route_params, &network_graph.read_only(), None,
6647 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6648 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6650 assert_eq!(route.get_total_fees(), 100);
6651 assert_eq!(route.get_total_amount(), 100);
6652 assert_eq!(path, vec![2, 4, 6, 11, 8]);
6654 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
6655 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
6656 let scorer = FixedPenaltyScorer::with_penalty(100);
6657 let route_params = RouteParameters::from_payment_params_and_value(
6658 payment_params, 100);
6659 let route = get_route( &our_id, &route_params, &network_graph.read_only(), None,
6660 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6661 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6663 assert_eq!(route.get_total_fees(), 300);
6664 assert_eq!(route.get_total_amount(), 100);
6665 assert_eq!(path, vec![2, 4, 7, 10]);
6668 struct BadChannelScorer {
6669 short_channel_id: u64,
6673 impl Writeable for BadChannelScorer {
6674 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
6676 impl ScoreLookUp for BadChannelScorer {
6677 type ScoreParams = ();
6678 fn channel_penalty_msat(&self, candidate: &CandidateRouteHop, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
6679 if candidate.short_channel_id() == Some(self.short_channel_id) { u64::max_value() } else { 0 }
6683 struct BadNodeScorer {
6688 impl Writeable for BadNodeScorer {
6689 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
6692 impl ScoreLookUp for BadNodeScorer {
6693 type ScoreParams = ();
6694 fn channel_penalty_msat(&self, candidate: &CandidateRouteHop, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
6695 if candidate.target() == Some(self.node_id) { u64::max_value() } else { 0 }
6700 fn avoids_routing_through_bad_channels_and_nodes() {
6701 let (secp_ctx, network, _, _, logger) = build_graph();
6702 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6703 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
6704 let network_graph = network.read_only();
6706 // A path to nodes[6] exists when no penalties are applied to any channel.
6707 let scorer = ln_test_utils::TestScorer::new();
6708 let random_seed_bytes = [42; 32];
6709 let route_params = RouteParameters::from_payment_params_and_value(
6710 payment_params, 100);
6711 let route = get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6712 &scorer, &Default::default(), &random_seed_bytes).unwrap();
6713 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6715 assert_eq!(route.get_total_fees(), 100);
6716 assert_eq!(route.get_total_amount(), 100);
6717 assert_eq!(path, vec![2, 4, 6, 11, 8]);
6719 // A different path to nodes[6] exists if channel 6 cannot be routed over.
6720 let scorer = BadChannelScorer { short_channel_id: 6 };
6721 let route = get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6722 &scorer, &Default::default(), &random_seed_bytes).unwrap();
6723 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6725 assert_eq!(route.get_total_fees(), 300);
6726 assert_eq!(route.get_total_amount(), 100);
6727 assert_eq!(path, vec![2, 4, 7, 10]);
6729 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
6730 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
6731 match get_route( &our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6732 &scorer, &Default::default(), &random_seed_bytes) {
6733 Err(LightningError { err, .. } ) => {
6734 assert_eq!(err, "Failed to find a path to the given destination");
6736 Ok(_) => panic!("Expected error"),
6741 fn total_fees_single_path() {
6743 paths: vec![Path { hops: vec![
6745 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
6746 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6747 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0, maybe_announced_channel: true,
6750 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
6751 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6752 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0, maybe_announced_channel: true,
6755 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
6756 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6757 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0, maybe_announced_channel: true,
6759 ], blinded_tail: None }],
6763 assert_eq!(route.get_total_fees(), 250);
6764 assert_eq!(route.get_total_amount(), 225);
6768 fn total_fees_multi_path() {
6770 paths: vec![Path { hops: vec![
6772 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
6773 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6774 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0, maybe_announced_channel: true,
6777 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
6778 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6779 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0, maybe_announced_channel: true,
6781 ], blinded_tail: None }, Path { hops: vec![
6783 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
6784 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6785 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0, maybe_announced_channel: true,
6788 pubkey: PublicKey::from_slice(&<Vec<u8>>::from_hex("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
6789 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
6790 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0, maybe_announced_channel: true,
6792 ], blinded_tail: None }],
6796 assert_eq!(route.get_total_fees(), 200);
6797 assert_eq!(route.get_total_amount(), 300);
6801 fn total_empty_route_no_panic() {
6802 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
6803 // would both panic if the route was completely empty. We test to ensure they return 0
6804 // here, even though its somewhat nonsensical as a route.
6805 let route = Route { paths: Vec::new(), route_params: None };
6807 assert_eq!(route.get_total_fees(), 0);
6808 assert_eq!(route.get_total_amount(), 0);
6812 fn limits_total_cltv_delta() {
6813 let (secp_ctx, network, _, _, logger) = build_graph();
6814 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6815 let network_graph = network.read_only();
6817 let scorer = ln_test_utils::TestScorer::new();
6819 // Make sure that generally there is at least one route available
6820 let feasible_max_total_cltv_delta = 1008;
6821 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
6822 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
6823 let random_seed_bytes = [42; 32];
6824 let route_params = RouteParameters::from_payment_params_and_value(
6825 feasible_payment_params, 100);
6826 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6827 &scorer, &Default::default(), &random_seed_bytes).unwrap();
6828 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6829 assert_ne!(path.len(), 0);
6831 // But not if we exclude all paths on the basis of their accumulated CLTV delta
6832 let fail_max_total_cltv_delta = 23;
6833 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
6834 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
6835 let route_params = RouteParameters::from_payment_params_and_value(
6836 fail_payment_params, 100);
6837 match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
6838 &Default::default(), &random_seed_bytes)
6840 Err(LightningError { err, .. } ) => {
6841 assert_eq!(err, "Failed to find a path to the given destination");
6843 Ok(_) => panic!("Expected error"),
6848 fn avoids_recently_failed_paths() {
6849 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
6850 // randomly inserting channels into it until we can't find a route anymore.
6851 let (secp_ctx, network, _, _, logger) = build_graph();
6852 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6853 let network_graph = network.read_only();
6855 let scorer = ln_test_utils::TestScorer::new();
6856 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
6857 .with_max_path_count(1);
6858 let random_seed_bytes = [42; 32];
6860 // We should be able to find a route initially, and then after we fail a few random
6861 // channels eventually we won't be able to any longer.
6862 let route_params = RouteParameters::from_payment_params_and_value(
6863 payment_params.clone(), 100);
6864 assert!(get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6865 &scorer, &Default::default(), &random_seed_bytes).is_ok());
6867 let route_params = RouteParameters::from_payment_params_and_value(
6868 payment_params.clone(), 100);
6869 if let Ok(route) = get_route(&our_id, &route_params, &network_graph, None,
6870 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes)
6872 for chan in route.paths[0].hops.iter() {
6873 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
6875 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
6876 % route.paths[0].hops.len();
6877 payment_params.previously_failed_channels.push(route.paths[0].hops[victim].short_channel_id);
6883 fn limits_path_length() {
6884 let (secp_ctx, network, _, _, logger) = build_line_graph();
6885 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6886 let network_graph = network.read_only();
6888 let scorer = ln_test_utils::TestScorer::new();
6889 let random_seed_bytes = [42; 32];
6891 // First check we can actually create a long route on this graph.
6892 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
6893 let route_params = RouteParameters::from_payment_params_and_value(
6894 feasible_payment_params, 100);
6895 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
6896 &scorer, &Default::default(), &random_seed_bytes).unwrap();
6897 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
6898 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
6900 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
6901 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
6902 let route_params = RouteParameters::from_payment_params_and_value(
6903 fail_payment_params, 100);
6904 match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
6905 &Default::default(), &random_seed_bytes)
6907 Err(LightningError { err, .. } ) => {
6908 assert_eq!(err, "Failed to find a path to the given destination");
6910 Ok(_) => panic!("Expected error"),
6915 fn adds_and_limits_cltv_offset() {
6916 let (secp_ctx, network_graph, _, _, logger) = build_graph();
6917 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6919 let scorer = ln_test_utils::TestScorer::new();
6921 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
6922 let random_seed_bytes = [42; 32];
6923 let route_params = RouteParameters::from_payment_params_and_value(
6924 payment_params.clone(), 100);
6925 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
6926 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6927 assert_eq!(route.paths.len(), 1);
6929 let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
6931 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
6932 let mut route_default = route.clone();
6933 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
6934 let cltv_expiry_deltas_default = route_default.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
6935 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
6936 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
6937 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
6939 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
6940 let mut route_limited = route.clone();
6941 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
6942 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
6943 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
6944 let cltv_expiry_deltas_limited = route_limited.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
6945 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
6949 fn adds_plausible_cltv_offset() {
6950 let (secp_ctx, network, _, _, logger) = build_graph();
6951 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6952 let network_graph = network.read_only();
6953 let network_nodes = network_graph.nodes();
6954 let network_channels = network_graph.channels();
6955 let scorer = ln_test_utils::TestScorer::new();
6956 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
6957 let random_seed_bytes = [42; 32];
6959 let route_params = RouteParameters::from_payment_params_and_value(
6960 payment_params.clone(), 100);
6961 let mut route = get_route(&our_id, &route_params, &network_graph, None,
6962 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes).unwrap();
6963 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
6965 let mut path_plausibility = vec![];
6967 for p in route.paths {
6968 // 1. Select random observation point
6969 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
6970 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
6972 prng.process_in_place(&mut random_bytes);
6973 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.hops.len());
6974 let observation_point = NodeId::from_pubkey(&p.hops.get(random_path_index).unwrap().pubkey);
6976 // 2. Calculate what CLTV expiry delta we would observe there
6977 let observed_cltv_expiry_delta: u32 = p.hops[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
6979 // 3. Starting from the observation point, find candidate paths
6980 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
6981 candidates.push_back((observation_point, vec![]));
6983 let mut found_plausible_candidate = false;
6985 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
6986 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
6987 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
6988 found_plausible_candidate = true;
6989 break 'candidate_loop;
6993 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
6994 for channel_id in &cur_node.channels {
6995 if let Some(channel_info) = network_channels.get(&channel_id) {
6996 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
6997 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
6998 if cur_path_cltv_deltas.iter().sum::<u32>()
6999 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
7000 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
7001 new_path_cltv_deltas.push(next_cltv_expiry_delta);
7002 candidates.push_back((*next_id, new_path_cltv_deltas));
7010 path_plausibility.push(found_plausible_candidate);
7012 assert!(path_plausibility.iter().all(|x| *x));
7016 fn builds_correct_path_from_hops() {
7017 let (secp_ctx, network, _, _, logger) = build_graph();
7018 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7019 let network_graph = network.read_only();
7021 let random_seed_bytes = [42; 32];
7022 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
7023 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
7024 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 100);
7025 let route = build_route_from_hops_internal(&our_id, &hops, &route_params, &network_graph,
7026 Arc::clone(&logger), &random_seed_bytes).unwrap();
7027 let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
7028 assert_eq!(hops.len(), route.paths[0].hops.len());
7029 for (idx, hop_pubkey) in hops.iter().enumerate() {
7030 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
7035 fn avoids_saturating_channels() {
7036 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
7037 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
7038 let decay_params = ProbabilisticScoringDecayParameters::default();
7039 let scorer = ProbabilisticScorer::new(decay_params, &*network_graph, Arc::clone(&logger));
7041 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
7042 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
7043 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
7044 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
7045 short_channel_id: 4,
7048 cltv_expiry_delta: (4 << 4) | 1,
7049 htlc_minimum_msat: 0,
7050 htlc_maximum_msat: 250_000_000,
7052 fee_proportional_millionths: 0,
7053 excess_data: Vec::new()
7055 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
7056 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
7057 short_channel_id: 13,
7060 cltv_expiry_delta: (13 << 4) | 1,
7061 htlc_minimum_msat: 0,
7062 htlc_maximum_msat: 250_000_000,
7064 fee_proportional_millionths: 0,
7065 excess_data: Vec::new()
7068 let config = UserConfig::default();
7069 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
7070 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
7072 let random_seed_bytes = [42; 32];
7074 // 100,000 sats is less than the available liquidity on each channel, set above.
7075 let route_params = RouteParameters::from_payment_params_and_value(
7076 payment_params, 100_000_000);
7077 let route = get_route(&our_id, &route_params, &network_graph.read_only(), None,
7078 Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(), &random_seed_bytes).unwrap();
7079 assert_eq!(route.paths.len(), 2);
7080 assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
7081 (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
7084 #[cfg(feature = "std")]
7085 pub(super) fn random_init_seed() -> u64 {
7086 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
7087 use core::hash::{BuildHasher, Hasher};
7088 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
7089 println!("Using seed of {}", seed);
7094 #[cfg(feature = "std")]
7095 fn generate_routes() {
7096 use crate::routing::scoring::ProbabilisticScoringFeeParameters;
7098 let logger = ln_test_utils::TestLogger::new();
7099 let (graph, mut scorer) = match super::bench_utils::read_graph_scorer(&logger) {
7107 let params = ProbabilisticScoringFeeParameters::default();
7108 let features = super::Bolt11InvoiceFeatures::empty();
7110 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
7114 #[cfg(feature = "std")]
7115 fn generate_routes_mpp() {
7116 use crate::routing::scoring::ProbabilisticScoringFeeParameters;
7118 let logger = ln_test_utils::TestLogger::new();
7119 let (graph, mut scorer) = match super::bench_utils::read_graph_scorer(&logger) {
7127 let params = ProbabilisticScoringFeeParameters::default();
7128 let features = channelmanager::provided_bolt11_invoice_features(&UserConfig::default());
7130 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
7134 #[cfg(feature = "std")]
7135 fn generate_large_mpp_routes() {
7136 use crate::routing::scoring::ProbabilisticScoringFeeParameters;
7138 let logger = ln_test_utils::TestLogger::new();
7139 let (graph, mut scorer) = match super::bench_utils::read_graph_scorer(&logger) {
7147 let params = ProbabilisticScoringFeeParameters::default();
7148 let features = channelmanager::provided_bolt11_invoice_features(&UserConfig::default());
7150 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 1_000_000, 2);
7154 fn honors_manual_penalties() {
7155 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
7156 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7158 let random_seed_bytes = [42; 32];
7159 let mut scorer_params = ProbabilisticScoringFeeParameters::default();
7160 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), Arc::clone(&network_graph), Arc::clone(&logger));
7162 // First check set manual penalties are returned by the scorer.
7163 let usage = ChannelUsage {
7165 inflight_htlc_msat: 0,
7166 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
7168 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
7169 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
7170 let network_graph = network_graph.read_only();
7171 let channels = network_graph.channels();
7172 let channel = channels.get(&5).unwrap();
7173 let info = channel.as_directed_from(&NodeId::from_pubkey(&nodes[3])).unwrap();
7174 let candidate: CandidateRouteHop = CandidateRouteHop::PublicHop(PublicHopCandidate {
7176 short_channel_id: 5,
7178 assert_eq!(scorer.channel_penalty_msat(&candidate, usage, &scorer_params), 456);
7180 // Then check we can get a normal route
7181 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
7182 let route_params = RouteParameters::from_payment_params_and_value(
7183 payment_params, 100);
7184 let route = get_route(&our_id, &route_params, &network_graph, None,
7185 Arc::clone(&logger), &scorer, &scorer_params, &random_seed_bytes);
7186 assert!(route.is_ok());
7188 // Then check that we can't get a route if we ban an intermediate node.
7189 scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3]));
7190 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
7191 assert!(route.is_err());
7193 // Finally make sure we can route again, when we remove the ban.
7194 scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3]));
7195 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
7196 assert!(route.is_ok());
7200 fn abide_by_route_hint_max_htlc() {
7201 // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
7202 // params in the final route.
7203 let (secp_ctx, network_graph, _, _, logger) = build_graph();
7204 let netgraph = network_graph.read_only();
7205 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7206 let scorer = ln_test_utils::TestScorer::new();
7207 let random_seed_bytes = [42; 32];
7208 let config = UserConfig::default();
7210 let max_htlc_msat = 50_000;
7211 let route_hint_1 = RouteHint(vec![RouteHintHop {
7212 src_node_id: nodes[2],
7213 short_channel_id: 42,
7216 proportional_millionths: 0,
7218 cltv_expiry_delta: 10,
7219 htlc_minimum_msat: None,
7220 htlc_maximum_msat: Some(max_htlc_msat),
7222 let dest_node_id = ln_test_utils::pubkey(42);
7223 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
7224 .with_route_hints(vec![route_hint_1.clone()]).unwrap()
7225 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
7228 // Make sure we'll error if our route hints don't have enough liquidity according to their
7229 // htlc_maximum_msat.
7230 let mut route_params = RouteParameters::from_payment_params_and_value(
7231 payment_params, max_htlc_msat + 1);
7232 route_params.max_total_routing_fee_msat = None;
7233 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
7234 &route_params, &netgraph, None, Arc::clone(&logger), &scorer, &Default::default(),
7237 assert_eq!(err, "Failed to find a sufficient route to the given destination");
7238 } else { panic!(); }
7240 // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
7241 let mut route_hint_2 = route_hint_1.clone();
7242 route_hint_2.0[0].short_channel_id = 43;
7243 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
7244 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
7245 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
7247 let mut route_params = RouteParameters::from_payment_params_and_value(
7248 payment_params, max_htlc_msat + 1);
7249 route_params.max_total_routing_fee_msat = Some(max_htlc_msat * 2);
7250 let route = get_route(&our_id, &route_params, &netgraph, None, Arc::clone(&logger),
7251 &scorer, &Default::default(), &random_seed_bytes).unwrap();
7252 assert_eq!(route.paths.len(), 2);
7253 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
7254 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
7258 fn direct_channel_to_hints_with_max_htlc() {
7259 // Check that if we have a first hop channel peer that's connected to multiple provided route
7260 // hints, that we properly split the payment between the route hints if needed.
7261 let logger = Arc::new(ln_test_utils::TestLogger::new());
7262 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
7263 let scorer = ln_test_utils::TestScorer::new();
7264 let random_seed_bytes = [42; 32];
7265 let config = UserConfig::default();
7267 let our_node_id = ln_test_utils::pubkey(42);
7268 let intermed_node_id = ln_test_utils::pubkey(43);
7269 let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
7271 let amt_msat = 900_000;
7272 let max_htlc_msat = 500_000;
7273 let route_hint_1 = RouteHint(vec![RouteHintHop {
7274 src_node_id: intermed_node_id,
7275 short_channel_id: 44,
7278 proportional_millionths: 0,
7280 cltv_expiry_delta: 10,
7281 htlc_minimum_msat: None,
7282 htlc_maximum_msat: Some(max_htlc_msat),
7284 src_node_id: intermed_node_id,
7285 short_channel_id: 45,
7288 proportional_millionths: 0,
7290 cltv_expiry_delta: 10,
7291 htlc_minimum_msat: None,
7292 // Check that later route hint max htlcs don't override earlier ones
7293 htlc_maximum_msat: Some(max_htlc_msat - 50),
7295 let mut route_hint_2 = route_hint_1.clone();
7296 route_hint_2.0[0].short_channel_id = 46;
7297 route_hint_2.0[1].short_channel_id = 47;
7298 let dest_node_id = ln_test_utils::pubkey(44);
7299 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
7300 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
7301 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config))
7304 let route_params = RouteParameters::from_payment_params_and_value(
7305 payment_params, amt_msat);
7306 let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
7307 Some(&first_hop.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7308 &Default::default(), &random_seed_bytes).unwrap();
7309 assert_eq!(route.paths.len(), 2);
7310 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
7311 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
7312 assert_eq!(route.get_total_amount(), amt_msat);
7314 // Re-run but with two first hop channels connected to the same route hint peers that must be
7316 let first_hops = vec![
7317 get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
7318 get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
7320 let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
7321 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7322 &Default::default(), &random_seed_bytes).unwrap();
7323 assert_eq!(route.paths.len(), 2);
7324 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
7325 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
7326 assert_eq!(route.get_total_amount(), amt_msat);
7328 // Make sure this works for blinded route hints.
7329 let blinded_path = BlindedPath {
7330 introduction_node: IntroductionNode::NodeId(intermed_node_id),
7331 blinding_point: ln_test_utils::pubkey(42),
7333 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42), encrypted_payload: vec![] },
7334 BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![] },
7337 let blinded_payinfo = BlindedPayInfo {
7339 fee_proportional_millionths: 0,
7340 htlc_minimum_msat: 1,
7341 htlc_maximum_msat: max_htlc_msat,
7342 cltv_expiry_delta: 10,
7343 features: BlindedHopFeatures::empty(),
7345 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
7346 let payment_params = PaymentParameters::blinded(vec![
7347 (blinded_payinfo.clone(), blinded_path.clone()),
7348 (blinded_payinfo.clone(), blinded_path.clone())])
7349 .with_bolt12_features(bolt12_features).unwrap();
7350 let route_params = RouteParameters::from_payment_params_and_value(
7351 payment_params, amt_msat);
7352 let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
7353 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7354 &Default::default(), &random_seed_bytes).unwrap();
7355 assert_eq!(route.paths.len(), 2);
7356 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
7357 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
7358 assert_eq!(route.get_total_amount(), amt_msat);
7362 fn blinded_route_ser() {
7363 let blinded_path_1 = BlindedPath {
7364 introduction_node: IntroductionNode::NodeId(ln_test_utils::pubkey(42)),
7365 blinding_point: ln_test_utils::pubkey(43),
7367 BlindedHop { blinded_node_id: ln_test_utils::pubkey(44), encrypted_payload: Vec::new() },
7368 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() }
7371 let blinded_path_2 = BlindedPath {
7372 introduction_node: IntroductionNode::NodeId(ln_test_utils::pubkey(46)),
7373 blinding_point: ln_test_utils::pubkey(47),
7375 BlindedHop { blinded_node_id: ln_test_utils::pubkey(48), encrypted_payload: Vec::new() },
7376 BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }
7379 // (De)serialize a Route with 1 blinded path out of two total paths.
7380 let mut route = Route { paths: vec![Path {
7381 hops: vec![RouteHop {
7382 pubkey: ln_test_utils::pubkey(50),
7383 node_features: NodeFeatures::empty(),
7384 short_channel_id: 42,
7385 channel_features: ChannelFeatures::empty(),
7387 cltv_expiry_delta: 0,
7388 maybe_announced_channel: true,
7390 blinded_tail: Some(BlindedTail {
7391 hops: blinded_path_1.blinded_hops,
7392 blinding_point: blinded_path_1.blinding_point,
7393 excess_final_cltv_expiry_delta: 40,
7394 final_value_msat: 100,
7396 hops: vec![RouteHop {
7397 pubkey: ln_test_utils::pubkey(51),
7398 node_features: NodeFeatures::empty(),
7399 short_channel_id: 43,
7400 channel_features: ChannelFeatures::empty(),
7402 cltv_expiry_delta: 0,
7403 maybe_announced_channel: true,
7404 }], blinded_tail: None }],
7407 let encoded_route = route.encode();
7408 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
7409 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
7410 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
7412 // (De)serialize a Route with two paths, each containing a blinded tail.
7413 route.paths[1].blinded_tail = Some(BlindedTail {
7414 hops: blinded_path_2.blinded_hops,
7415 blinding_point: blinded_path_2.blinding_point,
7416 excess_final_cltv_expiry_delta: 41,
7417 final_value_msat: 101,
7419 let encoded_route = route.encode();
7420 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
7421 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
7422 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
7426 fn blinded_path_inflight_processing() {
7427 // Ensure we'll score the channel that's inbound to a blinded path's introduction node, and
7428 // account for the blinded tail's final amount_msat.
7429 let mut inflight_htlcs = InFlightHtlcs::new();
7430 let blinded_path = BlindedPath {
7431 introduction_node: IntroductionNode::NodeId(ln_test_utils::pubkey(43)),
7432 blinding_point: ln_test_utils::pubkey(48),
7433 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }],
7436 hops: vec![RouteHop {
7437 pubkey: ln_test_utils::pubkey(42),
7438 node_features: NodeFeatures::empty(),
7439 short_channel_id: 42,
7440 channel_features: ChannelFeatures::empty(),
7442 cltv_expiry_delta: 0,
7443 maybe_announced_channel: false,
7446 pubkey: ln_test_utils::pubkey(43),
7447 node_features: NodeFeatures::empty(),
7448 short_channel_id: 43,
7449 channel_features: ChannelFeatures::empty(),
7451 cltv_expiry_delta: 0,
7452 maybe_announced_channel: false,
7454 blinded_tail: Some(BlindedTail {
7455 hops: blinded_path.blinded_hops,
7456 blinding_point: blinded_path.blinding_point,
7457 excess_final_cltv_expiry_delta: 0,
7458 final_value_msat: 200,
7461 inflight_htlcs.process_path(&path, ln_test_utils::pubkey(44));
7462 assert_eq!(*inflight_htlcs.0.get(&(42, true)).unwrap(), 301);
7463 assert_eq!(*inflight_htlcs.0.get(&(43, false)).unwrap(), 201);
7467 fn blinded_path_cltv_shadow_offset() {
7468 // Make sure we add a shadow offset when sending to blinded paths.
7469 let blinded_path = BlindedPath {
7470 introduction_node: IntroductionNode::NodeId(ln_test_utils::pubkey(43)),
7471 blinding_point: ln_test_utils::pubkey(44),
7473 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() },
7474 BlindedHop { blinded_node_id: ln_test_utils::pubkey(46), encrypted_payload: Vec::new() }
7477 let mut route = Route { paths: vec![Path {
7478 hops: vec![RouteHop {
7479 pubkey: ln_test_utils::pubkey(42),
7480 node_features: NodeFeatures::empty(),
7481 short_channel_id: 42,
7482 channel_features: ChannelFeatures::empty(),
7484 cltv_expiry_delta: 0,
7485 maybe_announced_channel: false,
7488 pubkey: ln_test_utils::pubkey(43),
7489 node_features: NodeFeatures::empty(),
7490 short_channel_id: 43,
7491 channel_features: ChannelFeatures::empty(),
7493 cltv_expiry_delta: 0,
7494 maybe_announced_channel: false,
7497 blinded_tail: Some(BlindedTail {
7498 hops: blinded_path.blinded_hops,
7499 blinding_point: blinded_path.blinding_point,
7500 excess_final_cltv_expiry_delta: 0,
7501 final_value_msat: 200,
7503 }], route_params: None};
7505 let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
7506 let (_, network_graph, _, _, _) = build_line_graph();
7507 add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
7508 assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
7509 assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
7513 fn simple_blinded_route_hints() {
7514 do_simple_blinded_route_hints(1);
7515 do_simple_blinded_route_hints(2);
7516 do_simple_blinded_route_hints(3);
7519 fn do_simple_blinded_route_hints(num_blinded_hops: usize) {
7520 // Check that we can generate a route to a blinded path with the expected hops.
7521 let (secp_ctx, network, _, _, logger) = build_graph();
7522 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7523 let network_graph = network.read_only();
7525 let scorer = ln_test_utils::TestScorer::new();
7526 let random_seed_bytes = [42; 32];
7528 let mut blinded_path = BlindedPath {
7529 introduction_node: IntroductionNode::NodeId(nodes[2]),
7530 blinding_point: ln_test_utils::pubkey(42),
7531 blinded_hops: Vec::with_capacity(num_blinded_hops),
7533 for i in 0..num_blinded_hops {
7534 blinded_path.blinded_hops.push(
7535 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 + i as u8), encrypted_payload: Vec::new() },
7538 let blinded_payinfo = BlindedPayInfo {
7540 fee_proportional_millionths: 500,
7541 htlc_minimum_msat: 1000,
7542 htlc_maximum_msat: 100_000_000,
7543 cltv_expiry_delta: 15,
7544 features: BlindedHopFeatures::empty(),
7547 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())]);
7548 let route_params = RouteParameters::from_payment_params_and_value(
7549 payment_params, 1001);
7550 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
7551 &scorer, &Default::default(), &random_seed_bytes).unwrap();
7552 assert_eq!(route.paths.len(), 1);
7553 assert_eq!(route.paths[0].hops.len(), 2);
7555 let tail = route.paths[0].blinded_tail.as_ref().unwrap();
7556 assert_eq!(tail.hops, blinded_path.blinded_hops);
7557 assert_eq!(tail.excess_final_cltv_expiry_delta, 0);
7558 assert_eq!(tail.final_value_msat, 1001);
7560 let final_hop = route.paths[0].hops.last().unwrap();
7562 NodeId::from_pubkey(&final_hop.pubkey),
7563 *blinded_path.public_introduction_node_id(&network_graph).unwrap()
7565 if tail.hops.len() > 1 {
7566 assert_eq!(final_hop.fee_msat,
7567 blinded_payinfo.fee_base_msat as u64 + blinded_payinfo.fee_proportional_millionths as u64 * tail.final_value_msat / 1000000);
7568 assert_eq!(final_hop.cltv_expiry_delta, blinded_payinfo.cltv_expiry_delta as u32);
7570 assert_eq!(final_hop.fee_msat, 0);
7571 assert_eq!(final_hop.cltv_expiry_delta, 0);
7576 fn blinded_path_routing_errors() {
7577 // Check that we can generate a route to a blinded path with the expected hops.
7578 let (secp_ctx, network, _, _, logger) = build_graph();
7579 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7580 let network_graph = network.read_only();
7582 let scorer = ln_test_utils::TestScorer::new();
7583 let random_seed_bytes = [42; 32];
7585 let mut invalid_blinded_path = BlindedPath {
7586 introduction_node: IntroductionNode::NodeId(nodes[2]),
7587 blinding_point: ln_test_utils::pubkey(42),
7589 BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![0; 43] },
7592 let blinded_payinfo = BlindedPayInfo {
7594 fee_proportional_millionths: 500,
7595 htlc_minimum_msat: 1000,
7596 htlc_maximum_msat: 100_000_000,
7597 cltv_expiry_delta: 15,
7598 features: BlindedHopFeatures::empty(),
7601 let mut invalid_blinded_path_2 = invalid_blinded_path.clone();
7602 invalid_blinded_path_2.introduction_node = IntroductionNode::NodeId(ln_test_utils::pubkey(45));
7603 let payment_params = PaymentParameters::blinded(vec![
7604 (blinded_payinfo.clone(), invalid_blinded_path.clone()),
7605 (blinded_payinfo.clone(), invalid_blinded_path_2)]);
7606 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
7607 match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
7608 &scorer, &Default::default(), &random_seed_bytes)
7610 Err(LightningError { err, .. }) => {
7611 assert_eq!(err, "1-hop blinded paths must all have matching introduction node ids");
7613 _ => panic!("Expected error")
7616 invalid_blinded_path.introduction_node = IntroductionNode::NodeId(our_id);
7617 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), invalid_blinded_path.clone())]);
7618 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
7619 match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
7620 &Default::default(), &random_seed_bytes)
7622 Err(LightningError { err, .. }) => {
7623 assert_eq!(err, "Cannot generate a route to blinded paths if we are the introduction node to all of them");
7625 _ => panic!("Expected error")
7628 invalid_blinded_path.introduction_node = IntroductionNode::NodeId(ln_test_utils::pubkey(46));
7629 invalid_blinded_path.blinded_hops.clear();
7630 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo, invalid_blinded_path)]);
7631 let route_params = RouteParameters::from_payment_params_and_value(payment_params, 1001);
7632 match get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger), &scorer,
7633 &Default::default(), &random_seed_bytes)
7635 Err(LightningError { err, .. }) => {
7636 assert_eq!(err, "0-hop blinded path provided");
7638 _ => panic!("Expected error")
7643 fn matching_intro_node_paths_provided() {
7644 // Check that if multiple blinded paths with the same intro node are provided in payment
7645 // parameters, we'll return the correct paths in the resulting MPP route.
7646 let (secp_ctx, network, _, _, logger) = build_graph();
7647 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7648 let network_graph = network.read_only();
7650 let scorer = ln_test_utils::TestScorer::new();
7651 let random_seed_bytes = [42; 32];
7652 let config = UserConfig::default();
7654 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
7655 let blinded_path_1 = BlindedPath {
7656 introduction_node: IntroductionNode::NodeId(nodes[2]),
7657 blinding_point: ln_test_utils::pubkey(42),
7659 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
7660 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
7663 let blinded_payinfo_1 = BlindedPayInfo {
7665 fee_proportional_millionths: 0,
7666 htlc_minimum_msat: 0,
7667 htlc_maximum_msat: 30_000,
7668 cltv_expiry_delta: 0,
7669 features: BlindedHopFeatures::empty(),
7672 let mut blinded_path_2 = blinded_path_1.clone();
7673 blinded_path_2.blinding_point = ln_test_utils::pubkey(43);
7674 let mut blinded_payinfo_2 = blinded_payinfo_1.clone();
7675 blinded_payinfo_2.htlc_maximum_msat = 70_000;
7677 let blinded_hints = vec![
7678 (blinded_payinfo_1.clone(), blinded_path_1.clone()),
7679 (blinded_payinfo_2.clone(), blinded_path_2.clone()),
7681 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
7682 .with_bolt12_features(bolt12_features).unwrap();
7684 let mut route_params = RouteParameters::from_payment_params_and_value(payment_params, 100_000);
7685 route_params.max_total_routing_fee_msat = Some(100_000);
7686 let route = get_route(&our_id, &route_params, &network_graph, None, Arc::clone(&logger),
7687 &scorer, &Default::default(), &random_seed_bytes).unwrap();
7688 assert_eq!(route.paths.len(), 2);
7689 let mut total_amount_paid_msat = 0;
7690 for path in route.paths.into_iter() {
7691 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
7692 if let Some(bt) = &path.blinded_tail {
7693 assert_eq!(bt.blinding_point,
7694 blinded_hints.iter().find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
7695 .map(|(_, bp)| bp.blinding_point).unwrap());
7696 } else { panic!(); }
7697 total_amount_paid_msat += path.final_value_msat();
7699 assert_eq!(total_amount_paid_msat, 100_000);
7703 fn direct_to_intro_node() {
7704 // This previously caused a debug panic in the router when asserting
7705 // `used_liquidity_msat <= hop_max_msat`, because when adding first_hop<>blinded_route_hint
7706 // direct channels we failed to account for the fee charged for use of the blinded path.
7709 // node0 -1(1)2 - node1
7710 // such that there isn't enough liquidity to reach node1, but the router thinks there is if it
7711 // doesn't account for the blinded path fee.
7713 let secp_ctx = Secp256k1::new();
7714 let logger = Arc::new(ln_test_utils::TestLogger::new());
7715 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
7716 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
7717 let scorer = ln_test_utils::TestScorer::new();
7718 let random_seed_bytes = [42; 32];
7720 let amt_msat = 10_000_000;
7721 let (_, _, privkeys, nodes) = get_nodes(&secp_ctx);
7722 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[1],
7723 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
7724 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
7725 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
7726 short_channel_id: 1,
7729 cltv_expiry_delta: 42,
7730 htlc_minimum_msat: 1_000,
7731 htlc_maximum_msat: 10_000_000,
7733 fee_proportional_millionths: 0,
7734 excess_data: Vec::new()
7736 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
7737 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
7738 short_channel_id: 1,
7741 cltv_expiry_delta: 42,
7742 htlc_minimum_msat: 1_000,
7743 htlc_maximum_msat: 10_000_000,
7745 fee_proportional_millionths: 0,
7746 excess_data: Vec::new()
7748 let first_hops = vec![
7749 get_channel_details(Some(1), nodes[1], InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
7751 let blinded_path = BlindedPath {
7752 introduction_node: IntroductionNode::NodeId(nodes[1]),
7753 blinding_point: ln_test_utils::pubkey(42),
7755 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
7756 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
7759 let blinded_payinfo = BlindedPayInfo {
7760 fee_base_msat: 1000,
7761 fee_proportional_millionths: 0,
7762 htlc_minimum_msat: 1000,
7763 htlc_maximum_msat: MAX_VALUE_MSAT,
7764 cltv_expiry_delta: 0,
7765 features: BlindedHopFeatures::empty(),
7767 let blinded_hints = vec![(blinded_payinfo.clone(), blinded_path)];
7769 let payment_params = PaymentParameters::blinded(blinded_hints.clone());
7771 let netgraph = network_graph.read_only();
7772 let route_params = RouteParameters::from_payment_params_and_value(
7773 payment_params.clone(), amt_msat);
7774 if let Err(LightningError { err, .. }) = get_route(&nodes[0], &route_params, &netgraph,
7775 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7776 &Default::default(), &random_seed_bytes) {
7777 assert_eq!(err, "Failed to find a path to the given destination");
7778 } else { panic!("Expected error") }
7780 // Sending an exact amount accounting for the blinded path fee works.
7781 let amt_minus_blinded_path_fee = amt_msat - blinded_payinfo.fee_base_msat as u64;
7782 let route_params = RouteParameters::from_payment_params_and_value(
7783 payment_params, amt_minus_blinded_path_fee);
7784 let route = get_route(&nodes[0], &route_params, &netgraph,
7785 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7786 &Default::default(), &random_seed_bytes).unwrap();
7787 assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
7788 assert_eq!(route.get_total_amount(), amt_minus_blinded_path_fee);
7792 fn direct_to_matching_intro_nodes() {
7793 // This previously caused us to enter `unreachable` code in the following situation:
7794 // 1. We add a route candidate for intro_node contributing a high amount
7795 // 2. We add a first_hop<>intro_node route candidate for the same high amount
7796 // 3. We see a cheaper blinded route hint for the same intro node but a much lower contribution
7797 // amount, and update our route candidate for intro_node for the lower amount
7798 // 4. We then attempt to update the aforementioned first_hop<>intro_node route candidate for the
7799 // lower contribution amount, but fail (this was previously caused by failure to account for
7800 // blinded path fees when adding first_hop<>intro_node candidates)
7801 // 5. We go to construct the path from these route candidates and our first_hop<>intro_node
7802 // candidate still thinks its path is contributing the original higher amount. This caused us
7803 // to hit an `unreachable` overflow when calculating the cheaper intro_node fees over the
7805 let secp_ctx = Secp256k1::new();
7806 let logger = Arc::new(ln_test_utils::TestLogger::new());
7807 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
7808 let scorer = ln_test_utils::TestScorer::new();
7809 let random_seed_bytes = [42; 32];
7810 let config = UserConfig::default();
7812 // Values are taken from the fuzz input that uncovered this panic.
7813 let amt_msat = 21_7020_5185_1403_2640;
7814 let (_, _, _, nodes) = get_nodes(&secp_ctx);
7815 let first_hops = vec![
7816 get_channel_details(Some(1), nodes[1], channelmanager::provided_init_features(&config),
7817 18446744073709551615)];
7819 let blinded_path = BlindedPath {
7820 introduction_node: IntroductionNode::NodeId(nodes[1]),
7821 blinding_point: ln_test_utils::pubkey(42),
7823 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
7824 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
7827 let blinded_payinfo = BlindedPayInfo {
7828 fee_base_msat: 5046_2720,
7829 fee_proportional_millionths: 0,
7830 htlc_minimum_msat: 4503_5996_2737_0496,
7831 htlc_maximum_msat: 45_0359_9627_3704_9600,
7832 cltv_expiry_delta: 0,
7833 features: BlindedHopFeatures::empty(),
7835 let mut blinded_hints = vec![
7836 (blinded_payinfo.clone(), blinded_path.clone()),
7837 (blinded_payinfo.clone(), blinded_path.clone()),
7839 blinded_hints[1].0.fee_base_msat = 419_4304;
7840 blinded_hints[1].0.fee_proportional_millionths = 257;
7841 blinded_hints[1].0.htlc_minimum_msat = 280_8908_6115_8400;
7842 blinded_hints[1].0.htlc_maximum_msat = 2_8089_0861_1584_0000;
7843 blinded_hints[1].0.cltv_expiry_delta = 0;
7845 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
7846 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
7847 .with_bolt12_features(bolt12_features).unwrap();
7849 let netgraph = network_graph.read_only();
7850 let route_params = RouteParameters::from_payment_params_and_value(
7851 payment_params, amt_msat);
7852 let route = get_route(&nodes[0], &route_params, &netgraph,
7853 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
7854 &Default::default(), &random_seed_bytes).unwrap();
7855 assert_eq!(route.get_total_fees(), blinded_payinfo.fee_base_msat as u64);
7856 assert_eq!(route.get_total_amount(), amt_msat);
7860 fn we_are_intro_node_candidate_hops() {
7861 // This previously led to a panic in the router because we'd generate a Path with only a
7862 // BlindedTail and 0 unblinded hops, due to the only candidate hops being blinded route hints
7863 // where the origin node is the intro node. We now fully disallow considering candidate hops
7864 // where the origin node is the intro node.
7865 let (secp_ctx, network_graph, _, _, logger) = build_graph();
7866 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7867 let scorer = ln_test_utils::TestScorer::new();
7868 let random_seed_bytes = [42; 32];
7869 let config = UserConfig::default();
7871 // Values are taken from the fuzz input that uncovered this panic.
7872 let amt_msat = 21_7020_5185_1423_0019;
7874 let blinded_path = BlindedPath {
7875 introduction_node: IntroductionNode::NodeId(our_id),
7876 blinding_point: ln_test_utils::pubkey(42),
7878 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
7879 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
7882 let blinded_payinfo = BlindedPayInfo {
7883 fee_base_msat: 5052_9027,
7884 fee_proportional_millionths: 0,
7885 htlc_minimum_msat: 21_7020_5185_1423_0019,
7886 htlc_maximum_msat: 1844_6744_0737_0955_1615,
7887 cltv_expiry_delta: 0,
7888 features: BlindedHopFeatures::empty(),
7890 let mut blinded_hints = vec![
7891 (blinded_payinfo.clone(), blinded_path.clone()),
7892 (blinded_payinfo.clone(), blinded_path.clone()),
7894 blinded_hints[1].1.introduction_node = IntroductionNode::NodeId(nodes[6]);
7896 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
7897 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
7898 .with_bolt12_features(bolt12_features.clone()).unwrap();
7900 let netgraph = network_graph.read_only();
7901 let route_params = RouteParameters::from_payment_params_and_value(
7902 payment_params, amt_msat);
7903 if let Err(LightningError { err, .. }) = get_route(
7904 &our_id, &route_params, &netgraph, None, Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes
7906 assert_eq!(err, "Failed to find a path to the given destination");
7911 fn we_are_intro_node_bp_in_final_path_fee_calc() {
7912 // This previously led to a debug panic in the router because we'd find an invalid Path with
7913 // 0 unblinded hops and a blinded tail, leading to the generation of a final
7914 // PaymentPathHop::fee_msat that included both the blinded path fees and the final value of
7915 // the payment, when it was intended to only include the final value of the payment.
7916 let (secp_ctx, network_graph, _, _, logger) = build_graph();
7917 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7918 let scorer = ln_test_utils::TestScorer::new();
7919 let random_seed_bytes = [42; 32];
7920 let config = UserConfig::default();
7922 // Values are taken from the fuzz input that uncovered this panic.
7923 let amt_msat = 21_7020_5185_1423_0019;
7925 let blinded_path = BlindedPath {
7926 introduction_node: IntroductionNode::NodeId(our_id),
7927 blinding_point: ln_test_utils::pubkey(42),
7929 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
7930 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
7933 let blinded_payinfo = BlindedPayInfo {
7934 fee_base_msat: 10_4425_1395,
7935 fee_proportional_millionths: 0,
7936 htlc_minimum_msat: 21_7301_9934_9094_0931,
7937 htlc_maximum_msat: 1844_6744_0737_0955_1615,
7938 cltv_expiry_delta: 0,
7939 features: BlindedHopFeatures::empty(),
7941 let mut blinded_hints = vec![
7942 (blinded_payinfo.clone(), blinded_path.clone()),
7943 (blinded_payinfo.clone(), blinded_path.clone()),
7944 (blinded_payinfo.clone(), blinded_path.clone()),
7946 blinded_hints[1].0.fee_base_msat = 5052_9027;
7947 blinded_hints[1].0.htlc_minimum_msat = 21_7020_5185_1423_0019;
7948 blinded_hints[1].0.htlc_maximum_msat = 1844_6744_0737_0955_1615;
7950 blinded_hints[2].1.introduction_node = IntroductionNode::NodeId(nodes[6]);
7952 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
7953 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
7954 .with_bolt12_features(bolt12_features.clone()).unwrap();
7956 let netgraph = network_graph.read_only();
7957 let route_params = RouteParameters::from_payment_params_and_value(
7958 payment_params, amt_msat);
7959 if let Err(LightningError { err, .. }) = get_route(
7960 &our_id, &route_params, &netgraph, None, Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes
7962 assert_eq!(err, "Failed to find a path to the given destination");
7967 fn min_htlc_overpay_violates_max_htlc() {
7968 do_min_htlc_overpay_violates_max_htlc(true);
7969 do_min_htlc_overpay_violates_max_htlc(false);
7971 fn do_min_htlc_overpay_violates_max_htlc(blinded_payee: bool) {
7972 // Test that if overpaying to meet a later hop's min_htlc and causes us to violate an earlier
7973 // hop's max_htlc, we don't consider that candidate hop valid. Previously we would add this hop
7974 // to `targets` and build an invalid path with it, and subsequently hit a debug panic asserting
7975 // that the used liquidity for a hop was less than its available liquidity limit.
7976 let secp_ctx = Secp256k1::new();
7977 let logger = Arc::new(ln_test_utils::TestLogger::new());
7978 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
7979 let scorer = ln_test_utils::TestScorer::new();
7980 let random_seed_bytes = [42; 32];
7981 let config = UserConfig::default();
7983 // Values are taken from the fuzz input that uncovered this panic.
7984 let amt_msat = 7_4009_8048;
7985 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
7986 let first_hop_outbound_capacity = 2_7345_2000;
7987 let first_hops = vec![get_channel_details(
7988 Some(200), nodes[0], channelmanager::provided_init_features(&config),
7989 first_hop_outbound_capacity
7992 let base_fee = 1_6778_3453;
7993 let htlc_min = 2_5165_8240;
7994 let payment_params = if blinded_payee {
7995 let blinded_path = BlindedPath {
7996 introduction_node: IntroductionNode::NodeId(nodes[0]),
7997 blinding_point: ln_test_utils::pubkey(42),
7999 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
8000 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
8003 let blinded_payinfo = BlindedPayInfo {
8004 fee_base_msat: base_fee,
8005 fee_proportional_millionths: 0,
8006 htlc_minimum_msat: htlc_min,
8007 htlc_maximum_msat: htlc_min * 1000,
8008 cltv_expiry_delta: 0,
8009 features: BlindedHopFeatures::empty(),
8011 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
8012 PaymentParameters::blinded(vec![(blinded_payinfo, blinded_path)])
8013 .with_bolt12_features(bolt12_features.clone()).unwrap()
8015 let route_hint = RouteHint(vec![RouteHintHop {
8016 src_node_id: nodes[0],
8017 short_channel_id: 42,
8019 base_msat: base_fee,
8020 proportional_millionths: 0,
8022 cltv_expiry_delta: 10,
8023 htlc_minimum_msat: Some(htlc_min),
8024 htlc_maximum_msat: None,
8027 PaymentParameters::from_node_id(nodes[1], 42)
8028 .with_route_hints(vec![route_hint]).unwrap()
8029 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap()
8032 let netgraph = network_graph.read_only();
8033 let route_params = RouteParameters::from_payment_params_and_value(
8034 payment_params, amt_msat);
8035 if let Err(LightningError { err, .. }) = get_route(
8036 &our_id, &route_params, &netgraph, Some(&first_hops.iter().collect::<Vec<_>>()),
8037 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes
8039 assert_eq!(err, "Failed to find a path to the given destination");
8044 fn previously_used_liquidity_violates_max_htlc() {
8045 do_previously_used_liquidity_violates_max_htlc(true);
8046 do_previously_used_liquidity_violates_max_htlc(false);
8049 fn do_previously_used_liquidity_violates_max_htlc(blinded_payee: bool) {
8050 // Test that if a candidate first_hop<>route_hint_src_node channel does not have enough
8051 // contribution amount to cover the next hop's min_htlc plus fees, we will not consider that
8052 // candidate. In this case, the candidate does not have enough due to a previous path taking up
8053 // some of its liquidity. Previously we would construct an invalid path and hit a debug panic
8054 // asserting that the used liquidity for a hop was less than its available liquidity limit.
8055 let secp_ctx = Secp256k1::new();
8056 let logger = Arc::new(ln_test_utils::TestLogger::new());
8057 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
8058 let scorer = ln_test_utils::TestScorer::new();
8059 let random_seed_bytes = [42; 32];
8060 let config = UserConfig::default();
8062 // Values are taken from the fuzz input that uncovered this panic.
8063 let amt_msat = 52_4288;
8064 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
8065 let first_hops = vec![get_channel_details(
8066 Some(161), nodes[0], channelmanager::provided_init_features(&config), 486_4000
8067 ), get_channel_details(
8068 Some(122), nodes[0], channelmanager::provided_init_features(&config), 179_5000
8071 let base_fees = [0, 425_9840, 0, 0];
8072 let htlc_mins = [1_4392, 19_7401, 1027, 6_5535];
8073 let payment_params = if blinded_payee {
8074 let blinded_path = BlindedPath {
8075 introduction_node: IntroductionNode::NodeId(nodes[0]),
8076 blinding_point: ln_test_utils::pubkey(42),
8078 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
8079 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
8082 let mut blinded_hints = Vec::new();
8083 for (base_fee, htlc_min) in base_fees.iter().zip(htlc_mins.iter()) {
8084 blinded_hints.push((BlindedPayInfo {
8085 fee_base_msat: *base_fee,
8086 fee_proportional_millionths: 0,
8087 htlc_minimum_msat: *htlc_min,
8088 htlc_maximum_msat: htlc_min * 100,
8089 cltv_expiry_delta: 10,
8090 features: BlindedHopFeatures::empty(),
8091 }, blinded_path.clone()));
8093 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
8094 PaymentParameters::blinded(blinded_hints.clone())
8095 .with_bolt12_features(bolt12_features.clone()).unwrap()
8097 let mut route_hints = Vec::new();
8098 for (idx, (base_fee, htlc_min)) in base_fees.iter().zip(htlc_mins.iter()).enumerate() {
8099 route_hints.push(RouteHint(vec![RouteHintHop {
8100 src_node_id: nodes[0],
8101 short_channel_id: 42 + idx as u64,
8103 base_msat: *base_fee,
8104 proportional_millionths: 0,
8106 cltv_expiry_delta: 10,
8107 htlc_minimum_msat: Some(*htlc_min),
8108 htlc_maximum_msat: Some(htlc_min * 100),
8111 PaymentParameters::from_node_id(nodes[1], 42)
8112 .with_route_hints(route_hints).unwrap()
8113 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap()
8116 let netgraph = network_graph.read_only();
8117 let route_params = RouteParameters::from_payment_params_and_value(
8118 payment_params, amt_msat);
8120 let route = get_route(
8121 &our_id, &route_params, &netgraph, Some(&first_hops.iter().collect::<Vec<_>>()),
8122 Arc::clone(&logger), &scorer, &Default::default(), &random_seed_bytes
8124 assert_eq!(route.paths.len(), 1);
8125 assert_eq!(route.get_total_amount(), amt_msat);
8129 fn candidate_path_min() {
8130 // Test that if a candidate first_hop<>network_node channel does not have enough contribution
8131 // amount to cover the next channel's min htlc plus fees, we will not consider that candidate.
8132 // Previously, we were storing RouteGraphNodes with a path_min that did not include fees, and
8133 // would add a connecting first_hop node that did not have enough contribution amount, leading
8134 // to a debug panic upon invalid path construction.
8135 let secp_ctx = Secp256k1::new();
8136 let logger = Arc::new(ln_test_utils::TestLogger::new());
8137 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
8138 let gossip_sync = P2PGossipSync::new(network_graph.clone(), None, logger.clone());
8139 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), network_graph.clone(), logger.clone());
8140 let random_seed_bytes = [42; 32];
8141 let config = UserConfig::default();
8143 // Values are taken from the fuzz input that uncovered this panic.
8144 let amt_msat = 7_4009_8048;
8145 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
8146 let first_hops = vec![get_channel_details(
8147 Some(200), nodes[0], channelmanager::provided_init_features(&config), 2_7345_2000
8150 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
8151 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
8152 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
8153 short_channel_id: 6,
8156 cltv_expiry_delta: (6 << 4) | 0,
8157 htlc_minimum_msat: 0,
8158 htlc_maximum_msat: MAX_VALUE_MSAT,
8160 fee_proportional_millionths: 0,
8161 excess_data: Vec::new()
8163 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
8165 let htlc_min = 2_5165_8240;
8166 let blinded_hints = vec![
8168 fee_base_msat: 1_6778_3453,
8169 fee_proportional_millionths: 0,
8170 htlc_minimum_msat: htlc_min,
8171 htlc_maximum_msat: htlc_min * 100,
8172 cltv_expiry_delta: 10,
8173 features: BlindedHopFeatures::empty(),
8175 introduction_node: IntroductionNode::NodeId(nodes[0]),
8176 blinding_point: ln_test_utils::pubkey(42),
8178 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
8179 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
8183 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
8184 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
8185 .with_bolt12_features(bolt12_features.clone()).unwrap();
8186 let route_params = RouteParameters::from_payment_params_and_value(
8187 payment_params, amt_msat);
8188 let netgraph = network_graph.read_only();
8190 if let Err(LightningError { err, .. }) = get_route(
8191 &our_id, &route_params, &netgraph, Some(&first_hops.iter().collect::<Vec<_>>()),
8192 Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(),
8195 assert_eq!(err, "Failed to find a path to the given destination");
8200 fn path_contribution_includes_min_htlc_overpay() {
8201 // Previously, the fuzzer hit a debug panic because we wouldn't include the amount overpaid to
8202 // meet a last hop's min_htlc in the total collected paths value. We now include this value and
8203 // also penalize hops along the overpaying path to ensure that it gets deprioritized in path
8204 // selection, both tested here.
8205 let secp_ctx = Secp256k1::new();
8206 let logger = Arc::new(ln_test_utils::TestLogger::new());
8207 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
8208 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), network_graph.clone(), logger.clone());
8209 let random_seed_bytes = [42; 32];
8210 let config = UserConfig::default();
8212 // Values are taken from the fuzz input that uncovered this panic.
8213 let amt_msat = 562_0000;
8214 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
8215 let first_hops = vec![
8216 get_channel_details(
8217 Some(83), nodes[0], channelmanager::provided_init_features(&config), 2199_0000,
8221 let htlc_mins = [49_0000, 1125_0000];
8222 let payment_params = {
8223 let blinded_path = BlindedPath {
8224 introduction_node: IntroductionNode::NodeId(nodes[0]),
8225 blinding_point: ln_test_utils::pubkey(42),
8227 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
8228 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
8231 let mut blinded_hints = Vec::new();
8232 for htlc_min in htlc_mins.iter() {
8233 blinded_hints.push((BlindedPayInfo {
8235 fee_proportional_millionths: 0,
8236 htlc_minimum_msat: *htlc_min,
8237 htlc_maximum_msat: *htlc_min * 100,
8238 cltv_expiry_delta: 10,
8239 features: BlindedHopFeatures::empty(),
8240 }, blinded_path.clone()));
8242 let bolt12_features = channelmanager::provided_bolt12_invoice_features(&config);
8243 PaymentParameters::blinded(blinded_hints.clone())
8244 .with_bolt12_features(bolt12_features.clone()).unwrap()
8247 let netgraph = network_graph.read_only();
8248 let route_params = RouteParameters::from_payment_params_and_value(
8249 payment_params, amt_msat);
8250 let route = get_route(
8251 &our_id, &route_params, &netgraph, Some(&first_hops.iter().collect::<Vec<_>>()),
8252 Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(),
8255 assert_eq!(route.paths.len(), 1);
8256 assert_eq!(route.get_total_amount(), amt_msat);
8260 fn first_hop_preferred_over_hint() {
8261 // Check that if we have a first hop to a peer we'd always prefer that over a route hint
8262 // they gave us, but we'd still consider all subsequent hints if they are more attractive.
8263 let secp_ctx = Secp256k1::new();
8264 let logger = Arc::new(ln_test_utils::TestLogger::new());
8265 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
8266 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
8267 let scorer = ln_test_utils::TestScorer::new();
8268 let random_seed_bytes = [42; 32];
8269 let config = UserConfig::default();
8271 let amt_msat = 1_000_000;
8272 let (our_privkey, our_node_id, privkeys, nodes) = get_nodes(&secp_ctx);
8274 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[0],
8275 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
8276 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
8277 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
8278 short_channel_id: 1,
8281 cltv_expiry_delta: 42,
8282 htlc_minimum_msat: 1_000,
8283 htlc_maximum_msat: 10_000_000,
8285 fee_proportional_millionths: 0,
8286 excess_data: Vec::new()
8288 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
8289 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
8290 short_channel_id: 1,
8293 cltv_expiry_delta: 42,
8294 htlc_minimum_msat: 1_000,
8295 htlc_maximum_msat: 10_000_000,
8297 fee_proportional_millionths: 0,
8298 excess_data: Vec::new()
8301 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[1],
8302 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 2);
8303 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
8304 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
8305 short_channel_id: 2,
8308 cltv_expiry_delta: 42,
8309 htlc_minimum_msat: 1_000,
8310 htlc_maximum_msat: 10_000_000,
8312 fee_proportional_millionths: 0,
8313 excess_data: Vec::new()
8315 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
8316 chain_hash: ChainHash::using_genesis_block(Network::Testnet),
8317 short_channel_id: 2,
8320 cltv_expiry_delta: 42,
8321 htlc_minimum_msat: 1_000,
8322 htlc_maximum_msat: 10_000_000,
8324 fee_proportional_millionths: 0,
8325 excess_data: Vec::new()
8328 let dest_node_id = nodes[2];
8330 let route_hint = RouteHint(vec![RouteHintHop {
8331 src_node_id: our_node_id,
8332 short_channel_id: 44,
8335 proportional_millionths: 0,
8337 cltv_expiry_delta: 10,
8338 htlc_minimum_msat: None,
8339 htlc_maximum_msat: Some(5_000_000),
8342 src_node_id: nodes[0],
8343 short_channel_id: 45,
8346 proportional_millionths: 0,
8348 cltv_expiry_delta: 10,
8349 htlc_minimum_msat: None,
8350 htlc_maximum_msat: None,
8353 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
8354 .with_route_hints(vec![route_hint]).unwrap()
8355 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap();
8356 let route_params = RouteParameters::from_payment_params_and_value(
8357 payment_params, amt_msat);
8359 // First create an insufficient first hop for channel with SCID 1 and check we'd use the
8361 let first_hop = get_channel_details(Some(1), nodes[0],
8362 channelmanager::provided_init_features(&config), 999_999);
8363 let first_hops = vec![first_hop];
8365 let route = get_route(&our_node_id, &route_params.clone(), &network_graph.read_only(),
8366 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
8367 &Default::default(), &random_seed_bytes).unwrap();
8368 assert_eq!(route.paths.len(), 1);
8369 assert_eq!(route.get_total_amount(), amt_msat);
8370 assert_eq!(route.paths[0].hops.len(), 2);
8371 assert_eq!(route.paths[0].hops[0].short_channel_id, 44);
8372 assert_eq!(route.paths[0].hops[1].short_channel_id, 45);
8373 assert_eq!(route.get_total_fees(), 123);
8375 // Now check we would trust our first hop info, i.e., fail if we detect the route hint is
8376 // for a first hop channel.
8377 let mut first_hop = get_channel_details(Some(1), nodes[0], channelmanager::provided_init_features(&config), 999_999);
8378 first_hop.outbound_scid_alias = Some(44);
8379 let first_hops = vec![first_hop];
8381 let route_res = get_route(&our_node_id, &route_params.clone(), &network_graph.read_only(),
8382 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
8383 &Default::default(), &random_seed_bytes);
8384 assert!(route_res.is_err());
8386 // Finally check we'd use the first hop if has sufficient outbound capacity. But we'd stil
8387 // use the cheaper second hop of the route hint.
8388 let mut first_hop = get_channel_details(Some(1), nodes[0],
8389 channelmanager::provided_init_features(&config), 10_000_000);
8390 first_hop.outbound_scid_alias = Some(44);
8391 let first_hops = vec![first_hop];
8393 let route = get_route(&our_node_id, &route_params.clone(), &network_graph.read_only(),
8394 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
8395 &Default::default(), &random_seed_bytes).unwrap();
8396 assert_eq!(route.paths.len(), 1);
8397 assert_eq!(route.get_total_amount(), amt_msat);
8398 assert_eq!(route.paths[0].hops.len(), 2);
8399 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
8400 assert_eq!(route.paths[0].hops[1].short_channel_id, 45);
8401 assert_eq!(route.get_total_fees(), 123);
8405 fn allow_us_being_first_hint() {
8406 // Check that we consider a route hint even if we are the src of the first hop.
8407 let secp_ctx = Secp256k1::new();
8408 let logger = Arc::new(ln_test_utils::TestLogger::new());
8409 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
8410 let scorer = ln_test_utils::TestScorer::new();
8411 let random_seed_bytes = [42; 32];
8412 let config = UserConfig::default();
8414 let (_, our_node_id, _, nodes) = get_nodes(&secp_ctx);
8416 let amt_msat = 1_000_000;
8417 let dest_node_id = nodes[1];
8419 let first_hop = get_channel_details(Some(1), nodes[0], channelmanager::provided_init_features(&config), 10_000_000);
8420 let first_hops = vec![first_hop];
8422 let route_hint = RouteHint(vec![RouteHintHop {
8423 src_node_id: our_node_id,
8424 short_channel_id: 44,
8427 proportional_millionths: 0,
8429 cltv_expiry_delta: 10,
8430 htlc_minimum_msat: None,
8431 htlc_maximum_msat: None,
8434 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
8435 .with_route_hints(vec![route_hint]).unwrap()
8436 .with_bolt11_features(channelmanager::provided_bolt11_invoice_features(&config)).unwrap();
8438 let route_params = RouteParameters::from_payment_params_and_value(
8439 payment_params, amt_msat);
8442 let route = get_route(&our_node_id, &route_params, &network_graph.read_only(),
8443 Some(&first_hops.iter().collect::<Vec<_>>()), Arc::clone(&logger), &scorer,
8444 &Default::default(), &random_seed_bytes).unwrap();
8446 assert_eq!(route.paths.len(), 1);
8447 assert_eq!(route.get_total_amount(), amt_msat);
8448 assert_eq!(route.get_total_fees(), 0);
8449 assert_eq!(route.paths[0].hops.len(), 1);
8451 assert_eq!(route.paths[0].hops[0].short_channel_id, 44);
8455 #[cfg(all(any(test, ldk_bench), feature = "std"))]
8456 pub(crate) mod bench_utils {
8460 use bitcoin::hashes::Hash;
8461 use bitcoin::secp256k1::SecretKey;
8463 use crate::chain::transaction::OutPoint;
8464 use crate::routing::scoring::{ProbabilisticScorer, ScoreUpdate};
8465 use crate::ln::channel_state::{ChannelCounterparty, ChannelShutdownState};
8466 use crate::ln::channelmanager;
8467 use crate::ln::types::ChannelId;
8468 use crate::util::config::UserConfig;
8469 use crate::util::test_utils::TestLogger;
8470 use crate::sync::Arc;
8472 /// Tries to open a network graph file, or panics with a URL to fetch it.
8473 pub(crate) fn get_graph_scorer_file() -> Result<(std::fs::File, std::fs::File), &'static str> {
8474 let load_file = |fname, err_str| {
8475 File::open(fname) // By default we're run in RL/lightning
8476 .or_else(|_| File::open(&format!("lightning/{}", fname))) // We may be run manually in RL/
8477 .or_else(|_| { // Fall back to guessing based on the binary location
8478 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
8479 let mut path = std::env::current_exe().unwrap();
8480 path.pop(); // lightning-...
8482 path.pop(); // debug
8483 path.pop(); // target
8484 path.push("lightning");
8488 .or_else(|_| { // Fall back to guessing based on the binary location for a subcrate
8489 // path is likely something like .../rust-lightning/bench/target/debug/deps/bench..
8490 let mut path = std::env::current_exe().unwrap();
8491 path.pop(); // bench...
8493 path.pop(); // debug
8494 path.pop(); // target
8495 path.pop(); // bench
8496 path.push("lightning");
8500 .map_err(|_| err_str)
8502 let graph_res = load_file(
8503 "net_graph-2023-12-10.bin",
8504 "Please fetch https://bitcoin.ninja/ldk-net_graph-v0.0.118-2023-12-10.bin and place it at lightning/net_graph-2023-12-10.bin"
8506 let scorer_res = load_file(
8507 "scorer-2023-12-10.bin",
8508 "Please fetch https://bitcoin.ninja/ldk-scorer-v0.0.118-2023-12-10.bin and place it at lightning/scorer-2023-12-10.bin"
8510 #[cfg(require_route_graph_test)]
8511 return Ok((graph_res.unwrap(), scorer_res.unwrap()));
8512 #[cfg(not(require_route_graph_test))]
8513 return Ok((graph_res?, scorer_res?));
8516 pub(crate) fn read_graph_scorer(logger: &TestLogger)
8517 -> Result<(Arc<NetworkGraph<&TestLogger>>, ProbabilisticScorer<Arc<NetworkGraph<&TestLogger>>, &TestLogger>), &'static str> {
8518 let (mut graph_file, mut scorer_file) = get_graph_scorer_file()?;
8519 let graph = Arc::new(NetworkGraph::read(&mut graph_file, logger).unwrap());
8520 let scorer_args = (Default::default(), Arc::clone(&graph), logger);
8521 let scorer = ProbabilisticScorer::read(&mut scorer_file, scorer_args).unwrap();
8525 pub(crate) fn payer_pubkey() -> PublicKey {
8526 let secp_ctx = Secp256k1::new();
8527 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
8531 pub(crate) fn first_hop(node_id: PublicKey) -> ChannelDetails {
8533 channel_id: ChannelId::new_zero(),
8534 counterparty: ChannelCounterparty {
8535 features: channelmanager::provided_init_features(&UserConfig::default()),
8537 unspendable_punishment_reserve: 0,
8538 forwarding_info: None,
8539 outbound_htlc_minimum_msat: None,
8540 outbound_htlc_maximum_msat: None,
8542 funding_txo: Some(OutPoint {
8543 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
8546 short_channel_id: Some(1),
8547 inbound_scid_alias: None,
8548 outbound_scid_alias: None,
8549 channel_value_satoshis: 10_000_000_000,
8551 balance_msat: 10_000_000_000,
8552 outbound_capacity_msat: 10_000_000_000,
8553 next_outbound_htlc_minimum_msat: 0,
8554 next_outbound_htlc_limit_msat: 10_000_000_000,
8555 inbound_capacity_msat: 0,
8556 unspendable_punishment_reserve: None,
8557 confirmations_required: None,
8558 confirmations: None,
8559 force_close_spend_delay: None,
8561 is_channel_ready: true,
8564 inbound_htlc_minimum_msat: None,
8565 inbound_htlc_maximum_msat: None,
8567 feerate_sat_per_1000_weight: None,
8568 channel_shutdown_state: Some(ChannelShutdownState::NotShuttingDown),
8569 pending_inbound_htlcs: Vec::new(),
8570 pending_outbound_htlcs: Vec::new(),
8574 pub(crate) fn generate_test_routes<S: ScoreLookUp + ScoreUpdate>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
8575 score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, mut seed: u64,
8576 starting_amount: u64, route_count: usize,
8577 ) -> Vec<(ChannelDetails, PaymentParameters, u64)> {
8578 let payer = payer_pubkey();
8579 let random_seed_bytes = [42; 32];
8581 let nodes = graph.read_only().nodes().clone();
8582 let mut route_endpoints = Vec::new();
8583 for _ in 0..route_count {
8585 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
8586 let src = PublicKey::from_slice(nodes.unordered_keys()
8587 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
8588 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
8589 let dst = PublicKey::from_slice(nodes.unordered_keys()
8590 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
8591 let params = PaymentParameters::from_node_id(dst, 42)
8592 .with_bolt11_features(features.clone()).unwrap();
8593 let first_hop = first_hop(src);
8594 let amt_msat = starting_amount + seed % 1_000_000;
8595 let route_params = RouteParameters::from_payment_params_and_value(
8596 params.clone(), amt_msat);
8598 get_route(&payer, &route_params, &graph.read_only(), Some(&[&first_hop]),
8599 &TestLogger::new(), scorer, score_params, &random_seed_bytes).is_ok();
8601 route_endpoints.push((first_hop, params, amt_msat));
8614 use crate::routing::scoring::{ScoreUpdate, ScoreLookUp};
8615 use crate::ln::channelmanager;
8616 use crate::ln::features::Bolt11InvoiceFeatures;
8617 use crate::routing::gossip::NetworkGraph;
8618 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScoringFeeParameters};
8619 use crate::util::config::UserConfig;
8620 use crate::util::logger::{Logger, Record};
8621 use crate::util::test_utils::TestLogger;
8623 use criterion::Criterion;
8625 struct DummyLogger {}
8626 impl Logger for DummyLogger {
8627 fn log(&self, _record: Record) {}
8630 pub fn generate_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
8631 let logger = TestLogger::new();
8632 let (network_graph, _) = bench_utils::read_graph_scorer(&logger).unwrap();
8633 let scorer = FixedPenaltyScorer::with_penalty(0);
8634 generate_routes(bench, &network_graph, scorer, &Default::default(),
8635 Bolt11InvoiceFeatures::empty(), 0, "generate_routes_with_zero_penalty_scorer");
8638 pub fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
8639 let logger = TestLogger::new();
8640 let (network_graph, _) = bench_utils::read_graph_scorer(&logger).unwrap();
8641 let scorer = FixedPenaltyScorer::with_penalty(0);
8642 generate_routes(bench, &network_graph, scorer, &Default::default(),
8643 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 0,
8644 "generate_mpp_routes_with_zero_penalty_scorer");
8647 pub fn generate_routes_with_probabilistic_scorer(bench: &mut Criterion) {
8648 let logger = TestLogger::new();
8649 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8650 let params = ProbabilisticScoringFeeParameters::default();
8651 generate_routes(bench, &network_graph, scorer, ¶ms, Bolt11InvoiceFeatures::empty(), 0,
8652 "generate_routes_with_probabilistic_scorer");
8655 pub fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
8656 let logger = TestLogger::new();
8657 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8658 let params = ProbabilisticScoringFeeParameters::default();
8659 generate_routes(bench, &network_graph, scorer, ¶ms,
8660 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 0,
8661 "generate_mpp_routes_with_probabilistic_scorer");
8664 pub fn generate_large_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
8665 let logger = TestLogger::new();
8666 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8667 let params = ProbabilisticScoringFeeParameters::default();
8668 generate_routes(bench, &network_graph, scorer, ¶ms,
8669 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 100_000_000,
8670 "generate_large_mpp_routes_with_probabilistic_scorer");
8673 pub fn generate_routes_with_nonlinear_probabilistic_scorer(bench: &mut Criterion) {
8674 let logger = TestLogger::new();
8675 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8676 let mut params = ProbabilisticScoringFeeParameters::default();
8677 params.linear_success_probability = false;
8678 generate_routes(bench, &network_graph, scorer, ¶ms,
8679 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 0,
8680 "generate_routes_with_nonlinear_probabilistic_scorer");
8683 pub fn generate_mpp_routes_with_nonlinear_probabilistic_scorer(bench: &mut Criterion) {
8684 let logger = TestLogger::new();
8685 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8686 let mut params = ProbabilisticScoringFeeParameters::default();
8687 params.linear_success_probability = false;
8688 generate_routes(bench, &network_graph, scorer, ¶ms,
8689 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 0,
8690 "generate_mpp_routes_with_nonlinear_probabilistic_scorer");
8693 pub fn generate_large_mpp_routes_with_nonlinear_probabilistic_scorer(bench: &mut Criterion) {
8694 let logger = TestLogger::new();
8695 let (network_graph, scorer) = bench_utils::read_graph_scorer(&logger).unwrap();
8696 let mut params = ProbabilisticScoringFeeParameters::default();
8697 params.linear_success_probability = false;
8698 generate_routes(bench, &network_graph, scorer, ¶ms,
8699 channelmanager::provided_bolt11_invoice_features(&UserConfig::default()), 100_000_000,
8700 "generate_large_mpp_routes_with_nonlinear_probabilistic_scorer");
8703 fn generate_routes<S: ScoreLookUp + ScoreUpdate>(
8704 bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, mut scorer: S,
8705 score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, starting_amount: u64,
8706 bench_name: &'static str,
8708 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
8709 let route_endpoints = bench_utils::generate_test_routes(graph, &mut scorer, score_params, features, 0xdeadbeef, starting_amount, 50);
8711 // ...then benchmark finding paths between the nodes we learned.
8712 do_route_bench(bench, graph, scorer, score_params, bench_name, route_endpoints);
8716 fn do_route_bench<S: ScoreLookUp + ScoreUpdate>(
8717 bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, scorer: S,
8718 score_params: &S::ScoreParams, bench_name: &'static str,
8719 route_endpoints: Vec<(ChannelDetails, PaymentParameters, u64)>,
8721 let payer = bench_utils::payer_pubkey();
8722 let random_seed_bytes = [42; 32];
8725 bench.bench_function(bench_name, |b| b.iter(|| {
8726 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
8727 let route_params = RouteParameters::from_payment_params_and_value(params.clone(), *amt);
8728 assert!(get_route(&payer, &route_params, &graph.read_only(), Some(&[first_hop]),
8729 &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok());