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;
13 use bitcoin::hashes::Hash;
14 use bitcoin::hashes::sha256::Hash as Sha256;
16 use crate::blinded_path::{BlindedHop, BlindedPath};
17 use crate::ln::PaymentHash;
18 use crate::ln::channelmanager::{ChannelDetails, PaymentId};
19 use crate::ln::features::{Bolt12InvoiceFeatures, ChannelFeatures, InvoiceFeatures, NodeFeatures};
20 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
21 use crate::offers::invoice::BlindedPayInfo;
22 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
23 use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
24 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
25 use crate::util::logger::{Level, Logger};
26 use crate::util::chacha20::ChaCha20;
29 use crate::prelude::*;
30 use crate::sync::{Mutex, MutexGuard};
31 use alloc::collections::BinaryHeap;
35 /// A [`Router`] implemented using [`find_route`].
36 pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> where
38 S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
42 random_seed_bytes: Mutex<[u8; 32]>,
47 impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> DefaultRouter<G, L, S, SP, Sc> where
49 S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
51 /// Creates a new router.
52 pub fn new(network_graph: G, logger: L, random_seed_bytes: [u8; 32], scorer: S, score_params: SP) -> Self {
53 let random_seed_bytes = Mutex::new(random_seed_bytes);
54 Self { network_graph, logger, random_seed_bytes, scorer, score_params }
58 impl< G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref, SP: Sized, Sc: Score<ScoreParams = SP>> Router for DefaultRouter<G, L, S, SP, Sc> where
60 S::Target: for <'a> LockableScore<'a, Locked = MutexGuard<'a, Sc>>,
65 params: &RouteParameters,
66 first_hops: Option<&[&ChannelDetails]>,
67 inflight_htlcs: &InFlightHtlcs
68 ) -> Result<Route, LightningError> {
69 let random_seed_bytes = {
70 let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
71 *locked_random_seed_bytes = Sha256::hash(&*locked_random_seed_bytes).into_inner();
72 *locked_random_seed_bytes
75 payer, params, &self.network_graph, first_hops, &*self.logger,
76 &ScorerAccountingForInFlightHtlcs::new(self.scorer.lock(), inflight_htlcs),
83 /// A trait defining behavior for routing a payment.
85 /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
87 &self, payer: &PublicKey, route_params: &RouteParameters,
88 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
89 ) -> Result<Route, LightningError>;
90 /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values. Includes
91 /// `PaymentHash` and `PaymentId` to be able to correlate the request with a specific payment.
92 fn find_route_with_id(
93 &self, payer: &PublicKey, route_params: &RouteParameters,
94 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs,
95 _payment_hash: PaymentHash, _payment_id: PaymentId
96 ) -> Result<Route, LightningError> {
97 self.find_route(payer, route_params, first_hops, inflight_htlcs)
101 /// [`Score`] implementation that factors in in-flight HTLC liquidity.
103 /// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
106 /// [`Score`]: crate::routing::scoring::Score
107 pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score> {
109 // Maps a channel's short channel id and its direction to the liquidity used up.
110 inflight_htlcs: &'a InFlightHtlcs,
113 impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
114 /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
115 pub fn new(scorer: S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
116 ScorerAccountingForInFlightHtlcs {
124 impl<'a, S: Score> Writeable for ScorerAccountingForInFlightHtlcs<'a, S> {
125 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
128 impl<'a, S: Score> Score for ScorerAccountingForInFlightHtlcs<'a, S> {
129 type ScoreParams = S::ScoreParams;
130 fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 {
131 if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
132 source, target, short_channel_id
134 let usage = ChannelUsage {
135 inflight_htlc_msat: usage.inflight_htlc_msat + used_liquidity,
139 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
141 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
145 fn payment_path_failed(&mut self, path: &Path, short_channel_id: u64) {
146 self.scorer.payment_path_failed(path, short_channel_id)
149 fn payment_path_successful(&mut self, path: &Path) {
150 self.scorer.payment_path_successful(path)
153 fn probe_failed(&mut self, path: &Path, short_channel_id: u64) {
154 self.scorer.probe_failed(path, short_channel_id)
157 fn probe_successful(&mut self, path: &Path) {
158 self.scorer.probe_successful(path)
162 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
163 /// in-use channel liquidity.
165 pub struct InFlightHtlcs(
166 // A map with liquidity value (in msat) keyed by a short channel id and the direction the HTLC
167 // is traveling in. The direction boolean is determined by checking if the HTLC source's public
168 // key is less than its destination. See `InFlightHtlcs::used_liquidity_msat` for more
170 HashMap<(u64, bool), u64>
174 /// Constructs an empty `InFlightHtlcs`.
175 pub fn new() -> Self { InFlightHtlcs(HashMap::new()) }
177 /// Takes in a path with payer's node id and adds the path's details to `InFlightHtlcs`.
178 pub fn process_path(&mut self, path: &Path, payer_node_id: PublicKey) {
179 if path.hops.is_empty() { return };
181 let mut cumulative_msat = 0;
182 if let Some(tail) = &path.blinded_tail {
183 cumulative_msat += tail.final_value_msat;
186 // total_inflight_map needs to be direction-sensitive when keeping track of the HTLC value
187 // that is held up. However, the `hops` array, which is a path returned by `find_route` in
188 // the router excludes the payer node. In the following lines, the payer's information is
189 // hardcoded with an inflight value of 0 so that we can correctly represent the first hop
190 // in our sliding window of two.
191 let reversed_hops_with_payer = path.hops.iter().rev().skip(1)
192 .map(|hop| hop.pubkey)
193 .chain(core::iter::once(payer_node_id));
195 // Taking the reversed vector from above, we zip it with just the reversed hops list to
196 // work "backwards" of the given path, since the last hop's `fee_msat` actually represents
197 // the total amount sent.
198 for (next_hop, prev_hop) in path.hops.iter().rev().zip(reversed_hops_with_payer) {
199 cumulative_msat += next_hop.fee_msat;
201 .entry((next_hop.short_channel_id, NodeId::from_pubkey(&prev_hop) < NodeId::from_pubkey(&next_hop.pubkey)))
202 .and_modify(|used_liquidity_msat| *used_liquidity_msat += cumulative_msat)
203 .or_insert(cumulative_msat);
207 /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
209 pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
210 self.0.get(&(channel_scid, source < target)).map(|v| *v)
214 impl Writeable for InFlightHtlcs {
215 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
218 impl Readable for InFlightHtlcs {
219 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
220 let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
221 Ok(Self(infight_map))
225 /// A hop in a route, and additional metadata about it. "Hop" is defined as a node and the channel
226 /// that leads to it.
227 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
228 pub struct RouteHop {
229 /// The node_id of the node at this hop.
230 pub pubkey: PublicKey,
231 /// The node_announcement features of the node at this hop. For the last hop, these may be
232 /// amended to match the features present in the invoice this node generated.
233 pub node_features: NodeFeatures,
234 /// The channel that should be used from the previous hop to reach this node.
235 pub short_channel_id: u64,
236 /// The channel_announcement features of the channel that should be used from the previous hop
237 /// to reach this node.
238 pub channel_features: ChannelFeatures,
239 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
240 /// If this is the last hop in [`Path::hops`]:
241 /// * if we're sending to a [`BlindedPath`], this is the fee paid for use of the entire blinded path
242 /// * otherwise, this is the full value of this [`Path`]'s part of the payment
244 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
246 /// The CLTV delta added for this hop.
247 /// If this is the last hop in [`Path::hops`]:
248 /// * if we're sending to a [`BlindedPath`], this is the CLTV delta for the entire blinded path
249 /// * otherwise, this is the CLTV delta expected at the destination
251 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
252 pub cltv_expiry_delta: u32,
255 impl_writeable_tlv_based!(RouteHop, {
256 (0, pubkey, required),
257 (2, node_features, required),
258 (4, short_channel_id, required),
259 (6, channel_features, required),
260 (8, fee_msat, required),
261 (10, cltv_expiry_delta, required),
264 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
265 /// their BOLT12 [`Invoice`].
267 /// [`Invoice`]: crate::offers::invoice::Invoice
268 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
269 pub struct BlindedTail {
270 /// The hops of the [`BlindedPath`] provided by the recipient.
272 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
273 pub hops: Vec<BlindedHop>,
274 /// The blinding point of the [`BlindedPath`] provided by the recipient.
276 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
277 pub blinding_point: PublicKey,
278 /// Excess CLTV delta added to the recipient's CLTV expiry to deter intermediate nodes from
279 /// inferring the destination. May be 0.
280 pub excess_final_cltv_expiry_delta: u32,
281 /// The total amount paid on this [`Path`], excluding the fees.
282 pub final_value_msat: u64,
285 impl_writeable_tlv_based!(BlindedTail, {
287 (2, blinding_point, required),
288 (4, excess_final_cltv_expiry_delta, required),
289 (6, final_value_msat, required),
292 /// A path in a [`Route`] to the payment recipient. Must always be at least length one.
293 /// If no [`Path::blinded_tail`] is present, then [`Path::hops`] length may be up to 19.
294 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
296 /// The list of unblinded hops in this [`Path`]. Must be at least length one.
297 pub hops: Vec<RouteHop>,
298 /// The blinded path at which this path terminates, if we're sending to one, and its metadata.
299 pub blinded_tail: Option<BlindedTail>,
303 /// Gets the fees for a given path, excluding any excess paid to the recipient.
304 pub fn fee_msat(&self) -> u64 {
305 match &self.blinded_tail {
306 Some(_) => self.hops.iter().map(|hop| hop.fee_msat).sum::<u64>(),
308 // Do not count last hop of each path since that's the full value of the payment
309 self.hops.split_last().map_or(0,
310 |(_, path_prefix)| path_prefix.iter().map(|hop| hop.fee_msat).sum())
315 /// Gets the total amount paid on this [`Path`], excluding the fees.
316 pub fn final_value_msat(&self) -> u64 {
317 match &self.blinded_tail {
318 Some(blinded_tail) => blinded_tail.final_value_msat,
319 None => self.hops.last().map_or(0, |hop| hop.fee_msat)
323 /// Gets the final hop's CLTV expiry delta.
324 pub fn final_cltv_expiry_delta(&self) -> Option<u32> {
325 match &self.blinded_tail {
327 None => self.hops.last().map(|hop| hop.cltv_expiry_delta)
332 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
333 /// it can take multiple paths. Each path is composed of one or more hops through the network.
334 #[derive(Clone, Hash, PartialEq, Eq)]
336 /// The list of [`Path`]s taken for a single (potentially-)multi-part payment. If no
337 /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
339 pub paths: Vec<Path>,
340 /// The `payment_params` parameter passed to [`find_route`].
341 /// This is used by `ChannelManager` to track information which may be required for retries,
342 /// provided back to you via [`Event::PaymentPathFailed`].
344 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
345 pub payment_params: Option<PaymentParameters>,
349 /// Returns the total amount of fees paid on this [`Route`].
351 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
352 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
353 pub fn get_total_fees(&self) -> u64 {
354 self.paths.iter().map(|path| path.fee_msat()).sum()
357 /// Returns the total amount paid on this [`Route`], excluding the fees. Might be more than
358 /// requested if we had to reach htlc_minimum_msat.
359 pub fn get_total_amount(&self) -> u64 {
360 self.paths.iter().map(|path| path.final_value_msat()).sum()
364 const SERIALIZATION_VERSION: u8 = 1;
365 const MIN_SERIALIZATION_VERSION: u8 = 1;
367 impl Writeable for Route {
368 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
369 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
370 (self.paths.len() as u64).write(writer)?;
371 let mut blinded_tails = Vec::new();
372 for path in self.paths.iter() {
373 (path.hops.len() as u8).write(writer)?;
374 for (idx, hop) in path.hops.iter().enumerate() {
376 if let Some(blinded_tail) = &path.blinded_tail {
377 if blinded_tails.is_empty() {
378 blinded_tails = Vec::with_capacity(path.hops.len());
380 blinded_tails.push(None);
383 blinded_tails.push(Some(blinded_tail));
384 } else if !blinded_tails.is_empty() { blinded_tails.push(None); }
387 write_tlv_fields!(writer, {
388 (1, self.payment_params, option),
389 (2, blinded_tails, optional_vec),
395 impl Readable for Route {
396 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
397 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
398 let path_count: u64 = Readable::read(reader)?;
399 if path_count == 0 { return Err(DecodeError::InvalidValue); }
400 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
401 let mut min_final_cltv_expiry_delta = u32::max_value();
402 for _ in 0..path_count {
403 let hop_count: u8 = Readable::read(reader)?;
404 let mut hops: Vec<RouteHop> = Vec::with_capacity(hop_count as usize);
405 for _ in 0..hop_count {
406 hops.push(Readable::read(reader)?);
408 if hops.is_empty() { return Err(DecodeError::InvalidValue); }
409 min_final_cltv_expiry_delta =
410 cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
411 paths.push(Path { hops, blinded_tail: None });
413 _init_and_read_tlv_fields!(reader, {
414 (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
415 (2, blinded_tails, optional_vec),
417 let blinded_tails = blinded_tails.unwrap_or(Vec::new());
418 if blinded_tails.len() != 0 {
419 if blinded_tails.len() != paths.len() { return Err(DecodeError::InvalidValue) }
420 for (mut path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
421 path.blinded_tail = blinded_tail_opt;
424 Ok(Route { paths, payment_params })
428 /// Parameters needed to find a [`Route`].
430 /// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
431 /// [`Event::PaymentPathFailed`].
433 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
434 #[derive(Clone, Debug, PartialEq, Eq)]
435 pub struct RouteParameters {
436 /// The parameters of the failed payment path.
437 pub payment_params: PaymentParameters,
439 /// The amount in msats sent on the failed payment path.
440 pub final_value_msat: u64,
443 impl Writeable for RouteParameters {
444 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
445 write_tlv_fields!(writer, {
446 (0, self.payment_params, required),
447 (2, self.final_value_msat, required),
448 // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
449 // `RouteParameters` directly. For compatibility, we write it here.
450 (4, self.payment_params.payee.final_cltv_expiry_delta(), option),
456 impl Readable for RouteParameters {
457 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
458 _init_and_read_tlv_fields!(reader, {
459 (0, payment_params, (required: ReadableArgs, 0)),
460 (2, final_value_msat, required),
461 (4, final_cltv_delta, option),
463 let mut payment_params: PaymentParameters = payment_params.0.unwrap();
464 if let Payee::Clear { ref mut final_cltv_expiry_delta, .. } = payment_params.payee {
465 if final_cltv_expiry_delta == &0 {
466 *final_cltv_expiry_delta = final_cltv_delta.ok_or(DecodeError::InvalidValue)?;
471 final_value_msat: final_value_msat.0.unwrap(),
476 /// Maximum total CTLV difference we allow for a full payment path.
477 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
479 /// Maximum number of paths we allow an (MPP) payment to have.
480 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
481 // limits, but for now more than 10 paths likely carries too much one-path failure.
482 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
484 // The median hop CLTV expiry delta currently seen in the network.
485 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
487 // During routing, we only consider paths shorter than our maximum length estimate.
488 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
489 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
490 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
492 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
493 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
494 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
495 // (payment_secret and total_msat) = 93 bytes for the final hop.
496 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
497 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
498 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
500 /// Information used to route a payment.
501 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
502 pub struct PaymentParameters {
503 /// Information about the payee, such as their features and route hints for their channels.
506 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
507 pub expiry_time: Option<u64>,
509 /// The maximum total CLTV delta we accept for the route.
510 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
511 pub max_total_cltv_expiry_delta: u32,
513 /// The maximum number of paths that may be used by (MPP) payments.
514 /// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
515 pub max_path_count: u8,
517 /// Selects the maximum share of a channel's total capacity which will be sent over a channel,
518 /// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
519 /// a lower value prefers to send larger MPP parts, potentially saturating channels and
520 /// increasing failure probability for those paths.
522 /// Note that this restriction will be relaxed during pathfinding after paths which meet this
523 /// restriction have been found. While paths which meet this criteria will be searched for, it
524 /// is ultimately up to the scorer to select them over other paths.
526 /// A value of 0 will allow payments up to and including a channel's total announced usable
527 /// capacity, a value of one will only use up to half its capacity, two 1/4, etc.
530 pub max_channel_saturation_power_of_half: u8,
532 /// A list of SCIDs which this payment was previously attempted over and which caused the
533 /// payment to fail. Future attempts for the same payment shouldn't be relayed through any of
535 pub previously_failed_channels: Vec<u64>,
538 impl Writeable for PaymentParameters {
539 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
540 let mut clear_hints = &vec![];
541 let mut blinded_hints = &vec![];
543 Payee::Clear { route_hints, .. } => clear_hints = route_hints,
544 Payee::Blinded { route_hints, .. } => blinded_hints = route_hints,
546 write_tlv_fields!(writer, {
547 (0, self.payee.node_id(), option),
548 (1, self.max_total_cltv_expiry_delta, required),
549 (2, self.payee.features(), option),
550 (3, self.max_path_count, required),
551 (4, *clear_hints, vec_type),
552 (5, self.max_channel_saturation_power_of_half, required),
553 (6, self.expiry_time, option),
554 (7, self.previously_failed_channels, vec_type),
555 (8, *blinded_hints, optional_vec),
556 (9, self.payee.final_cltv_expiry_delta(), option),
562 impl ReadableArgs<u32> for PaymentParameters {
563 fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
564 _init_and_read_tlv_fields!(reader, {
565 (0, payee_pubkey, option),
566 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
567 (2, features, (option: ReadableArgs, payee_pubkey.is_some())),
568 (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
569 (4, route_hints, vec_type),
570 (5, max_channel_saturation_power_of_half, (default_value, 2)),
571 (6, expiry_time, option),
572 (7, previously_failed_channels, vec_type),
573 (8, blinded_route_hints, optional_vec),
574 (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
576 let clear_route_hints = route_hints.unwrap_or(vec![]);
577 let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
578 let payee = if blinded_route_hints.len() != 0 {
579 if clear_route_hints.len() != 0 || payee_pubkey.is_some() { return Err(DecodeError::InvalidValue) }
581 route_hints: blinded_route_hints,
582 features: features.and_then(|f: Features| f.bolt12()),
586 route_hints: clear_route_hints,
587 node_id: payee_pubkey.ok_or(DecodeError::InvalidValue)?,
588 features: features.and_then(|f| f.bolt11()),
589 final_cltv_expiry_delta: final_cltv_expiry_delta.0.unwrap(),
593 max_total_cltv_expiry_delta: _init_tlv_based_struct_field!(max_total_cltv_expiry_delta, (default_value, unused)),
594 max_path_count: _init_tlv_based_struct_field!(max_path_count, (default_value, unused)),
596 max_channel_saturation_power_of_half: _init_tlv_based_struct_field!(max_channel_saturation_power_of_half, (default_value, unused)),
598 previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
604 impl PaymentParameters {
605 /// Creates a payee with the node id of the given `pubkey`.
607 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
609 pub fn from_node_id(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
611 payee: Payee::Clear { node_id: payee_pubkey, route_hints: vec![], features: None, final_cltv_expiry_delta },
613 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
614 max_path_count: DEFAULT_MAX_PATH_COUNT,
615 max_channel_saturation_power_of_half: 2,
616 previously_failed_channels: Vec::new(),
620 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
622 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
625 /// Note that MPP keysend is not widely supported yet. The `allow_mpp` lets you choose
626 /// whether your router will be allowed to find a multi-part route for this payment. If you
627 /// set `allow_mpp` to true, you should ensure a payment secret is set on send, likely via
628 /// [`RecipientOnionFields::secret_only`].
630 /// [`RecipientOnionFields::secret_only`]: crate::ln::channelmanager::RecipientOnionFields::secret_only
631 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32, allow_mpp: bool) -> Self {
632 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta)
633 .with_bolt11_features(InvoiceFeatures::for_keysend(allow_mpp))
634 .expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
637 /// Includes the payee's features. Errors if the parameters were initialized with blinded payment
640 /// This is not exported to bindings users since bindings don't support move semantics
641 pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
643 Payee::Blinded { .. } => Err(()),
644 Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
646 payee: Payee::Clear {
647 route_hints, node_id, features: Some(features), final_cltv_expiry_delta
653 /// Includes hints for routing to the payee. Errors if the parameters were initialized with
654 /// blinded payment paths.
656 /// This is not exported to bindings users since bindings don't support move semantics
657 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
659 Payee::Blinded { .. } => Err(()),
660 Payee::Clear { node_id, features, final_cltv_expiry_delta, .. } =>
662 payee: Payee::Clear {
663 route_hints, node_id, features, final_cltv_expiry_delta,
669 /// Includes a payment expiration in seconds relative to the UNIX epoch.
671 /// This is not exported to bindings users since bindings don't support move semantics
672 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
673 Self { expiry_time: Some(expiry_time), ..self }
676 /// Includes a limit for the total CLTV expiry delta which is considered during routing
678 /// This is not exported to bindings users since bindings don't support move semantics
679 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
680 Self { max_total_cltv_expiry_delta, ..self }
683 /// Includes a limit for the maximum number of payment paths that may be used.
685 /// This is not exported to bindings users since bindings don't support move semantics
686 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
687 Self { max_path_count, ..self }
690 /// Includes a limit for the maximum number of payment paths that may be used.
692 /// This is not exported to bindings users since bindings don't support move semantics
693 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
694 Self { max_channel_saturation_power_of_half, ..self }
698 /// The recipient of a payment, differing based on whether they've hidden their identity with route
700 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
702 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
703 /// will be included in the final [`Route`].
705 /// Aggregated routing info and blinded paths, for routing to the payee without knowing their
707 route_hints: Vec<(BlindedPayInfo, BlindedPath)>,
708 /// Features supported by the payee.
710 /// May be set from the payee's invoice. May be `None` if the invoice does not contain any
712 features: Option<Bolt12InvoiceFeatures>,
714 /// The recipient included these route hints in their BOLT11 invoice.
716 /// The node id of the payee.
718 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
719 route_hints: Vec<RouteHint>,
720 /// Features supported by the payee.
722 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
723 /// does not contain any features.
725 /// [`for_keysend`]: PaymentParameters::for_keysend
726 features: Option<InvoiceFeatures>,
727 /// The minimum CLTV delta at the end of the route. This value must not be zero.
728 final_cltv_expiry_delta: u32,
733 fn node_id(&self) -> Option<PublicKey> {
735 Self::Clear { node_id, .. } => Some(*node_id),
739 fn node_features(&self) -> Option<NodeFeatures> {
741 Self::Clear { features, .. } => features.as_ref().map(|f| f.to_context()),
742 Self::Blinded { features, .. } => features.as_ref().map(|f| f.to_context()),
745 fn supports_basic_mpp(&self) -> bool {
747 Self::Clear { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
748 Self::Blinded { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
751 fn features(&self) -> Option<FeaturesRef> {
753 Self::Clear { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt11(f)),
754 Self::Blinded { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt12(f)),
757 fn final_cltv_expiry_delta(&self) -> Option<u32> {
759 Self::Clear { final_cltv_expiry_delta, .. } => Some(*final_cltv_expiry_delta),
765 enum FeaturesRef<'a> {
766 Bolt11(&'a InvoiceFeatures),
767 Bolt12(&'a Bolt12InvoiceFeatures),
770 Bolt11(InvoiceFeatures),
771 Bolt12(Bolt12InvoiceFeatures),
775 fn bolt12(self) -> Option<Bolt12InvoiceFeatures> {
777 Self::Bolt12(f) => Some(f),
781 fn bolt11(self) -> Option<InvoiceFeatures> {
783 Self::Bolt11(f) => Some(f),
789 impl<'a> Writeable for FeaturesRef<'a> {
790 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
792 Self::Bolt11(f) => Ok(f.write(w)?),
793 Self::Bolt12(f) => Ok(f.write(w)?),
798 impl ReadableArgs<bool> for Features {
799 fn read<R: io::Read>(reader: &mut R, bolt11: bool) -> Result<Self, DecodeError> {
800 if bolt11 { return Ok(Self::Bolt11(Readable::read(reader)?)) }
801 Ok(Self::Bolt12(Readable::read(reader)?))
805 /// A list of hops along a payment path terminating with a channel to the recipient.
806 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
807 pub struct RouteHint(pub Vec<RouteHintHop>);
809 impl Writeable for RouteHint {
810 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
811 (self.0.len() as u64).write(writer)?;
812 for hop in self.0.iter() {
819 impl Readable for RouteHint {
820 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
821 let hop_count: u64 = Readable::read(reader)?;
822 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
823 for _ in 0..hop_count {
824 hops.push(Readable::read(reader)?);
830 /// A channel descriptor for a hop along a payment path.
831 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
832 pub struct RouteHintHop {
833 /// The node_id of the non-target end of the route
834 pub src_node_id: PublicKey,
835 /// The short_channel_id of this channel
836 pub short_channel_id: u64,
837 /// The fees which must be paid to use this channel
838 pub fees: RoutingFees,
839 /// The difference in CLTV values between this node and the next node.
840 pub cltv_expiry_delta: u16,
841 /// The minimum value, in msat, which must be relayed to the next hop.
842 pub htlc_minimum_msat: Option<u64>,
843 /// The maximum value in msat available for routing with a single HTLC.
844 pub htlc_maximum_msat: Option<u64>,
847 impl_writeable_tlv_based!(RouteHintHop, {
848 (0, src_node_id, required),
849 (1, htlc_minimum_msat, option),
850 (2, short_channel_id, required),
851 (3, htlc_maximum_msat, option),
853 (6, cltv_expiry_delta, required),
856 #[derive(Eq, PartialEq)]
857 struct RouteGraphNode {
859 lowest_fee_to_node: u64,
860 total_cltv_delta: u32,
861 // The maximum value a yet-to-be-constructed payment path might flow through this node.
862 // This value is upper-bounded by us by:
863 // - how much is needed for a path being constructed
864 // - how much value can channels following this node (up to the destination) can contribute,
865 // considering their capacity and fees
866 value_contribution_msat: u64,
867 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
868 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
869 path_htlc_minimum_msat: u64,
870 /// All penalties incurred from this hop on the way to the destination, as calculated using
872 path_penalty_msat: u64,
873 /// The number of hops walked up to this node.
874 path_length_to_node: u8,
877 impl cmp::Ord for RouteGraphNode {
878 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
879 let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat)
880 .saturating_add(other.path_penalty_msat);
881 let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat)
882 .saturating_add(self.path_penalty_msat);
883 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
887 impl cmp::PartialOrd for RouteGraphNode {
888 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
889 Some(self.cmp(other))
893 /// A wrapper around the various hop representations.
895 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
896 #[derive(Clone, Debug)]
897 enum CandidateRouteHop<'a> {
898 /// A hop from the payer, where the outbound liquidity is known.
900 details: &'a ChannelDetails,
902 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
904 info: DirectedChannelInfo<'a>,
905 short_channel_id: u64,
907 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
909 hint: &'a RouteHintHop,
913 impl<'a> CandidateRouteHop<'a> {
914 fn short_channel_id(&self) -> u64 {
916 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
917 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
918 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
922 // NOTE: This may alloc memory so avoid calling it in a hot code path.
923 fn features(&self) -> ChannelFeatures {
925 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
926 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
927 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
931 fn cltv_expiry_delta(&self) -> u32 {
933 CandidateRouteHop::FirstHop { .. } => 0,
934 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
935 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
939 fn htlc_minimum_msat(&self) -> u64 {
941 CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat,
942 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
943 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
947 fn fees(&self) -> RoutingFees {
949 CandidateRouteHop::FirstHop { .. } => RoutingFees {
950 base_msat: 0, proportional_millionths: 0,
952 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
953 CandidateRouteHop::PrivateHop { hint } => hint.fees,
957 fn effective_capacity(&self) -> EffectiveCapacity {
959 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
960 liquidity_msat: details.next_outbound_htlc_limit_msat,
962 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
963 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
964 EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
965 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
966 EffectiveCapacity::Infinite,
972 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
973 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
975 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
976 EffectiveCapacity::Infinite => u64::max_value(),
977 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
978 EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
979 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
980 // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
981 // expected to have been generated from up-to-date capacity information.
982 EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
983 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
984 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
988 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
989 -> bool where I1::Item: PartialEq<I2::Item> {
991 let a = iter_a.next();
992 let b = iter_b.next();
993 if a.is_none() && b.is_none() { return true; }
994 if a.is_none() || b.is_none() { return false; }
995 if a.unwrap().ne(&b.unwrap()) { return false; }
999 /// It's useful to keep track of the hops associated with the fees required to use them,
1000 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
1001 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
1002 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
1004 struct PathBuildingHop<'a> {
1005 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
1006 // is a larger refactor and will require careful performance analysis.
1008 candidate: CandidateRouteHop<'a>,
1011 /// All the fees paid *after* this channel on the way to the destination
1012 next_hops_fee_msat: u64,
1013 /// Fee paid for the use of the current channel (see candidate.fees()).
1014 /// The value will be actually deducted from the counterparty balance on the previous link.
1015 hop_use_fee_msat: u64,
1016 /// Used to compare channels when choosing the for routing.
1017 /// Includes paying for the use of a hop and the following hops, as well as
1018 /// an estimated cost of reaching this hop.
1019 /// Might get stale when fees are recomputed. Primarily for internal use.
1020 total_fee_msat: u64,
1021 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
1022 /// walk and may be invalid thereafter.
1023 path_htlc_minimum_msat: u64,
1024 /// All penalties incurred from this channel on the way to the destination, as calculated using
1025 /// channel scoring.
1026 path_penalty_msat: u64,
1027 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
1028 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
1029 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
1030 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
1031 /// avoid processing them again.
1032 was_processed: bool,
1033 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1034 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
1035 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
1036 // value_contribution_msat, which requires tracking it here. See comments below where it is
1037 // used for more info.
1038 value_contribution_msat: u64,
1041 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
1042 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1043 let mut debug_struct = f.debug_struct("PathBuildingHop");
1045 .field("node_id", &self.node_id)
1046 .field("short_channel_id", &self.candidate.short_channel_id())
1047 .field("total_fee_msat", &self.total_fee_msat)
1048 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
1049 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
1050 .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)))
1051 .field("path_penalty_msat", &self.path_penalty_msat)
1052 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
1053 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
1054 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1055 let debug_struct = debug_struct
1056 .field("value_contribution_msat", &self.value_contribution_msat);
1057 debug_struct.finish()
1061 // Instantiated with a list of hops with correct data in them collected during path finding,
1062 // an instance of this struct should be further modified only via given methods.
1064 struct PaymentPath<'a> {
1065 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
1068 impl<'a> PaymentPath<'a> {
1069 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
1070 fn get_value_msat(&self) -> u64 {
1071 self.hops.last().unwrap().0.fee_msat
1074 fn get_path_penalty_msat(&self) -> u64 {
1075 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
1078 fn get_total_fee_paid_msat(&self) -> u64 {
1079 if self.hops.len() < 1 {
1083 // Can't use next_hops_fee_msat because it gets outdated.
1084 for (i, (hop, _)) in self.hops.iter().enumerate() {
1085 if i != self.hops.len() - 1 {
1086 result += hop.fee_msat;
1092 fn get_cost_msat(&self) -> u64 {
1093 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
1096 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
1097 // to change fees may result in an inconsistency.
1099 // Sometimes we call this function right after constructing a path which is inconsistent in
1100 // that it the value being transferred has decreased while we were doing path finding, leading
1101 // to the fees being paid not lining up with the actual limits.
1103 // Note that this function is not aware of the available_liquidity limit, and thus does not
1104 // support increasing the value being transferred beyond what was selected during the initial
1106 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
1107 let mut total_fee_paid_msat = 0 as u64;
1108 for i in (0..self.hops.len()).rev() {
1109 let last_hop = i == self.hops.len() - 1;
1111 // For non-last-hop, this value will represent the fees paid on the current hop. It
1112 // will consist of the fees for the use of the next hop, and extra fees to match
1113 // htlc_minimum_msat of the current channel. Last hop is handled separately.
1114 let mut cur_hop_fees_msat = 0;
1116 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
1119 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
1120 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
1121 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
1122 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
1123 // set it too high just to maliciously take more fees by exploiting this
1124 // match htlc_minimum_msat logic.
1125 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
1126 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
1127 // Note that there is a risk that *previous hops* (those closer to us, as we go
1128 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
1130 // This might make us end up with a broken route, although this should be super-rare
1131 // in practice, both because of how healthy channels look like, and how we pick
1132 // channels in add_entry.
1133 // Also, this can't be exploited more heavily than *announce a free path and fail
1135 cur_hop_transferred_amount_msat += extra_fees_msat;
1136 total_fee_paid_msat += extra_fees_msat;
1137 cur_hop_fees_msat += extra_fees_msat;
1141 // Final hop is a special case: it usually has just value_msat (by design), but also
1142 // it still could overpay for the htlc_minimum_msat.
1143 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
1145 // Propagate updated fees for the use of the channels to one hop back, where they
1146 // will be actually paid (fee_msat). The last hop is handled above separately.
1147 cur_hop.fee_msat = cur_hop_fees_msat;
1150 // Fee for the use of the current hop which will be deducted on the previous hop.
1151 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
1152 // this channel is free for us.
1154 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
1155 cur_hop.hop_use_fee_msat = new_fee;
1156 total_fee_paid_msat += new_fee;
1158 // It should not be possible because this function is called only to reduce the
1159 // value. In that case, compute_fee was already called with the same fees for
1160 // larger amount and there was no overflow.
1169 /// Calculate the fees required to route the given amount over a channel with the given fees.
1170 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
1171 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1172 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
1176 /// Calculate the fees required to route the given amount over a channel with the given fees,
1177 /// saturating to [`u64::max_value`].
1178 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
1179 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1180 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
1181 .saturating_add(channel_fees.base_msat as u64)
1184 /// The default `features` we assume for a node in a route, when no `features` are known about that
1187 /// Default features are:
1188 /// * variable_length_onion_optional
1189 fn default_node_features() -> NodeFeatures {
1190 let mut features = NodeFeatures::empty();
1191 features.set_variable_length_onion_optional();
1195 struct LoggedPayeePubkey(Option<PublicKey>);
1196 impl fmt::Display for LoggedPayeePubkey {
1197 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1200 "payee node id ".fmt(f)?;
1204 "blinded payee".fmt(f)
1211 fn sort_first_hop_channels(
1212 channels: &mut Vec<&ChannelDetails>, used_channel_liquidities: &HashMap<(u64, bool), u64>,
1213 recommended_value_msat: u64, our_node_pubkey: &PublicKey
1215 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1216 // most like to use.
1218 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1219 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1222 // Second, because simply always sorting in descending order would always use our largest
1223 // available outbound capacity, needlessly fragmenting our available channel capacities,
1224 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1225 // which have enough, but not too much, capacity for the payment.
1227 // Available outbound balances factor in liquidity already reserved for previously found paths.
1228 channels.sort_unstable_by(|chan_a, chan_b| {
1229 let chan_a_outbound_limit_msat = chan_a.next_outbound_htlc_limit_msat
1230 .saturating_sub(*used_channel_liquidities.get(&(chan_a.get_outbound_payment_scid().unwrap(),
1231 our_node_pubkey < &chan_a.counterparty.node_id)).unwrap_or(&0));
1232 let chan_b_outbound_limit_msat = chan_b.next_outbound_htlc_limit_msat
1233 .saturating_sub(*used_channel_liquidities.get(&(chan_b.get_outbound_payment_scid().unwrap(),
1234 our_node_pubkey < &chan_b.counterparty.node_id)).unwrap_or(&0));
1235 if chan_b_outbound_limit_msat < recommended_value_msat || chan_a_outbound_limit_msat < recommended_value_msat {
1236 // Sort in descending order
1237 chan_b_outbound_limit_msat.cmp(&chan_a_outbound_limit_msat)
1239 // Sort in ascending order
1240 chan_a_outbound_limit_msat.cmp(&chan_b_outbound_limit_msat)
1245 /// Finds a route from us (payer) to the given target node (payee).
1247 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
1248 /// Without this, MPP will only be used if the payee's features are available in the network graph.
1250 /// Private routing paths between a public node and the target may be included in `params.payee`.
1252 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
1253 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
1254 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
1256 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1257 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1258 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1262 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
1263 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
1268 /// Panics if first_hops contains channels without short_channel_ids;
1269 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1271 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1272 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1273 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1274 pub fn find_route<L: Deref, GL: Deref, S: Score>(
1275 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1276 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1277 scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
1278 ) -> Result<Route, LightningError>
1279 where L::Target: Logger, GL::Target: Logger {
1280 let graph_lock = network_graph.read_only();
1281 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
1282 route_params.final_value_msat, logger, scorer, score_params,
1283 random_seed_bytes)?;
1284 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1288 pub(crate) fn get_route<L: Deref, S: Score>(
1289 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
1290 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, logger: L, scorer: &S, score_params: &S::ScoreParams,
1291 _random_seed_bytes: &[u8; 32]
1292 ) -> Result<Route, LightningError>
1293 where L::Target: Logger {
1294 // If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
1295 // unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
1296 // so use a dummy id for this in the blinded case.
1297 let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
1298 const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [42u8; 33];
1299 let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
1300 let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
1301 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1303 if payee_node_id_opt.map_or(false, |payee| payee == our_node_id) {
1304 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1307 if final_value_msat > MAX_VALUE_MSAT {
1308 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1311 if final_value_msat == 0 {
1312 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1315 match &payment_params.payee {
1316 Payee::Clear { route_hints, node_id, .. } => {
1317 for route in route_hints.iter() {
1318 for hop in &route.0 {
1319 if hop.src_node_id == *node_id {
1320 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1325 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1328 let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
1329 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1330 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});
1333 // The general routing idea is the following:
1334 // 1. Fill first/last hops communicated by the caller.
1335 // 2. Attempt to construct a path from payer to payee for transferring
1336 // any ~sufficient (described later) value.
1337 // If succeed, remember which channels were used and how much liquidity they have available,
1338 // so that future paths don't rely on the same liquidity.
1339 // 3. Proceed to the next step if:
1340 // - we hit the recommended target value;
1341 // - OR if we could not construct a new path. Any next attempt will fail too.
1342 // Otherwise, repeat step 2.
1343 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1344 // (not recommended value).
1345 // 5. If yes, proceed. If not, fail routing.
1346 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1347 // transferred up to the transfer target value.
1348 // 7. Reduce the value of the last path until we are sending only the target value.
1349 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1350 // them so that we're not sending two HTLCs along the same path.
1352 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1353 // distance from the payee
1355 // We are not a faithful Dijkstra's implementation because we can change values which impact
1356 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1357 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1358 // the value we are currently attempting to send over a path, we simply reduce the value being
1359 // sent along the path for any hops after that channel. This may imply that later fees (which
1360 // we've already tabulated) are lower because a smaller value is passing through the channels
1361 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1362 // channels which were selected earlier (and which may still be used for other paths without a
1363 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1366 // One potentially problematic case for this algorithm would be if there are many
1367 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1368 // graph walking), we may never find a path which is not liquidity-limited and has lower
1369 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1370 // Because we only consider paths with at least 5% of the total value being sent, the damage
1371 // from such a case should be limited, however this could be further reduced in the future by
1372 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1373 // limits for the purposes of fee calculation.
1375 // Alternatively, we could store more detailed path information in the heap (targets, below)
1376 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1377 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1378 // and practically (as we would need to store dynamically-allocated path information in heap
1379 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
1380 // results of such an algorithm would likely be biased towards lower-value paths.
1382 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
1383 // outside of our current search value, running a path search more times to gather candidate
1384 // paths at different values. While this may be acceptable, further path searches may increase
1385 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
1386 // graph for candidate paths, calculating the maximum value which can realistically be sent at
1387 // the same time, remaining generic across different payment values.
1389 let network_channels = network_graph.channels();
1390 let network_nodes = network_graph.nodes();
1392 if payment_params.max_path_count == 0 {
1393 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
1396 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
1397 // it. If the payee supports it they're supposed to include it in the invoice, so that should
1399 let allow_mpp = if payment_params.max_path_count == 1 {
1401 } else if payment_params.payee.supports_basic_mpp() {
1403 } else if let Some(payee) = payee_node_id_opt {
1404 network_nodes.get(&payee).map_or(false, |node| node.announcement_info.as_ref().map_or(false,
1405 |info| info.features.supports_basic_mpp()))
1408 log_trace!(logger, "Searching for a route from payer {} to {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
1409 LoggedPayeePubkey(payment_params.payee.node_id()), if allow_mpp { "with" } else { "without" },
1410 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
1413 // Prepare the data we'll use for payee-to-payer search by
1414 // inserting first hops suggested by the caller as targets.
1415 // Our search will then attempt to reach them while traversing from the payee node.
1416 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
1417 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
1418 if let Some(hops) = first_hops {
1420 if chan.get_outbound_payment_scid().is_none() {
1421 panic!("first_hops should be filled in with usable channels, not pending ones");
1423 if chan.counterparty.node_id == *our_node_pubkey {
1424 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
1427 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
1428 .or_insert(Vec::new())
1431 if first_hop_targets.is_empty() {
1432 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
1436 // The main heap containing all candidate next-hops sorted by their score (max(fee,
1437 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
1438 // adding duplicate entries when we find a better path to a given node.
1439 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
1441 // Map from node_id to information about the best current path to that node, including feerate
1443 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
1445 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
1446 // indicating that we may wish to try again with a higher value, potentially paying to meet an
1447 // htlc_minimum with extra fees while still finding a cheaper path.
1448 let mut hit_minimum_limit;
1450 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
1451 // We start with a path_value of the exact amount we want, and if that generates a route we may
1452 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
1453 // amount we want in total across paths, selecting the best subset at the end.
1454 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
1455 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
1456 let mut path_value_msat = final_value_msat;
1458 // Routing Fragmentation Mitigation heuristic:
1460 // Routing fragmentation across many payment paths increases the overall routing
1461 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
1462 // Taking too many smaller paths also increases the chance of payment failure.
1463 // Thus to avoid this effect, we require from our collected links to provide
1464 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
1465 // This requirement is currently set to be 1/max_path_count of the payment
1466 // value to ensure we only ever return routes that do not violate this limit.
1467 let minimal_value_contribution_msat: u64 = if allow_mpp {
1468 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
1473 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
1474 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
1475 // drop the requirement by setting this to 0.
1476 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
1478 // Keep track of how much liquidity has been used in selected channels. Used to determine
1479 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
1480 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
1481 // liquidity used in one direction will not offset any used in the opposite direction.
1482 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
1483 HashMap::with_capacity(network_nodes.len());
1485 // Keeping track of how much value we already collected across other paths. Helps to decide
1486 // when we want to stop looking for new paths.
1487 let mut already_collected_value_msat = 0;
1489 for (_, channels) in first_hop_targets.iter_mut() {
1490 sort_first_hop_channels(channels, &used_channel_liquidities, recommended_value_msat,
1494 log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
1495 LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
1497 macro_rules! add_entry {
1498 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
1499 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
1500 // since that value has to be transferred over this channel.
1501 // Returns whether this channel caused an update to `targets`.
1502 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
1503 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
1504 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
1505 // We "return" whether we updated the path at the end, and how much we can route via
1506 // this channel, via this:
1507 let mut did_add_update_path_to_src_node = None;
1508 // Channels to self should not be used. This is more of belt-and-suspenders, because in
1509 // practice these cases should be caught earlier:
1510 // - for regular channels at channel announcement (TODO)
1511 // - for first and last hops early in get_route
1512 if $src_node_id != $dest_node_id {
1513 let short_channel_id = $candidate.short_channel_id();
1514 let effective_capacity = $candidate.effective_capacity();
1515 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
1517 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
1518 // It may be misleading because we might later choose to reduce the value transferred
1519 // over these channels, and the channel which was insufficient might become sufficient.
1520 // Worst case: we drop a good channel here because it can't cover the high following
1521 // fees caused by one expensive channel, but then this channel could have been used
1522 // if the amount being transferred over this path is lower.
1523 // We do this for now, but this is a subject for removal.
1524 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
1525 let used_liquidity_msat = used_channel_liquidities
1526 .get(&(short_channel_id, $src_node_id < $dest_node_id))
1527 .map_or(0, |used_liquidity_msat| {
1528 available_value_contribution_msat = available_value_contribution_msat
1529 .saturating_sub(*used_liquidity_msat);
1530 *used_liquidity_msat
1533 // Verify the liquidity offered by this channel complies to the minimal contribution.
1534 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
1535 // Do not consider candidate hops that would exceed the maximum path length.
1536 let path_length_to_node = $next_hops_path_length + 1;
1537 let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
1539 // Do not consider candidates that exceed the maximum total cltv expiry limit.
1540 // In order to already account for some of the privacy enhancing random CLTV
1541 // expiry delta offset we add on top later, we subtract a rough estimate
1542 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
1543 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
1544 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
1545 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
1546 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
1547 .saturating_add($candidate.cltv_expiry_delta());
1548 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
1550 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
1551 // Includes paying fees for the use of the following channels.
1552 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
1553 Some(result) => result,
1554 // Can't overflow due to how the values were computed right above.
1555 None => unreachable!(),
1557 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1558 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
1559 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
1561 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1562 let may_overpay_to_meet_path_minimum_msat =
1563 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
1564 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
1565 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
1566 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
1568 let payment_failed_on_this_channel =
1569 payment_params.previously_failed_channels.contains(&short_channel_id);
1571 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
1572 // bother considering this channel. If retrying with recommended_value_msat may
1573 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
1574 // around again with a higher amount.
1575 if !contributes_sufficient_value || exceeds_max_path_length ||
1576 exceeds_cltv_delta_limit || payment_failed_on_this_channel {
1577 // Path isn't useful, ignore it and move on.
1578 } else if may_overpay_to_meet_path_minimum_msat {
1579 hit_minimum_limit = true;
1580 } else if over_path_minimum_msat {
1581 // Note that low contribution here (limited by available_liquidity_msat)
1582 // might violate htlc_minimum_msat on the hops which are next along the
1583 // payment path (upstream to the payee). To avoid that, we recompute
1584 // path fees knowing the final path contribution after constructing it.
1585 let path_htlc_minimum_msat = cmp::max(
1586 compute_fees_saturating($next_hops_path_htlc_minimum_msat, $candidate.fees())
1587 .saturating_add($next_hops_path_htlc_minimum_msat),
1588 $candidate.htlc_minimum_msat());
1589 let hm_entry = dist.entry($src_node_id);
1590 let old_entry = hm_entry.or_insert_with(|| {
1591 // If there was previously no known way to access the source node
1592 // (recall it goes payee-to-payer) of short_channel_id, first add a
1593 // semi-dummy record just to compute the fees to reach the source node.
1594 // This will affect our decision on selecting short_channel_id
1595 // as a way to reach the $dest_node_id.
1597 node_id: $dest_node_id.clone(),
1598 candidate: $candidate.clone(),
1600 next_hops_fee_msat: u64::max_value(),
1601 hop_use_fee_msat: u64::max_value(),
1602 total_fee_msat: u64::max_value(),
1603 path_htlc_minimum_msat,
1604 path_penalty_msat: u64::max_value(),
1605 was_processed: false,
1606 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1607 value_contribution_msat,
1611 #[allow(unused_mut)] // We only use the mut in cfg(test)
1612 let mut should_process = !old_entry.was_processed;
1613 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1615 // In test/fuzzing builds, we do extra checks to make sure the skipping
1616 // of already-seen nodes only happens in cases we expect (see below).
1617 if !should_process { should_process = true; }
1621 let mut hop_use_fee_msat = 0;
1622 let mut total_fee_msat: u64 = $next_hops_fee_msat;
1624 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1625 // will have the same effective-fee
1626 if $src_node_id != our_node_id {
1627 // Note that `u64::max_value` means we'll always fail the
1628 // `old_entry.total_fee_msat > total_fee_msat` check below
1629 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
1630 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
1633 let channel_usage = ChannelUsage {
1634 amount_msat: amount_to_transfer_over_msat,
1635 inflight_htlc_msat: used_liquidity_msat,
1638 let channel_penalty_msat = scorer.channel_penalty_msat(
1639 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage, score_params
1641 let path_penalty_msat = $next_hops_path_penalty_msat
1642 .saturating_add(channel_penalty_msat);
1643 let new_graph_node = RouteGraphNode {
1644 node_id: $src_node_id,
1645 lowest_fee_to_node: total_fee_msat,
1646 total_cltv_delta: hop_total_cltv_delta,
1647 value_contribution_msat,
1648 path_htlc_minimum_msat,
1650 path_length_to_node,
1653 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1654 // if this way is cheaper than the already known
1655 // (considering the cost to "reach" this channel from the route destination,
1656 // the cost of using this channel,
1657 // and the cost of routing to the source node of this channel).
1658 // Also, consider that htlc_minimum_msat_difference, because we might end up
1659 // paying it. Consider the following exploit:
1660 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1661 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1662 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1663 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1665 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1666 // but it may require additional tracking - we don't want to double-count
1667 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1668 // can't use something that may decrease on future hops.
1669 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1670 .saturating_add(old_entry.path_penalty_msat);
1671 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1672 .saturating_add(path_penalty_msat);
1674 if !old_entry.was_processed && new_cost < old_cost {
1675 targets.push(new_graph_node);
1676 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1677 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1678 old_entry.total_fee_msat = total_fee_msat;
1679 old_entry.node_id = $dest_node_id.clone();
1680 old_entry.candidate = $candidate.clone();
1681 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1682 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1683 old_entry.path_penalty_msat = path_penalty_msat;
1684 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1686 old_entry.value_contribution_msat = value_contribution_msat;
1688 did_add_update_path_to_src_node = Some(value_contribution_msat);
1689 } else if old_entry.was_processed && new_cost < old_cost {
1690 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1692 // If we're skipping processing a node which was previously
1693 // processed even though we found another path to it with a
1694 // cheaper fee, check that it was because the second path we
1695 // found (which we are processing now) has a lower value
1696 // contribution due to an HTLC minimum limit.
1698 // e.g. take a graph with two paths from node 1 to node 2, one
1699 // through channel A, and one through channel B. Channel A and
1700 // B are both in the to-process heap, with their scores set by
1701 // a higher htlc_minimum than fee.
1702 // Channel A is processed first, and the channels onwards from
1703 // node 1 are added to the to-process heap. Thereafter, we pop
1704 // Channel B off of the heap, note that it has a much more
1705 // restrictive htlc_maximum_msat, and recalculate the fees for
1706 // all of node 1's channels using the new, reduced, amount.
1708 // This would be bogus - we'd be selecting a higher-fee path
1709 // with a lower htlc_maximum_msat instead of the one we'd
1710 // already decided to use.
1711 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1713 value_contribution_msat + path_penalty_msat <
1714 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1722 did_add_update_path_to_src_node
1726 let default_node_features = default_node_features();
1728 // Find ways (channels with destination) to reach a given node and store them
1729 // in the corresponding data structures (routing graph etc).
1730 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1731 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1732 // This data can later be helpful to optimize routing (pay lower fees).
1733 macro_rules! add_entries_to_cheapest_to_target_node {
1734 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1735 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1736 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1737 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1738 let was_processed = elem.was_processed;
1739 elem.was_processed = true;
1742 // Entries are added to dist in add_entry!() when there is a channel from a node.
1743 // Because there are no channels from payee, it will not have a dist entry at this point.
1744 // If we're processing any other node, it is always be the result of a channel from it.
1745 debug_assert_eq!($node_id, maybe_dummy_payee_node_id);
1750 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1751 for details in first_channels {
1752 let candidate = CandidateRouteHop::FirstHop { details };
1753 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1754 $next_hops_value_contribution,
1755 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1756 $next_hops_cltv_delta, $next_hops_path_length);
1760 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1763 &default_node_features
1766 if !features.requires_unknown_bits() {
1767 for chan_id in $node.channels.iter() {
1768 let chan = network_channels.get(chan_id).unwrap();
1769 if !chan.features.requires_unknown_bits() {
1770 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
1771 if first_hops.is_none() || *source != our_node_id {
1772 if directed_channel.direction().enabled {
1773 let candidate = CandidateRouteHop::PublicHop {
1774 info: directed_channel,
1775 short_channel_id: *chan_id,
1777 add_entry!(candidate, *source, $node_id,
1778 $fee_to_target_msat,
1779 $next_hops_value_contribution,
1780 $next_hops_path_htlc_minimum_msat,
1781 $next_hops_path_penalty_msat,
1782 $next_hops_cltv_delta, $next_hops_path_length);
1793 let mut payment_paths = Vec::<PaymentPath>::new();
1795 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1796 'paths_collection: loop {
1797 // For every new path, start from scratch, except for used_channel_liquidities, which
1798 // helps to avoid reusing previously selected paths in future iterations.
1801 hit_minimum_limit = false;
1803 // If first hop is a private channel and the only way to reach the payee, this is the only
1804 // place where it could be added.
1805 payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| {
1806 for details in first_channels {
1807 let candidate = CandidateRouteHop::FirstHop { details };
1808 let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
1809 0, 0u64, 0, 0).is_some();
1810 log_trace!(logger, "{} direct route to payee via SCID {}",
1811 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1815 // Add the payee as a target, so that the payee-to-payer
1816 // search algorithm knows what to start with.
1817 payee_node_id_opt.map(|payee| match network_nodes.get(&payee) {
1818 // The payee is not in our network graph, so nothing to add here.
1819 // There is still a chance of reaching them via last_hops though,
1820 // so don't yet fail the payment here.
1821 // If not, targets.pop() will not even let us enter the loop in step 2.
1824 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0, 0u64, 0, 0);
1829 // If a caller provided us with last hops, add them to routing targets. Since this happens
1830 // earlier than general path finding, they will be somewhat prioritized, although currently
1831 // it matters only if the fees are exactly the same.
1832 let route_hints = match &payment_params.payee {
1833 Payee::Clear { route_hints, .. } => route_hints,
1834 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1836 for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
1837 let first_hop_in_route = &(route.0)[0];
1838 let have_hop_src_in_graph =
1839 // Only add the hops in this route to our candidate set if either
1840 // we have a direct channel to the first hop or the first hop is
1841 // in the regular network graph.
1842 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1843 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1844 if have_hop_src_in_graph {
1845 // We start building the path from reverse, i.e., from payee
1846 // to the first RouteHintHop in the path.
1847 let hop_iter = route.0.iter().rev();
1848 let prev_hop_iter = core::iter::once(&maybe_dummy_payee_pk).chain(
1849 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1850 let mut hop_used = true;
1851 let mut aggregate_next_hops_fee_msat: u64 = 0;
1852 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1853 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1854 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1855 let mut aggregate_next_hops_path_length: u8 = 0;
1856 let mut aggregate_path_contribution_msat = path_value_msat;
1858 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1859 let source = NodeId::from_pubkey(&hop.src_node_id);
1860 let target = NodeId::from_pubkey(&prev_hop_id);
1861 let candidate = network_channels
1862 .get(&hop.short_channel_id)
1863 .and_then(|channel| channel.as_directed_to(&target))
1864 .map(|(info, _)| CandidateRouteHop::PublicHop {
1866 short_channel_id: hop.short_channel_id,
1868 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1870 if let Some(hop_used_msat) = add_entry!(candidate, source, target,
1871 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
1872 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
1873 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
1875 aggregate_path_contribution_msat = hop_used_msat;
1877 // If this hop was not used then there is no use checking the preceding
1878 // hops in the RouteHint. We can break by just searching for a direct
1879 // channel between last checked hop and first_hop_targets.
1883 let used_liquidity_msat = used_channel_liquidities
1884 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1885 let channel_usage = ChannelUsage {
1886 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1887 inflight_htlc_msat: used_liquidity_msat,
1888 effective_capacity: candidate.effective_capacity(),
1890 let channel_penalty_msat = scorer.channel_penalty_msat(
1891 hop.short_channel_id, &source, &target, channel_usage, score_params
1893 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1894 .saturating_add(channel_penalty_msat);
1896 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1897 .saturating_add(hop.cltv_expiry_delta as u32);
1899 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1902 // Searching for a direct channel between last checked hop and first_hop_targets
1903 if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&prev_hop_id)) {
1904 sort_first_hop_channels(first_channels, &used_channel_liquidities,
1905 recommended_value_msat, our_node_pubkey);
1906 for details in first_channels {
1907 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
1908 add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1909 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
1910 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
1911 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
1919 // In the next values of the iterator, the aggregate fees already reflects
1920 // the sum of value sent from payer (final_value_msat) and routing fees
1921 // for the last node in the RouteHint. We need to just add the fees to
1922 // route through the current node so that the preceding node (next iteration)
1924 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1925 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1926 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1928 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1929 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1930 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1931 .checked_add(hop_htlc_minimum_msat_inc);
1932 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1934 if idx == route.0.len() - 1 {
1935 // The last hop in this iterator is the first hop in
1936 // overall RouteHint.
1937 // If this hop connects to a node with which we have a direct channel,
1938 // ignore the network graph and, if the last hop was added, add our
1939 // direct channel to the candidate set.
1941 // Note that we *must* check if the last hop was added as `add_entry`
1942 // always assumes that the third argument is a node to which we have a
1944 if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hop.src_node_id)) {
1945 sort_first_hop_channels(first_channels, &used_channel_liquidities,
1946 recommended_value_msat, our_node_pubkey);
1947 for details in first_channels {
1948 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
1949 add_entry!(first_hop_candidate, our_node_id,
1950 NodeId::from_pubkey(&hop.src_node_id),
1951 aggregate_next_hops_fee_msat,
1952 aggregate_path_contribution_msat,
1953 aggregate_next_hops_path_htlc_minimum_msat,
1954 aggregate_next_hops_path_penalty_msat,
1955 aggregate_next_hops_cltv_delta,
1956 aggregate_next_hops_path_length);
1964 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1966 // At this point, targets are filled with the data from first and
1967 // last hops communicated by the caller, and the payment receiver.
1968 let mut found_new_path = false;
1971 // If this loop terminates due the exhaustion of targets, two situations are possible:
1972 // - not enough outgoing liquidity:
1973 // 0 < already_collected_value_msat < final_value_msat
1974 // - enough outgoing liquidity:
1975 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1976 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1977 // paths_collection will be stopped because found_new_path==false.
1978 // This is not necessarily a routing failure.
1979 'path_construction: while let Some(RouteGraphNode { node_id, lowest_fee_to_node, total_cltv_delta, mut value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, path_length_to_node, .. }) = targets.pop() {
1981 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1982 // traversing the graph and arrange the path out of what we found.
1983 if node_id == our_node_id {
1984 let mut new_entry = dist.remove(&our_node_id).unwrap();
1985 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1988 let mut features_set = false;
1989 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1990 for details in first_channels {
1991 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1992 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1993 features_set = true;
1999 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
2000 if let Some(node_info) = node.announcement_info.as_ref() {
2001 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
2003 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
2006 // We can fill in features for everything except hops which were
2007 // provided via the invoice we're paying. We could guess based on the
2008 // recipient's features but for now we simply avoid guessing at all.
2012 // Means we succesfully traversed from the payer to the payee, now
2013 // save this path for the payment route. Also, update the liquidity
2014 // remaining on the used hops, so that we take them into account
2015 // while looking for more paths.
2016 if ordered_hops.last().unwrap().0.node_id == maybe_dummy_payee_node_id {
2020 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
2021 Some(payment_hop) => payment_hop,
2022 // We can't arrive at None because, if we ever add an entry to targets,
2023 // we also fill in the entry in dist (see add_entry!).
2024 None => unreachable!(),
2026 // We "propagate" the fees one hop backward (topologically) here,
2027 // so that fees paid for a HTLC forwarding on the current channel are
2028 // associated with the previous channel (where they will be subtracted).
2029 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
2030 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
2032 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
2033 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
2035 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
2036 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
2038 let mut payment_path = PaymentPath {hops: ordered_hops};
2040 // We could have possibly constructed a slightly inconsistent path: since we reduce
2041 // value being transferred along the way, we could have violated htlc_minimum_msat
2042 // on some channels we already passed (assuming dest->source direction). Here, we
2043 // recompute the fees again, so that if that's the case, we match the currently
2044 // underpaid htlc_minimum_msat with fees.
2045 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
2046 value_contribution_msat = cmp::min(value_contribution_msat, final_value_msat);
2047 payment_path.update_value_and_recompute_fees(value_contribution_msat);
2049 // Since a path allows to transfer as much value as
2050 // the smallest channel it has ("bottleneck"), we should recompute
2051 // the fees so sender HTLC don't overpay fees when traversing
2052 // larger channels than the bottleneck. This may happen because
2053 // when we were selecting those channels we were not aware how much value
2054 // this path will transfer, and the relative fee for them
2055 // might have been computed considering a larger value.
2056 // Remember that we used these channels so that we don't rely
2057 // on the same liquidity in future paths.
2058 let mut prevented_redundant_path_selection = false;
2059 let prev_hop_iter = core::iter::once(&our_node_id)
2060 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
2061 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
2062 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
2063 let used_liquidity_msat = used_channel_liquidities
2064 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
2065 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
2066 .or_insert(spent_on_hop_msat);
2067 let hop_capacity = hop.candidate.effective_capacity();
2068 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
2069 if *used_liquidity_msat == hop_max_msat {
2070 // If this path used all of this channel's available liquidity, we know
2071 // this path will not be selected again in the next loop iteration.
2072 prevented_redundant_path_selection = true;
2074 debug_assert!(*used_liquidity_msat <= hop_max_msat);
2076 if !prevented_redundant_path_selection {
2077 // If we weren't capped by hitting a liquidity limit on a channel in the path,
2078 // we'll probably end up picking the same path again on the next iteration.
2079 // Decrease the available liquidity of a hop in the middle of the path.
2080 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
2081 let exhausted = u64::max_value();
2082 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
2083 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
2084 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
2087 // Track the total amount all our collected paths allow to send so that we know
2088 // when to stop looking for more paths
2089 already_collected_value_msat += value_contribution_msat;
2091 payment_paths.push(payment_path);
2092 found_new_path = true;
2093 break 'path_construction;
2096 // If we found a path back to the payee, we shouldn't try to process it again. This is
2097 // the equivalent of the `elem.was_processed` check in
2098 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
2099 if node_id == maybe_dummy_payee_node_id { continue 'path_construction; }
2101 // Otherwise, since the current target node is not us,
2102 // keep "unrolling" the payment graph from payee to payer by
2103 // finding a way to reach the current target from the payer side.
2104 match network_nodes.get(&node_id) {
2107 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
2108 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
2109 total_cltv_delta, path_length_to_node);
2115 if !found_new_path && channel_saturation_pow_half != 0 {
2116 channel_saturation_pow_half = 0;
2117 continue 'paths_collection;
2119 // If we don't support MPP, no use trying to gather more value ever.
2120 break 'paths_collection;
2124 // Stop either when the recommended value is reached or if no new path was found in this
2126 // In the latter case, making another path finding attempt won't help,
2127 // because we deterministically terminated the search due to low liquidity.
2128 if !found_new_path && channel_saturation_pow_half != 0 {
2129 channel_saturation_pow_half = 0;
2130 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
2131 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
2132 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
2133 break 'paths_collection;
2134 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
2135 // Further, if this was our first walk of the graph, and we weren't limited by an
2136 // htlc_minimum_msat, return immediately because this path should suffice. If we were
2137 // limited by an htlc_minimum_msat value, find another path with a higher value,
2138 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
2139 // still keeping a lower total fee than this path.
2140 if !hit_minimum_limit {
2141 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
2142 break 'paths_collection;
2144 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
2145 path_value_msat = recommended_value_msat;
2150 if payment_paths.len() == 0 {
2151 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2154 if already_collected_value_msat < final_value_msat {
2155 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2159 let mut selected_route = payment_paths;
2161 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
2162 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
2164 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
2165 // the value they contribute towards the payment amount.
2166 // We sort in descending order as we will remove from the front in `retain`, next.
2167 selected_route.sort_unstable_by(|a, b|
2168 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
2169 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
2172 // We should make sure that at least 1 path left.
2173 let mut paths_left = selected_route.len();
2174 selected_route.retain(|path| {
2175 if paths_left == 1 {
2178 let path_value_msat = path.get_value_msat();
2179 if path_value_msat <= overpaid_value_msat {
2180 overpaid_value_msat -= path_value_msat;
2186 debug_assert!(selected_route.len() > 0);
2188 if overpaid_value_msat != 0 {
2190 // Now, subtract the remaining overpaid value from the most-expensive path.
2191 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
2192 // so that the sender pays less fees overall. And also htlc_minimum_msat.
2193 selected_route.sort_unstable_by(|a, b| {
2194 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2195 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2196 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
2198 let expensive_payment_path = selected_route.first_mut().unwrap();
2200 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
2201 // can't go negative.
2202 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
2203 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
2207 // Sort by the path itself and combine redundant paths.
2208 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
2209 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
2211 selected_route.sort_unstable_by_key(|path| {
2212 let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
2213 debug_assert!(path.hops.len() <= key.len());
2214 for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
2219 for idx in 0..(selected_route.len() - 1) {
2220 if idx + 1 >= selected_route.len() { break; }
2221 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
2222 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
2223 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
2224 selected_route[idx].update_value_and_recompute_fees(new_value);
2225 selected_route.remove(idx + 1);
2229 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
2230 for payment_path in selected_route {
2231 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
2233 pubkey: PublicKey::from_slice(payment_hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &payment_hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
2234 node_features: node_features.clone(),
2235 short_channel_id: payment_hop.candidate.short_channel_id(),
2236 channel_features: payment_hop.candidate.features(),
2237 fee_msat: payment_hop.fee_msat,
2238 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
2240 }).collect::<Vec<_>>();
2241 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
2242 // applicable for the previous hop.
2243 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
2244 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
2246 selected_paths.push(path);
2248 // Make sure we would never create a route with more paths than we allow.
2249 debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
2251 if let Some(node_features) = payment_params.payee.node_features() {
2252 for path in selected_paths.iter_mut() {
2253 if let Ok(route_hop) = path.last_mut().unwrap() {
2254 route_hop.node_features = node_features.clone();
2259 let mut paths: Vec<Path> = Vec::new();
2260 for results_vec in selected_paths {
2261 let mut hops = Vec::with_capacity(results_vec.len());
2262 for res in results_vec { hops.push(res?); }
2263 paths.push(Path { hops, blinded_tail: None });
2267 payment_params: Some(payment_params.clone()),
2269 log_info!(logger, "Got route: {}", log_route!(route));
2273 // When an adversarial intermediary node observes a payment, it may be able to infer its
2274 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
2275 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
2276 // payment path by adding a randomized 'shadow route' offset to the final hop.
2277 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
2278 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
2280 let network_channels = network_graph.channels();
2281 let network_nodes = network_graph.nodes();
2283 for path in route.paths.iter_mut() {
2284 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
2286 // Remember the last three nodes of the random walk and avoid looping back on them.
2287 // Init with the last three nodes from the actual path, if possible.
2288 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
2289 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(2)).unwrap().pubkey),
2290 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(3)).unwrap().pubkey)];
2292 // Choose the last publicly known node as the starting point for the random walk.
2293 let mut cur_hop: Option<NodeId> = None;
2294 let mut path_nonce = [0u8; 12];
2295 if let Some(starting_hop) = path.hops.iter().rev()
2296 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
2297 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
2298 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
2301 // Init PRNG with the path-dependant nonce, which is static for private paths.
2302 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
2303 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
2305 // Pick a random path length in [1 .. 3]
2306 prng.process_in_place(&mut random_path_bytes);
2307 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
2309 for random_hop in 0..random_walk_length {
2310 // If we don't find a suitable offset in the public network graph, we default to
2311 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2312 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
2314 if let Some(cur_node_id) = cur_hop {
2315 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
2316 // Randomly choose the next unvisited hop.
2317 prng.process_in_place(&mut random_path_bytes);
2318 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
2319 .checked_rem(cur_node.channels.len())
2320 .and_then(|index| cur_node.channels.get(index))
2321 .and_then(|id| network_channels.get(id)) {
2322 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
2323 if !nodes_to_avoid.iter().any(|x| x == next_id) {
2324 nodes_to_avoid[random_hop] = *next_id;
2325 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
2326 cur_hop = Some(*next_id);
2333 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
2334 .checked_add(random_hop_offset)
2335 .unwrap_or(shadow_ctlv_expiry_delta_offset);
2338 // Limit the total offset to reduce the worst-case locked liquidity timevalue
2339 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
2340 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
2342 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
2343 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2344 let path_total_cltv_expiry_delta: u32 = path.hops.iter().map(|h| h.cltv_expiry_delta).sum();
2345 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
2346 max_path_offset = cmp::max(
2347 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
2348 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
2349 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
2351 // Add 'shadow' CLTV offset to the final hop
2352 if let Some(tail) = path.blinded_tail.as_mut() {
2353 tail.excess_final_cltv_expiry_delta = tail.excess_final_cltv_expiry_delta
2354 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(tail.excess_final_cltv_expiry_delta);
2356 if let Some(last_hop) = path.hops.last_mut() {
2357 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
2358 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
2363 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
2364 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
2366 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
2367 pub fn build_route_from_hops<L: Deref, GL: Deref>(
2368 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
2369 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
2370 ) -> Result<Route, LightningError>
2371 where L::Target: Logger, GL::Target: Logger {
2372 let graph_lock = network_graph.read_only();
2373 let mut route = build_route_from_hops_internal(
2374 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
2375 route_params.final_value_msat, logger, random_seed_bytes)?;
2376 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
2380 fn build_route_from_hops_internal<L: Deref>(
2381 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
2382 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, logger: L,
2383 random_seed_bytes: &[u8; 32]
2384 ) -> Result<Route, LightningError> where L::Target: Logger {
2387 our_node_id: NodeId,
2388 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
2391 impl Score for HopScorer {
2392 type ScoreParams = ();
2393 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
2394 _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
2396 let mut cur_id = self.our_node_id;
2397 for i in 0..self.hop_ids.len() {
2398 if let Some(next_id) = self.hop_ids[i] {
2399 if cur_id == *source && next_id == *target {
2410 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2412 fn payment_path_successful(&mut self, _path: &Path) {}
2414 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2416 fn probe_successful(&mut self, _path: &Path) {}
2419 impl<'a> Writeable for HopScorer {
2421 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
2426 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
2427 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
2430 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
2431 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
2432 for i in 0..hops.len() {
2433 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
2436 let scorer = HopScorer { our_node_id, hop_ids };
2438 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
2439 logger, &scorer, &(), random_seed_bytes)
2444 use crate::blinded_path::{BlindedHop, BlindedPath};
2445 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
2446 use crate::routing::utxo::UtxoResult;
2447 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
2448 BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
2449 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
2450 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
2451 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
2452 use crate::chain::transaction::OutPoint;
2453 use crate::sign::EntropySource;
2454 use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
2455 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
2456 use crate::ln::channelmanager;
2457 use crate::util::config::UserConfig;
2458 use crate::util::test_utils as ln_test_utils;
2459 use crate::util::chacha20::ChaCha20;
2460 use crate::util::ser::{Readable, Writeable};
2462 use crate::util::ser::Writer;
2464 use bitcoin::hashes::Hash;
2465 use bitcoin::network::constants::Network;
2466 use bitcoin::blockdata::constants::genesis_block;
2467 use bitcoin::blockdata::script::Builder;
2468 use bitcoin::blockdata::opcodes;
2469 use bitcoin::blockdata::transaction::TxOut;
2473 use bitcoin::secp256k1::{PublicKey,SecretKey};
2474 use bitcoin::secp256k1::Secp256k1;
2476 use crate::io::Cursor;
2477 use crate::prelude::*;
2478 use crate::sync::Arc;
2480 use core::convert::TryInto;
2482 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
2483 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
2484 channelmanager::ChannelDetails {
2485 channel_id: [0; 32],
2486 counterparty: channelmanager::ChannelCounterparty {
2489 unspendable_punishment_reserve: 0,
2490 forwarding_info: None,
2491 outbound_htlc_minimum_msat: None,
2492 outbound_htlc_maximum_msat: None,
2494 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2497 outbound_scid_alias: None,
2498 inbound_scid_alias: None,
2499 channel_value_satoshis: 0,
2502 outbound_capacity_msat,
2503 next_outbound_htlc_limit_msat: outbound_capacity_msat,
2504 next_outbound_htlc_minimum_msat: 0,
2505 inbound_capacity_msat: 42,
2506 unspendable_punishment_reserve: None,
2507 confirmations_required: None,
2508 confirmations: None,
2509 force_close_spend_delay: None,
2510 is_outbound: true, is_channel_ready: true,
2511 is_usable: true, is_public: true,
2512 inbound_htlc_minimum_msat: None,
2513 inbound_htlc_maximum_msat: None,
2515 feerate_sat_per_1000_weight: None
2520 fn simple_route_test() {
2521 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2522 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2523 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2524 let scorer = ln_test_utils::TestScorer::new();
2525 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2526 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2528 // Simple route to 2 via 1
2530 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 0, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2531 assert_eq!(err, "Cannot send a payment of 0 msat");
2532 } else { panic!(); }
2534 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2535 assert_eq!(route.paths[0].hops.len(), 2);
2537 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2538 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2539 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
2540 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2541 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2542 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2544 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2545 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2546 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2547 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2548 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2549 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2553 fn invalid_first_hop_test() {
2554 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2555 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2556 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2557 let scorer = ln_test_utils::TestScorer::new();
2558 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2559 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2561 // Simple route to 2 via 1
2563 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2565 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2566 get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2567 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2568 } else { panic!(); }
2570 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2571 assert_eq!(route.paths[0].hops.len(), 2);
2575 fn htlc_minimum_test() {
2576 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2577 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2578 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2579 let scorer = ln_test_utils::TestScorer::new();
2580 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2581 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2583 // Simple route to 2 via 1
2585 // Disable other paths
2586 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2587 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2588 short_channel_id: 12,
2590 flags: 2, // to disable
2591 cltv_expiry_delta: 0,
2592 htlc_minimum_msat: 0,
2593 htlc_maximum_msat: MAX_VALUE_MSAT,
2595 fee_proportional_millionths: 0,
2596 excess_data: Vec::new()
2598 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2599 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2600 short_channel_id: 3,
2602 flags: 2, // to disable
2603 cltv_expiry_delta: 0,
2604 htlc_minimum_msat: 0,
2605 htlc_maximum_msat: MAX_VALUE_MSAT,
2607 fee_proportional_millionths: 0,
2608 excess_data: Vec::new()
2610 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2611 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2612 short_channel_id: 13,
2614 flags: 2, // to disable
2615 cltv_expiry_delta: 0,
2616 htlc_minimum_msat: 0,
2617 htlc_maximum_msat: MAX_VALUE_MSAT,
2619 fee_proportional_millionths: 0,
2620 excess_data: Vec::new()
2622 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2623 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2624 short_channel_id: 6,
2626 flags: 2, // to disable
2627 cltv_expiry_delta: 0,
2628 htlc_minimum_msat: 0,
2629 htlc_maximum_msat: MAX_VALUE_MSAT,
2631 fee_proportional_millionths: 0,
2632 excess_data: Vec::new()
2634 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2635 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2636 short_channel_id: 7,
2638 flags: 2, // to disable
2639 cltv_expiry_delta: 0,
2640 htlc_minimum_msat: 0,
2641 htlc_maximum_msat: MAX_VALUE_MSAT,
2643 fee_proportional_millionths: 0,
2644 excess_data: Vec::new()
2647 // Check against amount_to_transfer_over_msat.
2648 // Set minimal HTLC of 200_000_000 msat.
2649 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2650 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2651 short_channel_id: 2,
2654 cltv_expiry_delta: 0,
2655 htlc_minimum_msat: 200_000_000,
2656 htlc_maximum_msat: MAX_VALUE_MSAT,
2658 fee_proportional_millionths: 0,
2659 excess_data: Vec::new()
2662 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2664 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2665 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2666 short_channel_id: 4,
2669 cltv_expiry_delta: 0,
2670 htlc_minimum_msat: 0,
2671 htlc_maximum_msat: 199_999_999,
2673 fee_proportional_millionths: 0,
2674 excess_data: Vec::new()
2677 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2678 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2679 assert_eq!(err, "Failed to find a path to the given destination");
2680 } else { panic!(); }
2682 // Lift the restriction on the first hop.
2683 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2684 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2685 short_channel_id: 2,
2688 cltv_expiry_delta: 0,
2689 htlc_minimum_msat: 0,
2690 htlc_maximum_msat: MAX_VALUE_MSAT,
2692 fee_proportional_millionths: 0,
2693 excess_data: Vec::new()
2696 // A payment above the minimum should pass
2697 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2698 assert_eq!(route.paths[0].hops.len(), 2);
2702 fn htlc_minimum_overpay_test() {
2703 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2704 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2705 let config = UserConfig::default();
2706 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
2707 let scorer = ln_test_utils::TestScorer::new();
2708 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2709 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2711 // A route to node#2 via two paths.
2712 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2713 // Thus, they can't send 60 without overpaying.
2714 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2715 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2716 short_channel_id: 2,
2719 cltv_expiry_delta: 0,
2720 htlc_minimum_msat: 35_000,
2721 htlc_maximum_msat: 40_000,
2723 fee_proportional_millionths: 0,
2724 excess_data: Vec::new()
2726 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2727 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2728 short_channel_id: 12,
2731 cltv_expiry_delta: 0,
2732 htlc_minimum_msat: 35_000,
2733 htlc_maximum_msat: 40_000,
2735 fee_proportional_millionths: 0,
2736 excess_data: Vec::new()
2740 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2741 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2742 short_channel_id: 13,
2745 cltv_expiry_delta: 0,
2746 htlc_minimum_msat: 0,
2747 htlc_maximum_msat: MAX_VALUE_MSAT,
2749 fee_proportional_millionths: 0,
2750 excess_data: Vec::new()
2752 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2753 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2754 short_channel_id: 4,
2757 cltv_expiry_delta: 0,
2758 htlc_minimum_msat: 0,
2759 htlc_maximum_msat: MAX_VALUE_MSAT,
2761 fee_proportional_millionths: 0,
2762 excess_data: Vec::new()
2765 // Disable other paths
2766 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2767 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2768 short_channel_id: 1,
2770 flags: 2, // to disable
2771 cltv_expiry_delta: 0,
2772 htlc_minimum_msat: 0,
2773 htlc_maximum_msat: MAX_VALUE_MSAT,
2775 fee_proportional_millionths: 0,
2776 excess_data: Vec::new()
2779 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2780 // Overpay fees to hit htlc_minimum_msat.
2781 let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
2782 // TODO: this could be better balanced to overpay 10k and not 15k.
2783 assert_eq!(overpaid_fees, 15_000);
2785 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2786 // while taking even more fee to match htlc_minimum_msat.
2787 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2788 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2789 short_channel_id: 12,
2792 cltv_expiry_delta: 0,
2793 htlc_minimum_msat: 65_000,
2794 htlc_maximum_msat: 80_000,
2796 fee_proportional_millionths: 0,
2797 excess_data: Vec::new()
2799 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2800 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2801 short_channel_id: 2,
2804 cltv_expiry_delta: 0,
2805 htlc_minimum_msat: 0,
2806 htlc_maximum_msat: MAX_VALUE_MSAT,
2808 fee_proportional_millionths: 0,
2809 excess_data: Vec::new()
2811 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2812 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2813 short_channel_id: 4,
2816 cltv_expiry_delta: 0,
2817 htlc_minimum_msat: 0,
2818 htlc_maximum_msat: MAX_VALUE_MSAT,
2820 fee_proportional_millionths: 100_000,
2821 excess_data: Vec::new()
2824 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2825 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2826 assert_eq!(route.paths.len(), 1);
2827 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
2828 let fees = route.paths[0].hops[0].fee_msat;
2829 assert_eq!(fees, 5_000);
2831 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2832 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2833 // the other channel.
2834 assert_eq!(route.paths.len(), 1);
2835 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2836 let fees = route.paths[0].hops[0].fee_msat;
2837 assert_eq!(fees, 5_000);
2841 fn disable_channels_test() {
2842 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2843 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2844 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2845 let scorer = ln_test_utils::TestScorer::new();
2846 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2847 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2849 // // Disable channels 4 and 12 by flags=2
2850 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2852 short_channel_id: 4,
2854 flags: 2, // to disable
2855 cltv_expiry_delta: 0,
2856 htlc_minimum_msat: 0,
2857 htlc_maximum_msat: MAX_VALUE_MSAT,
2859 fee_proportional_millionths: 0,
2860 excess_data: Vec::new()
2862 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2863 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2864 short_channel_id: 12,
2866 flags: 2, // to disable
2867 cltv_expiry_delta: 0,
2868 htlc_minimum_msat: 0,
2869 htlc_maximum_msat: MAX_VALUE_MSAT,
2871 fee_proportional_millionths: 0,
2872 excess_data: Vec::new()
2875 // If all the channels require some features we don't understand, route should fail
2876 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2877 assert_eq!(err, "Failed to find a path to the given destination");
2878 } else { panic!(); }
2880 // If we specify a channel to node7, that overrides our local channel view and that gets used
2881 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2882 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2883 assert_eq!(route.paths[0].hops.len(), 2);
2885 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2886 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2887 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2888 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2889 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2890 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2892 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2893 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2894 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2895 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2896 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2897 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2901 fn disable_node_test() {
2902 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2903 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2904 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2905 let scorer = ln_test_utils::TestScorer::new();
2906 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2907 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2909 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2910 let mut unknown_features = NodeFeatures::empty();
2911 unknown_features.set_unknown_feature_required();
2912 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2913 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2914 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2916 // If all nodes require some features we don't understand, route should fail
2917 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2918 assert_eq!(err, "Failed to find a path to the given destination");
2919 } else { panic!(); }
2921 // If we specify a channel to node7, that overrides our local channel view and that gets used
2922 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2923 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2924 assert_eq!(route.paths[0].hops.len(), 2);
2926 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2927 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2928 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2929 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2930 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2931 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2933 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2934 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2935 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2936 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2937 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2938 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2940 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2941 // naively) assume that the user checked the feature bits on the invoice, which override
2942 // the node_announcement.
2946 fn our_chans_test() {
2947 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2948 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2949 let scorer = ln_test_utils::TestScorer::new();
2950 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2951 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2953 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2954 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
2955 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2956 assert_eq!(route.paths[0].hops.len(), 3);
2958 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2959 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2960 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2961 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2962 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2963 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2965 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2966 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2967 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2968 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (3 << 4) | 2);
2969 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2970 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2972 assert_eq!(route.paths[0].hops[2].pubkey, nodes[0]);
2973 assert_eq!(route.paths[0].hops[2].short_channel_id, 3);
2974 assert_eq!(route.paths[0].hops[2].fee_msat, 100);
2975 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
2976 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(1));
2977 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(3));
2979 // If we specify a channel to node7, that overrides our local channel view and that gets used
2980 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2981 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2982 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2983 assert_eq!(route.paths[0].hops.len(), 2);
2985 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2986 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2987 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2988 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2989 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
2990 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2992 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2993 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2994 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2995 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2996 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2997 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3000 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3001 let zero_fees = RoutingFees {
3003 proportional_millionths: 0,
3005 vec![RouteHint(vec![RouteHintHop {
3006 src_node_id: nodes[3],
3007 short_channel_id: 8,
3009 cltv_expiry_delta: (8 << 4) | 1,
3010 htlc_minimum_msat: None,
3011 htlc_maximum_msat: None,
3013 ]), RouteHint(vec![RouteHintHop {
3014 src_node_id: nodes[4],
3015 short_channel_id: 9,
3018 proportional_millionths: 0,
3020 cltv_expiry_delta: (9 << 4) | 1,
3021 htlc_minimum_msat: None,
3022 htlc_maximum_msat: None,
3023 }]), RouteHint(vec![RouteHintHop {
3024 src_node_id: nodes[5],
3025 short_channel_id: 10,
3027 cltv_expiry_delta: (10 << 4) | 1,
3028 htlc_minimum_msat: None,
3029 htlc_maximum_msat: None,
3033 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3034 let zero_fees = RoutingFees {
3036 proportional_millionths: 0,
3038 vec![RouteHint(vec![RouteHintHop {
3039 src_node_id: nodes[2],
3040 short_channel_id: 5,
3043 proportional_millionths: 0,
3045 cltv_expiry_delta: (5 << 4) | 1,
3046 htlc_minimum_msat: None,
3047 htlc_maximum_msat: None,
3049 src_node_id: nodes[3],
3050 short_channel_id: 8,
3052 cltv_expiry_delta: (8 << 4) | 1,
3053 htlc_minimum_msat: None,
3054 htlc_maximum_msat: None,
3056 ]), RouteHint(vec![RouteHintHop {
3057 src_node_id: nodes[4],
3058 short_channel_id: 9,
3061 proportional_millionths: 0,
3063 cltv_expiry_delta: (9 << 4) | 1,
3064 htlc_minimum_msat: None,
3065 htlc_maximum_msat: None,
3066 }]), RouteHint(vec![RouteHintHop {
3067 src_node_id: nodes[5],
3068 short_channel_id: 10,
3070 cltv_expiry_delta: (10 << 4) | 1,
3071 htlc_minimum_msat: None,
3072 htlc_maximum_msat: None,
3077 fn partial_route_hint_test() {
3078 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3079 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3080 let scorer = ln_test_utils::TestScorer::new();
3081 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3082 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3084 // Simple test across 2, 3, 5, and 4 via a last_hop channel
3085 // Tests the behaviour when the RouteHint contains a suboptimal hop.
3086 // RouteHint may be partially used by the algo to build the best path.
3088 // First check that last hop can't have its source as the payee.
3089 let invalid_last_hop = RouteHint(vec![RouteHintHop {
3090 src_node_id: nodes[6],
3091 short_channel_id: 8,
3094 proportional_millionths: 0,
3096 cltv_expiry_delta: (8 << 4) | 1,
3097 htlc_minimum_msat: None,
3098 htlc_maximum_msat: None,
3101 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
3102 invalid_last_hops.push(invalid_last_hop);
3104 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops).unwrap();
3105 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3106 assert_eq!(err, "Route hint cannot have the payee as the source.");
3107 } else { panic!(); }
3110 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
3111 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3112 assert_eq!(route.paths[0].hops.len(), 5);
3114 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3115 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3116 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3117 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3118 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3119 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3121 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3122 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3123 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3124 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3125 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3126 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3128 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3129 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3130 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3131 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3132 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3133 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3135 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3136 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3137 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3138 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3139 // If we have a peer in the node map, we'll use their features here since we don't have
3140 // a way of figuring out their features from the invoice:
3141 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3142 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3144 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3145 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3146 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3147 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3148 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3149 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3152 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3153 let zero_fees = RoutingFees {
3155 proportional_millionths: 0,
3157 vec![RouteHint(vec![RouteHintHop {
3158 src_node_id: nodes[3],
3159 short_channel_id: 8,
3161 cltv_expiry_delta: (8 << 4) | 1,
3162 htlc_minimum_msat: None,
3163 htlc_maximum_msat: None,
3164 }]), RouteHint(vec![
3166 ]), RouteHint(vec![RouteHintHop {
3167 src_node_id: nodes[5],
3168 short_channel_id: 10,
3170 cltv_expiry_delta: (10 << 4) | 1,
3171 htlc_minimum_msat: None,
3172 htlc_maximum_msat: None,
3177 fn ignores_empty_last_hops_test() {
3178 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3179 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3180 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes)).unwrap();
3181 let scorer = ln_test_utils::TestScorer::new();
3182 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3183 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3185 // Test handling of an empty RouteHint passed in Invoice.
3187 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3188 assert_eq!(route.paths[0].hops.len(), 5);
3190 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3191 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3192 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3193 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3194 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3195 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3197 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3198 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3199 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3200 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3201 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3202 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3204 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3205 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3206 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3207 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3208 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3209 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3211 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3212 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3213 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3214 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3215 // If we have a peer in the node map, we'll use their features here since we don't have
3216 // a way of figuring out their features from the invoice:
3217 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3218 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3220 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3221 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3222 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3223 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3224 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3225 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3228 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3230 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3231 let zero_fees = RoutingFees {
3233 proportional_millionths: 0,
3235 vec![RouteHint(vec![RouteHintHop {
3236 src_node_id: hint_hops[0],
3237 short_channel_id: 0xff00,
3240 proportional_millionths: 0,
3242 cltv_expiry_delta: (5 << 4) | 1,
3243 htlc_minimum_msat: None,
3244 htlc_maximum_msat: None,
3246 src_node_id: hint_hops[1],
3247 short_channel_id: 0xff01,
3249 cltv_expiry_delta: (8 << 4) | 1,
3250 htlc_minimum_msat: None,
3251 htlc_maximum_msat: None,
3256 fn multi_hint_last_hops_test() {
3257 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3258 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3259 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3260 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3261 let scorer = ln_test_utils::TestScorer::new();
3262 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3263 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3264 // Test through channels 2, 3, 0xff00, 0xff01.
3265 // Test shows that multiple hop hints are considered.
3267 // Disabling channels 6 & 7 by flags=2
3268 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3269 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3270 short_channel_id: 6,
3272 flags: 2, // to disable
3273 cltv_expiry_delta: 0,
3274 htlc_minimum_msat: 0,
3275 htlc_maximum_msat: MAX_VALUE_MSAT,
3277 fee_proportional_millionths: 0,
3278 excess_data: Vec::new()
3280 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3281 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3282 short_channel_id: 7,
3284 flags: 2, // to disable
3285 cltv_expiry_delta: 0,
3286 htlc_minimum_msat: 0,
3287 htlc_maximum_msat: MAX_VALUE_MSAT,
3289 fee_proportional_millionths: 0,
3290 excess_data: Vec::new()
3293 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3294 assert_eq!(route.paths[0].hops.len(), 4);
3296 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3297 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3298 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3299 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3300 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3301 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3303 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3304 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3305 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3306 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3307 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3308 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3310 assert_eq!(route.paths[0].hops[2].pubkey, nodes[3]);
3311 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3312 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3313 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3314 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(4));
3315 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3317 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3318 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3319 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3320 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3321 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3322 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3326 fn private_multi_hint_last_hops_test() {
3327 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3328 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3330 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3331 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3333 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3334 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3335 let scorer = ln_test_utils::TestScorer::new();
3336 // Test through channels 2, 3, 0xff00, 0xff01.
3337 // Test shows that multiple hop hints are considered.
3339 // Disabling channels 6 & 7 by flags=2
3340 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3341 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3342 short_channel_id: 6,
3344 flags: 2, // to disable
3345 cltv_expiry_delta: 0,
3346 htlc_minimum_msat: 0,
3347 htlc_maximum_msat: MAX_VALUE_MSAT,
3349 fee_proportional_millionths: 0,
3350 excess_data: Vec::new()
3352 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3353 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3354 short_channel_id: 7,
3356 flags: 2, // to disable
3357 cltv_expiry_delta: 0,
3358 htlc_minimum_msat: 0,
3359 htlc_maximum_msat: MAX_VALUE_MSAT,
3361 fee_proportional_millionths: 0,
3362 excess_data: Vec::new()
3365 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &[42u8; 32]).unwrap();
3366 assert_eq!(route.paths[0].hops.len(), 4);
3368 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3369 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3370 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3371 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3372 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3373 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3375 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3376 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3377 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3378 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3379 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3380 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3382 assert_eq!(route.paths[0].hops[2].pubkey, non_announced_pubkey);
3383 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3384 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3385 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3386 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3387 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3389 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3390 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3391 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3392 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3393 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3394 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3397 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3398 let zero_fees = RoutingFees {
3400 proportional_millionths: 0,
3402 vec![RouteHint(vec![RouteHintHop {
3403 src_node_id: nodes[4],
3404 short_channel_id: 11,
3406 cltv_expiry_delta: (11 << 4) | 1,
3407 htlc_minimum_msat: None,
3408 htlc_maximum_msat: None,
3410 src_node_id: nodes[3],
3411 short_channel_id: 8,
3413 cltv_expiry_delta: (8 << 4) | 1,
3414 htlc_minimum_msat: None,
3415 htlc_maximum_msat: None,
3416 }]), RouteHint(vec![RouteHintHop {
3417 src_node_id: nodes[4],
3418 short_channel_id: 9,
3421 proportional_millionths: 0,
3423 cltv_expiry_delta: (9 << 4) | 1,
3424 htlc_minimum_msat: None,
3425 htlc_maximum_msat: None,
3426 }]), RouteHint(vec![RouteHintHop {
3427 src_node_id: nodes[5],
3428 short_channel_id: 10,
3430 cltv_expiry_delta: (10 << 4) | 1,
3431 htlc_minimum_msat: None,
3432 htlc_maximum_msat: None,
3437 fn last_hops_with_public_channel_test() {
3438 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3439 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3440 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes)).unwrap();
3441 let scorer = ln_test_utils::TestScorer::new();
3442 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3443 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3444 // This test shows that public routes can be present in the invoice
3445 // which would be handled in the same manner.
3447 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3448 assert_eq!(route.paths[0].hops.len(), 5);
3450 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3451 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3452 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3453 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3454 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3455 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3457 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3458 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3459 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3460 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3461 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3462 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3464 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3465 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3466 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3467 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3468 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3469 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3471 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3472 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3473 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3474 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3475 // If we have a peer in the node map, we'll use their features here since we don't have
3476 // a way of figuring out their features from the invoice:
3477 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3478 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3480 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3481 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3482 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3483 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3484 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3485 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3489 fn our_chans_last_hop_connect_test() {
3490 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3491 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3492 let scorer = ln_test_utils::TestScorer::new();
3493 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3494 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3496 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3497 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3498 let mut last_hops = last_hops(&nodes);
3499 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3500 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3501 assert_eq!(route.paths[0].hops.len(), 2);
3503 assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
3504 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3505 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
3506 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3507 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3508 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3510 assert_eq!(route.paths[0].hops[1].pubkey, nodes[6]);
3511 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3512 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3513 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3514 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3515 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3517 last_hops[0].0[0].fees.base_msat = 1000;
3519 // Revert to via 6 as the fee on 8 goes up
3520 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops).unwrap();
3521 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3522 assert_eq!(route.paths[0].hops.len(), 4);
3524 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3525 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3526 assert_eq!(route.paths[0].hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
3527 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3528 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3529 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3531 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3532 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3533 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3534 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (7 << 4) | 1);
3535 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3536 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3538 assert_eq!(route.paths[0].hops[2].pubkey, nodes[5]);
3539 assert_eq!(route.paths[0].hops[2].short_channel_id, 7);
3540 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3541 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (10 << 4) | 1);
3542 // If we have a peer in the node map, we'll use their features here since we don't have
3543 // a way of figuring out their features from the invoice:
3544 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
3545 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(7));
3547 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3548 assert_eq!(route.paths[0].hops[3].short_channel_id, 10);
3549 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3550 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3551 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3552 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3554 // ...but still use 8 for larger payments as 6 has a variable feerate
3555 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3556 assert_eq!(route.paths[0].hops.len(), 5);
3558 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3559 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3560 assert_eq!(route.paths[0].hops[0].fee_msat, 3000);
3561 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3562 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3563 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3565 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3566 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3567 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3568 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3569 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3570 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3572 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3573 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3574 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3575 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3576 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3577 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3579 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3580 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3581 assert_eq!(route.paths[0].hops[3].fee_msat, 1000);
3582 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3583 // If we have a peer in the node map, we'll use their features here since we don't have
3584 // a way of figuring out their features from the invoice:
3585 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3586 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3588 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3589 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3590 assert_eq!(route.paths[0].hops[4].fee_msat, 2000);
3591 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3592 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3593 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3596 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> {
3597 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3598 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3599 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3601 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3602 let last_hops = RouteHint(vec![RouteHintHop {
3603 src_node_id: middle_node_id,
3604 short_channel_id: 8,
3607 proportional_millionths: last_hop_fee_prop,
3609 cltv_expiry_delta: (8 << 4) | 1,
3610 htlc_minimum_msat: None,
3611 htlc_maximum_msat: last_hop_htlc_max,
3613 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]).unwrap();
3614 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3615 let scorer = ln_test_utils::TestScorer::new();
3616 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3617 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3618 let logger = ln_test_utils::TestLogger::new();
3619 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
3620 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3621 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, &logger, &scorer, &(), &random_seed_bytes);
3626 fn unannounced_path_test() {
3627 // We should be able to send a payment to a destination without any help of a routing graph
3628 // if we have a channel with a common counterparty that appears in the first and last hop
3630 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3632 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3633 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3634 assert_eq!(route.paths[0].hops.len(), 2);
3636 assert_eq!(route.paths[0].hops[0].pubkey, middle_node_id);
3637 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3638 assert_eq!(route.paths[0].hops[0].fee_msat, 1001);
3639 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3640 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &[0b11]);
3641 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3643 assert_eq!(route.paths[0].hops[1].pubkey, target_node_id);
3644 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3645 assert_eq!(route.paths[0].hops[1].fee_msat, 1000000);
3646 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3647 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3648 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3652 fn overflow_unannounced_path_test_liquidity_underflow() {
3653 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3654 // the last-hop had a fee which overflowed a u64, we'd panic.
3655 // This was due to us adding the first-hop from us unconditionally, causing us to think
3656 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3657 // In this test, we previously hit a subtraction underflow due to having less available
3658 // liquidity at the last hop than 0.
3659 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());
3663 fn overflow_unannounced_path_test_feerate_overflow() {
3664 // This tests for the same case as above, except instead of hitting a subtraction
3665 // underflow, we hit a case where the fee charged at a hop overflowed.
3666 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());
3670 fn available_amount_while_routing_test() {
3671 // Tests whether we choose the correct available channel amount while routing.
3673 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3674 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3675 let scorer = ln_test_utils::TestScorer::new();
3676 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3677 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3678 let config = UserConfig::default();
3679 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
3681 // We will use a simple single-path route from
3682 // our node to node2 via node0: channels {1, 3}.
3684 // First disable all other paths.
3685 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3686 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3687 short_channel_id: 2,
3690 cltv_expiry_delta: 0,
3691 htlc_minimum_msat: 0,
3692 htlc_maximum_msat: 100_000,
3694 fee_proportional_millionths: 0,
3695 excess_data: Vec::new()
3697 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3698 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3699 short_channel_id: 12,
3702 cltv_expiry_delta: 0,
3703 htlc_minimum_msat: 0,
3704 htlc_maximum_msat: 100_000,
3706 fee_proportional_millionths: 0,
3707 excess_data: Vec::new()
3710 // Make the first channel (#1) very permissive,
3711 // and we will be testing all limits on the second channel.
3712 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3713 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3714 short_channel_id: 1,
3717 cltv_expiry_delta: 0,
3718 htlc_minimum_msat: 0,
3719 htlc_maximum_msat: 1_000_000_000,
3721 fee_proportional_millionths: 0,
3722 excess_data: Vec::new()
3725 // First, let's see if routing works if we have absolutely no idea about the available amount.
3726 // In this case, it should be set to 250_000 sats.
3727 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3728 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3729 short_channel_id: 3,
3732 cltv_expiry_delta: 0,
3733 htlc_minimum_msat: 0,
3734 htlc_maximum_msat: 250_000_000,
3736 fee_proportional_millionths: 0,
3737 excess_data: Vec::new()
3741 // Attempt to route more than available results in a failure.
3742 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3743 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3744 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3745 } else { panic!(); }
3749 // Now, attempt to route an exact amount we have should be fine.
3750 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, Arc::clone(&logger), &scorer, &(),&random_seed_bytes).unwrap();
3751 assert_eq!(route.paths.len(), 1);
3752 let path = route.paths.last().unwrap();
3753 assert_eq!(path.hops.len(), 2);
3754 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3755 assert_eq!(path.final_value_msat(), 250_000_000);
3758 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3759 // Disable channel #1 and use another first hop.
3760 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3761 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3762 short_channel_id: 1,
3765 cltv_expiry_delta: 0,
3766 htlc_minimum_msat: 0,
3767 htlc_maximum_msat: 1_000_000_000,
3769 fee_proportional_millionths: 0,
3770 excess_data: Vec::new()
3773 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3774 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3777 // Attempt to route more than available results in a failure.
3778 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3779 &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3780 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3781 } else { panic!(); }
3785 // Now, attempt to route an exact amount we have should be fine.
3786 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3787 assert_eq!(route.paths.len(), 1);
3788 let path = route.paths.last().unwrap();
3789 assert_eq!(path.hops.len(), 2);
3790 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3791 assert_eq!(path.final_value_msat(), 200_000_000);
3794 // Enable channel #1 back.
3795 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3796 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3797 short_channel_id: 1,
3800 cltv_expiry_delta: 0,
3801 htlc_minimum_msat: 0,
3802 htlc_maximum_msat: 1_000_000_000,
3804 fee_proportional_millionths: 0,
3805 excess_data: Vec::new()
3809 // Now let's see if routing works if we know only htlc_maximum_msat.
3810 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3811 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3812 short_channel_id: 3,
3815 cltv_expiry_delta: 0,
3816 htlc_minimum_msat: 0,
3817 htlc_maximum_msat: 15_000,
3819 fee_proportional_millionths: 0,
3820 excess_data: Vec::new()
3824 // Attempt to route more than available results in a failure.
3825 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3826 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3827 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3828 } else { panic!(); }
3832 // Now, attempt to route an exact amount we have should be fine.
3833 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3834 assert_eq!(route.paths.len(), 1);
3835 let path = route.paths.last().unwrap();
3836 assert_eq!(path.hops.len(), 2);
3837 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3838 assert_eq!(path.final_value_msat(), 15_000);
3841 // Now let's see if routing works if we know only capacity from the UTXO.
3843 // We can't change UTXO capacity on the fly, so we'll disable
3844 // the existing channel and add another one with the capacity we need.
3845 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3846 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3847 short_channel_id: 3,
3850 cltv_expiry_delta: 0,
3851 htlc_minimum_msat: 0,
3852 htlc_maximum_msat: MAX_VALUE_MSAT,
3854 fee_proportional_millionths: 0,
3855 excess_data: Vec::new()
3858 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3859 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3860 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3861 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3862 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3864 *chain_monitor.utxo_ret.lock().unwrap() =
3865 UtxoResult::Sync(Ok(TxOut { value: 15, script_pubkey: good_script.clone() }));
3866 gossip_sync.add_utxo_lookup(Some(chain_monitor));
3868 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3869 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3870 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3871 short_channel_id: 333,
3874 cltv_expiry_delta: (3 << 4) | 1,
3875 htlc_minimum_msat: 0,
3876 htlc_maximum_msat: 15_000,
3878 fee_proportional_millionths: 0,
3879 excess_data: Vec::new()
3881 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3882 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3883 short_channel_id: 333,
3886 cltv_expiry_delta: (3 << 4) | 2,
3887 htlc_minimum_msat: 0,
3888 htlc_maximum_msat: 15_000,
3890 fee_proportional_millionths: 0,
3891 excess_data: Vec::new()
3895 // Attempt to route more than available results in a failure.
3896 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3897 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3898 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3899 } else { panic!(); }
3903 // Now, attempt to route an exact amount we have should be fine.
3904 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3905 assert_eq!(route.paths.len(), 1);
3906 let path = route.paths.last().unwrap();
3907 assert_eq!(path.hops.len(), 2);
3908 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3909 assert_eq!(path.final_value_msat(), 15_000);
3912 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3913 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3914 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3915 short_channel_id: 333,
3918 cltv_expiry_delta: 0,
3919 htlc_minimum_msat: 0,
3920 htlc_maximum_msat: 10_000,
3922 fee_proportional_millionths: 0,
3923 excess_data: Vec::new()
3927 // Attempt to route more than available results in a failure.
3928 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3929 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3930 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3931 } else { panic!(); }
3935 // Now, attempt to route an exact amount we have should be fine.
3936 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3937 assert_eq!(route.paths.len(), 1);
3938 let path = route.paths.last().unwrap();
3939 assert_eq!(path.hops.len(), 2);
3940 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3941 assert_eq!(path.final_value_msat(), 10_000);
3946 fn available_liquidity_last_hop_test() {
3947 // Check that available liquidity properly limits the path even when only
3948 // one of the latter hops is limited.
3949 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3950 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3951 let scorer = ln_test_utils::TestScorer::new();
3952 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3953 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3954 let config = UserConfig::default();
3955 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
3957 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3958 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3959 // Total capacity: 50 sats.
3961 // Disable other potential paths.
3962 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3963 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3964 short_channel_id: 2,
3967 cltv_expiry_delta: 0,
3968 htlc_minimum_msat: 0,
3969 htlc_maximum_msat: 100_000,
3971 fee_proportional_millionths: 0,
3972 excess_data: Vec::new()
3974 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3975 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3976 short_channel_id: 7,
3979 cltv_expiry_delta: 0,
3980 htlc_minimum_msat: 0,
3981 htlc_maximum_msat: 100_000,
3983 fee_proportional_millionths: 0,
3984 excess_data: Vec::new()
3989 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3990 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3991 short_channel_id: 12,
3994 cltv_expiry_delta: 0,
3995 htlc_minimum_msat: 0,
3996 htlc_maximum_msat: 100_000,
3998 fee_proportional_millionths: 0,
3999 excess_data: Vec::new()
4001 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4002 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4003 short_channel_id: 13,
4006 cltv_expiry_delta: 0,
4007 htlc_minimum_msat: 0,
4008 htlc_maximum_msat: 100_000,
4010 fee_proportional_millionths: 0,
4011 excess_data: Vec::new()
4014 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4015 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4016 short_channel_id: 6,
4019 cltv_expiry_delta: 0,
4020 htlc_minimum_msat: 0,
4021 htlc_maximum_msat: 50_000,
4023 fee_proportional_millionths: 0,
4024 excess_data: Vec::new()
4026 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4027 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4028 short_channel_id: 11,
4031 cltv_expiry_delta: 0,
4032 htlc_minimum_msat: 0,
4033 htlc_maximum_msat: 100_000,
4035 fee_proportional_millionths: 0,
4036 excess_data: Vec::new()
4039 // Attempt to route more than available results in a failure.
4040 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4041 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4042 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4043 } else { panic!(); }
4047 // Now, attempt to route 49 sats (just a bit below the capacity).
4048 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4049 assert_eq!(route.paths.len(), 1);
4050 let mut total_amount_paid_msat = 0;
4051 for path in &route.paths {
4052 assert_eq!(path.hops.len(), 4);
4053 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4054 total_amount_paid_msat += path.final_value_msat();
4056 assert_eq!(total_amount_paid_msat, 49_000);
4060 // Attempt to route an exact amount is also fine
4061 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4062 assert_eq!(route.paths.len(), 1);
4063 let mut total_amount_paid_msat = 0;
4064 for path in &route.paths {
4065 assert_eq!(path.hops.len(), 4);
4066 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4067 total_amount_paid_msat += path.final_value_msat();
4069 assert_eq!(total_amount_paid_msat, 50_000);
4074 fn ignore_fee_first_hop_test() {
4075 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4076 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4077 let scorer = ln_test_utils::TestScorer::new();
4078 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4079 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4080 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
4082 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4083 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4084 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4085 short_channel_id: 1,
4088 cltv_expiry_delta: 0,
4089 htlc_minimum_msat: 0,
4090 htlc_maximum_msat: 100_000,
4091 fee_base_msat: 1_000_000,
4092 fee_proportional_millionths: 0,
4093 excess_data: Vec::new()
4095 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4096 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4097 short_channel_id: 3,
4100 cltv_expiry_delta: 0,
4101 htlc_minimum_msat: 0,
4102 htlc_maximum_msat: 50_000,
4104 fee_proportional_millionths: 0,
4105 excess_data: Vec::new()
4109 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4110 assert_eq!(route.paths.len(), 1);
4111 let mut total_amount_paid_msat = 0;
4112 for path in &route.paths {
4113 assert_eq!(path.hops.len(), 2);
4114 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4115 total_amount_paid_msat += path.final_value_msat();
4117 assert_eq!(total_amount_paid_msat, 50_000);
4122 fn simple_mpp_route_test() {
4123 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4124 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4125 let scorer = ln_test_utils::TestScorer::new();
4126 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4127 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4128 let config = UserConfig::default();
4129 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
4130 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4132 // We need a route consisting of 3 paths:
4133 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4134 // To achieve this, the amount being transferred should be around
4135 // the total capacity of these 3 paths.
4137 // First, we set limits on these (previously unlimited) channels.
4138 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4140 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4141 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4142 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4143 short_channel_id: 1,
4146 cltv_expiry_delta: 0,
4147 htlc_minimum_msat: 0,
4148 htlc_maximum_msat: 100_000,
4150 fee_proportional_millionths: 0,
4151 excess_data: Vec::new()
4153 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4154 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4155 short_channel_id: 3,
4158 cltv_expiry_delta: 0,
4159 htlc_minimum_msat: 0,
4160 htlc_maximum_msat: 50_000,
4162 fee_proportional_millionths: 0,
4163 excess_data: Vec::new()
4166 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4167 // (total limit 60).
4168 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4169 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4170 short_channel_id: 12,
4173 cltv_expiry_delta: 0,
4174 htlc_minimum_msat: 0,
4175 htlc_maximum_msat: 60_000,
4177 fee_proportional_millionths: 0,
4178 excess_data: Vec::new()
4180 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4181 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4182 short_channel_id: 13,
4185 cltv_expiry_delta: 0,
4186 htlc_minimum_msat: 0,
4187 htlc_maximum_msat: 60_000,
4189 fee_proportional_millionths: 0,
4190 excess_data: Vec::new()
4193 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4194 // (total capacity 180 sats).
4195 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4196 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4197 short_channel_id: 2,
4200 cltv_expiry_delta: 0,
4201 htlc_minimum_msat: 0,
4202 htlc_maximum_msat: 200_000,
4204 fee_proportional_millionths: 0,
4205 excess_data: Vec::new()
4207 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4208 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4209 short_channel_id: 4,
4212 cltv_expiry_delta: 0,
4213 htlc_minimum_msat: 0,
4214 htlc_maximum_msat: 180_000,
4216 fee_proportional_millionths: 0,
4217 excess_data: Vec::new()
4221 // Attempt to route more than available results in a failure.
4222 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4223 &our_id, &payment_params, &network_graph.read_only(), None, 300_000,
4224 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4225 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4226 } else { panic!(); }
4230 // Attempt to route while setting max_path_count to 0 results in a failure.
4231 let zero_payment_params = payment_params.clone().with_max_path_count(0);
4232 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4233 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100,
4234 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4235 assert_eq!(err, "Can't find a route with no paths allowed.");
4236 } else { panic!(); }
4240 // Attempt to route while setting max_path_count to 3 results in a failure.
4241 // This is the case because the minimal_value_contribution_msat would require each path
4242 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4243 let fail_payment_params = payment_params.clone().with_max_path_count(3);
4244 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4245 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000,
4246 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4247 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4248 } else { panic!(); }
4252 // Now, attempt to route 250 sats (just a bit below the capacity).
4253 // Our algorithm should provide us with these 3 paths.
4254 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4255 250_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4256 assert_eq!(route.paths.len(), 3);
4257 let mut total_amount_paid_msat = 0;
4258 for path in &route.paths {
4259 assert_eq!(path.hops.len(), 2);
4260 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4261 total_amount_paid_msat += path.final_value_msat();
4263 assert_eq!(total_amount_paid_msat, 250_000);
4267 // Attempt to route an exact amount is also fine
4268 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4269 290_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4270 assert_eq!(route.paths.len(), 3);
4271 let mut total_amount_paid_msat = 0;
4272 for path in &route.paths {
4273 assert_eq!(path.hops.len(), 2);
4274 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4275 total_amount_paid_msat += path.final_value_msat();
4277 assert_eq!(total_amount_paid_msat, 290_000);
4282 fn long_mpp_route_test() {
4283 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4284 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4285 let scorer = ln_test_utils::TestScorer::new();
4286 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4287 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4288 let config = UserConfig::default();
4289 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4291 // We need a route consisting of 3 paths:
4292 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4293 // Note that these paths overlap (channels 5, 12, 13).
4294 // We will route 300 sats.
4295 // Each path will have 100 sats capacity, those channels which
4296 // are used twice will have 200 sats capacity.
4298 // Disable other potential paths.
4299 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4300 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4301 short_channel_id: 2,
4304 cltv_expiry_delta: 0,
4305 htlc_minimum_msat: 0,
4306 htlc_maximum_msat: 100_000,
4308 fee_proportional_millionths: 0,
4309 excess_data: Vec::new()
4311 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4312 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4313 short_channel_id: 7,
4316 cltv_expiry_delta: 0,
4317 htlc_minimum_msat: 0,
4318 htlc_maximum_msat: 100_000,
4320 fee_proportional_millionths: 0,
4321 excess_data: Vec::new()
4324 // Path via {node0, node2} is channels {1, 3, 5}.
4325 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4326 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4327 short_channel_id: 1,
4330 cltv_expiry_delta: 0,
4331 htlc_minimum_msat: 0,
4332 htlc_maximum_msat: 100_000,
4334 fee_proportional_millionths: 0,
4335 excess_data: Vec::new()
4337 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4338 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4339 short_channel_id: 3,
4342 cltv_expiry_delta: 0,
4343 htlc_minimum_msat: 0,
4344 htlc_maximum_msat: 100_000,
4346 fee_proportional_millionths: 0,
4347 excess_data: Vec::new()
4350 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4351 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4352 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4353 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4354 short_channel_id: 5,
4357 cltv_expiry_delta: 0,
4358 htlc_minimum_msat: 0,
4359 htlc_maximum_msat: 200_000,
4361 fee_proportional_millionths: 0,
4362 excess_data: Vec::new()
4365 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4366 // Add 100 sats to the capacities of {12, 13}, because these channels
4367 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4368 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4369 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4370 short_channel_id: 12,
4373 cltv_expiry_delta: 0,
4374 htlc_minimum_msat: 0,
4375 htlc_maximum_msat: 200_000,
4377 fee_proportional_millionths: 0,
4378 excess_data: Vec::new()
4380 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4381 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4382 short_channel_id: 13,
4385 cltv_expiry_delta: 0,
4386 htlc_minimum_msat: 0,
4387 htlc_maximum_msat: 200_000,
4389 fee_proportional_millionths: 0,
4390 excess_data: Vec::new()
4393 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4394 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4395 short_channel_id: 6,
4398 cltv_expiry_delta: 0,
4399 htlc_minimum_msat: 0,
4400 htlc_maximum_msat: 100_000,
4402 fee_proportional_millionths: 0,
4403 excess_data: Vec::new()
4405 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4406 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4407 short_channel_id: 11,
4410 cltv_expiry_delta: 0,
4411 htlc_minimum_msat: 0,
4412 htlc_maximum_msat: 100_000,
4414 fee_proportional_millionths: 0,
4415 excess_data: Vec::new()
4418 // Path via {node7, node2} is channels {12, 13, 5}.
4419 // We already limited them to 200 sats (they are used twice for 100 sats).
4420 // Nothing to do here.
4423 // Attempt to route more than available results in a failure.
4424 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4425 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4426 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4427 } else { panic!(); }
4431 // Now, attempt to route 300 sats (exact amount we can route).
4432 // Our algorithm should provide us with these 3 paths, 100 sats each.
4433 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4434 assert_eq!(route.paths.len(), 3);
4436 let mut total_amount_paid_msat = 0;
4437 for path in &route.paths {
4438 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4439 total_amount_paid_msat += path.final_value_msat();
4441 assert_eq!(total_amount_paid_msat, 300_000);
4447 fn mpp_cheaper_route_test() {
4448 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4449 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4450 let scorer = ln_test_utils::TestScorer::new();
4451 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4452 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4453 let config = UserConfig::default();
4454 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4456 // This test checks that if we have two cheaper paths and one more expensive path,
4457 // so that liquidity-wise any 2 of 3 combination is sufficient,
4458 // two cheaper paths will be taken.
4459 // These paths have equal available liquidity.
4461 // We need a combination of 3 paths:
4462 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4463 // Note that these paths overlap (channels 5, 12, 13).
4464 // Each path will have 100 sats capacity, those channels which
4465 // are used twice will have 200 sats capacity.
4467 // Disable other potential paths.
4468 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4469 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4470 short_channel_id: 2,
4473 cltv_expiry_delta: 0,
4474 htlc_minimum_msat: 0,
4475 htlc_maximum_msat: 100_000,
4477 fee_proportional_millionths: 0,
4478 excess_data: Vec::new()
4480 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4481 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4482 short_channel_id: 7,
4485 cltv_expiry_delta: 0,
4486 htlc_minimum_msat: 0,
4487 htlc_maximum_msat: 100_000,
4489 fee_proportional_millionths: 0,
4490 excess_data: Vec::new()
4493 // Path via {node0, node2} is channels {1, 3, 5}.
4494 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4495 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4496 short_channel_id: 1,
4499 cltv_expiry_delta: 0,
4500 htlc_minimum_msat: 0,
4501 htlc_maximum_msat: 100_000,
4503 fee_proportional_millionths: 0,
4504 excess_data: Vec::new()
4506 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4507 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4508 short_channel_id: 3,
4511 cltv_expiry_delta: 0,
4512 htlc_minimum_msat: 0,
4513 htlc_maximum_msat: 100_000,
4515 fee_proportional_millionths: 0,
4516 excess_data: Vec::new()
4519 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4520 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4521 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4522 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4523 short_channel_id: 5,
4526 cltv_expiry_delta: 0,
4527 htlc_minimum_msat: 0,
4528 htlc_maximum_msat: 200_000,
4530 fee_proportional_millionths: 0,
4531 excess_data: Vec::new()
4534 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4535 // Add 100 sats to the capacities of {12, 13}, because these channels
4536 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4537 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4538 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4539 short_channel_id: 12,
4542 cltv_expiry_delta: 0,
4543 htlc_minimum_msat: 0,
4544 htlc_maximum_msat: 200_000,
4546 fee_proportional_millionths: 0,
4547 excess_data: Vec::new()
4549 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4550 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4551 short_channel_id: 13,
4554 cltv_expiry_delta: 0,
4555 htlc_minimum_msat: 0,
4556 htlc_maximum_msat: 200_000,
4558 fee_proportional_millionths: 0,
4559 excess_data: Vec::new()
4562 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4563 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4564 short_channel_id: 6,
4567 cltv_expiry_delta: 0,
4568 htlc_minimum_msat: 0,
4569 htlc_maximum_msat: 100_000,
4570 fee_base_msat: 1_000,
4571 fee_proportional_millionths: 0,
4572 excess_data: Vec::new()
4574 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4575 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4576 short_channel_id: 11,
4579 cltv_expiry_delta: 0,
4580 htlc_minimum_msat: 0,
4581 htlc_maximum_msat: 100_000,
4583 fee_proportional_millionths: 0,
4584 excess_data: Vec::new()
4587 // Path via {node7, node2} is channels {12, 13, 5}.
4588 // We already limited them to 200 sats (they are used twice for 100 sats).
4589 // Nothing to do here.
4592 // Now, attempt to route 180 sats.
4593 // Our algorithm should provide us with these 2 paths.
4594 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4595 assert_eq!(route.paths.len(), 2);
4597 let mut total_value_transferred_msat = 0;
4598 let mut total_paid_msat = 0;
4599 for path in &route.paths {
4600 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4601 total_value_transferred_msat += path.final_value_msat();
4602 for hop in &path.hops {
4603 total_paid_msat += hop.fee_msat;
4606 // If we paid fee, this would be higher.
4607 assert_eq!(total_value_transferred_msat, 180_000);
4608 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4609 assert_eq!(total_fees_paid, 0);
4614 fn fees_on_mpp_route_test() {
4615 // This test makes sure that MPP algorithm properly takes into account
4616 // fees charged on the channels, by making the fees impactful:
4617 // if the fee is not properly accounted for, the behavior is different.
4618 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4619 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4620 let scorer = ln_test_utils::TestScorer::new();
4621 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4622 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4623 let config = UserConfig::default();
4624 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4626 // We need a route consisting of 2 paths:
4627 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4628 // We will route 200 sats, Each path will have 100 sats capacity.
4630 // This test is not particularly stable: e.g.,
4631 // there's a way to route via {node0, node2, node4}.
4632 // It works while pathfinding is deterministic, but can be broken otherwise.
4633 // It's fine to ignore this concern for now.
4635 // Disable other potential paths.
4636 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4637 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4638 short_channel_id: 2,
4641 cltv_expiry_delta: 0,
4642 htlc_minimum_msat: 0,
4643 htlc_maximum_msat: 100_000,
4645 fee_proportional_millionths: 0,
4646 excess_data: Vec::new()
4649 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4650 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4651 short_channel_id: 7,
4654 cltv_expiry_delta: 0,
4655 htlc_minimum_msat: 0,
4656 htlc_maximum_msat: 100_000,
4658 fee_proportional_millionths: 0,
4659 excess_data: Vec::new()
4662 // Path via {node0, node2} is channels {1, 3, 5}.
4663 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4664 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4665 short_channel_id: 1,
4668 cltv_expiry_delta: 0,
4669 htlc_minimum_msat: 0,
4670 htlc_maximum_msat: 100_000,
4672 fee_proportional_millionths: 0,
4673 excess_data: Vec::new()
4675 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4676 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4677 short_channel_id: 3,
4680 cltv_expiry_delta: 0,
4681 htlc_minimum_msat: 0,
4682 htlc_maximum_msat: 100_000,
4684 fee_proportional_millionths: 0,
4685 excess_data: Vec::new()
4688 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4689 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4690 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4691 short_channel_id: 5,
4694 cltv_expiry_delta: 0,
4695 htlc_minimum_msat: 0,
4696 htlc_maximum_msat: 100_000,
4698 fee_proportional_millionths: 0,
4699 excess_data: Vec::new()
4702 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4703 // All channels should be 100 sats capacity. But for the fee experiment,
4704 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4705 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4706 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4707 // so no matter how large are other channels,
4708 // the whole path will be limited by 100 sats with just these 2 conditions:
4709 // - channel 12 capacity is 250 sats
4710 // - fee for channel 6 is 150 sats
4711 // Let's test this by enforcing these 2 conditions and removing other limits.
4712 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4713 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4714 short_channel_id: 12,
4717 cltv_expiry_delta: 0,
4718 htlc_minimum_msat: 0,
4719 htlc_maximum_msat: 250_000,
4721 fee_proportional_millionths: 0,
4722 excess_data: Vec::new()
4724 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4725 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4726 short_channel_id: 13,
4729 cltv_expiry_delta: 0,
4730 htlc_minimum_msat: 0,
4731 htlc_maximum_msat: MAX_VALUE_MSAT,
4733 fee_proportional_millionths: 0,
4734 excess_data: Vec::new()
4737 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4739 short_channel_id: 6,
4742 cltv_expiry_delta: 0,
4743 htlc_minimum_msat: 0,
4744 htlc_maximum_msat: MAX_VALUE_MSAT,
4745 fee_base_msat: 150_000,
4746 fee_proportional_millionths: 0,
4747 excess_data: Vec::new()
4749 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4750 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4751 short_channel_id: 11,
4754 cltv_expiry_delta: 0,
4755 htlc_minimum_msat: 0,
4756 htlc_maximum_msat: MAX_VALUE_MSAT,
4758 fee_proportional_millionths: 0,
4759 excess_data: Vec::new()
4763 // Attempt to route more than available results in a failure.
4764 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4765 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4766 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4767 } else { panic!(); }
4771 // Now, attempt to route 200 sats (exact amount we can route).
4772 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4773 assert_eq!(route.paths.len(), 2);
4775 let mut total_amount_paid_msat = 0;
4776 for path in &route.paths {
4777 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4778 total_amount_paid_msat += path.final_value_msat();
4780 assert_eq!(total_amount_paid_msat, 200_000);
4781 assert_eq!(route.get_total_fees(), 150_000);
4786 fn mpp_with_last_hops() {
4787 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4788 // via a single last-hop route hint, we'd fail to route if we first collected routes
4789 // totaling close but not quite enough to fund the full payment.
4791 // This was because we considered last-hop hints to have exactly the sought payment amount
4792 // instead of the amount we were trying to collect, needlessly limiting our path searching
4793 // at the very first hop.
4795 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4796 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4797 // to only have the remaining to-collect amount in available liquidity.
4799 // This bug appeared in production in some specific channel configurations.
4800 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4801 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4802 let scorer = ln_test_utils::TestScorer::new();
4803 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4804 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4805 let config = UserConfig::default();
4806 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
4807 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4808 src_node_id: nodes[2],
4809 short_channel_id: 42,
4810 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4811 cltv_expiry_delta: 42,
4812 htlc_minimum_msat: None,
4813 htlc_maximum_msat: None,
4814 }])]).unwrap().with_max_channel_saturation_power_of_half(0);
4816 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4817 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4818 // would first use the no-fee route and then fail to find a path along the second route as
4819 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4820 // under 5% of our payment amount.
4821 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4822 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4823 short_channel_id: 1,
4826 cltv_expiry_delta: (5 << 4) | 5,
4827 htlc_minimum_msat: 0,
4828 htlc_maximum_msat: 99_000,
4829 fee_base_msat: u32::max_value(),
4830 fee_proportional_millionths: u32::max_value(),
4831 excess_data: Vec::new()
4833 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4834 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4835 short_channel_id: 2,
4838 cltv_expiry_delta: (5 << 4) | 3,
4839 htlc_minimum_msat: 0,
4840 htlc_maximum_msat: 99_000,
4841 fee_base_msat: u32::max_value(),
4842 fee_proportional_millionths: u32::max_value(),
4843 excess_data: Vec::new()
4845 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4846 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4847 short_channel_id: 4,
4850 cltv_expiry_delta: (4 << 4) | 1,
4851 htlc_minimum_msat: 0,
4852 htlc_maximum_msat: MAX_VALUE_MSAT,
4854 fee_proportional_millionths: 0,
4855 excess_data: Vec::new()
4857 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4858 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4859 short_channel_id: 13,
4861 flags: 0|2, // Channel disabled
4862 cltv_expiry_delta: (13 << 4) | 1,
4863 htlc_minimum_msat: 0,
4864 htlc_maximum_msat: MAX_VALUE_MSAT,
4866 fee_proportional_millionths: 2000000,
4867 excess_data: Vec::new()
4870 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4872 let mut route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4873 assert_eq!(route.paths.len(), 2);
4874 route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
4875 // Paths are manually ordered ordered by SCID, so:
4876 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4877 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
4878 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
4879 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
4880 assert_eq!(route.paths[0].hops[2].fee_msat, 99_000);
4881 assert_eq!(route.paths[1].hops[0].short_channel_id, 2);
4882 assert_eq!(route.paths[1].hops[0].fee_msat, 1);
4883 assert_eq!(route.paths[1].hops[2].fee_msat, 1_000);
4884 assert_eq!(route.get_total_fees(), 1);
4885 assert_eq!(route.get_total_amount(), 100_000);
4889 fn drop_lowest_channel_mpp_route_test() {
4890 // This test checks that low-capacity channel is dropped when after
4891 // path finding we realize that we found more capacity than we need.
4892 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4893 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4894 let scorer = ln_test_utils::TestScorer::new();
4895 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4896 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4897 let config = UserConfig::default();
4898 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
4899 .with_max_channel_saturation_power_of_half(0);
4901 // We need a route consisting of 3 paths:
4902 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4904 // The first and the second paths should be sufficient, but the third should be
4905 // cheaper, so that we select it but drop later.
4907 // First, we set limits on these (previously unlimited) channels.
4908 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4910 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4911 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4912 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4913 short_channel_id: 1,
4916 cltv_expiry_delta: 0,
4917 htlc_minimum_msat: 0,
4918 htlc_maximum_msat: 100_000,
4920 fee_proportional_millionths: 0,
4921 excess_data: Vec::new()
4923 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4924 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4925 short_channel_id: 3,
4928 cltv_expiry_delta: 0,
4929 htlc_minimum_msat: 0,
4930 htlc_maximum_msat: 50_000,
4932 fee_proportional_millionths: 0,
4933 excess_data: Vec::new()
4936 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4937 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4938 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4939 short_channel_id: 12,
4942 cltv_expiry_delta: 0,
4943 htlc_minimum_msat: 0,
4944 htlc_maximum_msat: 60_000,
4946 fee_proportional_millionths: 0,
4947 excess_data: Vec::new()
4949 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4950 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4951 short_channel_id: 13,
4954 cltv_expiry_delta: 0,
4955 htlc_minimum_msat: 0,
4956 htlc_maximum_msat: 60_000,
4958 fee_proportional_millionths: 0,
4959 excess_data: Vec::new()
4962 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4963 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4964 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4965 short_channel_id: 2,
4968 cltv_expiry_delta: 0,
4969 htlc_minimum_msat: 0,
4970 htlc_maximum_msat: 20_000,
4972 fee_proportional_millionths: 0,
4973 excess_data: Vec::new()
4975 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4976 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4977 short_channel_id: 4,
4980 cltv_expiry_delta: 0,
4981 htlc_minimum_msat: 0,
4982 htlc_maximum_msat: 20_000,
4984 fee_proportional_millionths: 0,
4985 excess_data: Vec::new()
4989 // Attempt to route more than available results in a failure.
4990 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4991 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4992 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4993 } else { panic!(); }
4997 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4998 // Our algorithm should provide us with these 3 paths.
4999 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5000 assert_eq!(route.paths.len(), 3);
5001 let mut total_amount_paid_msat = 0;
5002 for path in &route.paths {
5003 assert_eq!(path.hops.len(), 2);
5004 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5005 total_amount_paid_msat += path.final_value_msat();
5007 assert_eq!(total_amount_paid_msat, 125_000);
5011 // Attempt to route without the last small cheap channel
5012 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5013 assert_eq!(route.paths.len(), 2);
5014 let mut total_amount_paid_msat = 0;
5015 for path in &route.paths {
5016 assert_eq!(path.hops.len(), 2);
5017 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5018 total_amount_paid_msat += path.final_value_msat();
5020 assert_eq!(total_amount_paid_msat, 90_000);
5025 fn min_criteria_consistency() {
5026 // Test that we don't use an inconsistent metric between updating and walking nodes during
5027 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
5028 // was updated with a different criterion from the heap sorting, resulting in loops in
5029 // calculated paths. We test for that specific case here.
5031 // We construct a network that looks like this:
5033 // node2 -1(3)2- node3
5037 // node1 -1(5)2- node4 -1(1)2- node6
5043 // We create a loop on the side of our real path - our destination is node 6, with a
5044 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
5045 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
5046 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
5047 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
5048 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
5049 // "previous hop" being set to node 3, creating a loop in the path.
5050 let secp_ctx = Secp256k1::new();
5051 let logger = Arc::new(ln_test_utils::TestLogger::new());
5052 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
5053 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
5054 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5055 let scorer = ln_test_utils::TestScorer::new();
5056 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5057 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5058 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
5060 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
5061 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5062 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5063 short_channel_id: 6,
5066 cltv_expiry_delta: (6 << 4) | 0,
5067 htlc_minimum_msat: 0,
5068 htlc_maximum_msat: MAX_VALUE_MSAT,
5070 fee_proportional_millionths: 0,
5071 excess_data: Vec::new()
5073 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
5075 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5076 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5077 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5078 short_channel_id: 5,
5081 cltv_expiry_delta: (5 << 4) | 0,
5082 htlc_minimum_msat: 0,
5083 htlc_maximum_msat: MAX_VALUE_MSAT,
5085 fee_proportional_millionths: 0,
5086 excess_data: Vec::new()
5088 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
5090 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
5091 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5092 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5093 short_channel_id: 4,
5096 cltv_expiry_delta: (4 << 4) | 0,
5097 htlc_minimum_msat: 0,
5098 htlc_maximum_msat: MAX_VALUE_MSAT,
5100 fee_proportional_millionths: 0,
5101 excess_data: Vec::new()
5103 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
5105 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
5106 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5107 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5108 short_channel_id: 3,
5111 cltv_expiry_delta: (3 << 4) | 0,
5112 htlc_minimum_msat: 0,
5113 htlc_maximum_msat: MAX_VALUE_MSAT,
5115 fee_proportional_millionths: 0,
5116 excess_data: Vec::new()
5118 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
5120 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
5121 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5122 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5123 short_channel_id: 2,
5126 cltv_expiry_delta: (2 << 4) | 0,
5127 htlc_minimum_msat: 0,
5128 htlc_maximum_msat: MAX_VALUE_MSAT,
5130 fee_proportional_millionths: 0,
5131 excess_data: Vec::new()
5134 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
5135 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5136 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5137 short_channel_id: 1,
5140 cltv_expiry_delta: (1 << 4) | 0,
5141 htlc_minimum_msat: 100,
5142 htlc_maximum_msat: MAX_VALUE_MSAT,
5144 fee_proportional_millionths: 0,
5145 excess_data: Vec::new()
5147 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
5150 // Now ensure the route flows simply over nodes 1 and 4 to 6.
5151 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5152 assert_eq!(route.paths.len(), 1);
5153 assert_eq!(route.paths[0].hops.len(), 3);
5155 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
5156 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5157 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
5158 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (5 << 4) | 0);
5159 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(1));
5160 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(6));
5162 assert_eq!(route.paths[0].hops[1].pubkey, nodes[4]);
5163 assert_eq!(route.paths[0].hops[1].short_channel_id, 5);
5164 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
5165 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (1 << 4) | 0);
5166 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(4));
5167 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(5));
5169 assert_eq!(route.paths[0].hops[2].pubkey, nodes[6]);
5170 assert_eq!(route.paths[0].hops[2].short_channel_id, 1);
5171 assert_eq!(route.paths[0].hops[2].fee_msat, 10_000);
5172 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
5173 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
5174 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(1));
5180 fn exact_fee_liquidity_limit() {
5181 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5182 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5183 // we calculated fees on a higher value, resulting in us ignoring such paths.
5184 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5185 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5186 let scorer = ln_test_utils::TestScorer::new();
5187 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5188 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5189 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
5191 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5193 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5194 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5195 short_channel_id: 2,
5198 cltv_expiry_delta: 0,
5199 htlc_minimum_msat: 0,
5200 htlc_maximum_msat: 85_000,
5202 fee_proportional_millionths: 0,
5203 excess_data: Vec::new()
5206 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5207 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5208 short_channel_id: 12,
5211 cltv_expiry_delta: (4 << 4) | 1,
5212 htlc_minimum_msat: 0,
5213 htlc_maximum_msat: 270_000,
5215 fee_proportional_millionths: 1000000,
5216 excess_data: Vec::new()
5220 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5221 // 200% fee charged channel 13 in the 1-to-2 direction.
5222 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5223 assert_eq!(route.paths.len(), 1);
5224 assert_eq!(route.paths[0].hops.len(), 2);
5226 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5227 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5228 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5229 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5230 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5231 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5233 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5234 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5235 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5236 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5237 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
5238 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5243 fn htlc_max_reduction_below_min() {
5244 // Test that if, while walking the graph, we reduce the value being sent to meet an
5245 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5246 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5247 // resulting in us thinking there is no possible path, even if other paths exist.
5248 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5249 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5250 let scorer = ln_test_utils::TestScorer::new();
5251 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5252 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5253 let config = UserConfig::default();
5254 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5256 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5257 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5258 // then try to send 90_000.
5259 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5260 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5261 short_channel_id: 2,
5264 cltv_expiry_delta: 0,
5265 htlc_minimum_msat: 0,
5266 htlc_maximum_msat: 80_000,
5268 fee_proportional_millionths: 0,
5269 excess_data: Vec::new()
5271 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5272 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5273 short_channel_id: 4,
5276 cltv_expiry_delta: (4 << 4) | 1,
5277 htlc_minimum_msat: 90_000,
5278 htlc_maximum_msat: MAX_VALUE_MSAT,
5280 fee_proportional_millionths: 0,
5281 excess_data: Vec::new()
5285 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5286 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5287 // expensive) channels 12-13 path.
5288 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5289 assert_eq!(route.paths.len(), 1);
5290 assert_eq!(route.paths[0].hops.len(), 2);
5292 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5293 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5294 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5295 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5296 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5297 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5299 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5300 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5301 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5302 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5303 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), channelmanager::provided_invoice_features(&config).le_flags());
5304 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5309 fn multiple_direct_first_hops() {
5310 // Previously we'd only ever considered one first hop path per counterparty.
5311 // However, as we don't restrict users to one channel per peer, we really need to support
5312 // looking at all first hop paths.
5313 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5314 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5315 // route over multiple channels with the same first hop.
5316 let secp_ctx = Secp256k1::new();
5317 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5318 let logger = Arc::new(ln_test_utils::TestLogger::new());
5319 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
5320 let scorer = ln_test_utils::TestScorer::new();
5321 let config = UserConfig::default();
5322 let payment_params = PaymentParameters::from_node_id(nodes[0], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5323 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5324 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5327 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5328 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
5329 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
5330 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5331 assert_eq!(route.paths.len(), 1);
5332 assert_eq!(route.paths[0].hops.len(), 1);
5334 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5335 assert_eq!(route.paths[0].hops[0].short_channel_id, 3);
5336 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5339 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5340 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5341 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5342 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5343 assert_eq!(route.paths.len(), 2);
5344 assert_eq!(route.paths[0].hops.len(), 1);
5345 assert_eq!(route.paths[1].hops.len(), 1);
5347 assert!((route.paths[0].hops[0].short_channel_id == 3 && route.paths[1].hops[0].short_channel_id == 2) ||
5348 (route.paths[0].hops[0].short_channel_id == 2 && route.paths[1].hops[0].short_channel_id == 3));
5350 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5351 assert_eq!(route.paths[0].hops[0].fee_msat, 50_000);
5353 assert_eq!(route.paths[1].hops[0].pubkey, nodes[0]);
5354 assert_eq!(route.paths[1].hops[0].fee_msat, 50_000);
5358 // If we have a bunch of outbound channels to the same node, where most are not
5359 // sufficient to pay the full payment, but one is, we should default to just using the
5360 // one single channel that has sufficient balance, avoiding MPP.
5362 // If we have several options above the 3xpayment value threshold, we should pick the
5363 // smallest of them, avoiding further fragmenting our available outbound balance to
5365 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5366 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5367 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5368 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5369 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
5370 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5371 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5372 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5373 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
5374 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5375 assert_eq!(route.paths.len(), 1);
5376 assert_eq!(route.paths[0].hops.len(), 1);
5378 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5379 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5380 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5385 fn prefers_shorter_route_with_higher_fees() {
5386 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5387 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5388 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5390 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5391 let scorer = ln_test_utils::TestScorer::new();
5392 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5393 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5394 let route = get_route(
5395 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5396 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5398 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5400 assert_eq!(route.get_total_fees(), 100);
5401 assert_eq!(route.get_total_amount(), 100);
5402 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5404 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5405 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5406 let scorer = FixedPenaltyScorer::with_penalty(100);
5407 let route = get_route(
5408 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5409 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5411 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5413 assert_eq!(route.get_total_fees(), 300);
5414 assert_eq!(route.get_total_amount(), 100);
5415 assert_eq!(path, vec![2, 4, 7, 10]);
5418 struct BadChannelScorer {
5419 short_channel_id: u64,
5423 impl Writeable for BadChannelScorer {
5424 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5426 impl Score for BadChannelScorer {
5427 type ScoreParams = ();
5428 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5429 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5432 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5433 fn payment_path_successful(&mut self, _path: &Path) {}
5434 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5435 fn probe_successful(&mut self, _path: &Path) {}
5438 struct BadNodeScorer {
5443 impl Writeable for BadNodeScorer {
5444 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5447 impl Score for BadNodeScorer {
5448 type ScoreParams = ();
5449 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5450 if *target == self.node_id { u64::max_value() } else { 0 }
5453 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5454 fn payment_path_successful(&mut self, _path: &Path) {}
5455 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5456 fn probe_successful(&mut self, _path: &Path) {}
5460 fn avoids_routing_through_bad_channels_and_nodes() {
5461 let (secp_ctx, network, _, _, logger) = build_graph();
5462 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5463 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5464 let network_graph = network.read_only();
5466 // A path to nodes[6] exists when no penalties are applied to any channel.
5467 let scorer = ln_test_utils::TestScorer::new();
5468 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5469 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5470 let route = get_route(
5471 &our_id, &payment_params, &network_graph, None, 100,
5472 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5474 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5476 assert_eq!(route.get_total_fees(), 100);
5477 assert_eq!(route.get_total_amount(), 100);
5478 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5480 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5481 let scorer = BadChannelScorer { short_channel_id: 6 };
5482 let route = get_route(
5483 &our_id, &payment_params, &network_graph, None, 100,
5484 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5486 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5488 assert_eq!(route.get_total_fees(), 300);
5489 assert_eq!(route.get_total_amount(), 100);
5490 assert_eq!(path, vec![2, 4, 7, 10]);
5492 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5493 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5495 &our_id, &payment_params, &network_graph, None, 100,
5496 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5498 Err(LightningError { err, .. } ) => {
5499 assert_eq!(err, "Failed to find a path to the given destination");
5501 Ok(_) => panic!("Expected error"),
5506 fn total_fees_single_path() {
5508 paths: vec![Path { hops: vec![
5510 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5511 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5512 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5515 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5516 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5517 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5520 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5521 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5522 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5524 ], blinded_tail: None }],
5525 payment_params: None,
5528 assert_eq!(route.get_total_fees(), 250);
5529 assert_eq!(route.get_total_amount(), 225);
5533 fn total_fees_multi_path() {
5535 paths: vec![Path { hops: vec![
5537 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5538 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5539 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5542 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5543 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5544 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5546 ], blinded_tail: None }, Path { hops: vec![
5548 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5549 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5550 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5553 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5554 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5555 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5557 ], blinded_tail: None }],
5558 payment_params: None,
5561 assert_eq!(route.get_total_fees(), 200);
5562 assert_eq!(route.get_total_amount(), 300);
5566 fn total_empty_route_no_panic() {
5567 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5568 // would both panic if the route was completely empty. We test to ensure they return 0
5569 // here, even though its somewhat nonsensical as a route.
5570 let route = Route { paths: Vec::new(), payment_params: None };
5572 assert_eq!(route.get_total_fees(), 0);
5573 assert_eq!(route.get_total_amount(), 0);
5577 fn limits_total_cltv_delta() {
5578 let (secp_ctx, network, _, _, logger) = build_graph();
5579 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5580 let network_graph = network.read_only();
5582 let scorer = ln_test_utils::TestScorer::new();
5584 // Make sure that generally there is at least one route available
5585 let feasible_max_total_cltv_delta = 1008;
5586 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5587 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5588 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5589 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5590 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5591 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5592 assert_ne!(path.len(), 0);
5594 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5595 let fail_max_total_cltv_delta = 23;
5596 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5597 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5598 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5600 Err(LightningError { err, .. } ) => {
5601 assert_eq!(err, "Failed to find a path to the given destination");
5603 Ok(_) => panic!("Expected error"),
5608 fn avoids_recently_failed_paths() {
5609 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
5610 // randomly inserting channels into it until we can't find a route anymore.
5611 let (secp_ctx, network, _, _, logger) = build_graph();
5612 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5613 let network_graph = network.read_only();
5615 let scorer = ln_test_utils::TestScorer::new();
5616 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5617 .with_max_path_count(1);
5618 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5619 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5621 // We should be able to find a route initially, and then after we fail a few random
5622 // channels eventually we won't be able to any longer.
5623 assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).is_ok());
5625 if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
5626 for chan in route.paths[0].hops.iter() {
5627 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
5629 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
5630 % route.paths[0].hops.len();
5631 payment_params.previously_failed_channels.push(route.paths[0].hops[victim].short_channel_id);
5637 fn limits_path_length() {
5638 let (secp_ctx, network, _, _, logger) = build_line_graph();
5639 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5640 let network_graph = network.read_only();
5642 let scorer = ln_test_utils::TestScorer::new();
5643 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5644 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5646 // First check we can actually create a long route on this graph.
5647 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
5648 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100,
5649 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5650 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5651 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5653 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5654 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
5655 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100,
5656 Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5658 Err(LightningError { err, .. } ) => {
5659 assert_eq!(err, "Failed to find a path to the given destination");
5661 Ok(_) => panic!("Expected error"),
5666 fn adds_and_limits_cltv_offset() {
5667 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5668 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5670 let scorer = ln_test_utils::TestScorer::new();
5672 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5673 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5674 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5675 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5676 assert_eq!(route.paths.len(), 1);
5678 let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5680 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5681 let mut route_default = route.clone();
5682 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5683 let cltv_expiry_deltas_default = route_default.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5684 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5685 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5686 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5688 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5689 let mut route_limited = route.clone();
5690 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5691 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5692 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5693 let cltv_expiry_deltas_limited = route_limited.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5694 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5698 fn adds_plausible_cltv_offset() {
5699 let (secp_ctx, network, _, _, logger) = build_graph();
5700 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5701 let network_graph = network.read_only();
5702 let network_nodes = network_graph.nodes();
5703 let network_channels = network_graph.channels();
5704 let scorer = ln_test_utils::TestScorer::new();
5705 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5706 let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5707 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5709 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100,
5710 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5711 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5713 let mut path_plausibility = vec![];
5715 for p in route.paths {
5716 // 1. Select random observation point
5717 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5718 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5720 prng.process_in_place(&mut random_bytes);
5721 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.hops.len());
5722 let observation_point = NodeId::from_pubkey(&p.hops.get(random_path_index).unwrap().pubkey);
5724 // 2. Calculate what CLTV expiry delta we would observe there
5725 let observed_cltv_expiry_delta: u32 = p.hops[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5727 // 3. Starting from the observation point, find candidate paths
5728 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5729 candidates.push_back((observation_point, vec![]));
5731 let mut found_plausible_candidate = false;
5733 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5734 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5735 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5736 found_plausible_candidate = true;
5737 break 'candidate_loop;
5741 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5742 for channel_id in &cur_node.channels {
5743 if let Some(channel_info) = network_channels.get(&channel_id) {
5744 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5745 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
5746 if cur_path_cltv_deltas.iter().sum::<u32>()
5747 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5748 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5749 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5750 candidates.push_back((*next_id, new_path_cltv_deltas));
5758 path_plausibility.push(found_plausible_candidate);
5760 assert!(path_plausibility.iter().all(|x| *x));
5764 fn builds_correct_path_from_hops() {
5765 let (secp_ctx, network, _, _, logger) = build_graph();
5766 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5767 let network_graph = network.read_only();
5769 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5770 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5772 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5773 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5774 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5775 &network_graph, 100, Arc::clone(&logger), &random_seed_bytes).unwrap();
5776 let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5777 assert_eq!(hops.len(), route.paths[0].hops.len());
5778 for (idx, hop_pubkey) in hops.iter().enumerate() {
5779 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5784 fn avoids_saturating_channels() {
5785 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5786 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5787 let decay_params = ProbabilisticScoringDecayParameters::default();
5788 let scorer = ProbabilisticScorer::new(decay_params, &*network_graph, Arc::clone(&logger));
5790 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
5791 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
5792 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5793 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5794 short_channel_id: 4,
5797 cltv_expiry_delta: (4 << 4) | 1,
5798 htlc_minimum_msat: 0,
5799 htlc_maximum_msat: 250_000_000,
5801 fee_proportional_millionths: 0,
5802 excess_data: Vec::new()
5804 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5805 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5806 short_channel_id: 13,
5809 cltv_expiry_delta: (13 << 4) | 1,
5810 htlc_minimum_msat: 0,
5811 htlc_maximum_msat: 250_000_000,
5813 fee_proportional_millionths: 0,
5814 excess_data: Vec::new()
5817 let config = UserConfig::default();
5818 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5819 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5820 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5821 // 100,000 sats is less than the available liquidity on each channel, set above.
5822 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000_000, Arc::clone(&logger), &scorer, &ProbabilisticScoringFeeParameters::default(), &random_seed_bytes).unwrap();
5823 assert_eq!(route.paths.len(), 2);
5824 assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
5825 (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
5828 #[cfg(not(feature = "no-std"))]
5829 pub(super) fn random_init_seed() -> u64 {
5830 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5831 use core::hash::{BuildHasher, Hasher};
5832 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5833 println!("Using seed of {}", seed);
5838 #[cfg(not(feature = "no-std"))]
5839 fn generate_routes() {
5840 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
5842 let logger = ln_test_utils::TestLogger::new();
5843 let graph = match super::bench_utils::read_network_graph(&logger) {
5851 let params = ProbabilisticScoringFeeParameters::default();
5852 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
5853 let features = super::InvoiceFeatures::empty();
5855 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
5859 #[cfg(not(feature = "no-std"))]
5860 fn generate_routes_mpp() {
5861 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
5863 let logger = ln_test_utils::TestLogger::new();
5864 let graph = match super::bench_utils::read_network_graph(&logger) {
5872 let params = ProbabilisticScoringFeeParameters::default();
5873 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
5874 let features = channelmanager::provided_invoice_features(&UserConfig::default());
5876 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
5880 #[cfg(not(feature = "no-std"))]
5881 fn generate_large_mpp_routes() {
5882 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
5884 let logger = ln_test_utils::TestLogger::new();
5885 let graph = match super::bench_utils::read_network_graph(&logger) {
5893 let params = ProbabilisticScoringFeeParameters::default();
5894 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
5895 let features = channelmanager::provided_invoice_features(&UserConfig::default());
5897 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 1_000_000, 2);
5901 fn honors_manual_penalties() {
5902 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
5903 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5905 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5906 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5908 let mut scorer_params = ProbabilisticScoringFeeParameters::default();
5909 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), Arc::clone(&network_graph), Arc::clone(&logger));
5911 // First check set manual penalties are returned by the scorer.
5912 let usage = ChannelUsage {
5914 inflight_htlc_msat: 0,
5915 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
5917 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
5918 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
5919 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage, &scorer_params), 456);
5921 // Then check we can get a normal route
5922 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
5923 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5924 assert!(route.is_ok());
5926 // Then check that we can't get a route if we ban an intermediate node.
5927 scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3]));
5928 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5929 assert!(route.is_err());
5931 // Finally make sure we can route again, when we remove the ban.
5932 scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3]));
5933 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5934 assert!(route.is_ok());
5938 fn abide_by_route_hint_max_htlc() {
5939 // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
5940 // params in the final route.
5941 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5942 let netgraph = network_graph.read_only();
5943 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5944 let scorer = ln_test_utils::TestScorer::new();
5945 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5946 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5947 let config = UserConfig::default();
5949 let max_htlc_msat = 50_000;
5950 let route_hint_1 = RouteHint(vec![RouteHintHop {
5951 src_node_id: nodes[2],
5952 short_channel_id: 42,
5955 proportional_millionths: 0,
5957 cltv_expiry_delta: 10,
5958 htlc_minimum_msat: None,
5959 htlc_maximum_msat: Some(max_htlc_msat),
5961 let dest_node_id = ln_test_utils::pubkey(42);
5962 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
5963 .with_route_hints(vec![route_hint_1.clone()]).unwrap()
5964 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5966 // Make sure we'll error if our route hints don't have enough liquidity according to their
5967 // htlc_maximum_msat.
5968 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
5969 &payment_params, &netgraph, None, max_htlc_msat + 1, Arc::clone(&logger), &scorer, &(),
5972 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5973 } else { panic!(); }
5975 // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
5976 let mut route_hint_2 = route_hint_1.clone();
5977 route_hint_2.0[0].short_channel_id = 43;
5978 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
5979 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
5980 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5981 let route = get_route(&our_id, &payment_params, &netgraph, None, max_htlc_msat + 1,
5982 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5983 assert_eq!(route.paths.len(), 2);
5984 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
5985 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
5989 fn direct_channel_to_hints_with_max_htlc() {
5990 // Check that if we have a first hop channel peer that's connected to multiple provided route
5991 // hints, that we properly split the payment between the route hints if needed.
5992 let logger = Arc::new(ln_test_utils::TestLogger::new());
5993 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
5994 let scorer = ln_test_utils::TestScorer::new();
5995 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5996 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5997 let config = UserConfig::default();
5999 let our_node_id = ln_test_utils::pubkey(42);
6000 let intermed_node_id = ln_test_utils::pubkey(43);
6001 let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
6003 let amt_msat = 900_000;
6004 let max_htlc_msat = 500_000;
6005 let route_hint_1 = RouteHint(vec![RouteHintHop {
6006 src_node_id: intermed_node_id,
6007 short_channel_id: 44,
6010 proportional_millionths: 0,
6012 cltv_expiry_delta: 10,
6013 htlc_minimum_msat: None,
6014 htlc_maximum_msat: Some(max_htlc_msat),
6016 src_node_id: intermed_node_id,
6017 short_channel_id: 45,
6020 proportional_millionths: 0,
6022 cltv_expiry_delta: 10,
6023 htlc_minimum_msat: None,
6024 // Check that later route hint max htlcs don't override earlier ones
6025 htlc_maximum_msat: Some(max_htlc_msat - 50),
6027 let mut route_hint_2 = route_hint_1.clone();
6028 route_hint_2.0[0].short_channel_id = 46;
6029 route_hint_2.0[1].short_channel_id = 47;
6030 let dest_node_id = ln_test_utils::pubkey(44);
6031 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
6032 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
6033 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6035 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6036 Some(&first_hop.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6037 &random_seed_bytes).unwrap();
6038 assert_eq!(route.paths.len(), 2);
6039 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6040 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6041 assert_eq!(route.get_total_amount(), amt_msat);
6043 // Re-run but with two first hop channels connected to the same route hint peers that must be
6045 let first_hops = vec![
6046 get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6047 get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6049 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6050 Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6051 &random_seed_bytes).unwrap();
6052 assert_eq!(route.paths.len(), 2);
6053 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6054 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6055 assert_eq!(route.get_total_amount(), amt_msat);
6059 fn blinded_route_ser() {
6060 let blinded_path_1 = BlindedPath {
6061 introduction_node_id: ln_test_utils::pubkey(42),
6062 blinding_point: ln_test_utils::pubkey(43),
6064 BlindedHop { blinded_node_id: ln_test_utils::pubkey(44), encrypted_payload: Vec::new() },
6065 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() }
6068 let blinded_path_2 = BlindedPath {
6069 introduction_node_id: ln_test_utils::pubkey(46),
6070 blinding_point: ln_test_utils::pubkey(47),
6072 BlindedHop { blinded_node_id: ln_test_utils::pubkey(48), encrypted_payload: Vec::new() },
6073 BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }
6076 // (De)serialize a Route with 1 blinded path out of two total paths.
6077 let mut route = Route { paths: vec![Path {
6078 hops: vec![RouteHop {
6079 pubkey: ln_test_utils::pubkey(50),
6080 node_features: NodeFeatures::empty(),
6081 short_channel_id: 42,
6082 channel_features: ChannelFeatures::empty(),
6084 cltv_expiry_delta: 0,
6086 blinded_tail: Some(BlindedTail {
6087 hops: blinded_path_1.blinded_hops,
6088 blinding_point: blinded_path_1.blinding_point,
6089 excess_final_cltv_expiry_delta: 40,
6090 final_value_msat: 100,
6092 hops: vec![RouteHop {
6093 pubkey: ln_test_utils::pubkey(51),
6094 node_features: NodeFeatures::empty(),
6095 short_channel_id: 43,
6096 channel_features: ChannelFeatures::empty(),
6098 cltv_expiry_delta: 0,
6099 }], blinded_tail: None }],
6100 payment_params: None,
6102 let encoded_route = route.encode();
6103 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6104 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6105 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6107 // (De)serialize a Route with two paths, each containing a blinded tail.
6108 route.paths[1].blinded_tail = Some(BlindedTail {
6109 hops: blinded_path_2.blinded_hops,
6110 blinding_point: blinded_path_2.blinding_point,
6111 excess_final_cltv_expiry_delta: 41,
6112 final_value_msat: 101,
6114 let encoded_route = route.encode();
6115 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6116 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6117 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6121 fn blinded_path_inflight_processing() {
6122 // Ensure we'll score the channel that's inbound to a blinded path's introduction node, and
6123 // account for the blinded tail's final amount_msat.
6124 let mut inflight_htlcs = InFlightHtlcs::new();
6125 let blinded_path = BlindedPath {
6126 introduction_node_id: ln_test_utils::pubkey(43),
6127 blinding_point: ln_test_utils::pubkey(48),
6128 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }],
6131 hops: vec![RouteHop {
6132 pubkey: ln_test_utils::pubkey(42),
6133 node_features: NodeFeatures::empty(),
6134 short_channel_id: 42,
6135 channel_features: ChannelFeatures::empty(),
6137 cltv_expiry_delta: 0,
6140 pubkey: blinded_path.introduction_node_id,
6141 node_features: NodeFeatures::empty(),
6142 short_channel_id: 43,
6143 channel_features: ChannelFeatures::empty(),
6145 cltv_expiry_delta: 0,
6147 blinded_tail: Some(BlindedTail {
6148 hops: blinded_path.blinded_hops,
6149 blinding_point: blinded_path.blinding_point,
6150 excess_final_cltv_expiry_delta: 0,
6151 final_value_msat: 200,
6154 inflight_htlcs.process_path(&path, ln_test_utils::pubkey(44));
6155 assert_eq!(*inflight_htlcs.0.get(&(42, true)).unwrap(), 301);
6156 assert_eq!(*inflight_htlcs.0.get(&(43, false)).unwrap(), 201);
6160 fn blinded_path_cltv_shadow_offset() {
6161 // Make sure we add a shadow offset when sending to blinded paths.
6162 let blinded_path = BlindedPath {
6163 introduction_node_id: ln_test_utils::pubkey(43),
6164 blinding_point: ln_test_utils::pubkey(44),
6166 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() },
6167 BlindedHop { blinded_node_id: ln_test_utils::pubkey(46), encrypted_payload: Vec::new() }
6170 let mut route = Route { paths: vec![Path {
6171 hops: vec![RouteHop {
6172 pubkey: ln_test_utils::pubkey(42),
6173 node_features: NodeFeatures::empty(),
6174 short_channel_id: 42,
6175 channel_features: ChannelFeatures::empty(),
6177 cltv_expiry_delta: 0,
6180 pubkey: blinded_path.introduction_node_id,
6181 node_features: NodeFeatures::empty(),
6182 short_channel_id: 43,
6183 channel_features: ChannelFeatures::empty(),
6185 cltv_expiry_delta: 0,
6188 blinded_tail: Some(BlindedTail {
6189 hops: blinded_path.blinded_hops,
6190 blinding_point: blinded_path.blinding_point,
6191 excess_final_cltv_expiry_delta: 0,
6192 final_value_msat: 200,
6194 }], payment_params: None};
6196 let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
6197 let (_, network_graph, _, _, _) = build_line_graph();
6198 add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
6199 assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
6200 assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
6204 #[cfg(all(any(test, ldk_bench), not(feature = "no-std")))]
6205 pub(crate) mod bench_utils {
6209 use bitcoin::hashes::Hash;
6210 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
6212 use crate::chain::transaction::OutPoint;
6213 use crate::sign::{EntropySource, KeysManager};
6214 use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
6215 use crate::ln::features::InvoiceFeatures;
6216 use crate::routing::gossip::NetworkGraph;
6217 use crate::util::config::UserConfig;
6218 use crate::util::ser::ReadableArgs;
6219 use crate::util::test_utils::TestLogger;
6221 /// Tries to open a network graph file, or panics with a URL to fetch it.
6222 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
6223 let res = File::open("net_graph-2023-01-18.bin") // By default we're run in RL/lightning
6224 .or_else(|_| File::open("lightning/net_graph-2023-01-18.bin")) // We may be run manually in RL/
6225 .or_else(|_| { // Fall back to guessing based on the binary location
6226 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
6227 let mut path = std::env::current_exe().unwrap();
6228 path.pop(); // lightning-...
6230 path.pop(); // debug
6231 path.pop(); // target
6232 path.push("lightning");
6233 path.push("net_graph-2023-01-18.bin");
6236 .or_else(|_| { // Fall back to guessing based on the binary location for a subcrate
6237 // path is likely something like .../rust-lightning/bench/target/debug/deps/bench..
6238 let mut path = std::env::current_exe().unwrap();
6239 path.pop(); // bench...
6241 path.pop(); // debug
6242 path.pop(); // target
6243 path.pop(); // bench
6244 path.push("lightning");
6245 path.push("net_graph-2023-01-18.bin");
6248 .map_err(|_| "Please fetch https://bitcoin.ninja/ldk-net_graph-v0.0.113-2023-01-18.bin and place it at lightning/net_graph-2023-01-18.bin");
6249 #[cfg(require_route_graph_test)]
6250 return Ok(res.unwrap());
6251 #[cfg(not(require_route_graph_test))]
6255 pub(crate) fn read_network_graph(logger: &TestLogger) -> Result<NetworkGraph<&TestLogger>, &'static str> {
6256 get_route_file().map(|mut f| NetworkGraph::read(&mut f, logger).unwrap())
6259 pub(crate) fn payer_pubkey() -> PublicKey {
6260 let secp_ctx = Secp256k1::new();
6261 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
6265 pub(crate) fn first_hop(node_id: PublicKey) -> ChannelDetails {
6267 channel_id: [0; 32],
6268 counterparty: ChannelCounterparty {
6269 features: channelmanager::provided_init_features(&UserConfig::default()),
6271 unspendable_punishment_reserve: 0,
6272 forwarding_info: None,
6273 outbound_htlc_minimum_msat: None,
6274 outbound_htlc_maximum_msat: None,
6276 funding_txo: Some(OutPoint {
6277 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
6280 short_channel_id: Some(1),
6281 inbound_scid_alias: None,
6282 outbound_scid_alias: None,
6283 channel_value_satoshis: 10_000_000_000,
6285 balance_msat: 10_000_000_000,
6286 outbound_capacity_msat: 10_000_000_000,
6287 next_outbound_htlc_minimum_msat: 0,
6288 next_outbound_htlc_limit_msat: 10_000_000_000,
6289 inbound_capacity_msat: 0,
6290 unspendable_punishment_reserve: None,
6291 confirmations_required: None,
6292 confirmations: None,
6293 force_close_spend_delay: None,
6295 is_channel_ready: true,
6298 inbound_htlc_minimum_msat: None,
6299 inbound_htlc_maximum_msat: None,
6301 feerate_sat_per_1000_weight: None,
6305 pub(crate) fn generate_test_routes<S: Score>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
6306 score_params: &S::ScoreParams, features: InvoiceFeatures, mut seed: u64,
6307 starting_amount: u64, route_count: usize,
6308 ) -> Vec<(ChannelDetails, PaymentParameters, u64)> {
6309 let payer = payer_pubkey();
6310 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6311 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6313 let nodes = graph.read_only().nodes().clone();
6314 let mut route_endpoints = Vec::new();
6315 // Fetch 1.5x more routes than we need as after we do some scorer updates we may end up
6316 // with some routes we picked being un-routable.
6317 for _ in 0..route_count * 3 / 2 {
6319 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6320 let src = PublicKey::from_slice(nodes.unordered_keys()
6321 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
6322 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6323 let dst = PublicKey::from_slice(nodes.unordered_keys()
6324 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
6325 let params = PaymentParameters::from_node_id(dst, 42)
6326 .with_bolt11_features(features.clone()).unwrap();
6327 let first_hop = first_hop(src);
6328 let amt = starting_amount + seed % 1_000_000;
6330 get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]),
6331 amt, &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok();
6333 // ...and seed the scorer with success and failure data...
6334 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6335 let mut score_amt = seed % 1_000_000_000;
6337 // Generate fail/success paths for a wider range of potential amounts with
6338 // MPP enabled to give us a chance to apply penalties for more potential
6340 let mpp_features = channelmanager::provided_invoice_features(&UserConfig::default());
6341 let params = PaymentParameters::from_node_id(dst, 42)
6342 .with_bolt11_features(mpp_features).unwrap();
6344 let route_res = get_route(&payer, ¶ms, &graph.read_only(),
6345 Some(&[&first_hop]), score_amt, &TestLogger::new(), &scorer,
6346 score_params, &random_seed_bytes);
6347 if let Ok(route) = route_res {
6348 for path in route.paths {
6349 if seed & 0x80 == 0 {
6350 scorer.payment_path_successful(&path);
6352 let short_channel_id = path.hops[path.hops.len() / 2].short_channel_id;
6353 scorer.payment_path_failed(&path, short_channel_id);
6355 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6359 // If we couldn't find a path with a higer amount, reduce and try again.
6363 route_endpoints.push((first_hop, params, amt));
6369 // Because we've changed channel scores, it's possible we'll take different routes to the
6370 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
6371 // requires a too-high CLTV delta.
6372 route_endpoints.retain(|(first_hop, params, amt)| {
6373 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
6374 &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok()
6376 route_endpoints.truncate(route_count);
6377 assert_eq!(route_endpoints.len(), route_count);
6385 use crate::sign::{EntropySource, KeysManager};
6386 use crate::ln::channelmanager;
6387 use crate::ln::features::InvoiceFeatures;
6388 use crate::routing::gossip::NetworkGraph;
6389 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
6390 use crate::util::config::UserConfig;
6391 use crate::util::logger::{Logger, Record};
6392 use crate::util::test_utils::TestLogger;
6394 use criterion::Criterion;
6396 struct DummyLogger {}
6397 impl Logger for DummyLogger {
6398 fn log(&self, _record: &Record) {}
6401 pub fn generate_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
6402 let logger = TestLogger::new();
6403 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6404 let scorer = FixedPenaltyScorer::with_penalty(0);
6405 generate_routes(bench, &network_graph, scorer, &(), InvoiceFeatures::empty(), 0,
6406 "generate_routes_with_zero_penalty_scorer");
6409 pub fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
6410 let logger = TestLogger::new();
6411 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6412 let scorer = FixedPenaltyScorer::with_penalty(0);
6413 generate_routes(bench, &network_graph, scorer, &(),
6414 channelmanager::provided_invoice_features(&UserConfig::default()), 0,
6415 "generate_mpp_routes_with_zero_penalty_scorer");
6418 pub fn generate_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6419 let logger = TestLogger::new();
6420 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6421 let params = ProbabilisticScoringFeeParameters::default();
6422 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6423 generate_routes(bench, &network_graph, scorer, ¶ms, InvoiceFeatures::empty(), 0,
6424 "generate_routes_with_probabilistic_scorer");
6427 pub fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6428 let logger = TestLogger::new();
6429 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6430 let params = ProbabilisticScoringFeeParameters::default();
6431 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6432 generate_routes(bench, &network_graph, scorer, ¶ms,
6433 channelmanager::provided_invoice_features(&UserConfig::default()), 0,
6434 "generate_mpp_routes_with_probabilistic_scorer");
6437 pub fn generate_large_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6438 let logger = TestLogger::new();
6439 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6440 let params = ProbabilisticScoringFeeParameters::default();
6441 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6442 generate_routes(bench, &network_graph, scorer, ¶ms,
6443 channelmanager::provided_invoice_features(&UserConfig::default()), 100_000_000,
6444 "generate_large_mpp_routes_with_probabilistic_scorer");
6447 fn generate_routes<S: Score>(
6448 bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, mut scorer: S,
6449 score_params: &S::ScoreParams, features: InvoiceFeatures, starting_amount: u64,
6450 bench_name: &'static str,
6452 let payer = bench_utils::payer_pubkey();
6453 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6454 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6456 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
6457 let route_endpoints = bench_utils::generate_test_routes(graph, &mut scorer, score_params, features, 0xdeadbeef, starting_amount, 50);
6459 // ...then benchmark finding paths between the nodes we learned.
6461 bench.bench_function(bench_name, |b| b.iter(|| {
6462 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
6463 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
6464 &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok());