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
624 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
625 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta).with_bolt11_features(InvoiceFeatures::for_keysend()).expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
628 /// Includes the payee's features. Errors if the parameters were initialized with blinded payment
631 /// This is not exported to bindings users since bindings don't support move semantics
632 pub fn with_bolt11_features(self, features: InvoiceFeatures) -> Result<Self, ()> {
634 Payee::Blinded { .. } => Err(()),
635 Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
637 payee: Payee::Clear {
638 route_hints, node_id, features: Some(features), final_cltv_expiry_delta
644 /// Includes hints for routing to the payee. Errors if the parameters were initialized with
645 /// blinded payment paths.
647 /// This is not exported to bindings users since bindings don't support move semantics
648 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
650 Payee::Blinded { .. } => Err(()),
651 Payee::Clear { node_id, features, final_cltv_expiry_delta, .. } =>
653 payee: Payee::Clear {
654 route_hints, node_id, features, final_cltv_expiry_delta,
660 /// Includes a payment expiration in seconds relative to the UNIX epoch.
662 /// This is not exported to bindings users since bindings don't support move semantics
663 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
664 Self { expiry_time: Some(expiry_time), ..self }
667 /// Includes a limit for the total CLTV expiry delta which is considered during routing
669 /// This is not exported to bindings users since bindings don't support move semantics
670 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
671 Self { max_total_cltv_expiry_delta, ..self }
674 /// Includes a limit for the maximum number of payment paths that may be used.
676 /// This is not exported to bindings users since bindings don't support move semantics
677 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
678 Self { max_path_count, ..self }
681 /// Includes a limit for the maximum number of payment paths that may be used.
683 /// This is not exported to bindings users since bindings don't support move semantics
684 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
685 Self { max_channel_saturation_power_of_half, ..self }
689 /// The recipient of a payment, differing based on whether they've hidden their identity with route
691 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
693 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
694 /// will be included in the final [`Route`].
696 /// Aggregated routing info and blinded paths, for routing to the payee without knowing their
698 route_hints: Vec<(BlindedPayInfo, BlindedPath)>,
699 /// Features supported by the payee.
701 /// May be set from the payee's invoice. May be `None` if the invoice does not contain any
703 features: Option<Bolt12InvoiceFeatures>,
705 /// The recipient included these route hints in their BOLT11 invoice.
707 /// The node id of the payee.
709 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
710 route_hints: Vec<RouteHint>,
711 /// Features supported by the payee.
713 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
714 /// does not contain any features.
716 /// [`for_keysend`]: PaymentParameters::for_keysend
717 features: Option<InvoiceFeatures>,
718 /// The minimum CLTV delta at the end of the route. This value must not be zero.
719 final_cltv_expiry_delta: u32,
724 fn node_id(&self) -> Option<PublicKey> {
726 Self::Clear { node_id, .. } => Some(*node_id),
730 fn node_features(&self) -> Option<NodeFeatures> {
732 Self::Clear { features, .. } => features.as_ref().map(|f| f.to_context()),
733 Self::Blinded { features, .. } => features.as_ref().map(|f| f.to_context()),
736 fn supports_basic_mpp(&self) -> bool {
738 Self::Clear { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
739 Self::Blinded { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
742 fn features(&self) -> Option<FeaturesRef> {
744 Self::Clear { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt11(f)),
745 Self::Blinded { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt12(f)),
748 fn final_cltv_expiry_delta(&self) -> Option<u32> {
750 Self::Clear { final_cltv_expiry_delta, .. } => Some(*final_cltv_expiry_delta),
756 enum FeaturesRef<'a> {
757 Bolt11(&'a InvoiceFeatures),
758 Bolt12(&'a Bolt12InvoiceFeatures),
761 Bolt11(InvoiceFeatures),
762 Bolt12(Bolt12InvoiceFeatures),
766 fn bolt12(self) -> Option<Bolt12InvoiceFeatures> {
768 Self::Bolt12(f) => Some(f),
772 fn bolt11(self) -> Option<InvoiceFeatures> {
774 Self::Bolt11(f) => Some(f),
780 impl<'a> Writeable for FeaturesRef<'a> {
781 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
783 Self::Bolt11(f) => Ok(f.write(w)?),
784 Self::Bolt12(f) => Ok(f.write(w)?),
789 impl ReadableArgs<bool> for Features {
790 fn read<R: io::Read>(reader: &mut R, bolt11: bool) -> Result<Self, DecodeError> {
791 if bolt11 { return Ok(Self::Bolt11(Readable::read(reader)?)) }
792 Ok(Self::Bolt12(Readable::read(reader)?))
796 /// A list of hops along a payment path terminating with a channel to the recipient.
797 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
798 pub struct RouteHint(pub Vec<RouteHintHop>);
800 impl Writeable for RouteHint {
801 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
802 (self.0.len() as u64).write(writer)?;
803 for hop in self.0.iter() {
810 impl Readable for RouteHint {
811 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
812 let hop_count: u64 = Readable::read(reader)?;
813 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
814 for _ in 0..hop_count {
815 hops.push(Readable::read(reader)?);
821 /// A channel descriptor for a hop along a payment path.
822 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
823 pub struct RouteHintHop {
824 /// The node_id of the non-target end of the route
825 pub src_node_id: PublicKey,
826 /// The short_channel_id of this channel
827 pub short_channel_id: u64,
828 /// The fees which must be paid to use this channel
829 pub fees: RoutingFees,
830 /// The difference in CLTV values between this node and the next node.
831 pub cltv_expiry_delta: u16,
832 /// The minimum value, in msat, which must be relayed to the next hop.
833 pub htlc_minimum_msat: Option<u64>,
834 /// The maximum value in msat available for routing with a single HTLC.
835 pub htlc_maximum_msat: Option<u64>,
838 impl_writeable_tlv_based!(RouteHintHop, {
839 (0, src_node_id, required),
840 (1, htlc_minimum_msat, option),
841 (2, short_channel_id, required),
842 (3, htlc_maximum_msat, option),
844 (6, cltv_expiry_delta, required),
847 #[derive(Eq, PartialEq)]
848 struct RouteGraphNode {
850 lowest_fee_to_node: u64,
851 total_cltv_delta: u32,
852 // The maximum value a yet-to-be-constructed payment path might flow through this node.
853 // This value is upper-bounded by us by:
854 // - how much is needed for a path being constructed
855 // - how much value can channels following this node (up to the destination) can contribute,
856 // considering their capacity and fees
857 value_contribution_msat: u64,
858 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
859 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
860 path_htlc_minimum_msat: u64,
861 /// All penalties incurred from this hop on the way to the destination, as calculated using
863 path_penalty_msat: u64,
864 /// The number of hops walked up to this node.
865 path_length_to_node: u8,
868 impl cmp::Ord for RouteGraphNode {
869 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
870 let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat)
871 .saturating_add(other.path_penalty_msat);
872 let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat)
873 .saturating_add(self.path_penalty_msat);
874 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
878 impl cmp::PartialOrd for RouteGraphNode {
879 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
880 Some(self.cmp(other))
884 /// A wrapper around the various hop representations.
886 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
887 #[derive(Clone, Debug)]
888 enum CandidateRouteHop<'a> {
889 /// A hop from the payer, where the outbound liquidity is known.
891 details: &'a ChannelDetails,
893 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
895 info: DirectedChannelInfo<'a>,
896 short_channel_id: u64,
898 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
900 hint: &'a RouteHintHop,
904 impl<'a> CandidateRouteHop<'a> {
905 fn short_channel_id(&self) -> u64 {
907 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
908 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
909 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
913 // NOTE: This may alloc memory so avoid calling it in a hot code path.
914 fn features(&self) -> ChannelFeatures {
916 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
917 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
918 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
922 fn cltv_expiry_delta(&self) -> u32 {
924 CandidateRouteHop::FirstHop { .. } => 0,
925 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
926 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
930 fn htlc_minimum_msat(&self) -> u64 {
932 CandidateRouteHop::FirstHop { .. } => 0,
933 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
934 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
938 fn fees(&self) -> RoutingFees {
940 CandidateRouteHop::FirstHop { .. } => RoutingFees {
941 base_msat: 0, proportional_millionths: 0,
943 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
944 CandidateRouteHop::PrivateHop { hint } => hint.fees,
948 fn effective_capacity(&self) -> EffectiveCapacity {
950 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
951 liquidity_msat: details.next_outbound_htlc_limit_msat,
953 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
954 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
955 EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
956 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
957 EffectiveCapacity::Infinite,
963 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
964 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
966 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
967 EffectiveCapacity::Infinite => u64::max_value(),
968 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
969 EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
970 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
971 // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
972 // expected to have been generated from up-to-date capacity information.
973 EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
974 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
975 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
979 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
980 -> bool where I1::Item: PartialEq<I2::Item> {
982 let a = iter_a.next();
983 let b = iter_b.next();
984 if a.is_none() && b.is_none() { return true; }
985 if a.is_none() || b.is_none() { return false; }
986 if a.unwrap().ne(&b.unwrap()) { return false; }
990 /// It's useful to keep track of the hops associated with the fees required to use them,
991 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
992 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
993 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
995 struct PathBuildingHop<'a> {
996 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
997 // is a larger refactor and will require careful performance analysis.
999 candidate: CandidateRouteHop<'a>,
1002 /// All the fees paid *after* this channel on the way to the destination
1003 next_hops_fee_msat: u64,
1004 /// Fee paid for the use of the current channel (see candidate.fees()).
1005 /// The value will be actually deducted from the counterparty balance on the previous link.
1006 hop_use_fee_msat: u64,
1007 /// Used to compare channels when choosing the for routing.
1008 /// Includes paying for the use of a hop and the following hops, as well as
1009 /// an estimated cost of reaching this hop.
1010 /// Might get stale when fees are recomputed. Primarily for internal use.
1011 total_fee_msat: u64,
1012 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
1013 /// walk and may be invalid thereafter.
1014 path_htlc_minimum_msat: u64,
1015 /// All penalties incurred from this channel on the way to the destination, as calculated using
1016 /// channel scoring.
1017 path_penalty_msat: u64,
1018 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
1019 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
1020 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
1021 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
1022 /// avoid processing them again.
1023 was_processed: bool,
1024 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1025 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
1026 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
1027 // value_contribution_msat, which requires tracking it here. See comments below where it is
1028 // used for more info.
1029 value_contribution_msat: u64,
1032 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
1033 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1034 let mut debug_struct = f.debug_struct("PathBuildingHop");
1036 .field("node_id", &self.node_id)
1037 .field("short_channel_id", &self.candidate.short_channel_id())
1038 .field("total_fee_msat", &self.total_fee_msat)
1039 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
1040 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
1041 .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)))
1042 .field("path_penalty_msat", &self.path_penalty_msat)
1043 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
1044 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
1045 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1046 let debug_struct = debug_struct
1047 .field("value_contribution_msat", &self.value_contribution_msat);
1048 debug_struct.finish()
1052 // Instantiated with a list of hops with correct data in them collected during path finding,
1053 // an instance of this struct should be further modified only via given methods.
1055 struct PaymentPath<'a> {
1056 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
1059 impl<'a> PaymentPath<'a> {
1060 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
1061 fn get_value_msat(&self) -> u64 {
1062 self.hops.last().unwrap().0.fee_msat
1065 fn get_path_penalty_msat(&self) -> u64 {
1066 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
1069 fn get_total_fee_paid_msat(&self) -> u64 {
1070 if self.hops.len() < 1 {
1074 // Can't use next_hops_fee_msat because it gets outdated.
1075 for (i, (hop, _)) in self.hops.iter().enumerate() {
1076 if i != self.hops.len() - 1 {
1077 result += hop.fee_msat;
1083 fn get_cost_msat(&self) -> u64 {
1084 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
1087 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
1088 // to change fees may result in an inconsistency.
1090 // Sometimes we call this function right after constructing a path which is inconsistent in
1091 // that it the value being transferred has decreased while we were doing path finding, leading
1092 // to the fees being paid not lining up with the actual limits.
1094 // Note that this function is not aware of the available_liquidity limit, and thus does not
1095 // support increasing the value being transferred beyond what was selected during the initial
1097 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
1098 let mut total_fee_paid_msat = 0 as u64;
1099 for i in (0..self.hops.len()).rev() {
1100 let last_hop = i == self.hops.len() - 1;
1102 // For non-last-hop, this value will represent the fees paid on the current hop. It
1103 // will consist of the fees for the use of the next hop, and extra fees to match
1104 // htlc_minimum_msat of the current channel. Last hop is handled separately.
1105 let mut cur_hop_fees_msat = 0;
1107 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
1110 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
1111 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
1112 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
1113 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
1114 // set it too high just to maliciously take more fees by exploiting this
1115 // match htlc_minimum_msat logic.
1116 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
1117 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
1118 // Note that there is a risk that *previous hops* (those closer to us, as we go
1119 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
1121 // This might make us end up with a broken route, although this should be super-rare
1122 // in practice, both because of how healthy channels look like, and how we pick
1123 // channels in add_entry.
1124 // Also, this can't be exploited more heavily than *announce a free path and fail
1126 cur_hop_transferred_amount_msat += extra_fees_msat;
1127 total_fee_paid_msat += extra_fees_msat;
1128 cur_hop_fees_msat += extra_fees_msat;
1132 // Final hop is a special case: it usually has just value_msat (by design), but also
1133 // it still could overpay for the htlc_minimum_msat.
1134 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
1136 // Propagate updated fees for the use of the channels to one hop back, where they
1137 // will be actually paid (fee_msat). The last hop is handled above separately.
1138 cur_hop.fee_msat = cur_hop_fees_msat;
1141 // Fee for the use of the current hop which will be deducted on the previous hop.
1142 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
1143 // this channel is free for us.
1145 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
1146 cur_hop.hop_use_fee_msat = new_fee;
1147 total_fee_paid_msat += new_fee;
1149 // It should not be possible because this function is called only to reduce the
1150 // value. In that case, compute_fee was already called with the same fees for
1151 // larger amount and there was no overflow.
1160 /// Calculate the fees required to route the given amount over a channel with the given fees.
1161 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
1162 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1163 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
1167 /// Calculate the fees required to route the given amount over a channel with the given fees,
1168 /// saturating to [`u64::max_value`].
1169 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
1170 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1171 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
1172 .saturating_add(channel_fees.base_msat as u64)
1175 /// The default `features` we assume for a node in a route, when no `features` are known about that
1178 /// Default features are:
1179 /// * variable_length_onion_optional
1180 fn default_node_features() -> NodeFeatures {
1181 let mut features = NodeFeatures::empty();
1182 features.set_variable_length_onion_optional();
1186 struct LoggedPayeePubkey(Option<PublicKey>);
1187 impl fmt::Display for LoggedPayeePubkey {
1188 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1191 "payee node id ".fmt(f)?;
1195 "blinded payee".fmt(f)
1201 /// Finds a route from us (payer) to the given target node (payee).
1203 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
1204 /// Without this, MPP will only be used if the payee's features are available in the network graph.
1206 /// Private routing paths between a public node and the target may be included in `params.payee`.
1208 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
1209 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
1210 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
1212 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1213 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1214 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1218 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
1219 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
1224 /// Panics if first_hops contains channels without short_channel_ids;
1225 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1227 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1228 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1229 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1230 pub fn find_route<L: Deref, GL: Deref, S: Score>(
1231 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1232 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1233 scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
1234 ) -> Result<Route, LightningError>
1235 where L::Target: Logger, GL::Target: Logger {
1236 let graph_lock = network_graph.read_only();
1237 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
1238 route_params.final_value_msat, logger, scorer, score_params,
1239 random_seed_bytes)?;
1240 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1244 pub(crate) fn get_route<L: Deref, S: Score>(
1245 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
1246 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, logger: L, scorer: &S, score_params: &S::ScoreParams,
1247 _random_seed_bytes: &[u8; 32]
1248 ) -> Result<Route, LightningError>
1249 where L::Target: Logger {
1250 // If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
1251 // unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
1252 // so use a dummy id for this in the blinded case.
1253 let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
1254 const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [42u8; 33];
1255 let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
1256 let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
1257 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1259 if payee_node_id_opt.map_or(false, |payee| payee == our_node_id) {
1260 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1263 if final_value_msat > MAX_VALUE_MSAT {
1264 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1267 if final_value_msat == 0 {
1268 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1271 match &payment_params.payee {
1272 Payee::Clear { route_hints, node_id, .. } => {
1273 for route in route_hints.iter() {
1274 for hop in &route.0 {
1275 if hop.src_node_id == *node_id {
1276 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1281 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1284 let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
1285 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1286 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});
1289 // The general routing idea is the following:
1290 // 1. Fill first/last hops communicated by the caller.
1291 // 2. Attempt to construct a path from payer to payee for transferring
1292 // any ~sufficient (described later) value.
1293 // If succeed, remember which channels were used and how much liquidity they have available,
1294 // so that future paths don't rely on the same liquidity.
1295 // 3. Proceed to the next step if:
1296 // - we hit the recommended target value;
1297 // - OR if we could not construct a new path. Any next attempt will fail too.
1298 // Otherwise, repeat step 2.
1299 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1300 // (not recommended value).
1301 // 5. If yes, proceed. If not, fail routing.
1302 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1303 // transferred up to the transfer target value.
1304 // 7. Reduce the value of the last path until we are sending only the target value.
1305 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1306 // them so that we're not sending two HTLCs along the same path.
1308 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1309 // distance from the payee
1311 // We are not a faithful Dijkstra's implementation because we can change values which impact
1312 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1313 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1314 // the value we are currently attempting to send over a path, we simply reduce the value being
1315 // sent along the path for any hops after that channel. This may imply that later fees (which
1316 // we've already tabulated) are lower because a smaller value is passing through the channels
1317 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1318 // channels which were selected earlier (and which may still be used for other paths without a
1319 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1322 // One potentially problematic case for this algorithm would be if there are many
1323 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1324 // graph walking), we may never find a path which is not liquidity-limited and has lower
1325 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1326 // Because we only consider paths with at least 5% of the total value being sent, the damage
1327 // from such a case should be limited, however this could be further reduced in the future by
1328 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1329 // limits for the purposes of fee calculation.
1331 // Alternatively, we could store more detailed path information in the heap (targets, below)
1332 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1333 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1334 // and practically (as we would need to store dynamically-allocated path information in heap
1335 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
1336 // results of such an algorithm would likely be biased towards lower-value paths.
1338 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
1339 // outside of our current search value, running a path search more times to gather candidate
1340 // paths at different values. While this may be acceptable, further path searches may increase
1341 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
1342 // graph for candidate paths, calculating the maximum value which can realistically be sent at
1343 // the same time, remaining generic across different payment values.
1345 let network_channels = network_graph.channels();
1346 let network_nodes = network_graph.nodes();
1348 if payment_params.max_path_count == 0 {
1349 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
1352 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
1353 // it. If the payee supports it they're supposed to include it in the invoice, so that should
1355 let allow_mpp = if payment_params.max_path_count == 1 {
1357 } else if payment_params.payee.supports_basic_mpp() {
1359 } else if let Some(payee) = payee_node_id_opt {
1360 network_nodes.get(&payee).map_or(false, |node| node.announcement_info.as_ref().map_or(false,
1361 |info| info.features.supports_basic_mpp()))
1364 log_trace!(logger, "Searching for a route from payer {} to {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
1365 LoggedPayeePubkey(payment_params.payee.node_id()), if allow_mpp { "with" } else { "without" },
1366 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
1369 // Prepare the data we'll use for payee-to-payer search by
1370 // inserting first hops suggested by the caller as targets.
1371 // Our search will then attempt to reach them while traversing from the payee node.
1372 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
1373 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
1374 if let Some(hops) = first_hops {
1376 if chan.get_outbound_payment_scid().is_none() {
1377 panic!("first_hops should be filled in with usable channels, not pending ones");
1379 if chan.counterparty.node_id == *our_node_pubkey {
1380 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
1383 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
1384 .or_insert(Vec::new())
1387 if first_hop_targets.is_empty() {
1388 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
1392 // The main heap containing all candidate next-hops sorted by their score (max(fee,
1393 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
1394 // adding duplicate entries when we find a better path to a given node.
1395 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
1397 // Map from node_id to information about the best current path to that node, including feerate
1399 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
1401 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
1402 // indicating that we may wish to try again with a higher value, potentially paying to meet an
1403 // htlc_minimum with extra fees while still finding a cheaper path.
1404 let mut hit_minimum_limit;
1406 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
1407 // We start with a path_value of the exact amount we want, and if that generates a route we may
1408 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
1409 // amount we want in total across paths, selecting the best subset at the end.
1410 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
1411 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
1412 let mut path_value_msat = final_value_msat;
1414 // Routing Fragmentation Mitigation heuristic:
1416 // Routing fragmentation across many payment paths increases the overall routing
1417 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
1418 // Taking too many smaller paths also increases the chance of payment failure.
1419 // Thus to avoid this effect, we require from our collected links to provide
1420 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
1421 // This requirement is currently set to be 1/max_path_count of the payment
1422 // value to ensure we only ever return routes that do not violate this limit.
1423 let minimal_value_contribution_msat: u64 = if allow_mpp {
1424 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
1429 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
1430 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
1431 // drop the requirement by setting this to 0.
1432 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
1434 // Keep track of how much liquidity has been used in selected channels. Used to determine
1435 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
1436 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
1437 // liquidity used in one direction will not offset any used in the opposite direction.
1438 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
1439 HashMap::with_capacity(network_nodes.len());
1441 // Keeping track of how much value we already collected across other paths. Helps to decide
1442 // when we want to stop looking for new paths.
1443 let mut already_collected_value_msat = 0;
1445 for (_, channels) in first_hop_targets.iter_mut() {
1446 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1447 // most like to use.
1449 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1450 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1453 // Second, because simply always sorting in descending order would always use our largest
1454 // available outbound capacity, needlessly fragmenting our available channel capacities,
1455 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1456 // which have enough, but not too much, capacity for the payment.
1457 channels.sort_unstable_by(|chan_a, chan_b| {
1458 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
1459 // Sort in descending order
1460 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
1462 // Sort in ascending order
1463 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
1468 log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
1469 LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
1471 macro_rules! add_entry {
1472 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
1473 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
1474 // since that value has to be transferred over this channel.
1475 // Returns whether this channel caused an update to `targets`.
1476 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
1477 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
1478 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
1479 // We "return" whether we updated the path at the end, and how much we can route via
1480 // this channel, via this:
1481 let mut did_add_update_path_to_src_node = None;
1482 // Channels to self should not be used. This is more of belt-and-suspenders, because in
1483 // practice these cases should be caught earlier:
1484 // - for regular channels at channel announcement (TODO)
1485 // - for first and last hops early in get_route
1486 if $src_node_id != $dest_node_id {
1487 let short_channel_id = $candidate.short_channel_id();
1488 let effective_capacity = $candidate.effective_capacity();
1489 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
1491 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
1492 // It may be misleading because we might later choose to reduce the value transferred
1493 // over these channels, and the channel which was insufficient might become sufficient.
1494 // Worst case: we drop a good channel here because it can't cover the high following
1495 // fees caused by one expensive channel, but then this channel could have been used
1496 // if the amount being transferred over this path is lower.
1497 // We do this for now, but this is a subject for removal.
1498 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
1499 let used_liquidity_msat = used_channel_liquidities
1500 .get(&(short_channel_id, $src_node_id < $dest_node_id))
1501 .map_or(0, |used_liquidity_msat| {
1502 available_value_contribution_msat = available_value_contribution_msat
1503 .saturating_sub(*used_liquidity_msat);
1504 *used_liquidity_msat
1507 // Verify the liquidity offered by this channel complies to the minimal contribution.
1508 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
1509 // Do not consider candidate hops that would exceed the maximum path length.
1510 let path_length_to_node = $next_hops_path_length + 1;
1511 let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
1513 // Do not consider candidates that exceed the maximum total cltv expiry limit.
1514 // In order to already account for some of the privacy enhancing random CLTV
1515 // expiry delta offset we add on top later, we subtract a rough estimate
1516 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
1517 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
1518 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
1519 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
1520 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
1521 .saturating_add($candidate.cltv_expiry_delta());
1522 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
1524 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
1525 // Includes paying fees for the use of the following channels.
1526 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
1527 Some(result) => result,
1528 // Can't overflow due to how the values were computed right above.
1529 None => unreachable!(),
1531 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1532 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
1533 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
1535 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1536 let may_overpay_to_meet_path_minimum_msat =
1537 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
1538 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
1539 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
1540 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
1542 let payment_failed_on_this_channel =
1543 payment_params.previously_failed_channels.contains(&short_channel_id);
1545 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
1546 // bother considering this channel. If retrying with recommended_value_msat may
1547 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
1548 // around again with a higher amount.
1549 if !contributes_sufficient_value || exceeds_max_path_length ||
1550 exceeds_cltv_delta_limit || payment_failed_on_this_channel {
1551 // Path isn't useful, ignore it and move on.
1552 } else if may_overpay_to_meet_path_minimum_msat {
1553 hit_minimum_limit = true;
1554 } else if over_path_minimum_msat {
1555 // Note that low contribution here (limited by available_liquidity_msat)
1556 // might violate htlc_minimum_msat on the hops which are next along the
1557 // payment path (upstream to the payee). To avoid that, we recompute
1558 // path fees knowing the final path contribution after constructing it.
1559 let path_htlc_minimum_msat = cmp::max(
1560 compute_fees_saturating($next_hops_path_htlc_minimum_msat, $candidate.fees())
1561 .saturating_add($next_hops_path_htlc_minimum_msat),
1562 $candidate.htlc_minimum_msat());
1563 let hm_entry = dist.entry($src_node_id);
1564 let old_entry = hm_entry.or_insert_with(|| {
1565 // If there was previously no known way to access the source node
1566 // (recall it goes payee-to-payer) of short_channel_id, first add a
1567 // semi-dummy record just to compute the fees to reach the source node.
1568 // This will affect our decision on selecting short_channel_id
1569 // as a way to reach the $dest_node_id.
1571 node_id: $dest_node_id.clone(),
1572 candidate: $candidate.clone(),
1574 next_hops_fee_msat: u64::max_value(),
1575 hop_use_fee_msat: u64::max_value(),
1576 total_fee_msat: u64::max_value(),
1577 path_htlc_minimum_msat,
1578 path_penalty_msat: u64::max_value(),
1579 was_processed: false,
1580 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1581 value_contribution_msat,
1585 #[allow(unused_mut)] // We only use the mut in cfg(test)
1586 let mut should_process = !old_entry.was_processed;
1587 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1589 // In test/fuzzing builds, we do extra checks to make sure the skipping
1590 // of already-seen nodes only happens in cases we expect (see below).
1591 if !should_process { should_process = true; }
1595 let mut hop_use_fee_msat = 0;
1596 let mut total_fee_msat: u64 = $next_hops_fee_msat;
1598 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1599 // will have the same effective-fee
1600 if $src_node_id != our_node_id {
1601 // Note that `u64::max_value` means we'll always fail the
1602 // `old_entry.total_fee_msat > total_fee_msat` check below
1603 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
1604 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
1607 let channel_usage = ChannelUsage {
1608 amount_msat: amount_to_transfer_over_msat,
1609 inflight_htlc_msat: used_liquidity_msat,
1612 let channel_penalty_msat = scorer.channel_penalty_msat(
1613 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage, score_params
1615 let path_penalty_msat = $next_hops_path_penalty_msat
1616 .saturating_add(channel_penalty_msat);
1617 let new_graph_node = RouteGraphNode {
1618 node_id: $src_node_id,
1619 lowest_fee_to_node: total_fee_msat,
1620 total_cltv_delta: hop_total_cltv_delta,
1621 value_contribution_msat,
1622 path_htlc_minimum_msat,
1624 path_length_to_node,
1627 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1628 // if this way is cheaper than the already known
1629 // (considering the cost to "reach" this channel from the route destination,
1630 // the cost of using this channel,
1631 // and the cost of routing to the source node of this channel).
1632 // Also, consider that htlc_minimum_msat_difference, because we might end up
1633 // paying it. Consider the following exploit:
1634 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1635 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1636 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1637 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1639 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1640 // but it may require additional tracking - we don't want to double-count
1641 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1642 // can't use something that may decrease on future hops.
1643 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1644 .saturating_add(old_entry.path_penalty_msat);
1645 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1646 .saturating_add(path_penalty_msat);
1648 if !old_entry.was_processed && new_cost < old_cost {
1649 targets.push(new_graph_node);
1650 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1651 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1652 old_entry.total_fee_msat = total_fee_msat;
1653 old_entry.node_id = $dest_node_id.clone();
1654 old_entry.candidate = $candidate.clone();
1655 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1656 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1657 old_entry.path_penalty_msat = path_penalty_msat;
1658 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1660 old_entry.value_contribution_msat = value_contribution_msat;
1662 did_add_update_path_to_src_node = Some(value_contribution_msat);
1663 } else if old_entry.was_processed && new_cost < old_cost {
1664 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1666 // If we're skipping processing a node which was previously
1667 // processed even though we found another path to it with a
1668 // cheaper fee, check that it was because the second path we
1669 // found (which we are processing now) has a lower value
1670 // contribution due to an HTLC minimum limit.
1672 // e.g. take a graph with two paths from node 1 to node 2, one
1673 // through channel A, and one through channel B. Channel A and
1674 // B are both in the to-process heap, with their scores set by
1675 // a higher htlc_minimum than fee.
1676 // Channel A is processed first, and the channels onwards from
1677 // node 1 are added to the to-process heap. Thereafter, we pop
1678 // Channel B off of the heap, note that it has a much more
1679 // restrictive htlc_maximum_msat, and recalculate the fees for
1680 // all of node 1's channels using the new, reduced, amount.
1682 // This would be bogus - we'd be selecting a higher-fee path
1683 // with a lower htlc_maximum_msat instead of the one we'd
1684 // already decided to use.
1685 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1687 value_contribution_msat + path_penalty_msat <
1688 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1696 did_add_update_path_to_src_node
1700 let default_node_features = default_node_features();
1702 // Find ways (channels with destination) to reach a given node and store them
1703 // in the corresponding data structures (routing graph etc).
1704 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1705 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1706 // This data can later be helpful to optimize routing (pay lower fees).
1707 macro_rules! add_entries_to_cheapest_to_target_node {
1708 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1709 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1710 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1711 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1712 let was_processed = elem.was_processed;
1713 elem.was_processed = true;
1716 // Entries are added to dist in add_entry!() when there is a channel from a node.
1717 // Because there are no channels from payee, it will not have a dist entry at this point.
1718 // If we're processing any other node, it is always be the result of a channel from it.
1719 debug_assert_eq!($node_id, maybe_dummy_payee_node_id);
1724 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1725 for details in first_channels {
1726 let candidate = CandidateRouteHop::FirstHop { details };
1727 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1728 $next_hops_value_contribution,
1729 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1730 $next_hops_cltv_delta, $next_hops_path_length);
1734 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1737 &default_node_features
1740 if !features.requires_unknown_bits() {
1741 for chan_id in $node.channels.iter() {
1742 let chan = network_channels.get(chan_id).unwrap();
1743 if !chan.features.requires_unknown_bits() {
1744 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
1745 if first_hops.is_none() || *source != our_node_id {
1746 if directed_channel.direction().enabled {
1747 let candidate = CandidateRouteHop::PublicHop {
1748 info: directed_channel,
1749 short_channel_id: *chan_id,
1751 add_entry!(candidate, *source, $node_id,
1752 $fee_to_target_msat,
1753 $next_hops_value_contribution,
1754 $next_hops_path_htlc_minimum_msat,
1755 $next_hops_path_penalty_msat,
1756 $next_hops_cltv_delta, $next_hops_path_length);
1767 let mut payment_paths = Vec::<PaymentPath>::new();
1769 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1770 'paths_collection: loop {
1771 // For every new path, start from scratch, except for used_channel_liquidities, which
1772 // helps to avoid reusing previously selected paths in future iterations.
1775 hit_minimum_limit = false;
1777 // If first hop is a private channel and the only way to reach the payee, this is the only
1778 // place where it could be added.
1779 payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| {
1780 for details in first_channels {
1781 let candidate = CandidateRouteHop::FirstHop { details };
1782 let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
1783 0, 0u64, 0, 0).is_some();
1784 log_trace!(logger, "{} direct route to payee via SCID {}",
1785 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1789 // Add the payee as a target, so that the payee-to-payer
1790 // search algorithm knows what to start with.
1791 payee_node_id_opt.map(|payee| match network_nodes.get(&payee) {
1792 // The payee is not in our network graph, so nothing to add here.
1793 // There is still a chance of reaching them via last_hops though,
1794 // so don't yet fail the payment here.
1795 // If not, targets.pop() will not even let us enter the loop in step 2.
1798 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0, 0u64, 0, 0);
1803 // If a caller provided us with last hops, add them to routing targets. Since this happens
1804 // earlier than general path finding, they will be somewhat prioritized, although currently
1805 // it matters only if the fees are exactly the same.
1806 let route_hints = match &payment_params.payee {
1807 Payee::Clear { route_hints, .. } => route_hints,
1808 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1810 for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
1811 let first_hop_in_route = &(route.0)[0];
1812 let have_hop_src_in_graph =
1813 // Only add the hops in this route to our candidate set if either
1814 // we have a direct channel to the first hop or the first hop is
1815 // in the regular network graph.
1816 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1817 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1818 if have_hop_src_in_graph {
1819 // We start building the path from reverse, i.e., from payee
1820 // to the first RouteHintHop in the path.
1821 let hop_iter = route.0.iter().rev();
1822 let prev_hop_iter = core::iter::once(&maybe_dummy_payee_pk).chain(
1823 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1824 let mut hop_used = true;
1825 let mut aggregate_next_hops_fee_msat: u64 = 0;
1826 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1827 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1828 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1829 let mut aggregate_next_hops_path_length: u8 = 0;
1830 let mut aggregate_path_contribution_msat = path_value_msat;
1832 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1833 let source = NodeId::from_pubkey(&hop.src_node_id);
1834 let target = NodeId::from_pubkey(&prev_hop_id);
1835 let candidate = network_channels
1836 .get(&hop.short_channel_id)
1837 .and_then(|channel| channel.as_directed_to(&target))
1838 .map(|(info, _)| CandidateRouteHop::PublicHop {
1840 short_channel_id: hop.short_channel_id,
1842 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1844 if let Some(hop_used_msat) = add_entry!(candidate, source, target,
1845 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
1846 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
1847 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
1849 aggregate_path_contribution_msat = hop_used_msat;
1851 // If this hop was not used then there is no use checking the preceding
1852 // hops in the RouteHint. We can break by just searching for a direct
1853 // channel between last checked hop and first_hop_targets.
1857 let used_liquidity_msat = used_channel_liquidities
1858 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1859 let channel_usage = ChannelUsage {
1860 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1861 inflight_htlc_msat: used_liquidity_msat,
1862 effective_capacity: candidate.effective_capacity(),
1864 let channel_penalty_msat = scorer.channel_penalty_msat(
1865 hop.short_channel_id, &source, &target, channel_usage, score_params
1867 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1868 .saturating_add(channel_penalty_msat);
1870 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1871 .saturating_add(hop.cltv_expiry_delta as u32);
1873 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1876 // Searching for a direct channel between last checked hop and first_hop_targets
1877 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1878 for details in first_channels {
1879 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
1880 add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1881 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
1882 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
1883 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
1891 // In the next values of the iterator, the aggregate fees already reflects
1892 // the sum of value sent from payer (final_value_msat) and routing fees
1893 // for the last node in the RouteHint. We need to just add the fees to
1894 // route through the current node so that the preceding node (next iteration)
1896 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1897 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1898 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1900 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1901 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1902 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1903 .checked_add(hop_htlc_minimum_msat_inc);
1904 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1906 if idx == route.0.len() - 1 {
1907 // The last hop in this iterator is the first hop in
1908 // overall RouteHint.
1909 // If this hop connects to a node with which we have a direct channel,
1910 // ignore the network graph and, if the last hop was added, add our
1911 // direct channel to the candidate set.
1913 // Note that we *must* check if the last hop was added as `add_entry`
1914 // always assumes that the third argument is a node to which we have a
1916 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1917 for details in first_channels {
1918 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
1919 add_entry!(first_hop_candidate, our_node_id,
1920 NodeId::from_pubkey(&hop.src_node_id),
1921 aggregate_next_hops_fee_msat,
1922 aggregate_path_contribution_msat,
1923 aggregate_next_hops_path_htlc_minimum_msat,
1924 aggregate_next_hops_path_penalty_msat,
1925 aggregate_next_hops_cltv_delta,
1926 aggregate_next_hops_path_length);
1934 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1936 // At this point, targets are filled with the data from first and
1937 // last hops communicated by the caller, and the payment receiver.
1938 let mut found_new_path = false;
1941 // If this loop terminates due the exhaustion of targets, two situations are possible:
1942 // - not enough outgoing liquidity:
1943 // 0 < already_collected_value_msat < final_value_msat
1944 // - enough outgoing liquidity:
1945 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1946 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1947 // paths_collection will be stopped because found_new_path==false.
1948 // This is not necessarily a routing failure.
1949 '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() {
1951 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1952 // traversing the graph and arrange the path out of what we found.
1953 if node_id == our_node_id {
1954 let mut new_entry = dist.remove(&our_node_id).unwrap();
1955 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1958 let mut features_set = false;
1959 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1960 for details in first_channels {
1961 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1962 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1963 features_set = true;
1969 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1970 if let Some(node_info) = node.announcement_info.as_ref() {
1971 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1973 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1976 // We can fill in features for everything except hops which were
1977 // provided via the invoice we're paying. We could guess based on the
1978 // recipient's features but for now we simply avoid guessing at all.
1982 // Means we succesfully traversed from the payer to the payee, now
1983 // save this path for the payment route. Also, update the liquidity
1984 // remaining on the used hops, so that we take them into account
1985 // while looking for more paths.
1986 if ordered_hops.last().unwrap().0.node_id == maybe_dummy_payee_node_id {
1990 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1991 Some(payment_hop) => payment_hop,
1992 // We can't arrive at None because, if we ever add an entry to targets,
1993 // we also fill in the entry in dist (see add_entry!).
1994 None => unreachable!(),
1996 // We "propagate" the fees one hop backward (topologically) here,
1997 // so that fees paid for a HTLC forwarding on the current channel are
1998 // associated with the previous channel (where they will be subtracted).
1999 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
2000 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
2002 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
2003 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
2005 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
2006 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
2008 let mut payment_path = PaymentPath {hops: ordered_hops};
2010 // We could have possibly constructed a slightly inconsistent path: since we reduce
2011 // value being transferred along the way, we could have violated htlc_minimum_msat
2012 // on some channels we already passed (assuming dest->source direction). Here, we
2013 // recompute the fees again, so that if that's the case, we match the currently
2014 // underpaid htlc_minimum_msat with fees.
2015 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
2016 value_contribution_msat = cmp::min(value_contribution_msat, final_value_msat);
2017 payment_path.update_value_and_recompute_fees(value_contribution_msat);
2019 // Since a path allows to transfer as much value as
2020 // the smallest channel it has ("bottleneck"), we should recompute
2021 // the fees so sender HTLC don't overpay fees when traversing
2022 // larger channels than the bottleneck. This may happen because
2023 // when we were selecting those channels we were not aware how much value
2024 // this path will transfer, and the relative fee for them
2025 // might have been computed considering a larger value.
2026 // Remember that we used these channels so that we don't rely
2027 // on the same liquidity in future paths.
2028 let mut prevented_redundant_path_selection = false;
2029 let prev_hop_iter = core::iter::once(&our_node_id)
2030 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
2031 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
2032 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
2033 let used_liquidity_msat = used_channel_liquidities
2034 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
2035 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
2036 .or_insert(spent_on_hop_msat);
2037 let hop_capacity = hop.candidate.effective_capacity();
2038 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
2039 if *used_liquidity_msat == hop_max_msat {
2040 // If this path used all of this channel's available liquidity, we know
2041 // this path will not be selected again in the next loop iteration.
2042 prevented_redundant_path_selection = true;
2044 debug_assert!(*used_liquidity_msat <= hop_max_msat);
2046 if !prevented_redundant_path_selection {
2047 // If we weren't capped by hitting a liquidity limit on a channel in the path,
2048 // we'll probably end up picking the same path again on the next iteration.
2049 // Decrease the available liquidity of a hop in the middle of the path.
2050 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
2051 let exhausted = u64::max_value();
2052 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
2053 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
2054 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
2057 // Track the total amount all our collected paths allow to send so that we know
2058 // when to stop looking for more paths
2059 already_collected_value_msat += value_contribution_msat;
2061 payment_paths.push(payment_path);
2062 found_new_path = true;
2063 break 'path_construction;
2066 // If we found a path back to the payee, we shouldn't try to process it again. This is
2067 // the equivalent of the `elem.was_processed` check in
2068 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
2069 if node_id == maybe_dummy_payee_node_id { continue 'path_construction; }
2071 // Otherwise, since the current target node is not us,
2072 // keep "unrolling" the payment graph from payee to payer by
2073 // finding a way to reach the current target from the payer side.
2074 match network_nodes.get(&node_id) {
2077 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
2078 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
2079 total_cltv_delta, path_length_to_node);
2085 if !found_new_path && channel_saturation_pow_half != 0 {
2086 channel_saturation_pow_half = 0;
2087 continue 'paths_collection;
2089 // If we don't support MPP, no use trying to gather more value ever.
2090 break 'paths_collection;
2094 // Stop either when the recommended value is reached or if no new path was found in this
2096 // In the latter case, making another path finding attempt won't help,
2097 // because we deterministically terminated the search due to low liquidity.
2098 if !found_new_path && channel_saturation_pow_half != 0 {
2099 channel_saturation_pow_half = 0;
2100 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
2101 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
2102 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
2103 break 'paths_collection;
2104 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
2105 // Further, if this was our first walk of the graph, and we weren't limited by an
2106 // htlc_minimum_msat, return immediately because this path should suffice. If we were
2107 // limited by an htlc_minimum_msat value, find another path with a higher value,
2108 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
2109 // still keeping a lower total fee than this path.
2110 if !hit_minimum_limit {
2111 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
2112 break 'paths_collection;
2114 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
2115 path_value_msat = recommended_value_msat;
2120 if payment_paths.len() == 0 {
2121 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2124 if already_collected_value_msat < final_value_msat {
2125 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2129 let mut selected_route = payment_paths;
2131 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
2132 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
2134 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
2135 // the value they contribute towards the payment amount.
2136 // We sort in descending order as we will remove from the front in `retain`, next.
2137 selected_route.sort_unstable_by(|a, b|
2138 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
2139 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
2142 // We should make sure that at least 1 path left.
2143 let mut paths_left = selected_route.len();
2144 selected_route.retain(|path| {
2145 if paths_left == 1 {
2148 let path_value_msat = path.get_value_msat();
2149 if path_value_msat <= overpaid_value_msat {
2150 overpaid_value_msat -= path_value_msat;
2156 debug_assert!(selected_route.len() > 0);
2158 if overpaid_value_msat != 0 {
2160 // Now, subtract the remaining overpaid value from the most-expensive path.
2161 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
2162 // so that the sender pays less fees overall. And also htlc_minimum_msat.
2163 selected_route.sort_unstable_by(|a, b| {
2164 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2165 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2166 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
2168 let expensive_payment_path = selected_route.first_mut().unwrap();
2170 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
2171 // can't go negative.
2172 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
2173 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
2177 // Sort by the path itself and combine redundant paths.
2178 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
2179 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
2181 selected_route.sort_unstable_by_key(|path| {
2182 let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
2183 debug_assert!(path.hops.len() <= key.len());
2184 for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
2189 for idx in 0..(selected_route.len() - 1) {
2190 if idx + 1 >= selected_route.len() { break; }
2191 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
2192 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
2193 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
2194 selected_route[idx].update_value_and_recompute_fees(new_value);
2195 selected_route.remove(idx + 1);
2199 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
2200 for payment_path in selected_route {
2201 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
2203 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)})?,
2204 node_features: node_features.clone(),
2205 short_channel_id: payment_hop.candidate.short_channel_id(),
2206 channel_features: payment_hop.candidate.features(),
2207 fee_msat: payment_hop.fee_msat,
2208 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
2210 }).collect::<Vec<_>>();
2211 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
2212 // applicable for the previous hop.
2213 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
2214 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
2216 selected_paths.push(path);
2218 // Make sure we would never create a route with more paths than we allow.
2219 debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
2221 if let Some(node_features) = payment_params.payee.node_features() {
2222 for path in selected_paths.iter_mut() {
2223 if let Ok(route_hop) = path.last_mut().unwrap() {
2224 route_hop.node_features = node_features.clone();
2229 let mut paths: Vec<Path> = Vec::new();
2230 for results_vec in selected_paths {
2231 let mut hops = Vec::with_capacity(results_vec.len());
2232 for res in results_vec { hops.push(res?); }
2233 paths.push(Path { hops, blinded_tail: None });
2237 payment_params: Some(payment_params.clone()),
2239 log_info!(logger, "Got route: {}", log_route!(route));
2243 // When an adversarial intermediary node observes a payment, it may be able to infer its
2244 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
2245 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
2246 // payment path by adding a randomized 'shadow route' offset to the final hop.
2247 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
2248 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
2250 let network_channels = network_graph.channels();
2251 let network_nodes = network_graph.nodes();
2253 for path in route.paths.iter_mut() {
2254 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
2256 // Remember the last three nodes of the random walk and avoid looping back on them.
2257 // Init with the last three nodes from the actual path, if possible.
2258 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
2259 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(2)).unwrap().pubkey),
2260 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(3)).unwrap().pubkey)];
2262 // Choose the last publicly known node as the starting point for the random walk.
2263 let mut cur_hop: Option<NodeId> = None;
2264 let mut path_nonce = [0u8; 12];
2265 if let Some(starting_hop) = path.hops.iter().rev()
2266 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
2267 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
2268 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
2271 // Init PRNG with the path-dependant nonce, which is static for private paths.
2272 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
2273 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
2275 // Pick a random path length in [1 .. 3]
2276 prng.process_in_place(&mut random_path_bytes);
2277 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
2279 for random_hop in 0..random_walk_length {
2280 // If we don't find a suitable offset in the public network graph, we default to
2281 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2282 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
2284 if let Some(cur_node_id) = cur_hop {
2285 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
2286 // Randomly choose the next unvisited hop.
2287 prng.process_in_place(&mut random_path_bytes);
2288 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
2289 .checked_rem(cur_node.channels.len())
2290 .and_then(|index| cur_node.channels.get(index))
2291 .and_then(|id| network_channels.get(id)) {
2292 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
2293 if !nodes_to_avoid.iter().any(|x| x == next_id) {
2294 nodes_to_avoid[random_hop] = *next_id;
2295 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
2296 cur_hop = Some(*next_id);
2303 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
2304 .checked_add(random_hop_offset)
2305 .unwrap_or(shadow_ctlv_expiry_delta_offset);
2308 // Limit the total offset to reduce the worst-case locked liquidity timevalue
2309 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
2310 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
2312 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
2313 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2314 let path_total_cltv_expiry_delta: u32 = path.hops.iter().map(|h| h.cltv_expiry_delta).sum();
2315 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
2316 max_path_offset = cmp::max(
2317 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
2318 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
2319 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
2321 // Add 'shadow' CLTV offset to the final hop
2322 if let Some(tail) = path.blinded_tail.as_mut() {
2323 tail.excess_final_cltv_expiry_delta = tail.excess_final_cltv_expiry_delta
2324 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(tail.excess_final_cltv_expiry_delta);
2326 if let Some(last_hop) = path.hops.last_mut() {
2327 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
2328 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
2333 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
2334 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
2336 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
2337 pub fn build_route_from_hops<L: Deref, GL: Deref>(
2338 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
2339 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
2340 ) -> Result<Route, LightningError>
2341 where L::Target: Logger, GL::Target: Logger {
2342 let graph_lock = network_graph.read_only();
2343 let mut route = build_route_from_hops_internal(
2344 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
2345 route_params.final_value_msat, logger, random_seed_bytes)?;
2346 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
2350 fn build_route_from_hops_internal<L: Deref>(
2351 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
2352 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, logger: L,
2353 random_seed_bytes: &[u8; 32]
2354 ) -> Result<Route, LightningError> where L::Target: Logger {
2357 our_node_id: NodeId,
2358 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
2361 impl Score for HopScorer {
2362 type ScoreParams = ();
2363 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
2364 _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
2366 let mut cur_id = self.our_node_id;
2367 for i in 0..self.hop_ids.len() {
2368 if let Some(next_id) = self.hop_ids[i] {
2369 if cur_id == *source && next_id == *target {
2380 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2382 fn payment_path_successful(&mut self, _path: &Path) {}
2384 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2386 fn probe_successful(&mut self, _path: &Path) {}
2389 impl<'a> Writeable for HopScorer {
2391 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
2396 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
2397 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
2400 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
2401 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
2402 for i in 0..hops.len() {
2403 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
2406 let scorer = HopScorer { our_node_id, hop_ids };
2408 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
2409 logger, &scorer, &(), random_seed_bytes)
2414 use crate::blinded_path::{BlindedHop, BlindedPath};
2415 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
2416 use crate::routing::utxo::UtxoResult;
2417 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
2418 BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
2419 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
2420 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
2421 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
2422 use crate::chain::transaction::OutPoint;
2423 use crate::sign::EntropySource;
2424 use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
2425 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
2426 use crate::ln::channelmanager;
2427 use crate::util::config::UserConfig;
2428 use crate::util::test_utils as ln_test_utils;
2429 use crate::util::chacha20::ChaCha20;
2430 use crate::util::ser::{Readable, Writeable};
2432 use crate::util::ser::Writer;
2434 use bitcoin::hashes::Hash;
2435 use bitcoin::network::constants::Network;
2436 use bitcoin::blockdata::constants::genesis_block;
2437 use bitcoin::blockdata::script::Builder;
2438 use bitcoin::blockdata::opcodes;
2439 use bitcoin::blockdata::transaction::TxOut;
2443 use bitcoin::secp256k1::{PublicKey,SecretKey};
2444 use bitcoin::secp256k1::Secp256k1;
2446 use crate::io::Cursor;
2447 use crate::prelude::*;
2448 use crate::sync::Arc;
2450 use core::convert::TryInto;
2452 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
2453 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
2454 channelmanager::ChannelDetails {
2455 channel_id: [0; 32],
2456 counterparty: channelmanager::ChannelCounterparty {
2459 unspendable_punishment_reserve: 0,
2460 forwarding_info: None,
2461 outbound_htlc_minimum_msat: None,
2462 outbound_htlc_maximum_msat: None,
2464 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2467 outbound_scid_alias: None,
2468 inbound_scid_alias: None,
2469 channel_value_satoshis: 0,
2472 outbound_capacity_msat,
2473 next_outbound_htlc_limit_msat: outbound_capacity_msat,
2474 inbound_capacity_msat: 42,
2475 unspendable_punishment_reserve: None,
2476 confirmations_required: None,
2477 confirmations: None,
2478 force_close_spend_delay: None,
2479 is_outbound: true, is_channel_ready: true,
2480 is_usable: true, is_public: true,
2481 inbound_htlc_minimum_msat: None,
2482 inbound_htlc_maximum_msat: None,
2484 feerate_sat_per_1000_weight: None
2489 fn simple_route_test() {
2490 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2491 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2492 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2493 let scorer = ln_test_utils::TestScorer::new();
2494 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2495 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2497 // Simple route to 2 via 1
2499 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) {
2500 assert_eq!(err, "Cannot send a payment of 0 msat");
2501 } else { panic!(); }
2503 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2504 assert_eq!(route.paths[0].hops.len(), 2);
2506 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2507 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2508 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
2509 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2510 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2511 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2513 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2514 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2515 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2516 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2517 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2518 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2522 fn invalid_first_hop_test() {
2523 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2524 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2525 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2526 let scorer = ln_test_utils::TestScorer::new();
2527 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2528 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2530 // Simple route to 2 via 1
2532 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2534 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2535 get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2536 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2537 } else { panic!(); }
2539 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2540 assert_eq!(route.paths[0].hops.len(), 2);
2544 fn htlc_minimum_test() {
2545 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2546 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2547 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2548 let scorer = ln_test_utils::TestScorer::new();
2549 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2550 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2552 // Simple route to 2 via 1
2554 // Disable other paths
2555 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2556 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2557 short_channel_id: 12,
2559 flags: 2, // to disable
2560 cltv_expiry_delta: 0,
2561 htlc_minimum_msat: 0,
2562 htlc_maximum_msat: MAX_VALUE_MSAT,
2564 fee_proportional_millionths: 0,
2565 excess_data: Vec::new()
2567 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2568 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2569 short_channel_id: 3,
2571 flags: 2, // to disable
2572 cltv_expiry_delta: 0,
2573 htlc_minimum_msat: 0,
2574 htlc_maximum_msat: MAX_VALUE_MSAT,
2576 fee_proportional_millionths: 0,
2577 excess_data: Vec::new()
2579 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2580 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2581 short_channel_id: 13,
2583 flags: 2, // to disable
2584 cltv_expiry_delta: 0,
2585 htlc_minimum_msat: 0,
2586 htlc_maximum_msat: MAX_VALUE_MSAT,
2588 fee_proportional_millionths: 0,
2589 excess_data: Vec::new()
2591 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2592 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2593 short_channel_id: 6,
2595 flags: 2, // to disable
2596 cltv_expiry_delta: 0,
2597 htlc_minimum_msat: 0,
2598 htlc_maximum_msat: MAX_VALUE_MSAT,
2600 fee_proportional_millionths: 0,
2601 excess_data: Vec::new()
2603 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2604 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2605 short_channel_id: 7,
2607 flags: 2, // to disable
2608 cltv_expiry_delta: 0,
2609 htlc_minimum_msat: 0,
2610 htlc_maximum_msat: MAX_VALUE_MSAT,
2612 fee_proportional_millionths: 0,
2613 excess_data: Vec::new()
2616 // Check against amount_to_transfer_over_msat.
2617 // Set minimal HTLC of 200_000_000 msat.
2618 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2619 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2620 short_channel_id: 2,
2623 cltv_expiry_delta: 0,
2624 htlc_minimum_msat: 200_000_000,
2625 htlc_maximum_msat: MAX_VALUE_MSAT,
2627 fee_proportional_millionths: 0,
2628 excess_data: Vec::new()
2631 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2633 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2634 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2635 short_channel_id: 4,
2638 cltv_expiry_delta: 0,
2639 htlc_minimum_msat: 0,
2640 htlc_maximum_msat: 199_999_999,
2642 fee_proportional_millionths: 0,
2643 excess_data: Vec::new()
2646 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2647 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) {
2648 assert_eq!(err, "Failed to find a path to the given destination");
2649 } else { panic!(); }
2651 // Lift the restriction on the first hop.
2652 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2653 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2654 short_channel_id: 2,
2657 cltv_expiry_delta: 0,
2658 htlc_minimum_msat: 0,
2659 htlc_maximum_msat: MAX_VALUE_MSAT,
2661 fee_proportional_millionths: 0,
2662 excess_data: Vec::new()
2665 // A payment above the minimum should pass
2666 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2667 assert_eq!(route.paths[0].hops.len(), 2);
2671 fn htlc_minimum_overpay_test() {
2672 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2673 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2674 let config = UserConfig::default();
2675 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
2676 let scorer = ln_test_utils::TestScorer::new();
2677 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2678 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2680 // A route to node#2 via two paths.
2681 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2682 // Thus, they can't send 60 without overpaying.
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: 35_000,
2690 htlc_maximum_msat: 40_000,
2692 fee_proportional_millionths: 0,
2693 excess_data: Vec::new()
2695 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2696 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2697 short_channel_id: 12,
2700 cltv_expiry_delta: 0,
2701 htlc_minimum_msat: 35_000,
2702 htlc_maximum_msat: 40_000,
2704 fee_proportional_millionths: 0,
2705 excess_data: Vec::new()
2709 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2710 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2711 short_channel_id: 13,
2714 cltv_expiry_delta: 0,
2715 htlc_minimum_msat: 0,
2716 htlc_maximum_msat: MAX_VALUE_MSAT,
2718 fee_proportional_millionths: 0,
2719 excess_data: Vec::new()
2721 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2722 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2723 short_channel_id: 4,
2726 cltv_expiry_delta: 0,
2727 htlc_minimum_msat: 0,
2728 htlc_maximum_msat: MAX_VALUE_MSAT,
2730 fee_proportional_millionths: 0,
2731 excess_data: Vec::new()
2734 // Disable other paths
2735 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2736 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2737 short_channel_id: 1,
2739 flags: 2, // to disable
2740 cltv_expiry_delta: 0,
2741 htlc_minimum_msat: 0,
2742 htlc_maximum_msat: MAX_VALUE_MSAT,
2744 fee_proportional_millionths: 0,
2745 excess_data: Vec::new()
2748 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2749 // Overpay fees to hit htlc_minimum_msat.
2750 let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
2751 // TODO: this could be better balanced to overpay 10k and not 15k.
2752 assert_eq!(overpaid_fees, 15_000);
2754 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2755 // while taking even more fee to match htlc_minimum_msat.
2756 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2757 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2758 short_channel_id: 12,
2761 cltv_expiry_delta: 0,
2762 htlc_minimum_msat: 65_000,
2763 htlc_maximum_msat: 80_000,
2765 fee_proportional_millionths: 0,
2766 excess_data: Vec::new()
2768 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2769 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2770 short_channel_id: 2,
2773 cltv_expiry_delta: 0,
2774 htlc_minimum_msat: 0,
2775 htlc_maximum_msat: MAX_VALUE_MSAT,
2777 fee_proportional_millionths: 0,
2778 excess_data: Vec::new()
2780 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2781 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2782 short_channel_id: 4,
2785 cltv_expiry_delta: 0,
2786 htlc_minimum_msat: 0,
2787 htlc_maximum_msat: MAX_VALUE_MSAT,
2789 fee_proportional_millionths: 100_000,
2790 excess_data: Vec::new()
2793 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2794 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2795 assert_eq!(route.paths.len(), 1);
2796 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
2797 let fees = route.paths[0].hops[0].fee_msat;
2798 assert_eq!(fees, 5_000);
2800 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2801 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2802 // the other channel.
2803 assert_eq!(route.paths.len(), 1);
2804 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2805 let fees = route.paths[0].hops[0].fee_msat;
2806 assert_eq!(fees, 5_000);
2810 fn disable_channels_test() {
2811 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2812 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2813 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2814 let scorer = ln_test_utils::TestScorer::new();
2815 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2816 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2818 // // Disable channels 4 and 12 by flags=2
2819 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2820 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2821 short_channel_id: 4,
2823 flags: 2, // to disable
2824 cltv_expiry_delta: 0,
2825 htlc_minimum_msat: 0,
2826 htlc_maximum_msat: MAX_VALUE_MSAT,
2828 fee_proportional_millionths: 0,
2829 excess_data: Vec::new()
2831 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2832 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2833 short_channel_id: 12,
2835 flags: 2, // to disable
2836 cltv_expiry_delta: 0,
2837 htlc_minimum_msat: 0,
2838 htlc_maximum_msat: MAX_VALUE_MSAT,
2840 fee_proportional_millionths: 0,
2841 excess_data: Vec::new()
2844 // If all the channels require some features we don't understand, route should fail
2845 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) {
2846 assert_eq!(err, "Failed to find a path to the given destination");
2847 } else { panic!(); }
2849 // If we specify a channel to node7, that overrides our local channel view and that gets used
2850 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2851 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();
2852 assert_eq!(route.paths[0].hops.len(), 2);
2854 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2855 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2856 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2857 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2858 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2859 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2861 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2862 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2863 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2864 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2865 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2866 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2870 fn disable_node_test() {
2871 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2872 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2873 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2874 let scorer = ln_test_utils::TestScorer::new();
2875 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2876 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2878 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2879 let mut unknown_features = NodeFeatures::empty();
2880 unknown_features.set_unknown_feature_required();
2881 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2882 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2883 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2885 // If all nodes require some features we don't understand, route should fail
2886 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) {
2887 assert_eq!(err, "Failed to find a path to the given destination");
2888 } else { panic!(); }
2890 // If we specify a channel to node7, that overrides our local channel view and that gets used
2891 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2892 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();
2893 assert_eq!(route.paths[0].hops.len(), 2);
2895 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2896 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2897 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2898 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2899 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2900 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2902 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2903 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2904 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2905 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2906 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2907 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2909 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2910 // naively) assume that the user checked the feature bits on the invoice, which override
2911 // the node_announcement.
2915 fn our_chans_test() {
2916 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2917 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2918 let scorer = ln_test_utils::TestScorer::new();
2919 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2920 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2922 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2923 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
2924 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2925 assert_eq!(route.paths[0].hops.len(), 3);
2927 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2928 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2929 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2930 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2931 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2932 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2934 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2935 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2936 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2937 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (3 << 4) | 2);
2938 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2939 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2941 assert_eq!(route.paths[0].hops[2].pubkey, nodes[0]);
2942 assert_eq!(route.paths[0].hops[2].short_channel_id, 3);
2943 assert_eq!(route.paths[0].hops[2].fee_msat, 100);
2944 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
2945 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(1));
2946 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(3));
2948 // If we specify a channel to node7, that overrides our local channel view and that gets used
2949 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2950 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2951 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();
2952 assert_eq!(route.paths[0].hops.len(), 2);
2954 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2955 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2956 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2957 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2958 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
2959 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2961 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2962 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2963 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2964 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2965 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2966 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2969 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2970 let zero_fees = RoutingFees {
2972 proportional_millionths: 0,
2974 vec![RouteHint(vec![RouteHintHop {
2975 src_node_id: nodes[3],
2976 short_channel_id: 8,
2978 cltv_expiry_delta: (8 << 4) | 1,
2979 htlc_minimum_msat: None,
2980 htlc_maximum_msat: None,
2982 ]), RouteHint(vec![RouteHintHop {
2983 src_node_id: nodes[4],
2984 short_channel_id: 9,
2987 proportional_millionths: 0,
2989 cltv_expiry_delta: (9 << 4) | 1,
2990 htlc_minimum_msat: None,
2991 htlc_maximum_msat: None,
2992 }]), RouteHint(vec![RouteHintHop {
2993 src_node_id: nodes[5],
2994 short_channel_id: 10,
2996 cltv_expiry_delta: (10 << 4) | 1,
2997 htlc_minimum_msat: None,
2998 htlc_maximum_msat: None,
3002 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3003 let zero_fees = RoutingFees {
3005 proportional_millionths: 0,
3007 vec![RouteHint(vec![RouteHintHop {
3008 src_node_id: nodes[2],
3009 short_channel_id: 5,
3012 proportional_millionths: 0,
3014 cltv_expiry_delta: (5 << 4) | 1,
3015 htlc_minimum_msat: None,
3016 htlc_maximum_msat: None,
3018 src_node_id: nodes[3],
3019 short_channel_id: 8,
3021 cltv_expiry_delta: (8 << 4) | 1,
3022 htlc_minimum_msat: None,
3023 htlc_maximum_msat: None,
3025 ]), RouteHint(vec![RouteHintHop {
3026 src_node_id: nodes[4],
3027 short_channel_id: 9,
3030 proportional_millionths: 0,
3032 cltv_expiry_delta: (9 << 4) | 1,
3033 htlc_minimum_msat: None,
3034 htlc_maximum_msat: None,
3035 }]), RouteHint(vec![RouteHintHop {
3036 src_node_id: nodes[5],
3037 short_channel_id: 10,
3039 cltv_expiry_delta: (10 << 4) | 1,
3040 htlc_minimum_msat: None,
3041 htlc_maximum_msat: None,
3046 fn partial_route_hint_test() {
3047 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3048 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3049 let scorer = ln_test_utils::TestScorer::new();
3050 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3051 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3053 // Simple test across 2, 3, 5, and 4 via a last_hop channel
3054 // Tests the behaviour when the RouteHint contains a suboptimal hop.
3055 // RouteHint may be partially used by the algo to build the best path.
3057 // First check that last hop can't have its source as the payee.
3058 let invalid_last_hop = RouteHint(vec![RouteHintHop {
3059 src_node_id: nodes[6],
3060 short_channel_id: 8,
3063 proportional_millionths: 0,
3065 cltv_expiry_delta: (8 << 4) | 1,
3066 htlc_minimum_msat: None,
3067 htlc_maximum_msat: None,
3070 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
3071 invalid_last_hops.push(invalid_last_hop);
3073 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops).unwrap();
3074 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) {
3075 assert_eq!(err, "Route hint cannot have the payee as the source.");
3076 } else { panic!(); }
3079 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
3080 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3081 assert_eq!(route.paths[0].hops.len(), 5);
3083 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3084 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3085 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3086 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3087 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3088 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3090 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3091 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3092 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3093 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3094 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3095 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3097 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3098 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3099 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3100 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3101 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3102 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3104 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3105 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3106 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3107 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3108 // If we have a peer in the node map, we'll use their features here since we don't have
3109 // a way of figuring out their features from the invoice:
3110 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3111 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3113 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3114 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3115 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3116 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3117 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3118 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3121 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3122 let zero_fees = RoutingFees {
3124 proportional_millionths: 0,
3126 vec![RouteHint(vec![RouteHintHop {
3127 src_node_id: nodes[3],
3128 short_channel_id: 8,
3130 cltv_expiry_delta: (8 << 4) | 1,
3131 htlc_minimum_msat: None,
3132 htlc_maximum_msat: None,
3133 }]), RouteHint(vec![
3135 ]), RouteHint(vec![RouteHintHop {
3136 src_node_id: nodes[5],
3137 short_channel_id: 10,
3139 cltv_expiry_delta: (10 << 4) | 1,
3140 htlc_minimum_msat: None,
3141 htlc_maximum_msat: None,
3146 fn ignores_empty_last_hops_test() {
3147 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3148 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3149 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes)).unwrap();
3150 let scorer = ln_test_utils::TestScorer::new();
3151 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3152 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3154 // Test handling of an empty RouteHint passed in Invoice.
3156 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3157 assert_eq!(route.paths[0].hops.len(), 5);
3159 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3160 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3161 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3162 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3163 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3164 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3166 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3167 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3168 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3169 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3170 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3171 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3173 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3174 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3175 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3176 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3177 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3178 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3180 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3181 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3182 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3183 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3184 // If we have a peer in the node map, we'll use their features here since we don't have
3185 // a way of figuring out their features from the invoice:
3186 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3187 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3189 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3190 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3191 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3192 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3193 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3194 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3197 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3199 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3200 let zero_fees = RoutingFees {
3202 proportional_millionths: 0,
3204 vec![RouteHint(vec![RouteHintHop {
3205 src_node_id: hint_hops[0],
3206 short_channel_id: 0xff00,
3209 proportional_millionths: 0,
3211 cltv_expiry_delta: (5 << 4) | 1,
3212 htlc_minimum_msat: None,
3213 htlc_maximum_msat: None,
3215 src_node_id: hint_hops[1],
3216 short_channel_id: 0xff01,
3218 cltv_expiry_delta: (8 << 4) | 1,
3219 htlc_minimum_msat: None,
3220 htlc_maximum_msat: None,
3225 fn multi_hint_last_hops_test() {
3226 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3227 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3228 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3229 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3230 let scorer = ln_test_utils::TestScorer::new();
3231 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3232 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3233 // Test through channels 2, 3, 0xff00, 0xff01.
3234 // Test shows that multiple hop hints are considered.
3236 // Disabling channels 6 & 7 by flags=2
3237 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3238 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3239 short_channel_id: 6,
3241 flags: 2, // to disable
3242 cltv_expiry_delta: 0,
3243 htlc_minimum_msat: 0,
3244 htlc_maximum_msat: MAX_VALUE_MSAT,
3246 fee_proportional_millionths: 0,
3247 excess_data: Vec::new()
3249 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3250 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3251 short_channel_id: 7,
3253 flags: 2, // to disable
3254 cltv_expiry_delta: 0,
3255 htlc_minimum_msat: 0,
3256 htlc_maximum_msat: MAX_VALUE_MSAT,
3258 fee_proportional_millionths: 0,
3259 excess_data: Vec::new()
3262 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3263 assert_eq!(route.paths[0].hops.len(), 4);
3265 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3266 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3267 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3268 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3269 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3270 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3272 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3273 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3274 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3275 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3276 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3277 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3279 assert_eq!(route.paths[0].hops[2].pubkey, nodes[3]);
3280 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3281 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3282 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3283 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(4));
3284 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3286 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3287 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3288 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3289 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3290 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3291 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3295 fn private_multi_hint_last_hops_test() {
3296 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3297 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3299 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3300 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3302 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3303 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3304 let scorer = ln_test_utils::TestScorer::new();
3305 // Test through channels 2, 3, 0xff00, 0xff01.
3306 // Test shows that multiple hop hints are considered.
3308 // Disabling channels 6 & 7 by flags=2
3309 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3310 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3311 short_channel_id: 6,
3313 flags: 2, // to disable
3314 cltv_expiry_delta: 0,
3315 htlc_minimum_msat: 0,
3316 htlc_maximum_msat: MAX_VALUE_MSAT,
3318 fee_proportional_millionths: 0,
3319 excess_data: Vec::new()
3321 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3323 short_channel_id: 7,
3325 flags: 2, // to disable
3326 cltv_expiry_delta: 0,
3327 htlc_minimum_msat: 0,
3328 htlc_maximum_msat: MAX_VALUE_MSAT,
3330 fee_proportional_millionths: 0,
3331 excess_data: Vec::new()
3334 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &[42u8; 32]).unwrap();
3335 assert_eq!(route.paths[0].hops.len(), 4);
3337 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3338 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3339 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3340 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3341 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3342 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3344 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3345 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3346 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3347 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3348 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3349 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3351 assert_eq!(route.paths[0].hops[2].pubkey, non_announced_pubkey);
3352 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3353 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3354 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3355 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3356 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3358 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3359 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3360 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3361 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3362 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3363 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3366 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3367 let zero_fees = RoutingFees {
3369 proportional_millionths: 0,
3371 vec![RouteHint(vec![RouteHintHop {
3372 src_node_id: nodes[4],
3373 short_channel_id: 11,
3375 cltv_expiry_delta: (11 << 4) | 1,
3376 htlc_minimum_msat: None,
3377 htlc_maximum_msat: None,
3379 src_node_id: nodes[3],
3380 short_channel_id: 8,
3382 cltv_expiry_delta: (8 << 4) | 1,
3383 htlc_minimum_msat: None,
3384 htlc_maximum_msat: None,
3385 }]), RouteHint(vec![RouteHintHop {
3386 src_node_id: nodes[4],
3387 short_channel_id: 9,
3390 proportional_millionths: 0,
3392 cltv_expiry_delta: (9 << 4) | 1,
3393 htlc_minimum_msat: None,
3394 htlc_maximum_msat: None,
3395 }]), RouteHint(vec![RouteHintHop {
3396 src_node_id: nodes[5],
3397 short_channel_id: 10,
3399 cltv_expiry_delta: (10 << 4) | 1,
3400 htlc_minimum_msat: None,
3401 htlc_maximum_msat: None,
3406 fn last_hops_with_public_channel_test() {
3407 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3408 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3409 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes)).unwrap();
3410 let scorer = ln_test_utils::TestScorer::new();
3411 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3412 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3413 // This test shows that public routes can be present in the invoice
3414 // which would be handled in the same manner.
3416 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3417 assert_eq!(route.paths[0].hops.len(), 5);
3419 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3420 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3421 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3422 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3423 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3424 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3426 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3427 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3428 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3429 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3430 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3431 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3433 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3434 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3435 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3436 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3437 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3438 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3440 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3441 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3442 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3443 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3444 // If we have a peer in the node map, we'll use their features here since we don't have
3445 // a way of figuring out their features from the invoice:
3446 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3447 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3449 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3450 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3451 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3452 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3453 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3454 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3458 fn our_chans_last_hop_connect_test() {
3459 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3460 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3461 let scorer = ln_test_utils::TestScorer::new();
3462 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3463 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3465 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3466 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3467 let mut last_hops = last_hops(&nodes);
3468 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3469 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();
3470 assert_eq!(route.paths[0].hops.len(), 2);
3472 assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
3473 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3474 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
3475 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3476 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3477 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3479 assert_eq!(route.paths[0].hops[1].pubkey, nodes[6]);
3480 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3481 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3482 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3483 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3484 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3486 last_hops[0].0[0].fees.base_msat = 1000;
3488 // Revert to via 6 as the fee on 8 goes up
3489 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops).unwrap();
3490 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3491 assert_eq!(route.paths[0].hops.len(), 4);
3493 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3494 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3495 assert_eq!(route.paths[0].hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
3496 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3497 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3498 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3500 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3501 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3502 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3503 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (7 << 4) | 1);
3504 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3505 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3507 assert_eq!(route.paths[0].hops[2].pubkey, nodes[5]);
3508 assert_eq!(route.paths[0].hops[2].short_channel_id, 7);
3509 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3510 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (10 << 4) | 1);
3511 // If we have a peer in the node map, we'll use their features here since we don't have
3512 // a way of figuring out their features from the invoice:
3513 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
3514 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(7));
3516 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3517 assert_eq!(route.paths[0].hops[3].short_channel_id, 10);
3518 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3519 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3520 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3521 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3523 // ...but still use 8 for larger payments as 6 has a variable feerate
3524 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3525 assert_eq!(route.paths[0].hops.len(), 5);
3527 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3528 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3529 assert_eq!(route.paths[0].hops[0].fee_msat, 3000);
3530 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3531 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3532 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3534 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3535 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3536 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3537 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3538 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3539 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3541 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3542 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3543 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3544 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3545 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3546 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3548 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3549 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3550 assert_eq!(route.paths[0].hops[3].fee_msat, 1000);
3551 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3552 // If we have a peer in the node map, we'll use their features here since we don't have
3553 // a way of figuring out their features from the invoice:
3554 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3555 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3557 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3558 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3559 assert_eq!(route.paths[0].hops[4].fee_msat, 2000);
3560 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3561 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3562 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3565 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> {
3566 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3567 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3568 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3570 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3571 let last_hops = RouteHint(vec![RouteHintHop {
3572 src_node_id: middle_node_id,
3573 short_channel_id: 8,
3576 proportional_millionths: last_hop_fee_prop,
3578 cltv_expiry_delta: (8 << 4) | 1,
3579 htlc_minimum_msat: None,
3580 htlc_maximum_msat: last_hop_htlc_max,
3582 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]).unwrap();
3583 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3584 let scorer = ln_test_utils::TestScorer::new();
3585 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3586 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3587 let logger = ln_test_utils::TestLogger::new();
3588 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
3589 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3590 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, &logger, &scorer, &(), &random_seed_bytes);
3595 fn unannounced_path_test() {
3596 // We should be able to send a payment to a destination without any help of a routing graph
3597 // if we have a channel with a common counterparty that appears in the first and last hop
3599 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3601 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3602 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3603 assert_eq!(route.paths[0].hops.len(), 2);
3605 assert_eq!(route.paths[0].hops[0].pubkey, middle_node_id);
3606 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3607 assert_eq!(route.paths[0].hops[0].fee_msat, 1001);
3608 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3609 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &[0b11]);
3610 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3612 assert_eq!(route.paths[0].hops[1].pubkey, target_node_id);
3613 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3614 assert_eq!(route.paths[0].hops[1].fee_msat, 1000000);
3615 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3616 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3617 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3621 fn overflow_unannounced_path_test_liquidity_underflow() {
3622 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3623 // the last-hop had a fee which overflowed a u64, we'd panic.
3624 // This was due to us adding the first-hop from us unconditionally, causing us to think
3625 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3626 // In this test, we previously hit a subtraction underflow due to having less available
3627 // liquidity at the last hop than 0.
3628 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());
3632 fn overflow_unannounced_path_test_feerate_overflow() {
3633 // This tests for the same case as above, except instead of hitting a subtraction
3634 // underflow, we hit a case where the fee charged at a hop overflowed.
3635 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());
3639 fn available_amount_while_routing_test() {
3640 // Tests whether we choose the correct available channel amount while routing.
3642 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3643 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3644 let scorer = ln_test_utils::TestScorer::new();
3645 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3646 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3647 let config = UserConfig::default();
3648 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
3650 // We will use a simple single-path route from
3651 // our node to node2 via node0: channels {1, 3}.
3653 // First disable all other paths.
3654 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3655 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3656 short_channel_id: 2,
3659 cltv_expiry_delta: 0,
3660 htlc_minimum_msat: 0,
3661 htlc_maximum_msat: 100_000,
3663 fee_proportional_millionths: 0,
3664 excess_data: Vec::new()
3666 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3667 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3668 short_channel_id: 12,
3671 cltv_expiry_delta: 0,
3672 htlc_minimum_msat: 0,
3673 htlc_maximum_msat: 100_000,
3675 fee_proportional_millionths: 0,
3676 excess_data: Vec::new()
3679 // Make the first channel (#1) very permissive,
3680 // and we will be testing all limits on the second channel.
3681 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3682 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3683 short_channel_id: 1,
3686 cltv_expiry_delta: 0,
3687 htlc_minimum_msat: 0,
3688 htlc_maximum_msat: 1_000_000_000,
3690 fee_proportional_millionths: 0,
3691 excess_data: Vec::new()
3694 // First, let's see if routing works if we have absolutely no idea about the available amount.
3695 // In this case, it should be set to 250_000 sats.
3696 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3697 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3698 short_channel_id: 3,
3701 cltv_expiry_delta: 0,
3702 htlc_minimum_msat: 0,
3703 htlc_maximum_msat: 250_000_000,
3705 fee_proportional_millionths: 0,
3706 excess_data: Vec::new()
3710 // Attempt to route more than available results in a failure.
3711 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3712 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3713 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3714 } else { panic!(); }
3718 // Now, attempt to route an exact amount we have should be fine.
3719 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, Arc::clone(&logger), &scorer, &(),&random_seed_bytes).unwrap();
3720 assert_eq!(route.paths.len(), 1);
3721 let path = route.paths.last().unwrap();
3722 assert_eq!(path.hops.len(), 2);
3723 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3724 assert_eq!(path.final_value_msat(), 250_000_000);
3727 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3728 // Disable channel #1 and use another first hop.
3729 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3730 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3731 short_channel_id: 1,
3734 cltv_expiry_delta: 0,
3735 htlc_minimum_msat: 0,
3736 htlc_maximum_msat: 1_000_000_000,
3738 fee_proportional_millionths: 0,
3739 excess_data: Vec::new()
3742 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3743 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3746 // Attempt to route more than available results in a failure.
3747 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3748 &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3749 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3750 } else { panic!(); }
3754 // Now, attempt to route an exact amount we have should be fine.
3755 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();
3756 assert_eq!(route.paths.len(), 1);
3757 let path = route.paths.last().unwrap();
3758 assert_eq!(path.hops.len(), 2);
3759 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3760 assert_eq!(path.final_value_msat(), 200_000_000);
3763 // Enable channel #1 back.
3764 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3765 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3766 short_channel_id: 1,
3769 cltv_expiry_delta: 0,
3770 htlc_minimum_msat: 0,
3771 htlc_maximum_msat: 1_000_000_000,
3773 fee_proportional_millionths: 0,
3774 excess_data: Vec::new()
3778 // Now let's see if routing works if we know only htlc_maximum_msat.
3779 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3780 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3781 short_channel_id: 3,
3784 cltv_expiry_delta: 0,
3785 htlc_minimum_msat: 0,
3786 htlc_maximum_msat: 15_000,
3788 fee_proportional_millionths: 0,
3789 excess_data: Vec::new()
3793 // Attempt to route more than available results in a failure.
3794 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3795 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3796 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3797 } else { panic!(); }
3801 // Now, attempt to route an exact amount we have should be fine.
3802 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3803 assert_eq!(route.paths.len(), 1);
3804 let path = route.paths.last().unwrap();
3805 assert_eq!(path.hops.len(), 2);
3806 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3807 assert_eq!(path.final_value_msat(), 15_000);
3810 // Now let's see if routing works if we know only capacity from the UTXO.
3812 // We can't change UTXO capacity on the fly, so we'll disable
3813 // the existing channel and add another one with the capacity we need.
3814 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3815 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3816 short_channel_id: 3,
3819 cltv_expiry_delta: 0,
3820 htlc_minimum_msat: 0,
3821 htlc_maximum_msat: MAX_VALUE_MSAT,
3823 fee_proportional_millionths: 0,
3824 excess_data: Vec::new()
3827 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3828 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3829 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3830 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3831 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3833 *chain_monitor.utxo_ret.lock().unwrap() =
3834 UtxoResult::Sync(Ok(TxOut { value: 15, script_pubkey: good_script.clone() }));
3835 gossip_sync.add_utxo_lookup(Some(chain_monitor));
3837 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3838 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3839 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3840 short_channel_id: 333,
3843 cltv_expiry_delta: (3 << 4) | 1,
3844 htlc_minimum_msat: 0,
3845 htlc_maximum_msat: 15_000,
3847 fee_proportional_millionths: 0,
3848 excess_data: Vec::new()
3850 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3851 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3852 short_channel_id: 333,
3855 cltv_expiry_delta: (3 << 4) | 2,
3856 htlc_minimum_msat: 0,
3857 htlc_maximum_msat: 15_000,
3859 fee_proportional_millionths: 0,
3860 excess_data: Vec::new()
3864 // Attempt to route more than available results in a failure.
3865 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3866 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3867 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3868 } else { panic!(); }
3872 // Now, attempt to route an exact amount we have should be fine.
3873 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3874 assert_eq!(route.paths.len(), 1);
3875 let path = route.paths.last().unwrap();
3876 assert_eq!(path.hops.len(), 2);
3877 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3878 assert_eq!(path.final_value_msat(), 15_000);
3881 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3882 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3883 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3884 short_channel_id: 333,
3887 cltv_expiry_delta: 0,
3888 htlc_minimum_msat: 0,
3889 htlc_maximum_msat: 10_000,
3891 fee_proportional_millionths: 0,
3892 excess_data: Vec::new()
3896 // Attempt to route more than available results in a failure.
3897 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3898 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3899 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3900 } else { panic!(); }
3904 // Now, attempt to route an exact amount we have should be fine.
3905 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3906 assert_eq!(route.paths.len(), 1);
3907 let path = route.paths.last().unwrap();
3908 assert_eq!(path.hops.len(), 2);
3909 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3910 assert_eq!(path.final_value_msat(), 10_000);
3915 fn available_liquidity_last_hop_test() {
3916 // Check that available liquidity properly limits the path even when only
3917 // one of the latter hops is limited.
3918 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3919 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3920 let scorer = ln_test_utils::TestScorer::new();
3921 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3922 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3923 let config = UserConfig::default();
3924 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
3926 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3927 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3928 // Total capacity: 50 sats.
3930 // Disable other potential paths.
3931 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3932 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3933 short_channel_id: 2,
3936 cltv_expiry_delta: 0,
3937 htlc_minimum_msat: 0,
3938 htlc_maximum_msat: 100_000,
3940 fee_proportional_millionths: 0,
3941 excess_data: Vec::new()
3943 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3944 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3945 short_channel_id: 7,
3948 cltv_expiry_delta: 0,
3949 htlc_minimum_msat: 0,
3950 htlc_maximum_msat: 100_000,
3952 fee_proportional_millionths: 0,
3953 excess_data: Vec::new()
3958 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3959 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3960 short_channel_id: 12,
3963 cltv_expiry_delta: 0,
3964 htlc_minimum_msat: 0,
3965 htlc_maximum_msat: 100_000,
3967 fee_proportional_millionths: 0,
3968 excess_data: Vec::new()
3970 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3971 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3972 short_channel_id: 13,
3975 cltv_expiry_delta: 0,
3976 htlc_minimum_msat: 0,
3977 htlc_maximum_msat: 100_000,
3979 fee_proportional_millionths: 0,
3980 excess_data: Vec::new()
3983 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3984 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3985 short_channel_id: 6,
3988 cltv_expiry_delta: 0,
3989 htlc_minimum_msat: 0,
3990 htlc_maximum_msat: 50_000,
3992 fee_proportional_millionths: 0,
3993 excess_data: Vec::new()
3995 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3996 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3997 short_channel_id: 11,
4000 cltv_expiry_delta: 0,
4001 htlc_minimum_msat: 0,
4002 htlc_maximum_msat: 100_000,
4004 fee_proportional_millionths: 0,
4005 excess_data: Vec::new()
4008 // Attempt to route more than available results in a failure.
4009 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4010 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4011 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4012 } else { panic!(); }
4016 // Now, attempt to route 49 sats (just a bit below the capacity).
4017 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4018 assert_eq!(route.paths.len(), 1);
4019 let mut total_amount_paid_msat = 0;
4020 for path in &route.paths {
4021 assert_eq!(path.hops.len(), 4);
4022 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4023 total_amount_paid_msat += path.final_value_msat();
4025 assert_eq!(total_amount_paid_msat, 49_000);
4029 // Attempt to route an exact amount is also fine
4030 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4031 assert_eq!(route.paths.len(), 1);
4032 let mut total_amount_paid_msat = 0;
4033 for path in &route.paths {
4034 assert_eq!(path.hops.len(), 4);
4035 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4036 total_amount_paid_msat += path.final_value_msat();
4038 assert_eq!(total_amount_paid_msat, 50_000);
4043 fn ignore_fee_first_hop_test() {
4044 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4045 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4046 let scorer = ln_test_utils::TestScorer::new();
4047 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4048 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4049 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
4051 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4052 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4053 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4054 short_channel_id: 1,
4057 cltv_expiry_delta: 0,
4058 htlc_minimum_msat: 0,
4059 htlc_maximum_msat: 100_000,
4060 fee_base_msat: 1_000_000,
4061 fee_proportional_millionths: 0,
4062 excess_data: Vec::new()
4064 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4065 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4066 short_channel_id: 3,
4069 cltv_expiry_delta: 0,
4070 htlc_minimum_msat: 0,
4071 htlc_maximum_msat: 50_000,
4073 fee_proportional_millionths: 0,
4074 excess_data: Vec::new()
4078 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4079 assert_eq!(route.paths.len(), 1);
4080 let mut total_amount_paid_msat = 0;
4081 for path in &route.paths {
4082 assert_eq!(path.hops.len(), 2);
4083 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4084 total_amount_paid_msat += path.final_value_msat();
4086 assert_eq!(total_amount_paid_msat, 50_000);
4091 fn simple_mpp_route_test() {
4092 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4093 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4094 let scorer = ln_test_utils::TestScorer::new();
4095 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4096 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4097 let config = UserConfig::default();
4098 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
4099 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4101 // We need a route consisting of 3 paths:
4102 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4103 // To achieve this, the amount being transferred should be around
4104 // the total capacity of these 3 paths.
4106 // First, we set limits on these (previously unlimited) channels.
4107 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4109 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4110 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4111 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4112 short_channel_id: 1,
4115 cltv_expiry_delta: 0,
4116 htlc_minimum_msat: 0,
4117 htlc_maximum_msat: 100_000,
4119 fee_proportional_millionths: 0,
4120 excess_data: Vec::new()
4122 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4123 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4124 short_channel_id: 3,
4127 cltv_expiry_delta: 0,
4128 htlc_minimum_msat: 0,
4129 htlc_maximum_msat: 50_000,
4131 fee_proportional_millionths: 0,
4132 excess_data: Vec::new()
4135 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4136 // (total limit 60).
4137 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4138 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4139 short_channel_id: 12,
4142 cltv_expiry_delta: 0,
4143 htlc_minimum_msat: 0,
4144 htlc_maximum_msat: 60_000,
4146 fee_proportional_millionths: 0,
4147 excess_data: Vec::new()
4149 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4150 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4151 short_channel_id: 13,
4154 cltv_expiry_delta: 0,
4155 htlc_minimum_msat: 0,
4156 htlc_maximum_msat: 60_000,
4158 fee_proportional_millionths: 0,
4159 excess_data: Vec::new()
4162 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4163 // (total capacity 180 sats).
4164 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4165 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4166 short_channel_id: 2,
4169 cltv_expiry_delta: 0,
4170 htlc_minimum_msat: 0,
4171 htlc_maximum_msat: 200_000,
4173 fee_proportional_millionths: 0,
4174 excess_data: Vec::new()
4176 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4177 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4178 short_channel_id: 4,
4181 cltv_expiry_delta: 0,
4182 htlc_minimum_msat: 0,
4183 htlc_maximum_msat: 180_000,
4185 fee_proportional_millionths: 0,
4186 excess_data: Vec::new()
4190 // Attempt to route more than available results in a failure.
4191 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4192 &our_id, &payment_params, &network_graph.read_only(), None, 300_000,
4193 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4194 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4195 } else { panic!(); }
4199 // Attempt to route while setting max_path_count to 0 results in a failure.
4200 let zero_payment_params = payment_params.clone().with_max_path_count(0);
4201 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4202 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100,
4203 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4204 assert_eq!(err, "Can't find a route with no paths allowed.");
4205 } else { panic!(); }
4209 // Attempt to route while setting max_path_count to 3 results in a failure.
4210 // This is the case because the minimal_value_contribution_msat would require each path
4211 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4212 let fail_payment_params = payment_params.clone().with_max_path_count(3);
4213 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4214 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000,
4215 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4216 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4217 } else { panic!(); }
4221 // Now, attempt to route 250 sats (just a bit below the capacity).
4222 // Our algorithm should provide us with these 3 paths.
4223 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4224 250_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4225 assert_eq!(route.paths.len(), 3);
4226 let mut total_amount_paid_msat = 0;
4227 for path in &route.paths {
4228 assert_eq!(path.hops.len(), 2);
4229 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4230 total_amount_paid_msat += path.final_value_msat();
4232 assert_eq!(total_amount_paid_msat, 250_000);
4236 // Attempt to route an exact amount is also fine
4237 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4238 290_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4239 assert_eq!(route.paths.len(), 3);
4240 let mut total_amount_paid_msat = 0;
4241 for path in &route.paths {
4242 assert_eq!(path.hops.len(), 2);
4243 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4244 total_amount_paid_msat += path.final_value_msat();
4246 assert_eq!(total_amount_paid_msat, 290_000);
4251 fn long_mpp_route_test() {
4252 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4253 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4254 let scorer = ln_test_utils::TestScorer::new();
4255 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4256 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4257 let config = UserConfig::default();
4258 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4260 // We need a route consisting of 3 paths:
4261 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4262 // Note that these paths overlap (channels 5, 12, 13).
4263 // We will route 300 sats.
4264 // Each path will have 100 sats capacity, those channels which
4265 // are used twice will have 200 sats capacity.
4267 // Disable other potential paths.
4268 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4269 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4270 short_channel_id: 2,
4273 cltv_expiry_delta: 0,
4274 htlc_minimum_msat: 0,
4275 htlc_maximum_msat: 100_000,
4277 fee_proportional_millionths: 0,
4278 excess_data: Vec::new()
4280 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4281 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4282 short_channel_id: 7,
4285 cltv_expiry_delta: 0,
4286 htlc_minimum_msat: 0,
4287 htlc_maximum_msat: 100_000,
4289 fee_proportional_millionths: 0,
4290 excess_data: Vec::new()
4293 // Path via {node0, node2} is channels {1, 3, 5}.
4294 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4295 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4296 short_channel_id: 1,
4299 cltv_expiry_delta: 0,
4300 htlc_minimum_msat: 0,
4301 htlc_maximum_msat: 100_000,
4303 fee_proportional_millionths: 0,
4304 excess_data: Vec::new()
4306 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4307 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4308 short_channel_id: 3,
4311 cltv_expiry_delta: 0,
4312 htlc_minimum_msat: 0,
4313 htlc_maximum_msat: 100_000,
4315 fee_proportional_millionths: 0,
4316 excess_data: Vec::new()
4319 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4320 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4321 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4323 short_channel_id: 5,
4326 cltv_expiry_delta: 0,
4327 htlc_minimum_msat: 0,
4328 htlc_maximum_msat: 200_000,
4330 fee_proportional_millionths: 0,
4331 excess_data: Vec::new()
4334 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4335 // Add 100 sats to the capacities of {12, 13}, because these channels
4336 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4337 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4338 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4339 short_channel_id: 12,
4342 cltv_expiry_delta: 0,
4343 htlc_minimum_msat: 0,
4344 htlc_maximum_msat: 200_000,
4346 fee_proportional_millionths: 0,
4347 excess_data: Vec::new()
4349 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4350 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4351 short_channel_id: 13,
4354 cltv_expiry_delta: 0,
4355 htlc_minimum_msat: 0,
4356 htlc_maximum_msat: 200_000,
4358 fee_proportional_millionths: 0,
4359 excess_data: Vec::new()
4362 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4363 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4364 short_channel_id: 6,
4367 cltv_expiry_delta: 0,
4368 htlc_minimum_msat: 0,
4369 htlc_maximum_msat: 100_000,
4371 fee_proportional_millionths: 0,
4372 excess_data: Vec::new()
4374 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4375 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4376 short_channel_id: 11,
4379 cltv_expiry_delta: 0,
4380 htlc_minimum_msat: 0,
4381 htlc_maximum_msat: 100_000,
4383 fee_proportional_millionths: 0,
4384 excess_data: Vec::new()
4387 // Path via {node7, node2} is channels {12, 13, 5}.
4388 // We already limited them to 200 sats (they are used twice for 100 sats).
4389 // Nothing to do here.
4392 // Attempt to route more than available results in a failure.
4393 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4394 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4395 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4396 } else { panic!(); }
4400 // Now, attempt to route 300 sats (exact amount we can route).
4401 // Our algorithm should provide us with these 3 paths, 100 sats each.
4402 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4403 assert_eq!(route.paths.len(), 3);
4405 let mut total_amount_paid_msat = 0;
4406 for path in &route.paths {
4407 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4408 total_amount_paid_msat += path.final_value_msat();
4410 assert_eq!(total_amount_paid_msat, 300_000);
4416 fn mpp_cheaper_route_test() {
4417 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4418 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4419 let scorer = ln_test_utils::TestScorer::new();
4420 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4421 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4422 let config = UserConfig::default();
4423 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4425 // This test checks that if we have two cheaper paths and one more expensive path,
4426 // so that liquidity-wise any 2 of 3 combination is sufficient,
4427 // two cheaper paths will be taken.
4428 // These paths have equal available liquidity.
4430 // We need a combination of 3 paths:
4431 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4432 // Note that these paths overlap (channels 5, 12, 13).
4433 // Each path will have 100 sats capacity, those channels which
4434 // are used twice will have 200 sats capacity.
4436 // Disable other potential paths.
4437 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4438 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4439 short_channel_id: 2,
4442 cltv_expiry_delta: 0,
4443 htlc_minimum_msat: 0,
4444 htlc_maximum_msat: 100_000,
4446 fee_proportional_millionths: 0,
4447 excess_data: Vec::new()
4449 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4451 short_channel_id: 7,
4454 cltv_expiry_delta: 0,
4455 htlc_minimum_msat: 0,
4456 htlc_maximum_msat: 100_000,
4458 fee_proportional_millionths: 0,
4459 excess_data: Vec::new()
4462 // Path via {node0, node2} is channels {1, 3, 5}.
4463 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4464 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4465 short_channel_id: 1,
4468 cltv_expiry_delta: 0,
4469 htlc_minimum_msat: 0,
4470 htlc_maximum_msat: 100_000,
4472 fee_proportional_millionths: 0,
4473 excess_data: Vec::new()
4475 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4477 short_channel_id: 3,
4480 cltv_expiry_delta: 0,
4481 htlc_minimum_msat: 0,
4482 htlc_maximum_msat: 100_000,
4484 fee_proportional_millionths: 0,
4485 excess_data: Vec::new()
4488 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4489 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4490 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4491 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4492 short_channel_id: 5,
4495 cltv_expiry_delta: 0,
4496 htlc_minimum_msat: 0,
4497 htlc_maximum_msat: 200_000,
4499 fee_proportional_millionths: 0,
4500 excess_data: Vec::new()
4503 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4504 // Add 100 sats to the capacities of {12, 13}, because these channels
4505 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4506 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4507 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4508 short_channel_id: 12,
4511 cltv_expiry_delta: 0,
4512 htlc_minimum_msat: 0,
4513 htlc_maximum_msat: 200_000,
4515 fee_proportional_millionths: 0,
4516 excess_data: Vec::new()
4518 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4519 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4520 short_channel_id: 13,
4523 cltv_expiry_delta: 0,
4524 htlc_minimum_msat: 0,
4525 htlc_maximum_msat: 200_000,
4527 fee_proportional_millionths: 0,
4528 excess_data: Vec::new()
4531 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4532 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4533 short_channel_id: 6,
4536 cltv_expiry_delta: 0,
4537 htlc_minimum_msat: 0,
4538 htlc_maximum_msat: 100_000,
4539 fee_base_msat: 1_000,
4540 fee_proportional_millionths: 0,
4541 excess_data: Vec::new()
4543 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4544 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4545 short_channel_id: 11,
4548 cltv_expiry_delta: 0,
4549 htlc_minimum_msat: 0,
4550 htlc_maximum_msat: 100_000,
4552 fee_proportional_millionths: 0,
4553 excess_data: Vec::new()
4556 // Path via {node7, node2} is channels {12, 13, 5}.
4557 // We already limited them to 200 sats (they are used twice for 100 sats).
4558 // Nothing to do here.
4561 // Now, attempt to route 180 sats.
4562 // Our algorithm should provide us with these 2 paths.
4563 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4564 assert_eq!(route.paths.len(), 2);
4566 let mut total_value_transferred_msat = 0;
4567 let mut total_paid_msat = 0;
4568 for path in &route.paths {
4569 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4570 total_value_transferred_msat += path.final_value_msat();
4571 for hop in &path.hops {
4572 total_paid_msat += hop.fee_msat;
4575 // If we paid fee, this would be higher.
4576 assert_eq!(total_value_transferred_msat, 180_000);
4577 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4578 assert_eq!(total_fees_paid, 0);
4583 fn fees_on_mpp_route_test() {
4584 // This test makes sure that MPP algorithm properly takes into account
4585 // fees charged on the channels, by making the fees impactful:
4586 // if the fee is not properly accounted for, the behavior is different.
4587 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4588 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4589 let scorer = ln_test_utils::TestScorer::new();
4590 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4591 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4592 let config = UserConfig::default();
4593 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4595 // We need a route consisting of 2 paths:
4596 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4597 // We will route 200 sats, Each path will have 100 sats capacity.
4599 // This test is not particularly stable: e.g.,
4600 // there's a way to route via {node0, node2, node4}.
4601 // It works while pathfinding is deterministic, but can be broken otherwise.
4602 // It's fine to ignore this concern for now.
4604 // Disable other potential paths.
4605 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4606 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4607 short_channel_id: 2,
4610 cltv_expiry_delta: 0,
4611 htlc_minimum_msat: 0,
4612 htlc_maximum_msat: 100_000,
4614 fee_proportional_millionths: 0,
4615 excess_data: Vec::new()
4618 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4619 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4620 short_channel_id: 7,
4623 cltv_expiry_delta: 0,
4624 htlc_minimum_msat: 0,
4625 htlc_maximum_msat: 100_000,
4627 fee_proportional_millionths: 0,
4628 excess_data: Vec::new()
4631 // Path via {node0, node2} is channels {1, 3, 5}.
4632 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4633 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4634 short_channel_id: 1,
4637 cltv_expiry_delta: 0,
4638 htlc_minimum_msat: 0,
4639 htlc_maximum_msat: 100_000,
4641 fee_proportional_millionths: 0,
4642 excess_data: Vec::new()
4644 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4645 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4646 short_channel_id: 3,
4649 cltv_expiry_delta: 0,
4650 htlc_minimum_msat: 0,
4651 htlc_maximum_msat: 100_000,
4653 fee_proportional_millionths: 0,
4654 excess_data: Vec::new()
4657 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4658 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4660 short_channel_id: 5,
4663 cltv_expiry_delta: 0,
4664 htlc_minimum_msat: 0,
4665 htlc_maximum_msat: 100_000,
4667 fee_proportional_millionths: 0,
4668 excess_data: Vec::new()
4671 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4672 // All channels should be 100 sats capacity. But for the fee experiment,
4673 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4674 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4675 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4676 // so no matter how large are other channels,
4677 // the whole path will be limited by 100 sats with just these 2 conditions:
4678 // - channel 12 capacity is 250 sats
4679 // - fee for channel 6 is 150 sats
4680 // Let's test this by enforcing these 2 conditions and removing other limits.
4681 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4682 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4683 short_channel_id: 12,
4686 cltv_expiry_delta: 0,
4687 htlc_minimum_msat: 0,
4688 htlc_maximum_msat: 250_000,
4690 fee_proportional_millionths: 0,
4691 excess_data: Vec::new()
4693 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4694 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4695 short_channel_id: 13,
4698 cltv_expiry_delta: 0,
4699 htlc_minimum_msat: 0,
4700 htlc_maximum_msat: MAX_VALUE_MSAT,
4702 fee_proportional_millionths: 0,
4703 excess_data: Vec::new()
4706 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4707 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4708 short_channel_id: 6,
4711 cltv_expiry_delta: 0,
4712 htlc_minimum_msat: 0,
4713 htlc_maximum_msat: MAX_VALUE_MSAT,
4714 fee_base_msat: 150_000,
4715 fee_proportional_millionths: 0,
4716 excess_data: Vec::new()
4718 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4719 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4720 short_channel_id: 11,
4723 cltv_expiry_delta: 0,
4724 htlc_minimum_msat: 0,
4725 htlc_maximum_msat: MAX_VALUE_MSAT,
4727 fee_proportional_millionths: 0,
4728 excess_data: Vec::new()
4732 // Attempt to route more than available results in a failure.
4733 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4734 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4735 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4736 } else { panic!(); }
4740 // Now, attempt to route 200 sats (exact amount we can route).
4741 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4742 assert_eq!(route.paths.len(), 2);
4744 let mut total_amount_paid_msat = 0;
4745 for path in &route.paths {
4746 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4747 total_amount_paid_msat += path.final_value_msat();
4749 assert_eq!(total_amount_paid_msat, 200_000);
4750 assert_eq!(route.get_total_fees(), 150_000);
4755 fn mpp_with_last_hops() {
4756 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4757 // via a single last-hop route hint, we'd fail to route if we first collected routes
4758 // totaling close but not quite enough to fund the full payment.
4760 // This was because we considered last-hop hints to have exactly the sought payment amount
4761 // instead of the amount we were trying to collect, needlessly limiting our path searching
4762 // at the very first hop.
4764 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4765 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4766 // to only have the remaining to-collect amount in available liquidity.
4768 // This bug appeared in production in some specific channel configurations.
4769 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4770 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4771 let scorer = ln_test_utils::TestScorer::new();
4772 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4773 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4774 let config = UserConfig::default();
4775 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
4776 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4777 src_node_id: nodes[2],
4778 short_channel_id: 42,
4779 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4780 cltv_expiry_delta: 42,
4781 htlc_minimum_msat: None,
4782 htlc_maximum_msat: None,
4783 }])]).unwrap().with_max_channel_saturation_power_of_half(0);
4785 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4786 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4787 // would first use the no-fee route and then fail to find a path along the second route as
4788 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4789 // under 5% of our payment amount.
4790 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4791 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4792 short_channel_id: 1,
4795 cltv_expiry_delta: (5 << 4) | 5,
4796 htlc_minimum_msat: 0,
4797 htlc_maximum_msat: 99_000,
4798 fee_base_msat: u32::max_value(),
4799 fee_proportional_millionths: u32::max_value(),
4800 excess_data: Vec::new()
4802 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4803 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4804 short_channel_id: 2,
4807 cltv_expiry_delta: (5 << 4) | 3,
4808 htlc_minimum_msat: 0,
4809 htlc_maximum_msat: 99_000,
4810 fee_base_msat: u32::max_value(),
4811 fee_proportional_millionths: u32::max_value(),
4812 excess_data: Vec::new()
4814 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4815 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4816 short_channel_id: 4,
4819 cltv_expiry_delta: (4 << 4) | 1,
4820 htlc_minimum_msat: 0,
4821 htlc_maximum_msat: MAX_VALUE_MSAT,
4823 fee_proportional_millionths: 0,
4824 excess_data: Vec::new()
4826 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4827 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4828 short_channel_id: 13,
4830 flags: 0|2, // Channel disabled
4831 cltv_expiry_delta: (13 << 4) | 1,
4832 htlc_minimum_msat: 0,
4833 htlc_maximum_msat: MAX_VALUE_MSAT,
4835 fee_proportional_millionths: 2000000,
4836 excess_data: Vec::new()
4839 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4841 let mut route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4842 assert_eq!(route.paths.len(), 2);
4843 route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
4844 // Paths are manually ordered ordered by SCID, so:
4845 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4846 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
4847 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
4848 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
4849 assert_eq!(route.paths[0].hops[2].fee_msat, 99_000);
4850 assert_eq!(route.paths[1].hops[0].short_channel_id, 2);
4851 assert_eq!(route.paths[1].hops[0].fee_msat, 1);
4852 assert_eq!(route.paths[1].hops[2].fee_msat, 1_000);
4853 assert_eq!(route.get_total_fees(), 1);
4854 assert_eq!(route.get_total_amount(), 100_000);
4858 fn drop_lowest_channel_mpp_route_test() {
4859 // This test checks that low-capacity channel is dropped when after
4860 // path finding we realize that we found more capacity than we need.
4861 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4862 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4863 let scorer = ln_test_utils::TestScorer::new();
4864 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4865 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4866 let config = UserConfig::default();
4867 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
4868 .with_max_channel_saturation_power_of_half(0);
4870 // We need a route consisting of 3 paths:
4871 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4873 // The first and the second paths should be sufficient, but the third should be
4874 // cheaper, so that we select it but drop later.
4876 // First, we set limits on these (previously unlimited) channels.
4877 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4879 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4880 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4881 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4882 short_channel_id: 1,
4885 cltv_expiry_delta: 0,
4886 htlc_minimum_msat: 0,
4887 htlc_maximum_msat: 100_000,
4889 fee_proportional_millionths: 0,
4890 excess_data: Vec::new()
4892 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4893 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4894 short_channel_id: 3,
4897 cltv_expiry_delta: 0,
4898 htlc_minimum_msat: 0,
4899 htlc_maximum_msat: 50_000,
4901 fee_proportional_millionths: 0,
4902 excess_data: Vec::new()
4905 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4906 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4907 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4908 short_channel_id: 12,
4911 cltv_expiry_delta: 0,
4912 htlc_minimum_msat: 0,
4913 htlc_maximum_msat: 60_000,
4915 fee_proportional_millionths: 0,
4916 excess_data: Vec::new()
4918 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4919 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4920 short_channel_id: 13,
4923 cltv_expiry_delta: 0,
4924 htlc_minimum_msat: 0,
4925 htlc_maximum_msat: 60_000,
4927 fee_proportional_millionths: 0,
4928 excess_data: Vec::new()
4931 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4932 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4933 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4934 short_channel_id: 2,
4937 cltv_expiry_delta: 0,
4938 htlc_minimum_msat: 0,
4939 htlc_maximum_msat: 20_000,
4941 fee_proportional_millionths: 0,
4942 excess_data: Vec::new()
4944 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4945 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4946 short_channel_id: 4,
4949 cltv_expiry_delta: 0,
4950 htlc_minimum_msat: 0,
4951 htlc_maximum_msat: 20_000,
4953 fee_proportional_millionths: 0,
4954 excess_data: Vec::new()
4958 // Attempt to route more than available results in a failure.
4959 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4960 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4961 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4962 } else { panic!(); }
4966 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4967 // Our algorithm should provide us with these 3 paths.
4968 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4969 assert_eq!(route.paths.len(), 3);
4970 let mut total_amount_paid_msat = 0;
4971 for path in &route.paths {
4972 assert_eq!(path.hops.len(), 2);
4973 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4974 total_amount_paid_msat += path.final_value_msat();
4976 assert_eq!(total_amount_paid_msat, 125_000);
4980 // Attempt to route without the last small cheap channel
4981 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4982 assert_eq!(route.paths.len(), 2);
4983 let mut total_amount_paid_msat = 0;
4984 for path in &route.paths {
4985 assert_eq!(path.hops.len(), 2);
4986 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4987 total_amount_paid_msat += path.final_value_msat();
4989 assert_eq!(total_amount_paid_msat, 90_000);
4994 fn min_criteria_consistency() {
4995 // Test that we don't use an inconsistent metric between updating and walking nodes during
4996 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4997 // was updated with a different criterion from the heap sorting, resulting in loops in
4998 // calculated paths. We test for that specific case here.
5000 // We construct a network that looks like this:
5002 // node2 -1(3)2- node3
5006 // node1 -1(5)2- node4 -1(1)2- node6
5012 // We create a loop on the side of our real path - our destination is node 6, with a
5013 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
5014 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
5015 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
5016 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
5017 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
5018 // "previous hop" being set to node 3, creating a loop in the path.
5019 let secp_ctx = Secp256k1::new();
5020 let logger = Arc::new(ln_test_utils::TestLogger::new());
5021 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
5022 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
5023 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5024 let scorer = ln_test_utils::TestScorer::new();
5025 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5026 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5027 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
5029 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
5030 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5031 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5032 short_channel_id: 6,
5035 cltv_expiry_delta: (6 << 4) | 0,
5036 htlc_minimum_msat: 0,
5037 htlc_maximum_msat: MAX_VALUE_MSAT,
5039 fee_proportional_millionths: 0,
5040 excess_data: Vec::new()
5042 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
5044 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5045 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5046 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5047 short_channel_id: 5,
5050 cltv_expiry_delta: (5 << 4) | 0,
5051 htlc_minimum_msat: 0,
5052 htlc_maximum_msat: MAX_VALUE_MSAT,
5054 fee_proportional_millionths: 0,
5055 excess_data: Vec::new()
5057 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
5059 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
5060 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5061 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5062 short_channel_id: 4,
5065 cltv_expiry_delta: (4 << 4) | 0,
5066 htlc_minimum_msat: 0,
5067 htlc_maximum_msat: MAX_VALUE_MSAT,
5069 fee_proportional_millionths: 0,
5070 excess_data: Vec::new()
5072 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
5074 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
5075 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5076 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5077 short_channel_id: 3,
5080 cltv_expiry_delta: (3 << 4) | 0,
5081 htlc_minimum_msat: 0,
5082 htlc_maximum_msat: MAX_VALUE_MSAT,
5084 fee_proportional_millionths: 0,
5085 excess_data: Vec::new()
5087 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
5089 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
5090 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5091 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5092 short_channel_id: 2,
5095 cltv_expiry_delta: (2 << 4) | 0,
5096 htlc_minimum_msat: 0,
5097 htlc_maximum_msat: MAX_VALUE_MSAT,
5099 fee_proportional_millionths: 0,
5100 excess_data: Vec::new()
5103 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
5104 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5105 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5106 short_channel_id: 1,
5109 cltv_expiry_delta: (1 << 4) | 0,
5110 htlc_minimum_msat: 100,
5111 htlc_maximum_msat: MAX_VALUE_MSAT,
5113 fee_proportional_millionths: 0,
5114 excess_data: Vec::new()
5116 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
5119 // Now ensure the route flows simply over nodes 1 and 4 to 6.
5120 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5121 assert_eq!(route.paths.len(), 1);
5122 assert_eq!(route.paths[0].hops.len(), 3);
5124 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
5125 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5126 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
5127 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (5 << 4) | 0);
5128 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(1));
5129 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(6));
5131 assert_eq!(route.paths[0].hops[1].pubkey, nodes[4]);
5132 assert_eq!(route.paths[0].hops[1].short_channel_id, 5);
5133 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
5134 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (1 << 4) | 0);
5135 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(4));
5136 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(5));
5138 assert_eq!(route.paths[0].hops[2].pubkey, nodes[6]);
5139 assert_eq!(route.paths[0].hops[2].short_channel_id, 1);
5140 assert_eq!(route.paths[0].hops[2].fee_msat, 10_000);
5141 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
5142 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
5143 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(1));
5149 fn exact_fee_liquidity_limit() {
5150 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5151 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5152 // we calculated fees on a higher value, resulting in us ignoring such paths.
5153 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5154 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5155 let scorer = ln_test_utils::TestScorer::new();
5156 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5157 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5158 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
5160 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5162 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5163 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5164 short_channel_id: 2,
5167 cltv_expiry_delta: 0,
5168 htlc_minimum_msat: 0,
5169 htlc_maximum_msat: 85_000,
5171 fee_proportional_millionths: 0,
5172 excess_data: Vec::new()
5175 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5176 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5177 short_channel_id: 12,
5180 cltv_expiry_delta: (4 << 4) | 1,
5181 htlc_minimum_msat: 0,
5182 htlc_maximum_msat: 270_000,
5184 fee_proportional_millionths: 1000000,
5185 excess_data: Vec::new()
5189 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5190 // 200% fee charged channel 13 in the 1-to-2 direction.
5191 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5192 assert_eq!(route.paths.len(), 1);
5193 assert_eq!(route.paths[0].hops.len(), 2);
5195 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5196 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5197 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5198 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5199 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5200 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5202 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5203 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5204 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5205 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5206 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
5207 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5212 fn htlc_max_reduction_below_min() {
5213 // Test that if, while walking the graph, we reduce the value being sent to meet an
5214 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5215 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5216 // resulting in us thinking there is no possible path, even if other paths exist.
5217 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5218 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5219 let scorer = ln_test_utils::TestScorer::new();
5220 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5221 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5222 let config = UserConfig::default();
5223 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5225 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5226 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5227 // then try to send 90_000.
5228 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5229 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5230 short_channel_id: 2,
5233 cltv_expiry_delta: 0,
5234 htlc_minimum_msat: 0,
5235 htlc_maximum_msat: 80_000,
5237 fee_proportional_millionths: 0,
5238 excess_data: Vec::new()
5240 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5241 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5242 short_channel_id: 4,
5245 cltv_expiry_delta: (4 << 4) | 1,
5246 htlc_minimum_msat: 90_000,
5247 htlc_maximum_msat: MAX_VALUE_MSAT,
5249 fee_proportional_millionths: 0,
5250 excess_data: Vec::new()
5254 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5255 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5256 // expensive) channels 12-13 path.
5257 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5258 assert_eq!(route.paths.len(), 1);
5259 assert_eq!(route.paths[0].hops.len(), 2);
5261 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5262 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5263 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5264 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5265 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5266 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5268 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5269 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5270 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5271 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5272 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), channelmanager::provided_invoice_features(&config).le_flags());
5273 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5278 fn multiple_direct_first_hops() {
5279 // Previously we'd only ever considered one first hop path per counterparty.
5280 // However, as we don't restrict users to one channel per peer, we really need to support
5281 // looking at all first hop paths.
5282 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5283 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5284 // route over multiple channels with the same first hop.
5285 let secp_ctx = Secp256k1::new();
5286 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5287 let logger = Arc::new(ln_test_utils::TestLogger::new());
5288 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
5289 let scorer = ln_test_utils::TestScorer::new();
5290 let config = UserConfig::default();
5291 let payment_params = PaymentParameters::from_node_id(nodes[0], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5292 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5293 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5296 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5297 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
5298 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
5299 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5300 assert_eq!(route.paths.len(), 1);
5301 assert_eq!(route.paths[0].hops.len(), 1);
5303 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5304 assert_eq!(route.paths[0].hops[0].short_channel_id, 3);
5305 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5308 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5309 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5310 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5311 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5312 assert_eq!(route.paths.len(), 2);
5313 assert_eq!(route.paths[0].hops.len(), 1);
5314 assert_eq!(route.paths[1].hops.len(), 1);
5316 assert!((route.paths[0].hops[0].short_channel_id == 3 && route.paths[1].hops[0].short_channel_id == 2) ||
5317 (route.paths[0].hops[0].short_channel_id == 2 && route.paths[1].hops[0].short_channel_id == 3));
5319 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5320 assert_eq!(route.paths[0].hops[0].fee_msat, 50_000);
5322 assert_eq!(route.paths[1].hops[0].pubkey, nodes[0]);
5323 assert_eq!(route.paths[1].hops[0].fee_msat, 50_000);
5327 // If we have a bunch of outbound channels to the same node, where most are not
5328 // sufficient to pay the full payment, but one is, we should default to just using the
5329 // one single channel that has sufficient balance, avoiding MPP.
5331 // If we have several options above the 3xpayment value threshold, we should pick the
5332 // smallest of them, avoiding further fragmenting our available outbound balance to
5334 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5335 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5336 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5337 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5338 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
5339 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5340 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5341 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5342 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
5343 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5344 assert_eq!(route.paths.len(), 1);
5345 assert_eq!(route.paths[0].hops.len(), 1);
5347 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5348 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5349 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5354 fn prefers_shorter_route_with_higher_fees() {
5355 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5356 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5357 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5359 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5360 let scorer = ln_test_utils::TestScorer::new();
5361 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5362 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5363 let route = get_route(
5364 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5365 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5367 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5369 assert_eq!(route.get_total_fees(), 100);
5370 assert_eq!(route.get_total_amount(), 100);
5371 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5373 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5374 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5375 let scorer = FixedPenaltyScorer::with_penalty(100);
5376 let route = get_route(
5377 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5378 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5380 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5382 assert_eq!(route.get_total_fees(), 300);
5383 assert_eq!(route.get_total_amount(), 100);
5384 assert_eq!(path, vec![2, 4, 7, 10]);
5387 struct BadChannelScorer {
5388 short_channel_id: u64,
5392 impl Writeable for BadChannelScorer {
5393 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5395 impl Score for BadChannelScorer {
5396 type ScoreParams = ();
5397 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5398 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5401 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5402 fn payment_path_successful(&mut self, _path: &Path) {}
5403 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5404 fn probe_successful(&mut self, _path: &Path) {}
5407 struct BadNodeScorer {
5412 impl Writeable for BadNodeScorer {
5413 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5416 impl Score for BadNodeScorer {
5417 type ScoreParams = ();
5418 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5419 if *target == self.node_id { u64::max_value() } else { 0 }
5422 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5423 fn payment_path_successful(&mut self, _path: &Path) {}
5424 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5425 fn probe_successful(&mut self, _path: &Path) {}
5429 fn avoids_routing_through_bad_channels_and_nodes() {
5430 let (secp_ctx, network, _, _, logger) = build_graph();
5431 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5432 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5433 let network_graph = network.read_only();
5435 // A path to nodes[6] exists when no penalties are applied to any channel.
5436 let scorer = ln_test_utils::TestScorer::new();
5437 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5438 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5439 let route = get_route(
5440 &our_id, &payment_params, &network_graph, None, 100,
5441 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5443 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5445 assert_eq!(route.get_total_fees(), 100);
5446 assert_eq!(route.get_total_amount(), 100);
5447 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5449 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5450 let scorer = BadChannelScorer { short_channel_id: 6 };
5451 let route = get_route(
5452 &our_id, &payment_params, &network_graph, None, 100,
5453 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5455 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5457 assert_eq!(route.get_total_fees(), 300);
5458 assert_eq!(route.get_total_amount(), 100);
5459 assert_eq!(path, vec![2, 4, 7, 10]);
5461 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5462 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5464 &our_id, &payment_params, &network_graph, None, 100,
5465 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5467 Err(LightningError { err, .. } ) => {
5468 assert_eq!(err, "Failed to find a path to the given destination");
5470 Ok(_) => panic!("Expected error"),
5475 fn total_fees_single_path() {
5477 paths: vec![Path { hops: vec![
5479 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5480 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5481 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5484 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5485 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5486 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5489 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5490 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5491 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5493 ], blinded_tail: None }],
5494 payment_params: None,
5497 assert_eq!(route.get_total_fees(), 250);
5498 assert_eq!(route.get_total_amount(), 225);
5502 fn total_fees_multi_path() {
5504 paths: vec![Path { hops: vec![
5506 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5507 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5508 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5511 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5512 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5513 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5515 ], blinded_tail: None }, Path { hops: vec![
5517 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5518 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5519 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5522 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5523 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5524 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5526 ], blinded_tail: None }],
5527 payment_params: None,
5530 assert_eq!(route.get_total_fees(), 200);
5531 assert_eq!(route.get_total_amount(), 300);
5535 fn total_empty_route_no_panic() {
5536 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5537 // would both panic if the route was completely empty. We test to ensure they return 0
5538 // here, even though its somewhat nonsensical as a route.
5539 let route = Route { paths: Vec::new(), payment_params: None };
5541 assert_eq!(route.get_total_fees(), 0);
5542 assert_eq!(route.get_total_amount(), 0);
5546 fn limits_total_cltv_delta() {
5547 let (secp_ctx, network, _, _, logger) = build_graph();
5548 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5549 let network_graph = network.read_only();
5551 let scorer = ln_test_utils::TestScorer::new();
5553 // Make sure that generally there is at least one route available
5554 let feasible_max_total_cltv_delta = 1008;
5555 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5556 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5557 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5558 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5559 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5560 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5561 assert_ne!(path.len(), 0);
5563 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5564 let fail_max_total_cltv_delta = 23;
5565 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5566 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5567 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5569 Err(LightningError { err, .. } ) => {
5570 assert_eq!(err, "Failed to find a path to the given destination");
5572 Ok(_) => panic!("Expected error"),
5577 fn avoids_recently_failed_paths() {
5578 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
5579 // randomly inserting channels into it until we can't find a route anymore.
5580 let (secp_ctx, network, _, _, logger) = build_graph();
5581 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5582 let network_graph = network.read_only();
5584 let scorer = ln_test_utils::TestScorer::new();
5585 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5586 .with_max_path_count(1);
5587 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5588 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5590 // We should be able to find a route initially, and then after we fail a few random
5591 // channels eventually we won't be able to any longer.
5592 assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).is_ok());
5594 if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
5595 for chan in route.paths[0].hops.iter() {
5596 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
5598 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
5599 % route.paths[0].hops.len();
5600 payment_params.previously_failed_channels.push(route.paths[0].hops[victim].short_channel_id);
5606 fn limits_path_length() {
5607 let (secp_ctx, network, _, _, logger) = build_line_graph();
5608 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5609 let network_graph = network.read_only();
5611 let scorer = ln_test_utils::TestScorer::new();
5612 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5613 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5615 // First check we can actually create a long route on this graph.
5616 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
5617 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100,
5618 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5619 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5620 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5622 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5623 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
5624 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100,
5625 Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5627 Err(LightningError { err, .. } ) => {
5628 assert_eq!(err, "Failed to find a path to the given destination");
5630 Ok(_) => panic!("Expected error"),
5635 fn adds_and_limits_cltv_offset() {
5636 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5637 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5639 let scorer = ln_test_utils::TestScorer::new();
5641 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5642 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5643 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5644 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5645 assert_eq!(route.paths.len(), 1);
5647 let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5649 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5650 let mut route_default = route.clone();
5651 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5652 let cltv_expiry_deltas_default = route_default.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5653 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5654 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5655 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5657 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5658 let mut route_limited = route.clone();
5659 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5660 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5661 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5662 let cltv_expiry_deltas_limited = route_limited.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5663 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5667 fn adds_plausible_cltv_offset() {
5668 let (secp_ctx, network, _, _, logger) = build_graph();
5669 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5670 let network_graph = network.read_only();
5671 let network_nodes = network_graph.nodes();
5672 let network_channels = network_graph.channels();
5673 let scorer = ln_test_utils::TestScorer::new();
5674 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5675 let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5676 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5678 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100,
5679 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5680 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5682 let mut path_plausibility = vec![];
5684 for p in route.paths {
5685 // 1. Select random observation point
5686 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5687 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5689 prng.process_in_place(&mut random_bytes);
5690 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.hops.len());
5691 let observation_point = NodeId::from_pubkey(&p.hops.get(random_path_index).unwrap().pubkey);
5693 // 2. Calculate what CLTV expiry delta we would observe there
5694 let observed_cltv_expiry_delta: u32 = p.hops[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5696 // 3. Starting from the observation point, find candidate paths
5697 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5698 candidates.push_back((observation_point, vec![]));
5700 let mut found_plausible_candidate = false;
5702 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5703 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5704 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5705 found_plausible_candidate = true;
5706 break 'candidate_loop;
5710 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5711 for channel_id in &cur_node.channels {
5712 if let Some(channel_info) = network_channels.get(&channel_id) {
5713 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5714 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
5715 if cur_path_cltv_deltas.iter().sum::<u32>()
5716 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5717 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5718 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5719 candidates.push_back((*next_id, new_path_cltv_deltas));
5727 path_plausibility.push(found_plausible_candidate);
5729 assert!(path_plausibility.iter().all(|x| *x));
5733 fn builds_correct_path_from_hops() {
5734 let (secp_ctx, network, _, _, logger) = build_graph();
5735 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5736 let network_graph = network.read_only();
5738 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5739 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5741 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5742 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5743 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5744 &network_graph, 100, Arc::clone(&logger), &random_seed_bytes).unwrap();
5745 let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5746 assert_eq!(hops.len(), route.paths[0].hops.len());
5747 for (idx, hop_pubkey) in hops.iter().enumerate() {
5748 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5753 fn avoids_saturating_channels() {
5754 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5755 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5756 let decay_params = ProbabilisticScoringDecayParameters::default();
5757 let scorer = ProbabilisticScorer::new(decay_params, &*network_graph, Arc::clone(&logger));
5759 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
5760 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
5761 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5762 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5763 short_channel_id: 4,
5766 cltv_expiry_delta: (4 << 4) | 1,
5767 htlc_minimum_msat: 0,
5768 htlc_maximum_msat: 250_000_000,
5770 fee_proportional_millionths: 0,
5771 excess_data: Vec::new()
5773 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5774 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5775 short_channel_id: 13,
5778 cltv_expiry_delta: (13 << 4) | 1,
5779 htlc_minimum_msat: 0,
5780 htlc_maximum_msat: 250_000_000,
5782 fee_proportional_millionths: 0,
5783 excess_data: Vec::new()
5786 let config = UserConfig::default();
5787 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5788 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5789 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5790 // 100,000 sats is less than the available liquidity on each channel, set above.
5791 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();
5792 assert_eq!(route.paths.len(), 2);
5793 assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
5794 (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
5797 #[cfg(not(feature = "no-std"))]
5798 pub(super) fn random_init_seed() -> u64 {
5799 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5800 use core::hash::{BuildHasher, Hasher};
5801 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5802 println!("Using seed of {}", seed);
5805 #[cfg(not(feature = "no-std"))]
5806 use crate::util::ser::ReadableArgs;
5809 #[cfg(not(feature = "no-std"))]
5810 fn generate_routes() {
5811 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
5813 let mut d = match super::bench_utils::get_route_file() {
5820 let logger = ln_test_utils::TestLogger::new();
5821 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5822 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5823 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5825 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5826 let mut seed = random_init_seed() as usize;
5827 let nodes = graph.read_only().nodes().clone();
5828 'load_endpoints: for _ in 0..10 {
5830 seed = seed.overflowing_mul(0xdeadbeef).0;
5831 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5832 seed = seed.overflowing_mul(0xdeadbeef).0;
5833 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5834 let payment_params = PaymentParameters::from_node_id(dst, 42);
5835 let amt = seed as u64 % 200_000_000;
5836 let params = ProbabilisticScoringFeeParameters::default();
5837 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
5838 if get_route(src, &payment_params, &graph.read_only(), None, amt, &logger, &scorer, ¶ms, &random_seed_bytes).is_ok() {
5839 continue 'load_endpoints;
5846 #[cfg(not(feature = "no-std"))]
5847 fn generate_routes_mpp() {
5848 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
5850 let mut d = match super::bench_utils::get_route_file() {
5857 let logger = ln_test_utils::TestLogger::new();
5858 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5859 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5860 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5861 let config = UserConfig::default();
5863 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5864 let mut seed = random_init_seed() as usize;
5865 let nodes = graph.read_only().nodes().clone();
5866 'load_endpoints: for _ in 0..10 {
5868 seed = seed.overflowing_mul(0xdeadbeef).0;
5869 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5870 seed = seed.overflowing_mul(0xdeadbeef).0;
5871 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5872 let payment_params = PaymentParameters::from_node_id(dst, 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5873 let amt = seed as u64 % 200_000_000;
5874 let params = ProbabilisticScoringFeeParameters::default();
5875 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
5876 if get_route(src, &payment_params, &graph.read_only(), None, amt, &logger, &scorer, ¶ms, &random_seed_bytes).is_ok() {
5877 continue 'load_endpoints;
5884 fn honors_manual_penalties() {
5885 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
5886 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5888 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5889 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5891 let mut scorer_params = ProbabilisticScoringFeeParameters::default();
5892 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), Arc::clone(&network_graph), Arc::clone(&logger));
5894 // First check set manual penalties are returned by the scorer.
5895 let usage = ChannelUsage {
5897 inflight_htlc_msat: 0,
5898 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
5900 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
5901 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
5902 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage, &scorer_params), 456);
5904 // Then check we can get a normal route
5905 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
5906 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5907 assert!(route.is_ok());
5909 // Then check that we can't get a route if we ban an intermediate node.
5910 scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3]));
5911 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5912 assert!(route.is_err());
5914 // Finally make sure we can route again, when we remove the ban.
5915 scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3]));
5916 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
5917 assert!(route.is_ok());
5921 fn abide_by_route_hint_max_htlc() {
5922 // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
5923 // params in the final route.
5924 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5925 let netgraph = network_graph.read_only();
5926 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5927 let scorer = ln_test_utils::TestScorer::new();
5928 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5929 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5930 let config = UserConfig::default();
5932 let max_htlc_msat = 50_000;
5933 let route_hint_1 = RouteHint(vec![RouteHintHop {
5934 src_node_id: nodes[2],
5935 short_channel_id: 42,
5938 proportional_millionths: 0,
5940 cltv_expiry_delta: 10,
5941 htlc_minimum_msat: None,
5942 htlc_maximum_msat: Some(max_htlc_msat),
5944 let dest_node_id = ln_test_utils::pubkey(42);
5945 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
5946 .with_route_hints(vec![route_hint_1.clone()]).unwrap()
5947 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5949 // Make sure we'll error if our route hints don't have enough liquidity according to their
5950 // htlc_maximum_msat.
5951 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
5952 &payment_params, &netgraph, None, max_htlc_msat + 1, Arc::clone(&logger), &scorer, &(),
5955 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5956 } else { panic!(); }
5958 // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
5959 let mut route_hint_2 = route_hint_1.clone();
5960 route_hint_2.0[0].short_channel_id = 43;
5961 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
5962 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
5963 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5964 let route = get_route(&our_id, &payment_params, &netgraph, None, max_htlc_msat + 1,
5965 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5966 assert_eq!(route.paths.len(), 2);
5967 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
5968 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
5972 fn direct_channel_to_hints_with_max_htlc() {
5973 // Check that if we have a first hop channel peer that's connected to multiple provided route
5974 // hints, that we properly split the payment between the route hints if needed.
5975 let logger = Arc::new(ln_test_utils::TestLogger::new());
5976 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
5977 let scorer = ln_test_utils::TestScorer::new();
5978 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5979 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5980 let config = UserConfig::default();
5982 let our_node_id = ln_test_utils::pubkey(42);
5983 let intermed_node_id = ln_test_utils::pubkey(43);
5984 let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
5986 let amt_msat = 900_000;
5987 let max_htlc_msat = 500_000;
5988 let route_hint_1 = RouteHint(vec![RouteHintHop {
5989 src_node_id: intermed_node_id,
5990 short_channel_id: 44,
5993 proportional_millionths: 0,
5995 cltv_expiry_delta: 10,
5996 htlc_minimum_msat: None,
5997 htlc_maximum_msat: Some(max_htlc_msat),
5999 src_node_id: intermed_node_id,
6000 short_channel_id: 45,
6003 proportional_millionths: 0,
6005 cltv_expiry_delta: 10,
6006 htlc_minimum_msat: None,
6007 // Check that later route hint max htlcs don't override earlier ones
6008 htlc_maximum_msat: Some(max_htlc_msat - 50),
6010 let mut route_hint_2 = route_hint_1.clone();
6011 route_hint_2.0[0].short_channel_id = 46;
6012 route_hint_2.0[1].short_channel_id = 47;
6013 let dest_node_id = ln_test_utils::pubkey(44);
6014 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
6015 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
6016 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6018 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6019 Some(&first_hop.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6020 &random_seed_bytes).unwrap();
6021 assert_eq!(route.paths.len(), 2);
6022 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6023 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6024 assert_eq!(route.get_total_amount(), amt_msat);
6026 // Re-run but with two first hop channels connected to the same route hint peers that must be
6028 let first_hops = vec![
6029 get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6030 get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6032 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6033 Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6034 &random_seed_bytes).unwrap();
6035 // TODO: `get_route` returns a suboptimal route here because first hop channels are not
6036 // resorted on the fly when processing route hints.
6037 assert_eq!(route.paths.len(), 3);
6038 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6039 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6040 assert!(route.paths[2].hops.last().unwrap().fee_msat <= max_htlc_msat);
6041 assert_eq!(route.get_total_amount(), amt_msat);
6045 fn blinded_route_ser() {
6046 let blinded_path_1 = BlindedPath {
6047 introduction_node_id: ln_test_utils::pubkey(42),
6048 blinding_point: ln_test_utils::pubkey(43),
6050 BlindedHop { blinded_node_id: ln_test_utils::pubkey(44), encrypted_payload: Vec::new() },
6051 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() }
6054 let blinded_path_2 = BlindedPath {
6055 introduction_node_id: ln_test_utils::pubkey(46),
6056 blinding_point: ln_test_utils::pubkey(47),
6058 BlindedHop { blinded_node_id: ln_test_utils::pubkey(48), encrypted_payload: Vec::new() },
6059 BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }
6062 // (De)serialize a Route with 1 blinded path out of two total paths.
6063 let mut route = Route { paths: vec![Path {
6064 hops: vec![RouteHop {
6065 pubkey: ln_test_utils::pubkey(50),
6066 node_features: NodeFeatures::empty(),
6067 short_channel_id: 42,
6068 channel_features: ChannelFeatures::empty(),
6070 cltv_expiry_delta: 0,
6072 blinded_tail: Some(BlindedTail {
6073 hops: blinded_path_1.blinded_hops,
6074 blinding_point: blinded_path_1.blinding_point,
6075 excess_final_cltv_expiry_delta: 40,
6076 final_value_msat: 100,
6078 hops: vec![RouteHop {
6079 pubkey: ln_test_utils::pubkey(51),
6080 node_features: NodeFeatures::empty(),
6081 short_channel_id: 43,
6082 channel_features: ChannelFeatures::empty(),
6084 cltv_expiry_delta: 0,
6085 }], blinded_tail: None }],
6086 payment_params: None,
6088 let encoded_route = route.encode();
6089 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6090 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6091 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6093 // (De)serialize a Route with two paths, each containing a blinded tail.
6094 route.paths[1].blinded_tail = Some(BlindedTail {
6095 hops: blinded_path_2.blinded_hops,
6096 blinding_point: blinded_path_2.blinding_point,
6097 excess_final_cltv_expiry_delta: 41,
6098 final_value_msat: 101,
6100 let encoded_route = route.encode();
6101 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6102 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6103 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6107 fn blinded_path_inflight_processing() {
6108 // Ensure we'll score the channel that's inbound to a blinded path's introduction node, and
6109 // account for the blinded tail's final amount_msat.
6110 let mut inflight_htlcs = InFlightHtlcs::new();
6111 let blinded_path = BlindedPath {
6112 introduction_node_id: ln_test_utils::pubkey(43),
6113 blinding_point: ln_test_utils::pubkey(48),
6114 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }],
6117 hops: vec![RouteHop {
6118 pubkey: ln_test_utils::pubkey(42),
6119 node_features: NodeFeatures::empty(),
6120 short_channel_id: 42,
6121 channel_features: ChannelFeatures::empty(),
6123 cltv_expiry_delta: 0,
6126 pubkey: blinded_path.introduction_node_id,
6127 node_features: NodeFeatures::empty(),
6128 short_channel_id: 43,
6129 channel_features: ChannelFeatures::empty(),
6131 cltv_expiry_delta: 0,
6133 blinded_tail: Some(BlindedTail {
6134 hops: blinded_path.blinded_hops,
6135 blinding_point: blinded_path.blinding_point,
6136 excess_final_cltv_expiry_delta: 0,
6137 final_value_msat: 200,
6140 inflight_htlcs.process_path(&path, ln_test_utils::pubkey(44));
6141 assert_eq!(*inflight_htlcs.0.get(&(42, true)).unwrap(), 301);
6142 assert_eq!(*inflight_htlcs.0.get(&(43, false)).unwrap(), 201);
6146 fn blinded_path_cltv_shadow_offset() {
6147 // Make sure we add a shadow offset when sending to blinded paths.
6148 let blinded_path = BlindedPath {
6149 introduction_node_id: ln_test_utils::pubkey(43),
6150 blinding_point: ln_test_utils::pubkey(44),
6152 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() },
6153 BlindedHop { blinded_node_id: ln_test_utils::pubkey(46), encrypted_payload: Vec::new() }
6156 let mut route = Route { paths: vec![Path {
6157 hops: vec![RouteHop {
6158 pubkey: ln_test_utils::pubkey(42),
6159 node_features: NodeFeatures::empty(),
6160 short_channel_id: 42,
6161 channel_features: ChannelFeatures::empty(),
6163 cltv_expiry_delta: 0,
6166 pubkey: blinded_path.introduction_node_id,
6167 node_features: NodeFeatures::empty(),
6168 short_channel_id: 43,
6169 channel_features: ChannelFeatures::empty(),
6171 cltv_expiry_delta: 0,
6174 blinded_tail: Some(BlindedTail {
6175 hops: blinded_path.blinded_hops,
6176 blinding_point: blinded_path.blinding_point,
6177 excess_final_cltv_expiry_delta: 0,
6178 final_value_msat: 200,
6180 }], payment_params: None};
6182 let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
6183 let (_, network_graph, _, _, _) = build_line_graph();
6184 add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
6185 assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
6186 assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
6190 #[cfg(all(test, not(feature = "no-std")))]
6191 pub(crate) mod bench_utils {
6193 /// Tries to open a network graph file, or panics with a URL to fetch it.
6194 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
6195 let res = File::open("net_graph-2023-01-18.bin") // By default we're run in RL/lightning
6196 .or_else(|_| File::open("lightning/net_graph-2023-01-18.bin")) // We may be run manually in RL/
6197 .or_else(|_| { // Fall back to guessing based on the binary location
6198 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
6199 let mut path = std::env::current_exe().unwrap();
6200 path.pop(); // lightning-...
6202 path.pop(); // debug
6203 path.pop(); // target
6204 path.push("lightning");
6205 path.push("net_graph-2023-01-18.bin");
6206 eprintln!("{}", path.to_str().unwrap());
6209 .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");
6210 #[cfg(require_route_graph_test)]
6211 return Ok(res.unwrap());
6212 #[cfg(not(require_route_graph_test))]
6217 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
6220 use bitcoin::hashes::Hash;
6221 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
6222 use crate::chain::transaction::OutPoint;
6223 use crate::sign::{EntropySource, KeysManager};
6224 use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
6225 use crate::ln::features::InvoiceFeatures;
6226 use crate::routing::gossip::NetworkGraph;
6227 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
6228 use crate::util::config::UserConfig;
6229 use crate::util::logger::{Logger, Record};
6230 use crate::util::ser::ReadableArgs;
6234 struct DummyLogger {}
6235 impl Logger for DummyLogger {
6236 fn log(&self, _record: &Record) {}
6239 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
6240 let mut d = bench_utils::get_route_file().unwrap();
6241 NetworkGraph::read(&mut d, logger).unwrap()
6244 fn payer_pubkey() -> PublicKey {
6245 let secp_ctx = Secp256k1::new();
6246 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
6250 fn first_hop(node_id: PublicKey) -> ChannelDetails {
6252 channel_id: [0; 32],
6253 counterparty: ChannelCounterparty {
6254 features: channelmanager::provided_init_features(&UserConfig::default()),
6256 unspendable_punishment_reserve: 0,
6257 forwarding_info: None,
6258 outbound_htlc_minimum_msat: None,
6259 outbound_htlc_maximum_msat: None,
6261 funding_txo: Some(OutPoint {
6262 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
6265 short_channel_id: Some(1),
6266 inbound_scid_alias: None,
6267 outbound_scid_alias: None,
6268 channel_value_satoshis: 10_000_000,
6270 balance_msat: 10_000_000,
6271 outbound_capacity_msat: 10_000_000,
6272 next_outbound_htlc_limit_msat: 10_000_000,
6273 inbound_capacity_msat: 0,
6274 unspendable_punishment_reserve: None,
6275 confirmations_required: None,
6276 confirmations: None,
6277 force_close_spend_delay: None,
6279 is_channel_ready: true,
6282 inbound_htlc_minimum_msat: None,
6283 inbound_htlc_maximum_msat: None,
6285 feerate_sat_per_1000_weight: None,
6290 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
6291 let logger = DummyLogger {};
6292 let network_graph = read_network_graph(&logger);
6293 let scorer = FixedPenaltyScorer::with_penalty(0);
6294 generate_routes(bench, &network_graph, scorer, &(), InvoiceFeatures::empty());
6298 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
6299 let logger = DummyLogger {};
6300 let network_graph = read_network_graph(&logger);
6301 let scorer = FixedPenaltyScorer::with_penalty(0);
6302 generate_routes(bench, &network_graph, scorer, &(), channelmanager::provided_invoice_features(&UserConfig::default()));
6306 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
6307 let logger = DummyLogger {};
6308 let network_graph = read_network_graph(&logger);
6309 let params = ProbabilisticScoringFeeParameters::default();
6310 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6311 generate_routes(bench, &network_graph, scorer, ¶ms, InvoiceFeatures::empty());
6315 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
6316 let logger = DummyLogger {};
6317 let network_graph = read_network_graph(&logger);
6318 let params = ProbabilisticScoringFeeParameters::default();
6319 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6320 generate_routes(bench, &network_graph, scorer, ¶ms, channelmanager::provided_invoice_features(&UserConfig::default()));
6323 fn generate_routes<S: Score>(
6324 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S, score_params: &S::ScoreParams,
6325 features: InvoiceFeatures
6327 let nodes = graph.read_only().nodes().clone();
6328 let payer = payer_pubkey();
6329 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6330 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6332 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
6333 let mut routes = Vec::new();
6334 let mut route_endpoints = Vec::new();
6335 let mut seed: usize = 0xdeadbeef;
6336 'load_endpoints: for _ in 0..150 {
6339 let src = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
6341 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
6342 let params = PaymentParameters::from_node_id(dst, 42).with_bolt11_features(features.clone()).unwrap();
6343 let first_hop = first_hop(src);
6344 let amt = seed as u64 % 1_000_000;
6345 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, &DummyLogger{}, &scorer, score_params, &random_seed_bytes) {
6347 route_endpoints.push((first_hop, params, amt));
6348 continue 'load_endpoints;
6353 // ...and seed the scorer with success and failure data...
6354 for route in routes {
6355 let amount = route.get_total_amount();
6356 if amount < 250_000 {
6357 for path in route.paths {
6358 scorer.payment_path_successful(&path);
6360 } else if amount > 750_000 {
6361 for path in route.paths {
6362 let short_channel_id = path.hops[path.hops.len() / 2].short_channel_id;
6363 scorer.payment_path_failed(&path, short_channel_id);
6368 // Because we've changed channel scores, its possible we'll take different routes to the
6369 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
6370 // requires a too-high CLTV delta.
6371 route_endpoints.retain(|(first_hop, params, amt)| {
6372 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok()
6374 route_endpoints.truncate(100);
6375 assert_eq!(route_endpoints.len(), 100);
6377 // ...then benchmark finding paths between the nodes we learned.
6380 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
6381 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok());