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::{Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures};
20 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
21 use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice};
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};
31 use alloc::collections::BinaryHeap;
33 use core::ops::{Deref, DerefMut};
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, Score = 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, Score = 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, Score = 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().deref_mut(), &inflight_htlcs),
83 /// A trait defining behavior for routing a payment.
85 /// Finds a [`Route`] for a payment between the given `payer` and a payee.
87 /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
88 /// and [`RouteParameters::final_value_msat`], respectively.
90 &self, payer: &PublicKey, route_params: &RouteParameters,
91 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
92 ) -> Result<Route, LightningError>;
93 /// Finds a [`Route`] for a payment between the given `payer` and a payee.
95 /// The `payee` and the payment's value are given in [`RouteParameters::payment_params`]
96 /// and [`RouteParameters::final_value_msat`], respectively.
98 /// Includes a [`PaymentHash`] and a [`PaymentId`] to be able to correlate the request with a specific
100 fn find_route_with_id(
101 &self, payer: &PublicKey, route_params: &RouteParameters,
102 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs,
103 _payment_hash: PaymentHash, _payment_id: PaymentId
104 ) -> Result<Route, LightningError> {
105 self.find_route(payer, route_params, first_hops, inflight_htlcs)
109 /// [`Score`] implementation that factors in in-flight HTLC liquidity.
111 /// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
114 /// [`Score`]: crate::routing::scoring::Score
115 pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score<ScoreParams = SP>, SP: Sized> {
117 // Maps a channel's short channel id and its direction to the liquidity used up.
118 inflight_htlcs: &'a InFlightHtlcs,
121 impl<'a, S: Score<ScoreParams = SP>, SP: Sized> ScorerAccountingForInFlightHtlcs<'a, S, SP> {
122 /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
123 pub fn new(scorer: &'a mut S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
124 ScorerAccountingForInFlightHtlcs {
132 impl<'a, S: Score<ScoreParams = SP>, SP: Sized> Writeable for ScorerAccountingForInFlightHtlcs<'a, S, SP> {
133 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
136 impl<'a, S: Score<ScoreParams = SP>, SP: Sized> Score for ScorerAccountingForInFlightHtlcs<'a, S, SP> {
137 type ScoreParams = S::ScoreParams;
138 fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage, score_params: &Self::ScoreParams) -> u64 {
139 if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
140 source, target, short_channel_id
142 let usage = ChannelUsage {
143 inflight_htlc_msat: usage.inflight_htlc_msat + used_liquidity,
147 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
149 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage, score_params)
153 fn payment_path_failed(&mut self, path: &Path, short_channel_id: u64) {
154 self.scorer.payment_path_failed(path, short_channel_id)
157 fn payment_path_successful(&mut self, path: &Path) {
158 self.scorer.payment_path_successful(path)
161 fn probe_failed(&mut self, path: &Path, short_channel_id: u64) {
162 self.scorer.probe_failed(path, short_channel_id)
165 fn probe_successful(&mut self, path: &Path) {
166 self.scorer.probe_successful(path)
170 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
171 /// in-use channel liquidity.
173 pub struct InFlightHtlcs(
174 // A map with liquidity value (in msat) keyed by a short channel id and the direction the HTLC
175 // is traveling in. The direction boolean is determined by checking if the HTLC source's public
176 // key is less than its destination. See `InFlightHtlcs::used_liquidity_msat` for more
178 HashMap<(u64, bool), u64>
182 /// Constructs an empty `InFlightHtlcs`.
183 pub fn new() -> Self { InFlightHtlcs(HashMap::new()) }
185 /// Takes in a path with payer's node id and adds the path's details to `InFlightHtlcs`.
186 pub fn process_path(&mut self, path: &Path, payer_node_id: PublicKey) {
187 if path.hops.is_empty() { return };
189 let mut cumulative_msat = 0;
190 if let Some(tail) = &path.blinded_tail {
191 cumulative_msat += tail.final_value_msat;
194 // total_inflight_map needs to be direction-sensitive when keeping track of the HTLC value
195 // that is held up. However, the `hops` array, which is a path returned by `find_route` in
196 // the router excludes the payer node. In the following lines, the payer's information is
197 // hardcoded with an inflight value of 0 so that we can correctly represent the first hop
198 // in our sliding window of two.
199 let reversed_hops_with_payer = path.hops.iter().rev().skip(1)
200 .map(|hop| hop.pubkey)
201 .chain(core::iter::once(payer_node_id));
203 // Taking the reversed vector from above, we zip it with just the reversed hops list to
204 // work "backwards" of the given path, since the last hop's `fee_msat` actually represents
205 // the total amount sent.
206 for (next_hop, prev_hop) in path.hops.iter().rev().zip(reversed_hops_with_payer) {
207 cumulative_msat += next_hop.fee_msat;
209 .entry((next_hop.short_channel_id, NodeId::from_pubkey(&prev_hop) < NodeId::from_pubkey(&next_hop.pubkey)))
210 .and_modify(|used_liquidity_msat| *used_liquidity_msat += cumulative_msat)
211 .or_insert(cumulative_msat);
215 /// Adds a known HTLC given the public key of the HTLC source, target, and short channel
217 pub fn add_inflight_htlc(&mut self, source: &NodeId, target: &NodeId, channel_scid: u64, used_msat: u64){
219 .entry((channel_scid, source < target))
220 .and_modify(|used_liquidity_msat| *used_liquidity_msat += used_msat)
221 .or_insert(used_msat);
224 /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
226 pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
227 self.0.get(&(channel_scid, source < target)).map(|v| *v)
231 impl Writeable for InFlightHtlcs {
232 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
235 impl Readable for InFlightHtlcs {
236 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
237 let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
238 Ok(Self(infight_map))
242 /// A hop in a route, and additional metadata about it. "Hop" is defined as a node and the channel
243 /// that leads to it.
244 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
245 pub struct RouteHop {
246 /// The node_id of the node at this hop.
247 pub pubkey: PublicKey,
248 /// The node_announcement features of the node at this hop. For the last hop, these may be
249 /// amended to match the features present in the invoice this node generated.
250 pub node_features: NodeFeatures,
251 /// The channel that should be used from the previous hop to reach this node.
252 pub short_channel_id: u64,
253 /// The channel_announcement features of the channel that should be used from the previous hop
254 /// to reach this node.
255 pub channel_features: ChannelFeatures,
256 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
257 /// If this is the last hop in [`Path::hops`]:
258 /// * if we're sending to a [`BlindedPath`], this is the fee paid for use of the entire blinded path
259 /// * otherwise, this is the full value of this [`Path`]'s part of the payment
261 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
263 /// The CLTV delta added for this hop.
264 /// If this is the last hop in [`Path::hops`]:
265 /// * if we're sending to a [`BlindedPath`], this is the CLTV delta for the entire blinded path
266 /// * otherwise, this is the CLTV delta expected at the destination
268 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
269 pub cltv_expiry_delta: u32,
272 impl_writeable_tlv_based!(RouteHop, {
273 (0, pubkey, required),
274 (2, node_features, required),
275 (4, short_channel_id, required),
276 (6, channel_features, required),
277 (8, fee_msat, required),
278 (10, cltv_expiry_delta, required),
281 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
282 /// their [`Bolt12Invoice`].
284 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
285 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
286 pub struct BlindedTail {
287 /// The hops of the [`BlindedPath`] provided by the recipient.
289 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
290 pub hops: Vec<BlindedHop>,
291 /// The blinding point of the [`BlindedPath`] provided by the recipient.
293 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
294 pub blinding_point: PublicKey,
295 /// Excess CLTV delta added to the recipient's CLTV expiry to deter intermediate nodes from
296 /// inferring the destination. May be 0.
297 pub excess_final_cltv_expiry_delta: u32,
298 /// The total amount paid on this [`Path`], excluding the fees.
299 pub final_value_msat: u64,
302 impl_writeable_tlv_based!(BlindedTail, {
303 (0, hops, required_vec),
304 (2, blinding_point, required),
305 (4, excess_final_cltv_expiry_delta, required),
306 (6, final_value_msat, required),
309 /// A path in a [`Route`] to the payment recipient. Must always be at least length one.
310 /// If no [`Path::blinded_tail`] is present, then [`Path::hops`] length may be up to 19.
311 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
313 /// The list of unblinded hops in this [`Path`]. Must be at least length one.
314 pub hops: Vec<RouteHop>,
315 /// The blinded path at which this path terminates, if we're sending to one, and its metadata.
316 pub blinded_tail: Option<BlindedTail>,
320 /// Gets the fees for a given path, excluding any excess paid to the recipient.
321 pub fn fee_msat(&self) -> u64 {
322 match &self.blinded_tail {
323 Some(_) => self.hops.iter().map(|hop| hop.fee_msat).sum::<u64>(),
325 // Do not count last hop of each path since that's the full value of the payment
326 self.hops.split_last().map_or(0,
327 |(_, path_prefix)| path_prefix.iter().map(|hop| hop.fee_msat).sum())
332 /// Gets the total amount paid on this [`Path`], excluding the fees.
333 pub fn final_value_msat(&self) -> u64 {
334 match &self.blinded_tail {
335 Some(blinded_tail) => blinded_tail.final_value_msat,
336 None => self.hops.last().map_or(0, |hop| hop.fee_msat)
340 /// Gets the final hop's CLTV expiry delta.
341 pub fn final_cltv_expiry_delta(&self) -> Option<u32> {
342 match &self.blinded_tail {
344 None => self.hops.last().map(|hop| hop.cltv_expiry_delta)
349 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
350 /// it can take multiple paths. Each path is composed of one or more hops through the network.
351 #[derive(Clone, Hash, PartialEq, Eq)]
353 /// The list of [`Path`]s taken for a single (potentially-)multi-part payment. If no
354 /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
356 pub paths: Vec<Path>,
357 /// The `payment_params` parameter passed via [`RouteParameters`] to [`find_route`].
359 /// This is used by `ChannelManager` to track information which may be required for retries.
360 pub payment_params: Option<PaymentParameters>,
364 /// Returns the total amount of fees paid on this [`Route`].
366 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
367 /// the amount passed to [`find_route`]'s `route_params.final_value_msat`.
368 pub fn get_total_fees(&self) -> u64 {
369 self.paths.iter().map(|path| path.fee_msat()).sum()
372 /// Returns the total amount paid on this [`Route`], excluding the fees. Might be more than
373 /// requested if we had to reach htlc_minimum_msat.
374 pub fn get_total_amount(&self) -> u64 {
375 self.paths.iter().map(|path| path.final_value_msat()).sum()
379 const SERIALIZATION_VERSION: u8 = 1;
380 const MIN_SERIALIZATION_VERSION: u8 = 1;
382 impl Writeable for Route {
383 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
384 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
385 (self.paths.len() as u64).write(writer)?;
386 let mut blinded_tails = Vec::new();
387 for path in self.paths.iter() {
388 (path.hops.len() as u8).write(writer)?;
389 for (idx, hop) in path.hops.iter().enumerate() {
391 if let Some(blinded_tail) = &path.blinded_tail {
392 if blinded_tails.is_empty() {
393 blinded_tails = Vec::with_capacity(path.hops.len());
395 blinded_tails.push(None);
398 blinded_tails.push(Some(blinded_tail));
399 } else if !blinded_tails.is_empty() { blinded_tails.push(None); }
402 write_tlv_fields!(writer, {
403 (1, self.payment_params, option),
404 (2, blinded_tails, optional_vec),
410 impl Readable for Route {
411 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
412 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
413 let path_count: u64 = Readable::read(reader)?;
414 if path_count == 0 { return Err(DecodeError::InvalidValue); }
415 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
416 let mut min_final_cltv_expiry_delta = u32::max_value();
417 for _ in 0..path_count {
418 let hop_count: u8 = Readable::read(reader)?;
419 let mut hops: Vec<RouteHop> = Vec::with_capacity(hop_count as usize);
420 for _ in 0..hop_count {
421 hops.push(Readable::read(reader)?);
423 if hops.is_empty() { return Err(DecodeError::InvalidValue); }
424 min_final_cltv_expiry_delta =
425 cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
426 paths.push(Path { hops, blinded_tail: None });
428 _init_and_read_tlv_fields!(reader, {
429 (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
430 (2, blinded_tails, optional_vec),
432 let blinded_tails = blinded_tails.unwrap_or(Vec::new());
433 if blinded_tails.len() != 0 {
434 if blinded_tails.len() != paths.len() { return Err(DecodeError::InvalidValue) }
435 for (path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
436 path.blinded_tail = blinded_tail_opt;
439 Ok(Route { paths, payment_params })
443 /// Parameters needed to find a [`Route`].
445 /// Passed to [`find_route`] and [`build_route_from_hops`].
446 #[derive(Clone, Debug, PartialEq, Eq)]
447 pub struct RouteParameters {
448 /// The parameters of the failed payment path.
449 pub payment_params: PaymentParameters,
451 /// The amount in msats sent on the failed payment path.
452 pub final_value_msat: u64,
455 impl Writeable for RouteParameters {
456 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
457 write_tlv_fields!(writer, {
458 (0, self.payment_params, required),
459 (2, self.final_value_msat, required),
460 // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
461 // `RouteParameters` directly. For compatibility, we write it here.
462 (4, self.payment_params.payee.final_cltv_expiry_delta(), option),
468 impl Readable for RouteParameters {
469 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
470 _init_and_read_tlv_fields!(reader, {
471 (0, payment_params, (required: ReadableArgs, 0)),
472 (2, final_value_msat, required),
473 (4, final_cltv_delta, option),
475 let mut payment_params: PaymentParameters = payment_params.0.unwrap();
476 if let Payee::Clear { ref mut final_cltv_expiry_delta, .. } = payment_params.payee {
477 if final_cltv_expiry_delta == &0 {
478 *final_cltv_expiry_delta = final_cltv_delta.ok_or(DecodeError::InvalidValue)?;
483 final_value_msat: final_value_msat.0.unwrap(),
488 /// Maximum total CTLV difference we allow for a full payment path.
489 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
491 /// Maximum number of paths we allow an (MPP) payment to have.
492 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
493 // limits, but for now more than 10 paths likely carries too much one-path failure.
494 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
496 const DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF: u8 = 2;
498 // The median hop CLTV expiry delta currently seen in the network.
499 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
501 // During routing, we only consider paths shorter than our maximum length estimate.
502 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
503 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
504 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
506 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
507 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
508 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
509 // (payment_secret and total_msat) = 93 bytes for the final hop.
510 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
511 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
512 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
514 /// Information used to route a payment.
515 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
516 pub struct PaymentParameters {
517 /// Information about the payee, such as their features and route hints for their channels.
520 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
521 pub expiry_time: Option<u64>,
523 /// The maximum total CLTV delta we accept for the route.
524 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
525 pub max_total_cltv_expiry_delta: u32,
527 /// The maximum number of paths that may be used by (MPP) payments.
528 /// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
529 pub max_path_count: u8,
531 /// Selects the maximum share of a channel's total capacity which will be sent over a channel,
532 /// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
533 /// a lower value prefers to send larger MPP parts, potentially saturating channels and
534 /// increasing failure probability for those paths.
536 /// Note that this restriction will be relaxed during pathfinding after paths which meet this
537 /// restriction have been found. While paths which meet this criteria will be searched for, it
538 /// is ultimately up to the scorer to select them over other paths.
540 /// A value of 0 will allow payments up to and including a channel's total announced usable
541 /// capacity, a value of one will only use up to half its capacity, two 1/4, etc.
544 pub max_channel_saturation_power_of_half: u8,
546 /// A list of SCIDs which this payment was previously attempted over and which caused the
547 /// payment to fail. Future attempts for the same payment shouldn't be relayed through any of
549 pub previously_failed_channels: Vec<u64>,
552 impl Writeable for PaymentParameters {
553 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
554 let mut clear_hints = &vec![];
555 let mut blinded_hints = &vec![];
557 Payee::Clear { route_hints, .. } => clear_hints = route_hints,
558 Payee::Blinded { route_hints, .. } => blinded_hints = route_hints,
560 write_tlv_fields!(writer, {
561 (0, self.payee.node_id(), option),
562 (1, self.max_total_cltv_expiry_delta, required),
563 (2, self.payee.features(), option),
564 (3, self.max_path_count, required),
565 (4, *clear_hints, required_vec),
566 (5, self.max_channel_saturation_power_of_half, required),
567 (6, self.expiry_time, option),
568 (7, self.previously_failed_channels, required_vec),
569 (8, *blinded_hints, optional_vec),
570 (9, self.payee.final_cltv_expiry_delta(), option),
576 impl ReadableArgs<u32> for PaymentParameters {
577 fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
578 _init_and_read_tlv_fields!(reader, {
579 (0, payee_pubkey, option),
580 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
581 (2, features, (option: ReadableArgs, payee_pubkey.is_some())),
582 (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
583 (4, clear_route_hints, required_vec),
584 (5, max_channel_saturation_power_of_half, (default_value, DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF)),
585 (6, expiry_time, option),
586 (7, previously_failed_channels, optional_vec),
587 (8, blinded_route_hints, optional_vec),
588 (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
590 let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
591 let payee = if blinded_route_hints.len() != 0 {
592 if clear_route_hints.len() != 0 || payee_pubkey.is_some() { return Err(DecodeError::InvalidValue) }
594 route_hints: blinded_route_hints,
595 features: features.and_then(|f: Features| f.bolt12()),
599 route_hints: clear_route_hints,
600 node_id: payee_pubkey.ok_or(DecodeError::InvalidValue)?,
601 features: features.and_then(|f| f.bolt11()),
602 final_cltv_expiry_delta: final_cltv_expiry_delta.0.unwrap(),
606 max_total_cltv_expiry_delta: _init_tlv_based_struct_field!(max_total_cltv_expiry_delta, (default_value, unused)),
607 max_path_count: _init_tlv_based_struct_field!(max_path_count, (default_value, unused)),
609 max_channel_saturation_power_of_half: _init_tlv_based_struct_field!(max_channel_saturation_power_of_half, (default_value, unused)),
611 previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
617 impl PaymentParameters {
618 /// Creates a payee with the node id of the given `pubkey`.
620 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
622 pub fn from_node_id(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
624 payee: Payee::Clear { node_id: payee_pubkey, route_hints: vec![], features: None, final_cltv_expiry_delta },
626 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
627 max_path_count: DEFAULT_MAX_PATH_COUNT,
628 max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
629 previously_failed_channels: Vec::new(),
633 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
635 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
638 /// Note that MPP keysend is not widely supported yet. The `allow_mpp` lets you choose
639 /// whether your router will be allowed to find a multi-part route for this payment. If you
640 /// set `allow_mpp` to true, you should ensure a payment secret is set on send, likely via
641 /// [`RecipientOnionFields::secret_only`].
643 /// [`RecipientOnionFields::secret_only`]: crate::ln::channelmanager::RecipientOnionFields::secret_only
644 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32, allow_mpp: bool) -> Self {
645 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta)
646 .with_bolt11_features(Bolt11InvoiceFeatures::for_keysend(allow_mpp))
647 .expect("PaymentParameters::from_node_id should always initialize the payee as unblinded")
650 /// Creates parameters for paying to a blinded payee from the provided invoice. Sets
651 /// [`Payee::Blinded::route_hints`], [`Payee::Blinded::features`], and
652 /// [`PaymentParameters::expiry_time`].
653 pub fn from_bolt12_invoice(invoice: &Bolt12Invoice) -> Self {
654 Self::blinded(invoice.payment_paths().to_vec())
655 .with_bolt12_features(invoice.features().clone()).unwrap()
656 .with_expiry_time(invoice.created_at().as_secs().saturating_add(invoice.relative_expiry().as_secs()))
659 fn blinded(blinded_route_hints: Vec<(BlindedPayInfo, BlindedPath)>) -> Self {
661 payee: Payee::Blinded { route_hints: blinded_route_hints, features: None },
663 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
664 max_path_count: DEFAULT_MAX_PATH_COUNT,
665 max_channel_saturation_power_of_half: DEFAULT_MAX_CHANNEL_SATURATION_POW_HALF,
666 previously_failed_channels: Vec::new(),
670 /// Includes the payee's features. Errors if the parameters were not initialized with
671 /// [`PaymentParameters::from_bolt12_invoice`].
673 /// This is not exported to bindings users since bindings don't support move semantics
674 pub fn with_bolt12_features(self, features: Bolt12InvoiceFeatures) -> Result<Self, ()> {
676 Payee::Clear { .. } => Err(()),
677 Payee::Blinded { route_hints, .. } =>
678 Ok(Self { payee: Payee::Blinded { route_hints, features: Some(features) }, ..self })
682 /// Includes the payee's features. Errors if the parameters were initialized with
683 /// [`PaymentParameters::from_bolt12_invoice`].
685 /// This is not exported to bindings users since bindings don't support move semantics
686 pub fn with_bolt11_features(self, features: Bolt11InvoiceFeatures) -> Result<Self, ()> {
688 Payee::Blinded { .. } => Err(()),
689 Payee::Clear { route_hints, node_id, final_cltv_expiry_delta, .. } =>
691 payee: Payee::Clear {
692 route_hints, node_id, features: Some(features), final_cltv_expiry_delta
698 /// Includes hints for routing to the payee. Errors if the parameters were initialized with
699 /// [`PaymentParameters::from_bolt12_invoice`].
701 /// This is not exported to bindings users since bindings don't support move semantics
702 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Result<Self, ()> {
704 Payee::Blinded { .. } => Err(()),
705 Payee::Clear { node_id, features, final_cltv_expiry_delta, .. } =>
707 payee: Payee::Clear {
708 route_hints, node_id, features, final_cltv_expiry_delta,
714 /// Includes a payment expiration in seconds relative to the UNIX epoch.
716 /// This is not exported to bindings users since bindings don't support move semantics
717 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
718 Self { expiry_time: Some(expiry_time), ..self }
721 /// Includes a limit for the total CLTV expiry delta which is considered during routing
723 /// This is not exported to bindings users since bindings don't support move semantics
724 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
725 Self { max_total_cltv_expiry_delta, ..self }
728 /// Includes a limit for the maximum number of payment paths that may be used.
730 /// This is not exported to bindings users since bindings don't support move semantics
731 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
732 Self { max_path_count, ..self }
735 /// Includes a limit for the maximum share of a channel's total capacity that can be sent over, as
736 /// a power of 1/2. See [`PaymentParameters::max_channel_saturation_power_of_half`].
738 /// This is not exported to bindings users since bindings don't support move semantics
739 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
740 Self { max_channel_saturation_power_of_half, ..self }
744 /// The recipient of a payment, differing based on whether they've hidden their identity with route
746 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
748 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
749 /// will be included in the final [`Route`].
751 /// Aggregated routing info and blinded paths, for routing to the payee without knowing their
753 route_hints: Vec<(BlindedPayInfo, BlindedPath)>,
754 /// Features supported by the payee.
756 /// May be set from the payee's invoice. May be `None` if the invoice does not contain any
758 features: Option<Bolt12InvoiceFeatures>,
760 /// The recipient included these route hints in their BOLT11 invoice.
762 /// The node id of the payee.
764 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
765 route_hints: Vec<RouteHint>,
766 /// Features supported by the payee.
768 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
769 /// does not contain any features.
771 /// [`for_keysend`]: PaymentParameters::for_keysend
772 features: Option<Bolt11InvoiceFeatures>,
773 /// The minimum CLTV delta at the end of the route. This value must not be zero.
774 final_cltv_expiry_delta: u32,
779 fn node_id(&self) -> Option<PublicKey> {
781 Self::Clear { node_id, .. } => Some(*node_id),
785 fn node_features(&self) -> Option<NodeFeatures> {
787 Self::Clear { features, .. } => features.as_ref().map(|f| f.to_context()),
788 Self::Blinded { features, .. } => features.as_ref().map(|f| f.to_context()),
791 fn supports_basic_mpp(&self) -> bool {
793 Self::Clear { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
794 Self::Blinded { features, .. } => features.as_ref().map_or(false, |f| f.supports_basic_mpp()),
797 fn features(&self) -> Option<FeaturesRef> {
799 Self::Clear { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt11(f)),
800 Self::Blinded { features, .. } => features.as_ref().map(|f| FeaturesRef::Bolt12(f)),
803 fn final_cltv_expiry_delta(&self) -> Option<u32> {
805 Self::Clear { final_cltv_expiry_delta, .. } => Some(*final_cltv_expiry_delta),
809 fn blinded_route_hints(&self) -> &[(BlindedPayInfo, BlindedPath)] {
811 Self::Blinded { route_hints, .. } => &route_hints[..],
812 Self::Clear { .. } => &[]
816 fn unblinded_route_hints(&self) -> &[RouteHint] {
818 Self::Blinded { .. } => &[],
819 Self::Clear { route_hints, .. } => &route_hints[..]
824 enum FeaturesRef<'a> {
825 Bolt11(&'a Bolt11InvoiceFeatures),
826 Bolt12(&'a Bolt12InvoiceFeatures),
829 Bolt11(Bolt11InvoiceFeatures),
830 Bolt12(Bolt12InvoiceFeatures),
834 fn bolt12(self) -> Option<Bolt12InvoiceFeatures> {
836 Self::Bolt12(f) => Some(f),
840 fn bolt11(self) -> Option<Bolt11InvoiceFeatures> {
842 Self::Bolt11(f) => Some(f),
848 impl<'a> Writeable for FeaturesRef<'a> {
849 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
851 Self::Bolt11(f) => Ok(f.write(w)?),
852 Self::Bolt12(f) => Ok(f.write(w)?),
857 impl ReadableArgs<bool> for Features {
858 fn read<R: io::Read>(reader: &mut R, bolt11: bool) -> Result<Self, DecodeError> {
859 if bolt11 { return Ok(Self::Bolt11(Readable::read(reader)?)) }
860 Ok(Self::Bolt12(Readable::read(reader)?))
864 /// A list of hops along a payment path terminating with a channel to the recipient.
865 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
866 pub struct RouteHint(pub Vec<RouteHintHop>);
868 impl Writeable for RouteHint {
869 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
870 (self.0.len() as u64).write(writer)?;
871 for hop in self.0.iter() {
878 impl Readable for RouteHint {
879 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
880 let hop_count: u64 = Readable::read(reader)?;
881 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
882 for _ in 0..hop_count {
883 hops.push(Readable::read(reader)?);
889 /// A channel descriptor for a hop along a payment path.
890 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd)]
891 pub struct RouteHintHop {
892 /// The node_id of the non-target end of the route
893 pub src_node_id: PublicKey,
894 /// The short_channel_id of this channel
895 pub short_channel_id: u64,
896 /// The fees which must be paid to use this channel
897 pub fees: RoutingFees,
898 /// The difference in CLTV values between this node and the next node.
899 pub cltv_expiry_delta: u16,
900 /// The minimum value, in msat, which must be relayed to the next hop.
901 pub htlc_minimum_msat: Option<u64>,
902 /// The maximum value in msat available for routing with a single HTLC.
903 pub htlc_maximum_msat: Option<u64>,
906 impl_writeable_tlv_based!(RouteHintHop, {
907 (0, src_node_id, required),
908 (1, htlc_minimum_msat, option),
909 (2, short_channel_id, required),
910 (3, htlc_maximum_msat, option),
912 (6, cltv_expiry_delta, required),
915 #[derive(Eq, PartialEq)]
916 struct RouteGraphNode {
918 lowest_fee_to_node: u64,
919 total_cltv_delta: u32,
920 // The maximum value a yet-to-be-constructed payment path might flow through this node.
921 // This value is upper-bounded by us by:
922 // - how much is needed for a path being constructed
923 // - how much value can channels following this node (up to the destination) can contribute,
924 // considering their capacity and fees
925 value_contribution_msat: u64,
926 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
927 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
928 path_htlc_minimum_msat: u64,
929 /// All penalties incurred from this hop on the way to the destination, as calculated using
931 path_penalty_msat: u64,
932 /// The number of hops walked up to this node.
933 path_length_to_node: u8,
936 impl cmp::Ord for RouteGraphNode {
937 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
938 let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat)
939 .saturating_add(other.path_penalty_msat);
940 let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat)
941 .saturating_add(self.path_penalty_msat);
942 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
946 impl cmp::PartialOrd for RouteGraphNode {
947 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
948 Some(self.cmp(other))
952 /// A wrapper around the various hop representations.
954 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
955 #[derive(Clone, Debug)]
956 enum CandidateRouteHop<'a> {
957 /// A hop from the payer, where the outbound liquidity is known.
959 details: &'a ChannelDetails,
961 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
963 info: DirectedChannelInfo<'a>,
964 short_channel_id: u64,
966 /// A hop to the payee found in the BOLT 11 payment invoice, though not necessarily a direct
969 hint: &'a RouteHintHop,
971 /// The payee's identity is concealed behind blinded paths provided in a BOLT 12 invoice.
973 hint: &'a (BlindedPayInfo, BlindedPath),
976 /// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided
977 /// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the
978 /// introduction node and the destination. Useful for tracking that we need to include a blinded
979 /// path at the end of our [`Route`].
981 hint: &'a (BlindedPayInfo, BlindedPath),
986 impl<'a> CandidateRouteHop<'a> {
987 fn short_channel_id(&self) -> Option<u64> {
989 CandidateRouteHop::FirstHop { details } => Some(details.get_outbound_payment_scid().unwrap()),
990 CandidateRouteHop::PublicHop { short_channel_id, .. } => Some(*short_channel_id),
991 CandidateRouteHop::PrivateHop { hint } => Some(hint.short_channel_id),
992 CandidateRouteHop::Blinded { .. } => None,
993 CandidateRouteHop::OneHopBlinded { .. } => None,
997 // NOTE: This may alloc memory so avoid calling it in a hot code path.
998 fn features(&self) -> ChannelFeatures {
1000 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
1001 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
1002 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
1003 CandidateRouteHop::Blinded { .. } => ChannelFeatures::empty(),
1004 CandidateRouteHop::OneHopBlinded { .. } => ChannelFeatures::empty(),
1008 fn cltv_expiry_delta(&self) -> u32 {
1010 CandidateRouteHop::FirstHop { .. } => 0,
1011 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
1012 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
1013 CandidateRouteHop::Blinded { hint, .. } => hint.0.cltv_expiry_delta as u32,
1014 CandidateRouteHop::OneHopBlinded { .. } => 0,
1018 fn htlc_minimum_msat(&self) -> u64 {
1020 CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat,
1021 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
1022 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
1023 CandidateRouteHop::Blinded { hint, .. } => hint.0.htlc_minimum_msat,
1024 CandidateRouteHop::OneHopBlinded { .. } => 0,
1028 fn fees(&self) -> RoutingFees {
1030 CandidateRouteHop::FirstHop { .. } => RoutingFees {
1031 base_msat: 0, proportional_millionths: 0,
1033 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
1034 CandidateRouteHop::PrivateHop { hint } => hint.fees,
1035 CandidateRouteHop::Blinded { hint, .. } => {
1037 base_msat: hint.0.fee_base_msat,
1038 proportional_millionths: hint.0.fee_proportional_millionths
1041 CandidateRouteHop::OneHopBlinded { .. } =>
1042 RoutingFees { base_msat: 0, proportional_millionths: 0 },
1046 fn effective_capacity(&self) -> EffectiveCapacity {
1048 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
1049 liquidity_msat: details.next_outbound_htlc_limit_msat,
1051 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
1052 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
1053 EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
1054 CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
1055 EffectiveCapacity::Infinite,
1056 CandidateRouteHop::Blinded { hint, .. } =>
1057 EffectiveCapacity::HintMaxHTLC { amount_msat: hint.0.htlc_maximum_msat },
1058 CandidateRouteHop::OneHopBlinded { .. } => EffectiveCapacity::Infinite,
1062 fn id(&self, channel_direction: bool /* src_node_id < target_node_id */) -> CandidateHopId {
1064 CandidateRouteHop::Blinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
1065 CandidateRouteHop::OneHopBlinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
1066 _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), channel_direction)),
1069 fn blinded_path(&self) -> Option<&'a BlindedPath> {
1071 CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
1079 #[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)]
1080 enum CandidateHopId {
1081 /// Contains (scid, src_node_id < target_node_id)
1083 /// Index of the blinded route hint in [`Payee::Blinded::route_hints`].
1088 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
1089 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
1091 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
1092 EffectiveCapacity::Infinite => u64::max_value(),
1093 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
1094 EffectiveCapacity::AdvertisedMaxHTLC { amount_msat } =>
1095 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
1096 // Treat htlc_maximum_msat from a route hint as an exact liquidity amount, since the invoice is
1097 // expected to have been generated from up-to-date capacity information.
1098 EffectiveCapacity::HintMaxHTLC { amount_msat } => amount_msat,
1099 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
1100 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
1104 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
1105 -> bool where I1::Item: PartialEq<I2::Item> {
1107 let a = iter_a.next();
1108 let b = iter_b.next();
1109 if a.is_none() && b.is_none() { return true; }
1110 if a.is_none() || b.is_none() { return false; }
1111 if a.unwrap().ne(&b.unwrap()) { return false; }
1115 /// It's useful to keep track of the hops associated with the fees required to use them,
1116 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
1117 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
1118 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
1120 struct PathBuildingHop<'a> {
1121 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
1122 // is a larger refactor and will require careful performance analysis.
1124 candidate: CandidateRouteHop<'a>,
1127 /// All the fees paid *after* this channel on the way to the destination
1128 next_hops_fee_msat: u64,
1129 /// Fee paid for the use of the current channel (see candidate.fees()).
1130 /// The value will be actually deducted from the counterparty balance on the previous link.
1131 hop_use_fee_msat: u64,
1132 /// Used to compare channels when choosing the for routing.
1133 /// Includes paying for the use of a hop and the following hops, as well as
1134 /// an estimated cost of reaching this hop.
1135 /// Might get stale when fees are recomputed. Primarily for internal use.
1136 total_fee_msat: u64,
1137 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
1138 /// walk and may be invalid thereafter.
1139 path_htlc_minimum_msat: u64,
1140 /// All penalties incurred from this channel on the way to the destination, as calculated using
1141 /// channel scoring.
1142 path_penalty_msat: u64,
1143 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
1144 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
1145 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
1146 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
1147 /// avoid processing them again.
1148 was_processed: bool,
1149 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1150 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
1151 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
1152 // value_contribution_msat, which requires tracking it here. See comments below where it is
1153 // used for more info.
1154 value_contribution_msat: u64,
1157 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
1158 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1159 let mut debug_struct = f.debug_struct("PathBuildingHop");
1161 .field("node_id", &self.node_id)
1162 .field("short_channel_id", &self.candidate.short_channel_id())
1163 .field("total_fee_msat", &self.total_fee_msat)
1164 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
1165 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
1166 .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)))
1167 .field("path_penalty_msat", &self.path_penalty_msat)
1168 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
1169 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
1170 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1171 let debug_struct = debug_struct
1172 .field("value_contribution_msat", &self.value_contribution_msat);
1173 debug_struct.finish()
1177 // Instantiated with a list of hops with correct data in them collected during path finding,
1178 // an instance of this struct should be further modified only via given methods.
1180 struct PaymentPath<'a> {
1181 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
1184 impl<'a> PaymentPath<'a> {
1185 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
1186 fn get_value_msat(&self) -> u64 {
1187 self.hops.last().unwrap().0.fee_msat
1190 fn get_path_penalty_msat(&self) -> u64 {
1191 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
1194 fn get_total_fee_paid_msat(&self) -> u64 {
1195 if self.hops.len() < 1 {
1199 // Can't use next_hops_fee_msat because it gets outdated.
1200 for (i, (hop, _)) in self.hops.iter().enumerate() {
1201 if i != self.hops.len() - 1 {
1202 result += hop.fee_msat;
1208 fn get_cost_msat(&self) -> u64 {
1209 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
1212 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
1213 // to change fees may result in an inconsistency.
1215 // Sometimes we call this function right after constructing a path which is inconsistent in
1216 // that it the value being transferred has decreased while we were doing path finding, leading
1217 // to the fees being paid not lining up with the actual limits.
1219 // Note that this function is not aware of the available_liquidity limit, and thus does not
1220 // support increasing the value being transferred beyond what was selected during the initial
1222 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
1223 let mut total_fee_paid_msat = 0 as u64;
1224 for i in (0..self.hops.len()).rev() {
1225 let last_hop = i == self.hops.len() - 1;
1227 // For non-last-hop, this value will represent the fees paid on the current hop. It
1228 // will consist of the fees for the use of the next hop, and extra fees to match
1229 // htlc_minimum_msat of the current channel. Last hop is handled separately.
1230 let mut cur_hop_fees_msat = 0;
1232 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
1235 let cur_hop = &mut self.hops.get_mut(i).unwrap().0;
1236 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
1237 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
1238 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
1239 // set it too high just to maliciously take more fees by exploiting this
1240 // match htlc_minimum_msat logic.
1241 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
1242 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
1243 // Note that there is a risk that *previous hops* (those closer to us, as we go
1244 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
1246 // This might make us end up with a broken route, although this should be super-rare
1247 // in practice, both because of how healthy channels look like, and how we pick
1248 // channels in add_entry.
1249 // Also, this can't be exploited more heavily than *announce a free path and fail
1251 cur_hop_transferred_amount_msat += extra_fees_msat;
1252 total_fee_paid_msat += extra_fees_msat;
1253 cur_hop_fees_msat += extra_fees_msat;
1257 // Final hop is a special case: it usually has just value_msat (by design), but also
1258 // it still could overpay for the htlc_minimum_msat.
1259 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
1261 // Propagate updated fees for the use of the channels to one hop back, where they
1262 // will be actually paid (fee_msat). The last hop is handled above separately.
1263 cur_hop.fee_msat = cur_hop_fees_msat;
1266 // Fee for the use of the current hop which will be deducted on the previous hop.
1267 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
1268 // this channel is free for us.
1270 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
1271 cur_hop.hop_use_fee_msat = new_fee;
1272 total_fee_paid_msat += new_fee;
1274 // It should not be possible because this function is called only to reduce the
1275 // value. In that case, compute_fee was already called with the same fees for
1276 // larger amount and there was no overflow.
1285 /// Calculate the fees required to route the given amount over a channel with the given fees.
1286 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
1287 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1288 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
1292 /// Calculate the fees required to route the given amount over a channel with the given fees,
1293 /// saturating to [`u64::max_value`].
1294 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
1295 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1296 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
1297 .saturating_add(channel_fees.base_msat as u64)
1300 /// The default `features` we assume for a node in a route, when no `features` are known about that
1303 /// Default features are:
1304 /// * variable_length_onion_optional
1305 fn default_node_features() -> NodeFeatures {
1306 let mut features = NodeFeatures::empty();
1307 features.set_variable_length_onion_optional();
1311 struct LoggedPayeePubkey(Option<PublicKey>);
1312 impl fmt::Display for LoggedPayeePubkey {
1313 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1316 "payee node id ".fmt(f)?;
1320 "blinded payee".fmt(f)
1326 struct LoggedCandidateHop<'a>(&'a CandidateRouteHop<'a>);
1327 impl<'a> fmt::Display for LoggedCandidateHop<'a> {
1328 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1330 CandidateRouteHop::Blinded { hint, .. } | CandidateRouteHop::OneHopBlinded { hint, .. } => {
1331 "blinded route hint with introduction node id ".fmt(f)?;
1332 hint.1.introduction_node_id.fmt(f)?;
1333 " and blinding point ".fmt(f)?;
1334 hint.1.blinding_point.fmt(f)
1338 self.0.short_channel_id().unwrap().fmt(f)
1345 fn sort_first_hop_channels(
1346 channels: &mut Vec<&ChannelDetails>, used_liquidities: &HashMap<CandidateHopId, u64>,
1347 recommended_value_msat: u64, our_node_pubkey: &PublicKey
1349 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1350 // most like to use.
1352 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1353 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1356 // Second, because simply always sorting in descending order would always use our largest
1357 // available outbound capacity, needlessly fragmenting our available channel capacities,
1358 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1359 // which have enough, but not too much, capacity for the payment.
1361 // Available outbound balances factor in liquidity already reserved for previously found paths.
1362 channels.sort_unstable_by(|chan_a, chan_b| {
1363 let chan_a_outbound_limit_msat = chan_a.next_outbound_htlc_limit_msat
1364 .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_a.get_outbound_payment_scid().unwrap(),
1365 our_node_pubkey < &chan_a.counterparty.node_id))).unwrap_or(&0));
1366 let chan_b_outbound_limit_msat = chan_b.next_outbound_htlc_limit_msat
1367 .saturating_sub(*used_liquidities.get(&CandidateHopId::Clear((chan_b.get_outbound_payment_scid().unwrap(),
1368 our_node_pubkey < &chan_b.counterparty.node_id))).unwrap_or(&0));
1369 if chan_b_outbound_limit_msat < recommended_value_msat || chan_a_outbound_limit_msat < recommended_value_msat {
1370 // Sort in descending order
1371 chan_b_outbound_limit_msat.cmp(&chan_a_outbound_limit_msat)
1373 // Sort in ascending order
1374 chan_a_outbound_limit_msat.cmp(&chan_b_outbound_limit_msat)
1379 /// Finds a route from us (payer) to the given target node (payee).
1381 /// If the payee provided features in their invoice, they should be provided via the `payee` field
1382 /// in the given [`RouteParameters::payment_params`].
1383 /// Without this, MPP will only be used if the payee's features are available in the network graph.
1385 /// Private routing paths between a public node and the target may be included in the `payee` field
1386 /// of [`RouteParameters::payment_params`].
1388 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
1389 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
1390 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
1392 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1393 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1394 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1398 /// Panics if first_hops contains channels without `short_channel_id`s;
1399 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1401 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1402 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1403 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1404 pub fn find_route<L: Deref, GL: Deref, S: Score>(
1405 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1406 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1407 scorer: &S, score_params: &S::ScoreParams, random_seed_bytes: &[u8; 32]
1408 ) -> Result<Route, LightningError>
1409 where L::Target: Logger, GL::Target: Logger {
1410 let graph_lock = network_graph.read_only();
1411 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
1412 route_params.final_value_msat, logger, scorer, score_params,
1413 random_seed_bytes)?;
1414 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1418 pub(crate) fn get_route<L: Deref, S: Score>(
1419 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
1420 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, logger: L, scorer: &S, score_params: &S::ScoreParams,
1421 _random_seed_bytes: &[u8; 32]
1422 ) -> Result<Route, LightningError>
1423 where L::Target: Logger {
1424 // If we're routing to a blinded recipient, we won't have their node id. Therefore, keep the
1425 // unblinded payee id as an option. We also need a non-optional "payee id" for path construction,
1426 // so use a dummy id for this in the blinded case.
1427 let payee_node_id_opt = payment_params.payee.node_id().map(|pk| NodeId::from_pubkey(&pk));
1428 const DUMMY_BLINDED_PAYEE_ID: [u8; 33] = [2; 33];
1429 let maybe_dummy_payee_pk = payment_params.payee.node_id().unwrap_or_else(|| PublicKey::from_slice(&DUMMY_BLINDED_PAYEE_ID).unwrap());
1430 let maybe_dummy_payee_node_id = NodeId::from_pubkey(&maybe_dummy_payee_pk);
1431 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1433 if payee_node_id_opt.map_or(false, |payee| payee == our_node_id) {
1434 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1437 if final_value_msat > MAX_VALUE_MSAT {
1438 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1441 if final_value_msat == 0 {
1442 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1445 match &payment_params.payee {
1446 Payee::Clear { route_hints, node_id, .. } => {
1447 for route in route_hints.iter() {
1448 for hop in &route.0 {
1449 if hop.src_node_id == *node_id {
1450 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1455 Payee::Blinded { route_hints, .. } => {
1456 if route_hints.iter().all(|(_, path)| &path.introduction_node_id == our_node_pubkey) {
1457 return Err(LightningError{err: "Cannot generate a route to blinded paths if we are the introduction node to all of them".to_owned(), action: ErrorAction::IgnoreError});
1459 for (_, blinded_path) in route_hints.iter() {
1460 if blinded_path.blinded_hops.len() == 0 {
1461 return Err(LightningError{err: "0-hop blinded path provided".to_owned(), action: ErrorAction::IgnoreError});
1462 } else if &blinded_path.introduction_node_id == our_node_pubkey {
1463 log_info!(logger, "Got blinded path with ourselves as the introduction node, ignoring");
1464 } else if blinded_path.blinded_hops.len() == 1 &&
1465 route_hints.iter().any( |(_, p)| p.blinded_hops.len() == 1
1466 && p.introduction_node_id != blinded_path.introduction_node_id)
1468 return Err(LightningError{err: format!("1-hop blinded paths must all have matching introduction node ids"), action: ErrorAction::IgnoreError});
1473 let final_cltv_expiry_delta = payment_params.payee.final_cltv_expiry_delta().unwrap_or(0);
1474 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1475 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});
1478 // The general routing idea is the following:
1479 // 1. Fill first/last hops communicated by the caller.
1480 // 2. Attempt to construct a path from payer to payee for transferring
1481 // any ~sufficient (described later) value.
1482 // If succeed, remember which channels were used and how much liquidity they have available,
1483 // so that future paths don't rely on the same liquidity.
1484 // 3. Proceed to the next step if:
1485 // - we hit the recommended target value;
1486 // - OR if we could not construct a new path. Any next attempt will fail too.
1487 // Otherwise, repeat step 2.
1488 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1489 // (not recommended value).
1490 // 5. If yes, proceed. If not, fail routing.
1491 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1492 // transferred up to the transfer target value.
1493 // 7. Reduce the value of the last path until we are sending only the target value.
1494 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1495 // them so that we're not sending two HTLCs along the same path.
1497 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1498 // distance from the payee
1500 // We are not a faithful Dijkstra's implementation because we can change values which impact
1501 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1502 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1503 // the value we are currently attempting to send over a path, we simply reduce the value being
1504 // sent along the path for any hops after that channel. This may imply that later fees (which
1505 // we've already tabulated) are lower because a smaller value is passing through the channels
1506 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1507 // channels which were selected earlier (and which may still be used for other paths without a
1508 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1511 // One potentially problematic case for this algorithm would be if there are many
1512 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1513 // graph walking), we may never find a path which is not liquidity-limited and has lower
1514 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1515 // Because we only consider paths with at least 5% of the total value being sent, the damage
1516 // from such a case should be limited, however this could be further reduced in the future by
1517 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1518 // limits for the purposes of fee calculation.
1520 // Alternatively, we could store more detailed path information in the heap (targets, below)
1521 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1522 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1523 // and practically (as we would need to store dynamically-allocated path information in heap
1524 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
1525 // results of such an algorithm would likely be biased towards lower-value paths.
1527 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
1528 // outside of our current search value, running a path search more times to gather candidate
1529 // paths at different values. While this may be acceptable, further path searches may increase
1530 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
1531 // graph for candidate paths, calculating the maximum value which can realistically be sent at
1532 // the same time, remaining generic across different payment values.
1534 let network_channels = network_graph.channels();
1535 let network_nodes = network_graph.nodes();
1537 if payment_params.max_path_count == 0 {
1538 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
1541 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
1542 // it. If the payee supports it they're supposed to include it in the invoice, so that should
1544 let allow_mpp = if payment_params.max_path_count == 1 {
1546 } else if payment_params.payee.supports_basic_mpp() {
1548 } else if let Some(payee) = payee_node_id_opt {
1549 network_nodes.get(&payee).map_or(false, |node| node.announcement_info.as_ref().map_or(false,
1550 |info| info.features.supports_basic_mpp()))
1553 log_trace!(logger, "Searching for a route from payer {} to {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
1554 LoggedPayeePubkey(payment_params.payee.node_id()), if allow_mpp { "with" } else { "without" },
1555 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
1558 // Prepare the data we'll use for payee-to-payer search by
1559 // inserting first hops suggested by the caller as targets.
1560 // Our search will then attempt to reach them while traversing from the payee node.
1561 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
1562 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
1563 if let Some(hops) = first_hops {
1565 if chan.get_outbound_payment_scid().is_none() {
1566 panic!("first_hops should be filled in with usable channels, not pending ones");
1568 if chan.counterparty.node_id == *our_node_pubkey {
1569 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
1572 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
1573 .or_insert(Vec::new())
1576 if first_hop_targets.is_empty() {
1577 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
1581 // The main heap containing all candidate next-hops sorted by their score (max(fee,
1582 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
1583 // adding duplicate entries when we find a better path to a given node.
1584 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
1586 // Map from node_id to information about the best current path to that node, including feerate
1588 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
1590 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
1591 // indicating that we may wish to try again with a higher value, potentially paying to meet an
1592 // htlc_minimum with extra fees while still finding a cheaper path.
1593 let mut hit_minimum_limit;
1595 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
1596 // We start with a path_value of the exact amount we want, and if that generates a route we may
1597 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
1598 // amount we want in total across paths, selecting the best subset at the end.
1599 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
1600 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
1601 let mut path_value_msat = final_value_msat;
1603 // Routing Fragmentation Mitigation heuristic:
1605 // Routing fragmentation across many payment paths increases the overall routing
1606 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
1607 // Taking too many smaller paths also increases the chance of payment failure.
1608 // Thus to avoid this effect, we require from our collected links to provide
1609 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
1610 // This requirement is currently set to be 1/max_path_count of the payment
1611 // value to ensure we only ever return routes that do not violate this limit.
1612 let minimal_value_contribution_msat: u64 = if allow_mpp {
1613 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
1618 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
1619 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
1620 // drop the requirement by setting this to 0.
1621 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
1623 // Keep track of how much liquidity has been used in selected channels or blinded paths. Used to
1624 // determine if the channel can be used by additional MPP paths or to inform path finding
1625 // decisions. It is aware of direction *only* to ensure that the correct htlc_maximum_msat value
1626 // is used. Hence, liquidity used in one direction will not offset any used in the opposite
1628 let mut used_liquidities: HashMap<CandidateHopId, u64> =
1629 HashMap::with_capacity(network_nodes.len());
1631 // Keeping track of how much value we already collected across other paths. Helps to decide
1632 // when we want to stop looking for new paths.
1633 let mut already_collected_value_msat = 0;
1635 for (_, channels) in first_hop_targets.iter_mut() {
1636 sort_first_hop_channels(channels, &used_liquidities, recommended_value_msat,
1640 log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
1641 LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
1643 macro_rules! add_entry {
1644 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
1645 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
1646 // since that value has to be transferred over this channel.
1647 // Returns whether this channel caused an update to `targets`.
1648 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
1649 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
1650 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
1651 // We "return" whether we updated the path at the end, and how much we can route via
1652 // this channel, via this:
1653 let mut did_add_update_path_to_src_node = None;
1654 // Channels to self should not be used. This is more of belt-and-suspenders, because in
1655 // practice these cases should be caught earlier:
1656 // - for regular channels at channel announcement (TODO)
1657 // - for first and last hops early in get_route
1658 if $src_node_id != $dest_node_id {
1659 let scid_opt = $candidate.short_channel_id();
1660 let effective_capacity = $candidate.effective_capacity();
1661 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
1663 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
1664 // It may be misleading because we might later choose to reduce the value transferred
1665 // over these channels, and the channel which was insufficient might become sufficient.
1666 // Worst case: we drop a good channel here because it can't cover the high following
1667 // fees caused by one expensive channel, but then this channel could have been used
1668 // if the amount being transferred over this path is lower.
1669 // We do this for now, but this is a subject for removal.
1670 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
1671 let used_liquidity_msat = used_liquidities
1672 .get(&$candidate.id($src_node_id < $dest_node_id))
1673 .map_or(0, |used_liquidity_msat| {
1674 available_value_contribution_msat = available_value_contribution_msat
1675 .saturating_sub(*used_liquidity_msat);
1676 *used_liquidity_msat
1679 // Verify the liquidity offered by this channel complies to the minimal contribution.
1680 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
1681 // Do not consider candidate hops that would exceed the maximum path length.
1682 let path_length_to_node = $next_hops_path_length + 1;
1683 let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
1685 // Do not consider candidates that exceed the maximum total cltv expiry limit.
1686 // In order to already account for some of the privacy enhancing random CLTV
1687 // expiry delta offset we add on top later, we subtract a rough estimate
1688 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
1689 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
1690 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
1691 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
1692 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
1693 .saturating_add($candidate.cltv_expiry_delta());
1694 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
1696 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
1697 // Includes paying fees for the use of the following channels.
1698 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
1699 Some(result) => result,
1700 // Can't overflow due to how the values were computed right above.
1701 None => unreachable!(),
1703 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1704 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
1705 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
1707 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1708 let may_overpay_to_meet_path_minimum_msat =
1709 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
1710 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
1711 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
1712 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
1714 let payment_failed_on_this_channel = scid_opt.map_or(false,
1715 |scid| payment_params.previously_failed_channels.contains(&scid));
1717 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
1718 // bother considering this channel. If retrying with recommended_value_msat may
1719 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
1720 // around again with a higher amount.
1721 if !contributes_sufficient_value || exceeds_max_path_length ||
1722 exceeds_cltv_delta_limit || payment_failed_on_this_channel {
1723 // Path isn't useful, ignore it and move on.
1724 } else if may_overpay_to_meet_path_minimum_msat {
1725 hit_minimum_limit = true;
1726 } else if over_path_minimum_msat {
1727 // Note that low contribution here (limited by available_liquidity_msat)
1728 // might violate htlc_minimum_msat on the hops which are next along the
1729 // payment path (upstream to the payee). To avoid that, we recompute
1730 // path fees knowing the final path contribution after constructing it.
1731 let path_htlc_minimum_msat = cmp::max(
1732 compute_fees_saturating($next_hops_path_htlc_minimum_msat, $candidate.fees())
1733 .saturating_add($next_hops_path_htlc_minimum_msat),
1734 $candidate.htlc_minimum_msat());
1735 let hm_entry = dist.entry($src_node_id);
1736 let old_entry = hm_entry.or_insert_with(|| {
1737 // If there was previously no known way to access the source node
1738 // (recall it goes payee-to-payer) of short_channel_id, first add a
1739 // semi-dummy record just to compute the fees to reach the source node.
1740 // This will affect our decision on selecting short_channel_id
1741 // as a way to reach the $dest_node_id.
1743 node_id: $dest_node_id.clone(),
1744 candidate: $candidate.clone(),
1746 next_hops_fee_msat: u64::max_value(),
1747 hop_use_fee_msat: u64::max_value(),
1748 total_fee_msat: u64::max_value(),
1749 path_htlc_minimum_msat,
1750 path_penalty_msat: u64::max_value(),
1751 was_processed: false,
1752 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1753 value_contribution_msat,
1757 #[allow(unused_mut)] // We only use the mut in cfg(test)
1758 let mut should_process = !old_entry.was_processed;
1759 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1761 // In test/fuzzing builds, we do extra checks to make sure the skipping
1762 // of already-seen nodes only happens in cases we expect (see below).
1763 if !should_process { should_process = true; }
1767 let mut hop_use_fee_msat = 0;
1768 let mut total_fee_msat: u64 = $next_hops_fee_msat;
1770 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1771 // will have the same effective-fee
1772 if $src_node_id != our_node_id {
1773 // Note that `u64::max_value` means we'll always fail the
1774 // `old_entry.total_fee_msat > total_fee_msat` check below
1775 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
1776 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
1779 let channel_usage = ChannelUsage {
1780 amount_msat: amount_to_transfer_over_msat,
1781 inflight_htlc_msat: used_liquidity_msat,
1784 let channel_penalty_msat = scid_opt.map_or(0,
1785 |scid| scorer.channel_penalty_msat(scid, &$src_node_id, &$dest_node_id,
1786 channel_usage, score_params));
1787 let path_penalty_msat = $next_hops_path_penalty_msat
1788 .saturating_add(channel_penalty_msat);
1789 let new_graph_node = RouteGraphNode {
1790 node_id: $src_node_id,
1791 lowest_fee_to_node: total_fee_msat,
1792 total_cltv_delta: hop_total_cltv_delta,
1793 value_contribution_msat,
1794 path_htlc_minimum_msat,
1796 path_length_to_node,
1799 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1800 // if this way is cheaper than the already known
1801 // (considering the cost to "reach" this channel from the route destination,
1802 // the cost of using this channel,
1803 // and the cost of routing to the source node of this channel).
1804 // Also, consider that htlc_minimum_msat_difference, because we might end up
1805 // paying it. Consider the following exploit:
1806 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1807 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1808 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1809 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1811 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1812 // but it may require additional tracking - we don't want to double-count
1813 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1814 // can't use something that may decrease on future hops.
1815 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1816 .saturating_add(old_entry.path_penalty_msat);
1817 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1818 .saturating_add(path_penalty_msat);
1820 if !old_entry.was_processed && new_cost < old_cost {
1821 targets.push(new_graph_node);
1822 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1823 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1824 old_entry.total_fee_msat = total_fee_msat;
1825 old_entry.node_id = $dest_node_id.clone();
1826 old_entry.candidate = $candidate.clone();
1827 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1828 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1829 old_entry.path_penalty_msat = path_penalty_msat;
1830 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1832 old_entry.value_contribution_msat = value_contribution_msat;
1834 did_add_update_path_to_src_node = Some(value_contribution_msat);
1835 } else if old_entry.was_processed && new_cost < old_cost {
1836 #[cfg(all(not(ldk_bench), any(test, fuzzing)))]
1838 // If we're skipping processing a node which was previously
1839 // processed even though we found another path to it with a
1840 // cheaper fee, check that it was because the second path we
1841 // found (which we are processing now) has a lower value
1842 // contribution due to an HTLC minimum limit.
1844 // e.g. take a graph with two paths from node 1 to node 2, one
1845 // through channel A, and one through channel B. Channel A and
1846 // B are both in the to-process heap, with their scores set by
1847 // a higher htlc_minimum than fee.
1848 // Channel A is processed first, and the channels onwards from
1849 // node 1 are added to the to-process heap. Thereafter, we pop
1850 // Channel B off of the heap, note that it has a much more
1851 // restrictive htlc_maximum_msat, and recalculate the fees for
1852 // all of node 1's channels using the new, reduced, amount.
1854 // This would be bogus - we'd be selecting a higher-fee path
1855 // with a lower htlc_maximum_msat instead of the one we'd
1856 // already decided to use.
1857 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1859 value_contribution_msat + path_penalty_msat <
1860 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1868 did_add_update_path_to_src_node
1872 let default_node_features = default_node_features();
1874 // Find ways (channels with destination) to reach a given node and store them
1875 // in the corresponding data structures (routing graph etc).
1876 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1877 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1878 // This data can later be helpful to optimize routing (pay lower fees).
1879 macro_rules! add_entries_to_cheapest_to_target_node {
1880 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1881 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1882 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1883 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1884 let was_processed = elem.was_processed;
1885 elem.was_processed = true;
1888 // Entries are added to dist in add_entry!() when there is a channel from a node.
1889 // Because there are no channels from payee, it will not have a dist entry at this point.
1890 // If we're processing any other node, it is always be the result of a channel from it.
1891 debug_assert_eq!($node_id, maybe_dummy_payee_node_id);
1896 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1897 for details in first_channels {
1898 let candidate = CandidateRouteHop::FirstHop { details };
1899 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1900 $next_hops_value_contribution,
1901 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1902 $next_hops_cltv_delta, $next_hops_path_length);
1906 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1909 &default_node_features
1912 if !features.requires_unknown_bits() {
1913 for chan_id in $node.channels.iter() {
1914 let chan = network_channels.get(chan_id).unwrap();
1915 if !chan.features.requires_unknown_bits() {
1916 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
1917 if first_hops.is_none() || *source != our_node_id {
1918 if directed_channel.direction().enabled {
1919 let candidate = CandidateRouteHop::PublicHop {
1920 info: directed_channel,
1921 short_channel_id: *chan_id,
1923 add_entry!(candidate, *source, $node_id,
1924 $fee_to_target_msat,
1925 $next_hops_value_contribution,
1926 $next_hops_path_htlc_minimum_msat,
1927 $next_hops_path_penalty_msat,
1928 $next_hops_cltv_delta, $next_hops_path_length);
1939 let mut payment_paths = Vec::<PaymentPath>::new();
1941 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1942 'paths_collection: loop {
1943 // For every new path, start from scratch, except for used_liquidities, which
1944 // helps to avoid reusing previously selected paths in future iterations.
1947 hit_minimum_limit = false;
1949 // If first hop is a private channel and the only way to reach the payee, this is the only
1950 // place where it could be added.
1951 payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| {
1952 for details in first_channels {
1953 let candidate = CandidateRouteHop::FirstHop { details };
1954 let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
1955 0, 0u64, 0, 0).is_some();
1956 log_trace!(logger, "{} direct route to payee via {}",
1957 if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate));
1961 // Add the payee as a target, so that the payee-to-payer
1962 // search algorithm knows what to start with.
1963 payee_node_id_opt.map(|payee| match network_nodes.get(&payee) {
1964 // The payee is not in our network graph, so nothing to add here.
1965 // There is still a chance of reaching them via last_hops though,
1966 // so don't yet fail the payment here.
1967 // If not, targets.pop() will not even let us enter the loop in step 2.
1970 add_entries_to_cheapest_to_target_node!(node, payee, 0, path_value_msat, 0, 0u64, 0, 0);
1975 // If a caller provided us with last hops, add them to routing targets. Since this happens
1976 // earlier than general path finding, they will be somewhat prioritized, although currently
1977 // it matters only if the fees are exactly the same.
1978 for (hint_idx, hint) in payment_params.payee.blinded_route_hints().iter().enumerate() {
1979 let intro_node_id = NodeId::from_pubkey(&hint.1.introduction_node_id);
1980 let have_intro_node_in_graph =
1981 // Only add the hops in this route to our candidate set if either
1982 // we have a direct channel to the first hop or the first hop is
1983 // in the regular network graph.
1984 first_hop_targets.get(&intro_node_id).is_some() ||
1985 network_nodes.get(&intro_node_id).is_some();
1986 if !have_intro_node_in_graph { continue }
1987 let candidate = if hint.1.blinded_hops.len() == 1 {
1988 CandidateRouteHop::OneHopBlinded { hint, hint_idx }
1989 } else { CandidateRouteHop::Blinded { hint, hint_idx } };
1990 let mut path_contribution_msat = path_value_msat;
1991 if let Some(hop_used_msat) = add_entry!(candidate, intro_node_id, maybe_dummy_payee_node_id,
1992 0, path_contribution_msat, 0, 0_u64, 0, 0)
1994 path_contribution_msat = hop_used_msat;
1996 if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hint.1.introduction_node_id)) {
1997 sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat,
1999 for details in first_channels {
2000 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
2001 add_entry!(first_hop_candidate, our_node_id, intro_node_id, 0, path_contribution_msat, 0,
2006 for route in payment_params.payee.unblinded_route_hints().iter()
2007 .filter(|route| !route.0.is_empty())
2009 let first_hop_in_route = &(route.0)[0];
2010 let have_hop_src_in_graph =
2011 // Only add the hops in this route to our candidate set if either
2012 // we have a direct channel to the first hop or the first hop is
2013 // in the regular network graph.
2014 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
2015 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
2016 if have_hop_src_in_graph {
2017 // We start building the path from reverse, i.e., from payee
2018 // to the first RouteHintHop in the path.
2019 let hop_iter = route.0.iter().rev();
2020 let prev_hop_iter = core::iter::once(&maybe_dummy_payee_pk).chain(
2021 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
2022 let mut hop_used = true;
2023 let mut aggregate_next_hops_fee_msat: u64 = 0;
2024 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
2025 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
2026 let mut aggregate_next_hops_cltv_delta: u32 = 0;
2027 let mut aggregate_next_hops_path_length: u8 = 0;
2028 let mut aggregate_path_contribution_msat = path_value_msat;
2030 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
2031 let source = NodeId::from_pubkey(&hop.src_node_id);
2032 let target = NodeId::from_pubkey(&prev_hop_id);
2033 let candidate = network_channels
2034 .get(&hop.short_channel_id)
2035 .and_then(|channel| channel.as_directed_to(&target))
2036 .map(|(info, _)| CandidateRouteHop::PublicHop {
2038 short_channel_id: hop.short_channel_id,
2040 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
2042 if let Some(hop_used_msat) = add_entry!(candidate, source, target,
2043 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
2044 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
2045 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
2047 aggregate_path_contribution_msat = hop_used_msat;
2049 // If this hop was not used then there is no use checking the preceding
2050 // hops in the RouteHint. We can break by just searching for a direct
2051 // channel between last checked hop and first_hop_targets.
2055 let used_liquidity_msat = used_liquidities
2056 .get(&candidate.id(source < target)).copied()
2058 let channel_usage = ChannelUsage {
2059 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
2060 inflight_htlc_msat: used_liquidity_msat,
2061 effective_capacity: candidate.effective_capacity(),
2063 let channel_penalty_msat = scorer.channel_penalty_msat(
2064 hop.short_channel_id, &source, &target, channel_usage, score_params
2066 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
2067 .saturating_add(channel_penalty_msat);
2069 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
2070 .saturating_add(hop.cltv_expiry_delta as u32);
2072 aggregate_next_hops_path_length = aggregate_next_hops_path_length
2075 // Searching for a direct channel between last checked hop and first_hop_targets
2076 if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&prev_hop_id)) {
2077 sort_first_hop_channels(first_channels, &used_liquidities,
2078 recommended_value_msat, our_node_pubkey);
2079 for details in first_channels {
2080 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
2081 add_entry!(first_hop_candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
2082 aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
2083 aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
2084 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
2092 // In the next values of the iterator, the aggregate fees already reflects
2093 // the sum of value sent from payer (final_value_msat) and routing fees
2094 // for the last node in the RouteHint. We need to just add the fees to
2095 // route through the current node so that the preceding node (next iteration)
2097 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
2098 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
2099 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
2101 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
2102 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
2103 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
2104 .checked_add(hop_htlc_minimum_msat_inc);
2105 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
2107 if idx == route.0.len() - 1 {
2108 // The last hop in this iterator is the first hop in
2109 // overall RouteHint.
2110 // If this hop connects to a node with which we have a direct channel,
2111 // ignore the network graph and, if the last hop was added, add our
2112 // direct channel to the candidate set.
2114 // Note that we *must* check if the last hop was added as `add_entry`
2115 // always assumes that the third argument is a node to which we have a
2117 if let Some(first_channels) = first_hop_targets.get_mut(&NodeId::from_pubkey(&hop.src_node_id)) {
2118 sort_first_hop_channels(first_channels, &used_liquidities,
2119 recommended_value_msat, our_node_pubkey);
2120 for details in first_channels {
2121 let first_hop_candidate = CandidateRouteHop::FirstHop { details };
2122 add_entry!(first_hop_candidate, our_node_id,
2123 NodeId::from_pubkey(&hop.src_node_id),
2124 aggregate_next_hops_fee_msat,
2125 aggregate_path_contribution_msat,
2126 aggregate_next_hops_path_htlc_minimum_msat,
2127 aggregate_next_hops_path_penalty_msat,
2128 aggregate_next_hops_cltv_delta,
2129 aggregate_next_hops_path_length);
2137 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
2139 // At this point, targets are filled with the data from first and
2140 // last hops communicated by the caller, and the payment receiver.
2141 let mut found_new_path = false;
2144 // If this loop terminates due the exhaustion of targets, two situations are possible:
2145 // - not enough outgoing liquidity:
2146 // 0 < already_collected_value_msat < final_value_msat
2147 // - enough outgoing liquidity:
2148 // final_value_msat <= already_collected_value_msat < recommended_value_msat
2149 // Both these cases (and other cases except reaching recommended_value_msat) mean that
2150 // paths_collection will be stopped because found_new_path==false.
2151 // This is not necessarily a routing failure.
2152 '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() {
2154 // Since we're going payee-to-payer, hitting our node as a target means we should stop
2155 // traversing the graph and arrange the path out of what we found.
2156 if node_id == our_node_id {
2157 let mut new_entry = dist.remove(&our_node_id).unwrap();
2158 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
2161 let mut features_set = false;
2162 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
2163 for details in first_channels {
2164 if let Some(scid) = ordered_hops.last().unwrap().0.candidate.short_channel_id() {
2165 if details.get_outbound_payment_scid().unwrap() == scid {
2166 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
2167 features_set = true;
2174 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
2175 if let Some(node_info) = node.announcement_info.as_ref() {
2176 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
2178 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
2181 // We can fill in features for everything except hops which were
2182 // provided via the invoice we're paying. We could guess based on the
2183 // recipient's features but for now we simply avoid guessing at all.
2187 // Means we succesfully traversed from the payer to the payee, now
2188 // save this path for the payment route. Also, update the liquidity
2189 // remaining on the used hops, so that we take them into account
2190 // while looking for more paths.
2191 if ordered_hops.last().unwrap().0.node_id == maybe_dummy_payee_node_id {
2195 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
2196 Some(payment_hop) => payment_hop,
2197 // We can't arrive at None because, if we ever add an entry to targets,
2198 // we also fill in the entry in dist (see add_entry!).
2199 None => unreachable!(),
2201 // We "propagate" the fees one hop backward (topologically) here,
2202 // so that fees paid for a HTLC forwarding on the current channel are
2203 // associated with the previous channel (where they will be subtracted).
2204 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
2205 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
2207 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
2208 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
2210 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
2211 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
2213 let mut payment_path = PaymentPath {hops: ordered_hops};
2215 // We could have possibly constructed a slightly inconsistent path: since we reduce
2216 // value being transferred along the way, we could have violated htlc_minimum_msat
2217 // on some channels we already passed (assuming dest->source direction). Here, we
2218 // recompute the fees again, so that if that's the case, we match the currently
2219 // underpaid htlc_minimum_msat with fees.
2220 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
2221 value_contribution_msat = cmp::min(value_contribution_msat, final_value_msat);
2222 payment_path.update_value_and_recompute_fees(value_contribution_msat);
2224 // Since a path allows to transfer as much value as
2225 // the smallest channel it has ("bottleneck"), we should recompute
2226 // the fees so sender HTLC don't overpay fees when traversing
2227 // larger channels than the bottleneck. This may happen because
2228 // when we were selecting those channels we were not aware how much value
2229 // this path will transfer, and the relative fee for them
2230 // might have been computed considering a larger value.
2231 // Remember that we used these channels so that we don't rely
2232 // on the same liquidity in future paths.
2233 let mut prevented_redundant_path_selection = false;
2234 let prev_hop_iter = core::iter::once(&our_node_id)
2235 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
2236 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
2237 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
2238 let used_liquidity_msat = used_liquidities
2239 .entry(hop.candidate.id(*prev_hop < hop.node_id))
2240 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
2241 .or_insert(spent_on_hop_msat);
2242 let hop_capacity = hop.candidate.effective_capacity();
2243 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
2244 if *used_liquidity_msat == hop_max_msat {
2245 // If this path used all of this channel's available liquidity, we know
2246 // this path will not be selected again in the next loop iteration.
2247 prevented_redundant_path_selection = true;
2249 debug_assert!(*used_liquidity_msat <= hop_max_msat);
2251 if !prevented_redundant_path_selection {
2252 // If we weren't capped by hitting a liquidity limit on a channel in the path,
2253 // we'll probably end up picking the same path again on the next iteration.
2254 // Decrease the available liquidity of a hop in the middle of the path.
2255 let victim_candidate = &payment_path.hops[(payment_path.hops.len()) / 2].0.candidate;
2256 let exhausted = u64::max_value();
2257 log_trace!(logger, "Disabling route candidate {} for future path building iterations to
2258 avoid duplicates.", LoggedCandidateHop(victim_candidate));
2259 *used_liquidities.entry(victim_candidate.id(false)).or_default() = exhausted;
2260 *used_liquidities.entry(victim_candidate.id(true)).or_default() = exhausted;
2263 // Track the total amount all our collected paths allow to send so that we know
2264 // when to stop looking for more paths
2265 already_collected_value_msat += value_contribution_msat;
2267 payment_paths.push(payment_path);
2268 found_new_path = true;
2269 break 'path_construction;
2272 // If we found a path back to the payee, we shouldn't try to process it again. This is
2273 // the equivalent of the `elem.was_processed` check in
2274 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
2275 if node_id == maybe_dummy_payee_node_id { continue 'path_construction; }
2277 // Otherwise, since the current target node is not us,
2278 // keep "unrolling" the payment graph from payee to payer by
2279 // finding a way to reach the current target from the payer side.
2280 match network_nodes.get(&node_id) {
2283 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
2284 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
2285 total_cltv_delta, path_length_to_node);
2291 if !found_new_path && channel_saturation_pow_half != 0 {
2292 channel_saturation_pow_half = 0;
2293 continue 'paths_collection;
2295 // If we don't support MPP, no use trying to gather more value ever.
2296 break 'paths_collection;
2300 // Stop either when the recommended value is reached or if no new path was found in this
2302 // In the latter case, making another path finding attempt won't help,
2303 // because we deterministically terminated the search due to low liquidity.
2304 if !found_new_path && channel_saturation_pow_half != 0 {
2305 channel_saturation_pow_half = 0;
2306 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
2307 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
2308 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
2309 break 'paths_collection;
2310 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
2311 // Further, if this was our first walk of the graph, and we weren't limited by an
2312 // htlc_minimum_msat, return immediately because this path should suffice. If we were
2313 // limited by an htlc_minimum_msat value, find another path with a higher value,
2314 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
2315 // still keeping a lower total fee than this path.
2316 if !hit_minimum_limit {
2317 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
2318 break 'paths_collection;
2320 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
2321 path_value_msat = recommended_value_msat;
2326 if payment_paths.len() == 0 {
2327 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2330 if already_collected_value_msat < final_value_msat {
2331 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
2335 let mut selected_route = payment_paths;
2337 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
2338 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
2340 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
2341 // the value they contribute towards the payment amount.
2342 // We sort in descending order as we will remove from the front in `retain`, next.
2343 selected_route.sort_unstable_by(|a, b|
2344 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
2345 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
2348 // We should make sure that at least 1 path left.
2349 let mut paths_left = selected_route.len();
2350 selected_route.retain(|path| {
2351 if paths_left == 1 {
2354 let path_value_msat = path.get_value_msat();
2355 if path_value_msat <= overpaid_value_msat {
2356 overpaid_value_msat -= path_value_msat;
2362 debug_assert!(selected_route.len() > 0);
2364 if overpaid_value_msat != 0 {
2366 // Now, subtract the remaining overpaid value from the most-expensive path.
2367 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
2368 // so that the sender pays less fees overall. And also htlc_minimum_msat.
2369 selected_route.sort_unstable_by(|a, b| {
2370 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2371 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2372 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
2374 let expensive_payment_path = selected_route.first_mut().unwrap();
2376 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
2377 // can't go negative.
2378 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
2379 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
2383 // Sort by the path itself and combine redundant paths.
2384 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
2385 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
2387 selected_route.sort_unstable_by_key(|path| {
2388 let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize];
2389 debug_assert!(path.hops.len() <= key.len());
2390 for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id(true)).zip(key.iter_mut()) {
2395 for idx in 0..(selected_route.len() - 1) {
2396 if idx + 1 >= selected_route.len() { break; }
2397 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)),
2398 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) {
2399 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
2400 selected_route[idx].update_value_and_recompute_fees(new_value);
2401 selected_route.remove(idx + 1);
2405 let mut paths = Vec::new();
2406 for payment_path in selected_route {
2407 let mut hops = Vec::with_capacity(payment_path.hops.len());
2408 for (hop, node_features) in payment_path.hops.iter()
2409 .filter(|(h, _)| h.candidate.short_channel_id().is_some())
2411 hops.push(RouteHop {
2412 pubkey: PublicKey::from_slice(hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
2413 node_features: node_features.clone(),
2414 short_channel_id: hop.candidate.short_channel_id().unwrap(),
2415 channel_features: hop.candidate.features(),
2416 fee_msat: hop.fee_msat,
2417 cltv_expiry_delta: hop.candidate.cltv_expiry_delta(),
2420 let mut final_cltv_delta = final_cltv_expiry_delta;
2421 let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {
2422 if let Some(blinded_path) = h.candidate.blinded_path() {
2423 final_cltv_delta = h.candidate.cltv_expiry_delta();
2425 hops: blinded_path.blinded_hops.clone(),
2426 blinding_point: blinded_path.blinding_point,
2427 excess_final_cltv_expiry_delta: 0,
2428 final_value_msat: h.fee_msat,
2432 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
2433 // applicable for the previous hop.
2434 hops.iter_mut().rev().fold(final_cltv_delta, |prev_cltv_expiry_delta, hop| {
2435 core::mem::replace(&mut hop.cltv_expiry_delta, prev_cltv_expiry_delta)
2438 paths.push(Path { hops, blinded_tail });
2440 // Make sure we would never create a route with more paths than we allow.
2441 debug_assert!(paths.len() <= payment_params.max_path_count.into());
2443 if let Some(node_features) = payment_params.payee.node_features() {
2444 for path in paths.iter_mut() {
2445 path.hops.last_mut().unwrap().node_features = node_features.clone();
2449 let route = Route { paths, payment_params: Some(payment_params.clone()) };
2450 log_info!(logger, "Got route: {}", log_route!(route));
2454 // When an adversarial intermediary node observes a payment, it may be able to infer its
2455 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
2456 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
2457 // payment path by adding a randomized 'shadow route' offset to the final hop.
2458 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
2459 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
2461 let network_channels = network_graph.channels();
2462 let network_nodes = network_graph.nodes();
2464 for path in route.paths.iter_mut() {
2465 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
2467 // Remember the last three nodes of the random walk and avoid looping back on them.
2468 // Init with the last three nodes from the actual path, if possible.
2469 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
2470 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(2)).unwrap().pubkey),
2471 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(3)).unwrap().pubkey)];
2473 // Choose the last publicly known node as the starting point for the random walk.
2474 let mut cur_hop: Option<NodeId> = None;
2475 let mut path_nonce = [0u8; 12];
2476 if let Some(starting_hop) = path.hops.iter().rev()
2477 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
2478 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
2479 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
2482 // Init PRNG with the path-dependant nonce, which is static for private paths.
2483 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
2484 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
2486 // Pick a random path length in [1 .. 3]
2487 prng.process_in_place(&mut random_path_bytes);
2488 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
2490 for random_hop in 0..random_walk_length {
2491 // If we don't find a suitable offset in the public network graph, we default to
2492 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2493 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
2495 if let Some(cur_node_id) = cur_hop {
2496 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
2497 // Randomly choose the next unvisited hop.
2498 prng.process_in_place(&mut random_path_bytes);
2499 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
2500 .checked_rem(cur_node.channels.len())
2501 .and_then(|index| cur_node.channels.get(index))
2502 .and_then(|id| network_channels.get(id)) {
2503 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
2504 if !nodes_to_avoid.iter().any(|x| x == next_id) {
2505 nodes_to_avoid[random_hop] = *next_id;
2506 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
2507 cur_hop = Some(*next_id);
2514 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
2515 .checked_add(random_hop_offset)
2516 .unwrap_or(shadow_ctlv_expiry_delta_offset);
2519 // Limit the total offset to reduce the worst-case locked liquidity timevalue
2520 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
2521 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
2523 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
2524 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2525 let path_total_cltv_expiry_delta: u32 = path.hops.iter().map(|h| h.cltv_expiry_delta).sum();
2526 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
2527 max_path_offset = cmp::max(
2528 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
2529 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
2530 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
2532 // Add 'shadow' CLTV offset to the final hop
2533 if let Some(tail) = path.blinded_tail.as_mut() {
2534 tail.excess_final_cltv_expiry_delta = tail.excess_final_cltv_expiry_delta
2535 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(tail.excess_final_cltv_expiry_delta);
2537 if let Some(last_hop) = path.hops.last_mut() {
2538 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
2539 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
2544 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
2545 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
2547 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
2548 pub fn build_route_from_hops<L: Deref, GL: Deref>(
2549 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
2550 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
2551 ) -> Result<Route, LightningError>
2552 where L::Target: Logger, GL::Target: Logger {
2553 let graph_lock = network_graph.read_only();
2554 let mut route = build_route_from_hops_internal(
2555 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
2556 route_params.final_value_msat, logger, random_seed_bytes)?;
2557 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
2561 fn build_route_from_hops_internal<L: Deref>(
2562 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
2563 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, logger: L,
2564 random_seed_bytes: &[u8; 32]
2565 ) -> Result<Route, LightningError> where L::Target: Logger {
2568 our_node_id: NodeId,
2569 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
2572 impl Score for HopScorer {
2573 type ScoreParams = ();
2574 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
2575 _usage: ChannelUsage, _score_params: &Self::ScoreParams) -> u64
2577 let mut cur_id = self.our_node_id;
2578 for i in 0..self.hop_ids.len() {
2579 if let Some(next_id) = self.hop_ids[i] {
2580 if cur_id == *source && next_id == *target {
2591 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2593 fn payment_path_successful(&mut self, _path: &Path) {}
2595 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2597 fn probe_successful(&mut self, _path: &Path) {}
2600 impl<'a> Writeable for HopScorer {
2602 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
2607 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
2608 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
2611 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
2612 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
2613 for i in 0..hops.len() {
2614 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
2617 let scorer = HopScorer { our_node_id, hop_ids };
2619 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
2620 logger, &scorer, &(), random_seed_bytes)
2625 use crate::blinded_path::{BlindedHop, BlindedPath};
2626 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
2627 use crate::routing::utxo::UtxoResult;
2628 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
2629 BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
2630 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
2631 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
2632 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
2633 use crate::chain::transaction::OutPoint;
2634 use crate::sign::EntropySource;
2635 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, ChannelFeatures, InitFeatures, NodeFeatures};
2636 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
2637 use crate::ln::channelmanager;
2638 use crate::offers::invoice::BlindedPayInfo;
2639 use crate::util::config::UserConfig;
2640 use crate::util::test_utils as ln_test_utils;
2641 use crate::util::chacha20::ChaCha20;
2642 use crate::util::ser::{Readable, Writeable};
2644 use crate::util::ser::Writer;
2646 use bitcoin::hashes::Hash;
2647 use bitcoin::network::constants::Network;
2648 use bitcoin::blockdata::constants::genesis_block;
2649 use bitcoin::blockdata::script::Builder;
2650 use bitcoin::blockdata::opcodes;
2651 use bitcoin::blockdata::transaction::TxOut;
2655 use bitcoin::secp256k1::{PublicKey,SecretKey};
2656 use bitcoin::secp256k1::Secp256k1;
2658 use crate::io::Cursor;
2659 use crate::prelude::*;
2660 use crate::sync::Arc;
2662 use core::convert::TryInto;
2664 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
2665 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
2666 channelmanager::ChannelDetails {
2667 channel_id: [0; 32],
2668 counterparty: channelmanager::ChannelCounterparty {
2671 unspendable_punishment_reserve: 0,
2672 forwarding_info: None,
2673 outbound_htlc_minimum_msat: None,
2674 outbound_htlc_maximum_msat: None,
2676 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2679 outbound_scid_alias: None,
2680 inbound_scid_alias: None,
2681 channel_value_satoshis: 0,
2684 outbound_capacity_msat,
2685 next_outbound_htlc_limit_msat: outbound_capacity_msat,
2686 next_outbound_htlc_minimum_msat: 0,
2687 inbound_capacity_msat: 42,
2688 unspendable_punishment_reserve: None,
2689 confirmations_required: None,
2690 confirmations: None,
2691 force_close_spend_delay: None,
2692 is_outbound: true, is_channel_ready: true,
2693 is_usable: true, is_public: true,
2694 inbound_htlc_minimum_msat: None,
2695 inbound_htlc_maximum_msat: None,
2697 feerate_sat_per_1000_weight: None,
2698 channel_shutdown_state: Some(channelmanager::ChannelShutdownState::NotShuttingDown),
2703 fn simple_route_test() {
2704 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2705 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2706 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2707 let scorer = ln_test_utils::TestScorer::new();
2708 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2709 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2711 // Simple route to 2 via 1
2713 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) {
2714 assert_eq!(err, "Cannot send a payment of 0 msat");
2715 } else { panic!(); }
2717 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2718 assert_eq!(route.paths[0].hops.len(), 2);
2720 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2721 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2722 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
2723 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2724 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2725 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2727 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2728 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2729 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2730 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2731 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2732 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2736 fn invalid_first_hop_test() {
2737 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2738 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2739 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2740 let scorer = ln_test_utils::TestScorer::new();
2741 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2742 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2744 // Simple route to 2 via 1
2746 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2748 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2749 get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
2750 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2751 } else { panic!(); }
2753 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2754 assert_eq!(route.paths[0].hops.len(), 2);
2758 fn htlc_minimum_test() {
2759 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2760 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2761 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2762 let scorer = ln_test_utils::TestScorer::new();
2763 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2764 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2766 // Simple route to 2 via 1
2768 // Disable other paths
2769 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2770 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2771 short_channel_id: 12,
2773 flags: 2, // to disable
2774 cltv_expiry_delta: 0,
2775 htlc_minimum_msat: 0,
2776 htlc_maximum_msat: MAX_VALUE_MSAT,
2778 fee_proportional_millionths: 0,
2779 excess_data: Vec::new()
2781 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2782 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2783 short_channel_id: 3,
2785 flags: 2, // to disable
2786 cltv_expiry_delta: 0,
2787 htlc_minimum_msat: 0,
2788 htlc_maximum_msat: MAX_VALUE_MSAT,
2790 fee_proportional_millionths: 0,
2791 excess_data: Vec::new()
2793 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2794 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2795 short_channel_id: 13,
2797 flags: 2, // to disable
2798 cltv_expiry_delta: 0,
2799 htlc_minimum_msat: 0,
2800 htlc_maximum_msat: MAX_VALUE_MSAT,
2802 fee_proportional_millionths: 0,
2803 excess_data: Vec::new()
2805 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2806 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2807 short_channel_id: 6,
2809 flags: 2, // to disable
2810 cltv_expiry_delta: 0,
2811 htlc_minimum_msat: 0,
2812 htlc_maximum_msat: MAX_VALUE_MSAT,
2814 fee_proportional_millionths: 0,
2815 excess_data: Vec::new()
2817 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2818 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2819 short_channel_id: 7,
2821 flags: 2, // to disable
2822 cltv_expiry_delta: 0,
2823 htlc_minimum_msat: 0,
2824 htlc_maximum_msat: MAX_VALUE_MSAT,
2826 fee_proportional_millionths: 0,
2827 excess_data: Vec::new()
2830 // Check against amount_to_transfer_over_msat.
2831 // Set minimal HTLC of 200_000_000 msat.
2832 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2833 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2834 short_channel_id: 2,
2837 cltv_expiry_delta: 0,
2838 htlc_minimum_msat: 200_000_000,
2839 htlc_maximum_msat: MAX_VALUE_MSAT,
2841 fee_proportional_millionths: 0,
2842 excess_data: Vec::new()
2845 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2847 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2848 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2849 short_channel_id: 4,
2852 cltv_expiry_delta: 0,
2853 htlc_minimum_msat: 0,
2854 htlc_maximum_msat: 199_999_999,
2856 fee_proportional_millionths: 0,
2857 excess_data: Vec::new()
2860 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2861 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) {
2862 assert_eq!(err, "Failed to find a path to the given destination");
2863 } else { panic!(); }
2865 // Lift the restriction on the first hop.
2866 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2867 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2868 short_channel_id: 2,
2871 cltv_expiry_delta: 0,
2872 htlc_minimum_msat: 0,
2873 htlc_maximum_msat: MAX_VALUE_MSAT,
2875 fee_proportional_millionths: 0,
2876 excess_data: Vec::new()
2879 // A payment above the minimum should pass
2880 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2881 assert_eq!(route.paths[0].hops.len(), 2);
2885 fn htlc_minimum_overpay_test() {
2886 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2887 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2888 let config = UserConfig::default();
2889 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
2890 let scorer = ln_test_utils::TestScorer::new();
2891 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2892 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2894 // A route to node#2 via two paths.
2895 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2896 // Thus, they can't send 60 without overpaying.
2897 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2898 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2899 short_channel_id: 2,
2902 cltv_expiry_delta: 0,
2903 htlc_minimum_msat: 35_000,
2904 htlc_maximum_msat: 40_000,
2906 fee_proportional_millionths: 0,
2907 excess_data: Vec::new()
2909 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2910 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2911 short_channel_id: 12,
2914 cltv_expiry_delta: 0,
2915 htlc_minimum_msat: 35_000,
2916 htlc_maximum_msat: 40_000,
2918 fee_proportional_millionths: 0,
2919 excess_data: Vec::new()
2923 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2924 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2925 short_channel_id: 13,
2928 cltv_expiry_delta: 0,
2929 htlc_minimum_msat: 0,
2930 htlc_maximum_msat: MAX_VALUE_MSAT,
2932 fee_proportional_millionths: 0,
2933 excess_data: Vec::new()
2935 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2936 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2937 short_channel_id: 4,
2940 cltv_expiry_delta: 0,
2941 htlc_minimum_msat: 0,
2942 htlc_maximum_msat: MAX_VALUE_MSAT,
2944 fee_proportional_millionths: 0,
2945 excess_data: Vec::new()
2948 // Disable other paths
2949 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2950 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2951 short_channel_id: 1,
2953 flags: 2, // to disable
2954 cltv_expiry_delta: 0,
2955 htlc_minimum_msat: 0,
2956 htlc_maximum_msat: MAX_VALUE_MSAT,
2958 fee_proportional_millionths: 0,
2959 excess_data: Vec::new()
2962 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
2963 // Overpay fees to hit htlc_minimum_msat.
2964 let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
2965 // TODO: this could be better balanced to overpay 10k and not 15k.
2966 assert_eq!(overpaid_fees, 15_000);
2968 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2969 // while taking even more fee to match htlc_minimum_msat.
2970 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2971 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2972 short_channel_id: 12,
2975 cltv_expiry_delta: 0,
2976 htlc_minimum_msat: 65_000,
2977 htlc_maximum_msat: 80_000,
2979 fee_proportional_millionths: 0,
2980 excess_data: Vec::new()
2982 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2983 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2984 short_channel_id: 2,
2987 cltv_expiry_delta: 0,
2988 htlc_minimum_msat: 0,
2989 htlc_maximum_msat: MAX_VALUE_MSAT,
2991 fee_proportional_millionths: 0,
2992 excess_data: Vec::new()
2994 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2996 short_channel_id: 4,
2999 cltv_expiry_delta: 0,
3000 htlc_minimum_msat: 0,
3001 htlc_maximum_msat: MAX_VALUE_MSAT,
3003 fee_proportional_millionths: 100_000,
3004 excess_data: Vec::new()
3007 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3008 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
3009 assert_eq!(route.paths.len(), 1);
3010 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
3011 let fees = route.paths[0].hops[0].fee_msat;
3012 assert_eq!(fees, 5_000);
3014 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3015 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
3016 // the other channel.
3017 assert_eq!(route.paths.len(), 1);
3018 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3019 let fees = route.paths[0].hops[0].fee_msat;
3020 assert_eq!(fees, 5_000);
3024 fn disable_channels_test() {
3025 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3026 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3027 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3028 let scorer = ln_test_utils::TestScorer::new();
3029 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3030 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3032 // // Disable channels 4 and 12 by flags=2
3033 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3034 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3035 short_channel_id: 4,
3037 flags: 2, // to disable
3038 cltv_expiry_delta: 0,
3039 htlc_minimum_msat: 0,
3040 htlc_maximum_msat: MAX_VALUE_MSAT,
3042 fee_proportional_millionths: 0,
3043 excess_data: Vec::new()
3045 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3046 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3047 short_channel_id: 12,
3049 flags: 2, // to disable
3050 cltv_expiry_delta: 0,
3051 htlc_minimum_msat: 0,
3052 htlc_maximum_msat: MAX_VALUE_MSAT,
3054 fee_proportional_millionths: 0,
3055 excess_data: Vec::new()
3058 // If all the channels require some features we don't understand, route should fail
3059 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) {
3060 assert_eq!(err, "Failed to find a path to the given destination");
3061 } else { panic!(); }
3063 // If we specify a channel to node7, that overrides our local channel view and that gets used
3064 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3065 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();
3066 assert_eq!(route.paths[0].hops.len(), 2);
3068 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3069 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3070 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3071 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3072 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
3073 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3075 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3076 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3077 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3078 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3079 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3080 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3084 fn disable_node_test() {
3085 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3086 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3087 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3088 let scorer = ln_test_utils::TestScorer::new();
3089 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3090 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3092 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
3093 let mut unknown_features = NodeFeatures::empty();
3094 unknown_features.set_unknown_feature_required();
3095 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
3096 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
3097 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
3099 // If all nodes require some features we don't understand, route should fail
3100 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) {
3101 assert_eq!(err, "Failed to find a path to the given destination");
3102 } else { panic!(); }
3104 // If we specify a channel to node7, that overrides our local channel view and that gets used
3105 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3106 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();
3107 assert_eq!(route.paths[0].hops.len(), 2);
3109 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3110 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3111 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3112 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3113 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
3114 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3116 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3117 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3118 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3119 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3120 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3121 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3123 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
3124 // naively) assume that the user checked the feature bits on the invoice, which override
3125 // the node_announcement.
3129 fn our_chans_test() {
3130 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3131 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3132 let scorer = ln_test_utils::TestScorer::new();
3133 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3134 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3136 // Route to 1 via 2 and 3 because our channel to 1 is disabled
3137 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
3138 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3139 assert_eq!(route.paths[0].hops.len(), 3);
3141 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3142 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3143 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3144 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3145 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3146 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3148 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3149 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3150 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3151 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (3 << 4) | 2);
3152 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3153 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3155 assert_eq!(route.paths[0].hops[2].pubkey, nodes[0]);
3156 assert_eq!(route.paths[0].hops[2].short_channel_id, 3);
3157 assert_eq!(route.paths[0].hops[2].fee_msat, 100);
3158 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
3159 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(1));
3160 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(3));
3162 // If we specify a channel to node7, that overrides our local channel view and that gets used
3163 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3164 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3165 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();
3166 assert_eq!(route.paths[0].hops.len(), 2);
3168 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
3169 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3170 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3171 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
3172 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3173 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3175 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3176 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
3177 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3178 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3179 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3180 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
3183 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3184 let zero_fees = RoutingFees {
3186 proportional_millionths: 0,
3188 vec![RouteHint(vec![RouteHintHop {
3189 src_node_id: nodes[3],
3190 short_channel_id: 8,
3192 cltv_expiry_delta: (8 << 4) | 1,
3193 htlc_minimum_msat: None,
3194 htlc_maximum_msat: None,
3196 ]), RouteHint(vec![RouteHintHop {
3197 src_node_id: nodes[4],
3198 short_channel_id: 9,
3201 proportional_millionths: 0,
3203 cltv_expiry_delta: (9 << 4) | 1,
3204 htlc_minimum_msat: None,
3205 htlc_maximum_msat: None,
3206 }]), RouteHint(vec![RouteHintHop {
3207 src_node_id: nodes[5],
3208 short_channel_id: 10,
3210 cltv_expiry_delta: (10 << 4) | 1,
3211 htlc_minimum_msat: None,
3212 htlc_maximum_msat: None,
3216 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3217 let zero_fees = RoutingFees {
3219 proportional_millionths: 0,
3221 vec![RouteHint(vec![RouteHintHop {
3222 src_node_id: nodes[2],
3223 short_channel_id: 5,
3226 proportional_millionths: 0,
3228 cltv_expiry_delta: (5 << 4) | 1,
3229 htlc_minimum_msat: None,
3230 htlc_maximum_msat: None,
3232 src_node_id: nodes[3],
3233 short_channel_id: 8,
3235 cltv_expiry_delta: (8 << 4) | 1,
3236 htlc_minimum_msat: None,
3237 htlc_maximum_msat: None,
3239 ]), RouteHint(vec![RouteHintHop {
3240 src_node_id: nodes[4],
3241 short_channel_id: 9,
3244 proportional_millionths: 0,
3246 cltv_expiry_delta: (9 << 4) | 1,
3247 htlc_minimum_msat: None,
3248 htlc_maximum_msat: None,
3249 }]), RouteHint(vec![RouteHintHop {
3250 src_node_id: nodes[5],
3251 short_channel_id: 10,
3253 cltv_expiry_delta: (10 << 4) | 1,
3254 htlc_minimum_msat: None,
3255 htlc_maximum_msat: None,
3260 fn partial_route_hint_test() {
3261 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3262 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3263 let scorer = ln_test_utils::TestScorer::new();
3264 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3265 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3267 // Simple test across 2, 3, 5, and 4 via a last_hop channel
3268 // Tests the behaviour when the RouteHint contains a suboptimal hop.
3269 // RouteHint may be partially used by the algo to build the best path.
3271 // First check that last hop can't have its source as the payee.
3272 let invalid_last_hop = RouteHint(vec![RouteHintHop {
3273 src_node_id: nodes[6],
3274 short_channel_id: 8,
3277 proportional_millionths: 0,
3279 cltv_expiry_delta: (8 << 4) | 1,
3280 htlc_minimum_msat: None,
3281 htlc_maximum_msat: None,
3284 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
3285 invalid_last_hops.push(invalid_last_hop);
3287 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops).unwrap();
3288 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) {
3289 assert_eq!(err, "Route hint cannot have the payee as the source.");
3290 } else { panic!(); }
3293 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes)).unwrap();
3294 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3295 assert_eq!(route.paths[0].hops.len(), 5);
3297 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3298 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3299 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3300 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3301 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3302 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3304 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3305 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3306 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3307 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3308 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3309 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3311 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3312 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3313 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3314 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3315 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3316 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3318 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3319 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3320 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3321 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3322 // If we have a peer in the node map, we'll use their features here since we don't have
3323 // a way of figuring out their features from the invoice:
3324 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3325 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3327 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3328 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3329 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3330 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3331 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3332 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3335 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3336 let zero_fees = RoutingFees {
3338 proportional_millionths: 0,
3340 vec![RouteHint(vec![RouteHintHop {
3341 src_node_id: nodes[3],
3342 short_channel_id: 8,
3344 cltv_expiry_delta: (8 << 4) | 1,
3345 htlc_minimum_msat: None,
3346 htlc_maximum_msat: None,
3347 }]), RouteHint(vec![
3349 ]), RouteHint(vec![RouteHintHop {
3350 src_node_id: nodes[5],
3351 short_channel_id: 10,
3353 cltv_expiry_delta: (10 << 4) | 1,
3354 htlc_minimum_msat: None,
3355 htlc_maximum_msat: None,
3360 fn ignores_empty_last_hops_test() {
3361 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3362 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3363 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes)).unwrap();
3364 let scorer = ln_test_utils::TestScorer::new();
3365 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3366 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3368 // Test handling of an empty RouteHint passed in Invoice.
3370 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3371 assert_eq!(route.paths[0].hops.len(), 5);
3373 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3374 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3375 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3376 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3377 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3378 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3380 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3381 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3382 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3383 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3384 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3385 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3387 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3388 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3389 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3390 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3391 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3392 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3394 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3395 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3396 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3397 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3398 // If we have a peer in the node map, we'll use their features here since we don't have
3399 // a way of figuring out their features from the invoice:
3400 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3401 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3403 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3404 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3405 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3406 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3407 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3408 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3411 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3413 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3414 let zero_fees = RoutingFees {
3416 proportional_millionths: 0,
3418 vec![RouteHint(vec![RouteHintHop {
3419 src_node_id: hint_hops[0],
3420 short_channel_id: 0xff00,
3423 proportional_millionths: 0,
3425 cltv_expiry_delta: (5 << 4) | 1,
3426 htlc_minimum_msat: None,
3427 htlc_maximum_msat: None,
3429 src_node_id: hint_hops[1],
3430 short_channel_id: 0xff01,
3432 cltv_expiry_delta: (8 << 4) | 1,
3433 htlc_minimum_msat: None,
3434 htlc_maximum_msat: None,
3439 fn multi_hint_last_hops_test() {
3440 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3441 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3442 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3443 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3444 let scorer = ln_test_utils::TestScorer::new();
3445 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3446 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3447 // Test through channels 2, 3, 0xff00, 0xff01.
3448 // Test shows that multiple hop hints are considered.
3450 // Disabling channels 6 & 7 by flags=2
3451 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3452 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3453 short_channel_id: 6,
3455 flags: 2, // to disable
3456 cltv_expiry_delta: 0,
3457 htlc_minimum_msat: 0,
3458 htlc_maximum_msat: MAX_VALUE_MSAT,
3460 fee_proportional_millionths: 0,
3461 excess_data: Vec::new()
3463 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3464 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3465 short_channel_id: 7,
3467 flags: 2, // to disable
3468 cltv_expiry_delta: 0,
3469 htlc_minimum_msat: 0,
3470 htlc_maximum_msat: MAX_VALUE_MSAT,
3472 fee_proportional_millionths: 0,
3473 excess_data: Vec::new()
3476 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3477 assert_eq!(route.paths[0].hops.len(), 4);
3479 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3480 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3481 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3482 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3483 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3484 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3486 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3487 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3488 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3489 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3490 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3491 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3493 assert_eq!(route.paths[0].hops[2].pubkey, nodes[3]);
3494 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3495 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3496 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3497 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(4));
3498 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3500 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3501 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3502 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3503 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3504 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3505 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3509 fn private_multi_hint_last_hops_test() {
3510 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3511 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3513 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3514 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3516 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3517 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3518 let scorer = ln_test_utils::TestScorer::new();
3519 // Test through channels 2, 3, 0xff00, 0xff01.
3520 // Test shows that multiple hop hints are considered.
3522 // Disabling channels 6 & 7 by flags=2
3523 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3524 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3525 short_channel_id: 6,
3527 flags: 2, // to disable
3528 cltv_expiry_delta: 0,
3529 htlc_minimum_msat: 0,
3530 htlc_maximum_msat: MAX_VALUE_MSAT,
3532 fee_proportional_millionths: 0,
3533 excess_data: Vec::new()
3535 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3536 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3537 short_channel_id: 7,
3539 flags: 2, // to disable
3540 cltv_expiry_delta: 0,
3541 htlc_minimum_msat: 0,
3542 htlc_maximum_msat: MAX_VALUE_MSAT,
3544 fee_proportional_millionths: 0,
3545 excess_data: Vec::new()
3548 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &[42u8; 32]).unwrap();
3549 assert_eq!(route.paths[0].hops.len(), 4);
3551 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3552 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3553 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3554 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3555 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3556 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3558 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3559 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3560 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3561 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3562 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3563 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3565 assert_eq!(route.paths[0].hops[2].pubkey, non_announced_pubkey);
3566 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3567 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3568 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3569 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3570 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3572 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3573 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3574 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3575 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3576 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3577 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3580 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3581 let zero_fees = RoutingFees {
3583 proportional_millionths: 0,
3585 vec![RouteHint(vec![RouteHintHop {
3586 src_node_id: nodes[4],
3587 short_channel_id: 11,
3589 cltv_expiry_delta: (11 << 4) | 1,
3590 htlc_minimum_msat: None,
3591 htlc_maximum_msat: None,
3593 src_node_id: nodes[3],
3594 short_channel_id: 8,
3596 cltv_expiry_delta: (8 << 4) | 1,
3597 htlc_minimum_msat: None,
3598 htlc_maximum_msat: None,
3599 }]), RouteHint(vec![RouteHintHop {
3600 src_node_id: nodes[4],
3601 short_channel_id: 9,
3604 proportional_millionths: 0,
3606 cltv_expiry_delta: (9 << 4) | 1,
3607 htlc_minimum_msat: None,
3608 htlc_maximum_msat: None,
3609 }]), RouteHint(vec![RouteHintHop {
3610 src_node_id: nodes[5],
3611 short_channel_id: 10,
3613 cltv_expiry_delta: (10 << 4) | 1,
3614 htlc_minimum_msat: None,
3615 htlc_maximum_msat: None,
3620 fn last_hops_with_public_channel_test() {
3621 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3622 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3623 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes)).unwrap();
3624 let scorer = ln_test_utils::TestScorer::new();
3625 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3626 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3627 // This test shows that public routes can be present in the invoice
3628 // which would be handled in the same manner.
3630 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3631 assert_eq!(route.paths[0].hops.len(), 5);
3633 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3634 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3635 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3636 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3637 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3638 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3640 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3641 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3642 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3643 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3644 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3645 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3647 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3648 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3649 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3650 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3651 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3652 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3654 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3655 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3656 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3657 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3658 // If we have a peer in the node map, we'll use their features here since we don't have
3659 // a way of figuring out their features from the invoice:
3660 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3661 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3663 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3664 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3665 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3666 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3667 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3668 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3672 fn our_chans_last_hop_connect_test() {
3673 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3674 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3675 let scorer = ln_test_utils::TestScorer::new();
3676 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3677 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3679 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3680 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3681 let mut last_hops = last_hops(&nodes);
3682 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone()).unwrap();
3683 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();
3684 assert_eq!(route.paths[0].hops.len(), 2);
3686 assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
3687 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3688 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
3689 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3690 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3691 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3693 assert_eq!(route.paths[0].hops[1].pubkey, nodes[6]);
3694 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3695 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3696 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3697 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3698 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3700 last_hops[0].0[0].fees.base_msat = 1000;
3702 // Revert to via 6 as the fee on 8 goes up
3703 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops).unwrap();
3704 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3705 assert_eq!(route.paths[0].hops.len(), 4);
3707 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3708 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3709 assert_eq!(route.paths[0].hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
3710 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3711 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3712 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3714 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3715 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3716 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3717 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (7 << 4) | 1);
3718 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3719 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3721 assert_eq!(route.paths[0].hops[2].pubkey, nodes[5]);
3722 assert_eq!(route.paths[0].hops[2].short_channel_id, 7);
3723 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3724 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (10 << 4) | 1);
3725 // If we have a peer in the node map, we'll use their features here since we don't have
3726 // a way of figuring out their features from the invoice:
3727 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
3728 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(7));
3730 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3731 assert_eq!(route.paths[0].hops[3].short_channel_id, 10);
3732 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3733 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3734 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3735 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3737 // ...but still use 8 for larger payments as 6 has a variable feerate
3738 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
3739 assert_eq!(route.paths[0].hops.len(), 5);
3741 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3742 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3743 assert_eq!(route.paths[0].hops[0].fee_msat, 3000);
3744 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3745 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3746 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3748 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3749 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3750 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3751 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3752 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3753 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3755 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3756 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3757 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3758 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3759 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3760 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3762 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3763 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3764 assert_eq!(route.paths[0].hops[3].fee_msat, 1000);
3765 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3766 // If we have a peer in the node map, we'll use their features here since we don't have
3767 // a way of figuring out their features from the invoice:
3768 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3769 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3771 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3772 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3773 assert_eq!(route.paths[0].hops[4].fee_msat, 2000);
3774 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3775 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3776 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3779 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> {
3780 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3781 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3782 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3784 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3785 let last_hops = RouteHint(vec![RouteHintHop {
3786 src_node_id: middle_node_id,
3787 short_channel_id: 8,
3790 proportional_millionths: last_hop_fee_prop,
3792 cltv_expiry_delta: (8 << 4) | 1,
3793 htlc_minimum_msat: None,
3794 htlc_maximum_msat: last_hop_htlc_max,
3796 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]).unwrap();
3797 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3798 let scorer = ln_test_utils::TestScorer::new();
3799 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3800 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3801 let logger = ln_test_utils::TestLogger::new();
3802 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
3803 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3804 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, &logger, &scorer, &(), &random_seed_bytes);
3809 fn unannounced_path_test() {
3810 // We should be able to send a payment to a destination without any help of a routing graph
3811 // if we have a channel with a common counterparty that appears in the first and last hop
3813 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3815 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3816 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3817 assert_eq!(route.paths[0].hops.len(), 2);
3819 assert_eq!(route.paths[0].hops[0].pubkey, middle_node_id);
3820 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3821 assert_eq!(route.paths[0].hops[0].fee_msat, 1001);
3822 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3823 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &[0b11]);
3824 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3826 assert_eq!(route.paths[0].hops[1].pubkey, target_node_id);
3827 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3828 assert_eq!(route.paths[0].hops[1].fee_msat, 1000000);
3829 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3830 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3831 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3835 fn overflow_unannounced_path_test_liquidity_underflow() {
3836 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3837 // the last-hop had a fee which overflowed a u64, we'd panic.
3838 // This was due to us adding the first-hop from us unconditionally, causing us to think
3839 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3840 // In this test, we previously hit a subtraction underflow due to having less available
3841 // liquidity at the last hop than 0.
3842 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());
3846 fn overflow_unannounced_path_test_feerate_overflow() {
3847 // This tests for the same case as above, except instead of hitting a subtraction
3848 // underflow, we hit a case where the fee charged at a hop overflowed.
3849 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());
3853 fn available_amount_while_routing_test() {
3854 // Tests whether we choose the correct available channel amount while routing.
3856 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3857 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3858 let scorer = ln_test_utils::TestScorer::new();
3859 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3860 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3861 let config = UserConfig::default();
3862 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
3864 // We will use a simple single-path route from
3865 // our node to node2 via node0: channels {1, 3}.
3867 // First disable all other paths.
3868 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3869 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3870 short_channel_id: 2,
3873 cltv_expiry_delta: 0,
3874 htlc_minimum_msat: 0,
3875 htlc_maximum_msat: 100_000,
3877 fee_proportional_millionths: 0,
3878 excess_data: Vec::new()
3880 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3881 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3882 short_channel_id: 12,
3885 cltv_expiry_delta: 0,
3886 htlc_minimum_msat: 0,
3887 htlc_maximum_msat: 100_000,
3889 fee_proportional_millionths: 0,
3890 excess_data: Vec::new()
3893 // Make the first channel (#1) very permissive,
3894 // and we will be testing all limits on the second channel.
3895 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3896 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3897 short_channel_id: 1,
3900 cltv_expiry_delta: 0,
3901 htlc_minimum_msat: 0,
3902 htlc_maximum_msat: 1_000_000_000,
3904 fee_proportional_millionths: 0,
3905 excess_data: Vec::new()
3908 // First, let's see if routing works if we have absolutely no idea about the available amount.
3909 // In this case, it should be set to 250_000 sats.
3910 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3911 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3912 short_channel_id: 3,
3915 cltv_expiry_delta: 0,
3916 htlc_minimum_msat: 0,
3917 htlc_maximum_msat: 250_000_000,
3919 fee_proportional_millionths: 0,
3920 excess_data: Vec::new()
3924 // Attempt to route more than available results in a failure.
3925 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3926 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3927 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3928 } else { panic!(); }
3932 // Now, attempt to route an exact amount we have should be fine.
3933 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, Arc::clone(&logger), &scorer, &(),&random_seed_bytes).unwrap();
3934 assert_eq!(route.paths.len(), 1);
3935 let path = route.paths.last().unwrap();
3936 assert_eq!(path.hops.len(), 2);
3937 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3938 assert_eq!(path.final_value_msat(), 250_000_000);
3941 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3942 // Disable channel #1 and use another first hop.
3943 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3944 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3945 short_channel_id: 1,
3948 cltv_expiry_delta: 0,
3949 htlc_minimum_msat: 0,
3950 htlc_maximum_msat: 1_000_000_000,
3952 fee_proportional_millionths: 0,
3953 excess_data: Vec::new()
3956 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3957 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3960 // Attempt to route more than available results in a failure.
3961 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3962 &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
3963 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3964 } else { panic!(); }
3968 // Now, attempt to route an exact amount we have should be fine.
3969 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();
3970 assert_eq!(route.paths.len(), 1);
3971 let path = route.paths.last().unwrap();
3972 assert_eq!(path.hops.len(), 2);
3973 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3974 assert_eq!(path.final_value_msat(), 200_000_000);
3977 // Enable channel #1 back.
3978 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3979 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3980 short_channel_id: 1,
3983 cltv_expiry_delta: 0,
3984 htlc_minimum_msat: 0,
3985 htlc_maximum_msat: 1_000_000_000,
3987 fee_proportional_millionths: 0,
3988 excess_data: Vec::new()
3992 // Now let's see if routing works if we know only htlc_maximum_msat.
3993 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3994 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3995 short_channel_id: 3,
3998 cltv_expiry_delta: 0,
3999 htlc_minimum_msat: 0,
4000 htlc_maximum_msat: 15_000,
4002 fee_proportional_millionths: 0,
4003 excess_data: Vec::new()
4007 // Attempt to route more than available results in a failure.
4008 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4009 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4010 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4011 } else { panic!(); }
4015 // Now, attempt to route an exact amount we have should be fine.
4016 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4017 assert_eq!(route.paths.len(), 1);
4018 let path = route.paths.last().unwrap();
4019 assert_eq!(path.hops.len(), 2);
4020 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4021 assert_eq!(path.final_value_msat(), 15_000);
4024 // Now let's see if routing works if we know only capacity from the UTXO.
4026 // We can't change UTXO capacity on the fly, so we'll disable
4027 // the existing channel and add another one with the capacity we need.
4028 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4029 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4030 short_channel_id: 3,
4033 cltv_expiry_delta: 0,
4034 htlc_minimum_msat: 0,
4035 htlc_maximum_msat: MAX_VALUE_MSAT,
4037 fee_proportional_millionths: 0,
4038 excess_data: Vec::new()
4041 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
4042 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
4043 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
4044 .push_opcode(opcodes::all::OP_PUSHNUM_2)
4045 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
4047 *chain_monitor.utxo_ret.lock().unwrap() =
4048 UtxoResult::Sync(Ok(TxOut { value: 15, script_pubkey: good_script.clone() }));
4049 gossip_sync.add_utxo_lookup(Some(chain_monitor));
4051 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
4052 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4053 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4054 short_channel_id: 333,
4057 cltv_expiry_delta: (3 << 4) | 1,
4058 htlc_minimum_msat: 0,
4059 htlc_maximum_msat: 15_000,
4061 fee_proportional_millionths: 0,
4062 excess_data: Vec::new()
4064 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4065 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4066 short_channel_id: 333,
4069 cltv_expiry_delta: (3 << 4) | 2,
4070 htlc_minimum_msat: 0,
4071 htlc_maximum_msat: 15_000,
4073 fee_proportional_millionths: 0,
4074 excess_data: Vec::new()
4078 // Attempt to route more than available results in a failure.
4079 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4080 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4081 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4082 } else { panic!(); }
4086 // Now, attempt to route an exact amount we have should be fine.
4087 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4088 assert_eq!(route.paths.len(), 1);
4089 let path = route.paths.last().unwrap();
4090 assert_eq!(path.hops.len(), 2);
4091 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4092 assert_eq!(path.final_value_msat(), 15_000);
4095 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
4096 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4097 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4098 short_channel_id: 333,
4101 cltv_expiry_delta: 0,
4102 htlc_minimum_msat: 0,
4103 htlc_maximum_msat: 10_000,
4105 fee_proportional_millionths: 0,
4106 excess_data: Vec::new()
4110 // Attempt to route more than available results in a failure.
4111 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4112 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4113 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4114 } else { panic!(); }
4118 // Now, attempt to route an exact amount we have should be fine.
4119 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4120 assert_eq!(route.paths.len(), 1);
4121 let path = route.paths.last().unwrap();
4122 assert_eq!(path.hops.len(), 2);
4123 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4124 assert_eq!(path.final_value_msat(), 10_000);
4129 fn available_liquidity_last_hop_test() {
4130 // Check that available liquidity properly limits the path even when only
4131 // one of the latter hops is limited.
4132 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4133 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4134 let scorer = ln_test_utils::TestScorer::new();
4135 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4136 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4137 let config = UserConfig::default();
4138 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4140 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4141 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
4142 // Total capacity: 50 sats.
4144 // Disable other potential paths.
4145 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4146 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4147 short_channel_id: 2,
4150 cltv_expiry_delta: 0,
4151 htlc_minimum_msat: 0,
4152 htlc_maximum_msat: 100_000,
4154 fee_proportional_millionths: 0,
4155 excess_data: Vec::new()
4157 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4158 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4159 short_channel_id: 7,
4162 cltv_expiry_delta: 0,
4163 htlc_minimum_msat: 0,
4164 htlc_maximum_msat: 100_000,
4166 fee_proportional_millionths: 0,
4167 excess_data: Vec::new()
4172 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4173 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4174 short_channel_id: 12,
4177 cltv_expiry_delta: 0,
4178 htlc_minimum_msat: 0,
4179 htlc_maximum_msat: 100_000,
4181 fee_proportional_millionths: 0,
4182 excess_data: Vec::new()
4184 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4185 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4186 short_channel_id: 13,
4189 cltv_expiry_delta: 0,
4190 htlc_minimum_msat: 0,
4191 htlc_maximum_msat: 100_000,
4193 fee_proportional_millionths: 0,
4194 excess_data: Vec::new()
4197 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4198 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4199 short_channel_id: 6,
4202 cltv_expiry_delta: 0,
4203 htlc_minimum_msat: 0,
4204 htlc_maximum_msat: 50_000,
4206 fee_proportional_millionths: 0,
4207 excess_data: Vec::new()
4209 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4210 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4211 short_channel_id: 11,
4214 cltv_expiry_delta: 0,
4215 htlc_minimum_msat: 0,
4216 htlc_maximum_msat: 100_000,
4218 fee_proportional_millionths: 0,
4219 excess_data: Vec::new()
4222 // Attempt to route more than available results in a failure.
4223 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4224 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4225 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4226 } else { panic!(); }
4230 // Now, attempt to route 49 sats (just a bit below the capacity).
4231 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4232 assert_eq!(route.paths.len(), 1);
4233 let mut total_amount_paid_msat = 0;
4234 for path in &route.paths {
4235 assert_eq!(path.hops.len(), 4);
4236 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4237 total_amount_paid_msat += path.final_value_msat();
4239 assert_eq!(total_amount_paid_msat, 49_000);
4243 // Attempt to route an exact amount is also fine
4244 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4245 assert_eq!(route.paths.len(), 1);
4246 let mut total_amount_paid_msat = 0;
4247 for path in &route.paths {
4248 assert_eq!(path.hops.len(), 4);
4249 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4250 total_amount_paid_msat += path.final_value_msat();
4252 assert_eq!(total_amount_paid_msat, 50_000);
4257 fn ignore_fee_first_hop_test() {
4258 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4259 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4260 let scorer = ln_test_utils::TestScorer::new();
4261 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4262 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4263 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
4265 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4266 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4267 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4268 short_channel_id: 1,
4271 cltv_expiry_delta: 0,
4272 htlc_minimum_msat: 0,
4273 htlc_maximum_msat: 100_000,
4274 fee_base_msat: 1_000_000,
4275 fee_proportional_millionths: 0,
4276 excess_data: Vec::new()
4278 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4279 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4280 short_channel_id: 3,
4283 cltv_expiry_delta: 0,
4284 htlc_minimum_msat: 0,
4285 htlc_maximum_msat: 50_000,
4287 fee_proportional_millionths: 0,
4288 excess_data: Vec::new()
4292 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4293 assert_eq!(route.paths.len(), 1);
4294 let mut total_amount_paid_msat = 0;
4295 for path in &route.paths {
4296 assert_eq!(path.hops.len(), 2);
4297 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4298 total_amount_paid_msat += path.final_value_msat();
4300 assert_eq!(total_amount_paid_msat, 50_000);
4305 fn simple_mpp_route_test() {
4306 let (secp_ctx, _, _, _, _) = build_graph();
4307 let (_, _, _, nodes) = get_nodes(&secp_ctx);
4308 let config = UserConfig::default();
4309 let clear_payment_params = PaymentParameters::from_node_id(nodes[2], 42)
4310 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4311 do_simple_mpp_route_test(clear_payment_params);
4313 // MPP to a 1-hop blinded path for nodes[2]
4314 let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
4315 let blinded_path = BlindedPath {
4316 introduction_node_id: nodes[2],
4317 blinding_point: ln_test_utils::pubkey(42),
4318 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }],
4320 let blinded_payinfo = BlindedPayInfo { // These fields are ignored for 1-hop blinded paths
4322 fee_proportional_millionths: 0,
4323 htlc_minimum_msat: 0,
4324 htlc_maximum_msat: 0,
4325 cltv_expiry_delta: 0,
4326 features: BlindedHopFeatures::empty(),
4328 let one_hop_blinded_payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())])
4329 .with_bolt12_features(bolt12_features.clone()).unwrap();
4330 do_simple_mpp_route_test(one_hop_blinded_payment_params.clone());
4332 // MPP to 3 2-hop blinded paths
4333 let mut blinded_path_node_0 = blinded_path.clone();
4334 blinded_path_node_0.introduction_node_id = nodes[0];
4335 blinded_path_node_0.blinded_hops.push(blinded_path.blinded_hops[0].clone());
4336 let mut node_0_payinfo = blinded_payinfo.clone();
4337 node_0_payinfo.htlc_maximum_msat = 50_000;
4339 let mut blinded_path_node_7 = blinded_path_node_0.clone();
4340 blinded_path_node_7.introduction_node_id = nodes[7];
4341 let mut node_7_payinfo = blinded_payinfo.clone();
4342 node_7_payinfo.htlc_maximum_msat = 60_000;
4344 let mut blinded_path_node_1 = blinded_path_node_0.clone();
4345 blinded_path_node_1.introduction_node_id = nodes[1];
4346 let mut node_1_payinfo = blinded_payinfo.clone();
4347 node_1_payinfo.htlc_maximum_msat = 180_000;
4349 let two_hop_blinded_payment_params = PaymentParameters::blinded(
4351 (node_0_payinfo, blinded_path_node_0),
4352 (node_7_payinfo, blinded_path_node_7),
4353 (node_1_payinfo, blinded_path_node_1)
4355 .with_bolt12_features(bolt12_features).unwrap();
4356 do_simple_mpp_route_test(two_hop_blinded_payment_params);
4360 fn do_simple_mpp_route_test(payment_params: PaymentParameters) {
4361 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4362 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4363 let scorer = ln_test_utils::TestScorer::new();
4364 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4365 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4367 // We need a route consisting of 3 paths:
4368 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4369 // To achieve this, the amount being transferred should be around
4370 // the total capacity of these 3 paths.
4372 // First, we set limits on these (previously unlimited) channels.
4373 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4375 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4376 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4377 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4378 short_channel_id: 1,
4381 cltv_expiry_delta: 0,
4382 htlc_minimum_msat: 0,
4383 htlc_maximum_msat: 100_000,
4385 fee_proportional_millionths: 0,
4386 excess_data: Vec::new()
4388 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4390 short_channel_id: 3,
4393 cltv_expiry_delta: 0,
4394 htlc_minimum_msat: 0,
4395 htlc_maximum_msat: 50_000,
4397 fee_proportional_millionths: 0,
4398 excess_data: Vec::new()
4401 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4402 // (total limit 60).
4403 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4404 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4405 short_channel_id: 12,
4408 cltv_expiry_delta: 0,
4409 htlc_minimum_msat: 0,
4410 htlc_maximum_msat: 60_000,
4412 fee_proportional_millionths: 0,
4413 excess_data: Vec::new()
4415 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4416 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4417 short_channel_id: 13,
4420 cltv_expiry_delta: 0,
4421 htlc_minimum_msat: 0,
4422 htlc_maximum_msat: 60_000,
4424 fee_proportional_millionths: 0,
4425 excess_data: Vec::new()
4428 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4429 // (total capacity 180 sats).
4430 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4431 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4432 short_channel_id: 2,
4435 cltv_expiry_delta: 0,
4436 htlc_minimum_msat: 0,
4437 htlc_maximum_msat: 200_000,
4439 fee_proportional_millionths: 0,
4440 excess_data: Vec::new()
4442 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4443 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4444 short_channel_id: 4,
4447 cltv_expiry_delta: 0,
4448 htlc_minimum_msat: 0,
4449 htlc_maximum_msat: 180_000,
4451 fee_proportional_millionths: 0,
4452 excess_data: Vec::new()
4456 // Attempt to route more than available results in a failure.
4457 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4458 &our_id, &payment_params, &network_graph.read_only(), None, 300_000,
4459 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4460 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4461 } else { panic!(); }
4465 // Attempt to route while setting max_path_count to 0 results in a failure.
4466 let zero_payment_params = payment_params.clone().with_max_path_count(0);
4467 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4468 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100,
4469 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4470 assert_eq!(err, "Can't find a route with no paths allowed.");
4471 } else { panic!(); }
4475 // Attempt to route while setting max_path_count to 3 results in a failure.
4476 // This is the case because the minimal_value_contribution_msat would require each path
4477 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4478 let fail_payment_params = payment_params.clone().with_max_path_count(3);
4479 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4480 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000,
4481 Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4482 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4483 } else { panic!(); }
4487 // Now, attempt to route 250 sats (just a bit below the capacity).
4488 // Our algorithm should provide us with these 3 paths.
4489 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4490 250_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4491 assert_eq!(route.paths.len(), 3);
4492 let mut total_amount_paid_msat = 0;
4493 for path in &route.paths {
4494 if let Some(bt) = &path.blinded_tail {
4495 assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
4497 assert_eq!(path.hops.len(), 2);
4498 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4500 total_amount_paid_msat += path.final_value_msat();
4502 assert_eq!(total_amount_paid_msat, 250_000);
4506 // Attempt to route an exact amount is also fine
4507 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4508 290_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4509 assert_eq!(route.paths.len(), 3);
4510 let mut total_amount_paid_msat = 0;
4511 for path in &route.paths {
4512 if payment_params.payee.blinded_route_hints().len() != 0 {
4513 assert!(path.blinded_tail.is_some()) } else { assert!(path.blinded_tail.is_none()) }
4514 if let Some(bt) = &path.blinded_tail {
4515 assert_eq!(path.hops.len() + if bt.hops.len() == 1 { 0 } else { 1 }, 2);
4516 if bt.hops.len() > 1 {
4517 assert_eq!(path.hops.last().unwrap().pubkey,
4518 payment_params.payee.blinded_route_hints().iter()
4519 .find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
4520 .map(|(_, p)| p.introduction_node_id).unwrap());
4522 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4525 assert_eq!(path.hops.len(), 2);
4526 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4528 total_amount_paid_msat += path.final_value_msat();
4530 assert_eq!(total_amount_paid_msat, 290_000);
4535 fn long_mpp_route_test() {
4536 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4537 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4538 let scorer = ln_test_utils::TestScorer::new();
4539 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4540 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4541 let config = UserConfig::default();
4542 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4544 // We need a route consisting of 3 paths:
4545 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4546 // Note that these paths overlap (channels 5, 12, 13).
4547 // We will route 300 sats.
4548 // Each path will have 100 sats capacity, those channels which
4549 // are used twice will have 200 sats capacity.
4551 // Disable other potential paths.
4552 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4553 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4554 short_channel_id: 2,
4557 cltv_expiry_delta: 0,
4558 htlc_minimum_msat: 0,
4559 htlc_maximum_msat: 100_000,
4561 fee_proportional_millionths: 0,
4562 excess_data: Vec::new()
4564 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4565 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4566 short_channel_id: 7,
4569 cltv_expiry_delta: 0,
4570 htlc_minimum_msat: 0,
4571 htlc_maximum_msat: 100_000,
4573 fee_proportional_millionths: 0,
4574 excess_data: Vec::new()
4577 // Path via {node0, node2} is channels {1, 3, 5}.
4578 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4579 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4580 short_channel_id: 1,
4583 cltv_expiry_delta: 0,
4584 htlc_minimum_msat: 0,
4585 htlc_maximum_msat: 100_000,
4587 fee_proportional_millionths: 0,
4588 excess_data: Vec::new()
4590 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4591 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4592 short_channel_id: 3,
4595 cltv_expiry_delta: 0,
4596 htlc_minimum_msat: 0,
4597 htlc_maximum_msat: 100_000,
4599 fee_proportional_millionths: 0,
4600 excess_data: Vec::new()
4603 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4604 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4605 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4606 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4607 short_channel_id: 5,
4610 cltv_expiry_delta: 0,
4611 htlc_minimum_msat: 0,
4612 htlc_maximum_msat: 200_000,
4614 fee_proportional_millionths: 0,
4615 excess_data: Vec::new()
4618 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4619 // Add 100 sats to the capacities of {12, 13}, because these channels
4620 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4621 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4622 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4623 short_channel_id: 12,
4626 cltv_expiry_delta: 0,
4627 htlc_minimum_msat: 0,
4628 htlc_maximum_msat: 200_000,
4630 fee_proportional_millionths: 0,
4631 excess_data: Vec::new()
4633 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4634 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4635 short_channel_id: 13,
4638 cltv_expiry_delta: 0,
4639 htlc_minimum_msat: 0,
4640 htlc_maximum_msat: 200_000,
4642 fee_proportional_millionths: 0,
4643 excess_data: Vec::new()
4646 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4647 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4648 short_channel_id: 6,
4651 cltv_expiry_delta: 0,
4652 htlc_minimum_msat: 0,
4653 htlc_maximum_msat: 100_000,
4655 fee_proportional_millionths: 0,
4656 excess_data: Vec::new()
4658 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4660 short_channel_id: 11,
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} is channels {12, 13, 5}.
4672 // We already limited them to 200 sats (they are used twice for 100 sats).
4673 // Nothing to do here.
4676 // Attempt to route more than available results in a failure.
4677 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4678 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
4679 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4680 } else { panic!(); }
4684 // Now, attempt to route 300 sats (exact amount we can route).
4685 // Our algorithm should provide us with these 3 paths, 100 sats each.
4686 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4687 assert_eq!(route.paths.len(), 3);
4689 let mut total_amount_paid_msat = 0;
4690 for path in &route.paths {
4691 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4692 total_amount_paid_msat += path.final_value_msat();
4694 assert_eq!(total_amount_paid_msat, 300_000);
4700 fn mpp_cheaper_route_test() {
4701 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4702 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4703 let scorer = ln_test_utils::TestScorer::new();
4704 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4705 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4706 let config = UserConfig::default();
4707 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4709 // This test checks that if we have two cheaper paths and one more expensive path,
4710 // so that liquidity-wise any 2 of 3 combination is sufficient,
4711 // two cheaper paths will be taken.
4712 // These paths have equal available liquidity.
4714 // We need a combination of 3 paths:
4715 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4716 // Note that these paths overlap (channels 5, 12, 13).
4717 // Each path will have 100 sats capacity, those channels which
4718 // are used twice will have 200 sats capacity.
4720 // Disable other potential paths.
4721 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4722 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4723 short_channel_id: 2,
4726 cltv_expiry_delta: 0,
4727 htlc_minimum_msat: 0,
4728 htlc_maximum_msat: 100_000,
4730 fee_proportional_millionths: 0,
4731 excess_data: Vec::new()
4733 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4734 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4735 short_channel_id: 7,
4738 cltv_expiry_delta: 0,
4739 htlc_minimum_msat: 0,
4740 htlc_maximum_msat: 100_000,
4742 fee_proportional_millionths: 0,
4743 excess_data: Vec::new()
4746 // Path via {node0, node2} is channels {1, 3, 5}.
4747 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4748 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4749 short_channel_id: 1,
4752 cltv_expiry_delta: 0,
4753 htlc_minimum_msat: 0,
4754 htlc_maximum_msat: 100_000,
4756 fee_proportional_millionths: 0,
4757 excess_data: Vec::new()
4759 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4760 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4761 short_channel_id: 3,
4764 cltv_expiry_delta: 0,
4765 htlc_minimum_msat: 0,
4766 htlc_maximum_msat: 100_000,
4768 fee_proportional_millionths: 0,
4769 excess_data: Vec::new()
4772 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4773 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4774 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4775 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4776 short_channel_id: 5,
4779 cltv_expiry_delta: 0,
4780 htlc_minimum_msat: 0,
4781 htlc_maximum_msat: 200_000,
4783 fee_proportional_millionths: 0,
4784 excess_data: Vec::new()
4787 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4788 // Add 100 sats to the capacities of {12, 13}, because these channels
4789 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4790 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4791 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4792 short_channel_id: 12,
4795 cltv_expiry_delta: 0,
4796 htlc_minimum_msat: 0,
4797 htlc_maximum_msat: 200_000,
4799 fee_proportional_millionths: 0,
4800 excess_data: Vec::new()
4802 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4803 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4804 short_channel_id: 13,
4807 cltv_expiry_delta: 0,
4808 htlc_minimum_msat: 0,
4809 htlc_maximum_msat: 200_000,
4811 fee_proportional_millionths: 0,
4812 excess_data: Vec::new()
4815 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4816 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4817 short_channel_id: 6,
4820 cltv_expiry_delta: 0,
4821 htlc_minimum_msat: 0,
4822 htlc_maximum_msat: 100_000,
4823 fee_base_msat: 1_000,
4824 fee_proportional_millionths: 0,
4825 excess_data: Vec::new()
4827 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4828 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4829 short_channel_id: 11,
4832 cltv_expiry_delta: 0,
4833 htlc_minimum_msat: 0,
4834 htlc_maximum_msat: 100_000,
4836 fee_proportional_millionths: 0,
4837 excess_data: Vec::new()
4840 // Path via {node7, node2} is channels {12, 13, 5}.
4841 // We already limited them to 200 sats (they are used twice for 100 sats).
4842 // Nothing to do here.
4845 // Now, attempt to route 180 sats.
4846 // Our algorithm should provide us with these 2 paths.
4847 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
4848 assert_eq!(route.paths.len(), 2);
4850 let mut total_value_transferred_msat = 0;
4851 let mut total_paid_msat = 0;
4852 for path in &route.paths {
4853 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4854 total_value_transferred_msat += path.final_value_msat();
4855 for hop in &path.hops {
4856 total_paid_msat += hop.fee_msat;
4859 // If we paid fee, this would be higher.
4860 assert_eq!(total_value_transferred_msat, 180_000);
4861 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4862 assert_eq!(total_fees_paid, 0);
4867 fn fees_on_mpp_route_test() {
4868 // This test makes sure that MPP algorithm properly takes into account
4869 // fees charged on the channels, by making the fees impactful:
4870 // if the fee is not properly accounted for, the behavior is different.
4871 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4872 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4873 let scorer = ln_test_utils::TestScorer::new();
4874 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4875 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4876 let config = UserConfig::default();
4877 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
4879 // We need a route consisting of 2 paths:
4880 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4881 // We will route 200 sats, Each path will have 100 sats capacity.
4883 // This test is not particularly stable: e.g.,
4884 // there's a way to route via {node0, node2, node4}.
4885 // It works while pathfinding is deterministic, but can be broken otherwise.
4886 // It's fine to ignore this concern for now.
4888 // Disable other potential paths.
4889 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4890 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4891 short_channel_id: 2,
4894 cltv_expiry_delta: 0,
4895 htlc_minimum_msat: 0,
4896 htlc_maximum_msat: 100_000,
4898 fee_proportional_millionths: 0,
4899 excess_data: Vec::new()
4902 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4903 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4904 short_channel_id: 7,
4907 cltv_expiry_delta: 0,
4908 htlc_minimum_msat: 0,
4909 htlc_maximum_msat: 100_000,
4911 fee_proportional_millionths: 0,
4912 excess_data: Vec::new()
4915 // Path via {node0, node2} is channels {1, 3, 5}.
4916 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4917 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4918 short_channel_id: 1,
4921 cltv_expiry_delta: 0,
4922 htlc_minimum_msat: 0,
4923 htlc_maximum_msat: 100_000,
4925 fee_proportional_millionths: 0,
4926 excess_data: Vec::new()
4928 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4929 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4930 short_channel_id: 3,
4933 cltv_expiry_delta: 0,
4934 htlc_minimum_msat: 0,
4935 htlc_maximum_msat: 100_000,
4937 fee_proportional_millionths: 0,
4938 excess_data: Vec::new()
4941 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4942 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4943 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4944 short_channel_id: 5,
4947 cltv_expiry_delta: 0,
4948 htlc_minimum_msat: 0,
4949 htlc_maximum_msat: 100_000,
4951 fee_proportional_millionths: 0,
4952 excess_data: Vec::new()
4955 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4956 // All channels should be 100 sats capacity. But for the fee experiment,
4957 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4958 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4959 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4960 // so no matter how large are other channels,
4961 // the whole path will be limited by 100 sats with just these 2 conditions:
4962 // - channel 12 capacity is 250 sats
4963 // - fee for channel 6 is 150 sats
4964 // Let's test this by enforcing these 2 conditions and removing other limits.
4965 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4966 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4967 short_channel_id: 12,
4970 cltv_expiry_delta: 0,
4971 htlc_minimum_msat: 0,
4972 htlc_maximum_msat: 250_000,
4974 fee_proportional_millionths: 0,
4975 excess_data: Vec::new()
4977 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4978 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4979 short_channel_id: 13,
4982 cltv_expiry_delta: 0,
4983 htlc_minimum_msat: 0,
4984 htlc_maximum_msat: MAX_VALUE_MSAT,
4986 fee_proportional_millionths: 0,
4987 excess_data: Vec::new()
4990 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4991 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4992 short_channel_id: 6,
4995 cltv_expiry_delta: 0,
4996 htlc_minimum_msat: 0,
4997 htlc_maximum_msat: MAX_VALUE_MSAT,
4998 fee_base_msat: 150_000,
4999 fee_proportional_millionths: 0,
5000 excess_data: Vec::new()
5002 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5003 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5004 short_channel_id: 11,
5007 cltv_expiry_delta: 0,
5008 htlc_minimum_msat: 0,
5009 htlc_maximum_msat: MAX_VALUE_MSAT,
5011 fee_proportional_millionths: 0,
5012 excess_data: Vec::new()
5016 // Attempt to route more than available results in a failure.
5017 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5018 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
5019 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5020 } else { panic!(); }
5024 // Now, attempt to route 200 sats (exact amount we can route).
5025 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5026 assert_eq!(route.paths.len(), 2);
5028 let mut total_amount_paid_msat = 0;
5029 for path in &route.paths {
5030 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
5031 total_amount_paid_msat += path.final_value_msat();
5033 assert_eq!(total_amount_paid_msat, 200_000);
5034 assert_eq!(route.get_total_fees(), 150_000);
5039 fn mpp_with_last_hops() {
5040 // Previously, if we tried to send an MPP payment to a destination which was only reachable
5041 // via a single last-hop route hint, we'd fail to route if we first collected routes
5042 // totaling close but not quite enough to fund the full payment.
5044 // This was because we considered last-hop hints to have exactly the sought payment amount
5045 // instead of the amount we were trying to collect, needlessly limiting our path searching
5046 // at the very first hop.
5048 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
5049 // criterion to cause us to refuse all routes at the last hop hint which would be considered
5050 // to only have the remaining to-collect amount in available liquidity.
5052 // This bug appeared in production in some specific channel configurations.
5053 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5054 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5055 let scorer = ln_test_utils::TestScorer::new();
5056 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5057 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5058 let config = UserConfig::default();
5059 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
5060 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
5061 src_node_id: nodes[2],
5062 short_channel_id: 42,
5063 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
5064 cltv_expiry_delta: 42,
5065 htlc_minimum_msat: None,
5066 htlc_maximum_msat: None,
5067 }])]).unwrap().with_max_channel_saturation_power_of_half(0);
5069 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
5070 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
5071 // would first use the no-fee route and then fail to find a path along the second route as
5072 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
5073 // under 5% of our payment amount.
5074 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5075 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5076 short_channel_id: 1,
5079 cltv_expiry_delta: (5 << 4) | 5,
5080 htlc_minimum_msat: 0,
5081 htlc_maximum_msat: 99_000,
5082 fee_base_msat: u32::max_value(),
5083 fee_proportional_millionths: u32::max_value(),
5084 excess_data: Vec::new()
5086 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5087 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5088 short_channel_id: 2,
5091 cltv_expiry_delta: (5 << 4) | 3,
5092 htlc_minimum_msat: 0,
5093 htlc_maximum_msat: 99_000,
5094 fee_base_msat: u32::max_value(),
5095 fee_proportional_millionths: u32::max_value(),
5096 excess_data: Vec::new()
5098 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5099 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5100 short_channel_id: 4,
5103 cltv_expiry_delta: (4 << 4) | 1,
5104 htlc_minimum_msat: 0,
5105 htlc_maximum_msat: MAX_VALUE_MSAT,
5107 fee_proportional_millionths: 0,
5108 excess_data: Vec::new()
5110 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5111 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5112 short_channel_id: 13,
5114 flags: 0|2, // Channel disabled
5115 cltv_expiry_delta: (13 << 4) | 1,
5116 htlc_minimum_msat: 0,
5117 htlc_maximum_msat: MAX_VALUE_MSAT,
5119 fee_proportional_millionths: 2000000,
5120 excess_data: Vec::new()
5123 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
5125 let mut route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5126 assert_eq!(route.paths.len(), 2);
5127 route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
5128 // Paths are manually ordered ordered by SCID, so:
5129 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
5130 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
5131 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
5132 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
5133 assert_eq!(route.paths[0].hops[2].fee_msat, 99_000);
5134 assert_eq!(route.paths[1].hops[0].short_channel_id, 2);
5135 assert_eq!(route.paths[1].hops[0].fee_msat, 1);
5136 assert_eq!(route.paths[1].hops[2].fee_msat, 1_000);
5137 assert_eq!(route.get_total_fees(), 1);
5138 assert_eq!(route.get_total_amount(), 100_000);
5142 fn drop_lowest_channel_mpp_route_test() {
5143 // This test checks that low-capacity channel is dropped when after
5144 // path finding we realize that we found more capacity than we need.
5145 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5146 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5147 let scorer = ln_test_utils::TestScorer::new();
5148 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5149 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5150 let config = UserConfig::default();
5151 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap()
5152 .with_max_channel_saturation_power_of_half(0);
5154 // We need a route consisting of 3 paths:
5155 // From our node to node2 via node0, node7, node1 (three paths one hop each).
5157 // The first and the second paths should be sufficient, but the third should be
5158 // cheaper, so that we select it but drop later.
5160 // First, we set limits on these (previously unlimited) channels.
5161 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
5163 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
5164 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5165 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5166 short_channel_id: 1,
5169 cltv_expiry_delta: 0,
5170 htlc_minimum_msat: 0,
5171 htlc_maximum_msat: 100_000,
5173 fee_proportional_millionths: 0,
5174 excess_data: Vec::new()
5176 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
5177 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5178 short_channel_id: 3,
5181 cltv_expiry_delta: 0,
5182 htlc_minimum_msat: 0,
5183 htlc_maximum_msat: 50_000,
5185 fee_proportional_millionths: 0,
5186 excess_data: Vec::new()
5189 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
5190 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5191 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5192 short_channel_id: 12,
5195 cltv_expiry_delta: 0,
5196 htlc_minimum_msat: 0,
5197 htlc_maximum_msat: 60_000,
5199 fee_proportional_millionths: 0,
5200 excess_data: Vec::new()
5202 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5203 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5204 short_channel_id: 13,
5207 cltv_expiry_delta: 0,
5208 htlc_minimum_msat: 0,
5209 htlc_maximum_msat: 60_000,
5211 fee_proportional_millionths: 0,
5212 excess_data: Vec::new()
5215 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
5216 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5217 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5218 short_channel_id: 2,
5221 cltv_expiry_delta: 0,
5222 htlc_minimum_msat: 0,
5223 htlc_maximum_msat: 20_000,
5225 fee_proportional_millionths: 0,
5226 excess_data: Vec::new()
5228 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5229 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5230 short_channel_id: 4,
5233 cltv_expiry_delta: 0,
5234 htlc_minimum_msat: 0,
5235 htlc_maximum_msat: 20_000,
5237 fee_proportional_millionths: 0,
5238 excess_data: Vec::new()
5242 // Attempt to route more than available results in a failure.
5243 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
5244 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
5245 assert_eq!(err, "Failed to find a sufficient route to the given destination");
5246 } else { panic!(); }
5250 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
5251 // Our algorithm should provide us with these 3 paths.
5252 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5253 assert_eq!(route.paths.len(), 3);
5254 let mut total_amount_paid_msat = 0;
5255 for path in &route.paths {
5256 assert_eq!(path.hops.len(), 2);
5257 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5258 total_amount_paid_msat += path.final_value_msat();
5260 assert_eq!(total_amount_paid_msat, 125_000);
5264 // Attempt to route without the last small cheap channel
5265 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5266 assert_eq!(route.paths.len(), 2);
5267 let mut total_amount_paid_msat = 0;
5268 for path in &route.paths {
5269 assert_eq!(path.hops.len(), 2);
5270 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
5271 total_amount_paid_msat += path.final_value_msat();
5273 assert_eq!(total_amount_paid_msat, 90_000);
5278 fn min_criteria_consistency() {
5279 // Test that we don't use an inconsistent metric between updating and walking nodes during
5280 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
5281 // was updated with a different criterion from the heap sorting, resulting in loops in
5282 // calculated paths. We test for that specific case here.
5284 // We construct a network that looks like this:
5286 // node2 -1(3)2- node3
5290 // node1 -1(5)2- node4 -1(1)2- node6
5296 // We create a loop on the side of our real path - our destination is node 6, with a
5297 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
5298 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
5299 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
5300 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
5301 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
5302 // "previous hop" being set to node 3, creating a loop in the path.
5303 let secp_ctx = Secp256k1::new();
5304 let logger = Arc::new(ln_test_utils::TestLogger::new());
5305 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
5306 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
5307 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5308 let scorer = ln_test_utils::TestScorer::new();
5309 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5310 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5311 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
5313 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
5314 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5315 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5316 short_channel_id: 6,
5319 cltv_expiry_delta: (6 << 4) | 0,
5320 htlc_minimum_msat: 0,
5321 htlc_maximum_msat: MAX_VALUE_MSAT,
5323 fee_proportional_millionths: 0,
5324 excess_data: Vec::new()
5326 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
5328 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
5329 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5330 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5331 short_channel_id: 5,
5334 cltv_expiry_delta: (5 << 4) | 0,
5335 htlc_minimum_msat: 0,
5336 htlc_maximum_msat: MAX_VALUE_MSAT,
5338 fee_proportional_millionths: 0,
5339 excess_data: Vec::new()
5341 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
5343 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
5344 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5345 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5346 short_channel_id: 4,
5349 cltv_expiry_delta: (4 << 4) | 0,
5350 htlc_minimum_msat: 0,
5351 htlc_maximum_msat: MAX_VALUE_MSAT,
5353 fee_proportional_millionths: 0,
5354 excess_data: Vec::new()
5356 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
5358 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
5359 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
5360 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5361 short_channel_id: 3,
5364 cltv_expiry_delta: (3 << 4) | 0,
5365 htlc_minimum_msat: 0,
5366 htlc_maximum_msat: MAX_VALUE_MSAT,
5368 fee_proportional_millionths: 0,
5369 excess_data: Vec::new()
5371 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
5373 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
5374 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5375 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5376 short_channel_id: 2,
5379 cltv_expiry_delta: (2 << 4) | 0,
5380 htlc_minimum_msat: 0,
5381 htlc_maximum_msat: MAX_VALUE_MSAT,
5383 fee_proportional_millionths: 0,
5384 excess_data: Vec::new()
5387 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
5388 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5390 short_channel_id: 1,
5393 cltv_expiry_delta: (1 << 4) | 0,
5394 htlc_minimum_msat: 100,
5395 htlc_maximum_msat: MAX_VALUE_MSAT,
5397 fee_proportional_millionths: 0,
5398 excess_data: Vec::new()
5400 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
5403 // Now ensure the route flows simply over nodes 1 and 4 to 6.
5404 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5405 assert_eq!(route.paths.len(), 1);
5406 assert_eq!(route.paths[0].hops.len(), 3);
5408 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
5409 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5410 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
5411 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (5 << 4) | 0);
5412 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(1));
5413 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(6));
5415 assert_eq!(route.paths[0].hops[1].pubkey, nodes[4]);
5416 assert_eq!(route.paths[0].hops[1].short_channel_id, 5);
5417 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
5418 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (1 << 4) | 0);
5419 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(4));
5420 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(5));
5422 assert_eq!(route.paths[0].hops[2].pubkey, nodes[6]);
5423 assert_eq!(route.paths[0].hops[2].short_channel_id, 1);
5424 assert_eq!(route.paths[0].hops[2].fee_msat, 10_000);
5425 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
5426 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
5427 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(1));
5433 fn exact_fee_liquidity_limit() {
5434 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5435 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5436 // we calculated fees on a higher value, resulting in us ignoring such paths.
5437 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5438 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5439 let scorer = ln_test_utils::TestScorer::new();
5440 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5441 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5442 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
5444 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5446 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5447 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5448 short_channel_id: 2,
5451 cltv_expiry_delta: 0,
5452 htlc_minimum_msat: 0,
5453 htlc_maximum_msat: 85_000,
5455 fee_proportional_millionths: 0,
5456 excess_data: Vec::new()
5459 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5460 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5461 short_channel_id: 12,
5464 cltv_expiry_delta: (4 << 4) | 1,
5465 htlc_minimum_msat: 0,
5466 htlc_maximum_msat: 270_000,
5468 fee_proportional_millionths: 1000000,
5469 excess_data: Vec::new()
5473 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5474 // 200% fee charged channel 13 in the 1-to-2 direction.
5475 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5476 assert_eq!(route.paths.len(), 1);
5477 assert_eq!(route.paths[0].hops.len(), 2);
5479 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5480 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5481 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5482 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5483 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5484 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5486 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5487 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5488 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5489 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5490 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
5491 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5496 fn htlc_max_reduction_below_min() {
5497 // Test that if, while walking the graph, we reduce the value being sent to meet an
5498 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5499 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5500 // resulting in us thinking there is no possible path, even if other paths exist.
5501 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5502 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5503 let scorer = ln_test_utils::TestScorer::new();
5504 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5505 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5506 let config = UserConfig::default();
5507 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5509 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5510 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5511 // then try to send 90_000.
5512 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5513 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5514 short_channel_id: 2,
5517 cltv_expiry_delta: 0,
5518 htlc_minimum_msat: 0,
5519 htlc_maximum_msat: 80_000,
5521 fee_proportional_millionths: 0,
5522 excess_data: Vec::new()
5524 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5525 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5526 short_channel_id: 4,
5529 cltv_expiry_delta: (4 << 4) | 1,
5530 htlc_minimum_msat: 90_000,
5531 htlc_maximum_msat: MAX_VALUE_MSAT,
5533 fee_proportional_millionths: 0,
5534 excess_data: Vec::new()
5538 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5539 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5540 // expensive) channels 12-13 path.
5541 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5542 assert_eq!(route.paths.len(), 1);
5543 assert_eq!(route.paths[0].hops.len(), 2);
5545 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5546 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5547 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5548 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5549 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5550 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5552 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5553 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5554 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5555 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5556 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), channelmanager::provided_invoice_features(&config).le_flags());
5557 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5562 fn multiple_direct_first_hops() {
5563 // Previously we'd only ever considered one first hop path per counterparty.
5564 // However, as we don't restrict users to one channel per peer, we really need to support
5565 // looking at all first hop paths.
5566 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5567 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5568 // route over multiple channels with the same first hop.
5569 let secp_ctx = Secp256k1::new();
5570 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5571 let logger = Arc::new(ln_test_utils::TestLogger::new());
5572 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
5573 let scorer = ln_test_utils::TestScorer::new();
5574 let config = UserConfig::default();
5575 let payment_params = PaymentParameters::from_node_id(nodes[0], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
5576 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5577 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5580 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5581 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
5582 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
5583 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5584 assert_eq!(route.paths.len(), 1);
5585 assert_eq!(route.paths[0].hops.len(), 1);
5587 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5588 assert_eq!(route.paths[0].hops[0].short_channel_id, 3);
5589 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5592 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5593 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5594 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5595 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5596 assert_eq!(route.paths.len(), 2);
5597 assert_eq!(route.paths[0].hops.len(), 1);
5598 assert_eq!(route.paths[1].hops.len(), 1);
5600 assert!((route.paths[0].hops[0].short_channel_id == 3 && route.paths[1].hops[0].short_channel_id == 2) ||
5601 (route.paths[0].hops[0].short_channel_id == 2 && route.paths[1].hops[0].short_channel_id == 3));
5603 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5604 assert_eq!(route.paths[0].hops[0].fee_msat, 50_000);
5606 assert_eq!(route.paths[1].hops[0].pubkey, nodes[0]);
5607 assert_eq!(route.paths[1].hops[0].fee_msat, 50_000);
5611 // If we have a bunch of outbound channels to the same node, where most are not
5612 // sufficient to pay the full payment, but one is, we should default to just using the
5613 // one single channel that has sufficient balance, avoiding MPP.
5615 // If we have several options above the 3xpayment value threshold, we should pick the
5616 // smallest of them, avoiding further fragmenting our available outbound balance to
5618 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5619 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5620 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5621 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5622 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
5623 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5624 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5625 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5626 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
5627 ]), 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5628 assert_eq!(route.paths.len(), 1);
5629 assert_eq!(route.paths[0].hops.len(), 1);
5631 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5632 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5633 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5638 fn prefers_shorter_route_with_higher_fees() {
5639 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5640 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5641 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5643 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5644 let scorer = ln_test_utils::TestScorer::new();
5645 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5646 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5647 let route = get_route(
5648 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5649 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5651 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5653 assert_eq!(route.get_total_fees(), 100);
5654 assert_eq!(route.get_total_amount(), 100);
5655 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5657 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5658 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5659 let scorer = FixedPenaltyScorer::with_penalty(100);
5660 let route = get_route(
5661 &our_id, &payment_params, &network_graph.read_only(), None, 100,
5662 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5664 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5666 assert_eq!(route.get_total_fees(), 300);
5667 assert_eq!(route.get_total_amount(), 100);
5668 assert_eq!(path, vec![2, 4, 7, 10]);
5671 struct BadChannelScorer {
5672 short_channel_id: u64,
5676 impl Writeable for BadChannelScorer {
5677 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5679 impl Score for BadChannelScorer {
5680 type ScoreParams = ();
5681 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5682 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5685 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5686 fn payment_path_successful(&mut self, _path: &Path) {}
5687 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5688 fn probe_successful(&mut self, _path: &Path) {}
5691 struct BadNodeScorer {
5696 impl Writeable for BadNodeScorer {
5697 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5700 impl Score for BadNodeScorer {
5701 type ScoreParams = ();
5702 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage, _score_params:&Self::ScoreParams) -> u64 {
5703 if *target == self.node_id { u64::max_value() } else { 0 }
5706 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5707 fn payment_path_successful(&mut self, _path: &Path) {}
5708 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5709 fn probe_successful(&mut self, _path: &Path) {}
5713 fn avoids_routing_through_bad_channels_and_nodes() {
5714 let (secp_ctx, network, _, _, logger) = build_graph();
5715 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5716 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5717 let network_graph = network.read_only();
5719 // A path to nodes[6] exists when no penalties are applied to any channel.
5720 let scorer = ln_test_utils::TestScorer::new();
5721 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5722 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5723 let route = get_route(
5724 &our_id, &payment_params, &network_graph, None, 100,
5725 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5727 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5729 assert_eq!(route.get_total_fees(), 100);
5730 assert_eq!(route.get_total_amount(), 100);
5731 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5733 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5734 let scorer = BadChannelScorer { short_channel_id: 6 };
5735 let route = get_route(
5736 &our_id, &payment_params, &network_graph, None, 100,
5737 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5739 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5741 assert_eq!(route.get_total_fees(), 300);
5742 assert_eq!(route.get_total_amount(), 100);
5743 assert_eq!(path, vec![2, 4, 7, 10]);
5745 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5746 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5748 &our_id, &payment_params, &network_graph, None, 100,
5749 Arc::clone(&logger), &scorer, &(), &random_seed_bytes
5751 Err(LightningError { err, .. } ) => {
5752 assert_eq!(err, "Failed to find a path to the given destination");
5754 Ok(_) => panic!("Expected error"),
5759 fn total_fees_single_path() {
5761 paths: vec![Path { hops: vec![
5763 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5764 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5765 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5768 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5769 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5770 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5773 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5774 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5775 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5777 ], blinded_tail: None }],
5778 payment_params: None,
5781 assert_eq!(route.get_total_fees(), 250);
5782 assert_eq!(route.get_total_amount(), 225);
5786 fn total_fees_multi_path() {
5788 paths: vec![Path { hops: vec![
5790 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5791 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5792 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5795 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5796 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5797 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5799 ], blinded_tail: None }, Path { hops: vec![
5801 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5802 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5803 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5806 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5807 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5808 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5810 ], blinded_tail: None }],
5811 payment_params: None,
5814 assert_eq!(route.get_total_fees(), 200);
5815 assert_eq!(route.get_total_amount(), 300);
5819 fn total_empty_route_no_panic() {
5820 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5821 // would both panic if the route was completely empty. We test to ensure they return 0
5822 // here, even though its somewhat nonsensical as a route.
5823 let route = Route { paths: Vec::new(), payment_params: None };
5825 assert_eq!(route.get_total_fees(), 0);
5826 assert_eq!(route.get_total_amount(), 0);
5830 fn limits_total_cltv_delta() {
5831 let (secp_ctx, network, _, _, logger) = build_graph();
5832 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5833 let network_graph = network.read_only();
5835 let scorer = ln_test_utils::TestScorer::new();
5837 // Make sure that generally there is at least one route available
5838 let feasible_max_total_cltv_delta = 1008;
5839 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5840 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5841 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5842 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5843 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5844 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5845 assert_ne!(path.len(), 0);
5847 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5848 let fail_max_total_cltv_delta = 23;
5849 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5850 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5851 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5853 Err(LightningError { err, .. } ) => {
5854 assert_eq!(err, "Failed to find a path to the given destination");
5856 Ok(_) => panic!("Expected error"),
5861 fn avoids_recently_failed_paths() {
5862 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
5863 // randomly inserting channels into it until we can't find a route anymore.
5864 let (secp_ctx, network, _, _, logger) = build_graph();
5865 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5866 let network_graph = network.read_only();
5868 let scorer = ln_test_utils::TestScorer::new();
5869 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes)).unwrap()
5870 .with_max_path_count(1);
5871 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5872 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5874 // We should be able to find a route initially, and then after we fail a few random
5875 // channels eventually we won't be able to any longer.
5876 assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).is_ok());
5878 if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes) {
5879 for chan in route.paths[0].hops.iter() {
5880 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
5882 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
5883 % route.paths[0].hops.len();
5884 payment_params.previously_failed_channels.push(route.paths[0].hops[victim].short_channel_id);
5890 fn limits_path_length() {
5891 let (secp_ctx, network, _, _, logger) = build_line_graph();
5892 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5893 let network_graph = network.read_only();
5895 let scorer = ln_test_utils::TestScorer::new();
5896 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5897 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5899 // First check we can actually create a long route on this graph.
5900 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
5901 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100,
5902 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5903 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5904 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5906 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5907 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
5908 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100,
5909 Arc::clone(&logger), &scorer, &(), &random_seed_bytes)
5911 Err(LightningError { err, .. } ) => {
5912 assert_eq!(err, "Failed to find a path to the given destination");
5914 Ok(_) => panic!("Expected error"),
5919 fn adds_and_limits_cltv_offset() {
5920 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5921 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5923 let scorer = ln_test_utils::TestScorer::new();
5925 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes)).unwrap();
5926 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5927 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5928 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5929 assert_eq!(route.paths.len(), 1);
5931 let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5933 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5934 let mut route_default = route.clone();
5935 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5936 let cltv_expiry_deltas_default = route_default.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5937 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5938 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5939 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5941 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5942 let mut route_limited = route.clone();
5943 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5944 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5945 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5946 let cltv_expiry_deltas_limited = route_limited.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5947 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5951 fn adds_plausible_cltv_offset() {
5952 let (secp_ctx, network, _, _, logger) = build_graph();
5953 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5954 let network_graph = network.read_only();
5955 let network_nodes = network_graph.nodes();
5956 let network_channels = network_graph.channels();
5957 let scorer = ln_test_utils::TestScorer::new();
5958 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5959 let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5960 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5962 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100,
5963 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
5964 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5966 let mut path_plausibility = vec![];
5968 for p in route.paths {
5969 // 1. Select random observation point
5970 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5971 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5973 prng.process_in_place(&mut random_bytes);
5974 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.hops.len());
5975 let observation_point = NodeId::from_pubkey(&p.hops.get(random_path_index).unwrap().pubkey);
5977 // 2. Calculate what CLTV expiry delta we would observe there
5978 let observed_cltv_expiry_delta: u32 = p.hops[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5980 // 3. Starting from the observation point, find candidate paths
5981 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5982 candidates.push_back((observation_point, vec![]));
5984 let mut found_plausible_candidate = false;
5986 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5987 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5988 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5989 found_plausible_candidate = true;
5990 break 'candidate_loop;
5994 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5995 for channel_id in &cur_node.channels {
5996 if let Some(channel_info) = network_channels.get(&channel_id) {
5997 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5998 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
5999 if cur_path_cltv_deltas.iter().sum::<u32>()
6000 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
6001 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
6002 new_path_cltv_deltas.push(next_cltv_expiry_delta);
6003 candidates.push_back((*next_id, new_path_cltv_deltas));
6011 path_plausibility.push(found_plausible_candidate);
6013 assert!(path_plausibility.iter().all(|x| *x));
6017 fn builds_correct_path_from_hops() {
6018 let (secp_ctx, network, _, _, logger) = build_graph();
6019 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6020 let network_graph = network.read_only();
6022 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6023 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6025 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
6026 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
6027 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
6028 &network_graph, 100, Arc::clone(&logger), &random_seed_bytes).unwrap();
6029 let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
6030 assert_eq!(hops.len(), route.paths[0].hops.len());
6031 for (idx, hop_pubkey) in hops.iter().enumerate() {
6032 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
6037 fn avoids_saturating_channels() {
6038 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
6039 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
6040 let decay_params = ProbabilisticScoringDecayParameters::default();
6041 let scorer = ProbabilisticScorer::new(decay_params, &*network_graph, Arc::clone(&logger));
6043 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
6044 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
6045 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
6046 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
6047 short_channel_id: 4,
6050 cltv_expiry_delta: (4 << 4) | 1,
6051 htlc_minimum_msat: 0,
6052 htlc_maximum_msat: 250_000_000,
6054 fee_proportional_millionths: 0,
6055 excess_data: Vec::new()
6057 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
6058 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
6059 short_channel_id: 13,
6062 cltv_expiry_delta: (13 << 4) | 1,
6063 htlc_minimum_msat: 0,
6064 htlc_maximum_msat: 250_000_000,
6066 fee_proportional_millionths: 0,
6067 excess_data: Vec::new()
6070 let config = UserConfig::default();
6071 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6072 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6073 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6074 // 100,000 sats is less than the available liquidity on each channel, set above.
6075 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();
6076 assert_eq!(route.paths.len(), 2);
6077 assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
6078 (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
6081 #[cfg(not(feature = "no-std"))]
6082 pub(super) fn random_init_seed() -> u64 {
6083 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
6084 use core::hash::{BuildHasher, Hasher};
6085 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
6086 println!("Using seed of {}", seed);
6091 #[cfg(not(feature = "no-std"))]
6092 fn generate_routes() {
6093 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
6095 let logger = ln_test_utils::TestLogger::new();
6096 let graph = match super::bench_utils::read_network_graph(&logger) {
6104 let params = ProbabilisticScoringFeeParameters::default();
6105 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
6106 let features = super::Bolt11InvoiceFeatures::empty();
6108 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
6112 #[cfg(not(feature = "no-std"))]
6113 fn generate_routes_mpp() {
6114 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
6116 let logger = ln_test_utils::TestLogger::new();
6117 let graph = match super::bench_utils::read_network_graph(&logger) {
6125 let params = ProbabilisticScoringFeeParameters::default();
6126 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
6127 let features = channelmanager::provided_invoice_features(&UserConfig::default());
6129 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 0, 2);
6133 #[cfg(not(feature = "no-std"))]
6134 fn generate_large_mpp_routes() {
6135 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringFeeParameters};
6137 let logger = ln_test_utils::TestLogger::new();
6138 let graph = match super::bench_utils::read_network_graph(&logger) {
6146 let params = ProbabilisticScoringFeeParameters::default();
6147 let mut scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &graph, &logger);
6148 let features = channelmanager::provided_invoice_features(&UserConfig::default());
6150 super::bench_utils::generate_test_routes(&graph, &mut scorer, ¶ms, features, random_init_seed(), 1_000_000, 2);
6154 fn honors_manual_penalties() {
6155 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
6156 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6158 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6159 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6161 let mut scorer_params = ProbabilisticScoringFeeParameters::default();
6162 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), Arc::clone(&network_graph), Arc::clone(&logger));
6164 // First check set manual penalties are returned by the scorer.
6165 let usage = ChannelUsage {
6167 inflight_htlc_msat: 0,
6168 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
6170 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
6171 scorer_params.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
6172 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage, &scorer_params), 456);
6174 // Then check we can get a normal route
6175 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
6176 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
6177 assert!(route.is_ok());
6179 // Then check that we can't get a route if we ban an intermediate node.
6180 scorer_params.add_banned(&NodeId::from_pubkey(&nodes[3]));
6181 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
6182 assert!(route.is_err());
6184 // Finally make sure we can route again, when we remove the ban.
6185 scorer_params.remove_banned(&NodeId::from_pubkey(&nodes[3]));
6186 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, Arc::clone(&logger), &scorer, &scorer_params,&random_seed_bytes);
6187 assert!(route.is_ok());
6191 fn abide_by_route_hint_max_htlc() {
6192 // Check that we abide by any htlc_maximum_msat provided in the route hints of the payment
6193 // params in the final route.
6194 let (secp_ctx, network_graph, _, _, logger) = build_graph();
6195 let netgraph = network_graph.read_only();
6196 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6197 let scorer = ln_test_utils::TestScorer::new();
6198 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6199 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6200 let config = UserConfig::default();
6202 let max_htlc_msat = 50_000;
6203 let route_hint_1 = RouteHint(vec![RouteHintHop {
6204 src_node_id: nodes[2],
6205 short_channel_id: 42,
6208 proportional_millionths: 0,
6210 cltv_expiry_delta: 10,
6211 htlc_minimum_msat: None,
6212 htlc_maximum_msat: Some(max_htlc_msat),
6214 let dest_node_id = ln_test_utils::pubkey(42);
6215 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
6216 .with_route_hints(vec![route_hint_1.clone()]).unwrap()
6217 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6219 // Make sure we'll error if our route hints don't have enough liquidity according to their
6220 // htlc_maximum_msat.
6221 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id,
6222 &payment_params, &netgraph, None, max_htlc_msat + 1, Arc::clone(&logger), &scorer, &(),
6225 assert_eq!(err, "Failed to find a sufficient route to the given destination");
6226 } else { panic!(); }
6228 // Make sure we'll split an MPP payment across route hints if their htlc_maximum_msat warrants.
6229 let mut route_hint_2 = route_hint_1.clone();
6230 route_hint_2.0[0].short_channel_id = 43;
6231 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
6232 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
6233 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6234 let route = get_route(&our_id, &payment_params, &netgraph, None, max_htlc_msat + 1,
6235 Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
6236 assert_eq!(route.paths.len(), 2);
6237 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6238 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6242 fn direct_channel_to_hints_with_max_htlc() {
6243 // Check that if we have a first hop channel peer that's connected to multiple provided route
6244 // hints, that we properly split the payment between the route hints if needed.
6245 let logger = Arc::new(ln_test_utils::TestLogger::new());
6246 let network_graph = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
6247 let scorer = ln_test_utils::TestScorer::new();
6248 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6249 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6250 let config = UserConfig::default();
6252 let our_node_id = ln_test_utils::pubkey(42);
6253 let intermed_node_id = ln_test_utils::pubkey(43);
6254 let first_hop = vec![get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), 10_000_000)];
6256 let amt_msat = 900_000;
6257 let max_htlc_msat = 500_000;
6258 let route_hint_1 = RouteHint(vec![RouteHintHop {
6259 src_node_id: intermed_node_id,
6260 short_channel_id: 44,
6263 proportional_millionths: 0,
6265 cltv_expiry_delta: 10,
6266 htlc_minimum_msat: None,
6267 htlc_maximum_msat: Some(max_htlc_msat),
6269 src_node_id: intermed_node_id,
6270 short_channel_id: 45,
6273 proportional_millionths: 0,
6275 cltv_expiry_delta: 10,
6276 htlc_minimum_msat: None,
6277 // Check that later route hint max htlcs don't override earlier ones
6278 htlc_maximum_msat: Some(max_htlc_msat - 50),
6280 let mut route_hint_2 = route_hint_1.clone();
6281 route_hint_2.0[0].short_channel_id = 46;
6282 route_hint_2.0[1].short_channel_id = 47;
6283 let dest_node_id = ln_test_utils::pubkey(44);
6284 let payment_params = PaymentParameters::from_node_id(dest_node_id, 42)
6285 .with_route_hints(vec![route_hint_1, route_hint_2]).unwrap()
6286 .with_bolt11_features(channelmanager::provided_invoice_features(&config)).unwrap();
6288 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6289 Some(&first_hop.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6290 &random_seed_bytes).unwrap();
6291 assert_eq!(route.paths.len(), 2);
6292 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6293 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6294 assert_eq!(route.get_total_amount(), amt_msat);
6296 // Re-run but with two first hop channels connected to the same route hint peers that must be
6298 let first_hops = vec![
6299 get_channel_details(Some(42), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6300 get_channel_details(Some(43), intermed_node_id, InitFeatures::from_le_bytes(vec![0b11]), amt_msat - 10),
6302 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6303 Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6304 &random_seed_bytes).unwrap();
6305 assert_eq!(route.paths.len(), 2);
6306 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6307 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6308 assert_eq!(route.get_total_amount(), amt_msat);
6310 // Make sure this works for blinded route hints.
6311 let blinded_path = BlindedPath {
6312 introduction_node_id: intermed_node_id,
6313 blinding_point: ln_test_utils::pubkey(42),
6315 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42), encrypted_payload: vec![] },
6316 BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![] },
6319 let blinded_payinfo = BlindedPayInfo {
6321 fee_proportional_millionths: 0,
6322 htlc_minimum_msat: 1,
6323 htlc_maximum_msat: max_htlc_msat,
6324 cltv_expiry_delta: 10,
6325 features: BlindedHopFeatures::empty(),
6327 let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
6328 let payment_params = PaymentParameters::blinded(vec![
6329 (blinded_payinfo.clone(), blinded_path.clone()),
6330 (blinded_payinfo.clone(), blinded_path.clone())])
6331 .with_bolt12_features(bolt12_features).unwrap();
6332 let route = get_route(&our_node_id, &payment_params, &network_graph.read_only(),
6333 Some(&first_hops.iter().collect::<Vec<_>>()), amt_msat, Arc::clone(&logger), &scorer, &(),
6334 &random_seed_bytes).unwrap();
6335 assert_eq!(route.paths.len(), 2);
6336 assert!(route.paths[0].hops.last().unwrap().fee_msat <= max_htlc_msat);
6337 assert!(route.paths[1].hops.last().unwrap().fee_msat <= max_htlc_msat);
6338 assert_eq!(route.get_total_amount(), amt_msat);
6342 fn blinded_route_ser() {
6343 let blinded_path_1 = BlindedPath {
6344 introduction_node_id: ln_test_utils::pubkey(42),
6345 blinding_point: ln_test_utils::pubkey(43),
6347 BlindedHop { blinded_node_id: ln_test_utils::pubkey(44), encrypted_payload: Vec::new() },
6348 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() }
6351 let blinded_path_2 = BlindedPath {
6352 introduction_node_id: ln_test_utils::pubkey(46),
6353 blinding_point: ln_test_utils::pubkey(47),
6355 BlindedHop { blinded_node_id: ln_test_utils::pubkey(48), encrypted_payload: Vec::new() },
6356 BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }
6359 // (De)serialize a Route with 1 blinded path out of two total paths.
6360 let mut route = Route { paths: vec![Path {
6361 hops: vec![RouteHop {
6362 pubkey: ln_test_utils::pubkey(50),
6363 node_features: NodeFeatures::empty(),
6364 short_channel_id: 42,
6365 channel_features: ChannelFeatures::empty(),
6367 cltv_expiry_delta: 0,
6369 blinded_tail: Some(BlindedTail {
6370 hops: blinded_path_1.blinded_hops,
6371 blinding_point: blinded_path_1.blinding_point,
6372 excess_final_cltv_expiry_delta: 40,
6373 final_value_msat: 100,
6375 hops: vec![RouteHop {
6376 pubkey: ln_test_utils::pubkey(51),
6377 node_features: NodeFeatures::empty(),
6378 short_channel_id: 43,
6379 channel_features: ChannelFeatures::empty(),
6381 cltv_expiry_delta: 0,
6382 }], blinded_tail: None }],
6383 payment_params: None,
6385 let encoded_route = route.encode();
6386 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6387 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6388 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6390 // (De)serialize a Route with two paths, each containing a blinded tail.
6391 route.paths[1].blinded_tail = Some(BlindedTail {
6392 hops: blinded_path_2.blinded_hops,
6393 blinding_point: blinded_path_2.blinding_point,
6394 excess_final_cltv_expiry_delta: 41,
6395 final_value_msat: 101,
6397 let encoded_route = route.encode();
6398 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
6399 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
6400 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
6404 fn blinded_path_inflight_processing() {
6405 // Ensure we'll score the channel that's inbound to a blinded path's introduction node, and
6406 // account for the blinded tail's final amount_msat.
6407 let mut inflight_htlcs = InFlightHtlcs::new();
6408 let blinded_path = BlindedPath {
6409 introduction_node_id: ln_test_utils::pubkey(43),
6410 blinding_point: ln_test_utils::pubkey(48),
6411 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }],
6414 hops: vec![RouteHop {
6415 pubkey: ln_test_utils::pubkey(42),
6416 node_features: NodeFeatures::empty(),
6417 short_channel_id: 42,
6418 channel_features: ChannelFeatures::empty(),
6420 cltv_expiry_delta: 0,
6423 pubkey: blinded_path.introduction_node_id,
6424 node_features: NodeFeatures::empty(),
6425 short_channel_id: 43,
6426 channel_features: ChannelFeatures::empty(),
6428 cltv_expiry_delta: 0,
6430 blinded_tail: Some(BlindedTail {
6431 hops: blinded_path.blinded_hops,
6432 blinding_point: blinded_path.blinding_point,
6433 excess_final_cltv_expiry_delta: 0,
6434 final_value_msat: 200,
6437 inflight_htlcs.process_path(&path, ln_test_utils::pubkey(44));
6438 assert_eq!(*inflight_htlcs.0.get(&(42, true)).unwrap(), 301);
6439 assert_eq!(*inflight_htlcs.0.get(&(43, false)).unwrap(), 201);
6443 fn blinded_path_cltv_shadow_offset() {
6444 // Make sure we add a shadow offset when sending to blinded paths.
6445 let blinded_path = BlindedPath {
6446 introduction_node_id: ln_test_utils::pubkey(43),
6447 blinding_point: ln_test_utils::pubkey(44),
6449 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() },
6450 BlindedHop { blinded_node_id: ln_test_utils::pubkey(46), encrypted_payload: Vec::new() }
6453 let mut route = Route { paths: vec![Path {
6454 hops: vec![RouteHop {
6455 pubkey: ln_test_utils::pubkey(42),
6456 node_features: NodeFeatures::empty(),
6457 short_channel_id: 42,
6458 channel_features: ChannelFeatures::empty(),
6460 cltv_expiry_delta: 0,
6463 pubkey: blinded_path.introduction_node_id,
6464 node_features: NodeFeatures::empty(),
6465 short_channel_id: 43,
6466 channel_features: ChannelFeatures::empty(),
6468 cltv_expiry_delta: 0,
6471 blinded_tail: Some(BlindedTail {
6472 hops: blinded_path.blinded_hops,
6473 blinding_point: blinded_path.blinding_point,
6474 excess_final_cltv_expiry_delta: 0,
6475 final_value_msat: 200,
6477 }], payment_params: None};
6479 let payment_params = PaymentParameters::from_node_id(ln_test_utils::pubkey(47), 18);
6480 let (_, network_graph, _, _, _) = build_line_graph();
6481 add_random_cltv_offset(&mut route, &payment_params, &network_graph.read_only(), &[0; 32]);
6482 assert_eq!(route.paths[0].blinded_tail.as_ref().unwrap().excess_final_cltv_expiry_delta, 40);
6483 assert_eq!(route.paths[0].hops.last().unwrap().cltv_expiry_delta, 40);
6487 fn simple_blinded_route_hints() {
6488 do_simple_blinded_route_hints(1);
6489 do_simple_blinded_route_hints(2);
6490 do_simple_blinded_route_hints(3);
6493 fn do_simple_blinded_route_hints(num_blinded_hops: usize) {
6494 // Check that we can generate a route to a blinded path with the expected hops.
6495 let (secp_ctx, network, _, _, logger) = build_graph();
6496 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6497 let network_graph = network.read_only();
6499 let scorer = ln_test_utils::TestScorer::new();
6500 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6501 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6503 let mut blinded_path = BlindedPath {
6504 introduction_node_id: nodes[2],
6505 blinding_point: ln_test_utils::pubkey(42),
6506 blinded_hops: Vec::with_capacity(num_blinded_hops),
6508 for i in 0..num_blinded_hops {
6509 blinded_path.blinded_hops.push(
6510 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 + i as u8), encrypted_payload: Vec::new() },
6513 let blinded_payinfo = BlindedPayInfo {
6515 fee_proportional_millionths: 500,
6516 htlc_minimum_msat: 1000,
6517 htlc_maximum_msat: 100_000_000,
6518 cltv_expiry_delta: 15,
6519 features: BlindedHopFeatures::empty(),
6522 let final_amt_msat = 1001;
6523 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), blinded_path.clone())]);
6524 let route = get_route(&our_id, &payment_params, &network_graph, None, final_amt_msat , Arc::clone(&logger),
6525 &scorer, &(), &random_seed_bytes).unwrap();
6526 assert_eq!(route.paths.len(), 1);
6527 assert_eq!(route.paths[0].hops.len(), 2);
6529 let tail = route.paths[0].blinded_tail.as_ref().unwrap();
6530 assert_eq!(tail.hops, blinded_path.blinded_hops);
6531 assert_eq!(tail.excess_final_cltv_expiry_delta, 0);
6532 assert_eq!(tail.final_value_msat, 1001);
6534 let final_hop = route.paths[0].hops.last().unwrap();
6535 assert_eq!(final_hop.pubkey, blinded_path.introduction_node_id);
6536 if tail.hops.len() > 1 {
6537 assert_eq!(final_hop.fee_msat,
6538 blinded_payinfo.fee_base_msat as u64 + blinded_payinfo.fee_proportional_millionths as u64 * tail.final_value_msat / 1000000);
6539 assert_eq!(final_hop.cltv_expiry_delta, blinded_payinfo.cltv_expiry_delta as u32);
6541 assert_eq!(final_hop.fee_msat, 0);
6542 assert_eq!(final_hop.cltv_expiry_delta, 0);
6547 fn blinded_path_routing_errors() {
6548 // Check that we can generate a route to a blinded path with the expected hops.
6549 let (secp_ctx, network, _, _, logger) = build_graph();
6550 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6551 let network_graph = network.read_only();
6553 let scorer = ln_test_utils::TestScorer::new();
6554 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6555 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6557 let mut invalid_blinded_path = BlindedPath {
6558 introduction_node_id: nodes[2],
6559 blinding_point: ln_test_utils::pubkey(42),
6561 BlindedHop { blinded_node_id: ln_test_utils::pubkey(43), encrypted_payload: vec![0; 43] },
6564 let blinded_payinfo = BlindedPayInfo {
6566 fee_proportional_millionths: 500,
6567 htlc_minimum_msat: 1000,
6568 htlc_maximum_msat: 100_000_000,
6569 cltv_expiry_delta: 15,
6570 features: BlindedHopFeatures::empty(),
6573 let mut invalid_blinded_path_2 = invalid_blinded_path.clone();
6574 invalid_blinded_path_2.introduction_node_id = ln_test_utils::pubkey(45);
6575 let payment_params = PaymentParameters::blinded(vec![
6576 (blinded_payinfo.clone(), invalid_blinded_path.clone()),
6577 (blinded_payinfo.clone(), invalid_blinded_path_2)]);
6578 match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
6579 &scorer, &(), &random_seed_bytes)
6581 Err(LightningError { err, .. }) => {
6582 assert_eq!(err, "1-hop blinded paths must all have matching introduction node ids");
6584 _ => panic!("Expected error")
6587 invalid_blinded_path.introduction_node_id = our_id;
6588 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo.clone(), invalid_blinded_path.clone())]);
6589 match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
6590 &scorer, &(), &random_seed_bytes)
6592 Err(LightningError { err, .. }) => {
6593 assert_eq!(err, "Cannot generate a route to blinded paths if we are the introduction node to all of them");
6595 _ => panic!("Expected error")
6598 invalid_blinded_path.introduction_node_id = ln_test_utils::pubkey(46);
6599 invalid_blinded_path.blinded_hops.clear();
6600 let payment_params = PaymentParameters::blinded(vec![(blinded_payinfo, invalid_blinded_path)]);
6601 match get_route(&our_id, &payment_params, &network_graph, None, 1001, Arc::clone(&logger),
6602 &scorer, &(), &random_seed_bytes)
6604 Err(LightningError { err, .. }) => {
6605 assert_eq!(err, "0-hop blinded path provided");
6607 _ => panic!("Expected error")
6612 fn matching_intro_node_paths_provided() {
6613 // Check that if multiple blinded paths with the same intro node are provided in payment
6614 // parameters, we'll return the correct paths in the resulting MPP route.
6615 let (secp_ctx, network, _, _, logger) = build_graph();
6616 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
6617 let network_graph = network.read_only();
6619 let scorer = ln_test_utils::TestScorer::new();
6620 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
6621 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6622 let config = UserConfig::default();
6624 let bolt12_features: Bolt12InvoiceFeatures = channelmanager::provided_invoice_features(&config).to_context();
6625 let blinded_path_1 = BlindedPath {
6626 introduction_node_id: nodes[2],
6627 blinding_point: ln_test_utils::pubkey(42),
6629 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() },
6630 BlindedHop { blinded_node_id: ln_test_utils::pubkey(42 as u8), encrypted_payload: Vec::new() }
6633 let blinded_payinfo_1 = BlindedPayInfo {
6635 fee_proportional_millionths: 0,
6636 htlc_minimum_msat: 0,
6637 htlc_maximum_msat: 30_000,
6638 cltv_expiry_delta: 0,
6639 features: BlindedHopFeatures::empty(),
6642 let mut blinded_path_2 = blinded_path_1.clone();
6643 blinded_path_2.blinding_point = ln_test_utils::pubkey(43);
6644 let mut blinded_payinfo_2 = blinded_payinfo_1.clone();
6645 blinded_payinfo_2.htlc_maximum_msat = 70_000;
6647 let blinded_hints = vec![
6648 (blinded_payinfo_1.clone(), blinded_path_1.clone()),
6649 (blinded_payinfo_2.clone(), blinded_path_2.clone()),
6651 let payment_params = PaymentParameters::blinded(blinded_hints.clone())
6652 .with_bolt12_features(bolt12_features.clone()).unwrap();
6654 let route = get_route(&our_id, &payment_params, &network_graph, None,
6655 100_000, Arc::clone(&logger), &scorer, &(), &random_seed_bytes).unwrap();
6656 assert_eq!(route.paths.len(), 2);
6657 let mut total_amount_paid_msat = 0;
6658 for path in route.paths.into_iter() {
6659 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
6660 if let Some(bt) = &path.blinded_tail {
6661 assert_eq!(bt.blinding_point,
6662 blinded_hints.iter().find(|(p, _)| p.htlc_maximum_msat == path.final_value_msat())
6663 .map(|(_, bp)| bp.blinding_point).unwrap());
6664 } else { panic!(); }
6665 total_amount_paid_msat += path.final_value_msat();
6667 assert_eq!(total_amount_paid_msat, 100_000);
6671 #[cfg(all(any(test, ldk_bench), not(feature = "no-std")))]
6672 pub(crate) mod bench_utils {
6676 use bitcoin::hashes::Hash;
6677 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
6679 use crate::chain::transaction::OutPoint;
6680 use crate::sign::{EntropySource, KeysManager};
6681 use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
6682 use crate::ln::features::Bolt11InvoiceFeatures;
6683 use crate::routing::gossip::NetworkGraph;
6684 use crate::util::config::UserConfig;
6685 use crate::util::ser::ReadableArgs;
6686 use crate::util::test_utils::TestLogger;
6688 /// Tries to open a network graph file, or panics with a URL to fetch it.
6689 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
6690 let res = File::open("net_graph-2023-01-18.bin") // By default we're run in RL/lightning
6691 .or_else(|_| File::open("lightning/net_graph-2023-01-18.bin")) // We may be run manually in RL/
6692 .or_else(|_| { // Fall back to guessing based on the binary location
6693 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
6694 let mut path = std::env::current_exe().unwrap();
6695 path.pop(); // lightning-...
6697 path.pop(); // debug
6698 path.pop(); // target
6699 path.push("lightning");
6700 path.push("net_graph-2023-01-18.bin");
6703 .or_else(|_| { // Fall back to guessing based on the binary location for a subcrate
6704 // path is likely something like .../rust-lightning/bench/target/debug/deps/bench..
6705 let mut path = std::env::current_exe().unwrap();
6706 path.pop(); // bench...
6708 path.pop(); // debug
6709 path.pop(); // target
6710 path.pop(); // bench
6711 path.push("lightning");
6712 path.push("net_graph-2023-01-18.bin");
6715 .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");
6716 #[cfg(require_route_graph_test)]
6717 return Ok(res.unwrap());
6718 #[cfg(not(require_route_graph_test))]
6722 pub(crate) fn read_network_graph(logger: &TestLogger) -> Result<NetworkGraph<&TestLogger>, &'static str> {
6723 get_route_file().map(|mut f| NetworkGraph::read(&mut f, logger).unwrap())
6726 pub(crate) fn payer_pubkey() -> PublicKey {
6727 let secp_ctx = Secp256k1::new();
6728 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
6732 pub(crate) fn first_hop(node_id: PublicKey) -> ChannelDetails {
6734 channel_id: [0; 32],
6735 counterparty: ChannelCounterparty {
6736 features: channelmanager::provided_init_features(&UserConfig::default()),
6738 unspendable_punishment_reserve: 0,
6739 forwarding_info: None,
6740 outbound_htlc_minimum_msat: None,
6741 outbound_htlc_maximum_msat: None,
6743 funding_txo: Some(OutPoint {
6744 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
6747 short_channel_id: Some(1),
6748 inbound_scid_alias: None,
6749 outbound_scid_alias: None,
6750 channel_value_satoshis: 10_000_000_000,
6752 balance_msat: 10_000_000_000,
6753 outbound_capacity_msat: 10_000_000_000,
6754 next_outbound_htlc_minimum_msat: 0,
6755 next_outbound_htlc_limit_msat: 10_000_000_000,
6756 inbound_capacity_msat: 0,
6757 unspendable_punishment_reserve: None,
6758 confirmations_required: None,
6759 confirmations: None,
6760 force_close_spend_delay: None,
6762 is_channel_ready: true,
6765 inbound_htlc_minimum_msat: None,
6766 inbound_htlc_maximum_msat: None,
6768 feerate_sat_per_1000_weight: None,
6769 channel_shutdown_state: Some(channelmanager::ChannelShutdownState::NotShuttingDown),
6773 pub(crate) fn generate_test_routes<S: Score>(graph: &NetworkGraph<&TestLogger>, scorer: &mut S,
6774 score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, mut seed: u64,
6775 starting_amount: u64, route_count: usize,
6776 ) -> Vec<(ChannelDetails, PaymentParameters, u64)> {
6777 let payer = payer_pubkey();
6778 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6779 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6781 let nodes = graph.read_only().nodes().clone();
6782 let mut route_endpoints = Vec::new();
6783 // Fetch 1.5x more routes than we need as after we do some scorer updates we may end up
6784 // with some routes we picked being un-routable.
6785 for _ in 0..route_count * 3 / 2 {
6787 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6788 let src = PublicKey::from_slice(nodes.unordered_keys()
6789 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
6790 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6791 let dst = PublicKey::from_slice(nodes.unordered_keys()
6792 .skip((seed as usize) % nodes.len()).next().unwrap().as_slice()).unwrap();
6793 let params = PaymentParameters::from_node_id(dst, 42)
6794 .with_bolt11_features(features.clone()).unwrap();
6795 let first_hop = first_hop(src);
6796 let amt = starting_amount + seed % 1_000_000;
6798 get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]),
6799 amt, &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok();
6801 // ...and seed the scorer with success and failure data...
6802 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6803 let mut score_amt = seed % 1_000_000_000;
6805 // Generate fail/success paths for a wider range of potential amounts with
6806 // MPP enabled to give us a chance to apply penalties for more potential
6808 let mpp_features = channelmanager::provided_invoice_features(&UserConfig::default());
6809 let params = PaymentParameters::from_node_id(dst, 42)
6810 .with_bolt11_features(mpp_features).unwrap();
6812 let route_res = get_route(&payer, ¶ms, &graph.read_only(),
6813 Some(&[&first_hop]), score_amt, &TestLogger::new(), &scorer,
6814 score_params, &random_seed_bytes);
6815 if let Ok(route) = route_res {
6816 for path in route.paths {
6817 if seed & 0x80 == 0 {
6818 scorer.payment_path_successful(&path);
6820 let short_channel_id = path.hops[path.hops.len() / 2].short_channel_id;
6821 scorer.payment_path_failed(&path, short_channel_id);
6823 seed = seed.overflowing_mul(6364136223846793005).0.overflowing_add(1).0;
6827 // If we couldn't find a path with a higer amount, reduce and try again.
6831 route_endpoints.push((first_hop, params, amt));
6837 // Because we've changed channel scores, it's possible we'll take different routes to the
6838 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
6839 // requires a too-high CLTV delta.
6840 route_endpoints.retain(|(first_hop, params, amt)| {
6841 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
6842 &TestLogger::new(), &scorer, score_params, &random_seed_bytes).is_ok()
6844 route_endpoints.truncate(route_count);
6845 assert_eq!(route_endpoints.len(), route_count);
6853 use crate::sign::{EntropySource, KeysManager};
6854 use crate::ln::channelmanager;
6855 use crate::ln::features::Bolt11InvoiceFeatures;
6856 use crate::routing::gossip::NetworkGraph;
6857 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringFeeParameters, ProbabilisticScoringDecayParameters};
6858 use crate::util::config::UserConfig;
6859 use crate::util::logger::{Logger, Record};
6860 use crate::util::test_utils::TestLogger;
6862 use criterion::Criterion;
6864 struct DummyLogger {}
6865 impl Logger for DummyLogger {
6866 fn log(&self, _record: &Record) {}
6869 pub fn generate_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
6870 let logger = TestLogger::new();
6871 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6872 let scorer = FixedPenaltyScorer::with_penalty(0);
6873 generate_routes(bench, &network_graph, scorer, &(), Bolt11InvoiceFeatures::empty(), 0,
6874 "generate_routes_with_zero_penalty_scorer");
6877 pub fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Criterion) {
6878 let logger = TestLogger::new();
6879 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6880 let scorer = FixedPenaltyScorer::with_penalty(0);
6881 generate_routes(bench, &network_graph, scorer, &(),
6882 channelmanager::provided_invoice_features(&UserConfig::default()), 0,
6883 "generate_mpp_routes_with_zero_penalty_scorer");
6886 pub fn generate_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6887 let logger = TestLogger::new();
6888 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6889 let params = ProbabilisticScoringFeeParameters::default();
6890 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6891 generate_routes(bench, &network_graph, scorer, ¶ms, Bolt11InvoiceFeatures::empty(), 0,
6892 "generate_routes_with_probabilistic_scorer");
6895 pub fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6896 let logger = TestLogger::new();
6897 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6898 let params = ProbabilisticScoringFeeParameters::default();
6899 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6900 generate_routes(bench, &network_graph, scorer, ¶ms,
6901 channelmanager::provided_invoice_features(&UserConfig::default()), 0,
6902 "generate_mpp_routes_with_probabilistic_scorer");
6905 pub fn generate_large_mpp_routes_with_probabilistic_scorer(bench: &mut Criterion) {
6906 let logger = TestLogger::new();
6907 let network_graph = bench_utils::read_network_graph(&logger).unwrap();
6908 let params = ProbabilisticScoringFeeParameters::default();
6909 let scorer = ProbabilisticScorer::new(ProbabilisticScoringDecayParameters::default(), &network_graph, &logger);
6910 generate_routes(bench, &network_graph, scorer, ¶ms,
6911 channelmanager::provided_invoice_features(&UserConfig::default()), 100_000_000,
6912 "generate_large_mpp_routes_with_probabilistic_scorer");
6915 fn generate_routes<S: Score>(
6916 bench: &mut Criterion, graph: &NetworkGraph<&TestLogger>, mut scorer: S,
6917 score_params: &S::ScoreParams, features: Bolt11InvoiceFeatures, starting_amount: u64,
6918 bench_name: &'static str,
6920 let payer = bench_utils::payer_pubkey();
6921 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6922 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6924 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
6925 let route_endpoints = bench_utils::generate_test_routes(graph, &mut scorer, score_params, features, 0xdeadbeef, starting_amount, 50);
6927 // ...then benchmark finding paths between the nodes we learned.
6929 bench.bench_function(bench_name, |b| b.iter(|| {
6930 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
6931 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt,
6932 &DummyLogger{}, &scorer, score_params, &random_seed_bytes).is_ok());