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::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
20 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
21 use crate::offers::invoice::BlindedPayInfo;
22 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
23 use crate::routing::scoring::{ChannelUsage, LockableScore, Score};
24 use crate::util::ser::{Writeable, Readable, ReadableArgs, Writer};
25 use crate::util::logger::{Level, Logger};
26 use crate::util::chacha20::ChaCha20;
29 use crate::prelude::*;
30 use crate::sync::Mutex;
31 use alloc::collections::BinaryHeap;
35 /// A [`Router`] implemented using [`find_route`].
36 pub struct DefaultRouter<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> where
38 S::Target: for <'a> LockableScore<'a>,
42 random_seed_bytes: Mutex<[u8; 32]>,
46 impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> DefaultRouter<G, L, S> where
48 S::Target: for <'a> LockableScore<'a>,
50 /// Creates a new router.
51 pub fn new(network_graph: G, logger: L, random_seed_bytes: [u8; 32], scorer: S) -> Self {
52 let random_seed_bytes = Mutex::new(random_seed_bytes);
53 Self { network_graph, logger, random_seed_bytes, scorer }
57 impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultRouter<G, L, S> where
59 S::Target: for <'a> LockableScore<'a>,
62 &self, payer: &PublicKey, params: &RouteParameters, first_hops: Option<&[&ChannelDetails]>,
63 inflight_htlcs: &InFlightHtlcs
64 ) -> Result<Route, LightningError> {
65 let random_seed_bytes = {
66 let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
67 *locked_random_seed_bytes = Sha256::hash(&*locked_random_seed_bytes).into_inner();
68 *locked_random_seed_bytes
72 payer, params, &self.network_graph, first_hops, &*self.logger,
73 &ScorerAccountingForInFlightHtlcs::new(self.scorer.lock(), inflight_htlcs),
79 /// A trait defining behavior for routing a payment.
81 /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
83 &self, payer: &PublicKey, route_params: &RouteParameters,
84 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
85 ) -> Result<Route, LightningError>;
86 /// Finds a [`Route`] between `payer` and `payee` for a payment with the given values. Includes
87 /// `PaymentHash` and `PaymentId` to be able to correlate the request with a specific payment.
88 fn find_route_with_id(
89 &self, payer: &PublicKey, route_params: &RouteParameters,
90 first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs,
91 _payment_hash: PaymentHash, _payment_id: PaymentId
92 ) -> Result<Route, LightningError> {
93 self.find_route(payer, route_params, first_hops, inflight_htlcs)
97 /// [`Score`] implementation that factors in in-flight HTLC liquidity.
99 /// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
102 /// [`Score`]: crate::routing::scoring::Score
103 pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score> {
105 // Maps a channel's short channel id and its direction to the liquidity used up.
106 inflight_htlcs: &'a InFlightHtlcs,
109 impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
110 /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
111 pub fn new(scorer: S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
112 ScorerAccountingForInFlightHtlcs {
120 impl<'a, S: Score> Writeable for ScorerAccountingForInFlightHtlcs<'a, S> {
121 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
124 impl<'a, S: Score> Score for ScorerAccountingForInFlightHtlcs<'a, S> {
125 fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage) -> u64 {
126 if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
127 source, target, short_channel_id
129 let usage = ChannelUsage {
130 inflight_htlc_msat: usage.inflight_htlc_msat + used_liquidity,
134 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage)
136 self.scorer.channel_penalty_msat(short_channel_id, source, target, usage)
140 fn payment_path_failed(&mut self, path: &Path, short_channel_id: u64) {
141 self.scorer.payment_path_failed(path, short_channel_id)
144 fn payment_path_successful(&mut self, path: &Path) {
145 self.scorer.payment_path_successful(path)
148 fn probe_failed(&mut self, path: &Path, short_channel_id: u64) {
149 self.scorer.probe_failed(path, short_channel_id)
152 fn probe_successful(&mut self, path: &Path) {
153 self.scorer.probe_successful(path)
157 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
158 /// in-use channel liquidity.
160 pub struct InFlightHtlcs(
161 // A map with liquidity value (in msat) keyed by a short channel id and the direction the HTLC
162 // is traveling in. The direction boolean is determined by checking if the HTLC source's public
163 // key is less than its destination. See `InFlightHtlcs::used_liquidity_msat` for more
165 HashMap<(u64, bool), u64>
169 /// Constructs an empty `InFlightHtlcs`.
170 pub fn new() -> Self { InFlightHtlcs(HashMap::new()) }
172 /// Takes in a path with payer's node id and adds the path's details to `InFlightHtlcs`.
173 pub fn process_path(&mut self, path: &Path, payer_node_id: PublicKey) {
174 if path.hops.is_empty() { return };
176 let mut cumulative_msat = 0;
177 if let Some(tail) = &path.blinded_tail {
178 cumulative_msat += tail.final_value_msat;
181 // total_inflight_map needs to be direction-sensitive when keeping track of the HTLC value
182 // that is held up. However, the `hops` array, which is a path returned by `find_route` in
183 // the router excludes the payer node. In the following lines, the payer's information is
184 // hardcoded with an inflight value of 0 so that we can correctly represent the first hop
185 // in our sliding window of two.
186 let reversed_hops_with_payer = path.hops.iter().rev().skip(1)
187 .map(|hop| hop.pubkey)
188 .chain(core::iter::once(payer_node_id));
190 // Taking the reversed vector from above, we zip it with just the reversed hops list to
191 // work "backwards" of the given path, since the last hop's `fee_msat` actually represents
192 // the total amount sent.
193 for (next_hop, prev_hop) in path.hops.iter().rev().zip(reversed_hops_with_payer) {
194 cumulative_msat += next_hop.fee_msat;
196 .entry((next_hop.short_channel_id, NodeId::from_pubkey(&prev_hop) < NodeId::from_pubkey(&next_hop.pubkey)))
197 .and_modify(|used_liquidity_msat| *used_liquidity_msat += cumulative_msat)
198 .or_insert(cumulative_msat);
202 /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
204 pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
205 self.0.get(&(channel_scid, source < target)).map(|v| *v)
209 impl Writeable for InFlightHtlcs {
210 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
213 impl Readable for InFlightHtlcs {
214 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
215 let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
216 Ok(Self(infight_map))
220 /// A hop in a route, and additional metadata about it. "Hop" is defined as a node and the channel
221 /// that leads to it.
222 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
223 pub struct RouteHop {
224 /// The node_id of the node at this hop.
225 pub pubkey: PublicKey,
226 /// The node_announcement features of the node at this hop. For the last hop, these may be
227 /// amended to match the features present in the invoice this node generated.
228 pub node_features: NodeFeatures,
229 /// The channel that should be used from the previous hop to reach this node.
230 pub short_channel_id: u64,
231 /// The channel_announcement features of the channel that should be used from the previous hop
232 /// to reach this node.
233 pub channel_features: ChannelFeatures,
234 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
235 /// If this is the last hop in [`Path::hops`]:
236 /// * if we're sending to a [`BlindedPath`], this is the fee paid for use of the entire blinded path
237 /// * otherwise, this is the full value of this [`Path`]'s part of the payment
239 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
241 /// The CLTV delta added for this hop.
242 /// If this is the last hop in [`Path::hops`]:
243 /// * if we're sending to a [`BlindedPath`], this is the CLTV delta for the entire blinded path
244 /// * otherwise, this is the CLTV delta expected at the destination
246 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
247 pub cltv_expiry_delta: u32,
250 impl_writeable_tlv_based!(RouteHop, {
251 (0, pubkey, required),
252 (2, node_features, required),
253 (4, short_channel_id, required),
254 (6, channel_features, required),
255 (8, fee_msat, required),
256 (10, cltv_expiry_delta, required),
259 /// The blinded portion of a [`Path`], if we're routing to a recipient who provided blinded paths in
260 /// their BOLT12 [`Invoice`].
262 /// [`Invoice`]: crate::offers::invoice::Invoice
263 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
264 pub struct BlindedTail {
265 /// The hops of the [`BlindedPath`] provided by the recipient.
267 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
268 pub hops: Vec<BlindedHop>,
269 /// The blinding point of the [`BlindedPath`] provided by the recipient.
271 /// [`BlindedPath`]: crate::blinded_path::BlindedPath
272 pub blinding_point: PublicKey,
273 /// Excess CLTV delta added to the recipient's CLTV expiry to deter intermediate nodes from
274 /// inferring the destination. May be 0.
275 pub excess_final_cltv_expiry_delta: u32,
276 /// The total amount paid on this [`Path`], excluding the fees.
277 pub final_value_msat: u64,
280 impl_writeable_tlv_based!(BlindedTail, {
282 (2, blinding_point, required),
283 (4, excess_final_cltv_expiry_delta, required),
284 (6, final_value_msat, required),
287 /// A path in a [`Route`] to the payment recipient. Must always be at least length one.
288 /// If no [`Path::blinded_tail`] is present, then [`Path::hops`] length may be up to 19.
289 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
291 /// The list of unblinded hops in this [`Path`]. Must be at least length one.
292 pub hops: Vec<RouteHop>,
293 /// The blinded path at which this path terminates, if we're sending to one, and its metadata.
294 pub blinded_tail: Option<BlindedTail>,
298 /// Gets the fees for a given path, excluding any excess paid to the recipient.
299 pub fn fee_msat(&self) -> u64 {
300 match &self.blinded_tail {
301 Some(_) => self.hops.iter().map(|hop| hop.fee_msat).sum::<u64>(),
303 // Do not count last hop of each path since that's the full value of the payment
304 self.hops.split_last().map_or(0,
305 |(_, path_prefix)| path_prefix.iter().map(|hop| hop.fee_msat).sum())
310 /// Gets the total amount paid on this [`Path`], excluding the fees.
311 pub fn final_value_msat(&self) -> u64 {
312 match &self.blinded_tail {
313 Some(blinded_tail) => blinded_tail.final_value_msat,
314 None => self.hops.last().map_or(0, |hop| hop.fee_msat)
318 /// Gets the final hop's CLTV expiry delta.
319 pub fn final_cltv_expiry_delta(&self) -> Option<u32> {
320 match &self.blinded_tail {
322 None => self.hops.last().map(|hop| hop.cltv_expiry_delta)
327 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
328 /// it can take multiple paths. Each path is composed of one or more hops through the network.
329 #[derive(Clone, Hash, PartialEq, Eq)]
331 /// The list of [`Path`]s taken for a single (potentially-)multi-part payment. If no
332 /// [`BlindedTail`]s are present, then the pubkey of the last [`RouteHop`] in each path must be
334 pub paths: Vec<Path>,
335 /// The `payment_params` parameter passed to [`find_route`].
336 /// This is used by `ChannelManager` to track information which may be required for retries,
337 /// provided back to you via [`Event::PaymentPathFailed`].
339 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
340 pub payment_params: Option<PaymentParameters>,
344 /// Returns the total amount of fees paid on this [`Route`].
346 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
347 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
348 pub fn get_total_fees(&self) -> u64 {
349 self.paths.iter().map(|path| path.fee_msat()).sum()
352 /// Returns the total amount paid on this [`Route`], excluding the fees. Might be more than
353 /// requested if we had to reach htlc_minimum_msat.
354 pub fn get_total_amount(&self) -> u64 {
355 self.paths.iter().map(|path| path.final_value_msat()).sum()
359 const SERIALIZATION_VERSION: u8 = 1;
360 const MIN_SERIALIZATION_VERSION: u8 = 1;
362 impl Writeable for Route {
363 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
364 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
365 (self.paths.len() as u64).write(writer)?;
366 let mut blinded_tails = Vec::new();
367 for path in self.paths.iter() {
368 (path.hops.len() as u8).write(writer)?;
369 for (idx, hop) in path.hops.iter().enumerate() {
371 if let Some(blinded_tail) = &path.blinded_tail {
372 if blinded_tails.is_empty() {
373 blinded_tails = Vec::with_capacity(path.hops.len());
375 blinded_tails.push(None);
378 blinded_tails.push(Some(blinded_tail));
379 } else if !blinded_tails.is_empty() { blinded_tails.push(None); }
382 write_tlv_fields!(writer, {
383 (1, self.payment_params, option),
384 (2, blinded_tails, optional_vec),
390 impl Readable for Route {
391 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
392 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
393 let path_count: u64 = Readable::read(reader)?;
394 if path_count == 0 { return Err(DecodeError::InvalidValue); }
395 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
396 let mut min_final_cltv_expiry_delta = u32::max_value();
397 for _ in 0..path_count {
398 let hop_count: u8 = Readable::read(reader)?;
399 let mut hops: Vec<RouteHop> = Vec::with_capacity(hop_count as usize);
400 for _ in 0..hop_count {
401 hops.push(Readable::read(reader)?);
403 if hops.is_empty() { return Err(DecodeError::InvalidValue); }
404 min_final_cltv_expiry_delta =
405 cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
406 paths.push(Path { hops, blinded_tail: None });
408 _init_and_read_tlv_fields!(reader, {
409 (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
410 (2, blinded_tails, optional_vec),
412 let blinded_tails = blinded_tails.unwrap_or(Vec::new());
413 if blinded_tails.len() != 0 {
414 if blinded_tails.len() != paths.len() { return Err(DecodeError::InvalidValue) }
415 for (mut path, blinded_tail_opt) in paths.iter_mut().zip(blinded_tails.into_iter()) {
416 path.blinded_tail = blinded_tail_opt;
419 Ok(Route { paths, payment_params })
423 /// Parameters needed to find a [`Route`].
425 /// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
426 /// [`Event::PaymentPathFailed`].
428 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
429 #[derive(Clone, Debug, PartialEq, Eq)]
430 pub struct RouteParameters {
431 /// The parameters of the failed payment path.
432 pub payment_params: PaymentParameters,
434 /// The amount in msats sent on the failed payment path.
435 pub final_value_msat: u64,
438 impl Writeable for RouteParameters {
439 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
440 write_tlv_fields!(writer, {
441 (0, self.payment_params, required),
442 (2, self.final_value_msat, required),
443 // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
444 // `RouteParameters` directly. For compatibility, we write it here.
445 (4, self.payment_params.final_cltv_expiry_delta, required),
451 impl Readable for RouteParameters {
452 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
453 _init_and_read_tlv_fields!(reader, {
454 (0, payment_params, (required: ReadableArgs, 0)),
455 (2, final_value_msat, required),
456 (4, final_cltv_expiry_delta, required),
458 let mut payment_params: PaymentParameters = payment_params.0.unwrap();
459 if payment_params.final_cltv_expiry_delta == 0 {
460 payment_params.final_cltv_expiry_delta = final_cltv_expiry_delta.0.unwrap();
464 final_value_msat: final_value_msat.0.unwrap(),
469 /// Maximum total CTLV difference we allow for a full payment path.
470 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
472 /// Maximum number of paths we allow an (MPP) payment to have.
473 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
474 // limits, but for now more than 10 paths likely carries too much one-path failure.
475 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
477 // The median hop CLTV expiry delta currently seen in the network.
478 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
480 // During routing, we only consider paths shorter than our maximum length estimate.
481 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
482 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
483 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
485 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
486 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
487 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
488 // (payment_secret and total_msat) = 93 bytes for the final hop.
489 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
490 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
491 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
493 /// The recipient of a payment.
494 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
495 pub struct PaymentParameters {
496 /// The node id of the payee.
497 pub payee_pubkey: PublicKey,
499 /// Features supported by the payee.
501 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
502 /// does not contain any features.
504 /// [`for_keysend`]: Self::for_keysend
505 pub features: Option<InvoiceFeatures>,
507 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
508 pub route_hints: Hints,
510 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
511 pub expiry_time: Option<u64>,
513 /// The maximum total CLTV delta we accept for the route.
514 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
515 pub max_total_cltv_expiry_delta: u32,
517 /// The maximum number of paths that may be used by (MPP) payments.
518 /// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
519 pub max_path_count: u8,
521 /// Selects the maximum share of a channel's total capacity which will be sent over a channel,
522 /// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
523 /// a lower value prefers to send larger MPP parts, potentially saturating channels and
524 /// increasing failure probability for those paths.
526 /// Note that this restriction will be relaxed during pathfinding after paths which meet this
527 /// restriction have been found. While paths which meet this criteria will be searched for, it
528 /// is ultimately up to the scorer to select them over other paths.
530 /// A value of 0 will allow payments up to and including a channel's total announced usable
531 /// capacity, a value of one will only use up to half its capacity, two 1/4, etc.
534 pub max_channel_saturation_power_of_half: u8,
536 /// A list of SCIDs which this payment was previously attempted over and which caused the
537 /// payment to fail. Future attempts for the same payment shouldn't be relayed through any of
539 pub previously_failed_channels: Vec<u64>,
541 /// The minimum CLTV delta at the end of the route. This value must not be zero.
542 pub final_cltv_expiry_delta: u32,
545 impl Writeable for PaymentParameters {
546 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
547 let mut clear_hints = &vec![];
548 let mut blinded_hints = &vec![];
549 match &self.route_hints {
550 Hints::Clear(hints) => clear_hints = hints,
551 Hints::Blinded(hints) => blinded_hints = hints,
553 write_tlv_fields!(writer, {
554 (0, self.payee_pubkey, required),
555 (1, self.max_total_cltv_expiry_delta, required),
556 (2, self.features, option),
557 (3, self.max_path_count, required),
558 (4, *clear_hints, vec_type),
559 (5, self.max_channel_saturation_power_of_half, required),
560 (6, self.expiry_time, option),
561 (7, self.previously_failed_channels, vec_type),
562 (8, *blinded_hints, optional_vec),
563 (9, self.final_cltv_expiry_delta, required),
569 impl ReadableArgs<u32> for PaymentParameters {
570 fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
571 _init_and_read_tlv_fields!(reader, {
572 (0, payee_pubkey, required),
573 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
574 (2, features, option),
575 (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
576 (4, route_hints, vec_type),
577 (5, max_channel_saturation_power_of_half, (default_value, 2)),
578 (6, expiry_time, option),
579 (7, previously_failed_channels, vec_type),
580 (8, blinded_route_hints, optional_vec),
581 (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
583 let clear_route_hints = route_hints.unwrap_or(vec![]);
584 let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
585 let route_hints = if blinded_route_hints.len() != 0 {
586 if clear_route_hints.len() != 0 { return Err(DecodeError::InvalidValue) }
587 Hints::Blinded(blinded_route_hints)
589 Hints::Clear(clear_route_hints)
592 payee_pubkey: _init_tlv_based_struct_field!(payee_pubkey, required),
593 max_total_cltv_expiry_delta: _init_tlv_based_struct_field!(max_total_cltv_expiry_delta, (default_value, unused)),
595 max_path_count: _init_tlv_based_struct_field!(max_path_count, (default_value, unused)),
597 max_channel_saturation_power_of_half: _init_tlv_based_struct_field!(max_channel_saturation_power_of_half, (default_value, unused)),
599 previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
600 final_cltv_expiry_delta: _init_tlv_based_struct_field!(final_cltv_expiry_delta, (default_value, unused)),
606 impl PaymentParameters {
607 /// Creates a payee with the node id of the given `pubkey`.
609 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
611 pub fn from_node_id(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
615 route_hints: Hints::Clear(vec![]),
617 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
618 max_path_count: DEFAULT_MAX_PATH_COUNT,
619 max_channel_saturation_power_of_half: 2,
620 previously_failed_channels: Vec::new(),
621 final_cltv_expiry_delta,
625 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
627 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
629 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
630 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta).with_features(InvoiceFeatures::for_keysend())
633 /// Includes the payee's features.
635 /// This is not exported to bindings users since bindings don't support move semantics
636 pub fn with_features(self, features: InvoiceFeatures) -> Self {
637 Self { features: Some(features), ..self }
640 /// Includes hints for routing to the payee.
642 /// This is not exported to bindings users since bindings don't support move semantics
643 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
644 Self { route_hints: Hints::Clear(route_hints), ..self }
647 /// Includes a payment expiration in seconds relative to the UNIX epoch.
649 /// This is not exported to bindings users since bindings don't support move semantics
650 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
651 Self { expiry_time: Some(expiry_time), ..self }
654 /// Includes a limit for the total CLTV expiry delta which is considered during routing
656 /// This is not exported to bindings users since bindings don't support move semantics
657 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
658 Self { max_total_cltv_expiry_delta, ..self }
661 /// Includes a limit for the maximum number of payment paths that may be used.
663 /// This is not exported to bindings users since bindings don't support move semantics
664 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
665 Self { max_path_count, ..self }
668 /// Includes a limit for the maximum number of payment paths that may be used.
670 /// This is not exported to bindings users since bindings don't support move semantics
671 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
672 Self { max_channel_saturation_power_of_half, ..self }
676 /// Routing hints for the tail of the route.
677 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
679 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
680 /// will be included in the final [`Route`].
681 Blinded(Vec<(BlindedPayInfo, BlindedPath)>),
682 /// The recipient included these route hints in their BOLT11 invoice.
683 Clear(Vec<RouteHint>),
686 /// A list of hops along a payment path terminating with a channel to the recipient.
687 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
688 pub struct RouteHint(pub Vec<RouteHintHop>);
690 impl Writeable for RouteHint {
691 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
692 (self.0.len() as u64).write(writer)?;
693 for hop in self.0.iter() {
700 impl Readable for RouteHint {
701 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
702 let hop_count: u64 = Readable::read(reader)?;
703 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
704 for _ in 0..hop_count {
705 hops.push(Readable::read(reader)?);
711 /// A channel descriptor for a hop along a payment path.
712 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
713 pub struct RouteHintHop {
714 /// The node_id of the non-target end of the route
715 pub src_node_id: PublicKey,
716 /// The short_channel_id of this channel
717 pub short_channel_id: u64,
718 /// The fees which must be paid to use this channel
719 pub fees: RoutingFees,
720 /// The difference in CLTV values between this node and the next node.
721 pub cltv_expiry_delta: u16,
722 /// The minimum value, in msat, which must be relayed to the next hop.
723 pub htlc_minimum_msat: Option<u64>,
724 /// The maximum value in msat available for routing with a single HTLC.
725 pub htlc_maximum_msat: Option<u64>,
728 impl_writeable_tlv_based!(RouteHintHop, {
729 (0, src_node_id, required),
730 (1, htlc_minimum_msat, option),
731 (2, short_channel_id, required),
732 (3, htlc_maximum_msat, option),
734 (6, cltv_expiry_delta, required),
737 #[derive(Eq, PartialEq)]
738 struct RouteGraphNode {
740 lowest_fee_to_node: u64,
741 total_cltv_delta: u32,
742 // The maximum value a yet-to-be-constructed payment path might flow through this node.
743 // This value is upper-bounded by us by:
744 // - how much is needed for a path being constructed
745 // - how much value can channels following this node (up to the destination) can contribute,
746 // considering their capacity and fees
747 value_contribution_msat: u64,
748 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
749 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
750 path_htlc_minimum_msat: u64,
751 /// All penalties incurred from this hop on the way to the destination, as calculated using
753 path_penalty_msat: u64,
754 /// The number of hops walked up to this node.
755 path_length_to_node: u8,
758 impl cmp::Ord for RouteGraphNode {
759 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
760 let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat)
761 .saturating_add(other.path_penalty_msat);
762 let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat)
763 .saturating_add(self.path_penalty_msat);
764 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
768 impl cmp::PartialOrd for RouteGraphNode {
769 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
770 Some(self.cmp(other))
774 /// A wrapper around the various hop representations.
776 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
777 #[derive(Clone, Debug)]
778 enum CandidateRouteHop<'a> {
779 /// A hop from the payer, where the outbound liquidity is known.
781 details: &'a ChannelDetails,
783 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
785 info: DirectedChannelInfo<'a>,
786 short_channel_id: u64,
788 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
790 hint: &'a RouteHintHop,
794 impl<'a> CandidateRouteHop<'a> {
795 fn short_channel_id(&self) -> u64 {
797 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
798 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
799 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
803 // NOTE: This may alloc memory so avoid calling it in a hot code path.
804 fn features(&self) -> ChannelFeatures {
806 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
807 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
808 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
812 fn cltv_expiry_delta(&self) -> u32 {
814 CandidateRouteHop::FirstHop { .. } => 0,
815 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
816 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
820 fn htlc_minimum_msat(&self) -> u64 {
822 CandidateRouteHop::FirstHop { .. } => 0,
823 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
824 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
828 fn fees(&self) -> RoutingFees {
830 CandidateRouteHop::FirstHop { .. } => RoutingFees {
831 base_msat: 0, proportional_millionths: 0,
833 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
834 CandidateRouteHop::PrivateHop { hint } => hint.fees,
838 fn effective_capacity(&self) -> EffectiveCapacity {
840 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
841 liquidity_msat: details.next_outbound_htlc_limit_msat,
843 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
844 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
850 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
851 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
853 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
854 EffectiveCapacity::Infinite => u64::max_value(),
855 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
856 EffectiveCapacity::MaximumHTLC { amount_msat } =>
857 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
858 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
859 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
863 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
864 -> bool where I1::Item: PartialEq<I2::Item> {
866 let a = iter_a.next();
867 let b = iter_b.next();
868 if a.is_none() && b.is_none() { return true; }
869 if a.is_none() || b.is_none() { return false; }
870 if a.unwrap().ne(&b.unwrap()) { return false; }
874 /// It's useful to keep track of the hops associated with the fees required to use them,
875 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
876 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
877 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
879 struct PathBuildingHop<'a> {
880 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
881 // is a larger refactor and will require careful performance analysis.
883 candidate: CandidateRouteHop<'a>,
886 /// All the fees paid *after* this channel on the way to the destination
887 next_hops_fee_msat: u64,
888 /// Fee paid for the use of the current channel (see candidate.fees()).
889 /// The value will be actually deducted from the counterparty balance on the previous link.
890 hop_use_fee_msat: u64,
891 /// Used to compare channels when choosing the for routing.
892 /// Includes paying for the use of a hop and the following hops, as well as
893 /// an estimated cost of reaching this hop.
894 /// Might get stale when fees are recomputed. Primarily for internal use.
896 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
897 /// walk and may be invalid thereafter.
898 path_htlc_minimum_msat: u64,
899 /// All penalties incurred from this channel on the way to the destination, as calculated using
901 path_penalty_msat: u64,
902 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
903 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
904 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
905 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
906 /// avoid processing them again.
908 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
909 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
910 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
911 // value_contribution_msat, which requires tracking it here. See comments below where it is
912 // used for more info.
913 value_contribution_msat: u64,
916 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
917 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
918 let mut debug_struct = f.debug_struct("PathBuildingHop");
920 .field("node_id", &self.node_id)
921 .field("short_channel_id", &self.candidate.short_channel_id())
922 .field("total_fee_msat", &self.total_fee_msat)
923 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
924 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
925 .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)))
926 .field("path_penalty_msat", &self.path_penalty_msat)
927 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
928 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
929 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
930 let debug_struct = debug_struct
931 .field("value_contribution_msat", &self.value_contribution_msat);
932 debug_struct.finish()
936 // Instantiated with a list of hops with correct data in them collected during path finding,
937 // an instance of this struct should be further modified only via given methods.
939 struct PaymentPath<'a> {
940 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
943 impl<'a> PaymentPath<'a> {
944 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
945 fn get_value_msat(&self) -> u64 {
946 self.hops.last().unwrap().0.fee_msat
949 fn get_path_penalty_msat(&self) -> u64 {
950 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
953 fn get_total_fee_paid_msat(&self) -> u64 {
954 if self.hops.len() < 1 {
958 // Can't use next_hops_fee_msat because it gets outdated.
959 for (i, (hop, _)) in self.hops.iter().enumerate() {
960 if i != self.hops.len() - 1 {
961 result += hop.fee_msat;
967 fn get_cost_msat(&self) -> u64 {
968 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
971 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
972 // to change fees may result in an inconsistency.
974 // Sometimes we call this function right after constructing a path which is inconsistent in
975 // that it the value being transferred has decreased while we were doing path finding, leading
976 // to the fees being paid not lining up with the actual limits.
978 // Note that this function is not aware of the available_liquidity limit, and thus does not
979 // support increasing the value being transferred beyond what was selected during the initial
981 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
982 let mut total_fee_paid_msat = 0 as u64;
983 for i in (0..self.hops.len()).rev() {
984 let last_hop = i == self.hops.len() - 1;
986 // For non-last-hop, this value will represent the fees paid on the current hop. It
987 // will consist of the fees for the use of the next hop, and extra fees to match
988 // htlc_minimum_msat of the current channel. Last hop is handled separately.
989 let mut cur_hop_fees_msat = 0;
991 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
994 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
995 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
996 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
997 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
998 // set it too high just to maliciously take more fees by exploiting this
999 // match htlc_minimum_msat logic.
1000 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
1001 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
1002 // Note that there is a risk that *previous hops* (those closer to us, as we go
1003 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
1005 // This might make us end up with a broken route, although this should be super-rare
1006 // in practice, both because of how healthy channels look like, and how we pick
1007 // channels in add_entry.
1008 // Also, this can't be exploited more heavily than *announce a free path and fail
1010 cur_hop_transferred_amount_msat += extra_fees_msat;
1011 total_fee_paid_msat += extra_fees_msat;
1012 cur_hop_fees_msat += extra_fees_msat;
1016 // Final hop is a special case: it usually has just value_msat (by design), but also
1017 // it still could overpay for the htlc_minimum_msat.
1018 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
1020 // Propagate updated fees for the use of the channels to one hop back, where they
1021 // will be actually paid (fee_msat). The last hop is handled above separately.
1022 cur_hop.fee_msat = cur_hop_fees_msat;
1025 // Fee for the use of the current hop which will be deducted on the previous hop.
1026 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
1027 // this channel is free for us.
1029 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
1030 cur_hop.hop_use_fee_msat = new_fee;
1031 total_fee_paid_msat += new_fee;
1033 // It should not be possible because this function is called only to reduce the
1034 // value. In that case, compute_fee was already called with the same fees for
1035 // larger amount and there was no overflow.
1044 /// Calculate the fees required to route the given amount over a channel with the given fees.
1045 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
1046 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1047 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
1051 /// Calculate the fees required to route the given amount over a channel with the given fees,
1052 /// saturating to [`u64::max_value`].
1053 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
1054 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
1055 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
1056 .saturating_add(channel_fees.base_msat as u64)
1059 /// The default `features` we assume for a node in a route, when no `features` are known about that
1062 /// Default features are:
1063 /// * variable_length_onion_optional
1064 fn default_node_features() -> NodeFeatures {
1065 let mut features = NodeFeatures::empty();
1066 features.set_variable_length_onion_optional();
1070 /// Finds a route from us (payer) to the given target node (payee).
1072 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
1073 /// Without this, MPP will only be used if the payee's features are available in the network graph.
1075 /// Private routing paths between a public node and the target may be included in `params.payee`.
1077 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
1078 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
1079 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
1081 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1082 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1083 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1087 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
1088 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
1093 /// Panics if first_hops contains channels without short_channel_ids;
1094 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1096 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1097 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1098 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1099 pub fn find_route<L: Deref, GL: Deref, S: Score>(
1100 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1101 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1102 scorer: &S, random_seed_bytes: &[u8; 32]
1103 ) -> Result<Route, LightningError>
1104 where L::Target: Logger, GL::Target: Logger {
1105 let graph_lock = network_graph.read_only();
1106 let final_cltv_expiry_delta = route_params.payment_params.final_cltv_expiry_delta;
1107 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
1108 route_params.final_value_msat, final_cltv_expiry_delta, logger, scorer,
1109 random_seed_bytes)?;
1110 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1114 pub(crate) fn get_route<L: Deref, S: Score>(
1115 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
1116 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
1117 logger: L, scorer: &S, _random_seed_bytes: &[u8; 32]
1118 ) -> Result<Route, LightningError>
1119 where L::Target: Logger {
1120 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
1121 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1123 if payee_node_id == our_node_id {
1124 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1127 if final_value_msat > MAX_VALUE_MSAT {
1128 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1131 if final_value_msat == 0 {
1132 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1135 match &payment_params.route_hints {
1136 Hints::Clear(hints) => {
1137 for route in hints.iter() {
1138 for hop in &route.0 {
1139 if hop.src_node_id == payment_params.payee_pubkey {
1140 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1145 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1148 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1149 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});
1152 // TODO: Remove the explicit final_cltv_expiry_delta parameter
1153 debug_assert_eq!(final_cltv_expiry_delta, payment_params.final_cltv_expiry_delta);
1155 // The general routing idea is the following:
1156 // 1. Fill first/last hops communicated by the caller.
1157 // 2. Attempt to construct a path from payer to payee for transferring
1158 // any ~sufficient (described later) value.
1159 // If succeed, remember which channels were used and how much liquidity they have available,
1160 // so that future paths don't rely on the same liquidity.
1161 // 3. Proceed to the next step if:
1162 // - we hit the recommended target value;
1163 // - OR if we could not construct a new path. Any next attempt will fail too.
1164 // Otherwise, repeat step 2.
1165 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1166 // (not recommended value).
1167 // 5. If yes, proceed. If not, fail routing.
1168 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1169 // transferred up to the transfer target value.
1170 // 7. Reduce the value of the last path until we are sending only the target value.
1171 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1172 // them so that we're not sending two HTLCs along the same path.
1174 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1175 // distance from the payee
1177 // We are not a faithful Dijkstra's implementation because we can change values which impact
1178 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1179 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1180 // the value we are currently attempting to send over a path, we simply reduce the value being
1181 // sent along the path for any hops after that channel. This may imply that later fees (which
1182 // we've already tabulated) are lower because a smaller value is passing through the channels
1183 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1184 // channels which were selected earlier (and which may still be used for other paths without a
1185 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1188 // One potentially problematic case for this algorithm would be if there are many
1189 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1190 // graph walking), we may never find a path which is not liquidity-limited and has lower
1191 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1192 // Because we only consider paths with at least 5% of the total value being sent, the damage
1193 // from such a case should be limited, however this could be further reduced in the future by
1194 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1195 // limits for the purposes of fee calculation.
1197 // Alternatively, we could store more detailed path information in the heap (targets, below)
1198 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1199 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1200 // and practically (as we would need to store dynamically-allocated path information in heap
1201 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
1202 // results of such an algorithm would likely be biased towards lower-value paths.
1204 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
1205 // outside of our current search value, running a path search more times to gather candidate
1206 // paths at different values. While this may be acceptable, further path searches may increase
1207 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
1208 // graph for candidate paths, calculating the maximum value which can realistically be sent at
1209 // the same time, remaining generic across different payment values.
1211 let network_channels = network_graph.channels();
1212 let network_nodes = network_graph.nodes();
1214 if payment_params.max_path_count == 0 {
1215 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
1218 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
1219 // it. If the payee supports it they're supposed to include it in the invoice, so that should
1221 let allow_mpp = if payment_params.max_path_count == 1 {
1223 } else if let Some(features) = &payment_params.features {
1224 features.supports_basic_mpp()
1225 } else if let Some(node) = network_nodes.get(&payee_node_id) {
1226 if let Some(node_info) = node.announcement_info.as_ref() {
1227 node_info.features.supports_basic_mpp()
1231 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
1232 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
1233 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
1236 // Prepare the data we'll use for payee-to-payer search by
1237 // inserting first hops suggested by the caller as targets.
1238 // Our search will then attempt to reach them while traversing from the payee node.
1239 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
1240 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
1241 if let Some(hops) = first_hops {
1243 if chan.get_outbound_payment_scid().is_none() {
1244 panic!("first_hops should be filled in with usable channels, not pending ones");
1246 if chan.counterparty.node_id == *our_node_pubkey {
1247 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
1250 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
1251 .or_insert(Vec::new())
1254 if first_hop_targets.is_empty() {
1255 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
1259 // The main heap containing all candidate next-hops sorted by their score (max(fee,
1260 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
1261 // adding duplicate entries when we find a better path to a given node.
1262 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
1264 // Map from node_id to information about the best current path to that node, including feerate
1266 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
1268 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
1269 // indicating that we may wish to try again with a higher value, potentially paying to meet an
1270 // htlc_minimum with extra fees while still finding a cheaper path.
1271 let mut hit_minimum_limit;
1273 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
1274 // We start with a path_value of the exact amount we want, and if that generates a route we may
1275 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
1276 // amount we want in total across paths, selecting the best subset at the end.
1277 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
1278 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
1279 let mut path_value_msat = final_value_msat;
1281 // Routing Fragmentation Mitigation heuristic:
1283 // Routing fragmentation across many payment paths increases the overall routing
1284 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
1285 // Taking too many smaller paths also increases the chance of payment failure.
1286 // Thus to avoid this effect, we require from our collected links to provide
1287 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
1288 // This requirement is currently set to be 1/max_path_count of the payment
1289 // value to ensure we only ever return routes that do not violate this limit.
1290 let minimal_value_contribution_msat: u64 = if allow_mpp {
1291 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
1296 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
1297 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
1298 // drop the requirement by setting this to 0.
1299 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
1301 // Keep track of how much liquidity has been used in selected channels. Used to determine
1302 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
1303 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
1304 // liquidity used in one direction will not offset any used in the opposite direction.
1305 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
1306 HashMap::with_capacity(network_nodes.len());
1308 // Keeping track of how much value we already collected across other paths. Helps to decide
1309 // when we want to stop looking for new paths.
1310 let mut already_collected_value_msat = 0;
1312 for (_, channels) in first_hop_targets.iter_mut() {
1313 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1314 // most like to use.
1316 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1317 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1320 // Second, because simply always sorting in descending order would always use our largest
1321 // available outbound capacity, needlessly fragmenting our available channel capacities,
1322 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1323 // which have enough, but not too much, capacity for the payment.
1324 channels.sort_unstable_by(|chan_a, chan_b| {
1325 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
1326 // Sort in descending order
1327 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
1329 // Sort in ascending order
1330 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
1335 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
1337 macro_rules! add_entry {
1338 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
1339 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
1340 // since that value has to be transferred over this channel.
1341 // Returns whether this channel caused an update to `targets`.
1342 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
1343 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
1344 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
1345 // We "return" whether we updated the path at the end, via this:
1346 let mut did_add_update_path_to_src_node = false;
1347 // Channels to self should not be used. This is more of belt-and-suspenders, because in
1348 // practice these cases should be caught earlier:
1349 // - for regular channels at channel announcement (TODO)
1350 // - for first and last hops early in get_route
1351 if $src_node_id != $dest_node_id {
1352 let short_channel_id = $candidate.short_channel_id();
1353 let effective_capacity = $candidate.effective_capacity();
1354 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
1356 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
1357 // It may be misleading because we might later choose to reduce the value transferred
1358 // over these channels, and the channel which was insufficient might become sufficient.
1359 // Worst case: we drop a good channel here because it can't cover the high following
1360 // fees caused by one expensive channel, but then this channel could have been used
1361 // if the amount being transferred over this path is lower.
1362 // We do this for now, but this is a subject for removal.
1363 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
1364 let used_liquidity_msat = used_channel_liquidities
1365 .get(&(short_channel_id, $src_node_id < $dest_node_id))
1366 .map_or(0, |used_liquidity_msat| {
1367 available_value_contribution_msat = available_value_contribution_msat
1368 .saturating_sub(*used_liquidity_msat);
1369 *used_liquidity_msat
1372 // Verify the liquidity offered by this channel complies to the minimal contribution.
1373 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
1374 // Do not consider candidate hops that would exceed the maximum path length.
1375 let path_length_to_node = $next_hops_path_length + 1;
1376 let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
1378 // Do not consider candidates that exceed the maximum total cltv expiry limit.
1379 // In order to already account for some of the privacy enhancing random CLTV
1380 // expiry delta offset we add on top later, we subtract a rough estimate
1381 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
1382 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
1383 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
1384 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
1385 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
1386 .saturating_add($candidate.cltv_expiry_delta());
1387 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
1389 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
1390 // Includes paying fees for the use of the following channels.
1391 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
1392 Some(result) => result,
1393 // Can't overflow due to how the values were computed right above.
1394 None => unreachable!(),
1396 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1397 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
1398 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
1400 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1401 let may_overpay_to_meet_path_minimum_msat =
1402 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
1403 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
1404 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
1405 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
1407 let payment_failed_on_this_channel =
1408 payment_params.previously_failed_channels.contains(&short_channel_id);
1410 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
1411 // bother considering this channel. If retrying with recommended_value_msat may
1412 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
1413 // around again with a higher amount.
1414 if !contributes_sufficient_value || exceeds_max_path_length ||
1415 exceeds_cltv_delta_limit || payment_failed_on_this_channel {
1416 // Path isn't useful, ignore it and move on.
1417 } else if may_overpay_to_meet_path_minimum_msat {
1418 hit_minimum_limit = true;
1419 } else if over_path_minimum_msat {
1420 // Note that low contribution here (limited by available_liquidity_msat)
1421 // might violate htlc_minimum_msat on the hops which are next along the
1422 // payment path (upstream to the payee). To avoid that, we recompute
1423 // path fees knowing the final path contribution after constructing it.
1424 let path_htlc_minimum_msat = cmp::max(
1425 compute_fees_saturating($next_hops_path_htlc_minimum_msat, $candidate.fees())
1426 .saturating_add($next_hops_path_htlc_minimum_msat),
1427 $candidate.htlc_minimum_msat());
1428 let hm_entry = dist.entry($src_node_id);
1429 let old_entry = hm_entry.or_insert_with(|| {
1430 // If there was previously no known way to access the source node
1431 // (recall it goes payee-to-payer) of short_channel_id, first add a
1432 // semi-dummy record just to compute the fees to reach the source node.
1433 // This will affect our decision on selecting short_channel_id
1434 // as a way to reach the $dest_node_id.
1436 node_id: $dest_node_id.clone(),
1437 candidate: $candidate.clone(),
1439 next_hops_fee_msat: u64::max_value(),
1440 hop_use_fee_msat: u64::max_value(),
1441 total_fee_msat: u64::max_value(),
1442 path_htlc_minimum_msat,
1443 path_penalty_msat: u64::max_value(),
1444 was_processed: false,
1445 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1446 value_contribution_msat,
1450 #[allow(unused_mut)] // We only use the mut in cfg(test)
1451 let mut should_process = !old_entry.was_processed;
1452 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1454 // In test/fuzzing builds, we do extra checks to make sure the skipping
1455 // of already-seen nodes only happens in cases we expect (see below).
1456 if !should_process { should_process = true; }
1460 let mut hop_use_fee_msat = 0;
1461 let mut total_fee_msat: u64 = $next_hops_fee_msat;
1463 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1464 // will have the same effective-fee
1465 if $src_node_id != our_node_id {
1466 // Note that `u64::max_value` means we'll always fail the
1467 // `old_entry.total_fee_msat > total_fee_msat` check below
1468 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
1469 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
1472 let channel_usage = ChannelUsage {
1473 amount_msat: amount_to_transfer_over_msat,
1474 inflight_htlc_msat: used_liquidity_msat,
1477 let channel_penalty_msat = scorer.channel_penalty_msat(
1478 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage
1480 let path_penalty_msat = $next_hops_path_penalty_msat
1481 .saturating_add(channel_penalty_msat);
1482 let new_graph_node = RouteGraphNode {
1483 node_id: $src_node_id,
1484 lowest_fee_to_node: total_fee_msat,
1485 total_cltv_delta: hop_total_cltv_delta,
1486 value_contribution_msat,
1487 path_htlc_minimum_msat,
1489 path_length_to_node,
1492 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1493 // if this way is cheaper than the already known
1494 // (considering the cost to "reach" this channel from the route destination,
1495 // the cost of using this channel,
1496 // and the cost of routing to the source node of this channel).
1497 // Also, consider that htlc_minimum_msat_difference, because we might end up
1498 // paying it. Consider the following exploit:
1499 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1500 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1501 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1502 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1504 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1505 // but it may require additional tracking - we don't want to double-count
1506 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1507 // can't use something that may decrease on future hops.
1508 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1509 .saturating_add(old_entry.path_penalty_msat);
1510 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1511 .saturating_add(path_penalty_msat);
1513 if !old_entry.was_processed && new_cost < old_cost {
1514 targets.push(new_graph_node);
1515 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1516 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1517 old_entry.total_fee_msat = total_fee_msat;
1518 old_entry.node_id = $dest_node_id.clone();
1519 old_entry.candidate = $candidate.clone();
1520 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1521 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1522 old_entry.path_penalty_msat = path_penalty_msat;
1523 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1525 old_entry.value_contribution_msat = value_contribution_msat;
1527 did_add_update_path_to_src_node = true;
1528 } else if old_entry.was_processed && new_cost < old_cost {
1529 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1531 // If we're skipping processing a node which was previously
1532 // processed even though we found another path to it with a
1533 // cheaper fee, check that it was because the second path we
1534 // found (which we are processing now) has a lower value
1535 // contribution due to an HTLC minimum limit.
1537 // e.g. take a graph with two paths from node 1 to node 2, one
1538 // through channel A, and one through channel B. Channel A and
1539 // B are both in the to-process heap, with their scores set by
1540 // a higher htlc_minimum than fee.
1541 // Channel A is processed first, and the channels onwards from
1542 // node 1 are added to the to-process heap. Thereafter, we pop
1543 // Channel B off of the heap, note that it has a much more
1544 // restrictive htlc_maximum_msat, and recalculate the fees for
1545 // all of node 1's channels using the new, reduced, amount.
1547 // This would be bogus - we'd be selecting a higher-fee path
1548 // with a lower htlc_maximum_msat instead of the one we'd
1549 // already decided to use.
1550 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1552 value_contribution_msat + path_penalty_msat <
1553 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1561 did_add_update_path_to_src_node
1565 let default_node_features = default_node_features();
1567 // Find ways (channels with destination) to reach a given node and store them
1568 // in the corresponding data structures (routing graph etc).
1569 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1570 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1571 // This data can later be helpful to optimize routing (pay lower fees).
1572 macro_rules! add_entries_to_cheapest_to_target_node {
1573 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1574 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1575 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1576 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1577 let was_processed = elem.was_processed;
1578 elem.was_processed = true;
1581 // Entries are added to dist in add_entry!() when there is a channel from a node.
1582 // Because there are no channels from payee, it will not have a dist entry at this point.
1583 // If we're processing any other node, it is always be the result of a channel from it.
1584 assert_eq!($node_id, payee_node_id);
1589 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1590 for details in first_channels {
1591 let candidate = CandidateRouteHop::FirstHop { details };
1592 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1593 $next_hops_value_contribution,
1594 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1595 $next_hops_cltv_delta, $next_hops_path_length);
1599 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1602 &default_node_features
1605 if !features.requires_unknown_bits() {
1606 for chan_id in $node.channels.iter() {
1607 let chan = network_channels.get(chan_id).unwrap();
1608 if !chan.features.requires_unknown_bits() {
1609 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
1610 if first_hops.is_none() || *source != our_node_id {
1611 if directed_channel.direction().enabled {
1612 let candidate = CandidateRouteHop::PublicHop {
1613 info: directed_channel,
1614 short_channel_id: *chan_id,
1616 add_entry!(candidate, *source, $node_id,
1617 $fee_to_target_msat,
1618 $next_hops_value_contribution,
1619 $next_hops_path_htlc_minimum_msat,
1620 $next_hops_path_penalty_msat,
1621 $next_hops_cltv_delta, $next_hops_path_length);
1632 let mut payment_paths = Vec::<PaymentPath>::new();
1634 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1635 'paths_collection: loop {
1636 // For every new path, start from scratch, except for used_channel_liquidities, which
1637 // helps to avoid reusing previously selected paths in future iterations.
1640 hit_minimum_limit = false;
1642 // If first hop is a private channel and the only way to reach the payee, this is the only
1643 // place where it could be added.
1644 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1645 for details in first_channels {
1646 let candidate = CandidateRouteHop::FirstHop { details };
1647 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat,
1649 log_trace!(logger, "{} direct route to payee via SCID {}",
1650 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1654 // Add the payee as a target, so that the payee-to-payer
1655 // search algorithm knows what to start with.
1656 match network_nodes.get(&payee_node_id) {
1657 // The payee is not in our network graph, so nothing to add here.
1658 // There is still a chance of reaching them via last_hops though,
1659 // so don't yet fail the payment here.
1660 // If not, targets.pop() will not even let us enter the loop in step 2.
1663 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0, 0);
1668 // If a caller provided us with last hops, add them to routing targets. Since this happens
1669 // earlier than general path finding, they will be somewhat prioritized, although currently
1670 // it matters only if the fees are exactly the same.
1671 let route_hints = match &payment_params.route_hints {
1672 Hints::Clear(hints) => hints,
1673 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1675 for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
1676 let first_hop_in_route = &(route.0)[0];
1677 let have_hop_src_in_graph =
1678 // Only add the hops in this route to our candidate set if either
1679 // we have a direct channel to the first hop or the first hop is
1680 // in the regular network graph.
1681 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1682 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1683 if have_hop_src_in_graph {
1684 // We start building the path from reverse, i.e., from payee
1685 // to the first RouteHintHop in the path.
1686 let hop_iter = route.0.iter().rev();
1687 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1688 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1689 let mut hop_used = true;
1690 let mut aggregate_next_hops_fee_msat: u64 = 0;
1691 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1692 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1693 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1694 let mut aggregate_next_hops_path_length: u8 = 0;
1696 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1697 let source = NodeId::from_pubkey(&hop.src_node_id);
1698 let target = NodeId::from_pubkey(&prev_hop_id);
1699 let candidate = network_channels
1700 .get(&hop.short_channel_id)
1701 .and_then(|channel| channel.as_directed_to(&target))
1702 .map(|(info, _)| CandidateRouteHop::PublicHop {
1704 short_channel_id: hop.short_channel_id,
1706 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1708 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
1709 path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
1710 aggregate_next_hops_path_penalty_msat,
1711 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
1712 // If this hop was not used then there is no use checking the preceding
1713 // hops in the RouteHint. We can break by just searching for a direct
1714 // channel between last checked hop and first_hop_targets.
1718 let used_liquidity_msat = used_channel_liquidities
1719 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1720 let channel_usage = ChannelUsage {
1721 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1722 inflight_htlc_msat: used_liquidity_msat,
1723 effective_capacity: candidate.effective_capacity(),
1725 let channel_penalty_msat = scorer.channel_penalty_msat(
1726 hop.short_channel_id, &source, &target, channel_usage
1728 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1729 .saturating_add(channel_penalty_msat);
1731 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1732 .saturating_add(hop.cltv_expiry_delta as u32);
1734 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1737 // Searching for a direct channel between last checked hop and first_hop_targets
1738 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1739 for details in first_channels {
1740 let candidate = CandidateRouteHop::FirstHop { details };
1741 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1742 aggregate_next_hops_fee_msat, path_value_msat,
1743 aggregate_next_hops_path_htlc_minimum_msat,
1744 aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
1745 aggregate_next_hops_path_length);
1753 // In the next values of the iterator, the aggregate fees already reflects
1754 // the sum of value sent from payer (final_value_msat) and routing fees
1755 // for the last node in the RouteHint. We need to just add the fees to
1756 // route through the current node so that the preceding node (next iteration)
1758 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1759 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1760 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1762 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1763 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1764 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1765 .checked_add(hop_htlc_minimum_msat_inc);
1766 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1768 if idx == route.0.len() - 1 {
1769 // The last hop in this iterator is the first hop in
1770 // overall RouteHint.
1771 // If this hop connects to a node with which we have a direct channel,
1772 // ignore the network graph and, if the last hop was added, add our
1773 // direct channel to the candidate set.
1775 // Note that we *must* check if the last hop was added as `add_entry`
1776 // always assumes that the third argument is a node to which we have a
1778 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1779 for details in first_channels {
1780 let candidate = CandidateRouteHop::FirstHop { details };
1781 add_entry!(candidate, our_node_id,
1782 NodeId::from_pubkey(&hop.src_node_id),
1783 aggregate_next_hops_fee_msat, path_value_msat,
1784 aggregate_next_hops_path_htlc_minimum_msat,
1785 aggregate_next_hops_path_penalty_msat,
1786 aggregate_next_hops_cltv_delta,
1787 aggregate_next_hops_path_length);
1795 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1797 // At this point, targets are filled with the data from first and
1798 // last hops communicated by the caller, and the payment receiver.
1799 let mut found_new_path = false;
1802 // If this loop terminates due the exhaustion of targets, two situations are possible:
1803 // - not enough outgoing liquidity:
1804 // 0 < already_collected_value_msat < final_value_msat
1805 // - enough outgoing liquidity:
1806 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1807 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1808 // paths_collection will be stopped because found_new_path==false.
1809 // This is not necessarily a routing failure.
1810 '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() {
1812 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1813 // traversing the graph and arrange the path out of what we found.
1814 if node_id == our_node_id {
1815 let mut new_entry = dist.remove(&our_node_id).unwrap();
1816 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1819 let mut features_set = false;
1820 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1821 for details in first_channels {
1822 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1823 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1824 features_set = true;
1830 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1831 if let Some(node_info) = node.announcement_info.as_ref() {
1832 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1834 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1837 // We can fill in features for everything except hops which were
1838 // provided via the invoice we're paying. We could guess based on the
1839 // recipient's features but for now we simply avoid guessing at all.
1843 // Means we succesfully traversed from the payer to the payee, now
1844 // save this path for the payment route. Also, update the liquidity
1845 // remaining on the used hops, so that we take them into account
1846 // while looking for more paths.
1847 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1851 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1852 Some(payment_hop) => payment_hop,
1853 // We can't arrive at None because, if we ever add an entry to targets,
1854 // we also fill in the entry in dist (see add_entry!).
1855 None => unreachable!(),
1857 // We "propagate" the fees one hop backward (topologically) here,
1858 // so that fees paid for a HTLC forwarding on the current channel are
1859 // associated with the previous channel (where they will be subtracted).
1860 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1861 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1863 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1864 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1866 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1867 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1869 let mut payment_path = PaymentPath {hops: ordered_hops};
1871 // We could have possibly constructed a slightly inconsistent path: since we reduce
1872 // value being transferred along the way, we could have violated htlc_minimum_msat
1873 // on some channels we already passed (assuming dest->source direction). Here, we
1874 // recompute the fees again, so that if that's the case, we match the currently
1875 // underpaid htlc_minimum_msat with fees.
1876 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
1877 value_contribution_msat = cmp::min(value_contribution_msat, final_value_msat);
1878 payment_path.update_value_and_recompute_fees(value_contribution_msat);
1880 // Since a path allows to transfer as much value as
1881 // the smallest channel it has ("bottleneck"), we should recompute
1882 // the fees so sender HTLC don't overpay fees when traversing
1883 // larger channels than the bottleneck. This may happen because
1884 // when we were selecting those channels we were not aware how much value
1885 // this path will transfer, and the relative fee for them
1886 // might have been computed considering a larger value.
1887 // Remember that we used these channels so that we don't rely
1888 // on the same liquidity in future paths.
1889 let mut prevented_redundant_path_selection = false;
1890 let prev_hop_iter = core::iter::once(&our_node_id)
1891 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1892 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1893 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1894 let used_liquidity_msat = used_channel_liquidities
1895 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1896 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
1897 .or_insert(spent_on_hop_msat);
1898 let hop_capacity = hop.candidate.effective_capacity();
1899 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
1900 if *used_liquidity_msat == hop_max_msat {
1901 // If this path used all of this channel's available liquidity, we know
1902 // this path will not be selected again in the next loop iteration.
1903 prevented_redundant_path_selection = true;
1905 debug_assert!(*used_liquidity_msat <= hop_max_msat);
1907 if !prevented_redundant_path_selection {
1908 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1909 // we'll probably end up picking the same path again on the next iteration.
1910 // Decrease the available liquidity of a hop in the middle of the path.
1911 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1912 let exhausted = u64::max_value();
1913 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1914 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
1915 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
1918 // Track the total amount all our collected paths allow to send so that we know
1919 // when to stop looking for more paths
1920 already_collected_value_msat += value_contribution_msat;
1922 payment_paths.push(payment_path);
1923 found_new_path = true;
1924 break 'path_construction;
1927 // If we found a path back to the payee, we shouldn't try to process it again. This is
1928 // the equivalent of the `elem.was_processed` check in
1929 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1930 if node_id == payee_node_id { continue 'path_construction; }
1932 // Otherwise, since the current target node is not us,
1933 // keep "unrolling" the payment graph from payee to payer by
1934 // finding a way to reach the current target from the payer side.
1935 match network_nodes.get(&node_id) {
1938 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
1939 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
1940 total_cltv_delta, path_length_to_node);
1946 if !found_new_path && channel_saturation_pow_half != 0 {
1947 channel_saturation_pow_half = 0;
1948 continue 'paths_collection;
1950 // If we don't support MPP, no use trying to gather more value ever.
1951 break 'paths_collection;
1955 // Stop either when the recommended value is reached or if no new path was found in this
1957 // In the latter case, making another path finding attempt won't help,
1958 // because we deterministically terminated the search due to low liquidity.
1959 if !found_new_path && channel_saturation_pow_half != 0 {
1960 channel_saturation_pow_half = 0;
1961 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1962 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1963 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1964 break 'paths_collection;
1965 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1966 // Further, if this was our first walk of the graph, and we weren't limited by an
1967 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1968 // limited by an htlc_minimum_msat value, find another path with a higher value,
1969 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1970 // still keeping a lower total fee than this path.
1971 if !hit_minimum_limit {
1972 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1973 break 'paths_collection;
1975 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1976 path_value_msat = recommended_value_msat;
1981 if payment_paths.len() == 0 {
1982 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1985 if already_collected_value_msat < final_value_msat {
1986 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1990 let mut selected_route = payment_paths;
1992 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
1993 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
1995 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
1996 // the value they contribute towards the payment amount.
1997 // We sort in descending order as we will remove from the front in `retain`, next.
1998 selected_route.sort_unstable_by(|a, b|
1999 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
2000 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
2003 // We should make sure that at least 1 path left.
2004 let mut paths_left = selected_route.len();
2005 selected_route.retain(|path| {
2006 if paths_left == 1 {
2009 let path_value_msat = path.get_value_msat();
2010 if path_value_msat <= overpaid_value_msat {
2011 overpaid_value_msat -= path_value_msat;
2017 debug_assert!(selected_route.len() > 0);
2019 if overpaid_value_msat != 0 {
2021 // Now, subtract the remaining overpaid value from the most-expensive path.
2022 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
2023 // so that the sender pays less fees overall. And also htlc_minimum_msat.
2024 selected_route.sort_unstable_by(|a, b| {
2025 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2026 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
2027 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
2029 let expensive_payment_path = selected_route.first_mut().unwrap();
2031 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
2032 // can't go negative.
2033 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
2034 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
2038 // Sort by the path itself and combine redundant paths.
2039 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
2040 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
2042 selected_route.sort_unstable_by_key(|path| {
2043 let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
2044 debug_assert!(path.hops.len() <= key.len());
2045 for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
2050 for idx in 0..(selected_route.len() - 1) {
2051 if idx + 1 >= selected_route.len() { break; }
2052 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
2053 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
2054 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
2055 selected_route[idx].update_value_and_recompute_fees(new_value);
2056 selected_route.remove(idx + 1);
2060 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
2061 for payment_path in selected_route {
2062 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
2064 pubkey: PublicKey::from_slice(payment_hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &payment_hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
2065 node_features: node_features.clone(),
2066 short_channel_id: payment_hop.candidate.short_channel_id(),
2067 channel_features: payment_hop.candidate.features(),
2068 fee_msat: payment_hop.fee_msat,
2069 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
2071 }).collect::<Vec<_>>();
2072 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
2073 // applicable for the previous hop.
2074 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
2075 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
2077 selected_paths.push(path);
2079 // Make sure we would never create a route with more paths than we allow.
2080 debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
2082 if let Some(features) = &payment_params.features {
2083 for path in selected_paths.iter_mut() {
2084 if let Ok(route_hop) = path.last_mut().unwrap() {
2085 route_hop.node_features = features.to_context();
2090 let mut paths: Vec<Path> = Vec::new();
2091 for results_vec in selected_paths {
2092 let mut hops = Vec::with_capacity(results_vec.len());
2093 for res in results_vec { hops.push(res?); }
2094 paths.push(Path { hops, blinded_tail: None });
2098 payment_params: Some(payment_params.clone()),
2100 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
2104 // When an adversarial intermediary node observes a payment, it may be able to infer its
2105 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
2106 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
2107 // payment path by adding a randomized 'shadow route' offset to the final hop.
2108 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
2109 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
2111 let network_channels = network_graph.channels();
2112 let network_nodes = network_graph.nodes();
2114 for path in route.paths.iter_mut() {
2115 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
2117 // Remember the last three nodes of the random walk and avoid looping back on them.
2118 // Init with the last three nodes from the actual path, if possible.
2119 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.hops.last().unwrap().pubkey),
2120 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(2)).unwrap().pubkey),
2121 NodeId::from_pubkey(&path.hops.get(path.hops.len().saturating_sub(3)).unwrap().pubkey)];
2123 // Choose the last publicly known node as the starting point for the random walk.
2124 let mut cur_hop: Option<NodeId> = None;
2125 let mut path_nonce = [0u8; 12];
2126 if let Some(starting_hop) = path.hops.iter().rev()
2127 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
2128 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
2129 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
2132 // Init PRNG with the path-dependant nonce, which is static for private paths.
2133 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
2134 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
2136 // Pick a random path length in [1 .. 3]
2137 prng.process_in_place(&mut random_path_bytes);
2138 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
2140 for random_hop in 0..random_walk_length {
2141 // If we don't find a suitable offset in the public network graph, we default to
2142 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2143 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
2145 if let Some(cur_node_id) = cur_hop {
2146 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
2147 // Randomly choose the next unvisited hop.
2148 prng.process_in_place(&mut random_path_bytes);
2149 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
2150 .checked_rem(cur_node.channels.len())
2151 .and_then(|index| cur_node.channels.get(index))
2152 .and_then(|id| network_channels.get(id)) {
2153 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
2154 if !nodes_to_avoid.iter().any(|x| x == next_id) {
2155 nodes_to_avoid[random_hop] = *next_id;
2156 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
2157 cur_hop = Some(*next_id);
2164 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
2165 .checked_add(random_hop_offset)
2166 .unwrap_or(shadow_ctlv_expiry_delta_offset);
2169 // Limit the total offset to reduce the worst-case locked liquidity timevalue
2170 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
2171 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
2173 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
2174 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2175 let path_total_cltv_expiry_delta: u32 = path.hops.iter().map(|h| h.cltv_expiry_delta).sum();
2176 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
2177 max_path_offset = cmp::max(
2178 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
2179 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
2180 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
2182 // Add 'shadow' CLTV offset to the final hop
2183 if let Some(last_hop) = path.hops.last_mut() {
2184 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
2185 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
2190 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
2191 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
2193 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
2194 pub fn build_route_from_hops<L: Deref, GL: Deref>(
2195 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
2196 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
2197 ) -> Result<Route, LightningError>
2198 where L::Target: Logger, GL::Target: Logger {
2199 let graph_lock = network_graph.read_only();
2200 let mut route = build_route_from_hops_internal(
2201 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
2202 route_params.final_value_msat, route_params.payment_params.final_cltv_expiry_delta,
2203 logger, random_seed_bytes)?;
2204 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
2208 fn build_route_from_hops_internal<L: Deref>(
2209 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
2210 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
2211 logger: L, random_seed_bytes: &[u8; 32]
2212 ) -> Result<Route, LightningError> where L::Target: Logger {
2215 our_node_id: NodeId,
2216 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
2219 impl Score for HopScorer {
2220 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
2221 _usage: ChannelUsage) -> u64
2223 let mut cur_id = self.our_node_id;
2224 for i in 0..self.hop_ids.len() {
2225 if let Some(next_id) = self.hop_ids[i] {
2226 if cur_id == *source && next_id == *target {
2237 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2239 fn payment_path_successful(&mut self, _path: &Path) {}
2241 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
2243 fn probe_successful(&mut self, _path: &Path) {}
2246 impl<'a> Writeable for HopScorer {
2248 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
2253 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
2254 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
2257 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
2258 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
2259 for i in 0..hops.len() {
2260 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
2263 let scorer = HopScorer { our_node_id, hop_ids };
2265 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
2266 final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
2271 use crate::blinded_path::{BlindedHop, BlindedPath};
2272 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
2273 use crate::routing::utxo::UtxoResult;
2274 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
2275 BlindedTail, InFlightHtlcs, Path, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
2276 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
2277 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringParameters};
2278 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
2279 use crate::chain::transaction::OutPoint;
2280 use crate::chain::keysinterface::EntropySource;
2281 use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
2282 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
2283 use crate::ln::channelmanager;
2284 use crate::util::config::UserConfig;
2285 use crate::util::test_utils as ln_test_utils;
2286 use crate::util::chacha20::ChaCha20;
2287 use crate::util::ser::{Readable, Writeable};
2289 use crate::util::ser::Writer;
2291 use bitcoin::hashes::Hash;
2292 use bitcoin::network::constants::Network;
2293 use bitcoin::blockdata::constants::genesis_block;
2294 use bitcoin::blockdata::script::Builder;
2295 use bitcoin::blockdata::opcodes;
2296 use bitcoin::blockdata::transaction::TxOut;
2300 use bitcoin::secp256k1::{PublicKey,SecretKey};
2301 use bitcoin::secp256k1::Secp256k1;
2303 use crate::io::Cursor;
2304 use crate::prelude::*;
2305 use crate::sync::Arc;
2307 use core::convert::TryInto;
2309 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
2310 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
2311 channelmanager::ChannelDetails {
2312 channel_id: [0; 32],
2313 counterparty: channelmanager::ChannelCounterparty {
2316 unspendable_punishment_reserve: 0,
2317 forwarding_info: None,
2318 outbound_htlc_minimum_msat: None,
2319 outbound_htlc_maximum_msat: None,
2321 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2324 outbound_scid_alias: None,
2325 inbound_scid_alias: None,
2326 channel_value_satoshis: 0,
2329 outbound_capacity_msat,
2330 next_outbound_htlc_limit_msat: outbound_capacity_msat,
2331 inbound_capacity_msat: 42,
2332 unspendable_punishment_reserve: None,
2333 confirmations_required: None,
2334 confirmations: None,
2335 force_close_spend_delay: None,
2336 is_outbound: true, is_channel_ready: true,
2337 is_usable: true, is_public: true,
2338 inbound_htlc_minimum_msat: None,
2339 inbound_htlc_maximum_msat: None,
2341 feerate_sat_per_1000_weight: None
2346 fn simple_route_test() {
2347 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2348 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2349 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2350 let scorer = ln_test_utils::TestScorer::new();
2351 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2352 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2354 // Simple route to 2 via 1
2356 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 0, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2357 assert_eq!(err, "Cannot send a payment of 0 msat");
2358 } else { panic!(); }
2360 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2361 assert_eq!(route.paths[0].hops.len(), 2);
2363 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2364 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2365 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
2366 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2367 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2368 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2370 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2371 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2372 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2373 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2374 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2375 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2379 fn invalid_first_hop_test() {
2380 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2381 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2382 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2383 let scorer = ln_test_utils::TestScorer::new();
2384 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2385 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2387 // Simple route to 2 via 1
2389 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2391 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2392 get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2393 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2394 } else { panic!(); }
2396 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2397 assert_eq!(route.paths[0].hops.len(), 2);
2401 fn htlc_minimum_test() {
2402 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2403 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2404 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2405 let scorer = ln_test_utils::TestScorer::new();
2406 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2407 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2409 // Simple route to 2 via 1
2411 // Disable other paths
2412 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2413 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2414 short_channel_id: 12,
2416 flags: 2, // to disable
2417 cltv_expiry_delta: 0,
2418 htlc_minimum_msat: 0,
2419 htlc_maximum_msat: MAX_VALUE_MSAT,
2421 fee_proportional_millionths: 0,
2422 excess_data: Vec::new()
2424 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2425 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2426 short_channel_id: 3,
2428 flags: 2, // to disable
2429 cltv_expiry_delta: 0,
2430 htlc_minimum_msat: 0,
2431 htlc_maximum_msat: MAX_VALUE_MSAT,
2433 fee_proportional_millionths: 0,
2434 excess_data: Vec::new()
2436 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2437 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2438 short_channel_id: 13,
2440 flags: 2, // to disable
2441 cltv_expiry_delta: 0,
2442 htlc_minimum_msat: 0,
2443 htlc_maximum_msat: MAX_VALUE_MSAT,
2445 fee_proportional_millionths: 0,
2446 excess_data: Vec::new()
2448 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2449 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2450 short_channel_id: 6,
2452 flags: 2, // to disable
2453 cltv_expiry_delta: 0,
2454 htlc_minimum_msat: 0,
2455 htlc_maximum_msat: MAX_VALUE_MSAT,
2457 fee_proportional_millionths: 0,
2458 excess_data: Vec::new()
2460 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2461 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2462 short_channel_id: 7,
2464 flags: 2, // to disable
2465 cltv_expiry_delta: 0,
2466 htlc_minimum_msat: 0,
2467 htlc_maximum_msat: MAX_VALUE_MSAT,
2469 fee_proportional_millionths: 0,
2470 excess_data: Vec::new()
2473 // Check against amount_to_transfer_over_msat.
2474 // Set minimal HTLC of 200_000_000 msat.
2475 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2477 short_channel_id: 2,
2480 cltv_expiry_delta: 0,
2481 htlc_minimum_msat: 200_000_000,
2482 htlc_maximum_msat: MAX_VALUE_MSAT,
2484 fee_proportional_millionths: 0,
2485 excess_data: Vec::new()
2488 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2490 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2491 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2492 short_channel_id: 4,
2495 cltv_expiry_delta: 0,
2496 htlc_minimum_msat: 0,
2497 htlc_maximum_msat: 199_999_999,
2499 fee_proportional_millionths: 0,
2500 excess_data: Vec::new()
2503 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2504 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2505 assert_eq!(err, "Failed to find a path to the given destination");
2506 } else { panic!(); }
2508 // Lift the restriction on the first hop.
2509 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2510 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2511 short_channel_id: 2,
2514 cltv_expiry_delta: 0,
2515 htlc_minimum_msat: 0,
2516 htlc_maximum_msat: MAX_VALUE_MSAT,
2518 fee_proportional_millionths: 0,
2519 excess_data: Vec::new()
2522 // A payment above the minimum should pass
2523 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2524 assert_eq!(route.paths[0].hops.len(), 2);
2528 fn htlc_minimum_overpay_test() {
2529 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2530 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2531 let config = UserConfig::default();
2532 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
2533 let scorer = ln_test_utils::TestScorer::new();
2534 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2535 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2537 // A route to node#2 via two paths.
2538 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2539 // Thus, they can't send 60 without overpaying.
2540 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2541 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2542 short_channel_id: 2,
2545 cltv_expiry_delta: 0,
2546 htlc_minimum_msat: 35_000,
2547 htlc_maximum_msat: 40_000,
2549 fee_proportional_millionths: 0,
2550 excess_data: Vec::new()
2552 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2553 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2554 short_channel_id: 12,
2557 cltv_expiry_delta: 0,
2558 htlc_minimum_msat: 35_000,
2559 htlc_maximum_msat: 40_000,
2561 fee_proportional_millionths: 0,
2562 excess_data: Vec::new()
2566 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2567 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2568 short_channel_id: 13,
2571 cltv_expiry_delta: 0,
2572 htlc_minimum_msat: 0,
2573 htlc_maximum_msat: MAX_VALUE_MSAT,
2575 fee_proportional_millionths: 0,
2576 excess_data: Vec::new()
2578 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2579 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2580 short_channel_id: 4,
2583 cltv_expiry_delta: 0,
2584 htlc_minimum_msat: 0,
2585 htlc_maximum_msat: MAX_VALUE_MSAT,
2587 fee_proportional_millionths: 0,
2588 excess_data: Vec::new()
2591 // Disable other paths
2592 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2593 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2594 short_channel_id: 1,
2596 flags: 2, // to disable
2597 cltv_expiry_delta: 0,
2598 htlc_minimum_msat: 0,
2599 htlc_maximum_msat: MAX_VALUE_MSAT,
2601 fee_proportional_millionths: 0,
2602 excess_data: Vec::new()
2605 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2606 // Overpay fees to hit htlc_minimum_msat.
2607 let overpaid_fees = route.paths[0].hops[0].fee_msat + route.paths[1].hops[0].fee_msat;
2608 // TODO: this could be better balanced to overpay 10k and not 15k.
2609 assert_eq!(overpaid_fees, 15_000);
2611 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2612 // while taking even more fee to match htlc_minimum_msat.
2613 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2614 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2615 short_channel_id: 12,
2618 cltv_expiry_delta: 0,
2619 htlc_minimum_msat: 65_000,
2620 htlc_maximum_msat: 80_000,
2622 fee_proportional_millionths: 0,
2623 excess_data: Vec::new()
2625 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2626 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2627 short_channel_id: 2,
2630 cltv_expiry_delta: 0,
2631 htlc_minimum_msat: 0,
2632 htlc_maximum_msat: MAX_VALUE_MSAT,
2634 fee_proportional_millionths: 0,
2635 excess_data: Vec::new()
2637 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2638 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2639 short_channel_id: 4,
2642 cltv_expiry_delta: 0,
2643 htlc_minimum_msat: 0,
2644 htlc_maximum_msat: MAX_VALUE_MSAT,
2646 fee_proportional_millionths: 100_000,
2647 excess_data: Vec::new()
2650 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2651 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2652 assert_eq!(route.paths.len(), 1);
2653 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
2654 let fees = route.paths[0].hops[0].fee_msat;
2655 assert_eq!(fees, 5_000);
2657 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2658 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2659 // the other channel.
2660 assert_eq!(route.paths.len(), 1);
2661 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2662 let fees = route.paths[0].hops[0].fee_msat;
2663 assert_eq!(fees, 5_000);
2667 fn disable_channels_test() {
2668 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2669 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2670 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2671 let scorer = ln_test_utils::TestScorer::new();
2672 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2673 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2675 // // Disable channels 4 and 12 by flags=2
2676 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2677 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2678 short_channel_id: 4,
2680 flags: 2, // to disable
2681 cltv_expiry_delta: 0,
2682 htlc_minimum_msat: 0,
2683 htlc_maximum_msat: MAX_VALUE_MSAT,
2685 fee_proportional_millionths: 0,
2686 excess_data: Vec::new()
2688 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2689 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2690 short_channel_id: 12,
2692 flags: 2, // to disable
2693 cltv_expiry_delta: 0,
2694 htlc_minimum_msat: 0,
2695 htlc_maximum_msat: MAX_VALUE_MSAT,
2697 fee_proportional_millionths: 0,
2698 excess_data: Vec::new()
2701 // If all the channels require some features we don't understand, route should fail
2702 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2703 assert_eq!(err, "Failed to find a path to the given destination");
2704 } else { panic!(); }
2706 // If we specify a channel to node7, that overrides our local channel view and that gets used
2707 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2708 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2709 assert_eq!(route.paths[0].hops.len(), 2);
2711 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2712 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2713 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2714 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2715 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2716 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2718 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2719 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2720 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2721 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2722 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2723 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2727 fn disable_node_test() {
2728 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2729 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2730 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2731 let scorer = ln_test_utils::TestScorer::new();
2732 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2733 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2735 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2736 let mut unknown_features = NodeFeatures::empty();
2737 unknown_features.set_unknown_feature_required();
2738 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2739 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2740 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2742 // If all nodes require some features we don't understand, route should fail
2743 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2744 assert_eq!(err, "Failed to find a path to the given destination");
2745 } else { panic!(); }
2747 // If we specify a channel to node7, that overrides our local channel view and that gets used
2748 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2749 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2750 assert_eq!(route.paths[0].hops.len(), 2);
2752 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2753 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2754 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2755 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2756 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2757 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2759 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2760 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2761 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2762 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2763 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2764 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2766 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2767 // naively) assume that the user checked the feature bits on the invoice, which override
2768 // the node_announcement.
2772 fn our_chans_test() {
2773 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2774 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2775 let scorer = ln_test_utils::TestScorer::new();
2776 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2777 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2779 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2780 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
2781 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2782 assert_eq!(route.paths[0].hops.len(), 3);
2784 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2785 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2786 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2787 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2788 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2789 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2791 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2792 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2793 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2794 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (3 << 4) | 2);
2795 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2796 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2798 assert_eq!(route.paths[0].hops[2].pubkey, nodes[0]);
2799 assert_eq!(route.paths[0].hops[2].short_channel_id, 3);
2800 assert_eq!(route.paths[0].hops[2].fee_msat, 100);
2801 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
2802 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(1));
2803 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(3));
2805 // If we specify a channel to node7, that overrides our local channel view and that gets used
2806 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2807 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2808 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2809 assert_eq!(route.paths[0].hops.len(), 2);
2811 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
2812 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
2813 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
2814 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
2815 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
2816 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2818 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2819 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
2820 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
2821 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
2822 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2823 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
2826 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2827 let zero_fees = RoutingFees {
2829 proportional_millionths: 0,
2831 vec![RouteHint(vec![RouteHintHop {
2832 src_node_id: nodes[3],
2833 short_channel_id: 8,
2835 cltv_expiry_delta: (8 << 4) | 1,
2836 htlc_minimum_msat: None,
2837 htlc_maximum_msat: None,
2839 ]), RouteHint(vec![RouteHintHop {
2840 src_node_id: nodes[4],
2841 short_channel_id: 9,
2844 proportional_millionths: 0,
2846 cltv_expiry_delta: (9 << 4) | 1,
2847 htlc_minimum_msat: None,
2848 htlc_maximum_msat: None,
2849 }]), RouteHint(vec![RouteHintHop {
2850 src_node_id: nodes[5],
2851 short_channel_id: 10,
2853 cltv_expiry_delta: (10 << 4) | 1,
2854 htlc_minimum_msat: None,
2855 htlc_maximum_msat: None,
2859 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2860 let zero_fees = RoutingFees {
2862 proportional_millionths: 0,
2864 vec![RouteHint(vec![RouteHintHop {
2865 src_node_id: nodes[2],
2866 short_channel_id: 5,
2869 proportional_millionths: 0,
2871 cltv_expiry_delta: (5 << 4) | 1,
2872 htlc_minimum_msat: None,
2873 htlc_maximum_msat: None,
2875 src_node_id: nodes[3],
2876 short_channel_id: 8,
2878 cltv_expiry_delta: (8 << 4) | 1,
2879 htlc_minimum_msat: None,
2880 htlc_maximum_msat: None,
2882 ]), RouteHint(vec![RouteHintHop {
2883 src_node_id: nodes[4],
2884 short_channel_id: 9,
2887 proportional_millionths: 0,
2889 cltv_expiry_delta: (9 << 4) | 1,
2890 htlc_minimum_msat: None,
2891 htlc_maximum_msat: None,
2892 }]), RouteHint(vec![RouteHintHop {
2893 src_node_id: nodes[5],
2894 short_channel_id: 10,
2896 cltv_expiry_delta: (10 << 4) | 1,
2897 htlc_minimum_msat: None,
2898 htlc_maximum_msat: None,
2903 fn partial_route_hint_test() {
2904 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2905 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2906 let scorer = ln_test_utils::TestScorer::new();
2907 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2908 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2910 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2911 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2912 // RouteHint may be partially used by the algo to build the best path.
2914 // First check that last hop can't have its source as the payee.
2915 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2916 src_node_id: nodes[6],
2917 short_channel_id: 8,
2920 proportional_millionths: 0,
2922 cltv_expiry_delta: (8 << 4) | 1,
2923 htlc_minimum_msat: None,
2924 htlc_maximum_msat: None,
2927 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2928 invalid_last_hops.push(invalid_last_hop);
2930 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops);
2931 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2932 assert_eq!(err, "Route hint cannot have the payee as the source.");
2933 } else { panic!(); }
2936 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes));
2937 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2938 assert_eq!(route.paths[0].hops.len(), 5);
2940 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
2941 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
2942 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
2943 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
2944 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
2945 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
2947 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
2948 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
2949 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
2950 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
2951 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
2952 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
2954 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
2955 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
2956 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
2957 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
2958 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
2959 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
2961 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
2962 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
2963 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
2964 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
2965 // If we have a peer in the node map, we'll use their features here since we don't have
2966 // a way of figuring out their features from the invoice:
2967 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
2968 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
2970 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
2971 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
2972 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
2973 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
2974 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2975 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2978 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2979 let zero_fees = RoutingFees {
2981 proportional_millionths: 0,
2983 vec![RouteHint(vec![RouteHintHop {
2984 src_node_id: nodes[3],
2985 short_channel_id: 8,
2987 cltv_expiry_delta: (8 << 4) | 1,
2988 htlc_minimum_msat: None,
2989 htlc_maximum_msat: None,
2990 }]), RouteHint(vec![
2992 ]), RouteHint(vec![RouteHintHop {
2993 src_node_id: nodes[5],
2994 short_channel_id: 10,
2996 cltv_expiry_delta: (10 << 4) | 1,
2997 htlc_minimum_msat: None,
2998 htlc_maximum_msat: None,
3003 fn ignores_empty_last_hops_test() {
3004 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3005 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3006 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes));
3007 let scorer = ln_test_utils::TestScorer::new();
3008 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3009 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3011 // Test handling of an empty RouteHint passed in Invoice.
3013 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3014 assert_eq!(route.paths[0].hops.len(), 5);
3016 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3017 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3018 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3019 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3020 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3021 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3023 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3024 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3025 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3026 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3027 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3028 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3030 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3031 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3032 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3033 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3034 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3035 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3037 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3038 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3039 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3040 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3041 // If we have a peer in the node map, we'll use their features here since we don't have
3042 // a way of figuring out their features from the invoice:
3043 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3044 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3046 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3047 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3048 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3049 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3050 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3051 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3054 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3056 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3057 let zero_fees = RoutingFees {
3059 proportional_millionths: 0,
3061 vec![RouteHint(vec![RouteHintHop {
3062 src_node_id: hint_hops[0],
3063 short_channel_id: 0xff00,
3066 proportional_millionths: 0,
3068 cltv_expiry_delta: (5 << 4) | 1,
3069 htlc_minimum_msat: None,
3070 htlc_maximum_msat: None,
3072 src_node_id: hint_hops[1],
3073 short_channel_id: 0xff01,
3075 cltv_expiry_delta: (8 << 4) | 1,
3076 htlc_minimum_msat: None,
3077 htlc_maximum_msat: None,
3082 fn multi_hint_last_hops_test() {
3083 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3084 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3085 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3086 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
3087 let scorer = ln_test_utils::TestScorer::new();
3088 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3089 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3090 // Test through channels 2, 3, 0xff00, 0xff01.
3091 // Test shows that multiple hop hints are considered.
3093 // Disabling channels 6 & 7 by flags=2
3094 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3095 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3096 short_channel_id: 6,
3098 flags: 2, // to disable
3099 cltv_expiry_delta: 0,
3100 htlc_minimum_msat: 0,
3101 htlc_maximum_msat: MAX_VALUE_MSAT,
3103 fee_proportional_millionths: 0,
3104 excess_data: Vec::new()
3106 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3107 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3108 short_channel_id: 7,
3110 flags: 2, // to disable
3111 cltv_expiry_delta: 0,
3112 htlc_minimum_msat: 0,
3113 htlc_maximum_msat: MAX_VALUE_MSAT,
3115 fee_proportional_millionths: 0,
3116 excess_data: Vec::new()
3119 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3120 assert_eq!(route.paths[0].hops.len(), 4);
3122 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3123 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3124 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3125 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3126 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3127 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3129 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3130 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3131 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3132 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3133 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3134 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3136 assert_eq!(route.paths[0].hops[2].pubkey, nodes[3]);
3137 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3138 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3139 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3140 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(4));
3141 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3143 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3144 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3145 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3146 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3147 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3148 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3152 fn private_multi_hint_last_hops_test() {
3153 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3154 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3156 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3157 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3159 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3160 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
3161 let scorer = ln_test_utils::TestScorer::new();
3162 // Test through channels 2, 3, 0xff00, 0xff01.
3163 // Test shows that multiple hop hints are considered.
3165 // Disabling channels 6 & 7 by flags=2
3166 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3167 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3168 short_channel_id: 6,
3170 flags: 2, // to disable
3171 cltv_expiry_delta: 0,
3172 htlc_minimum_msat: 0,
3173 htlc_maximum_msat: MAX_VALUE_MSAT,
3175 fee_proportional_millionths: 0,
3176 excess_data: Vec::new()
3178 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3179 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3180 short_channel_id: 7,
3182 flags: 2, // to disable
3183 cltv_expiry_delta: 0,
3184 htlc_minimum_msat: 0,
3185 htlc_maximum_msat: MAX_VALUE_MSAT,
3187 fee_proportional_millionths: 0,
3188 excess_data: Vec::new()
3191 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3192 assert_eq!(route.paths[0].hops.len(), 4);
3194 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3195 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3196 assert_eq!(route.paths[0].hops[0].fee_msat, 200);
3197 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, 65);
3198 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3199 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3201 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3202 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3203 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3204 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 81);
3205 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3206 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3208 assert_eq!(route.paths[0].hops[2].pubkey, non_announced_pubkey);
3209 assert_eq!(route.paths[0].hops[2].short_channel_id, last_hops[0].0[0].short_channel_id);
3210 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3211 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 129);
3212 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3213 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3215 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3216 assert_eq!(route.paths[0].hops[3].short_channel_id, last_hops[0].0[1].short_channel_id);
3217 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3218 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3219 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3220 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3223 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3224 let zero_fees = RoutingFees {
3226 proportional_millionths: 0,
3228 vec![RouteHint(vec![RouteHintHop {
3229 src_node_id: nodes[4],
3230 short_channel_id: 11,
3232 cltv_expiry_delta: (11 << 4) | 1,
3233 htlc_minimum_msat: None,
3234 htlc_maximum_msat: None,
3236 src_node_id: nodes[3],
3237 short_channel_id: 8,
3239 cltv_expiry_delta: (8 << 4) | 1,
3240 htlc_minimum_msat: None,
3241 htlc_maximum_msat: None,
3242 }]), RouteHint(vec![RouteHintHop {
3243 src_node_id: nodes[4],
3244 short_channel_id: 9,
3247 proportional_millionths: 0,
3249 cltv_expiry_delta: (9 << 4) | 1,
3250 htlc_minimum_msat: None,
3251 htlc_maximum_msat: None,
3252 }]), RouteHint(vec![RouteHintHop {
3253 src_node_id: nodes[5],
3254 short_channel_id: 10,
3256 cltv_expiry_delta: (10 << 4) | 1,
3257 htlc_minimum_msat: None,
3258 htlc_maximum_msat: None,
3263 fn last_hops_with_public_channel_test() {
3264 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3265 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3266 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes));
3267 let scorer = ln_test_utils::TestScorer::new();
3268 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3269 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3270 // This test shows that public routes can be present in the invoice
3271 // which would be handled in the same manner.
3273 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3274 assert_eq!(route.paths[0].hops.len(), 5);
3276 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3277 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3278 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
3279 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3280 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3281 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3283 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3284 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3285 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3286 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3287 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3288 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3290 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3291 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3292 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3293 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3294 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3295 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3297 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3298 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3299 assert_eq!(route.paths[0].hops[3].fee_msat, 0);
3300 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3301 // If we have a peer in the node map, we'll use their features here since we don't have
3302 // a way of figuring out their features from the invoice:
3303 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3304 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3306 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3307 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3308 assert_eq!(route.paths[0].hops[4].fee_msat, 100);
3309 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3310 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3311 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3315 fn our_chans_last_hop_connect_test() {
3316 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3317 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3318 let scorer = ln_test_utils::TestScorer::new();
3319 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3320 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3322 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3323 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3324 let mut last_hops = last_hops(&nodes);
3325 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
3326 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3327 assert_eq!(route.paths[0].hops.len(), 2);
3329 assert_eq!(route.paths[0].hops[0].pubkey, nodes[3]);
3330 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3331 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
3332 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3333 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &vec![0b11]);
3334 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3336 assert_eq!(route.paths[0].hops[1].pubkey, nodes[6]);
3337 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3338 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3339 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3340 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3341 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3343 last_hops[0].0[0].fees.base_msat = 1000;
3345 // Revert to via 6 as the fee on 8 goes up
3346 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops);
3347 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3348 assert_eq!(route.paths[0].hops.len(), 4);
3350 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3351 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3352 assert_eq!(route.paths[0].hops[0].fee_msat, 200); // fee increased as its % of value transferred across node
3353 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3354 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3355 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3357 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3358 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3359 assert_eq!(route.paths[0].hops[1].fee_msat, 100);
3360 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (7 << 4) | 1);
3361 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3362 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3364 assert_eq!(route.paths[0].hops[2].pubkey, nodes[5]);
3365 assert_eq!(route.paths[0].hops[2].short_channel_id, 7);
3366 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3367 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (10 << 4) | 1);
3368 // If we have a peer in the node map, we'll use their features here since we don't have
3369 // a way of figuring out their features from the invoice:
3370 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
3371 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(7));
3373 assert_eq!(route.paths[0].hops[3].pubkey, nodes[6]);
3374 assert_eq!(route.paths[0].hops[3].short_channel_id, 10);
3375 assert_eq!(route.paths[0].hops[3].fee_msat, 100);
3376 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, 42);
3377 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3378 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3380 // ...but still use 8 for larger payments as 6 has a variable feerate
3381 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3382 assert_eq!(route.paths[0].hops.len(), 5);
3384 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
3385 assert_eq!(route.paths[0].hops[0].short_channel_id, 2);
3386 assert_eq!(route.paths[0].hops[0].fee_msat, 3000);
3387 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (4 << 4) | 1);
3388 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(2));
3389 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(2));
3391 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
3392 assert_eq!(route.paths[0].hops[1].short_channel_id, 4);
3393 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
3394 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (6 << 4) | 1);
3395 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
3396 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(4));
3398 assert_eq!(route.paths[0].hops[2].pubkey, nodes[4]);
3399 assert_eq!(route.paths[0].hops[2].short_channel_id, 6);
3400 assert_eq!(route.paths[0].hops[2].fee_msat, 0);
3401 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, (11 << 4) | 1);
3402 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(5));
3403 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(6));
3405 assert_eq!(route.paths[0].hops[3].pubkey, nodes[3]);
3406 assert_eq!(route.paths[0].hops[3].short_channel_id, 11);
3407 assert_eq!(route.paths[0].hops[3].fee_msat, 1000);
3408 assert_eq!(route.paths[0].hops[3].cltv_expiry_delta, (8 << 4) | 1);
3409 // If we have a peer in the node map, we'll use their features here since we don't have
3410 // a way of figuring out their features from the invoice:
3411 assert_eq!(route.paths[0].hops[3].node_features.le_flags(), &id_to_feature_flags(4));
3412 assert_eq!(route.paths[0].hops[3].channel_features.le_flags(), &id_to_feature_flags(11));
3414 assert_eq!(route.paths[0].hops[4].pubkey, nodes[6]);
3415 assert_eq!(route.paths[0].hops[4].short_channel_id, 8);
3416 assert_eq!(route.paths[0].hops[4].fee_msat, 2000);
3417 assert_eq!(route.paths[0].hops[4].cltv_expiry_delta, 42);
3418 assert_eq!(route.paths[0].hops[4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3419 assert_eq!(route.paths[0].hops[4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3422 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> {
3423 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3424 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3425 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3427 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3428 let last_hops = RouteHint(vec![RouteHintHop {
3429 src_node_id: middle_node_id,
3430 short_channel_id: 8,
3433 proportional_millionths: last_hop_fee_prop,
3435 cltv_expiry_delta: (8 << 4) | 1,
3436 htlc_minimum_msat: None,
3437 htlc_maximum_msat: last_hop_htlc_max,
3439 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]);
3440 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3441 let scorer = ln_test_utils::TestScorer::new();
3442 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3443 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3444 let logger = ln_test_utils::TestLogger::new();
3445 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
3446 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3447 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &logger, &scorer, &random_seed_bytes);
3452 fn unannounced_path_test() {
3453 // We should be able to send a payment to a destination without any help of a routing graph
3454 // if we have a channel with a common counterparty that appears in the first and last hop
3456 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3458 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3459 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3460 assert_eq!(route.paths[0].hops.len(), 2);
3462 assert_eq!(route.paths[0].hops[0].pubkey, middle_node_id);
3463 assert_eq!(route.paths[0].hops[0].short_channel_id, 42);
3464 assert_eq!(route.paths[0].hops[0].fee_msat, 1001);
3465 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (8 << 4) | 1);
3466 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &[0b11]);
3467 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3469 assert_eq!(route.paths[0].hops[1].pubkey, target_node_id);
3470 assert_eq!(route.paths[0].hops[1].short_channel_id, 8);
3471 assert_eq!(route.paths[0].hops[1].fee_msat, 1000000);
3472 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
3473 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3474 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3478 fn overflow_unannounced_path_test_liquidity_underflow() {
3479 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3480 // the last-hop had a fee which overflowed a u64, we'd panic.
3481 // This was due to us adding the first-hop from us unconditionally, causing us to think
3482 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3483 // In this test, we previously hit a subtraction underflow due to having less available
3484 // liquidity at the last hop than 0.
3485 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());
3489 fn overflow_unannounced_path_test_feerate_overflow() {
3490 // This tests for the same case as above, except instead of hitting a subtraction
3491 // underflow, we hit a case where the fee charged at a hop overflowed.
3492 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());
3496 fn available_amount_while_routing_test() {
3497 // Tests whether we choose the correct available channel amount while routing.
3499 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3500 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3501 let scorer = ln_test_utils::TestScorer::new();
3502 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3503 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3504 let config = UserConfig::default();
3505 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
3507 // We will use a simple single-path route from
3508 // our node to node2 via node0: channels {1, 3}.
3510 // First disable all other paths.
3511 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3512 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3513 short_channel_id: 2,
3516 cltv_expiry_delta: 0,
3517 htlc_minimum_msat: 0,
3518 htlc_maximum_msat: 100_000,
3520 fee_proportional_millionths: 0,
3521 excess_data: Vec::new()
3523 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3524 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3525 short_channel_id: 12,
3528 cltv_expiry_delta: 0,
3529 htlc_minimum_msat: 0,
3530 htlc_maximum_msat: 100_000,
3532 fee_proportional_millionths: 0,
3533 excess_data: Vec::new()
3536 // Make the first channel (#1) very permissive,
3537 // and we will be testing all limits on the second channel.
3538 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3539 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3540 short_channel_id: 1,
3543 cltv_expiry_delta: 0,
3544 htlc_minimum_msat: 0,
3545 htlc_maximum_msat: 1_000_000_000,
3547 fee_proportional_millionths: 0,
3548 excess_data: Vec::new()
3551 // First, let's see if routing works if we have absolutely no idea about the available amount.
3552 // In this case, it should be set to 250_000 sats.
3553 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3554 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3555 short_channel_id: 3,
3558 cltv_expiry_delta: 0,
3559 htlc_minimum_msat: 0,
3560 htlc_maximum_msat: 250_000_000,
3562 fee_proportional_millionths: 0,
3563 excess_data: Vec::new()
3567 // Attempt to route more than available results in a failure.
3568 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3569 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3570 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3571 } else { panic!(); }
3575 // Now, attempt to route an exact amount we have should be fine.
3576 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3577 assert_eq!(route.paths.len(), 1);
3578 let path = route.paths.last().unwrap();
3579 assert_eq!(path.hops.len(), 2);
3580 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3581 assert_eq!(path.final_value_msat(), 250_000_000);
3584 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3585 // Disable channel #1 and use another first hop.
3586 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3587 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3588 short_channel_id: 1,
3591 cltv_expiry_delta: 0,
3592 htlc_minimum_msat: 0,
3593 htlc_maximum_msat: 1_000_000_000,
3595 fee_proportional_millionths: 0,
3596 excess_data: Vec::new()
3599 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3600 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3603 // Attempt to route more than available results in a failure.
3604 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3605 &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3606 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3607 } else { panic!(); }
3611 // Now, attempt to route an exact amount we have should be fine.
3612 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3613 assert_eq!(route.paths.len(), 1);
3614 let path = route.paths.last().unwrap();
3615 assert_eq!(path.hops.len(), 2);
3616 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3617 assert_eq!(path.final_value_msat(), 200_000_000);
3620 // Enable channel #1 back.
3621 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3622 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3623 short_channel_id: 1,
3626 cltv_expiry_delta: 0,
3627 htlc_minimum_msat: 0,
3628 htlc_maximum_msat: 1_000_000_000,
3630 fee_proportional_millionths: 0,
3631 excess_data: Vec::new()
3635 // Now let's see if routing works if we know only htlc_maximum_msat.
3636 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3637 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3638 short_channel_id: 3,
3641 cltv_expiry_delta: 0,
3642 htlc_minimum_msat: 0,
3643 htlc_maximum_msat: 15_000,
3645 fee_proportional_millionths: 0,
3646 excess_data: Vec::new()
3650 // Attempt to route more than available results in a failure.
3651 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3652 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3653 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3654 } else { panic!(); }
3658 // Now, attempt to route an exact amount we have should be fine.
3659 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3660 assert_eq!(route.paths.len(), 1);
3661 let path = route.paths.last().unwrap();
3662 assert_eq!(path.hops.len(), 2);
3663 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3664 assert_eq!(path.final_value_msat(), 15_000);
3667 // Now let's see if routing works if we know only capacity from the UTXO.
3669 // We can't change UTXO capacity on the fly, so we'll disable
3670 // the existing channel and add another one with the capacity we need.
3671 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3672 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3673 short_channel_id: 3,
3676 cltv_expiry_delta: 0,
3677 htlc_minimum_msat: 0,
3678 htlc_maximum_msat: MAX_VALUE_MSAT,
3680 fee_proportional_millionths: 0,
3681 excess_data: Vec::new()
3684 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3685 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3686 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3687 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3688 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3690 *chain_monitor.utxo_ret.lock().unwrap() =
3691 UtxoResult::Sync(Ok(TxOut { value: 15, script_pubkey: good_script.clone() }));
3692 gossip_sync.add_utxo_lookup(Some(chain_monitor));
3694 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3695 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3696 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3697 short_channel_id: 333,
3700 cltv_expiry_delta: (3 << 4) | 1,
3701 htlc_minimum_msat: 0,
3702 htlc_maximum_msat: 15_000,
3704 fee_proportional_millionths: 0,
3705 excess_data: Vec::new()
3707 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3708 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3709 short_channel_id: 333,
3712 cltv_expiry_delta: (3 << 4) | 2,
3713 htlc_minimum_msat: 0,
3714 htlc_maximum_msat: 15_000,
3716 fee_proportional_millionths: 0,
3717 excess_data: Vec::new()
3721 // Attempt to route more than available results in a failure.
3722 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3723 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3724 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3725 } else { panic!(); }
3729 // Now, attempt to route an exact amount we have should be fine.
3730 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3731 assert_eq!(route.paths.len(), 1);
3732 let path = route.paths.last().unwrap();
3733 assert_eq!(path.hops.len(), 2);
3734 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3735 assert_eq!(path.final_value_msat(), 15_000);
3738 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3739 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3740 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3741 short_channel_id: 333,
3744 cltv_expiry_delta: 0,
3745 htlc_minimum_msat: 0,
3746 htlc_maximum_msat: 10_000,
3748 fee_proportional_millionths: 0,
3749 excess_data: Vec::new()
3753 // Attempt to route more than available results in a failure.
3754 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3755 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3756 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3757 } else { panic!(); }
3761 // Now, attempt to route an exact amount we have should be fine.
3762 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3763 assert_eq!(route.paths.len(), 1);
3764 let path = route.paths.last().unwrap();
3765 assert_eq!(path.hops.len(), 2);
3766 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3767 assert_eq!(path.final_value_msat(), 10_000);
3772 fn available_liquidity_last_hop_test() {
3773 // Check that available liquidity properly limits the path even when only
3774 // one of the latter hops is limited.
3775 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3776 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3777 let scorer = ln_test_utils::TestScorer::new();
3778 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3779 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3780 let config = UserConfig::default();
3781 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
3783 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3784 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3785 // Total capacity: 50 sats.
3787 // Disable other potential paths.
3788 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3789 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3790 short_channel_id: 2,
3793 cltv_expiry_delta: 0,
3794 htlc_minimum_msat: 0,
3795 htlc_maximum_msat: 100_000,
3797 fee_proportional_millionths: 0,
3798 excess_data: Vec::new()
3800 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3801 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3802 short_channel_id: 7,
3805 cltv_expiry_delta: 0,
3806 htlc_minimum_msat: 0,
3807 htlc_maximum_msat: 100_000,
3809 fee_proportional_millionths: 0,
3810 excess_data: Vec::new()
3815 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3816 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3817 short_channel_id: 12,
3820 cltv_expiry_delta: 0,
3821 htlc_minimum_msat: 0,
3822 htlc_maximum_msat: 100_000,
3824 fee_proportional_millionths: 0,
3825 excess_data: Vec::new()
3827 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3828 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3829 short_channel_id: 13,
3832 cltv_expiry_delta: 0,
3833 htlc_minimum_msat: 0,
3834 htlc_maximum_msat: 100_000,
3836 fee_proportional_millionths: 0,
3837 excess_data: Vec::new()
3840 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3841 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3842 short_channel_id: 6,
3845 cltv_expiry_delta: 0,
3846 htlc_minimum_msat: 0,
3847 htlc_maximum_msat: 50_000,
3849 fee_proportional_millionths: 0,
3850 excess_data: Vec::new()
3852 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3853 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3854 short_channel_id: 11,
3857 cltv_expiry_delta: 0,
3858 htlc_minimum_msat: 0,
3859 htlc_maximum_msat: 100_000,
3861 fee_proportional_millionths: 0,
3862 excess_data: Vec::new()
3865 // Attempt to route more than available results in a failure.
3866 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3867 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3868 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3869 } else { panic!(); }
3873 // Now, attempt to route 49 sats (just a bit below the capacity).
3874 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3875 assert_eq!(route.paths.len(), 1);
3876 let mut total_amount_paid_msat = 0;
3877 for path in &route.paths {
3878 assert_eq!(path.hops.len(), 4);
3879 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
3880 total_amount_paid_msat += path.final_value_msat();
3882 assert_eq!(total_amount_paid_msat, 49_000);
3886 // Attempt to route an exact amount is also fine
3887 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3888 assert_eq!(route.paths.len(), 1);
3889 let mut total_amount_paid_msat = 0;
3890 for path in &route.paths {
3891 assert_eq!(path.hops.len(), 4);
3892 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
3893 total_amount_paid_msat += path.final_value_msat();
3895 assert_eq!(total_amount_paid_msat, 50_000);
3900 fn ignore_fee_first_hop_test() {
3901 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3902 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3903 let scorer = ln_test_utils::TestScorer::new();
3904 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3905 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3906 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3908 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3909 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3910 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3911 short_channel_id: 1,
3914 cltv_expiry_delta: 0,
3915 htlc_minimum_msat: 0,
3916 htlc_maximum_msat: 100_000,
3917 fee_base_msat: 1_000_000,
3918 fee_proportional_millionths: 0,
3919 excess_data: Vec::new()
3921 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3922 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3923 short_channel_id: 3,
3926 cltv_expiry_delta: 0,
3927 htlc_minimum_msat: 0,
3928 htlc_maximum_msat: 50_000,
3930 fee_proportional_millionths: 0,
3931 excess_data: Vec::new()
3935 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3936 assert_eq!(route.paths.len(), 1);
3937 let mut total_amount_paid_msat = 0;
3938 for path in &route.paths {
3939 assert_eq!(path.hops.len(), 2);
3940 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
3941 total_amount_paid_msat += path.final_value_msat();
3943 assert_eq!(total_amount_paid_msat, 50_000);
3948 fn simple_mpp_route_test() {
3949 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3950 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3951 let scorer = ln_test_utils::TestScorer::new();
3952 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3953 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3954 let config = UserConfig::default();
3955 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
3956 .with_features(channelmanager::provided_invoice_features(&config));
3958 // We need a route consisting of 3 paths:
3959 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3960 // To achieve this, the amount being transferred should be around
3961 // the total capacity of these 3 paths.
3963 // First, we set limits on these (previously unlimited) channels.
3964 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3966 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3967 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3968 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3969 short_channel_id: 1,
3972 cltv_expiry_delta: 0,
3973 htlc_minimum_msat: 0,
3974 htlc_maximum_msat: 100_000,
3976 fee_proportional_millionths: 0,
3977 excess_data: Vec::new()
3979 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3980 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3981 short_channel_id: 3,
3984 cltv_expiry_delta: 0,
3985 htlc_minimum_msat: 0,
3986 htlc_maximum_msat: 50_000,
3988 fee_proportional_millionths: 0,
3989 excess_data: Vec::new()
3992 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3993 // (total limit 60).
3994 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3996 short_channel_id: 12,
3999 cltv_expiry_delta: 0,
4000 htlc_minimum_msat: 0,
4001 htlc_maximum_msat: 60_000,
4003 fee_proportional_millionths: 0,
4004 excess_data: Vec::new()
4006 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4008 short_channel_id: 13,
4011 cltv_expiry_delta: 0,
4012 htlc_minimum_msat: 0,
4013 htlc_maximum_msat: 60_000,
4015 fee_proportional_millionths: 0,
4016 excess_data: Vec::new()
4019 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4020 // (total capacity 180 sats).
4021 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4022 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4023 short_channel_id: 2,
4026 cltv_expiry_delta: 0,
4027 htlc_minimum_msat: 0,
4028 htlc_maximum_msat: 200_000,
4030 fee_proportional_millionths: 0,
4031 excess_data: Vec::new()
4033 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4034 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4035 short_channel_id: 4,
4038 cltv_expiry_delta: 0,
4039 htlc_minimum_msat: 0,
4040 htlc_maximum_msat: 180_000,
4042 fee_proportional_millionths: 0,
4043 excess_data: Vec::new()
4047 // Attempt to route more than available results in a failure.
4048 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4049 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42,
4050 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4051 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4052 } else { panic!(); }
4056 // Attempt to route while setting max_path_count to 0 results in a failure.
4057 let zero_payment_params = payment_params.clone().with_max_path_count(0);
4058 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4059 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100, 42,
4060 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4061 assert_eq!(err, "Can't find a route with no paths allowed.");
4062 } else { panic!(); }
4066 // Attempt to route while setting max_path_count to 3 results in a failure.
4067 // This is the case because the minimal_value_contribution_msat would require each path
4068 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4069 let fail_payment_params = payment_params.clone().with_max_path_count(3);
4070 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4071 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000, 42,
4072 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4073 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4074 } else { panic!(); }
4078 // Now, attempt to route 250 sats (just a bit below the capacity).
4079 // Our algorithm should provide us with these 3 paths.
4080 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4081 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4082 assert_eq!(route.paths.len(), 3);
4083 let mut total_amount_paid_msat = 0;
4084 for path in &route.paths {
4085 assert_eq!(path.hops.len(), 2);
4086 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4087 total_amount_paid_msat += path.final_value_msat();
4089 assert_eq!(total_amount_paid_msat, 250_000);
4093 // Attempt to route an exact amount is also fine
4094 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4095 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4096 assert_eq!(route.paths.len(), 3);
4097 let mut total_amount_paid_msat = 0;
4098 for path in &route.paths {
4099 assert_eq!(path.hops.len(), 2);
4100 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4101 total_amount_paid_msat += path.final_value_msat();
4103 assert_eq!(total_amount_paid_msat, 290_000);
4108 fn long_mpp_route_test() {
4109 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4110 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4111 let scorer = ln_test_utils::TestScorer::new();
4112 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4113 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4114 let config = UserConfig::default();
4115 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4117 // We need a route consisting of 3 paths:
4118 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4119 // Note that these paths overlap (channels 5, 12, 13).
4120 // We will route 300 sats.
4121 // Each path will have 100 sats capacity, those channels which
4122 // are used twice will have 200 sats capacity.
4124 // Disable other potential paths.
4125 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4126 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4127 short_channel_id: 2,
4130 cltv_expiry_delta: 0,
4131 htlc_minimum_msat: 0,
4132 htlc_maximum_msat: 100_000,
4134 fee_proportional_millionths: 0,
4135 excess_data: Vec::new()
4137 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4138 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4139 short_channel_id: 7,
4142 cltv_expiry_delta: 0,
4143 htlc_minimum_msat: 0,
4144 htlc_maximum_msat: 100_000,
4146 fee_proportional_millionths: 0,
4147 excess_data: Vec::new()
4150 // Path via {node0, node2} is channels {1, 3, 5}.
4151 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4152 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4153 short_channel_id: 1,
4156 cltv_expiry_delta: 0,
4157 htlc_minimum_msat: 0,
4158 htlc_maximum_msat: 100_000,
4160 fee_proportional_millionths: 0,
4161 excess_data: Vec::new()
4163 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4164 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4165 short_channel_id: 3,
4168 cltv_expiry_delta: 0,
4169 htlc_minimum_msat: 0,
4170 htlc_maximum_msat: 100_000,
4172 fee_proportional_millionths: 0,
4173 excess_data: Vec::new()
4176 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4177 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4178 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4179 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4180 short_channel_id: 5,
4183 cltv_expiry_delta: 0,
4184 htlc_minimum_msat: 0,
4185 htlc_maximum_msat: 200_000,
4187 fee_proportional_millionths: 0,
4188 excess_data: Vec::new()
4191 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4192 // Add 100 sats to the capacities of {12, 13}, because these channels
4193 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4194 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4195 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4196 short_channel_id: 12,
4199 cltv_expiry_delta: 0,
4200 htlc_minimum_msat: 0,
4201 htlc_maximum_msat: 200_000,
4203 fee_proportional_millionths: 0,
4204 excess_data: Vec::new()
4206 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4207 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4208 short_channel_id: 13,
4211 cltv_expiry_delta: 0,
4212 htlc_minimum_msat: 0,
4213 htlc_maximum_msat: 200_000,
4215 fee_proportional_millionths: 0,
4216 excess_data: Vec::new()
4219 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4220 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4221 short_channel_id: 6,
4224 cltv_expiry_delta: 0,
4225 htlc_minimum_msat: 0,
4226 htlc_maximum_msat: 100_000,
4228 fee_proportional_millionths: 0,
4229 excess_data: Vec::new()
4231 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4232 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4233 short_channel_id: 11,
4236 cltv_expiry_delta: 0,
4237 htlc_minimum_msat: 0,
4238 htlc_maximum_msat: 100_000,
4240 fee_proportional_millionths: 0,
4241 excess_data: Vec::new()
4244 // Path via {node7, node2} is channels {12, 13, 5}.
4245 // We already limited them to 200 sats (they are used twice for 100 sats).
4246 // Nothing to do here.
4249 // Attempt to route more than available results in a failure.
4250 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4251 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4252 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4253 } else { panic!(); }
4257 // Now, attempt to route 300 sats (exact amount we can route).
4258 // Our algorithm should provide us with these 3 paths, 100 sats each.
4259 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4260 assert_eq!(route.paths.len(), 3);
4262 let mut total_amount_paid_msat = 0;
4263 for path in &route.paths {
4264 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4265 total_amount_paid_msat += path.final_value_msat();
4267 assert_eq!(total_amount_paid_msat, 300_000);
4273 fn mpp_cheaper_route_test() {
4274 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4275 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4276 let scorer = ln_test_utils::TestScorer::new();
4277 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4278 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4279 let config = UserConfig::default();
4280 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4282 // This test checks that if we have two cheaper paths and one more expensive path,
4283 // so that liquidity-wise any 2 of 3 combination is sufficient,
4284 // two cheaper paths will be taken.
4285 // These paths have equal available liquidity.
4287 // We need a combination of 3 paths:
4288 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4289 // Note that these paths overlap (channels 5, 12, 13).
4290 // Each path will have 100 sats capacity, those channels which
4291 // are used twice will have 200 sats capacity.
4293 // Disable other potential paths.
4294 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4295 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4296 short_channel_id: 2,
4299 cltv_expiry_delta: 0,
4300 htlc_minimum_msat: 0,
4301 htlc_maximum_msat: 100_000,
4303 fee_proportional_millionths: 0,
4304 excess_data: Vec::new()
4306 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4307 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4308 short_channel_id: 7,
4311 cltv_expiry_delta: 0,
4312 htlc_minimum_msat: 0,
4313 htlc_maximum_msat: 100_000,
4315 fee_proportional_millionths: 0,
4316 excess_data: Vec::new()
4319 // Path via {node0, node2} is channels {1, 3, 5}.
4320 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4321 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4322 short_channel_id: 1,
4325 cltv_expiry_delta: 0,
4326 htlc_minimum_msat: 0,
4327 htlc_maximum_msat: 100_000,
4329 fee_proportional_millionths: 0,
4330 excess_data: Vec::new()
4332 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4333 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4334 short_channel_id: 3,
4337 cltv_expiry_delta: 0,
4338 htlc_minimum_msat: 0,
4339 htlc_maximum_msat: 100_000,
4341 fee_proportional_millionths: 0,
4342 excess_data: Vec::new()
4345 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4346 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4347 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4348 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4349 short_channel_id: 5,
4352 cltv_expiry_delta: 0,
4353 htlc_minimum_msat: 0,
4354 htlc_maximum_msat: 200_000,
4356 fee_proportional_millionths: 0,
4357 excess_data: Vec::new()
4360 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4361 // Add 100 sats to the capacities of {12, 13}, because these channels
4362 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4363 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4364 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4365 short_channel_id: 12,
4368 cltv_expiry_delta: 0,
4369 htlc_minimum_msat: 0,
4370 htlc_maximum_msat: 200_000,
4372 fee_proportional_millionths: 0,
4373 excess_data: Vec::new()
4375 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4376 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4377 short_channel_id: 13,
4380 cltv_expiry_delta: 0,
4381 htlc_minimum_msat: 0,
4382 htlc_maximum_msat: 200_000,
4384 fee_proportional_millionths: 0,
4385 excess_data: Vec::new()
4388 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4390 short_channel_id: 6,
4393 cltv_expiry_delta: 0,
4394 htlc_minimum_msat: 0,
4395 htlc_maximum_msat: 100_000,
4396 fee_base_msat: 1_000,
4397 fee_proportional_millionths: 0,
4398 excess_data: Vec::new()
4400 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4401 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4402 short_channel_id: 11,
4405 cltv_expiry_delta: 0,
4406 htlc_minimum_msat: 0,
4407 htlc_maximum_msat: 100_000,
4409 fee_proportional_millionths: 0,
4410 excess_data: Vec::new()
4413 // Path via {node7, node2} is channels {12, 13, 5}.
4414 // We already limited them to 200 sats (they are used twice for 100 sats).
4415 // Nothing to do here.
4418 // Now, attempt to route 180 sats.
4419 // Our algorithm should provide us with these 2 paths.
4420 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4421 assert_eq!(route.paths.len(), 2);
4423 let mut total_value_transferred_msat = 0;
4424 let mut total_paid_msat = 0;
4425 for path in &route.paths {
4426 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4427 total_value_transferred_msat += path.final_value_msat();
4428 for hop in &path.hops {
4429 total_paid_msat += hop.fee_msat;
4432 // If we paid fee, this would be higher.
4433 assert_eq!(total_value_transferred_msat, 180_000);
4434 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4435 assert_eq!(total_fees_paid, 0);
4440 fn fees_on_mpp_route_test() {
4441 // This test makes sure that MPP algorithm properly takes into account
4442 // fees charged on the channels, by making the fees impactful:
4443 // if the fee is not properly accounted for, the behavior is different.
4444 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4445 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4446 let scorer = ln_test_utils::TestScorer::new();
4447 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4448 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4449 let config = UserConfig::default();
4450 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4452 // We need a route consisting of 2 paths:
4453 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4454 // We will route 200 sats, Each path will have 100 sats capacity.
4456 // This test is not particularly stable: e.g.,
4457 // there's a way to route via {node0, node2, node4}.
4458 // It works while pathfinding is deterministic, but can be broken otherwise.
4459 // It's fine to ignore this concern for now.
4461 // Disable other potential paths.
4462 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4464 short_channel_id: 2,
4467 cltv_expiry_delta: 0,
4468 htlc_minimum_msat: 0,
4469 htlc_maximum_msat: 100_000,
4471 fee_proportional_millionths: 0,
4472 excess_data: Vec::new()
4475 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4477 short_channel_id: 7,
4480 cltv_expiry_delta: 0,
4481 htlc_minimum_msat: 0,
4482 htlc_maximum_msat: 100_000,
4484 fee_proportional_millionths: 0,
4485 excess_data: Vec::new()
4488 // Path via {node0, node2} is channels {1, 3, 5}.
4489 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4490 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4491 short_channel_id: 1,
4494 cltv_expiry_delta: 0,
4495 htlc_minimum_msat: 0,
4496 htlc_maximum_msat: 100_000,
4498 fee_proportional_millionths: 0,
4499 excess_data: Vec::new()
4501 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4502 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4503 short_channel_id: 3,
4506 cltv_expiry_delta: 0,
4507 htlc_minimum_msat: 0,
4508 htlc_maximum_msat: 100_000,
4510 fee_proportional_millionths: 0,
4511 excess_data: Vec::new()
4514 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4515 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4516 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4517 short_channel_id: 5,
4520 cltv_expiry_delta: 0,
4521 htlc_minimum_msat: 0,
4522 htlc_maximum_msat: 100_000,
4524 fee_proportional_millionths: 0,
4525 excess_data: Vec::new()
4528 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4529 // All channels should be 100 sats capacity. But for the fee experiment,
4530 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4531 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4532 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4533 // so no matter how large are other channels,
4534 // the whole path will be limited by 100 sats with just these 2 conditions:
4535 // - channel 12 capacity is 250 sats
4536 // - fee for channel 6 is 150 sats
4537 // Let's test this by enforcing these 2 conditions and removing other limits.
4538 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4539 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4540 short_channel_id: 12,
4543 cltv_expiry_delta: 0,
4544 htlc_minimum_msat: 0,
4545 htlc_maximum_msat: 250_000,
4547 fee_proportional_millionths: 0,
4548 excess_data: Vec::new()
4550 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4551 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4552 short_channel_id: 13,
4555 cltv_expiry_delta: 0,
4556 htlc_minimum_msat: 0,
4557 htlc_maximum_msat: MAX_VALUE_MSAT,
4559 fee_proportional_millionths: 0,
4560 excess_data: Vec::new()
4563 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4564 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4565 short_channel_id: 6,
4568 cltv_expiry_delta: 0,
4569 htlc_minimum_msat: 0,
4570 htlc_maximum_msat: MAX_VALUE_MSAT,
4571 fee_base_msat: 150_000,
4572 fee_proportional_millionths: 0,
4573 excess_data: Vec::new()
4575 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4576 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4577 short_channel_id: 11,
4580 cltv_expiry_delta: 0,
4581 htlc_minimum_msat: 0,
4582 htlc_maximum_msat: MAX_VALUE_MSAT,
4584 fee_proportional_millionths: 0,
4585 excess_data: Vec::new()
4589 // Attempt to route more than available results in a failure.
4590 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4591 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4592 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4593 } else { panic!(); }
4597 // Now, attempt to route 200 sats (exact amount we can route).
4598 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4599 assert_eq!(route.paths.len(), 2);
4601 let mut total_amount_paid_msat = 0;
4602 for path in &route.paths {
4603 assert_eq!(path.hops.last().unwrap().pubkey, nodes[3]);
4604 total_amount_paid_msat += path.final_value_msat();
4606 assert_eq!(total_amount_paid_msat, 200_000);
4607 assert_eq!(route.get_total_fees(), 150_000);
4612 fn mpp_with_last_hops() {
4613 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4614 // via a single last-hop route hint, we'd fail to route if we first collected routes
4615 // totaling close but not quite enough to fund the full payment.
4617 // This was because we considered last-hop hints to have exactly the sought payment amount
4618 // instead of the amount we were trying to collect, needlessly limiting our path searching
4619 // at the very first hop.
4621 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4622 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4623 // to only have the remaining to-collect amount in available liquidity.
4625 // This bug appeared in production in some specific channel configurations.
4626 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4627 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4628 let scorer = ln_test_utils::TestScorer::new();
4629 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4630 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4631 let config = UserConfig::default();
4632 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42).with_features(channelmanager::provided_invoice_features(&config))
4633 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4634 src_node_id: nodes[2],
4635 short_channel_id: 42,
4636 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4637 cltv_expiry_delta: 42,
4638 htlc_minimum_msat: None,
4639 htlc_maximum_msat: None,
4640 }])]).with_max_channel_saturation_power_of_half(0);
4642 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4643 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4644 // would first use the no-fee route and then fail to find a path along the second route as
4645 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4646 // under 5% of our payment amount.
4647 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4648 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4649 short_channel_id: 1,
4652 cltv_expiry_delta: (5 << 4) | 5,
4653 htlc_minimum_msat: 0,
4654 htlc_maximum_msat: 99_000,
4655 fee_base_msat: u32::max_value(),
4656 fee_proportional_millionths: u32::max_value(),
4657 excess_data: Vec::new()
4659 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4660 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4661 short_channel_id: 2,
4664 cltv_expiry_delta: (5 << 4) | 3,
4665 htlc_minimum_msat: 0,
4666 htlc_maximum_msat: 99_000,
4667 fee_base_msat: u32::max_value(),
4668 fee_proportional_millionths: u32::max_value(),
4669 excess_data: Vec::new()
4671 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4672 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4673 short_channel_id: 4,
4676 cltv_expiry_delta: (4 << 4) | 1,
4677 htlc_minimum_msat: 0,
4678 htlc_maximum_msat: MAX_VALUE_MSAT,
4680 fee_proportional_millionths: 0,
4681 excess_data: Vec::new()
4683 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4684 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4685 short_channel_id: 13,
4687 flags: 0|2, // Channel disabled
4688 cltv_expiry_delta: (13 << 4) | 1,
4689 htlc_minimum_msat: 0,
4690 htlc_maximum_msat: MAX_VALUE_MSAT,
4692 fee_proportional_millionths: 2000000,
4693 excess_data: Vec::new()
4696 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4698 let mut route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4699 assert_eq!(route.paths.len(), 2);
4700 route.paths.sort_by_key(|path| path.hops[0].short_channel_id);
4701 // Paths are manually ordered ordered by SCID, so:
4702 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4703 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
4704 assert_eq!(route.paths[0].hops[0].short_channel_id, 1);
4705 assert_eq!(route.paths[0].hops[0].fee_msat, 0);
4706 assert_eq!(route.paths[0].hops[2].fee_msat, 99_000);
4707 assert_eq!(route.paths[1].hops[0].short_channel_id, 2);
4708 assert_eq!(route.paths[1].hops[0].fee_msat, 1);
4709 assert_eq!(route.paths[1].hops[2].fee_msat, 1_000);
4710 assert_eq!(route.get_total_fees(), 1);
4711 assert_eq!(route.get_total_amount(), 100_000);
4715 fn drop_lowest_channel_mpp_route_test() {
4716 // This test checks that low-capacity channel is dropped when after
4717 // path finding we realize that we found more capacity than we need.
4718 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4719 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4720 let scorer = ln_test_utils::TestScorer::new();
4721 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4722 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4723 let config = UserConfig::default();
4724 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config))
4725 .with_max_channel_saturation_power_of_half(0);
4727 // We need a route consisting of 3 paths:
4728 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4730 // The first and the second paths should be sufficient, but the third should be
4731 // cheaper, so that we select it but drop later.
4733 // First, we set limits on these (previously unlimited) channels.
4734 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4736 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4737 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4739 short_channel_id: 1,
4742 cltv_expiry_delta: 0,
4743 htlc_minimum_msat: 0,
4744 htlc_maximum_msat: 100_000,
4746 fee_proportional_millionths: 0,
4747 excess_data: Vec::new()
4749 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4750 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4751 short_channel_id: 3,
4754 cltv_expiry_delta: 0,
4755 htlc_minimum_msat: 0,
4756 htlc_maximum_msat: 50_000,
4758 fee_proportional_millionths: 0,
4759 excess_data: Vec::new()
4762 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4763 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4764 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4765 short_channel_id: 12,
4768 cltv_expiry_delta: 0,
4769 htlc_minimum_msat: 0,
4770 htlc_maximum_msat: 60_000,
4772 fee_proportional_millionths: 0,
4773 excess_data: Vec::new()
4775 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4776 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4777 short_channel_id: 13,
4780 cltv_expiry_delta: 0,
4781 htlc_minimum_msat: 0,
4782 htlc_maximum_msat: 60_000,
4784 fee_proportional_millionths: 0,
4785 excess_data: Vec::new()
4788 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4789 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4790 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4791 short_channel_id: 2,
4794 cltv_expiry_delta: 0,
4795 htlc_minimum_msat: 0,
4796 htlc_maximum_msat: 20_000,
4798 fee_proportional_millionths: 0,
4799 excess_data: Vec::new()
4801 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4802 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4803 short_channel_id: 4,
4806 cltv_expiry_delta: 0,
4807 htlc_minimum_msat: 0,
4808 htlc_maximum_msat: 20_000,
4810 fee_proportional_millionths: 0,
4811 excess_data: Vec::new()
4815 // Attempt to route more than available results in a failure.
4816 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4817 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4818 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4819 } else { panic!(); }
4823 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4824 // Our algorithm should provide us with these 3 paths.
4825 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4826 assert_eq!(route.paths.len(), 3);
4827 let mut total_amount_paid_msat = 0;
4828 for path in &route.paths {
4829 assert_eq!(path.hops.len(), 2);
4830 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4831 total_amount_paid_msat += path.final_value_msat();
4833 assert_eq!(total_amount_paid_msat, 125_000);
4837 // Attempt to route without the last small cheap channel
4838 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4839 assert_eq!(route.paths.len(), 2);
4840 let mut total_amount_paid_msat = 0;
4841 for path in &route.paths {
4842 assert_eq!(path.hops.len(), 2);
4843 assert_eq!(path.hops.last().unwrap().pubkey, nodes[2]);
4844 total_amount_paid_msat += path.final_value_msat();
4846 assert_eq!(total_amount_paid_msat, 90_000);
4851 fn min_criteria_consistency() {
4852 // Test that we don't use an inconsistent metric between updating and walking nodes during
4853 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4854 // was updated with a different criterion from the heap sorting, resulting in loops in
4855 // calculated paths. We test for that specific case here.
4857 // We construct a network that looks like this:
4859 // node2 -1(3)2- node3
4863 // node1 -1(5)2- node4 -1(1)2- node6
4869 // We create a loop on the side of our real path - our destination is node 6, with a
4870 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4871 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4872 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4873 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4874 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4875 // "previous hop" being set to node 3, creating a loop in the path.
4876 let secp_ctx = Secp256k1::new();
4877 let logger = Arc::new(ln_test_utils::TestLogger::new());
4878 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
4879 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
4880 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4881 let scorer = ln_test_utils::TestScorer::new();
4882 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4883 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4884 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
4886 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4887 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4888 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4889 short_channel_id: 6,
4892 cltv_expiry_delta: (6 << 4) | 0,
4893 htlc_minimum_msat: 0,
4894 htlc_maximum_msat: MAX_VALUE_MSAT,
4896 fee_proportional_millionths: 0,
4897 excess_data: Vec::new()
4899 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4901 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4902 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4903 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4904 short_channel_id: 5,
4907 cltv_expiry_delta: (5 << 4) | 0,
4908 htlc_minimum_msat: 0,
4909 htlc_maximum_msat: MAX_VALUE_MSAT,
4911 fee_proportional_millionths: 0,
4912 excess_data: Vec::new()
4914 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4916 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4917 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4918 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4919 short_channel_id: 4,
4922 cltv_expiry_delta: (4 << 4) | 0,
4923 htlc_minimum_msat: 0,
4924 htlc_maximum_msat: MAX_VALUE_MSAT,
4926 fee_proportional_millionths: 0,
4927 excess_data: Vec::new()
4929 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4931 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4932 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4933 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4934 short_channel_id: 3,
4937 cltv_expiry_delta: (3 << 4) | 0,
4938 htlc_minimum_msat: 0,
4939 htlc_maximum_msat: MAX_VALUE_MSAT,
4941 fee_proportional_millionths: 0,
4942 excess_data: Vec::new()
4944 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4946 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4947 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4948 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4949 short_channel_id: 2,
4952 cltv_expiry_delta: (2 << 4) | 0,
4953 htlc_minimum_msat: 0,
4954 htlc_maximum_msat: MAX_VALUE_MSAT,
4956 fee_proportional_millionths: 0,
4957 excess_data: Vec::new()
4960 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4961 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4962 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4963 short_channel_id: 1,
4966 cltv_expiry_delta: (1 << 4) | 0,
4967 htlc_minimum_msat: 100,
4968 htlc_maximum_msat: MAX_VALUE_MSAT,
4970 fee_proportional_millionths: 0,
4971 excess_data: Vec::new()
4973 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4976 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4977 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4978 assert_eq!(route.paths.len(), 1);
4979 assert_eq!(route.paths[0].hops.len(), 3);
4981 assert_eq!(route.paths[0].hops[0].pubkey, nodes[1]);
4982 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
4983 assert_eq!(route.paths[0].hops[0].fee_msat, 100);
4984 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (5 << 4) | 0);
4985 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(1));
4986 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(6));
4988 assert_eq!(route.paths[0].hops[1].pubkey, nodes[4]);
4989 assert_eq!(route.paths[0].hops[1].short_channel_id, 5);
4990 assert_eq!(route.paths[0].hops[1].fee_msat, 0);
4991 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, (1 << 4) | 0);
4992 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(4));
4993 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(5));
4995 assert_eq!(route.paths[0].hops[2].pubkey, nodes[6]);
4996 assert_eq!(route.paths[0].hops[2].short_channel_id, 1);
4997 assert_eq!(route.paths[0].hops[2].fee_msat, 10_000);
4998 assert_eq!(route.paths[0].hops[2].cltv_expiry_delta, 42);
4999 assert_eq!(route.paths[0].hops[2].node_features.le_flags(), &id_to_feature_flags(6));
5000 assert_eq!(route.paths[0].hops[2].channel_features.le_flags(), &id_to_feature_flags(1));
5006 fn exact_fee_liquidity_limit() {
5007 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5008 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5009 // we calculated fees on a higher value, resulting in us ignoring such paths.
5010 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5011 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5012 let scorer = ln_test_utils::TestScorer::new();
5013 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5014 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5015 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
5017 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5019 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5020 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5021 short_channel_id: 2,
5024 cltv_expiry_delta: 0,
5025 htlc_minimum_msat: 0,
5026 htlc_maximum_msat: 85_000,
5028 fee_proportional_millionths: 0,
5029 excess_data: Vec::new()
5032 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5033 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5034 short_channel_id: 12,
5037 cltv_expiry_delta: (4 << 4) | 1,
5038 htlc_minimum_msat: 0,
5039 htlc_maximum_msat: 270_000,
5041 fee_proportional_millionths: 1000000,
5042 excess_data: Vec::new()
5046 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5047 // 200% fee charged channel 13 in the 1-to-2 direction.
5048 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5049 assert_eq!(route.paths.len(), 1);
5050 assert_eq!(route.paths[0].hops.len(), 2);
5052 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5053 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5054 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5055 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5056 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5057 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5059 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5060 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5061 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5062 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5063 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), &id_to_feature_flags(3));
5064 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5069 fn htlc_max_reduction_below_min() {
5070 // Test that if, while walking the graph, we reduce the value being sent to meet an
5071 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5072 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5073 // resulting in us thinking there is no possible path, even if other paths exist.
5074 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5075 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5076 let scorer = ln_test_utils::TestScorer::new();
5077 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5078 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5079 let config = UserConfig::default();
5080 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
5082 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5083 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5084 // then try to send 90_000.
5085 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5086 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5087 short_channel_id: 2,
5090 cltv_expiry_delta: 0,
5091 htlc_minimum_msat: 0,
5092 htlc_maximum_msat: 80_000,
5094 fee_proportional_millionths: 0,
5095 excess_data: Vec::new()
5097 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5098 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5099 short_channel_id: 4,
5102 cltv_expiry_delta: (4 << 4) | 1,
5103 htlc_minimum_msat: 90_000,
5104 htlc_maximum_msat: MAX_VALUE_MSAT,
5106 fee_proportional_millionths: 0,
5107 excess_data: Vec::new()
5111 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5112 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5113 // expensive) channels 12-13 path.
5114 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5115 assert_eq!(route.paths.len(), 1);
5116 assert_eq!(route.paths[0].hops.len(), 2);
5118 assert_eq!(route.paths[0].hops[0].pubkey, nodes[7]);
5119 assert_eq!(route.paths[0].hops[0].short_channel_id, 12);
5120 assert_eq!(route.paths[0].hops[0].fee_msat, 90_000*2);
5121 assert_eq!(route.paths[0].hops[0].cltv_expiry_delta, (13 << 4) | 1);
5122 assert_eq!(route.paths[0].hops[0].node_features.le_flags(), &id_to_feature_flags(8));
5123 assert_eq!(route.paths[0].hops[0].channel_features.le_flags(), &id_to_feature_flags(12));
5125 assert_eq!(route.paths[0].hops[1].pubkey, nodes[2]);
5126 assert_eq!(route.paths[0].hops[1].short_channel_id, 13);
5127 assert_eq!(route.paths[0].hops[1].fee_msat, 90_000);
5128 assert_eq!(route.paths[0].hops[1].cltv_expiry_delta, 42);
5129 assert_eq!(route.paths[0].hops[1].node_features.le_flags(), channelmanager::provided_invoice_features(&config).le_flags());
5130 assert_eq!(route.paths[0].hops[1].channel_features.le_flags(), &id_to_feature_flags(13));
5135 fn multiple_direct_first_hops() {
5136 // Previously we'd only ever considered one first hop path per counterparty.
5137 // However, as we don't restrict users to one channel per peer, we really need to support
5138 // looking at all first hop paths.
5139 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5140 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5141 // route over multiple channels with the same first hop.
5142 let secp_ctx = Secp256k1::new();
5143 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5144 let logger = Arc::new(ln_test_utils::TestLogger::new());
5145 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
5146 let scorer = ln_test_utils::TestScorer::new();
5147 let config = UserConfig::default();
5148 let payment_params = PaymentParameters::from_node_id(nodes[0], 42).with_features(channelmanager::provided_invoice_features(&config));
5149 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5150 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5153 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5154 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
5155 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
5156 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5157 assert_eq!(route.paths.len(), 1);
5158 assert_eq!(route.paths[0].hops.len(), 1);
5160 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5161 assert_eq!(route.paths[0].hops[0].short_channel_id, 3);
5162 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5165 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5166 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5167 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5168 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5169 assert_eq!(route.paths.len(), 2);
5170 assert_eq!(route.paths[0].hops.len(), 1);
5171 assert_eq!(route.paths[1].hops.len(), 1);
5173 assert!((route.paths[0].hops[0].short_channel_id == 3 && route.paths[1].hops[0].short_channel_id == 2) ||
5174 (route.paths[0].hops[0].short_channel_id == 2 && route.paths[1].hops[0].short_channel_id == 3));
5176 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5177 assert_eq!(route.paths[0].hops[0].fee_msat, 50_000);
5179 assert_eq!(route.paths[1].hops[0].pubkey, nodes[0]);
5180 assert_eq!(route.paths[1].hops[0].fee_msat, 50_000);
5184 // If we have a bunch of outbound channels to the same node, where most are not
5185 // sufficient to pay the full payment, but one is, we should default to just using the
5186 // one single channel that has sufficient balance, avoiding MPP.
5188 // If we have several options above the 3xpayment value threshold, we should pick the
5189 // smallest of them, avoiding further fragmenting our available outbound balance to
5191 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5192 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5193 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5194 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5195 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
5196 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5197 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5198 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5199 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
5200 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5201 assert_eq!(route.paths.len(), 1);
5202 assert_eq!(route.paths[0].hops.len(), 1);
5204 assert_eq!(route.paths[0].hops[0].pubkey, nodes[0]);
5205 assert_eq!(route.paths[0].hops[0].short_channel_id, 6);
5206 assert_eq!(route.paths[0].hops[0].fee_msat, 100_000);
5211 fn prefers_shorter_route_with_higher_fees() {
5212 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5213 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5214 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5216 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5217 let scorer = ln_test_utils::TestScorer::new();
5218 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5219 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5220 let route = get_route(
5221 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5222 Arc::clone(&logger), &scorer, &random_seed_bytes
5224 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5226 assert_eq!(route.get_total_fees(), 100);
5227 assert_eq!(route.get_total_amount(), 100);
5228 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5230 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5231 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5232 let scorer = FixedPenaltyScorer::with_penalty(100);
5233 let route = get_route(
5234 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5235 Arc::clone(&logger), &scorer, &random_seed_bytes
5237 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5239 assert_eq!(route.get_total_fees(), 300);
5240 assert_eq!(route.get_total_amount(), 100);
5241 assert_eq!(path, vec![2, 4, 7, 10]);
5244 struct BadChannelScorer {
5245 short_channel_id: u64,
5249 impl Writeable for BadChannelScorer {
5250 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5252 impl Score for BadChannelScorer {
5253 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage) -> u64 {
5254 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5257 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5258 fn payment_path_successful(&mut self, _path: &Path) {}
5259 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5260 fn probe_successful(&mut self, _path: &Path) {}
5263 struct BadNodeScorer {
5268 impl Writeable for BadNodeScorer {
5269 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5272 impl Score for BadNodeScorer {
5273 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage) -> u64 {
5274 if *target == self.node_id { u64::max_value() } else { 0 }
5277 fn payment_path_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5278 fn payment_path_successful(&mut self, _path: &Path) {}
5279 fn probe_failed(&mut self, _path: &Path, _short_channel_id: u64) {}
5280 fn probe_successful(&mut self, _path: &Path) {}
5284 fn avoids_routing_through_bad_channels_and_nodes() {
5285 let (secp_ctx, network, _, _, logger) = build_graph();
5286 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5287 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5288 let network_graph = network.read_only();
5290 // A path to nodes[6] exists when no penalties are applied to any channel.
5291 let scorer = ln_test_utils::TestScorer::new();
5292 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5293 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5294 let route = get_route(
5295 &our_id, &payment_params, &network_graph, None, 100, 42,
5296 Arc::clone(&logger), &scorer, &random_seed_bytes
5298 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5300 assert_eq!(route.get_total_fees(), 100);
5301 assert_eq!(route.get_total_amount(), 100);
5302 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5304 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5305 let scorer = BadChannelScorer { short_channel_id: 6 };
5306 let route = get_route(
5307 &our_id, &payment_params, &network_graph, None, 100, 42,
5308 Arc::clone(&logger), &scorer, &random_seed_bytes
5310 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5312 assert_eq!(route.get_total_fees(), 300);
5313 assert_eq!(route.get_total_amount(), 100);
5314 assert_eq!(path, vec![2, 4, 7, 10]);
5316 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5317 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5319 &our_id, &payment_params, &network_graph, None, 100, 42,
5320 Arc::clone(&logger), &scorer, &random_seed_bytes
5322 Err(LightningError { err, .. } ) => {
5323 assert_eq!(err, "Failed to find a path to the given destination");
5325 Ok(_) => panic!("Expected error"),
5330 fn total_fees_single_path() {
5332 paths: vec![Path { hops: vec![
5334 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5335 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5336 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5339 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5340 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5341 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5344 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5345 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5346 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5348 ], blinded_tail: None }],
5349 payment_params: None,
5352 assert_eq!(route.get_total_fees(), 250);
5353 assert_eq!(route.get_total_amount(), 225);
5357 fn total_fees_multi_path() {
5359 paths: vec![Path { hops: vec![
5361 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5362 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5363 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5366 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5367 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5368 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5370 ], blinded_tail: None }, Path { hops: vec![
5372 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5373 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5374 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5377 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5378 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5379 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5381 ], blinded_tail: None }],
5382 payment_params: None,
5385 assert_eq!(route.get_total_fees(), 200);
5386 assert_eq!(route.get_total_amount(), 300);
5390 fn total_empty_route_no_panic() {
5391 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5392 // would both panic if the route was completely empty. We test to ensure they return 0
5393 // here, even though its somewhat nonsensical as a route.
5394 let route = Route { paths: Vec::new(), payment_params: None };
5396 assert_eq!(route.get_total_fees(), 0);
5397 assert_eq!(route.get_total_amount(), 0);
5401 fn limits_total_cltv_delta() {
5402 let (secp_ctx, network, _, _, logger) = build_graph();
5403 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5404 let network_graph = network.read_only();
5406 let scorer = ln_test_utils::TestScorer::new();
5408 // Make sure that generally there is at least one route available
5409 let feasible_max_total_cltv_delta = 1008;
5410 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5411 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5412 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5413 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5414 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5415 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5416 assert_ne!(path.len(), 0);
5418 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5419 let fail_max_total_cltv_delta = 23;
5420 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5421 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5422 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5424 Err(LightningError { err, .. } ) => {
5425 assert_eq!(err, "Failed to find a path to the given destination");
5427 Ok(_) => panic!("Expected error"),
5432 fn avoids_recently_failed_paths() {
5433 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
5434 // randomly inserting channels into it until we can't find a route anymore.
5435 let (secp_ctx, network, _, _, logger) = build_graph();
5436 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5437 let network_graph = network.read_only();
5439 let scorer = ln_test_utils::TestScorer::new();
5440 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5441 .with_max_path_count(1);
5442 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5443 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5445 // We should be able to find a route initially, and then after we fail a few random
5446 // channels eventually we won't be able to any longer.
5447 assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).is_ok());
5449 if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes) {
5450 for chan in route.paths[0].hops.iter() {
5451 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
5453 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
5454 % route.paths[0].hops.len();
5455 payment_params.previously_failed_channels.push(route.paths[0].hops[victim].short_channel_id);
5461 fn limits_path_length() {
5462 let (secp_ctx, network, _, _, logger) = build_line_graph();
5463 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5464 let network_graph = network.read_only();
5466 let scorer = ln_test_utils::TestScorer::new();
5467 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5468 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5470 // First check we can actually create a long route on this graph.
5471 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
5472 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0,
5473 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5474 let path = route.paths[0].hops.iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5475 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5477 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5478 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
5479 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0,
5480 Arc::clone(&logger), &scorer, &random_seed_bytes)
5482 Err(LightningError { err, .. } ) => {
5483 assert_eq!(err, "Failed to find a path to the given destination");
5485 Ok(_) => panic!("Expected error"),
5490 fn adds_and_limits_cltv_offset() {
5491 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5492 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5494 let scorer = ln_test_utils::TestScorer::new();
5496 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5497 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5498 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5499 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5500 assert_eq!(route.paths.len(), 1);
5502 let cltv_expiry_deltas_before = route.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5504 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5505 let mut route_default = route.clone();
5506 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5507 let cltv_expiry_deltas_default = route_default.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5508 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5509 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5510 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5512 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5513 let mut route_limited = route.clone();
5514 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5515 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5516 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5517 let cltv_expiry_deltas_limited = route_limited.paths[0].hops.iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5518 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5522 fn adds_plausible_cltv_offset() {
5523 let (secp_ctx, network, _, _, logger) = build_graph();
5524 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5525 let network_graph = network.read_only();
5526 let network_nodes = network_graph.nodes();
5527 let network_channels = network_graph.channels();
5528 let scorer = ln_test_utils::TestScorer::new();
5529 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5530 let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5531 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5533 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5534 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5535 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5537 let mut path_plausibility = vec![];
5539 for p in route.paths {
5540 // 1. Select random observation point
5541 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5542 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5544 prng.process_in_place(&mut random_bytes);
5545 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.hops.len());
5546 let observation_point = NodeId::from_pubkey(&p.hops.get(random_path_index).unwrap().pubkey);
5548 // 2. Calculate what CLTV expiry delta we would observe there
5549 let observed_cltv_expiry_delta: u32 = p.hops[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5551 // 3. Starting from the observation point, find candidate paths
5552 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5553 candidates.push_back((observation_point, vec![]));
5555 let mut found_plausible_candidate = false;
5557 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5558 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5559 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5560 found_plausible_candidate = true;
5561 break 'candidate_loop;
5565 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5566 for channel_id in &cur_node.channels {
5567 if let Some(channel_info) = network_channels.get(&channel_id) {
5568 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5569 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
5570 if cur_path_cltv_deltas.iter().sum::<u32>()
5571 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5572 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5573 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5574 candidates.push_back((*next_id, new_path_cltv_deltas));
5582 path_plausibility.push(found_plausible_candidate);
5584 assert!(path_plausibility.iter().all(|x| *x));
5588 fn builds_correct_path_from_hops() {
5589 let (secp_ctx, network, _, _, logger) = build_graph();
5590 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5591 let network_graph = network.read_only();
5593 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5594 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5596 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5597 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5598 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5599 &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
5600 let route_hop_pubkeys = route.paths[0].hops.iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5601 assert_eq!(hops.len(), route.paths[0].hops.len());
5602 for (idx, hop_pubkey) in hops.iter().enumerate() {
5603 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5608 fn avoids_saturating_channels() {
5609 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5610 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5612 let scorer = ProbabilisticScorer::new(Default::default(), &*network_graph, Arc::clone(&logger));
5614 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
5615 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
5616 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5617 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5618 short_channel_id: 4,
5621 cltv_expiry_delta: (4 << 4) | 1,
5622 htlc_minimum_msat: 0,
5623 htlc_maximum_msat: 250_000_000,
5625 fee_proportional_millionths: 0,
5626 excess_data: Vec::new()
5628 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5629 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5630 short_channel_id: 13,
5633 cltv_expiry_delta: (13 << 4) | 1,
5634 htlc_minimum_msat: 0,
5635 htlc_maximum_msat: 250_000_000,
5637 fee_proportional_millionths: 0,
5638 excess_data: Vec::new()
5641 let config = UserConfig::default();
5642 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
5643 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5644 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5645 // 100,000 sats is less than the available liquidity on each channel, set above.
5646 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5647 assert_eq!(route.paths.len(), 2);
5648 assert!((route.paths[0].hops[1].short_channel_id == 4 && route.paths[1].hops[1].short_channel_id == 13) ||
5649 (route.paths[1].hops[1].short_channel_id == 4 && route.paths[0].hops[1].short_channel_id == 13));
5652 #[cfg(not(feature = "no-std"))]
5653 pub(super) fn random_init_seed() -> u64 {
5654 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5655 use core::hash::{BuildHasher, Hasher};
5656 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5657 println!("Using seed of {}", seed);
5660 #[cfg(not(feature = "no-std"))]
5661 use crate::util::ser::ReadableArgs;
5664 #[cfg(not(feature = "no-std"))]
5665 fn generate_routes() {
5666 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5668 let mut d = match super::bench_utils::get_route_file() {
5675 let logger = ln_test_utils::TestLogger::new();
5676 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5677 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5678 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5680 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5681 let mut seed = random_init_seed() as usize;
5682 let nodes = graph.read_only().nodes().clone();
5683 'load_endpoints: for _ in 0..10 {
5685 seed = seed.overflowing_mul(0xdeadbeef).0;
5686 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5687 seed = seed.overflowing_mul(0xdeadbeef).0;
5688 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5689 let payment_params = PaymentParameters::from_node_id(dst, 42);
5690 let amt = seed as u64 % 200_000_000;
5691 let params = ProbabilisticScoringParameters::default();
5692 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5693 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5694 continue 'load_endpoints;
5701 #[cfg(not(feature = "no-std"))]
5702 fn generate_routes_mpp() {
5703 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5705 let mut d = match super::bench_utils::get_route_file() {
5712 let logger = ln_test_utils::TestLogger::new();
5713 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5714 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5715 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5716 let config = UserConfig::default();
5718 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5719 let mut seed = random_init_seed() as usize;
5720 let nodes = graph.read_only().nodes().clone();
5721 'load_endpoints: for _ in 0..10 {
5723 seed = seed.overflowing_mul(0xdeadbeef).0;
5724 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5725 seed = seed.overflowing_mul(0xdeadbeef).0;
5726 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5727 let payment_params = PaymentParameters::from_node_id(dst, 42).with_features(channelmanager::provided_invoice_features(&config));
5728 let amt = seed as u64 % 200_000_000;
5729 let params = ProbabilisticScoringParameters::default();
5730 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5731 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5732 continue 'load_endpoints;
5739 fn honors_manual_penalties() {
5740 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
5741 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5743 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5744 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5746 let scorer_params = ProbabilisticScoringParameters::default();
5747 let mut scorer = ProbabilisticScorer::new(scorer_params, Arc::clone(&network_graph), Arc::clone(&logger));
5749 // First check set manual penalties are returned by the scorer.
5750 let usage = ChannelUsage {
5752 inflight_htlc_msat: 0,
5753 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
5755 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
5756 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
5757 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage), 456);
5759 // Then check we can get a normal route
5760 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
5761 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5762 assert!(route.is_ok());
5764 // Then check that we can't get a route if we ban an intermediate node.
5765 scorer.add_banned(&NodeId::from_pubkey(&nodes[3]));
5766 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5767 assert!(route.is_err());
5769 // Finally make sure we can route again, when we remove the ban.
5770 scorer.remove_banned(&NodeId::from_pubkey(&nodes[3]));
5771 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5772 assert!(route.is_ok());
5776 fn blinded_route_ser() {
5777 let blinded_path_1 = BlindedPath {
5778 introduction_node_id: ln_test_utils::pubkey(42),
5779 blinding_point: ln_test_utils::pubkey(43),
5781 BlindedHop { blinded_node_id: ln_test_utils::pubkey(44), encrypted_payload: Vec::new() },
5782 BlindedHop { blinded_node_id: ln_test_utils::pubkey(45), encrypted_payload: Vec::new() }
5785 let blinded_path_2 = BlindedPath {
5786 introduction_node_id: ln_test_utils::pubkey(46),
5787 blinding_point: ln_test_utils::pubkey(47),
5789 BlindedHop { blinded_node_id: ln_test_utils::pubkey(48), encrypted_payload: Vec::new() },
5790 BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }
5793 // (De)serialize a Route with 1 blinded path out of two total paths.
5794 let mut route = Route { paths: vec![Path {
5795 hops: vec![RouteHop {
5796 pubkey: ln_test_utils::pubkey(50),
5797 node_features: NodeFeatures::empty(),
5798 short_channel_id: 42,
5799 channel_features: ChannelFeatures::empty(),
5801 cltv_expiry_delta: 0,
5803 blinded_tail: Some(BlindedTail {
5804 hops: blinded_path_1.blinded_hops,
5805 blinding_point: blinded_path_1.blinding_point,
5806 excess_final_cltv_expiry_delta: 40,
5807 final_value_msat: 100,
5809 hops: vec![RouteHop {
5810 pubkey: ln_test_utils::pubkey(51),
5811 node_features: NodeFeatures::empty(),
5812 short_channel_id: 43,
5813 channel_features: ChannelFeatures::empty(),
5815 cltv_expiry_delta: 0,
5816 }], blinded_tail: None }],
5817 payment_params: None,
5819 let encoded_route = route.encode();
5820 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
5821 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
5822 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
5824 // (De)serialize a Route with two paths, each containing a blinded tail.
5825 route.paths[1].blinded_tail = Some(BlindedTail {
5826 hops: blinded_path_2.blinded_hops,
5827 blinding_point: blinded_path_2.blinding_point,
5828 excess_final_cltv_expiry_delta: 41,
5829 final_value_msat: 101,
5831 let encoded_route = route.encode();
5832 let decoded_route: Route = Readable::read(&mut Cursor::new(&encoded_route[..])).unwrap();
5833 assert_eq!(decoded_route.paths[0].blinded_tail, route.paths[0].blinded_tail);
5834 assert_eq!(decoded_route.paths[1].blinded_tail, route.paths[1].blinded_tail);
5838 fn blinded_path_inflight_processing() {
5839 // Ensure we'll score the channel that's inbound to a blinded path's introduction node, and
5840 // account for the blinded tail's final amount_msat.
5841 let mut inflight_htlcs = InFlightHtlcs::new();
5842 let blinded_path = BlindedPath {
5843 introduction_node_id: ln_test_utils::pubkey(43),
5844 blinding_point: ln_test_utils::pubkey(48),
5845 blinded_hops: vec![BlindedHop { blinded_node_id: ln_test_utils::pubkey(49), encrypted_payload: Vec::new() }],
5848 hops: vec![RouteHop {
5849 pubkey: ln_test_utils::pubkey(42),
5850 node_features: NodeFeatures::empty(),
5851 short_channel_id: 42,
5852 channel_features: ChannelFeatures::empty(),
5854 cltv_expiry_delta: 0,
5857 pubkey: blinded_path.introduction_node_id,
5858 node_features: NodeFeatures::empty(),
5859 short_channel_id: 43,
5860 channel_features: ChannelFeatures::empty(),
5862 cltv_expiry_delta: 0,
5864 blinded_tail: Some(BlindedTail {
5865 hops: blinded_path.blinded_hops,
5866 blinding_point: blinded_path.blinding_point,
5867 excess_final_cltv_expiry_delta: 0,
5868 final_value_msat: 200,
5871 inflight_htlcs.process_path(&path, ln_test_utils::pubkey(44));
5872 assert_eq!(*inflight_htlcs.0.get(&(42, true)).unwrap(), 301);
5873 assert_eq!(*inflight_htlcs.0.get(&(43, false)).unwrap(), 201);
5877 #[cfg(all(test, not(feature = "no-std")))]
5878 pub(crate) mod bench_utils {
5880 /// Tries to open a network graph file, or panics with a URL to fetch it.
5881 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5882 let res = File::open("net_graph-2023-01-18.bin") // By default we're run in RL/lightning
5883 .or_else(|_| File::open("lightning/net_graph-2023-01-18.bin")) // We may be run manually in RL/
5884 .or_else(|_| { // Fall back to guessing based on the binary location
5885 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5886 let mut path = std::env::current_exe().unwrap();
5887 path.pop(); // lightning-...
5889 path.pop(); // debug
5890 path.pop(); // target
5891 path.push("lightning");
5892 path.push("net_graph-2023-01-18.bin");
5893 eprintln!("{}", path.to_str().unwrap());
5896 .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");
5897 #[cfg(require_route_graph_test)]
5898 return Ok(res.unwrap());
5899 #[cfg(not(require_route_graph_test))]
5904 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5907 use bitcoin::hashes::Hash;
5908 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5909 use crate::chain::transaction::OutPoint;
5910 use crate::chain::keysinterface::{EntropySource, KeysManager};
5911 use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
5912 use crate::ln::features::InvoiceFeatures;
5913 use crate::routing::gossip::NetworkGraph;
5914 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters};
5915 use crate::util::config::UserConfig;
5916 use crate::util::logger::{Logger, Record};
5917 use crate::util::ser::ReadableArgs;
5921 struct DummyLogger {}
5922 impl Logger for DummyLogger {
5923 fn log(&self, _record: &Record) {}
5926 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
5927 let mut d = bench_utils::get_route_file().unwrap();
5928 NetworkGraph::read(&mut d, logger).unwrap()
5931 fn payer_pubkey() -> PublicKey {
5932 let secp_ctx = Secp256k1::new();
5933 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5937 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5939 channel_id: [0; 32],
5940 counterparty: ChannelCounterparty {
5941 features: channelmanager::provided_init_features(&UserConfig::default()),
5943 unspendable_punishment_reserve: 0,
5944 forwarding_info: None,
5945 outbound_htlc_minimum_msat: None,
5946 outbound_htlc_maximum_msat: None,
5948 funding_txo: Some(OutPoint {
5949 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5952 short_channel_id: Some(1),
5953 inbound_scid_alias: None,
5954 outbound_scid_alias: None,
5955 channel_value_satoshis: 10_000_000,
5957 balance_msat: 10_000_000,
5958 outbound_capacity_msat: 10_000_000,
5959 next_outbound_htlc_limit_msat: 10_000_000,
5960 inbound_capacity_msat: 0,
5961 unspendable_punishment_reserve: None,
5962 confirmations_required: None,
5963 confirmations: None,
5964 force_close_spend_delay: None,
5966 is_channel_ready: true,
5969 inbound_htlc_minimum_msat: None,
5970 inbound_htlc_maximum_msat: None,
5972 feerate_sat_per_1000_weight: None,
5977 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5978 let logger = DummyLogger {};
5979 let network_graph = read_network_graph(&logger);
5980 let scorer = FixedPenaltyScorer::with_penalty(0);
5981 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5985 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5986 let logger = DummyLogger {};
5987 let network_graph = read_network_graph(&logger);
5988 let scorer = FixedPenaltyScorer::with_penalty(0);
5989 generate_routes(bench, &network_graph, scorer, channelmanager::provided_invoice_features(&UserConfig::default()));
5993 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5994 let logger = DummyLogger {};
5995 let network_graph = read_network_graph(&logger);
5996 let params = ProbabilisticScoringParameters::default();
5997 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5998 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
6002 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
6003 let logger = DummyLogger {};
6004 let network_graph = read_network_graph(&logger);
6005 let params = ProbabilisticScoringParameters::default();
6006 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
6007 generate_routes(bench, &network_graph, scorer, channelmanager::provided_invoice_features(&UserConfig::default()));
6010 fn generate_routes<S: Score>(
6011 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S,
6012 features: InvoiceFeatures
6014 let nodes = graph.read_only().nodes().clone();
6015 let payer = payer_pubkey();
6016 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
6017 let random_seed_bytes = keys_manager.get_secure_random_bytes();
6019 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
6020 let mut routes = Vec::new();
6021 let mut route_endpoints = Vec::new();
6022 let mut seed: usize = 0xdeadbeef;
6023 'load_endpoints: for _ in 0..150 {
6026 let src = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
6028 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
6029 let params = PaymentParameters::from_node_id(dst, 42).with_features(features.clone());
6030 let first_hop = first_hop(src);
6031 let amt = seed as u64 % 1_000_000;
6032 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
6034 route_endpoints.push((first_hop, params, amt));
6035 continue 'load_endpoints;
6040 // ...and seed the scorer with success and failure data...
6041 for route in routes {
6042 let amount = route.get_total_amount();
6043 if amount < 250_000 {
6044 for path in route.paths {
6045 scorer.payment_path_successful(&path);
6047 } else if amount > 750_000 {
6048 for path in route.paths {
6049 let short_channel_id = path.hops[path.hops.len() / 2].short_channel_id;
6050 scorer.payment_path_failed(&path, short_channel_id);
6055 // Because we've changed channel scores, its possible we'll take different routes to the
6056 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
6057 // requires a too-high CLTV delta.
6058 route_endpoints.retain(|(first_hop, params, amt)| {
6059 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
6061 route_endpoints.truncate(100);
6062 assert_eq!(route_endpoints.len(), 100);
6064 // ...then benchmark finding paths between the nodes we learned.
6067 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
6068 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());