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::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: &[&RouteHop], short_channel_id: u64) {
141 self.scorer.payment_path_failed(path, short_channel_id)
144 fn payment_path_successful(&mut self, path: &[&RouteHop]) {
145 self.scorer.payment_path_successful(path)
148 fn probe_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
149 self.scorer.probe_failed(path, short_channel_id)
152 fn probe_successful(&mut self, path: &[&RouteHop]) {
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: &[RouteHop], payer_node_id: PublicKey) {
174 if path.is_empty() { return };
175 // total_inflight_map needs to be direction-sensitive when keeping track of the HTLC value
176 // that is held up. However, the `hops` array, which is a path returned by `find_route` in
177 // the router excludes the payer node. In the following lines, the payer's information is
178 // hardcoded with an inflight value of 0 so that we can correctly represent the first hop
179 // in our sliding window of two.
180 let reversed_hops_with_payer = path.iter().rev().skip(1)
181 .map(|hop| hop.pubkey)
182 .chain(core::iter::once(payer_node_id));
183 let mut cumulative_msat = 0;
185 // Taking the reversed vector from above, we zip it with just the reversed hops list to
186 // work "backwards" of the given path, since the last hop's `fee_msat` actually represents
187 // the total amount sent.
188 for (next_hop, prev_hop) in path.iter().rev().zip(reversed_hops_with_payer) {
189 cumulative_msat += next_hop.fee_msat;
191 .entry((next_hop.short_channel_id, NodeId::from_pubkey(&prev_hop) < NodeId::from_pubkey(&next_hop.pubkey)))
192 .and_modify(|used_liquidity_msat| *used_liquidity_msat += cumulative_msat)
193 .or_insert(cumulative_msat);
197 /// Returns liquidity in msat given the public key of the HTLC source, target, and short channel
199 pub fn used_liquidity_msat(&self, source: &NodeId, target: &NodeId, channel_scid: u64) -> Option<u64> {
200 self.0.get(&(channel_scid, source < target)).map(|v| *v)
204 impl Writeable for InFlightHtlcs {
205 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.0.write(writer) }
208 impl Readable for InFlightHtlcs {
209 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
210 let infight_map: HashMap<(u64, bool), u64> = Readable::read(reader)?;
211 Ok(Self(infight_map))
215 /// A hop in a route, and additional metadata about it. "Hop" is defined as a node and the channel
216 /// that leads to it.
217 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
218 pub struct RouteHop {
219 /// The node_id of the node at this hop.
220 pub pubkey: PublicKey,
221 /// The node_announcement features of the node at this hop. For the last hop, these may be
222 /// amended to match the features present in the invoice this node generated.
223 pub node_features: NodeFeatures,
224 /// The channel that should be used from the previous hop to reach this node.
225 pub short_channel_id: u64,
226 /// The channel_announcement features of the channel that should be used from the previous hop
227 /// to reach this node.
228 pub channel_features: ChannelFeatures,
229 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
230 /// For the last hop, this should be the full value of this path's part of the payment.
232 /// The CLTV delta added for this hop. For the last hop, this is the CLTV delta expected at the
234 pub cltv_expiry_delta: u32,
237 impl_writeable_tlv_based!(RouteHop, {
238 (0, pubkey, required),
239 (2, node_features, required),
240 (4, short_channel_id, required),
241 (6, channel_features, required),
242 (8, fee_msat, required),
243 (10, cltv_expiry_delta, required),
246 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
247 /// it can take multiple paths. Each path is composed of one or more hops through the network.
248 #[derive(Clone, Hash, PartialEq, Eq)]
250 /// The list of paths taken for a single (potentially-)multi-part payment. The pubkey of the
251 /// last [`RouteHop`] in each path must be the same. Each entry represents a list of hops, where
252 /// the last hop is the destination. Thus, this must always be at least length one. While the
253 /// maximum length of any given path is variable, keeping the length of any path less or equal to
254 /// 19 should currently ensure it is viable.
255 pub paths: Vec<Vec<RouteHop>>,
256 /// The `payment_params` parameter passed to [`find_route`].
257 /// This is used by `ChannelManager` to track information which may be required for retries,
258 /// provided back to you via [`Event::PaymentPathFailed`].
260 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
261 pub payment_params: Option<PaymentParameters>,
264 pub(crate) trait RoutePath {
265 /// Gets the fees for a given path, excluding any excess paid to the recipient.
266 fn get_path_fees(&self) -> u64;
268 impl RoutePath for Vec<RouteHop> {
269 fn get_path_fees(&self) -> u64 {
270 // Do not count last hop of each path since that's the full value of the payment
271 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
272 .iter().map(|hop| &hop.fee_msat)
278 /// Returns the total amount of fees paid on this [`Route`].
280 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
281 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
282 pub fn get_total_fees(&self) -> u64 {
283 self.paths.iter().map(|path| path.get_path_fees()).sum()
286 /// Returns the total amount paid on this [`Route`], excluding the fees. Might be more than
287 /// requested if we had to reach htlc_minimum_msat.
288 pub fn get_total_amount(&self) -> u64 {
289 return self.paths.iter()
290 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
295 const SERIALIZATION_VERSION: u8 = 1;
296 const MIN_SERIALIZATION_VERSION: u8 = 1;
298 impl Writeable for Route {
299 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
300 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
301 (self.paths.len() as u64).write(writer)?;
302 for hops in self.paths.iter() {
303 (hops.len() as u8).write(writer)?;
304 for hop in hops.iter() {
308 write_tlv_fields!(writer, {
309 (1, self.payment_params, option),
315 impl Readable for Route {
316 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
317 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
318 let path_count: u64 = Readable::read(reader)?;
319 if path_count == 0 { return Err(DecodeError::InvalidValue); }
320 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
321 let mut min_final_cltv_expiry_delta = u32::max_value();
322 for _ in 0..path_count {
323 let hop_count: u8 = Readable::read(reader)?;
324 let mut hops: Vec<RouteHop> = Vec::with_capacity(hop_count as usize);
325 for _ in 0..hop_count {
326 hops.push(Readable::read(reader)?);
328 if hops.is_empty() { return Err(DecodeError::InvalidValue); }
329 min_final_cltv_expiry_delta =
330 cmp::min(min_final_cltv_expiry_delta, hops.last().unwrap().cltv_expiry_delta);
333 let mut payment_params = None;
334 read_tlv_fields!(reader, {
335 (1, payment_params, (option: ReadableArgs, min_final_cltv_expiry_delta)),
337 Ok(Route { paths, payment_params })
341 /// Parameters needed to find a [`Route`].
343 /// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
344 /// [`Event::PaymentPathFailed`].
346 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
347 #[derive(Clone, Debug, PartialEq, Eq)]
348 pub struct RouteParameters {
349 /// The parameters of the failed payment path.
350 pub payment_params: PaymentParameters,
352 /// The amount in msats sent on the failed payment path.
353 pub final_value_msat: u64,
356 impl Writeable for RouteParameters {
357 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
358 write_tlv_fields!(writer, {
359 (0, self.payment_params, required),
360 (2, self.final_value_msat, required),
361 // LDK versions prior to 0.0.114 had the `final_cltv_expiry_delta` parameter in
362 // `RouteParameters` directly. For compatibility, we write it here.
363 (4, self.payment_params.final_cltv_expiry_delta, required),
369 impl Readable for RouteParameters {
370 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
371 _init_and_read_tlv_fields!(reader, {
372 (0, payment_params, (required: ReadableArgs, 0)),
373 (2, final_value_msat, required),
374 (4, final_cltv_expiry_delta, required),
376 let mut payment_params: PaymentParameters = payment_params.0.unwrap();
377 if payment_params.final_cltv_expiry_delta == 0 {
378 payment_params.final_cltv_expiry_delta = final_cltv_expiry_delta.0.unwrap();
382 final_value_msat: final_value_msat.0.unwrap(),
387 /// Maximum total CTLV difference we allow for a full payment path.
388 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
390 /// Maximum number of paths we allow an (MPP) payment to have.
391 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
392 // limits, but for now more than 10 paths likely carries too much one-path failure.
393 pub const DEFAULT_MAX_PATH_COUNT: u8 = 10;
395 // The median hop CLTV expiry delta currently seen in the network.
396 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
398 // During routing, we only consider paths shorter than our maximum length estimate.
399 // In the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
400 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
401 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
403 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
404 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
405 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
406 // (payment_secret and total_msat) = 93 bytes for the final hop.
407 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
408 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
409 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
411 /// The recipient of a payment.
412 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
413 pub struct PaymentParameters {
414 /// The node id of the payee.
415 pub payee_pubkey: PublicKey,
417 /// Features supported by the payee.
419 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
420 /// does not contain any features.
422 /// [`for_keysend`]: Self::for_keysend
423 pub features: Option<InvoiceFeatures>,
425 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
426 pub route_hints: Hints,
428 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
429 pub expiry_time: Option<u64>,
431 /// The maximum total CLTV delta we accept for the route.
432 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
433 pub max_total_cltv_expiry_delta: u32,
435 /// The maximum number of paths that may be used by (MPP) payments.
436 /// Defaults to [`DEFAULT_MAX_PATH_COUNT`].
437 pub max_path_count: u8,
439 /// Selects the maximum share of a channel's total capacity which will be sent over a channel,
440 /// as a power of 1/2. A higher value prefers to send the payment using more MPP parts whereas
441 /// a lower value prefers to send larger MPP parts, potentially saturating channels and
442 /// increasing failure probability for those paths.
444 /// Note that this restriction will be relaxed during pathfinding after paths which meet this
445 /// restriction have been found. While paths which meet this criteria will be searched for, it
446 /// is ultimately up to the scorer to select them over other paths.
448 /// A value of 0 will allow payments up to and including a channel's total announced usable
449 /// capacity, a value of one will only use up to half its capacity, two 1/4, etc.
452 pub max_channel_saturation_power_of_half: u8,
454 /// A list of SCIDs which this payment was previously attempted over and which caused the
455 /// payment to fail. Future attempts for the same payment shouldn't be relayed through any of
457 pub previously_failed_channels: Vec<u64>,
459 /// The minimum CLTV delta at the end of the route. This value must not be zero.
460 pub final_cltv_expiry_delta: u32,
463 impl Writeable for PaymentParameters {
464 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
465 let mut clear_hints = &vec![];
466 let mut blinded_hints = &vec![];
467 match &self.route_hints {
468 Hints::Clear(hints) => clear_hints = hints,
469 Hints::Blinded(hints) => blinded_hints = hints,
471 write_tlv_fields!(writer, {
472 (0, self.payee_pubkey, required),
473 (1, self.max_total_cltv_expiry_delta, required),
474 (2, self.features, option),
475 (3, self.max_path_count, required),
476 (4, *clear_hints, vec_type),
477 (5, self.max_channel_saturation_power_of_half, required),
478 (6, self.expiry_time, option),
479 (7, self.previously_failed_channels, vec_type),
480 (8, *blinded_hints, optional_vec),
481 (9, self.final_cltv_expiry_delta, required),
487 impl ReadableArgs<u32> for PaymentParameters {
488 fn read<R: io::Read>(reader: &mut R, default_final_cltv_expiry_delta: u32) -> Result<Self, DecodeError> {
489 _init_and_read_tlv_fields!(reader, {
490 (0, payee_pubkey, required),
491 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
492 (2, features, option),
493 (3, max_path_count, (default_value, DEFAULT_MAX_PATH_COUNT)),
494 (4, route_hints, vec_type),
495 (5, max_channel_saturation_power_of_half, (default_value, 2)),
496 (6, expiry_time, option),
497 (7, previously_failed_channels, vec_type),
498 (8, blinded_route_hints, optional_vec),
499 (9, final_cltv_expiry_delta, (default_value, default_final_cltv_expiry_delta)),
501 let clear_route_hints = route_hints.unwrap_or(vec![]);
502 let blinded_route_hints = blinded_route_hints.unwrap_or(vec![]);
503 let route_hints = if blinded_route_hints.len() != 0 {
504 if clear_route_hints.len() != 0 { return Err(DecodeError::InvalidValue) }
505 Hints::Blinded(blinded_route_hints)
507 Hints::Clear(clear_route_hints)
510 payee_pubkey: _init_tlv_based_struct_field!(payee_pubkey, required),
511 max_total_cltv_expiry_delta: _init_tlv_based_struct_field!(max_total_cltv_expiry_delta, (default_value, unused)),
513 max_path_count: _init_tlv_based_struct_field!(max_path_count, (default_value, unused)),
515 max_channel_saturation_power_of_half: _init_tlv_based_struct_field!(max_channel_saturation_power_of_half, (default_value, unused)),
517 previously_failed_channels: previously_failed_channels.unwrap_or(Vec::new()),
518 final_cltv_expiry_delta: _init_tlv_based_struct_field!(final_cltv_expiry_delta, (default_value, unused)),
524 impl PaymentParameters {
525 /// Creates a payee with the node id of the given `pubkey`.
527 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
529 pub fn from_node_id(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
533 route_hints: Hints::Clear(vec![]),
535 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
536 max_path_count: DEFAULT_MAX_PATH_COUNT,
537 max_channel_saturation_power_of_half: 2,
538 previously_failed_channels: Vec::new(),
539 final_cltv_expiry_delta,
543 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
545 /// The `final_cltv_expiry_delta` should match the expected final CLTV delta the recipient has
547 pub fn for_keysend(payee_pubkey: PublicKey, final_cltv_expiry_delta: u32) -> Self {
548 Self::from_node_id(payee_pubkey, final_cltv_expiry_delta).with_features(InvoiceFeatures::for_keysend())
551 /// Includes the payee's features.
553 /// This is not exported to bindings users since bindings don't support move semantics
554 pub fn with_features(self, features: InvoiceFeatures) -> Self {
555 Self { features: Some(features), ..self }
558 /// Includes hints for routing to the payee.
560 /// This is not exported to bindings users since bindings don't support move semantics
561 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
562 Self { route_hints: Hints::Clear(route_hints), ..self }
565 /// Includes a payment expiration in seconds relative to the UNIX epoch.
567 /// This is not exported to bindings users since bindings don't support move semantics
568 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
569 Self { expiry_time: Some(expiry_time), ..self }
572 /// Includes a limit for the total CLTV expiry delta which is considered during routing
574 /// This is not exported to bindings users since bindings don't support move semantics
575 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
576 Self { max_total_cltv_expiry_delta, ..self }
579 /// Includes a limit for the maximum number of payment paths that may be used.
581 /// This is not exported to bindings users since bindings don't support move semantics
582 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
583 Self { max_path_count, ..self }
586 /// Includes a limit for the maximum number of payment paths that may be used.
588 /// This is not exported to bindings users since bindings don't support move semantics
589 pub fn with_max_channel_saturation_power_of_half(self, max_channel_saturation_power_of_half: u8) -> Self {
590 Self { max_channel_saturation_power_of_half, ..self }
594 /// Routing hints for the tail of the route.
595 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
597 /// The recipient provided blinded paths and payinfo to reach them. The blinded paths themselves
598 /// will be included in the final [`Route`].
599 Blinded(Vec<(BlindedPayInfo, BlindedPath)>),
600 /// The recipient included these route hints in their BOLT11 invoice.
601 Clear(Vec<RouteHint>),
604 /// A list of hops along a payment path terminating with a channel to the recipient.
605 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
606 pub struct RouteHint(pub Vec<RouteHintHop>);
608 impl Writeable for RouteHint {
609 fn write<W: crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
610 (self.0.len() as u64).write(writer)?;
611 for hop in self.0.iter() {
618 impl Readable for RouteHint {
619 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
620 let hop_count: u64 = Readable::read(reader)?;
621 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
622 for _ in 0..hop_count {
623 hops.push(Readable::read(reader)?);
629 /// A channel descriptor for a hop along a payment path.
630 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
631 pub struct RouteHintHop {
632 /// The node_id of the non-target end of the route
633 pub src_node_id: PublicKey,
634 /// The short_channel_id of this channel
635 pub short_channel_id: u64,
636 /// The fees which must be paid to use this channel
637 pub fees: RoutingFees,
638 /// The difference in CLTV values between this node and the next node.
639 pub cltv_expiry_delta: u16,
640 /// The minimum value, in msat, which must be relayed to the next hop.
641 pub htlc_minimum_msat: Option<u64>,
642 /// The maximum value in msat available for routing with a single HTLC.
643 pub htlc_maximum_msat: Option<u64>,
646 impl_writeable_tlv_based!(RouteHintHop, {
647 (0, src_node_id, required),
648 (1, htlc_minimum_msat, option),
649 (2, short_channel_id, required),
650 (3, htlc_maximum_msat, option),
652 (6, cltv_expiry_delta, required),
655 #[derive(Eq, PartialEq)]
656 struct RouteGraphNode {
658 lowest_fee_to_node: u64,
659 total_cltv_delta: u32,
660 // The maximum value a yet-to-be-constructed payment path might flow through this node.
661 // This value is upper-bounded by us by:
662 // - how much is needed for a path being constructed
663 // - how much value can channels following this node (up to the destination) can contribute,
664 // considering their capacity and fees
665 value_contribution_msat: u64,
666 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
667 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
668 path_htlc_minimum_msat: u64,
669 /// All penalties incurred from this hop on the way to the destination, as calculated using
671 path_penalty_msat: u64,
672 /// The number of hops walked up to this node.
673 path_length_to_node: u8,
676 impl cmp::Ord for RouteGraphNode {
677 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
678 let other_score = cmp::max(other.lowest_fee_to_node, other.path_htlc_minimum_msat)
679 .saturating_add(other.path_penalty_msat);
680 let self_score = cmp::max(self.lowest_fee_to_node, self.path_htlc_minimum_msat)
681 .saturating_add(self.path_penalty_msat);
682 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
686 impl cmp::PartialOrd for RouteGraphNode {
687 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
688 Some(self.cmp(other))
692 /// A wrapper around the various hop representations.
694 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
695 #[derive(Clone, Debug)]
696 enum CandidateRouteHop<'a> {
697 /// A hop from the payer, where the outbound liquidity is known.
699 details: &'a ChannelDetails,
701 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
703 info: DirectedChannelInfo<'a>,
704 short_channel_id: u64,
706 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
708 hint: &'a RouteHintHop,
712 impl<'a> CandidateRouteHop<'a> {
713 fn short_channel_id(&self) -> u64 {
715 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
716 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
717 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
721 // NOTE: This may alloc memory so avoid calling it in a hot code path.
722 fn features(&self) -> ChannelFeatures {
724 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
725 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
726 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
730 fn cltv_expiry_delta(&self) -> u32 {
732 CandidateRouteHop::FirstHop { .. } => 0,
733 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
734 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
738 fn htlc_minimum_msat(&self) -> u64 {
740 CandidateRouteHop::FirstHop { .. } => 0,
741 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
742 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
746 fn fees(&self) -> RoutingFees {
748 CandidateRouteHop::FirstHop { .. } => RoutingFees {
749 base_msat: 0, proportional_millionths: 0,
751 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
752 CandidateRouteHop::PrivateHop { hint } => hint.fees,
756 fn effective_capacity(&self) -> EffectiveCapacity {
758 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
759 liquidity_msat: details.next_outbound_htlc_limit_msat,
761 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
762 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
768 fn max_htlc_from_capacity(capacity: EffectiveCapacity, max_channel_saturation_power_of_half: u8) -> u64 {
769 let saturation_shift: u32 = max_channel_saturation_power_of_half as u32;
771 EffectiveCapacity::ExactLiquidity { liquidity_msat } => liquidity_msat,
772 EffectiveCapacity::Infinite => u64::max_value(),
773 EffectiveCapacity::Unknown => EffectiveCapacity::Unknown.as_msat(),
774 EffectiveCapacity::MaximumHTLC { amount_msat } =>
775 amount_msat.checked_shr(saturation_shift).unwrap_or(0),
776 EffectiveCapacity::Total { capacity_msat, htlc_maximum_msat } =>
777 cmp::min(capacity_msat.checked_shr(saturation_shift).unwrap_or(0), htlc_maximum_msat),
781 fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
782 -> bool where I1::Item: PartialEq<I2::Item> {
784 let a = iter_a.next();
785 let b = iter_b.next();
786 if a.is_none() && b.is_none() { return true; }
787 if a.is_none() || b.is_none() { return false; }
788 if a.unwrap().ne(&b.unwrap()) { return false; }
792 /// It's useful to keep track of the hops associated with the fees required to use them,
793 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
794 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
795 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
797 struct PathBuildingHop<'a> {
798 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
799 // is a larger refactor and will require careful performance analysis.
801 candidate: CandidateRouteHop<'a>,
804 /// All the fees paid *after* this channel on the way to the destination
805 next_hops_fee_msat: u64,
806 /// Fee paid for the use of the current channel (see candidate.fees()).
807 /// The value will be actually deducted from the counterparty balance on the previous link.
808 hop_use_fee_msat: u64,
809 /// Used to compare channels when choosing the for routing.
810 /// Includes paying for the use of a hop and the following hops, as well as
811 /// an estimated cost of reaching this hop.
812 /// Might get stale when fees are recomputed. Primarily for internal use.
814 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
815 /// walk and may be invalid thereafter.
816 path_htlc_minimum_msat: u64,
817 /// All penalties incurred from this channel on the way to the destination, as calculated using
819 path_penalty_msat: u64,
820 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
821 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
822 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
823 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
824 /// avoid processing them again.
826 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
827 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
828 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
829 // value_contribution_msat, which requires tracking it here. See comments below where it is
830 // used for more info.
831 value_contribution_msat: u64,
834 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
835 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
836 let mut debug_struct = f.debug_struct("PathBuildingHop");
838 .field("node_id", &self.node_id)
839 .field("short_channel_id", &self.candidate.short_channel_id())
840 .field("total_fee_msat", &self.total_fee_msat)
841 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
842 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
843 .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)))
844 .field("path_penalty_msat", &self.path_penalty_msat)
845 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
846 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
847 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
848 let debug_struct = debug_struct
849 .field("value_contribution_msat", &self.value_contribution_msat);
850 debug_struct.finish()
854 // Instantiated with a list of hops with correct data in them collected during path finding,
855 // an instance of this struct should be further modified only via given methods.
857 struct PaymentPath<'a> {
858 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
861 impl<'a> PaymentPath<'a> {
862 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
863 fn get_value_msat(&self) -> u64 {
864 self.hops.last().unwrap().0.fee_msat
867 fn get_path_penalty_msat(&self) -> u64 {
868 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
871 fn get_total_fee_paid_msat(&self) -> u64 {
872 if self.hops.len() < 1 {
876 // Can't use next_hops_fee_msat because it gets outdated.
877 for (i, (hop, _)) in self.hops.iter().enumerate() {
878 if i != self.hops.len() - 1 {
879 result += hop.fee_msat;
885 fn get_cost_msat(&self) -> u64 {
886 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
889 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
890 // to change fees may result in an inconsistency.
892 // Sometimes we call this function right after constructing a path which is inconsistent in
893 // that it the value being transferred has decreased while we were doing path finding, leading
894 // to the fees being paid not lining up with the actual limits.
896 // Note that this function is not aware of the available_liquidity limit, and thus does not
897 // support increasing the value being transferred beyond what was selected during the initial
899 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
900 let mut total_fee_paid_msat = 0 as u64;
901 for i in (0..self.hops.len()).rev() {
902 let last_hop = i == self.hops.len() - 1;
904 // For non-last-hop, this value will represent the fees paid on the current hop. It
905 // will consist of the fees for the use of the next hop, and extra fees to match
906 // htlc_minimum_msat of the current channel. Last hop is handled separately.
907 let mut cur_hop_fees_msat = 0;
909 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
912 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
913 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
914 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
915 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
916 // set it too high just to maliciously take more fees by exploiting this
917 // match htlc_minimum_msat logic.
918 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
919 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
920 // Note that there is a risk that *previous hops* (those closer to us, as we go
921 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
923 // This might make us end up with a broken route, although this should be super-rare
924 // in practice, both because of how healthy channels look like, and how we pick
925 // channels in add_entry.
926 // Also, this can't be exploited more heavily than *announce a free path and fail
928 cur_hop_transferred_amount_msat += extra_fees_msat;
929 total_fee_paid_msat += extra_fees_msat;
930 cur_hop_fees_msat += extra_fees_msat;
934 // Final hop is a special case: it usually has just value_msat (by design), but also
935 // it still could overpay for the htlc_minimum_msat.
936 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
938 // Propagate updated fees for the use of the channels to one hop back, where they
939 // will be actually paid (fee_msat). The last hop is handled above separately.
940 cur_hop.fee_msat = cur_hop_fees_msat;
943 // Fee for the use of the current hop which will be deducted on the previous hop.
944 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
945 // this channel is free for us.
947 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
948 cur_hop.hop_use_fee_msat = new_fee;
949 total_fee_paid_msat += new_fee;
951 // It should not be possible because this function is called only to reduce the
952 // value. In that case, compute_fee was already called with the same fees for
953 // larger amount and there was no overflow.
962 /// Calculate the fees required to route the given amount over a channel with the given fees.
963 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
964 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
965 .and_then(|part| (channel_fees.base_msat as u64).checked_add(part / 1_000_000))
969 /// Calculate the fees required to route the given amount over a channel with the given fees,
970 /// saturating to [`u64::max_value`].
971 fn compute_fees_saturating(amount_msat: u64, channel_fees: RoutingFees) -> u64 {
972 amount_msat.checked_mul(channel_fees.proportional_millionths as u64)
973 .map(|prop| prop / 1_000_000).unwrap_or(u64::max_value())
974 .saturating_add(channel_fees.base_msat as u64)
977 /// The default `features` we assume for a node in a route, when no `features` are known about that
980 /// Default features are:
981 /// * variable_length_onion_optional
982 fn default_node_features() -> NodeFeatures {
983 let mut features = NodeFeatures::empty();
984 features.set_variable_length_onion_optional();
988 /// Finds a route from us (payer) to the given target node (payee).
990 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
991 /// Without this, MPP will only be used if the payee's features are available in the network graph.
993 /// Private routing paths between a public node and the target may be included in `params.payee`.
995 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
996 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
997 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
999 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
1000 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
1001 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
1005 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
1006 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
1011 /// Panics if first_hops contains channels without short_channel_ids;
1012 /// [`ChannelManager::list_usable_channels`] will never include such channels.
1014 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
1015 /// [`Event::PaymentPathFailed`]: crate::events::Event::PaymentPathFailed
1016 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
1017 pub fn find_route<L: Deref, GL: Deref, S: Score>(
1018 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
1019 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
1020 scorer: &S, random_seed_bytes: &[u8; 32]
1021 ) -> Result<Route, LightningError>
1022 where L::Target: Logger, GL::Target: Logger {
1023 let graph_lock = network_graph.read_only();
1024 let final_cltv_expiry_delta = route_params.payment_params.final_cltv_expiry_delta;
1025 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
1026 route_params.final_value_msat, final_cltv_expiry_delta, logger, scorer,
1027 random_seed_bytes)?;
1028 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1032 pub(crate) fn get_route<L: Deref, S: Score>(
1033 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
1034 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
1035 logger: L, scorer: &S, _random_seed_bytes: &[u8; 32]
1036 ) -> Result<Route, LightningError>
1037 where L::Target: Logger {
1038 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
1039 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
1041 if payee_node_id == our_node_id {
1042 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
1045 if final_value_msat > MAX_VALUE_MSAT {
1046 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
1049 if final_value_msat == 0 {
1050 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
1053 match &payment_params.route_hints {
1054 Hints::Clear(hints) => {
1055 for route in hints.iter() {
1056 for hop in &route.0 {
1057 if hop.src_node_id == payment_params.payee_pubkey {
1058 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
1063 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1066 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
1067 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});
1070 // TODO: Remove the explicit final_cltv_expiry_delta parameter
1071 debug_assert_eq!(final_cltv_expiry_delta, payment_params.final_cltv_expiry_delta);
1073 // The general routing idea is the following:
1074 // 1. Fill first/last hops communicated by the caller.
1075 // 2. Attempt to construct a path from payer to payee for transferring
1076 // any ~sufficient (described later) value.
1077 // If succeed, remember which channels were used and how much liquidity they have available,
1078 // so that future paths don't rely on the same liquidity.
1079 // 3. Proceed to the next step if:
1080 // - we hit the recommended target value;
1081 // - OR if we could not construct a new path. Any next attempt will fail too.
1082 // Otherwise, repeat step 2.
1083 // 4. See if we managed to collect paths which aggregately are able to transfer target value
1084 // (not recommended value).
1085 // 5. If yes, proceed. If not, fail routing.
1086 // 6. Select the paths which have the lowest cost (fee plus scorer penalty) per amount
1087 // transferred up to the transfer target value.
1088 // 7. Reduce the value of the last path until we are sending only the target value.
1089 // 8. If our maximum channel saturation limit caused us to pick two identical paths, combine
1090 // them so that we're not sending two HTLCs along the same path.
1092 // As for the actual search algorithm, we do a payee-to-payer Dijkstra's sorting by each node's
1093 // distance from the payee
1095 // We are not a faithful Dijkstra's implementation because we can change values which impact
1096 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
1097 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
1098 // the value we are currently attempting to send over a path, we simply reduce the value being
1099 // sent along the path for any hops after that channel. This may imply that later fees (which
1100 // we've already tabulated) are lower because a smaller value is passing through the channels
1101 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
1102 // channels which were selected earlier (and which may still be used for other paths without a
1103 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
1106 // One potentially problematic case for this algorithm would be if there are many
1107 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
1108 // graph walking), we may never find a path which is not liquidity-limited and has lower
1109 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
1110 // Because we only consider paths with at least 5% of the total value being sent, the damage
1111 // from such a case should be limited, however this could be further reduced in the future by
1112 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
1113 // limits for the purposes of fee calculation.
1115 // Alternatively, we could store more detailed path information in the heap (targets, below)
1116 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
1117 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
1118 // and practically (as we would need to store dynamically-allocated path information in heap
1119 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
1120 // results of such an algorithm would likely be biased towards lower-value paths.
1122 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
1123 // outside of our current search value, running a path search more times to gather candidate
1124 // paths at different values. While this may be acceptable, further path searches may increase
1125 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
1126 // graph for candidate paths, calculating the maximum value which can realistically be sent at
1127 // the same time, remaining generic across different payment values.
1129 let network_channels = network_graph.channels();
1130 let network_nodes = network_graph.nodes();
1132 if payment_params.max_path_count == 0 {
1133 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
1136 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
1137 // it. If the payee supports it they're supposed to include it in the invoice, so that should
1139 let allow_mpp = if payment_params.max_path_count == 1 {
1141 } else if let Some(features) = &payment_params.features {
1142 features.supports_basic_mpp()
1143 } else if let Some(node) = network_nodes.get(&payee_node_id) {
1144 if let Some(node_info) = node.announcement_info.as_ref() {
1145 node_info.features.supports_basic_mpp()
1149 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
1150 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
1151 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
1154 // Prepare the data we'll use for payee-to-payer search by
1155 // inserting first hops suggested by the caller as targets.
1156 // Our search will then attempt to reach them while traversing from the payee node.
1157 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
1158 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
1159 if let Some(hops) = first_hops {
1161 if chan.get_outbound_payment_scid().is_none() {
1162 panic!("first_hops should be filled in with usable channels, not pending ones");
1164 if chan.counterparty.node_id == *our_node_pubkey {
1165 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
1168 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
1169 .or_insert(Vec::new())
1172 if first_hop_targets.is_empty() {
1173 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
1177 // The main heap containing all candidate next-hops sorted by their score (max(fee,
1178 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
1179 // adding duplicate entries when we find a better path to a given node.
1180 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
1182 // Map from node_id to information about the best current path to that node, including feerate
1184 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
1186 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
1187 // indicating that we may wish to try again with a higher value, potentially paying to meet an
1188 // htlc_minimum with extra fees while still finding a cheaper path.
1189 let mut hit_minimum_limit;
1191 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
1192 // We start with a path_value of the exact amount we want, and if that generates a route we may
1193 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
1194 // amount we want in total across paths, selecting the best subset at the end.
1195 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
1196 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
1197 let mut path_value_msat = final_value_msat;
1199 // Routing Fragmentation Mitigation heuristic:
1201 // Routing fragmentation across many payment paths increases the overall routing
1202 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
1203 // Taking too many smaller paths also increases the chance of payment failure.
1204 // Thus to avoid this effect, we require from our collected links to provide
1205 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
1206 // This requirement is currently set to be 1/max_path_count of the payment
1207 // value to ensure we only ever return routes that do not violate this limit.
1208 let minimal_value_contribution_msat: u64 = if allow_mpp {
1209 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
1214 // When we start collecting routes we enforce the max_channel_saturation_power_of_half
1215 // requirement strictly. After we've collected enough (or if we fail to find new routes) we
1216 // drop the requirement by setting this to 0.
1217 let mut channel_saturation_pow_half = payment_params.max_channel_saturation_power_of_half;
1219 // Keep track of how much liquidity has been used in selected channels. Used to determine
1220 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
1221 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
1222 // liquidity used in one direction will not offset any used in the opposite direction.
1223 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
1224 HashMap::with_capacity(network_nodes.len());
1226 // Keeping track of how much value we already collected across other paths. Helps to decide
1227 // when we want to stop looking for new paths.
1228 let mut already_collected_value_msat = 0;
1230 for (_, channels) in first_hop_targets.iter_mut() {
1231 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
1232 // most like to use.
1234 // First, if channels are below `recommended_value_msat`, sort them in descending order,
1235 // preferring larger channels to avoid splitting the payment into more MPP parts than is
1238 // Second, because simply always sorting in descending order would always use our largest
1239 // available outbound capacity, needlessly fragmenting our available channel capacities,
1240 // sort channels above `recommended_value_msat` in ascending order, preferring channels
1241 // which have enough, but not too much, capacity for the payment.
1242 channels.sort_unstable_by(|chan_a, chan_b| {
1243 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
1244 // Sort in descending order
1245 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
1247 // Sort in ascending order
1248 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
1253 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
1255 macro_rules! add_entry {
1256 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
1257 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
1258 // since that value has to be transferred over this channel.
1259 // Returns whether this channel caused an update to `targets`.
1260 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
1261 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
1262 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
1263 // We "return" whether we updated the path at the end, via this:
1264 let mut did_add_update_path_to_src_node = false;
1265 // Channels to self should not be used. This is more of belt-and-suspenders, because in
1266 // practice these cases should be caught earlier:
1267 // - for regular channels at channel announcement (TODO)
1268 // - for first and last hops early in get_route
1269 if $src_node_id != $dest_node_id {
1270 let short_channel_id = $candidate.short_channel_id();
1271 let effective_capacity = $candidate.effective_capacity();
1272 let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
1274 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
1275 // It may be misleading because we might later choose to reduce the value transferred
1276 // over these channels, and the channel which was insufficient might become sufficient.
1277 // Worst case: we drop a good channel here because it can't cover the high following
1278 // fees caused by one expensive channel, but then this channel could have been used
1279 // if the amount being transferred over this path is lower.
1280 // We do this for now, but this is a subject for removal.
1281 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
1282 let used_liquidity_msat = used_channel_liquidities
1283 .get(&(short_channel_id, $src_node_id < $dest_node_id))
1284 .map_or(0, |used_liquidity_msat| {
1285 available_value_contribution_msat = available_value_contribution_msat
1286 .saturating_sub(*used_liquidity_msat);
1287 *used_liquidity_msat
1290 // Verify the liquidity offered by this channel complies to the minimal contribution.
1291 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
1292 // Do not consider candidate hops that would exceed the maximum path length.
1293 let path_length_to_node = $next_hops_path_length + 1;
1294 let exceeds_max_path_length = path_length_to_node > MAX_PATH_LENGTH_ESTIMATE;
1296 // Do not consider candidates that exceed the maximum total cltv expiry limit.
1297 // In order to already account for some of the privacy enhancing random CLTV
1298 // expiry delta offset we add on top later, we subtract a rough estimate
1299 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
1300 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
1301 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
1302 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
1303 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
1304 .saturating_add($candidate.cltv_expiry_delta());
1305 let exceeds_cltv_delta_limit = hop_total_cltv_delta > max_total_cltv_expiry_delta;
1307 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
1308 // Includes paying fees for the use of the following channels.
1309 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
1310 Some(result) => result,
1311 // Can't overflow due to how the values were computed right above.
1312 None => unreachable!(),
1314 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1315 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
1316 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
1318 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
1319 let may_overpay_to_meet_path_minimum_msat =
1320 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
1321 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
1322 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
1323 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
1325 let payment_failed_on_this_channel =
1326 payment_params.previously_failed_channels.contains(&short_channel_id);
1328 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
1329 // bother considering this channel. If retrying with recommended_value_msat may
1330 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
1331 // around again with a higher amount.
1332 if !contributes_sufficient_value || exceeds_max_path_length ||
1333 exceeds_cltv_delta_limit || payment_failed_on_this_channel {
1334 // Path isn't useful, ignore it and move on.
1335 } else if may_overpay_to_meet_path_minimum_msat {
1336 hit_minimum_limit = true;
1337 } else if over_path_minimum_msat {
1338 // Note that low contribution here (limited by available_liquidity_msat)
1339 // might violate htlc_minimum_msat on the hops which are next along the
1340 // payment path (upstream to the payee). To avoid that, we recompute
1341 // path fees knowing the final path contribution after constructing it.
1342 let path_htlc_minimum_msat = cmp::max(
1343 compute_fees_saturating($next_hops_path_htlc_minimum_msat, $candidate.fees())
1344 .saturating_add($next_hops_path_htlc_minimum_msat),
1345 $candidate.htlc_minimum_msat());
1346 let hm_entry = dist.entry($src_node_id);
1347 let old_entry = hm_entry.or_insert_with(|| {
1348 // If there was previously no known way to access the source node
1349 // (recall it goes payee-to-payer) of short_channel_id, first add a
1350 // semi-dummy record just to compute the fees to reach the source node.
1351 // This will affect our decision on selecting short_channel_id
1352 // as a way to reach the $dest_node_id.
1354 node_id: $dest_node_id.clone(),
1355 candidate: $candidate.clone(),
1357 next_hops_fee_msat: u64::max_value(),
1358 hop_use_fee_msat: u64::max_value(),
1359 total_fee_msat: u64::max_value(),
1360 path_htlc_minimum_msat,
1361 path_penalty_msat: u64::max_value(),
1362 was_processed: false,
1363 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1364 value_contribution_msat,
1368 #[allow(unused_mut)] // We only use the mut in cfg(test)
1369 let mut should_process = !old_entry.was_processed;
1370 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1372 // In test/fuzzing builds, we do extra checks to make sure the skipping
1373 // of already-seen nodes only happens in cases we expect (see below).
1374 if !should_process { should_process = true; }
1378 let mut hop_use_fee_msat = 0;
1379 let mut total_fee_msat: u64 = $next_hops_fee_msat;
1381 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1382 // will have the same effective-fee
1383 if $src_node_id != our_node_id {
1384 // Note that `u64::max_value` means we'll always fail the
1385 // `old_entry.total_fee_msat > total_fee_msat` check below
1386 hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
1387 total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);
1390 let channel_usage = ChannelUsage {
1391 amount_msat: amount_to_transfer_over_msat,
1392 inflight_htlc_msat: used_liquidity_msat,
1395 let channel_penalty_msat = scorer.channel_penalty_msat(
1396 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage
1398 let path_penalty_msat = $next_hops_path_penalty_msat
1399 .saturating_add(channel_penalty_msat);
1400 let new_graph_node = RouteGraphNode {
1401 node_id: $src_node_id,
1402 lowest_fee_to_node: total_fee_msat,
1403 total_cltv_delta: hop_total_cltv_delta,
1404 value_contribution_msat,
1405 path_htlc_minimum_msat,
1407 path_length_to_node,
1410 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1411 // if this way is cheaper than the already known
1412 // (considering the cost to "reach" this channel from the route destination,
1413 // the cost of using this channel,
1414 // and the cost of routing to the source node of this channel).
1415 // Also, consider that htlc_minimum_msat_difference, because we might end up
1416 // paying it. Consider the following exploit:
1417 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1418 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1419 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1420 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1422 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1423 // but it may require additional tracking - we don't want to double-count
1424 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1425 // can't use something that may decrease on future hops.
1426 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1427 .saturating_add(old_entry.path_penalty_msat);
1428 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1429 .saturating_add(path_penalty_msat);
1431 if !old_entry.was_processed && new_cost < old_cost {
1432 targets.push(new_graph_node);
1433 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1434 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1435 old_entry.total_fee_msat = total_fee_msat;
1436 old_entry.node_id = $dest_node_id.clone();
1437 old_entry.candidate = $candidate.clone();
1438 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1439 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1440 old_entry.path_penalty_msat = path_penalty_msat;
1441 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1443 old_entry.value_contribution_msat = value_contribution_msat;
1445 did_add_update_path_to_src_node = true;
1446 } else if old_entry.was_processed && new_cost < old_cost {
1447 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1449 // If we're skipping processing a node which was previously
1450 // processed even though we found another path to it with a
1451 // cheaper fee, check that it was because the second path we
1452 // found (which we are processing now) has a lower value
1453 // contribution due to an HTLC minimum limit.
1455 // e.g. take a graph with two paths from node 1 to node 2, one
1456 // through channel A, and one through channel B. Channel A and
1457 // B are both in the to-process heap, with their scores set by
1458 // a higher htlc_minimum than fee.
1459 // Channel A is processed first, and the channels onwards from
1460 // node 1 are added to the to-process heap. Thereafter, we pop
1461 // Channel B off of the heap, note that it has a much more
1462 // restrictive htlc_maximum_msat, and recalculate the fees for
1463 // all of node 1's channels using the new, reduced, amount.
1465 // This would be bogus - we'd be selecting a higher-fee path
1466 // with a lower htlc_maximum_msat instead of the one we'd
1467 // already decided to use.
1468 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1470 value_contribution_msat + path_penalty_msat <
1471 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1479 did_add_update_path_to_src_node
1483 let default_node_features = default_node_features();
1485 // Find ways (channels with destination) to reach a given node and store them
1486 // in the corresponding data structures (routing graph etc).
1487 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1488 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1489 // This data can later be helpful to optimize routing (pay lower fees).
1490 macro_rules! add_entries_to_cheapest_to_target_node {
1491 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1492 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1493 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1494 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1495 let was_processed = elem.was_processed;
1496 elem.was_processed = true;
1499 // Entries are added to dist in add_entry!() when there is a channel from a node.
1500 // Because there are no channels from payee, it will not have a dist entry at this point.
1501 // If we're processing any other node, it is always be the result of a channel from it.
1502 assert_eq!($node_id, payee_node_id);
1507 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1508 for details in first_channels {
1509 let candidate = CandidateRouteHop::FirstHop { details };
1510 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1511 $next_hops_value_contribution,
1512 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1513 $next_hops_cltv_delta, $next_hops_path_length);
1517 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1520 &default_node_features
1523 if !features.requires_unknown_bits() {
1524 for chan_id in $node.channels.iter() {
1525 let chan = network_channels.get(chan_id).unwrap();
1526 if !chan.features.requires_unknown_bits() {
1527 if let Some((directed_channel, source)) = chan.as_directed_to(&$node_id) {
1528 if first_hops.is_none() || *source != our_node_id {
1529 if directed_channel.direction().enabled {
1530 let candidate = CandidateRouteHop::PublicHop {
1531 info: directed_channel,
1532 short_channel_id: *chan_id,
1534 add_entry!(candidate, *source, $node_id,
1535 $fee_to_target_msat,
1536 $next_hops_value_contribution,
1537 $next_hops_path_htlc_minimum_msat,
1538 $next_hops_path_penalty_msat,
1539 $next_hops_cltv_delta, $next_hops_path_length);
1550 let mut payment_paths = Vec::<PaymentPath>::new();
1552 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1553 'paths_collection: loop {
1554 // For every new path, start from scratch, except for used_channel_liquidities, which
1555 // helps to avoid reusing previously selected paths in future iterations.
1558 hit_minimum_limit = false;
1560 // If first hop is a private channel and the only way to reach the payee, this is the only
1561 // place where it could be added.
1562 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1563 for details in first_channels {
1564 let candidate = CandidateRouteHop::FirstHop { details };
1565 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat,
1567 log_trace!(logger, "{} direct route to payee via SCID {}",
1568 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1572 // Add the payee as a target, so that the payee-to-payer
1573 // search algorithm knows what to start with.
1574 match network_nodes.get(&payee_node_id) {
1575 // The payee is not in our network graph, so nothing to add here.
1576 // There is still a chance of reaching them via last_hops though,
1577 // so don't yet fail the payment here.
1578 // If not, targets.pop() will not even let us enter the loop in step 2.
1581 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0, 0);
1586 // If a caller provided us with last hops, add them to routing targets. Since this happens
1587 // earlier than general path finding, they will be somewhat prioritized, although currently
1588 // it matters only if the fees are exactly the same.
1589 let route_hints = match &payment_params.route_hints {
1590 Hints::Clear(hints) => hints,
1591 _ => return Err(LightningError{err: "Routing to blinded paths isn't supported yet".to_owned(), action: ErrorAction::IgnoreError}),
1593 for route in route_hints.iter().filter(|route| !route.0.is_empty()) {
1594 let first_hop_in_route = &(route.0)[0];
1595 let have_hop_src_in_graph =
1596 // Only add the hops in this route to our candidate set if either
1597 // we have a direct channel to the first hop or the first hop is
1598 // in the regular network graph.
1599 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1600 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1601 if have_hop_src_in_graph {
1602 // We start building the path from reverse, i.e., from payee
1603 // to the first RouteHintHop in the path.
1604 let hop_iter = route.0.iter().rev();
1605 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1606 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1607 let mut hop_used = true;
1608 let mut aggregate_next_hops_fee_msat: u64 = 0;
1609 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1610 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1611 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1612 let mut aggregate_next_hops_path_length: u8 = 0;
1614 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1615 let source = NodeId::from_pubkey(&hop.src_node_id);
1616 let target = NodeId::from_pubkey(&prev_hop_id);
1617 let candidate = network_channels
1618 .get(&hop.short_channel_id)
1619 .and_then(|channel| channel.as_directed_to(&target))
1620 .map(|(info, _)| CandidateRouteHop::PublicHop {
1622 short_channel_id: hop.short_channel_id,
1624 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1626 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
1627 path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
1628 aggregate_next_hops_path_penalty_msat,
1629 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
1630 // If this hop was not used then there is no use checking the preceding
1631 // hops in the RouteHint. We can break by just searching for a direct
1632 // channel between last checked hop and first_hop_targets.
1636 let used_liquidity_msat = used_channel_liquidities
1637 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1638 let channel_usage = ChannelUsage {
1639 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1640 inflight_htlc_msat: used_liquidity_msat,
1641 effective_capacity: candidate.effective_capacity(),
1643 let channel_penalty_msat = scorer.channel_penalty_msat(
1644 hop.short_channel_id, &source, &target, channel_usage
1646 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1647 .saturating_add(channel_penalty_msat);
1649 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1650 .saturating_add(hop.cltv_expiry_delta as u32);
1652 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1655 // Searching for a direct channel between last checked hop and first_hop_targets
1656 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1657 for details in first_channels {
1658 let candidate = CandidateRouteHop::FirstHop { details };
1659 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1660 aggregate_next_hops_fee_msat, path_value_msat,
1661 aggregate_next_hops_path_htlc_minimum_msat,
1662 aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
1663 aggregate_next_hops_path_length);
1671 // In the next values of the iterator, the aggregate fees already reflects
1672 // the sum of value sent from payer (final_value_msat) and routing fees
1673 // for the last node in the RouteHint. We need to just add the fees to
1674 // route through the current node so that the preceding node (next iteration)
1676 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1677 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1678 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1680 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1681 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1682 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1683 .checked_add(hop_htlc_minimum_msat_inc);
1684 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1686 if idx == route.0.len() - 1 {
1687 // The last hop in this iterator is the first hop in
1688 // overall RouteHint.
1689 // If this hop connects to a node with which we have a direct channel,
1690 // ignore the network graph and, if the last hop was added, add our
1691 // direct channel to the candidate set.
1693 // Note that we *must* check if the last hop was added as `add_entry`
1694 // always assumes that the third argument is a node to which we have a
1696 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1697 for details in first_channels {
1698 let candidate = CandidateRouteHop::FirstHop { details };
1699 add_entry!(candidate, our_node_id,
1700 NodeId::from_pubkey(&hop.src_node_id),
1701 aggregate_next_hops_fee_msat, path_value_msat,
1702 aggregate_next_hops_path_htlc_minimum_msat,
1703 aggregate_next_hops_path_penalty_msat,
1704 aggregate_next_hops_cltv_delta,
1705 aggregate_next_hops_path_length);
1713 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1715 // At this point, targets are filled with the data from first and
1716 // last hops communicated by the caller, and the payment receiver.
1717 let mut found_new_path = false;
1720 // If this loop terminates due the exhaustion of targets, two situations are possible:
1721 // - not enough outgoing liquidity:
1722 // 0 < already_collected_value_msat < final_value_msat
1723 // - enough outgoing liquidity:
1724 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1725 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1726 // paths_collection will be stopped because found_new_path==false.
1727 // This is not necessarily a routing failure.
1728 '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() {
1730 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1731 // traversing the graph and arrange the path out of what we found.
1732 if node_id == our_node_id {
1733 let mut new_entry = dist.remove(&our_node_id).unwrap();
1734 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1737 let mut features_set = false;
1738 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1739 for details in first_channels {
1740 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1741 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1742 features_set = true;
1748 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1749 if let Some(node_info) = node.announcement_info.as_ref() {
1750 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1752 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1755 // We can fill in features for everything except hops which were
1756 // provided via the invoice we're paying. We could guess based on the
1757 // recipient's features but for now we simply avoid guessing at all.
1761 // Means we succesfully traversed from the payer to the payee, now
1762 // save this path for the payment route. Also, update the liquidity
1763 // remaining on the used hops, so that we take them into account
1764 // while looking for more paths.
1765 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1769 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1770 Some(payment_hop) => payment_hop,
1771 // We can't arrive at None because, if we ever add an entry to targets,
1772 // we also fill in the entry in dist (see add_entry!).
1773 None => unreachable!(),
1775 // We "propagate" the fees one hop backward (topologically) here,
1776 // so that fees paid for a HTLC forwarding on the current channel are
1777 // associated with the previous channel (where they will be subtracted).
1778 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1779 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1781 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1782 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1784 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1785 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1787 let mut payment_path = PaymentPath {hops: ordered_hops};
1789 // We could have possibly constructed a slightly inconsistent path: since we reduce
1790 // value being transferred along the way, we could have violated htlc_minimum_msat
1791 // on some channels we already passed (assuming dest->source direction). Here, we
1792 // recompute the fees again, so that if that's the case, we match the currently
1793 // underpaid htlc_minimum_msat with fees.
1794 debug_assert_eq!(payment_path.get_value_msat(), value_contribution_msat);
1795 value_contribution_msat = cmp::min(value_contribution_msat, final_value_msat);
1796 payment_path.update_value_and_recompute_fees(value_contribution_msat);
1798 // Since a path allows to transfer as much value as
1799 // the smallest channel it has ("bottleneck"), we should recompute
1800 // the fees so sender HTLC don't overpay fees when traversing
1801 // larger channels than the bottleneck. This may happen because
1802 // when we were selecting those channels we were not aware how much value
1803 // this path will transfer, and the relative fee for them
1804 // might have been computed considering a larger value.
1805 // Remember that we used these channels so that we don't rely
1806 // on the same liquidity in future paths.
1807 let mut prevented_redundant_path_selection = false;
1808 let prev_hop_iter = core::iter::once(&our_node_id)
1809 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1810 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1811 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1812 let used_liquidity_msat = used_channel_liquidities
1813 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1814 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
1815 .or_insert(spent_on_hop_msat);
1816 let hop_capacity = hop.candidate.effective_capacity();
1817 let hop_max_msat = max_htlc_from_capacity(hop_capacity, channel_saturation_pow_half);
1818 if *used_liquidity_msat == hop_max_msat {
1819 // If this path used all of this channel's available liquidity, we know
1820 // this path will not be selected again in the next loop iteration.
1821 prevented_redundant_path_selection = true;
1823 debug_assert!(*used_liquidity_msat <= hop_max_msat);
1825 if !prevented_redundant_path_selection {
1826 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1827 // we'll probably end up picking the same path again on the next iteration.
1828 // Decrease the available liquidity of a hop in the middle of the path.
1829 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1830 let exhausted = u64::max_value();
1831 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1832 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
1833 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
1836 // Track the total amount all our collected paths allow to send so that we know
1837 // when to stop looking for more paths
1838 already_collected_value_msat += value_contribution_msat;
1840 payment_paths.push(payment_path);
1841 found_new_path = true;
1842 break 'path_construction;
1845 // If we found a path back to the payee, we shouldn't try to process it again. This is
1846 // the equivalent of the `elem.was_processed` check in
1847 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1848 if node_id == payee_node_id { continue 'path_construction; }
1850 // Otherwise, since the current target node is not us,
1851 // keep "unrolling" the payment graph from payee to payer by
1852 // finding a way to reach the current target from the payer side.
1853 match network_nodes.get(&node_id) {
1856 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
1857 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
1858 total_cltv_delta, path_length_to_node);
1864 if !found_new_path && channel_saturation_pow_half != 0 {
1865 channel_saturation_pow_half = 0;
1866 continue 'paths_collection;
1868 // If we don't support MPP, no use trying to gather more value ever.
1869 break 'paths_collection;
1873 // Stop either when the recommended value is reached or if no new path was found in this
1875 // In the latter case, making another path finding attempt won't help,
1876 // because we deterministically terminated the search due to low liquidity.
1877 if !found_new_path && channel_saturation_pow_half != 0 {
1878 channel_saturation_pow_half = 0;
1879 } else if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1880 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1881 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1882 break 'paths_collection;
1883 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1884 // Further, if this was our first walk of the graph, and we weren't limited by an
1885 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1886 // limited by an htlc_minimum_msat value, find another path with a higher value,
1887 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1888 // still keeping a lower total fee than this path.
1889 if !hit_minimum_limit {
1890 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1891 break 'paths_collection;
1893 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1894 path_value_msat = recommended_value_msat;
1899 if payment_paths.len() == 0 {
1900 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1903 if already_collected_value_msat < final_value_msat {
1904 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1908 let mut selected_route = payment_paths;
1910 debug_assert_eq!(selected_route.iter().map(|p| p.get_value_msat()).sum::<u64>(), already_collected_value_msat);
1911 let mut overpaid_value_msat = already_collected_value_msat - final_value_msat;
1913 // First, sort by the cost-per-value of the path, dropping the paths that cost the most for
1914 // the value they contribute towards the payment amount.
1915 // We sort in descending order as we will remove from the front in `retain`, next.
1916 selected_route.sort_unstable_by(|a, b|
1917 (((b.get_cost_msat() as u128) << 64) / (b.get_value_msat() as u128))
1918 .cmp(&(((a.get_cost_msat() as u128) << 64) / (a.get_value_msat() as u128)))
1921 // We should make sure that at least 1 path left.
1922 let mut paths_left = selected_route.len();
1923 selected_route.retain(|path| {
1924 if paths_left == 1 {
1927 let path_value_msat = path.get_value_msat();
1928 if path_value_msat <= overpaid_value_msat {
1929 overpaid_value_msat -= path_value_msat;
1935 debug_assert!(selected_route.len() > 0);
1937 if overpaid_value_msat != 0 {
1939 // Now, subtract the remaining overpaid value from the most-expensive path.
1940 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1941 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1942 selected_route.sort_unstable_by(|a, b| {
1943 let a_f = a.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
1944 let b_f = b.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>();
1945 a_f.cmp(&b_f).then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
1947 let expensive_payment_path = selected_route.first_mut().unwrap();
1949 // We already dropped all the paths with value below `overpaid_value_msat` above, thus this
1950 // can't go negative.
1951 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1952 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1956 // Sort by the path itself and combine redundant paths.
1957 // Note that we sort by SCIDs alone as its simpler but when combining we have to ensure we
1958 // compare both SCIDs and NodeIds as individual nodes may use random aliases causing collisions
1960 selected_route.sort_unstable_by_key(|path| {
1961 let mut key = [0u64; MAX_PATH_LENGTH_ESTIMATE as usize];
1962 debug_assert!(path.hops.len() <= key.len());
1963 for (scid, key) in path.hops.iter().map(|h| h.0.candidate.short_channel_id()).zip(key.iter_mut()) {
1968 for idx in 0..(selected_route.len() - 1) {
1969 if idx + 1 >= selected_route.len() { break; }
1970 if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id)),
1971 selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.short_channel_id(), h.0.node_id))) {
1972 let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
1973 selected_route[idx].update_value_and_recompute_fees(new_value);
1974 selected_route.remove(idx + 1);
1978 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1979 for payment_path in selected_route {
1980 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1982 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)})?,
1983 node_features: node_features.clone(),
1984 short_channel_id: payment_hop.candidate.short_channel_id(),
1985 channel_features: payment_hop.candidate.features(),
1986 fee_msat: payment_hop.fee_msat,
1987 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1989 }).collect::<Vec<_>>();
1990 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1991 // applicable for the previous hop.
1992 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1993 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1995 selected_paths.push(path);
1997 // Make sure we would never create a route with more paths than we allow.
1998 debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
2000 if let Some(features) = &payment_params.features {
2001 for path in selected_paths.iter_mut() {
2002 if let Ok(route_hop) = path.last_mut().unwrap() {
2003 route_hop.node_features = features.to_context();
2009 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
2010 payment_params: Some(payment_params.clone()),
2012 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
2016 // When an adversarial intermediary node observes a payment, it may be able to infer its
2017 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
2018 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
2019 // payment path by adding a randomized 'shadow route' offset to the final hop.
2020 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
2021 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
2023 let network_channels = network_graph.channels();
2024 let network_nodes = network_graph.nodes();
2026 for path in route.paths.iter_mut() {
2027 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
2029 // Remember the last three nodes of the random walk and avoid looping back on them.
2030 // Init with the last three nodes from the actual path, if possible.
2031 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.last().unwrap().pubkey),
2032 NodeId::from_pubkey(&path.get(path.len().saturating_sub(2)).unwrap().pubkey),
2033 NodeId::from_pubkey(&path.get(path.len().saturating_sub(3)).unwrap().pubkey)];
2035 // Choose the last publicly known node as the starting point for the random walk.
2036 let mut cur_hop: Option<NodeId> = None;
2037 let mut path_nonce = [0u8; 12];
2038 if let Some(starting_hop) = path.iter().rev()
2039 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
2040 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
2041 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
2044 // Init PRNG with the path-dependant nonce, which is static for private paths.
2045 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
2046 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
2048 // Pick a random path length in [1 .. 3]
2049 prng.process_in_place(&mut random_path_bytes);
2050 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
2052 for random_hop in 0..random_walk_length {
2053 // If we don't find a suitable offset in the public network graph, we default to
2054 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2055 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
2057 if let Some(cur_node_id) = cur_hop {
2058 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
2059 // Randomly choose the next unvisited hop.
2060 prng.process_in_place(&mut random_path_bytes);
2061 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
2062 .checked_rem(cur_node.channels.len())
2063 .and_then(|index| cur_node.channels.get(index))
2064 .and_then(|id| network_channels.get(id)) {
2065 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
2066 if !nodes_to_avoid.iter().any(|x| x == next_id) {
2067 nodes_to_avoid[random_hop] = *next_id;
2068 random_hop_offset = dir_info.direction().cltv_expiry_delta.into();
2069 cur_hop = Some(*next_id);
2076 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
2077 .checked_add(random_hop_offset)
2078 .unwrap_or(shadow_ctlv_expiry_delta_offset);
2081 // Limit the total offset to reduce the worst-case locked liquidity timevalue
2082 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
2083 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
2085 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
2086 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
2087 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
2088 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
2089 max_path_offset = cmp::max(
2090 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
2091 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
2092 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
2094 // Add 'shadow' CLTV offset to the final hop
2095 if let Some(last_hop) = path.last_mut() {
2096 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
2097 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
2102 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
2103 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
2105 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
2106 pub fn build_route_from_hops<L: Deref, GL: Deref>(
2107 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
2108 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
2109 ) -> Result<Route, LightningError>
2110 where L::Target: Logger, GL::Target: Logger {
2111 let graph_lock = network_graph.read_only();
2112 let mut route = build_route_from_hops_internal(
2113 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
2114 route_params.final_value_msat, route_params.payment_params.final_cltv_expiry_delta,
2115 logger, random_seed_bytes)?;
2116 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
2120 fn build_route_from_hops_internal<L: Deref>(
2121 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
2122 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
2123 logger: L, random_seed_bytes: &[u8; 32]
2124 ) -> Result<Route, LightningError> where L::Target: Logger {
2127 our_node_id: NodeId,
2128 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
2131 impl Score for HopScorer {
2132 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
2133 _usage: ChannelUsage) -> u64
2135 let mut cur_id = self.our_node_id;
2136 for i in 0..self.hop_ids.len() {
2137 if let Some(next_id) = self.hop_ids[i] {
2138 if cur_id == *source && next_id == *target {
2149 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
2151 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
2153 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
2155 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
2158 impl<'a> Writeable for HopScorer {
2160 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
2165 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
2166 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
2169 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
2170 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
2171 for i in 0..hops.len() {
2172 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
2175 let scorer = HopScorer { our_node_id, hop_ids };
2177 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
2178 final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
2183 use crate::routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
2184 use crate::routing::utxo::UtxoResult;
2185 use crate::routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
2186 PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
2187 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
2188 use crate::routing::scoring::{ChannelUsage, FixedPenaltyScorer, Score, ProbabilisticScorer, ProbabilisticScoringParameters};
2189 use crate::routing::test_utils::{add_channel, add_or_update_node, build_graph, build_line_graph, id_to_feature_flags, get_nodes, update_channel};
2190 use crate::chain::transaction::OutPoint;
2191 use crate::chain::keysinterface::EntropySource;
2192 use crate::ln::features::{ChannelFeatures, InitFeatures, NodeFeatures};
2193 use crate::ln::msgs::{ErrorAction, LightningError, UnsignedChannelUpdate, MAX_VALUE_MSAT};
2194 use crate::ln::channelmanager;
2195 use crate::util::config::UserConfig;
2196 use crate::util::test_utils as ln_test_utils;
2197 use crate::util::chacha20::ChaCha20;
2199 use crate::util::ser::{Writeable, Writer};
2201 use bitcoin::hashes::Hash;
2202 use bitcoin::network::constants::Network;
2203 use bitcoin::blockdata::constants::genesis_block;
2204 use bitcoin::blockdata::script::Builder;
2205 use bitcoin::blockdata::opcodes;
2206 use bitcoin::blockdata::transaction::TxOut;
2210 use bitcoin::secp256k1::{PublicKey,SecretKey};
2211 use bitcoin::secp256k1::Secp256k1;
2213 use crate::prelude::*;
2214 use crate::sync::Arc;
2216 use core::convert::TryInto;
2218 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
2219 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
2220 channelmanager::ChannelDetails {
2221 channel_id: [0; 32],
2222 counterparty: channelmanager::ChannelCounterparty {
2225 unspendable_punishment_reserve: 0,
2226 forwarding_info: None,
2227 outbound_htlc_minimum_msat: None,
2228 outbound_htlc_maximum_msat: None,
2230 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
2233 outbound_scid_alias: None,
2234 inbound_scid_alias: None,
2235 channel_value_satoshis: 0,
2238 outbound_capacity_msat,
2239 next_outbound_htlc_limit_msat: outbound_capacity_msat,
2240 inbound_capacity_msat: 42,
2241 unspendable_punishment_reserve: None,
2242 confirmations_required: None,
2243 confirmations: None,
2244 force_close_spend_delay: None,
2245 is_outbound: true, is_channel_ready: true,
2246 is_usable: true, is_public: true,
2247 inbound_htlc_minimum_msat: None,
2248 inbound_htlc_maximum_msat: None,
2250 feerate_sat_per_1000_weight: None
2255 fn simple_route_test() {
2256 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2257 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2258 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2259 let scorer = ln_test_utils::TestScorer::new();
2260 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2261 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2263 // Simple route to 2 via 1
2265 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) {
2266 assert_eq!(err, "Cannot send a payment of 0 msat");
2267 } else { panic!(); }
2269 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2270 assert_eq!(route.paths[0].len(), 2);
2272 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2273 assert_eq!(route.paths[0][0].short_channel_id, 2);
2274 assert_eq!(route.paths[0][0].fee_msat, 100);
2275 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2276 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2277 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2279 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2280 assert_eq!(route.paths[0][1].short_channel_id, 4);
2281 assert_eq!(route.paths[0][1].fee_msat, 100);
2282 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2283 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2284 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2288 fn invalid_first_hop_test() {
2289 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2290 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2291 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2292 let scorer = ln_test_utils::TestScorer::new();
2293 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2294 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2296 // Simple route to 2 via 1
2298 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2300 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2301 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) {
2302 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2303 } else { panic!(); }
2305 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2306 assert_eq!(route.paths[0].len(), 2);
2310 fn htlc_minimum_test() {
2311 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2312 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2313 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2314 let scorer = ln_test_utils::TestScorer::new();
2315 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2316 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2318 // Simple route to 2 via 1
2320 // Disable other paths
2321 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2323 short_channel_id: 12,
2325 flags: 2, // to disable
2326 cltv_expiry_delta: 0,
2327 htlc_minimum_msat: 0,
2328 htlc_maximum_msat: MAX_VALUE_MSAT,
2330 fee_proportional_millionths: 0,
2331 excess_data: Vec::new()
2333 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2334 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2335 short_channel_id: 3,
2337 flags: 2, // to disable
2338 cltv_expiry_delta: 0,
2339 htlc_minimum_msat: 0,
2340 htlc_maximum_msat: MAX_VALUE_MSAT,
2342 fee_proportional_millionths: 0,
2343 excess_data: Vec::new()
2345 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2346 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2347 short_channel_id: 13,
2349 flags: 2, // to disable
2350 cltv_expiry_delta: 0,
2351 htlc_minimum_msat: 0,
2352 htlc_maximum_msat: MAX_VALUE_MSAT,
2354 fee_proportional_millionths: 0,
2355 excess_data: Vec::new()
2357 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2358 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2359 short_channel_id: 6,
2361 flags: 2, // to disable
2362 cltv_expiry_delta: 0,
2363 htlc_minimum_msat: 0,
2364 htlc_maximum_msat: MAX_VALUE_MSAT,
2366 fee_proportional_millionths: 0,
2367 excess_data: Vec::new()
2369 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2370 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2371 short_channel_id: 7,
2373 flags: 2, // to disable
2374 cltv_expiry_delta: 0,
2375 htlc_minimum_msat: 0,
2376 htlc_maximum_msat: MAX_VALUE_MSAT,
2378 fee_proportional_millionths: 0,
2379 excess_data: Vec::new()
2382 // Check against amount_to_transfer_over_msat.
2383 // Set minimal HTLC of 200_000_000 msat.
2384 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2385 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2386 short_channel_id: 2,
2389 cltv_expiry_delta: 0,
2390 htlc_minimum_msat: 200_000_000,
2391 htlc_maximum_msat: MAX_VALUE_MSAT,
2393 fee_proportional_millionths: 0,
2394 excess_data: Vec::new()
2397 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2399 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2400 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2401 short_channel_id: 4,
2404 cltv_expiry_delta: 0,
2405 htlc_minimum_msat: 0,
2406 htlc_maximum_msat: 199_999_999,
2408 fee_proportional_millionths: 0,
2409 excess_data: Vec::new()
2412 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2413 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) {
2414 assert_eq!(err, "Failed to find a path to the given destination");
2415 } else { panic!(); }
2417 // Lift the restriction on the first hop.
2418 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2419 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2420 short_channel_id: 2,
2423 cltv_expiry_delta: 0,
2424 htlc_minimum_msat: 0,
2425 htlc_maximum_msat: MAX_VALUE_MSAT,
2427 fee_proportional_millionths: 0,
2428 excess_data: Vec::new()
2431 // A payment above the minimum should pass
2432 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();
2433 assert_eq!(route.paths[0].len(), 2);
2437 fn htlc_minimum_overpay_test() {
2438 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2439 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2440 let config = UserConfig::default();
2441 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
2442 let scorer = ln_test_utils::TestScorer::new();
2443 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2444 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2446 // A route to node#2 via two paths.
2447 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2448 // Thus, they can't send 60 without overpaying.
2449 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2451 short_channel_id: 2,
2454 cltv_expiry_delta: 0,
2455 htlc_minimum_msat: 35_000,
2456 htlc_maximum_msat: 40_000,
2458 fee_proportional_millionths: 0,
2459 excess_data: Vec::new()
2461 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2462 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2463 short_channel_id: 12,
2466 cltv_expiry_delta: 0,
2467 htlc_minimum_msat: 35_000,
2468 htlc_maximum_msat: 40_000,
2470 fee_proportional_millionths: 0,
2471 excess_data: Vec::new()
2475 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2476 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2477 short_channel_id: 13,
2480 cltv_expiry_delta: 0,
2481 htlc_minimum_msat: 0,
2482 htlc_maximum_msat: MAX_VALUE_MSAT,
2484 fee_proportional_millionths: 0,
2485 excess_data: Vec::new()
2487 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2488 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2489 short_channel_id: 4,
2492 cltv_expiry_delta: 0,
2493 htlc_minimum_msat: 0,
2494 htlc_maximum_msat: MAX_VALUE_MSAT,
2496 fee_proportional_millionths: 0,
2497 excess_data: Vec::new()
2500 // Disable other paths
2501 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2502 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2503 short_channel_id: 1,
2505 flags: 2, // to disable
2506 cltv_expiry_delta: 0,
2507 htlc_minimum_msat: 0,
2508 htlc_maximum_msat: MAX_VALUE_MSAT,
2510 fee_proportional_millionths: 0,
2511 excess_data: Vec::new()
2514 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2515 // Overpay fees to hit htlc_minimum_msat.
2516 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2517 // TODO: this could be better balanced to overpay 10k and not 15k.
2518 assert_eq!(overpaid_fees, 15_000);
2520 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2521 // while taking even more fee to match htlc_minimum_msat.
2522 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2523 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2524 short_channel_id: 12,
2527 cltv_expiry_delta: 0,
2528 htlc_minimum_msat: 65_000,
2529 htlc_maximum_msat: 80_000,
2531 fee_proportional_millionths: 0,
2532 excess_data: Vec::new()
2534 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2535 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2536 short_channel_id: 2,
2539 cltv_expiry_delta: 0,
2540 htlc_minimum_msat: 0,
2541 htlc_maximum_msat: MAX_VALUE_MSAT,
2543 fee_proportional_millionths: 0,
2544 excess_data: Vec::new()
2546 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2547 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2548 short_channel_id: 4,
2551 cltv_expiry_delta: 0,
2552 htlc_minimum_msat: 0,
2553 htlc_maximum_msat: MAX_VALUE_MSAT,
2555 fee_proportional_millionths: 100_000,
2556 excess_data: Vec::new()
2559 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2560 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2561 assert_eq!(route.paths.len(), 1);
2562 assert_eq!(route.paths[0][0].short_channel_id, 12);
2563 let fees = route.paths[0][0].fee_msat;
2564 assert_eq!(fees, 5_000);
2566 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2567 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2568 // the other channel.
2569 assert_eq!(route.paths.len(), 1);
2570 assert_eq!(route.paths[0][0].short_channel_id, 2);
2571 let fees = route.paths[0][0].fee_msat;
2572 assert_eq!(fees, 5_000);
2576 fn disable_channels_test() {
2577 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2578 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2579 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2580 let scorer = ln_test_utils::TestScorer::new();
2581 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2582 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2584 // // Disable channels 4 and 12 by flags=2
2585 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2586 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2587 short_channel_id: 4,
2589 flags: 2, // to disable
2590 cltv_expiry_delta: 0,
2591 htlc_minimum_msat: 0,
2592 htlc_maximum_msat: MAX_VALUE_MSAT,
2594 fee_proportional_millionths: 0,
2595 excess_data: Vec::new()
2597 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2598 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2599 short_channel_id: 12,
2601 flags: 2, // to disable
2602 cltv_expiry_delta: 0,
2603 htlc_minimum_msat: 0,
2604 htlc_maximum_msat: MAX_VALUE_MSAT,
2606 fee_proportional_millionths: 0,
2607 excess_data: Vec::new()
2610 // If all the channels require some features we don't understand, route should fail
2611 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) {
2612 assert_eq!(err, "Failed to find a path to the given destination");
2613 } else { panic!(); }
2615 // If we specify a channel to node7, that overrides our local channel view and that gets used
2616 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2617 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();
2618 assert_eq!(route.paths[0].len(), 2);
2620 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2621 assert_eq!(route.paths[0][0].short_channel_id, 42);
2622 assert_eq!(route.paths[0][0].fee_msat, 200);
2623 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2624 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2625 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2627 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2628 assert_eq!(route.paths[0][1].short_channel_id, 13);
2629 assert_eq!(route.paths[0][1].fee_msat, 100);
2630 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2631 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2632 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2636 fn disable_node_test() {
2637 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2638 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2639 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2640 let scorer = ln_test_utils::TestScorer::new();
2641 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2642 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2644 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2645 let mut unknown_features = NodeFeatures::empty();
2646 unknown_features.set_unknown_feature_required();
2647 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2648 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2649 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2651 // If all nodes require some features we don't understand, route should fail
2652 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) {
2653 assert_eq!(err, "Failed to find a path to the given destination");
2654 } else { panic!(); }
2656 // If we specify a channel to node7, that overrides our local channel view and that gets used
2657 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2658 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();
2659 assert_eq!(route.paths[0].len(), 2);
2661 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2662 assert_eq!(route.paths[0][0].short_channel_id, 42);
2663 assert_eq!(route.paths[0][0].fee_msat, 200);
2664 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2665 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2666 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2668 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2669 assert_eq!(route.paths[0][1].short_channel_id, 13);
2670 assert_eq!(route.paths[0][1].fee_msat, 100);
2671 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2672 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2673 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2675 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2676 // naively) assume that the user checked the feature bits on the invoice, which override
2677 // the node_announcement.
2681 fn our_chans_test() {
2682 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2683 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2684 let scorer = ln_test_utils::TestScorer::new();
2685 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2686 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2688 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2689 let payment_params = PaymentParameters::from_node_id(nodes[0], 42);
2690 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2691 assert_eq!(route.paths[0].len(), 3);
2693 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2694 assert_eq!(route.paths[0][0].short_channel_id, 2);
2695 assert_eq!(route.paths[0][0].fee_msat, 200);
2696 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2697 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2698 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2700 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2701 assert_eq!(route.paths[0][1].short_channel_id, 4);
2702 assert_eq!(route.paths[0][1].fee_msat, 100);
2703 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2704 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2705 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2707 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2708 assert_eq!(route.paths[0][2].short_channel_id, 3);
2709 assert_eq!(route.paths[0][2].fee_msat, 100);
2710 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2711 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2712 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2714 // If we specify a channel to node7, that overrides our local channel view and that gets used
2715 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
2716 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2717 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();
2718 assert_eq!(route.paths[0].len(), 2);
2720 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2721 assert_eq!(route.paths[0][0].short_channel_id, 42);
2722 assert_eq!(route.paths[0][0].fee_msat, 200);
2723 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2724 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2725 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2727 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2728 assert_eq!(route.paths[0][1].short_channel_id, 13);
2729 assert_eq!(route.paths[0][1].fee_msat, 100);
2730 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2731 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2732 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2735 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2736 let zero_fees = RoutingFees {
2738 proportional_millionths: 0,
2740 vec![RouteHint(vec![RouteHintHop {
2741 src_node_id: nodes[3],
2742 short_channel_id: 8,
2744 cltv_expiry_delta: (8 << 4) | 1,
2745 htlc_minimum_msat: None,
2746 htlc_maximum_msat: None,
2748 ]), RouteHint(vec![RouteHintHop {
2749 src_node_id: nodes[4],
2750 short_channel_id: 9,
2753 proportional_millionths: 0,
2755 cltv_expiry_delta: (9 << 4) | 1,
2756 htlc_minimum_msat: None,
2757 htlc_maximum_msat: None,
2758 }]), RouteHint(vec![RouteHintHop {
2759 src_node_id: nodes[5],
2760 short_channel_id: 10,
2762 cltv_expiry_delta: (10 << 4) | 1,
2763 htlc_minimum_msat: None,
2764 htlc_maximum_msat: None,
2768 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2769 let zero_fees = RoutingFees {
2771 proportional_millionths: 0,
2773 vec![RouteHint(vec![RouteHintHop {
2774 src_node_id: nodes[2],
2775 short_channel_id: 5,
2778 proportional_millionths: 0,
2780 cltv_expiry_delta: (5 << 4) | 1,
2781 htlc_minimum_msat: None,
2782 htlc_maximum_msat: None,
2784 src_node_id: nodes[3],
2785 short_channel_id: 8,
2787 cltv_expiry_delta: (8 << 4) | 1,
2788 htlc_minimum_msat: None,
2789 htlc_maximum_msat: None,
2791 ]), RouteHint(vec![RouteHintHop {
2792 src_node_id: nodes[4],
2793 short_channel_id: 9,
2796 proportional_millionths: 0,
2798 cltv_expiry_delta: (9 << 4) | 1,
2799 htlc_minimum_msat: None,
2800 htlc_maximum_msat: None,
2801 }]), RouteHint(vec![RouteHintHop {
2802 src_node_id: nodes[5],
2803 short_channel_id: 10,
2805 cltv_expiry_delta: (10 << 4) | 1,
2806 htlc_minimum_msat: None,
2807 htlc_maximum_msat: None,
2812 fn partial_route_hint_test() {
2813 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2814 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2815 let scorer = ln_test_utils::TestScorer::new();
2816 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2817 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2819 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2820 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2821 // RouteHint may be partially used by the algo to build the best path.
2823 // First check that last hop can't have its source as the payee.
2824 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2825 src_node_id: nodes[6],
2826 short_channel_id: 8,
2829 proportional_millionths: 0,
2831 cltv_expiry_delta: (8 << 4) | 1,
2832 htlc_minimum_msat: None,
2833 htlc_maximum_msat: None,
2836 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2837 invalid_last_hops.push(invalid_last_hop);
2839 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(invalid_last_hops);
2840 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) {
2841 assert_eq!(err, "Route hint cannot have the payee as the source.");
2842 } else { panic!(); }
2845 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_multi_private_channels(&nodes));
2846 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2847 assert_eq!(route.paths[0].len(), 5);
2849 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2850 assert_eq!(route.paths[0][0].short_channel_id, 2);
2851 assert_eq!(route.paths[0][0].fee_msat, 100);
2852 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2853 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2854 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2856 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2857 assert_eq!(route.paths[0][1].short_channel_id, 4);
2858 assert_eq!(route.paths[0][1].fee_msat, 0);
2859 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2860 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2861 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2863 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2864 assert_eq!(route.paths[0][2].short_channel_id, 6);
2865 assert_eq!(route.paths[0][2].fee_msat, 0);
2866 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2867 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2868 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2870 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2871 assert_eq!(route.paths[0][3].short_channel_id, 11);
2872 assert_eq!(route.paths[0][3].fee_msat, 0);
2873 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2874 // If we have a peer in the node map, we'll use their features here since we don't have
2875 // a way of figuring out their features from the invoice:
2876 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2877 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2879 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2880 assert_eq!(route.paths[0][4].short_channel_id, 8);
2881 assert_eq!(route.paths[0][4].fee_msat, 100);
2882 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2883 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2884 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2887 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2888 let zero_fees = RoutingFees {
2890 proportional_millionths: 0,
2892 vec![RouteHint(vec![RouteHintHop {
2893 src_node_id: nodes[3],
2894 short_channel_id: 8,
2896 cltv_expiry_delta: (8 << 4) | 1,
2897 htlc_minimum_msat: None,
2898 htlc_maximum_msat: None,
2899 }]), RouteHint(vec![
2901 ]), RouteHint(vec![RouteHintHop {
2902 src_node_id: nodes[5],
2903 short_channel_id: 10,
2905 cltv_expiry_delta: (10 << 4) | 1,
2906 htlc_minimum_msat: None,
2907 htlc_maximum_msat: None,
2912 fn ignores_empty_last_hops_test() {
2913 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2914 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2915 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(empty_last_hop(&nodes));
2916 let scorer = ln_test_utils::TestScorer::new();
2917 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2918 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2920 // Test handling of an empty RouteHint passed in Invoice.
2922 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2923 assert_eq!(route.paths[0].len(), 5);
2925 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2926 assert_eq!(route.paths[0][0].short_channel_id, 2);
2927 assert_eq!(route.paths[0][0].fee_msat, 100);
2928 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2929 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2930 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2932 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2933 assert_eq!(route.paths[0][1].short_channel_id, 4);
2934 assert_eq!(route.paths[0][1].fee_msat, 0);
2935 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2936 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2937 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2939 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2940 assert_eq!(route.paths[0][2].short_channel_id, 6);
2941 assert_eq!(route.paths[0][2].fee_msat, 0);
2942 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2943 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2944 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2946 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2947 assert_eq!(route.paths[0][3].short_channel_id, 11);
2948 assert_eq!(route.paths[0][3].fee_msat, 0);
2949 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2950 // If we have a peer in the node map, we'll use their features here since we don't have
2951 // a way of figuring out their features from the invoice:
2952 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2953 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2955 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2956 assert_eq!(route.paths[0][4].short_channel_id, 8);
2957 assert_eq!(route.paths[0][4].fee_msat, 100);
2958 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2959 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2960 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2963 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
2965 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
2966 let zero_fees = RoutingFees {
2968 proportional_millionths: 0,
2970 vec![RouteHint(vec![RouteHintHop {
2971 src_node_id: hint_hops[0],
2972 short_channel_id: 0xff00,
2975 proportional_millionths: 0,
2977 cltv_expiry_delta: (5 << 4) | 1,
2978 htlc_minimum_msat: None,
2979 htlc_maximum_msat: None,
2981 src_node_id: hint_hops[1],
2982 short_channel_id: 0xff01,
2984 cltv_expiry_delta: (8 << 4) | 1,
2985 htlc_minimum_msat: None,
2986 htlc_maximum_msat: None,
2991 fn multi_hint_last_hops_test() {
2992 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2993 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2994 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
2995 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
2996 let scorer = ln_test_utils::TestScorer::new();
2997 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2998 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2999 // Test through channels 2, 3, 0xff00, 0xff01.
3000 // Test shows that multiple hop hints are considered.
3002 // Disabling channels 6 & 7 by flags=2
3003 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3004 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3005 short_channel_id: 6,
3007 flags: 2, // to disable
3008 cltv_expiry_delta: 0,
3009 htlc_minimum_msat: 0,
3010 htlc_maximum_msat: MAX_VALUE_MSAT,
3012 fee_proportional_millionths: 0,
3013 excess_data: Vec::new()
3015 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3016 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3017 short_channel_id: 7,
3019 flags: 2, // to disable
3020 cltv_expiry_delta: 0,
3021 htlc_minimum_msat: 0,
3022 htlc_maximum_msat: MAX_VALUE_MSAT,
3024 fee_proportional_millionths: 0,
3025 excess_data: Vec::new()
3028 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3029 assert_eq!(route.paths[0].len(), 4);
3031 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3032 assert_eq!(route.paths[0][0].short_channel_id, 2);
3033 assert_eq!(route.paths[0][0].fee_msat, 200);
3034 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3035 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3036 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3038 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3039 assert_eq!(route.paths[0][1].short_channel_id, 4);
3040 assert_eq!(route.paths[0][1].fee_msat, 100);
3041 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3042 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3043 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3045 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
3046 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3047 assert_eq!(route.paths[0][2].fee_msat, 0);
3048 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3049 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
3050 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3052 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3053 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3054 assert_eq!(route.paths[0][3].fee_msat, 100);
3055 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3056 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3057 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3061 fn private_multi_hint_last_hops_test() {
3062 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3063 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3065 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3066 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3068 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3069 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
3070 let scorer = ln_test_utils::TestScorer::new();
3071 // Test through channels 2, 3, 0xff00, 0xff01.
3072 // Test shows that multiple hop hints are considered.
3074 // Disabling channels 6 & 7 by flags=2
3075 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3076 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3077 short_channel_id: 6,
3079 flags: 2, // to disable
3080 cltv_expiry_delta: 0,
3081 htlc_minimum_msat: 0,
3082 htlc_maximum_msat: MAX_VALUE_MSAT,
3084 fee_proportional_millionths: 0,
3085 excess_data: Vec::new()
3087 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3088 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3089 short_channel_id: 7,
3091 flags: 2, // to disable
3092 cltv_expiry_delta: 0,
3093 htlc_minimum_msat: 0,
3094 htlc_maximum_msat: MAX_VALUE_MSAT,
3096 fee_proportional_millionths: 0,
3097 excess_data: Vec::new()
3100 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3101 assert_eq!(route.paths[0].len(), 4);
3103 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3104 assert_eq!(route.paths[0][0].short_channel_id, 2);
3105 assert_eq!(route.paths[0][0].fee_msat, 200);
3106 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3107 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3108 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3110 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3111 assert_eq!(route.paths[0][1].short_channel_id, 4);
3112 assert_eq!(route.paths[0][1].fee_msat, 100);
3113 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3114 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3115 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3117 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
3118 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3119 assert_eq!(route.paths[0][2].fee_msat, 0);
3120 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3121 assert_eq!(route.paths[0][2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3122 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3124 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3125 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3126 assert_eq!(route.paths[0][3].fee_msat, 100);
3127 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3128 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3129 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3132 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3133 let zero_fees = RoutingFees {
3135 proportional_millionths: 0,
3137 vec![RouteHint(vec![RouteHintHop {
3138 src_node_id: nodes[4],
3139 short_channel_id: 11,
3141 cltv_expiry_delta: (11 << 4) | 1,
3142 htlc_minimum_msat: None,
3143 htlc_maximum_msat: None,
3145 src_node_id: nodes[3],
3146 short_channel_id: 8,
3148 cltv_expiry_delta: (8 << 4) | 1,
3149 htlc_minimum_msat: None,
3150 htlc_maximum_msat: None,
3151 }]), RouteHint(vec![RouteHintHop {
3152 src_node_id: nodes[4],
3153 short_channel_id: 9,
3156 proportional_millionths: 0,
3158 cltv_expiry_delta: (9 << 4) | 1,
3159 htlc_minimum_msat: None,
3160 htlc_maximum_msat: None,
3161 }]), RouteHint(vec![RouteHintHop {
3162 src_node_id: nodes[5],
3163 short_channel_id: 10,
3165 cltv_expiry_delta: (10 << 4) | 1,
3166 htlc_minimum_msat: None,
3167 htlc_maximum_msat: None,
3172 fn last_hops_with_public_channel_test() {
3173 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3174 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3175 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops_with_public_channel(&nodes));
3176 let scorer = ln_test_utils::TestScorer::new();
3177 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3178 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3179 // This test shows that public routes can be present in the invoice
3180 // which would be handled in the same manner.
3182 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3183 assert_eq!(route.paths[0].len(), 5);
3185 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3186 assert_eq!(route.paths[0][0].short_channel_id, 2);
3187 assert_eq!(route.paths[0][0].fee_msat, 100);
3188 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3189 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3190 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3192 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3193 assert_eq!(route.paths[0][1].short_channel_id, 4);
3194 assert_eq!(route.paths[0][1].fee_msat, 0);
3195 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3196 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3197 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3199 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3200 assert_eq!(route.paths[0][2].short_channel_id, 6);
3201 assert_eq!(route.paths[0][2].fee_msat, 0);
3202 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3203 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3204 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3206 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3207 assert_eq!(route.paths[0][3].short_channel_id, 11);
3208 assert_eq!(route.paths[0][3].fee_msat, 0);
3209 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3210 // If we have a peer in the node map, we'll use their features here since we don't have
3211 // a way of figuring out their features from the invoice:
3212 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3213 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3215 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3216 assert_eq!(route.paths[0][4].short_channel_id, 8);
3217 assert_eq!(route.paths[0][4].fee_msat, 100);
3218 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3219 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3220 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3224 fn our_chans_last_hop_connect_test() {
3225 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3226 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3227 let scorer = ln_test_utils::TestScorer::new();
3228 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3229 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3231 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3232 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3233 let mut last_hops = last_hops(&nodes);
3234 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops.clone());
3235 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();
3236 assert_eq!(route.paths[0].len(), 2);
3238 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3239 assert_eq!(route.paths[0][0].short_channel_id, 42);
3240 assert_eq!(route.paths[0][0].fee_msat, 0);
3241 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3242 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3243 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3245 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3246 assert_eq!(route.paths[0][1].short_channel_id, 8);
3247 assert_eq!(route.paths[0][1].fee_msat, 100);
3248 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3249 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3250 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3252 last_hops[0].0[0].fees.base_msat = 1000;
3254 // Revert to via 6 as the fee on 8 goes up
3255 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops);
3256 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3257 assert_eq!(route.paths[0].len(), 4);
3259 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3260 assert_eq!(route.paths[0][0].short_channel_id, 2);
3261 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3262 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3263 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3264 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3266 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3267 assert_eq!(route.paths[0][1].short_channel_id, 4);
3268 assert_eq!(route.paths[0][1].fee_msat, 100);
3269 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3270 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3271 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3273 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3274 assert_eq!(route.paths[0][2].short_channel_id, 7);
3275 assert_eq!(route.paths[0][2].fee_msat, 0);
3276 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3277 // If we have a peer in the node map, we'll use their features here since we don't have
3278 // a way of figuring out their features from the invoice:
3279 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3280 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3282 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3283 assert_eq!(route.paths[0][3].short_channel_id, 10);
3284 assert_eq!(route.paths[0][3].fee_msat, 100);
3285 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3286 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3287 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3289 // ...but still use 8 for larger payments as 6 has a variable feerate
3290 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3291 assert_eq!(route.paths[0].len(), 5);
3293 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3294 assert_eq!(route.paths[0][0].short_channel_id, 2);
3295 assert_eq!(route.paths[0][0].fee_msat, 3000);
3296 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3297 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3298 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3300 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3301 assert_eq!(route.paths[0][1].short_channel_id, 4);
3302 assert_eq!(route.paths[0][1].fee_msat, 0);
3303 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3304 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3305 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3307 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3308 assert_eq!(route.paths[0][2].short_channel_id, 6);
3309 assert_eq!(route.paths[0][2].fee_msat, 0);
3310 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3311 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3312 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3314 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3315 assert_eq!(route.paths[0][3].short_channel_id, 11);
3316 assert_eq!(route.paths[0][3].fee_msat, 1000);
3317 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3318 // If we have a peer in the node map, we'll use their features here since we don't have
3319 // a way of figuring out their features from the invoice:
3320 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3321 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3323 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3324 assert_eq!(route.paths[0][4].short_channel_id, 8);
3325 assert_eq!(route.paths[0][4].fee_msat, 2000);
3326 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3327 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3328 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3331 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> {
3332 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3333 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3334 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3336 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3337 let last_hops = RouteHint(vec![RouteHintHop {
3338 src_node_id: middle_node_id,
3339 short_channel_id: 8,
3342 proportional_millionths: last_hop_fee_prop,
3344 cltv_expiry_delta: (8 << 4) | 1,
3345 htlc_minimum_msat: None,
3346 htlc_maximum_msat: last_hop_htlc_max,
3348 let payment_params = PaymentParameters::from_node_id(target_node_id, 42).with_route_hints(vec![last_hops]);
3349 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3350 let scorer = ln_test_utils::TestScorer::new();
3351 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3352 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3353 let logger = ln_test_utils::TestLogger::new();
3354 let network_graph = NetworkGraph::new(Network::Testnet, &logger);
3355 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3356 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &logger, &scorer, &random_seed_bytes);
3361 fn unannounced_path_test() {
3362 // We should be able to send a payment to a destination without any help of a routing graph
3363 // if we have a channel with a common counterparty that appears in the first and last hop
3365 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3367 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3368 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3369 assert_eq!(route.paths[0].len(), 2);
3371 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3372 assert_eq!(route.paths[0][0].short_channel_id, 42);
3373 assert_eq!(route.paths[0][0].fee_msat, 1001);
3374 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3375 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3376 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3378 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3379 assert_eq!(route.paths[0][1].short_channel_id, 8);
3380 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3381 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3382 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3383 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3387 fn overflow_unannounced_path_test_liquidity_underflow() {
3388 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3389 // the last-hop had a fee which overflowed a u64, we'd panic.
3390 // This was due to us adding the first-hop from us unconditionally, causing us to think
3391 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3392 // In this test, we previously hit a subtraction underflow due to having less available
3393 // liquidity at the last hop than 0.
3394 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());
3398 fn overflow_unannounced_path_test_feerate_overflow() {
3399 // This tests for the same case as above, except instead of hitting a subtraction
3400 // underflow, we hit a case where the fee charged at a hop overflowed.
3401 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());
3405 fn available_amount_while_routing_test() {
3406 // Tests whether we choose the correct available channel amount while routing.
3408 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3409 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3410 let scorer = ln_test_utils::TestScorer::new();
3411 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3412 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3413 let config = UserConfig::default();
3414 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
3416 // We will use a simple single-path route from
3417 // our node to node2 via node0: channels {1, 3}.
3419 // First disable all other paths.
3420 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3421 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3422 short_channel_id: 2,
3425 cltv_expiry_delta: 0,
3426 htlc_minimum_msat: 0,
3427 htlc_maximum_msat: 100_000,
3429 fee_proportional_millionths: 0,
3430 excess_data: Vec::new()
3432 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3433 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3434 short_channel_id: 12,
3437 cltv_expiry_delta: 0,
3438 htlc_minimum_msat: 0,
3439 htlc_maximum_msat: 100_000,
3441 fee_proportional_millionths: 0,
3442 excess_data: Vec::new()
3445 // Make the first channel (#1) very permissive,
3446 // and we will be testing all limits on the second channel.
3447 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3448 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3449 short_channel_id: 1,
3452 cltv_expiry_delta: 0,
3453 htlc_minimum_msat: 0,
3454 htlc_maximum_msat: 1_000_000_000,
3456 fee_proportional_millionths: 0,
3457 excess_data: Vec::new()
3460 // First, let's see if routing works if we have absolutely no idea about the available amount.
3461 // In this case, it should be set to 250_000 sats.
3462 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3464 short_channel_id: 3,
3467 cltv_expiry_delta: 0,
3468 htlc_minimum_msat: 0,
3469 htlc_maximum_msat: 250_000_000,
3471 fee_proportional_millionths: 0,
3472 excess_data: Vec::new()
3476 // Attempt to route more than available results in a failure.
3477 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3478 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3479 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3480 } else { panic!(); }
3484 // Now, attempt to route an exact amount we have should be fine.
3485 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();
3486 assert_eq!(route.paths.len(), 1);
3487 let path = route.paths.last().unwrap();
3488 assert_eq!(path.len(), 2);
3489 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3490 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3493 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3494 // Disable channel #1 and use another first hop.
3495 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3496 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3497 short_channel_id: 1,
3500 cltv_expiry_delta: 0,
3501 htlc_minimum_msat: 0,
3502 htlc_maximum_msat: 1_000_000_000,
3504 fee_proportional_millionths: 0,
3505 excess_data: Vec::new()
3508 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3509 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3512 // Attempt to route more than available results in a failure.
3513 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3514 &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) {
3515 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3516 } else { panic!(); }
3520 // Now, attempt to route an exact amount we have should be fine.
3521 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();
3522 assert_eq!(route.paths.len(), 1);
3523 let path = route.paths.last().unwrap();
3524 assert_eq!(path.len(), 2);
3525 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3526 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3529 // Enable channel #1 back.
3530 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3531 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3532 short_channel_id: 1,
3535 cltv_expiry_delta: 0,
3536 htlc_minimum_msat: 0,
3537 htlc_maximum_msat: 1_000_000_000,
3539 fee_proportional_millionths: 0,
3540 excess_data: Vec::new()
3544 // Now let's see if routing works if we know only htlc_maximum_msat.
3545 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3546 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3547 short_channel_id: 3,
3550 cltv_expiry_delta: 0,
3551 htlc_minimum_msat: 0,
3552 htlc_maximum_msat: 15_000,
3554 fee_proportional_millionths: 0,
3555 excess_data: Vec::new()
3559 // Attempt to route more than available results in a failure.
3560 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3561 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3562 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3563 } else { panic!(); }
3567 // Now, attempt to route an exact amount we have should be fine.
3568 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3569 assert_eq!(route.paths.len(), 1);
3570 let path = route.paths.last().unwrap();
3571 assert_eq!(path.len(), 2);
3572 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3573 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3576 // Now let's see if routing works if we know only capacity from the UTXO.
3578 // We can't change UTXO capacity on the fly, so we'll disable
3579 // the existing channel and add another one with the capacity we need.
3580 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3581 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3582 short_channel_id: 3,
3585 cltv_expiry_delta: 0,
3586 htlc_minimum_msat: 0,
3587 htlc_maximum_msat: MAX_VALUE_MSAT,
3589 fee_proportional_millionths: 0,
3590 excess_data: Vec::new()
3593 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3594 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3595 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3596 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3597 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3599 *chain_monitor.utxo_ret.lock().unwrap() =
3600 UtxoResult::Sync(Ok(TxOut { value: 15, script_pubkey: good_script.clone() }));
3601 gossip_sync.add_utxo_lookup(Some(chain_monitor));
3603 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3604 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3605 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3606 short_channel_id: 333,
3609 cltv_expiry_delta: (3 << 4) | 1,
3610 htlc_minimum_msat: 0,
3611 htlc_maximum_msat: 15_000,
3613 fee_proportional_millionths: 0,
3614 excess_data: Vec::new()
3616 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3617 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3618 short_channel_id: 333,
3621 cltv_expiry_delta: (3 << 4) | 2,
3622 htlc_minimum_msat: 0,
3623 htlc_maximum_msat: 15_000,
3625 fee_proportional_millionths: 0,
3626 excess_data: Vec::new()
3630 // Attempt to route more than available results in a failure.
3631 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3632 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3633 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3634 } else { panic!(); }
3638 // Now, attempt to route an exact amount we have should be fine.
3639 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3640 assert_eq!(route.paths.len(), 1);
3641 let path = route.paths.last().unwrap();
3642 assert_eq!(path.len(), 2);
3643 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3644 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3647 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3648 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3649 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3650 short_channel_id: 333,
3653 cltv_expiry_delta: 0,
3654 htlc_minimum_msat: 0,
3655 htlc_maximum_msat: 10_000,
3657 fee_proportional_millionths: 0,
3658 excess_data: Vec::new()
3662 // Attempt to route more than available results in a failure.
3663 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3664 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3665 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3666 } else { panic!(); }
3670 // Now, attempt to route an exact amount we have should be fine.
3671 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3672 assert_eq!(route.paths.len(), 1);
3673 let path = route.paths.last().unwrap();
3674 assert_eq!(path.len(), 2);
3675 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3676 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3681 fn available_liquidity_last_hop_test() {
3682 // Check that available liquidity properly limits the path even when only
3683 // one of the latter hops is limited.
3684 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3685 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3686 let scorer = ln_test_utils::TestScorer::new();
3687 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3688 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3689 let config = UserConfig::default();
3690 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
3692 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3693 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3694 // Total capacity: 50 sats.
3696 // Disable other potential paths.
3697 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3698 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3699 short_channel_id: 2,
3702 cltv_expiry_delta: 0,
3703 htlc_minimum_msat: 0,
3704 htlc_maximum_msat: 100_000,
3706 fee_proportional_millionths: 0,
3707 excess_data: Vec::new()
3709 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3710 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3711 short_channel_id: 7,
3714 cltv_expiry_delta: 0,
3715 htlc_minimum_msat: 0,
3716 htlc_maximum_msat: 100_000,
3718 fee_proportional_millionths: 0,
3719 excess_data: Vec::new()
3724 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3725 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3726 short_channel_id: 12,
3729 cltv_expiry_delta: 0,
3730 htlc_minimum_msat: 0,
3731 htlc_maximum_msat: 100_000,
3733 fee_proportional_millionths: 0,
3734 excess_data: Vec::new()
3736 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3737 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3738 short_channel_id: 13,
3741 cltv_expiry_delta: 0,
3742 htlc_minimum_msat: 0,
3743 htlc_maximum_msat: 100_000,
3745 fee_proportional_millionths: 0,
3746 excess_data: Vec::new()
3749 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3750 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3751 short_channel_id: 6,
3754 cltv_expiry_delta: 0,
3755 htlc_minimum_msat: 0,
3756 htlc_maximum_msat: 50_000,
3758 fee_proportional_millionths: 0,
3759 excess_data: Vec::new()
3761 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3762 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3763 short_channel_id: 11,
3766 cltv_expiry_delta: 0,
3767 htlc_minimum_msat: 0,
3768 htlc_maximum_msat: 100_000,
3770 fee_proportional_millionths: 0,
3771 excess_data: Vec::new()
3774 // Attempt to route more than available results in a failure.
3775 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3776 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3777 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3778 } else { panic!(); }
3782 // Now, attempt to route 49 sats (just a bit below the capacity).
3783 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3784 assert_eq!(route.paths.len(), 1);
3785 let mut total_amount_paid_msat = 0;
3786 for path in &route.paths {
3787 assert_eq!(path.len(), 4);
3788 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3789 total_amount_paid_msat += path.last().unwrap().fee_msat;
3791 assert_eq!(total_amount_paid_msat, 49_000);
3795 // Attempt to route an exact amount is also fine
3796 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3797 assert_eq!(route.paths.len(), 1);
3798 let mut total_amount_paid_msat = 0;
3799 for path in &route.paths {
3800 assert_eq!(path.len(), 4);
3801 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3802 total_amount_paid_msat += path.last().unwrap().fee_msat;
3804 assert_eq!(total_amount_paid_msat, 50_000);
3809 fn ignore_fee_first_hop_test() {
3810 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3811 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3812 let scorer = ln_test_utils::TestScorer::new();
3813 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3814 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3815 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
3817 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3818 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3819 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3820 short_channel_id: 1,
3823 cltv_expiry_delta: 0,
3824 htlc_minimum_msat: 0,
3825 htlc_maximum_msat: 100_000,
3826 fee_base_msat: 1_000_000,
3827 fee_proportional_millionths: 0,
3828 excess_data: Vec::new()
3830 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3831 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3832 short_channel_id: 3,
3835 cltv_expiry_delta: 0,
3836 htlc_minimum_msat: 0,
3837 htlc_maximum_msat: 50_000,
3839 fee_proportional_millionths: 0,
3840 excess_data: Vec::new()
3844 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3845 assert_eq!(route.paths.len(), 1);
3846 let mut total_amount_paid_msat = 0;
3847 for path in &route.paths {
3848 assert_eq!(path.len(), 2);
3849 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3850 total_amount_paid_msat += path.last().unwrap().fee_msat;
3852 assert_eq!(total_amount_paid_msat, 50_000);
3857 fn simple_mpp_route_test() {
3858 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3859 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3860 let scorer = ln_test_utils::TestScorer::new();
3861 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3862 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3863 let config = UserConfig::default();
3864 let payment_params = PaymentParameters::from_node_id(nodes[2], 42)
3865 .with_features(channelmanager::provided_invoice_features(&config));
3867 // We need a route consisting of 3 paths:
3868 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3869 // To achieve this, the amount being transferred should be around
3870 // the total capacity of these 3 paths.
3872 // First, we set limits on these (previously unlimited) channels.
3873 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3875 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3876 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3877 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3878 short_channel_id: 1,
3881 cltv_expiry_delta: 0,
3882 htlc_minimum_msat: 0,
3883 htlc_maximum_msat: 100_000,
3885 fee_proportional_millionths: 0,
3886 excess_data: Vec::new()
3888 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3889 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3890 short_channel_id: 3,
3893 cltv_expiry_delta: 0,
3894 htlc_minimum_msat: 0,
3895 htlc_maximum_msat: 50_000,
3897 fee_proportional_millionths: 0,
3898 excess_data: Vec::new()
3901 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3902 // (total limit 60).
3903 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3904 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3905 short_channel_id: 12,
3908 cltv_expiry_delta: 0,
3909 htlc_minimum_msat: 0,
3910 htlc_maximum_msat: 60_000,
3912 fee_proportional_millionths: 0,
3913 excess_data: Vec::new()
3915 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3916 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3917 short_channel_id: 13,
3920 cltv_expiry_delta: 0,
3921 htlc_minimum_msat: 0,
3922 htlc_maximum_msat: 60_000,
3924 fee_proportional_millionths: 0,
3925 excess_data: Vec::new()
3928 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3929 // (total capacity 180 sats).
3930 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3931 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3932 short_channel_id: 2,
3935 cltv_expiry_delta: 0,
3936 htlc_minimum_msat: 0,
3937 htlc_maximum_msat: 200_000,
3939 fee_proportional_millionths: 0,
3940 excess_data: Vec::new()
3942 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3943 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3944 short_channel_id: 4,
3947 cltv_expiry_delta: 0,
3948 htlc_minimum_msat: 0,
3949 htlc_maximum_msat: 180_000,
3951 fee_proportional_millionths: 0,
3952 excess_data: Vec::new()
3956 // Attempt to route more than available results in a failure.
3957 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3958 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42,
3959 Arc::clone(&logger), &scorer, &random_seed_bytes) {
3960 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3961 } else { panic!(); }
3965 // Attempt to route while setting max_path_count to 0 results in a failure.
3966 let zero_payment_params = payment_params.clone().with_max_path_count(0);
3967 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3968 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100, 42,
3969 Arc::clone(&logger), &scorer, &random_seed_bytes) {
3970 assert_eq!(err, "Can't find a route with no paths allowed.");
3971 } else { panic!(); }
3975 // Attempt to route while setting max_path_count to 3 results in a failure.
3976 // This is the case because the minimal_value_contribution_msat would require each path
3977 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
3978 let fail_payment_params = payment_params.clone().with_max_path_count(3);
3979 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3980 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000, 42,
3981 Arc::clone(&logger), &scorer, &random_seed_bytes) {
3982 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3983 } else { panic!(); }
3987 // Now, attempt to route 250 sats (just a bit below the capacity).
3988 // Our algorithm should provide us with these 3 paths.
3989 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
3990 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3991 assert_eq!(route.paths.len(), 3);
3992 let mut total_amount_paid_msat = 0;
3993 for path in &route.paths {
3994 assert_eq!(path.len(), 2);
3995 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3996 total_amount_paid_msat += path.last().unwrap().fee_msat;
3998 assert_eq!(total_amount_paid_msat, 250_000);
4002 // Attempt to route an exact amount is also fine
4003 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4004 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4005 assert_eq!(route.paths.len(), 3);
4006 let mut total_amount_paid_msat = 0;
4007 for path in &route.paths {
4008 assert_eq!(path.len(), 2);
4009 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4010 total_amount_paid_msat += path.last().unwrap().fee_msat;
4012 assert_eq!(total_amount_paid_msat, 290_000);
4017 fn long_mpp_route_test() {
4018 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4019 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4020 let scorer = ln_test_utils::TestScorer::new();
4021 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4022 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4023 let config = UserConfig::default();
4024 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4026 // We need a route consisting of 3 paths:
4027 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4028 // Note that these paths overlap (channels 5, 12, 13).
4029 // We will route 300 sats.
4030 // Each path will have 100 sats capacity, those channels which
4031 // are used twice will have 200 sats capacity.
4033 // Disable other potential paths.
4034 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4036 short_channel_id: 2,
4039 cltv_expiry_delta: 0,
4040 htlc_minimum_msat: 0,
4041 htlc_maximum_msat: 100_000,
4043 fee_proportional_millionths: 0,
4044 excess_data: Vec::new()
4046 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4047 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4048 short_channel_id: 7,
4051 cltv_expiry_delta: 0,
4052 htlc_minimum_msat: 0,
4053 htlc_maximum_msat: 100_000,
4055 fee_proportional_millionths: 0,
4056 excess_data: Vec::new()
4059 // Path via {node0, node2} is channels {1, 3, 5}.
4060 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4061 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4062 short_channel_id: 1,
4065 cltv_expiry_delta: 0,
4066 htlc_minimum_msat: 0,
4067 htlc_maximum_msat: 100_000,
4069 fee_proportional_millionths: 0,
4070 excess_data: Vec::new()
4072 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4073 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4074 short_channel_id: 3,
4077 cltv_expiry_delta: 0,
4078 htlc_minimum_msat: 0,
4079 htlc_maximum_msat: 100_000,
4081 fee_proportional_millionths: 0,
4082 excess_data: Vec::new()
4085 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4086 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4087 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4088 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4089 short_channel_id: 5,
4092 cltv_expiry_delta: 0,
4093 htlc_minimum_msat: 0,
4094 htlc_maximum_msat: 200_000,
4096 fee_proportional_millionths: 0,
4097 excess_data: Vec::new()
4100 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4101 // Add 100 sats to the capacities of {12, 13}, because these channels
4102 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4103 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4104 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4105 short_channel_id: 12,
4108 cltv_expiry_delta: 0,
4109 htlc_minimum_msat: 0,
4110 htlc_maximum_msat: 200_000,
4112 fee_proportional_millionths: 0,
4113 excess_data: Vec::new()
4115 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4116 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4117 short_channel_id: 13,
4120 cltv_expiry_delta: 0,
4121 htlc_minimum_msat: 0,
4122 htlc_maximum_msat: 200_000,
4124 fee_proportional_millionths: 0,
4125 excess_data: Vec::new()
4128 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4129 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4130 short_channel_id: 6,
4133 cltv_expiry_delta: 0,
4134 htlc_minimum_msat: 0,
4135 htlc_maximum_msat: 100_000,
4137 fee_proportional_millionths: 0,
4138 excess_data: Vec::new()
4140 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4141 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4142 short_channel_id: 11,
4145 cltv_expiry_delta: 0,
4146 htlc_minimum_msat: 0,
4147 htlc_maximum_msat: 100_000,
4149 fee_proportional_millionths: 0,
4150 excess_data: Vec::new()
4153 // Path via {node7, node2} is channels {12, 13, 5}.
4154 // We already limited them to 200 sats (they are used twice for 100 sats).
4155 // Nothing to do here.
4158 // Attempt to route more than available results in a failure.
4159 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4160 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4161 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4162 } else { panic!(); }
4166 // Now, attempt to route 300 sats (exact amount we can route).
4167 // Our algorithm should provide us with these 3 paths, 100 sats each.
4168 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4169 assert_eq!(route.paths.len(), 3);
4171 let mut total_amount_paid_msat = 0;
4172 for path in &route.paths {
4173 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4174 total_amount_paid_msat += path.last().unwrap().fee_msat;
4176 assert_eq!(total_amount_paid_msat, 300_000);
4182 fn mpp_cheaper_route_test() {
4183 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4184 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4185 let scorer = ln_test_utils::TestScorer::new();
4186 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4187 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4188 let config = UserConfig::default();
4189 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4191 // This test checks that if we have two cheaper paths and one more expensive path,
4192 // so that liquidity-wise any 2 of 3 combination is sufficient,
4193 // two cheaper paths will be taken.
4194 // These paths have equal available liquidity.
4196 // We need a combination of 3 paths:
4197 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4198 // Note that these paths overlap (channels 5, 12, 13).
4199 // Each path will have 100 sats capacity, those channels which
4200 // are used twice will have 200 sats capacity.
4202 // Disable other potential paths.
4203 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4204 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4205 short_channel_id: 2,
4208 cltv_expiry_delta: 0,
4209 htlc_minimum_msat: 0,
4210 htlc_maximum_msat: 100_000,
4212 fee_proportional_millionths: 0,
4213 excess_data: Vec::new()
4215 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4216 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4217 short_channel_id: 7,
4220 cltv_expiry_delta: 0,
4221 htlc_minimum_msat: 0,
4222 htlc_maximum_msat: 100_000,
4224 fee_proportional_millionths: 0,
4225 excess_data: Vec::new()
4228 // Path via {node0, node2} is channels {1, 3, 5}.
4229 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4230 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4231 short_channel_id: 1,
4234 cltv_expiry_delta: 0,
4235 htlc_minimum_msat: 0,
4236 htlc_maximum_msat: 100_000,
4238 fee_proportional_millionths: 0,
4239 excess_data: Vec::new()
4241 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4242 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4243 short_channel_id: 3,
4246 cltv_expiry_delta: 0,
4247 htlc_minimum_msat: 0,
4248 htlc_maximum_msat: 100_000,
4250 fee_proportional_millionths: 0,
4251 excess_data: Vec::new()
4254 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4255 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4256 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4257 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4258 short_channel_id: 5,
4261 cltv_expiry_delta: 0,
4262 htlc_minimum_msat: 0,
4263 htlc_maximum_msat: 200_000,
4265 fee_proportional_millionths: 0,
4266 excess_data: Vec::new()
4269 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4270 // Add 100 sats to the capacities of {12, 13}, because these channels
4271 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4272 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4273 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4274 short_channel_id: 12,
4277 cltv_expiry_delta: 0,
4278 htlc_minimum_msat: 0,
4279 htlc_maximum_msat: 200_000,
4281 fee_proportional_millionths: 0,
4282 excess_data: Vec::new()
4284 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4285 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4286 short_channel_id: 13,
4289 cltv_expiry_delta: 0,
4290 htlc_minimum_msat: 0,
4291 htlc_maximum_msat: 200_000,
4293 fee_proportional_millionths: 0,
4294 excess_data: Vec::new()
4297 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4298 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4299 short_channel_id: 6,
4302 cltv_expiry_delta: 0,
4303 htlc_minimum_msat: 0,
4304 htlc_maximum_msat: 100_000,
4305 fee_base_msat: 1_000,
4306 fee_proportional_millionths: 0,
4307 excess_data: Vec::new()
4309 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4310 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4311 short_channel_id: 11,
4314 cltv_expiry_delta: 0,
4315 htlc_minimum_msat: 0,
4316 htlc_maximum_msat: 100_000,
4318 fee_proportional_millionths: 0,
4319 excess_data: Vec::new()
4322 // Path via {node7, node2} is channels {12, 13, 5}.
4323 // We already limited them to 200 sats (they are used twice for 100 sats).
4324 // Nothing to do here.
4327 // Now, attempt to route 180 sats.
4328 // Our algorithm should provide us with these 2 paths.
4329 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4330 assert_eq!(route.paths.len(), 2);
4332 let mut total_value_transferred_msat = 0;
4333 let mut total_paid_msat = 0;
4334 for path in &route.paths {
4335 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4336 total_value_transferred_msat += path.last().unwrap().fee_msat;
4338 total_paid_msat += hop.fee_msat;
4341 // If we paid fee, this would be higher.
4342 assert_eq!(total_value_transferred_msat, 180_000);
4343 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4344 assert_eq!(total_fees_paid, 0);
4349 fn fees_on_mpp_route_test() {
4350 // This test makes sure that MPP algorithm properly takes into account
4351 // fees charged on the channels, by making the fees impactful:
4352 // if the fee is not properly accounted for, the behavior is different.
4353 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4354 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4355 let scorer = ln_test_utils::TestScorer::new();
4356 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4357 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4358 let config = UserConfig::default();
4359 let payment_params = PaymentParameters::from_node_id(nodes[3], 42).with_features(channelmanager::provided_invoice_features(&config));
4361 // We need a route consisting of 2 paths:
4362 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4363 // We will route 200 sats, Each path will have 100 sats capacity.
4365 // This test is not particularly stable: e.g.,
4366 // there's a way to route via {node0, node2, node4}.
4367 // It works while pathfinding is deterministic, but can be broken otherwise.
4368 // It's fine to ignore this concern for now.
4370 // Disable other potential paths.
4371 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4372 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4373 short_channel_id: 2,
4376 cltv_expiry_delta: 0,
4377 htlc_minimum_msat: 0,
4378 htlc_maximum_msat: 100_000,
4380 fee_proportional_millionths: 0,
4381 excess_data: Vec::new()
4384 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4385 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4386 short_channel_id: 7,
4389 cltv_expiry_delta: 0,
4390 htlc_minimum_msat: 0,
4391 htlc_maximum_msat: 100_000,
4393 fee_proportional_millionths: 0,
4394 excess_data: Vec::new()
4397 // Path via {node0, node2} is channels {1, 3, 5}.
4398 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4399 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4400 short_channel_id: 1,
4403 cltv_expiry_delta: 0,
4404 htlc_minimum_msat: 0,
4405 htlc_maximum_msat: 100_000,
4407 fee_proportional_millionths: 0,
4408 excess_data: Vec::new()
4410 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4411 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4412 short_channel_id: 3,
4415 cltv_expiry_delta: 0,
4416 htlc_minimum_msat: 0,
4417 htlc_maximum_msat: 100_000,
4419 fee_proportional_millionths: 0,
4420 excess_data: Vec::new()
4423 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4424 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4425 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4426 short_channel_id: 5,
4429 cltv_expiry_delta: 0,
4430 htlc_minimum_msat: 0,
4431 htlc_maximum_msat: 100_000,
4433 fee_proportional_millionths: 0,
4434 excess_data: Vec::new()
4437 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4438 // All channels should be 100 sats capacity. But for the fee experiment,
4439 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4440 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4441 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4442 // so no matter how large are other channels,
4443 // the whole path will be limited by 100 sats with just these 2 conditions:
4444 // - channel 12 capacity is 250 sats
4445 // - fee for channel 6 is 150 sats
4446 // Let's test this by enforcing these 2 conditions and removing other limits.
4447 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4448 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4449 short_channel_id: 12,
4452 cltv_expiry_delta: 0,
4453 htlc_minimum_msat: 0,
4454 htlc_maximum_msat: 250_000,
4456 fee_proportional_millionths: 0,
4457 excess_data: Vec::new()
4459 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4460 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4461 short_channel_id: 13,
4464 cltv_expiry_delta: 0,
4465 htlc_minimum_msat: 0,
4466 htlc_maximum_msat: MAX_VALUE_MSAT,
4468 fee_proportional_millionths: 0,
4469 excess_data: Vec::new()
4472 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4473 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4474 short_channel_id: 6,
4477 cltv_expiry_delta: 0,
4478 htlc_minimum_msat: 0,
4479 htlc_maximum_msat: MAX_VALUE_MSAT,
4480 fee_base_msat: 150_000,
4481 fee_proportional_millionths: 0,
4482 excess_data: Vec::new()
4484 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4485 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4486 short_channel_id: 11,
4489 cltv_expiry_delta: 0,
4490 htlc_minimum_msat: 0,
4491 htlc_maximum_msat: MAX_VALUE_MSAT,
4493 fee_proportional_millionths: 0,
4494 excess_data: Vec::new()
4498 // Attempt to route more than available results in a failure.
4499 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4500 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4501 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4502 } else { panic!(); }
4506 // Now, attempt to route 200 sats (exact amount we can route).
4507 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4508 assert_eq!(route.paths.len(), 2);
4510 let mut total_amount_paid_msat = 0;
4511 for path in &route.paths {
4512 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4513 total_amount_paid_msat += path.last().unwrap().fee_msat;
4515 assert_eq!(total_amount_paid_msat, 200_000);
4516 assert_eq!(route.get_total_fees(), 150_000);
4521 fn mpp_with_last_hops() {
4522 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4523 // via a single last-hop route hint, we'd fail to route if we first collected routes
4524 // totaling close but not quite enough to fund the full payment.
4526 // This was because we considered last-hop hints to have exactly the sought payment amount
4527 // instead of the amount we were trying to collect, needlessly limiting our path searching
4528 // at the very first hop.
4530 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4531 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4532 // to only have the remaining to-collect amount in available liquidity.
4534 // This bug appeared in production in some specific channel configurations.
4535 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4536 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4537 let scorer = ln_test_utils::TestScorer::new();
4538 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4539 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4540 let config = UserConfig::default();
4541 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap(), 42).with_features(channelmanager::provided_invoice_features(&config))
4542 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4543 src_node_id: nodes[2],
4544 short_channel_id: 42,
4545 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4546 cltv_expiry_delta: 42,
4547 htlc_minimum_msat: None,
4548 htlc_maximum_msat: None,
4549 }])]).with_max_channel_saturation_power_of_half(0);
4551 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4552 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4553 // would first use the no-fee route and then fail to find a path along the second route as
4554 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4555 // under 5% of our payment amount.
4556 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4557 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4558 short_channel_id: 1,
4561 cltv_expiry_delta: (5 << 4) | 5,
4562 htlc_minimum_msat: 0,
4563 htlc_maximum_msat: 99_000,
4564 fee_base_msat: u32::max_value(),
4565 fee_proportional_millionths: u32::max_value(),
4566 excess_data: Vec::new()
4568 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4569 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4570 short_channel_id: 2,
4573 cltv_expiry_delta: (5 << 4) | 3,
4574 htlc_minimum_msat: 0,
4575 htlc_maximum_msat: 99_000,
4576 fee_base_msat: u32::max_value(),
4577 fee_proportional_millionths: u32::max_value(),
4578 excess_data: Vec::new()
4580 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4581 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4582 short_channel_id: 4,
4585 cltv_expiry_delta: (4 << 4) | 1,
4586 htlc_minimum_msat: 0,
4587 htlc_maximum_msat: MAX_VALUE_MSAT,
4589 fee_proportional_millionths: 0,
4590 excess_data: Vec::new()
4592 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4593 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4594 short_channel_id: 13,
4596 flags: 0|2, // Channel disabled
4597 cltv_expiry_delta: (13 << 4) | 1,
4598 htlc_minimum_msat: 0,
4599 htlc_maximum_msat: MAX_VALUE_MSAT,
4601 fee_proportional_millionths: 2000000,
4602 excess_data: Vec::new()
4605 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4607 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();
4608 assert_eq!(route.paths.len(), 2);
4609 route.paths.sort_by_key(|path| path[0].short_channel_id);
4610 // Paths are manually ordered ordered by SCID, so:
4611 // * the first is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4612 // * the second is channel 2 (1 msat fee) -> channel 4 -> channel 42
4613 assert_eq!(route.paths[0][0].short_channel_id, 1);
4614 assert_eq!(route.paths[0][0].fee_msat, 0);
4615 assert_eq!(route.paths[0][2].fee_msat, 99_000);
4616 assert_eq!(route.paths[1][0].short_channel_id, 2);
4617 assert_eq!(route.paths[1][0].fee_msat, 1);
4618 assert_eq!(route.paths[1][2].fee_msat, 1_000);
4619 assert_eq!(route.get_total_fees(), 1);
4620 assert_eq!(route.get_total_amount(), 100_000);
4624 fn drop_lowest_channel_mpp_route_test() {
4625 // This test checks that low-capacity channel is dropped when after
4626 // path finding we realize that we found more capacity than we need.
4627 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4628 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4629 let scorer = ln_test_utils::TestScorer::new();
4630 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4631 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4632 let config = UserConfig::default();
4633 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config))
4634 .with_max_channel_saturation_power_of_half(0);
4636 // We need a route consisting of 3 paths:
4637 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4639 // The first and the second paths should be sufficient, but the third should be
4640 // cheaper, so that we select it but drop later.
4642 // First, we set limits on these (previously unlimited) channels.
4643 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4645 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4646 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4647 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4648 short_channel_id: 1,
4651 cltv_expiry_delta: 0,
4652 htlc_minimum_msat: 0,
4653 htlc_maximum_msat: 100_000,
4655 fee_proportional_millionths: 0,
4656 excess_data: Vec::new()
4658 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4660 short_channel_id: 3,
4663 cltv_expiry_delta: 0,
4664 htlc_minimum_msat: 0,
4665 htlc_maximum_msat: 50_000,
4667 fee_proportional_millionths: 0,
4668 excess_data: Vec::new()
4671 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4672 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4673 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4674 short_channel_id: 12,
4677 cltv_expiry_delta: 0,
4678 htlc_minimum_msat: 0,
4679 htlc_maximum_msat: 60_000,
4681 fee_proportional_millionths: 0,
4682 excess_data: Vec::new()
4684 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4685 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4686 short_channel_id: 13,
4689 cltv_expiry_delta: 0,
4690 htlc_minimum_msat: 0,
4691 htlc_maximum_msat: 60_000,
4693 fee_proportional_millionths: 0,
4694 excess_data: Vec::new()
4697 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4698 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4699 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4700 short_channel_id: 2,
4703 cltv_expiry_delta: 0,
4704 htlc_minimum_msat: 0,
4705 htlc_maximum_msat: 20_000,
4707 fee_proportional_millionths: 0,
4708 excess_data: Vec::new()
4710 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4711 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4712 short_channel_id: 4,
4715 cltv_expiry_delta: 0,
4716 htlc_minimum_msat: 0,
4717 htlc_maximum_msat: 20_000,
4719 fee_proportional_millionths: 0,
4720 excess_data: Vec::new()
4724 // Attempt to route more than available results in a failure.
4725 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4726 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4727 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4728 } else { panic!(); }
4732 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4733 // Our algorithm should provide us with these 3 paths.
4734 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4735 assert_eq!(route.paths.len(), 3);
4736 let mut total_amount_paid_msat = 0;
4737 for path in &route.paths {
4738 assert_eq!(path.len(), 2);
4739 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4740 total_amount_paid_msat += path.last().unwrap().fee_msat;
4742 assert_eq!(total_amount_paid_msat, 125_000);
4746 // Attempt to route without the last small cheap channel
4747 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4748 assert_eq!(route.paths.len(), 2);
4749 let mut total_amount_paid_msat = 0;
4750 for path in &route.paths {
4751 assert_eq!(path.len(), 2);
4752 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4753 total_amount_paid_msat += path.last().unwrap().fee_msat;
4755 assert_eq!(total_amount_paid_msat, 90_000);
4760 fn min_criteria_consistency() {
4761 // Test that we don't use an inconsistent metric between updating and walking nodes during
4762 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4763 // was updated with a different criterion from the heap sorting, resulting in loops in
4764 // calculated paths. We test for that specific case here.
4766 // We construct a network that looks like this:
4768 // node2 -1(3)2- node3
4772 // node1 -1(5)2- node4 -1(1)2- node6
4778 // We create a loop on the side of our real path - our destination is node 6, with a
4779 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4780 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4781 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4782 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4783 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4784 // "previous hop" being set to node 3, creating a loop in the path.
4785 let secp_ctx = Secp256k1::new();
4786 let logger = Arc::new(ln_test_utils::TestLogger::new());
4787 let network = Arc::new(NetworkGraph::new(Network::Testnet, Arc::clone(&logger)));
4788 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
4789 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4790 let scorer = ln_test_utils::TestScorer::new();
4791 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4792 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4793 let payment_params = PaymentParameters::from_node_id(nodes[6], 42);
4795 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4796 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4797 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4798 short_channel_id: 6,
4801 cltv_expiry_delta: (6 << 4) | 0,
4802 htlc_minimum_msat: 0,
4803 htlc_maximum_msat: MAX_VALUE_MSAT,
4805 fee_proportional_millionths: 0,
4806 excess_data: Vec::new()
4808 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4810 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4811 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4812 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4813 short_channel_id: 5,
4816 cltv_expiry_delta: (5 << 4) | 0,
4817 htlc_minimum_msat: 0,
4818 htlc_maximum_msat: MAX_VALUE_MSAT,
4820 fee_proportional_millionths: 0,
4821 excess_data: Vec::new()
4823 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4825 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4826 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4827 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4828 short_channel_id: 4,
4831 cltv_expiry_delta: (4 << 4) | 0,
4832 htlc_minimum_msat: 0,
4833 htlc_maximum_msat: MAX_VALUE_MSAT,
4835 fee_proportional_millionths: 0,
4836 excess_data: Vec::new()
4838 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4840 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4841 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4842 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4843 short_channel_id: 3,
4846 cltv_expiry_delta: (3 << 4) | 0,
4847 htlc_minimum_msat: 0,
4848 htlc_maximum_msat: MAX_VALUE_MSAT,
4850 fee_proportional_millionths: 0,
4851 excess_data: Vec::new()
4853 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4855 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4856 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4857 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4858 short_channel_id: 2,
4861 cltv_expiry_delta: (2 << 4) | 0,
4862 htlc_minimum_msat: 0,
4863 htlc_maximum_msat: MAX_VALUE_MSAT,
4865 fee_proportional_millionths: 0,
4866 excess_data: Vec::new()
4869 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4870 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4871 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4872 short_channel_id: 1,
4875 cltv_expiry_delta: (1 << 4) | 0,
4876 htlc_minimum_msat: 100,
4877 htlc_maximum_msat: MAX_VALUE_MSAT,
4879 fee_proportional_millionths: 0,
4880 excess_data: Vec::new()
4882 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4885 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4886 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4887 assert_eq!(route.paths.len(), 1);
4888 assert_eq!(route.paths[0].len(), 3);
4890 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4891 assert_eq!(route.paths[0][0].short_channel_id, 6);
4892 assert_eq!(route.paths[0][0].fee_msat, 100);
4893 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
4894 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4895 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4897 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4898 assert_eq!(route.paths[0][1].short_channel_id, 5);
4899 assert_eq!(route.paths[0][1].fee_msat, 0);
4900 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
4901 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4902 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4904 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4905 assert_eq!(route.paths[0][2].short_channel_id, 1);
4906 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4907 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4908 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4909 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4915 fn exact_fee_liquidity_limit() {
4916 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4917 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4918 // we calculated fees on a higher value, resulting in us ignoring such paths.
4919 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4920 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4921 let scorer = ln_test_utils::TestScorer::new();
4922 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4923 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4924 let payment_params = PaymentParameters::from_node_id(nodes[2], 42);
4926 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4928 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4929 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4930 short_channel_id: 2,
4933 cltv_expiry_delta: 0,
4934 htlc_minimum_msat: 0,
4935 htlc_maximum_msat: 85_000,
4937 fee_proportional_millionths: 0,
4938 excess_data: Vec::new()
4941 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4942 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4943 short_channel_id: 12,
4946 cltv_expiry_delta: (4 << 4) | 1,
4947 htlc_minimum_msat: 0,
4948 htlc_maximum_msat: 270_000,
4950 fee_proportional_millionths: 1000000,
4951 excess_data: Vec::new()
4955 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4956 // 200% fee charged channel 13 in the 1-to-2 direction.
4957 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4958 assert_eq!(route.paths.len(), 1);
4959 assert_eq!(route.paths[0].len(), 2);
4961 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4962 assert_eq!(route.paths[0][0].short_channel_id, 12);
4963 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4964 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4965 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4966 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4968 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4969 assert_eq!(route.paths[0][1].short_channel_id, 13);
4970 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4971 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4972 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4973 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4978 fn htlc_max_reduction_below_min() {
4979 // Test that if, while walking the graph, we reduce the value being sent to meet an
4980 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4981 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4982 // resulting in us thinking there is no possible path, even if other paths exist.
4983 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4984 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4985 let scorer = ln_test_utils::TestScorer::new();
4986 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4987 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4988 let config = UserConfig::default();
4989 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
4991 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4992 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4993 // then try to send 90_000.
4994 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4996 short_channel_id: 2,
4999 cltv_expiry_delta: 0,
5000 htlc_minimum_msat: 0,
5001 htlc_maximum_msat: 80_000,
5003 fee_proportional_millionths: 0,
5004 excess_data: Vec::new()
5006 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5008 short_channel_id: 4,
5011 cltv_expiry_delta: (4 << 4) | 1,
5012 htlc_minimum_msat: 90_000,
5013 htlc_maximum_msat: MAX_VALUE_MSAT,
5015 fee_proportional_millionths: 0,
5016 excess_data: Vec::new()
5020 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5021 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5022 // expensive) channels 12-13 path.
5023 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5024 assert_eq!(route.paths.len(), 1);
5025 assert_eq!(route.paths[0].len(), 2);
5027 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5028 assert_eq!(route.paths[0][0].short_channel_id, 12);
5029 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5030 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5031 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5032 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5034 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5035 assert_eq!(route.paths[0][1].short_channel_id, 13);
5036 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5037 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5038 assert_eq!(route.paths[0][1].node_features.le_flags(), channelmanager::provided_invoice_features(&config).le_flags());
5039 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5044 fn multiple_direct_first_hops() {
5045 // Previously we'd only ever considered one first hop path per counterparty.
5046 // However, as we don't restrict users to one channel per peer, we really need to support
5047 // looking at all first hop paths.
5048 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5049 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5050 // route over multiple channels with the same first hop.
5051 let secp_ctx = Secp256k1::new();
5052 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5053 let logger = Arc::new(ln_test_utils::TestLogger::new());
5054 let network_graph = NetworkGraph::new(Network::Testnet, Arc::clone(&logger));
5055 let scorer = ln_test_utils::TestScorer::new();
5056 let config = UserConfig::default();
5057 let payment_params = PaymentParameters::from_node_id(nodes[0], 42).with_features(channelmanager::provided_invoice_features(&config));
5058 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5059 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5062 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5063 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 200_000),
5064 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 10_000),
5065 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5066 assert_eq!(route.paths.len(), 1);
5067 assert_eq!(route.paths[0].len(), 1);
5069 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5070 assert_eq!(route.paths[0][0].short_channel_id, 3);
5071 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5074 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5075 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5076 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5077 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5078 assert_eq!(route.paths.len(), 2);
5079 assert_eq!(route.paths[0].len(), 1);
5080 assert_eq!(route.paths[1].len(), 1);
5082 assert!((route.paths[0][0].short_channel_id == 3 && route.paths[1][0].short_channel_id == 2) ||
5083 (route.paths[0][0].short_channel_id == 2 && route.paths[1][0].short_channel_id == 3));
5085 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5086 assert_eq!(route.paths[0][0].fee_msat, 50_000);
5088 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
5089 assert_eq!(route.paths[1][0].fee_msat, 50_000);
5093 // If we have a bunch of outbound channels to the same node, where most are not
5094 // sufficient to pay the full payment, but one is, we should default to just using the
5095 // one single channel that has sufficient balance, avoiding MPP.
5097 // If we have several options above the 3xpayment value threshold, we should pick the
5098 // smallest of them, avoiding further fragmenting our available outbound balance to
5100 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5101 &get_channel_details(Some(2), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5102 &get_channel_details(Some(3), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5103 &get_channel_details(Some(5), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5104 &get_channel_details(Some(6), nodes[0], channelmanager::provided_init_features(&config), 300_000),
5105 &get_channel_details(Some(7), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5106 &get_channel_details(Some(8), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5107 &get_channel_details(Some(9), nodes[0], channelmanager::provided_init_features(&config), 50_000),
5108 &get_channel_details(Some(4), nodes[0], channelmanager::provided_init_features(&config), 1_000_000),
5109 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5110 assert_eq!(route.paths.len(), 1);
5111 assert_eq!(route.paths[0].len(), 1);
5113 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5114 assert_eq!(route.paths[0][0].short_channel_id, 6);
5115 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5120 fn prefers_shorter_route_with_higher_fees() {
5121 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5122 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5123 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5125 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5126 let scorer = ln_test_utils::TestScorer::new();
5127 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5128 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5129 let route = get_route(
5130 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5131 Arc::clone(&logger), &scorer, &random_seed_bytes
5133 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5135 assert_eq!(route.get_total_fees(), 100);
5136 assert_eq!(route.get_total_amount(), 100);
5137 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5139 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5140 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5141 let scorer = FixedPenaltyScorer::with_penalty(100);
5142 let route = get_route(
5143 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5144 Arc::clone(&logger), &scorer, &random_seed_bytes
5146 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5148 assert_eq!(route.get_total_fees(), 300);
5149 assert_eq!(route.get_total_amount(), 100);
5150 assert_eq!(path, vec![2, 4, 7, 10]);
5153 struct BadChannelScorer {
5154 short_channel_id: u64,
5158 impl Writeable for BadChannelScorer {
5159 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5161 impl Score for BadChannelScorer {
5162 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage) -> u64 {
5163 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5166 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5167 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5168 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5169 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
5172 struct BadNodeScorer {
5177 impl Writeable for BadNodeScorer {
5178 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), crate::io::Error> { unimplemented!() }
5181 impl Score for BadNodeScorer {
5182 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage) -> u64 {
5183 if *target == self.node_id { u64::max_value() } else { 0 }
5186 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5187 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5188 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5189 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
5193 fn avoids_routing_through_bad_channels_and_nodes() {
5194 let (secp_ctx, network, _, _, logger) = build_graph();
5195 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5196 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5197 let network_graph = network.read_only();
5199 // A path to nodes[6] exists when no penalties are applied to any channel.
5200 let scorer = ln_test_utils::TestScorer::new();
5201 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5202 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5203 let route = get_route(
5204 &our_id, &payment_params, &network_graph, None, 100, 42,
5205 Arc::clone(&logger), &scorer, &random_seed_bytes
5207 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5209 assert_eq!(route.get_total_fees(), 100);
5210 assert_eq!(route.get_total_amount(), 100);
5211 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5213 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5214 let scorer = BadChannelScorer { short_channel_id: 6 };
5215 let route = get_route(
5216 &our_id, &payment_params, &network_graph, None, 100, 42,
5217 Arc::clone(&logger), &scorer, &random_seed_bytes
5219 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5221 assert_eq!(route.get_total_fees(), 300);
5222 assert_eq!(route.get_total_amount(), 100);
5223 assert_eq!(path, vec![2, 4, 7, 10]);
5225 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5226 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5228 &our_id, &payment_params, &network_graph, None, 100, 42,
5229 Arc::clone(&logger), &scorer, &random_seed_bytes
5231 Err(LightningError { err, .. } ) => {
5232 assert_eq!(err, "Failed to find a path to the given destination");
5234 Ok(_) => panic!("Expected error"),
5239 fn total_fees_single_path() {
5243 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5244 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5245 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5248 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5249 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5250 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5253 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5254 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5255 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5258 payment_params: None,
5261 assert_eq!(route.get_total_fees(), 250);
5262 assert_eq!(route.get_total_amount(), 225);
5266 fn total_fees_multi_path() {
5270 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5271 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5272 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5275 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5276 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5277 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5281 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5282 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5283 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5286 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5287 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5288 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5291 payment_params: None,
5294 assert_eq!(route.get_total_fees(), 200);
5295 assert_eq!(route.get_total_amount(), 300);
5299 fn total_empty_route_no_panic() {
5300 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5301 // would both panic if the route was completely empty. We test to ensure they return 0
5302 // here, even though its somewhat nonsensical as a route.
5303 let route = Route { paths: Vec::new(), payment_params: None };
5305 assert_eq!(route.get_total_fees(), 0);
5306 assert_eq!(route.get_total_amount(), 0);
5310 fn limits_total_cltv_delta() {
5311 let (secp_ctx, network, _, _, logger) = build_graph();
5312 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5313 let network_graph = network.read_only();
5315 let scorer = ln_test_utils::TestScorer::new();
5317 // Make sure that generally there is at least one route available
5318 let feasible_max_total_cltv_delta = 1008;
5319 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5320 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5321 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5322 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5323 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5324 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5325 assert_ne!(path.len(), 0);
5327 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5328 let fail_max_total_cltv_delta = 23;
5329 let fail_payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5330 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5331 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5333 Err(LightningError { err, .. } ) => {
5334 assert_eq!(err, "Failed to find a path to the given destination");
5336 Ok(_) => panic!("Expected error"),
5341 fn avoids_recently_failed_paths() {
5342 // Ensure that the router always avoids all of the `previously_failed_channels` channels by
5343 // randomly inserting channels into it until we can't find a route anymore.
5344 let (secp_ctx, network, _, _, logger) = build_graph();
5345 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5346 let network_graph = network.read_only();
5348 let scorer = ln_test_utils::TestScorer::new();
5349 let mut payment_params = PaymentParameters::from_node_id(nodes[6], 0).with_route_hints(last_hops(&nodes))
5350 .with_max_path_count(1);
5351 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5352 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5354 // We should be able to find a route initially, and then after we fail a few random
5355 // channels eventually we won't be able to any longer.
5356 assert!(get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).is_ok());
5358 if let Ok(route) = get_route(&our_id, &payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes) {
5359 for chan in route.paths[0].iter() {
5360 assert!(!payment_params.previously_failed_channels.contains(&chan.short_channel_id));
5362 let victim = (u64::from_ne_bytes(random_seed_bytes[0..8].try_into().unwrap()) as usize)
5363 % route.paths[0].len();
5364 payment_params.previously_failed_channels.push(route.paths[0][victim].short_channel_id);
5370 fn limits_path_length() {
5371 let (secp_ctx, network, _, _, logger) = build_line_graph();
5372 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5373 let network_graph = network.read_only();
5375 let scorer = ln_test_utils::TestScorer::new();
5376 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5377 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5379 // First check we can actually create a long route on this graph.
5380 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18], 0);
5381 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0,
5382 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5383 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5384 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5386 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5387 let fail_payment_params = PaymentParameters::from_node_id(nodes[19], 0);
5388 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0,
5389 Arc::clone(&logger), &scorer, &random_seed_bytes)
5391 Err(LightningError { err, .. } ) => {
5392 assert_eq!(err, "Failed to find a path to the given destination");
5394 Ok(_) => panic!("Expected error"),
5399 fn adds_and_limits_cltv_offset() {
5400 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5401 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5403 let scorer = ln_test_utils::TestScorer::new();
5405 let payment_params = PaymentParameters::from_node_id(nodes[6], 42).with_route_hints(last_hops(&nodes));
5406 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5407 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5408 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5409 assert_eq!(route.paths.len(), 1);
5411 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5413 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5414 let mut route_default = route.clone();
5415 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5416 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5417 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5418 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5419 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5421 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5422 let mut route_limited = route.clone();
5423 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5424 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5425 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5426 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5427 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5431 fn adds_plausible_cltv_offset() {
5432 let (secp_ctx, network, _, _, logger) = build_graph();
5433 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5434 let network_graph = network.read_only();
5435 let network_nodes = network_graph.nodes();
5436 let network_channels = network_graph.channels();
5437 let scorer = ln_test_utils::TestScorer::new();
5438 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5439 let keys_manager = ln_test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5440 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5442 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5443 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5444 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5446 let mut path_plausibility = vec![];
5448 for p in route.paths {
5449 // 1. Select random observation point
5450 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5451 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5453 prng.process_in_place(&mut random_bytes);
5454 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5455 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5457 // 2. Calculate what CLTV expiry delta we would observe there
5458 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5460 // 3. Starting from the observation point, find candidate paths
5461 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5462 candidates.push_back((observation_point, vec![]));
5464 let mut found_plausible_candidate = false;
5466 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5467 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5468 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5469 found_plausible_candidate = true;
5470 break 'candidate_loop;
5474 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5475 for channel_id in &cur_node.channels {
5476 if let Some(channel_info) = network_channels.get(&channel_id) {
5477 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5478 let next_cltv_expiry_delta = dir_info.direction().cltv_expiry_delta as u32;
5479 if cur_path_cltv_deltas.iter().sum::<u32>()
5480 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5481 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5482 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5483 candidates.push_back((*next_id, new_path_cltv_deltas));
5491 path_plausibility.push(found_plausible_candidate);
5493 assert!(path_plausibility.iter().all(|x| *x));
5497 fn builds_correct_path_from_hops() {
5498 let (secp_ctx, network, _, _, logger) = build_graph();
5499 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5500 let network_graph = network.read_only();
5502 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5503 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5505 let payment_params = PaymentParameters::from_node_id(nodes[3], 0);
5506 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5507 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5508 &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
5509 let route_hop_pubkeys = route.paths[0].iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5510 assert_eq!(hops.len(), route.paths[0].len());
5511 for (idx, hop_pubkey) in hops.iter().enumerate() {
5512 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5517 fn avoids_saturating_channels() {
5518 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5519 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5521 let scorer = ProbabilisticScorer::new(Default::default(), &*network_graph, Arc::clone(&logger));
5523 // Set the fee on channel 13 to 100% to match channel 4 giving us two equivalent paths (us
5524 // -> node 7 -> node2 and us -> node 1 -> node 2) which we should balance over.
5525 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5526 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5527 short_channel_id: 4,
5530 cltv_expiry_delta: (4 << 4) | 1,
5531 htlc_minimum_msat: 0,
5532 htlc_maximum_msat: 250_000_000,
5534 fee_proportional_millionths: 0,
5535 excess_data: Vec::new()
5537 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
5538 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5539 short_channel_id: 13,
5542 cltv_expiry_delta: (13 << 4) | 1,
5543 htlc_minimum_msat: 0,
5544 htlc_maximum_msat: 250_000_000,
5546 fee_proportional_millionths: 0,
5547 excess_data: Vec::new()
5550 let config = UserConfig::default();
5551 let payment_params = PaymentParameters::from_node_id(nodes[2], 42).with_features(channelmanager::provided_invoice_features(&config));
5552 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5553 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5554 // 100,000 sats is less than the available liquidity on each channel, set above.
5555 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();
5556 assert_eq!(route.paths.len(), 2);
5557 assert!((route.paths[0][1].short_channel_id == 4 && route.paths[1][1].short_channel_id == 13) ||
5558 (route.paths[1][1].short_channel_id == 4 && route.paths[0][1].short_channel_id == 13));
5561 #[cfg(not(feature = "no-std"))]
5562 pub(super) fn random_init_seed() -> u64 {
5563 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5564 use core::hash::{BuildHasher, Hasher};
5565 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5566 println!("Using seed of {}", seed);
5569 #[cfg(not(feature = "no-std"))]
5570 use crate::util::ser::ReadableArgs;
5573 #[cfg(not(feature = "no-std"))]
5574 fn generate_routes() {
5575 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5577 let mut d = match super::bench_utils::get_route_file() {
5584 let logger = ln_test_utils::TestLogger::new();
5585 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5586 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5587 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5589 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5590 let mut seed = random_init_seed() as usize;
5591 let nodes = graph.read_only().nodes().clone();
5592 'load_endpoints: for _ in 0..10 {
5594 seed = seed.overflowing_mul(0xdeadbeef).0;
5595 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5596 seed = seed.overflowing_mul(0xdeadbeef).0;
5597 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5598 let payment_params = PaymentParameters::from_node_id(dst, 42);
5599 let amt = seed as u64 % 200_000_000;
5600 let params = ProbabilisticScoringParameters::default();
5601 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5602 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5603 continue 'load_endpoints;
5610 #[cfg(not(feature = "no-std"))]
5611 fn generate_routes_mpp() {
5612 use crate::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5614 let mut d = match super::bench_utils::get_route_file() {
5621 let logger = ln_test_utils::TestLogger::new();
5622 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5623 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5624 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5625 let config = UserConfig::default();
5627 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5628 let mut seed = random_init_seed() as usize;
5629 let nodes = graph.read_only().nodes().clone();
5630 'load_endpoints: for _ in 0..10 {
5632 seed = seed.overflowing_mul(0xdeadbeef).0;
5633 let src = &PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5634 seed = seed.overflowing_mul(0xdeadbeef).0;
5635 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5636 let payment_params = PaymentParameters::from_node_id(dst, 42).with_features(channelmanager::provided_invoice_features(&config));
5637 let amt = seed as u64 % 200_000_000;
5638 let params = ProbabilisticScoringParameters::default();
5639 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5640 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5641 continue 'load_endpoints;
5648 fn honors_manual_penalties() {
5649 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
5650 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5652 let keys_manager = ln_test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5653 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5655 let scorer_params = ProbabilisticScoringParameters::default();
5656 let mut scorer = ProbabilisticScorer::new(scorer_params, Arc::clone(&network_graph), Arc::clone(&logger));
5658 // First check set manual penalties are returned by the scorer.
5659 let usage = ChannelUsage {
5661 inflight_htlc_msat: 0,
5662 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: 1_000 },
5664 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
5665 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
5666 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage), 456);
5668 // Then check we can get a normal route
5669 let payment_params = PaymentParameters::from_node_id(nodes[10], 42);
5670 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5671 assert!(route.is_ok());
5673 // Then check that we can't get a route if we ban an intermediate node.
5674 scorer.add_banned(&NodeId::from_pubkey(&nodes[3]));
5675 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5676 assert!(route.is_err());
5678 // Finally make sure we can route again, when we remove the ban.
5679 scorer.remove_banned(&NodeId::from_pubkey(&nodes[3]));
5680 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5681 assert!(route.is_ok());
5685 #[cfg(all(test, not(feature = "no-std")))]
5686 pub(crate) mod bench_utils {
5688 /// Tries to open a network graph file, or panics with a URL to fetch it.
5689 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5690 let res = File::open("net_graph-2023-01-18.bin") // By default we're run in RL/lightning
5691 .or_else(|_| File::open("lightning/net_graph-2023-01-18.bin")) // We may be run manually in RL/
5692 .or_else(|_| { // Fall back to guessing based on the binary location
5693 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5694 let mut path = std::env::current_exe().unwrap();
5695 path.pop(); // lightning-...
5697 path.pop(); // debug
5698 path.pop(); // target
5699 path.push("lightning");
5700 path.push("net_graph-2023-01-18.bin");
5701 eprintln!("{}", path.to_str().unwrap());
5704 .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");
5705 #[cfg(require_route_graph_test)]
5706 return Ok(res.unwrap());
5707 #[cfg(not(require_route_graph_test))]
5712 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5715 use bitcoin::hashes::Hash;
5716 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5717 use crate::chain::transaction::OutPoint;
5718 use crate::chain::keysinterface::{EntropySource, KeysManager};
5719 use crate::ln::channelmanager::{self, ChannelCounterparty, ChannelDetails};
5720 use crate::ln::features::InvoiceFeatures;
5721 use crate::routing::gossip::NetworkGraph;
5722 use crate::routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters};
5723 use crate::util::config::UserConfig;
5724 use crate::util::logger::{Logger, Record};
5725 use crate::util::ser::ReadableArgs;
5729 struct DummyLogger {}
5730 impl Logger for DummyLogger {
5731 fn log(&self, _record: &Record) {}
5734 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
5735 let mut d = bench_utils::get_route_file().unwrap();
5736 NetworkGraph::read(&mut d, logger).unwrap()
5739 fn payer_pubkey() -> PublicKey {
5740 let secp_ctx = Secp256k1::new();
5741 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5745 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5747 channel_id: [0; 32],
5748 counterparty: ChannelCounterparty {
5749 features: channelmanager::provided_init_features(&UserConfig::default()),
5751 unspendable_punishment_reserve: 0,
5752 forwarding_info: None,
5753 outbound_htlc_minimum_msat: None,
5754 outbound_htlc_maximum_msat: None,
5756 funding_txo: Some(OutPoint {
5757 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5760 short_channel_id: Some(1),
5761 inbound_scid_alias: None,
5762 outbound_scid_alias: None,
5763 channel_value_satoshis: 10_000_000,
5765 balance_msat: 10_000_000,
5766 outbound_capacity_msat: 10_000_000,
5767 next_outbound_htlc_limit_msat: 10_000_000,
5768 inbound_capacity_msat: 0,
5769 unspendable_punishment_reserve: None,
5770 confirmations_required: None,
5771 confirmations: None,
5772 force_close_spend_delay: None,
5774 is_channel_ready: true,
5777 inbound_htlc_minimum_msat: None,
5778 inbound_htlc_maximum_msat: None,
5780 feerate_sat_per_1000_weight: None,
5785 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5786 let logger = DummyLogger {};
5787 let network_graph = read_network_graph(&logger);
5788 let scorer = FixedPenaltyScorer::with_penalty(0);
5789 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5793 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5794 let logger = DummyLogger {};
5795 let network_graph = read_network_graph(&logger);
5796 let scorer = FixedPenaltyScorer::with_penalty(0);
5797 generate_routes(bench, &network_graph, scorer, channelmanager::provided_invoice_features(&UserConfig::default()));
5801 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5802 let logger = DummyLogger {};
5803 let network_graph = read_network_graph(&logger);
5804 let params = ProbabilisticScoringParameters::default();
5805 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5806 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5810 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5811 let logger = DummyLogger {};
5812 let network_graph = read_network_graph(&logger);
5813 let params = ProbabilisticScoringParameters::default();
5814 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5815 generate_routes(bench, &network_graph, scorer, channelmanager::provided_invoice_features(&UserConfig::default()));
5818 fn generate_routes<S: Score>(
5819 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S,
5820 features: InvoiceFeatures
5822 let nodes = graph.read_only().nodes().clone();
5823 let payer = payer_pubkey();
5824 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5825 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5827 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5828 let mut routes = Vec::new();
5829 let mut route_endpoints = Vec::new();
5830 let mut seed: usize = 0xdeadbeef;
5831 'load_endpoints: for _ in 0..150 {
5834 let src = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5836 let dst = PublicKey::from_slice(nodes.unordered_keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5837 let params = PaymentParameters::from_node_id(dst, 42).with_features(features.clone());
5838 let first_hop = first_hop(src);
5839 let amt = seed as u64 % 1_000_000;
5840 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5842 route_endpoints.push((first_hop, params, amt));
5843 continue 'load_endpoints;
5848 // ...and seed the scorer with success and failure data...
5849 for route in routes {
5850 let amount = route.get_total_amount();
5851 if amount < 250_000 {
5852 for path in route.paths {
5853 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5855 } else if amount > 750_000 {
5856 for path in route.paths {
5857 let short_channel_id = path[path.len() / 2].short_channel_id;
5858 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5863 // Because we've changed channel scores, its possible we'll take different routes to the
5864 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5865 // requires a too-high CLTV delta.
5866 route_endpoints.retain(|(first_hop, params, amt)| {
5867 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5869 route_endpoints.truncate(100);
5870 assert_eq!(route_endpoints.len(), 100);
5872 // ...then benchmark finding paths between the nodes we learned.
5875 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5876 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());