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 top-level routing/network map tracking logic lives here.
12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::scoring::Score;
21 use routing::network_graph::{DirectedChannelInfoWithUpdate, EffectiveCapacity, NetworkGraph, ReadOnlyNetworkGraph, NodeId, RoutingFees};
22 use util::ser::{Writeable, Readable};
23 use util::logger::{Level, Logger};
24 use util::chacha20::ChaCha20;
28 use alloc::collections::BinaryHeap;
33 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
35 /// The node_id of the node at this hop.
36 pub pubkey: PublicKey,
37 /// The node_announcement features of the node at this hop. For the last hop, these may be
38 /// amended to match the features present in the invoice this node generated.
39 pub node_features: NodeFeatures,
40 /// The channel that should be used from the previous hop to reach this node.
41 pub short_channel_id: u64,
42 /// The channel_announcement features of the channel that should be used from the previous hop
43 /// to reach this node.
44 pub channel_features: ChannelFeatures,
45 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
46 /// For the last hop, this should be the full value of the payment (might be more than
47 /// requested if we had to match htlc_minimum_msat).
49 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
50 /// expected at the destination, in excess of the current block height.
51 pub cltv_expiry_delta: u32,
54 impl_writeable_tlv_based!(RouteHop, {
55 (0, pubkey, required),
56 (2, node_features, required),
57 (4, short_channel_id, required),
58 (6, channel_features, required),
59 (8, fee_msat, required),
60 (10, cltv_expiry_delta, required),
63 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
64 /// it can take multiple paths. Each path is composed of one or more hops through the network.
65 #[derive(Clone, Hash, PartialEq, Eq)]
67 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
68 /// last RouteHop in each path must be the same.
69 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
70 /// destination. Thus, this must always be at least length one. While the maximum length of any
71 /// given path is variable, keeping the length of any path to less than 20 should currently
72 /// ensure it is viable.
73 pub paths: Vec<Vec<RouteHop>>,
74 /// The `payment_params` parameter passed to [`find_route`].
75 /// This is used by `ChannelManager` to track information which may be required for retries,
76 /// provided back to you via [`Event::PaymentPathFailed`].
78 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
79 pub payment_params: Option<PaymentParameters>,
82 pub(crate) trait RoutePath {
83 /// Gets the fees for a given path, excluding any excess paid to the recipient.
84 fn get_path_fees(&self) -> u64;
86 impl RoutePath for Vec<RouteHop> {
87 fn get_path_fees(&self) -> u64 {
88 // Do not count last hop of each path since that's the full value of the payment
89 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
90 .iter().map(|hop| &hop.fee_msat)
96 /// Returns the total amount of fees paid on this [`Route`].
98 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
99 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
100 pub fn get_total_fees(&self) -> u64 {
101 self.paths.iter().map(|path| path.get_path_fees()).sum()
104 /// Returns the total amount paid on this [`Route`], excluding the fees.
105 pub fn get_total_amount(&self) -> u64 {
106 return self.paths.iter()
107 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
112 const SERIALIZATION_VERSION: u8 = 1;
113 const MIN_SERIALIZATION_VERSION: u8 = 1;
115 impl Writeable for Route {
116 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
117 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
118 (self.paths.len() as u64).write(writer)?;
119 for hops in self.paths.iter() {
120 (hops.len() as u8).write(writer)?;
121 for hop in hops.iter() {
125 write_tlv_fields!(writer, {
126 (1, self.payment_params, option),
132 impl Readable for Route {
133 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
134 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
135 let path_count: u64 = Readable::read(reader)?;
136 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
137 for _ in 0..path_count {
138 let hop_count: u8 = Readable::read(reader)?;
139 let mut hops = Vec::with_capacity(hop_count as usize);
140 for _ in 0..hop_count {
141 hops.push(Readable::read(reader)?);
145 let mut payment_params = None;
146 read_tlv_fields!(reader, {
147 (1, payment_params, option),
149 Ok(Route { paths, payment_params })
153 /// Parameters needed to find a [`Route`].
155 /// Passed to [`find_route`] and also provided in [`Event::PaymentPathFailed`] for retrying a failed
158 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
159 #[derive(Clone, Debug)]
160 pub struct RouteParameters {
161 /// The parameters of the failed payment path.
162 pub payment_params: PaymentParameters,
164 /// The amount in msats sent on the failed payment path.
165 pub final_value_msat: u64,
167 /// The CLTV on the final hop of the failed payment path.
168 pub final_cltv_expiry_delta: u32,
171 impl_writeable_tlv_based!(RouteParameters, {
172 (0, payment_params, required),
173 (2, final_value_msat, required),
174 (4, final_cltv_expiry_delta, required),
177 /// Maximum total CTLV difference we allow for a full payment path.
178 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
180 /// The median hop CLTV expiry delta currently seen in the network.
181 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
183 /// The recipient of a payment.
184 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
185 pub struct PaymentParameters {
186 /// The node id of the payee.
187 pub payee_pubkey: PublicKey,
189 /// Features supported by the payee.
191 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
192 /// does not contain any features.
194 /// [`for_keysend`]: Self::for_keysend
195 pub features: Option<InvoiceFeatures>,
197 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
198 pub route_hints: Vec<RouteHint>,
200 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
201 pub expiry_time: Option<u64>,
203 /// The maximum total CLTV delta we accept for the route.
204 pub max_total_cltv_expiry_delta: u32,
207 impl_writeable_tlv_based!(PaymentParameters, {
208 (0, payee_pubkey, required),
209 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
210 (2, features, option),
211 (4, route_hints, vec_type),
212 (6, expiry_time, option),
215 impl PaymentParameters {
216 /// Creates a payee with the node id of the given `pubkey`.
217 pub fn from_node_id(payee_pubkey: PublicKey) -> Self {
223 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
227 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
228 pub fn for_keysend(payee_pubkey: PublicKey) -> Self {
229 Self::from_node_id(payee_pubkey).with_features(InvoiceFeatures::for_keysend())
232 /// Includes the payee's features.
234 /// (C-not exported) since bindings don't support move semantics
235 pub fn with_features(self, features: InvoiceFeatures) -> Self {
236 Self { features: Some(features), ..self }
239 /// Includes hints for routing to the payee.
241 /// (C-not exported) since bindings don't support move semantics
242 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
243 Self { route_hints, ..self }
246 /// Includes a payment expiration in seconds relative to the UNIX epoch.
248 /// (C-not exported) since bindings don't support move semantics
249 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
250 Self { expiry_time: Some(expiry_time), ..self }
253 /// Includes a limit for the total CLTV expiry delta which is considered during routing
255 /// (C-not exported) since bindings don't support move semantics
256 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
257 Self { max_total_cltv_expiry_delta, ..self }
261 /// A list of hops along a payment path terminating with a channel to the recipient.
262 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
263 pub struct RouteHint(pub Vec<RouteHintHop>);
265 impl Writeable for RouteHint {
266 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
267 (self.0.len() as u64).write(writer)?;
268 for hop in self.0.iter() {
275 impl Readable for RouteHint {
276 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
277 let hop_count: u64 = Readable::read(reader)?;
278 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
279 for _ in 0..hop_count {
280 hops.push(Readable::read(reader)?);
286 /// A channel descriptor for a hop along a payment path.
287 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
288 pub struct RouteHintHop {
289 /// The node_id of the non-target end of the route
290 pub src_node_id: PublicKey,
291 /// The short_channel_id of this channel
292 pub short_channel_id: u64,
293 /// The fees which must be paid to use this channel
294 pub fees: RoutingFees,
295 /// The difference in CLTV values between this node and the next node.
296 pub cltv_expiry_delta: u16,
297 /// The minimum value, in msat, which must be relayed to the next hop.
298 pub htlc_minimum_msat: Option<u64>,
299 /// The maximum value in msat available for routing with a single HTLC.
300 pub htlc_maximum_msat: Option<u64>,
303 impl_writeable_tlv_based!(RouteHintHop, {
304 (0, src_node_id, required),
305 (1, htlc_minimum_msat, option),
306 (2, short_channel_id, required),
307 (3, htlc_maximum_msat, option),
309 (6, cltv_expiry_delta, required),
312 #[derive(Eq, PartialEq)]
313 struct RouteGraphNode {
315 lowest_fee_to_peer_through_node: u64,
316 lowest_fee_to_node: u64,
317 total_cltv_delta: u32,
318 // The maximum value a yet-to-be-constructed payment path might flow through this node.
319 // This value is upper-bounded by us by:
320 // - how much is needed for a path being constructed
321 // - how much value can channels following this node (up to the destination) can contribute,
322 // considering their capacity and fees
323 value_contribution_msat: u64,
324 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
325 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
326 path_htlc_minimum_msat: u64,
327 /// All penalties incurred from this hop on the way to the destination, as calculated using
329 path_penalty_msat: u64,
332 impl cmp::Ord for RouteGraphNode {
333 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
334 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat)
335 .saturating_add(other.path_penalty_msat);
336 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat)
337 .saturating_add(self.path_penalty_msat);
338 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
342 impl cmp::PartialOrd for RouteGraphNode {
343 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
344 Some(self.cmp(other))
348 /// A wrapper around the various hop representations.
350 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
351 #[derive(Clone, Debug)]
352 enum CandidateRouteHop<'a> {
353 /// A hop from the payer, where the outbound liquidity is known.
355 details: &'a ChannelDetails,
357 /// A hop found in the [`NetworkGraph`], where the channel capacity may or may not be known.
359 info: DirectedChannelInfoWithUpdate<'a>,
360 short_channel_id: u64,
362 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
364 hint: &'a RouteHintHop,
368 impl<'a> CandidateRouteHop<'a> {
369 fn short_channel_id(&self) -> u64 {
371 CandidateRouteHop::FirstHop { details } => details.short_channel_id.unwrap(),
372 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
373 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
377 // NOTE: This may alloc memory so avoid calling it in a hot code path.
378 fn features(&self) -> ChannelFeatures {
380 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
381 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
382 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
386 fn cltv_expiry_delta(&self) -> u32 {
388 CandidateRouteHop::FirstHop { .. } => 0,
389 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
390 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
394 fn htlc_minimum_msat(&self) -> u64 {
396 CandidateRouteHop::FirstHop { .. } => 0,
397 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
398 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
402 fn fees(&self) -> RoutingFees {
404 CandidateRouteHop::FirstHop { .. } => RoutingFees {
405 base_msat: 0, proportional_millionths: 0,
407 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
408 CandidateRouteHop::PrivateHop { hint } => hint.fees,
412 fn effective_capacity(&self) -> EffectiveCapacity {
414 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
415 liquidity_msat: details.outbound_capacity_msat,
417 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
418 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
423 /// It's useful to keep track of the hops associated with the fees required to use them,
424 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
425 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
426 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
428 struct PathBuildingHop<'a> {
429 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
430 // is a larger refactor and will require careful performance analysis.
432 candidate: CandidateRouteHop<'a>,
435 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
436 src_lowest_inbound_fees: RoutingFees,
437 /// All the fees paid *after* this channel on the way to the destination
438 next_hops_fee_msat: u64,
439 /// Fee paid for the use of the current channel (see candidate.fees()).
440 /// The value will be actually deducted from the counterparty balance on the previous link.
441 hop_use_fee_msat: u64,
442 /// Used to compare channels when choosing the for routing.
443 /// Includes paying for the use of a hop and the following hops, as well as
444 /// an estimated cost of reaching this hop.
445 /// Might get stale when fees are recomputed. Primarily for internal use.
447 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
448 /// walk and may be invalid thereafter.
449 path_htlc_minimum_msat: u64,
450 /// All penalties incurred from this channel on the way to the destination, as calculated using
452 path_penalty_msat: u64,
453 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
454 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
455 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
456 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
457 /// avoid processing them again.
459 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
460 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
461 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
462 // value_contribution_msat, which requires tracking it here. See comments below where it is
463 // used for more info.
464 value_contribution_msat: u64,
467 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
468 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
469 f.debug_struct("PathBuildingHop")
470 .field("node_id", &self.node_id)
471 .field("short_channel_id", &self.candidate.short_channel_id())
472 .field("total_fee_msat", &self.total_fee_msat)
473 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
474 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
475 .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)))
476 .field("path_penalty_msat", &self.path_penalty_msat)
477 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
478 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta())
483 // Instantiated with a list of hops with correct data in them collected during path finding,
484 // an instance of this struct should be further modified only via given methods.
486 struct PaymentPath<'a> {
487 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
490 impl<'a> PaymentPath<'a> {
491 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
492 fn get_value_msat(&self) -> u64 {
493 self.hops.last().unwrap().0.fee_msat
496 fn get_path_penalty_msat(&self) -> u64 {
497 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
500 fn get_total_fee_paid_msat(&self) -> u64 {
501 if self.hops.len() < 1 {
505 // Can't use next_hops_fee_msat because it gets outdated.
506 for (i, (hop, _)) in self.hops.iter().enumerate() {
507 if i != self.hops.len() - 1 {
508 result += hop.fee_msat;
514 fn get_cost_msat(&self) -> u64 {
515 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
518 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
519 // to change fees may result in an inconsistency.
521 // Sometimes we call this function right after constructing a path which is inconsistent in
522 // that it the value being transferred has decreased while we were doing path finding, leading
523 // to the fees being paid not lining up with the actual limits.
525 // Note that this function is not aware of the available_liquidity limit, and thus does not
526 // support increasing the value being transferred.
527 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
528 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
530 let mut total_fee_paid_msat = 0 as u64;
531 for i in (0..self.hops.len()).rev() {
532 let last_hop = i == self.hops.len() - 1;
534 // For non-last-hop, this value will represent the fees paid on the current hop. It
535 // will consist of the fees for the use of the next hop, and extra fees to match
536 // htlc_minimum_msat of the current channel. Last hop is handled separately.
537 let mut cur_hop_fees_msat = 0;
539 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
542 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
543 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
544 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
545 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
546 // set it too high just to maliciously take more fees by exploiting this
547 // match htlc_minimum_msat logic.
548 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
549 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
550 // Note that there is a risk that *previous hops* (those closer to us, as we go
551 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
553 // This might make us end up with a broken route, although this should be super-rare
554 // in practice, both because of how healthy channels look like, and how we pick
555 // channels in add_entry.
556 // Also, this can't be exploited more heavily than *announce a free path and fail
558 cur_hop_transferred_amount_msat += extra_fees_msat;
559 total_fee_paid_msat += extra_fees_msat;
560 cur_hop_fees_msat += extra_fees_msat;
564 // Final hop is a special case: it usually has just value_msat (by design), but also
565 // it still could overpay for the htlc_minimum_msat.
566 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
568 // Propagate updated fees for the use of the channels to one hop back, where they
569 // will be actually paid (fee_msat). The last hop is handled above separately.
570 cur_hop.fee_msat = cur_hop_fees_msat;
573 // Fee for the use of the current hop which will be deducted on the previous hop.
574 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
575 // this channel is free for us.
577 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
578 cur_hop.hop_use_fee_msat = new_fee;
579 total_fee_paid_msat += new_fee;
581 // It should not be possible because this function is called only to reduce the
582 // value. In that case, compute_fee was already called with the same fees for
583 // larger amount and there was no overflow.
591 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
592 let proportional_fee_millions =
593 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
594 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
595 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
599 // This function may be (indirectly) called without any verification,
600 // with channel_fees provided by a caller. We should handle it gracefully.
605 /// The default `features` we assume for a node in a route, when no `features` are known about that
608 /// Default features are:
609 /// * variable_length_onion_optional
610 fn default_node_features() -> NodeFeatures {
611 let mut features = NodeFeatures::empty();
612 features.set_variable_length_onion_optional();
616 /// Finds a route from us (payer) to the given target node (payee).
618 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
619 /// Without this, MPP will only be used if the payee's features are available in the network graph.
621 /// Private routing paths between a public node and the target may be included in `params.payee`.
623 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
624 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of our local
625 /// channels from [`NetworkGraph`] will be ignored, and only those in `first_hops` will be used.
627 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
628 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
629 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
633 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
634 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
639 /// Panics if first_hops contains channels without short_channel_ids;
640 /// [`ChannelManager::list_usable_channels`] will never include such channels.
642 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
643 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
644 pub fn find_route<L: Deref, S: Score>(
645 our_node_pubkey: &PublicKey, route_params: &RouteParameters, network: &NetworkGraph,
646 first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
647 ) -> Result<Route, LightningError>
648 where L::Target: Logger {
649 let network_graph = network.read_only();
651 our_node_pubkey, &route_params.payment_params, &network_graph, first_hops, route_params.final_value_msat,
652 route_params.final_cltv_expiry_delta, logger, scorer, random_seed_bytes
655 add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
658 Err(err) => Err(err),
662 pub(crate) fn get_route<L: Deref, S: Score>(
663 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
664 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
665 logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
666 ) -> Result<Route, LightningError>
667 where L::Target: Logger {
668 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
669 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
671 if payee_node_id == our_node_id {
672 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
675 if final_value_msat > MAX_VALUE_MSAT {
676 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
679 if final_value_msat == 0 {
680 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
683 for route in payment_params.route_hints.iter() {
684 for hop in &route.0 {
685 if hop.src_node_id == payment_params.payee_pubkey {
686 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
690 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
691 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});
694 // The general routing idea is the following:
695 // 1. Fill first/last hops communicated by the caller.
696 // 2. Attempt to construct a path from payer to payee for transferring
697 // any ~sufficient (described later) value.
698 // If succeed, remember which channels were used and how much liquidity they have available,
699 // so that future paths don't rely on the same liquidity.
700 // 3. Proceed to the next step if:
701 // - we hit the recommended target value;
702 // - OR if we could not construct a new path. Any next attempt will fail too.
703 // Otherwise, repeat step 2.
704 // 4. See if we managed to collect paths which aggregately are able to transfer target value
705 // (not recommended value).
706 // 5. If yes, proceed. If not, fail routing.
707 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
708 // 7. Of all the found paths, select only those with the lowest total fee.
709 // 8. The last path in every selected route is likely to be more than we need.
710 // Reduce its value-to-transfer and recompute fees.
711 // 9. Choose the best route by the lowest total fee.
713 // As for the actual search algorithm,
714 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
715 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
717 // We are not a faithful Dijkstra's implementation because we can change values which impact
718 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
719 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
720 // the value we are currently attempting to send over a path, we simply reduce the value being
721 // sent along the path for any hops after that channel. This may imply that later fees (which
722 // we've already tabulated) are lower because a smaller value is passing through the channels
723 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
724 // channels which were selected earlier (and which may still be used for other paths without a
725 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
728 // One potentially problematic case for this algorithm would be if there are many
729 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
730 // graph walking), we may never find a path which is not liquidity-limited and has lower
731 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
732 // Because we only consider paths with at least 5% of the total value being sent, the damage
733 // from such a case should be limited, however this could be further reduced in the future by
734 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
735 // limits for the purposes of fee calculation.
737 // Alternatively, we could store more detailed path information in the heap (targets, below)
738 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
739 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
740 // and practically (as we would need to store dynamically-allocated path information in heap
741 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
742 // results of such an algorithm would likely be biased towards lower-value paths.
744 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
745 // outside of our current search value, running a path search more times to gather candidate
746 // paths at different values. While this may be acceptable, further path searches may increase
747 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
748 // graph for candidate paths, calculating the maximum value which can realistically be sent at
749 // the same time, remaining generic across different payment values.
751 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
752 // to use as the A* heuristic beyond just the cost to get one node further than the current
755 let network_channels = network_graph.channels();
756 let network_nodes = network_graph.nodes();
758 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
759 // it. If the payee supports it they're supposed to include it in the invoice, so that should
761 let allow_mpp = if let Some(features) = &payment_params.features {
762 features.supports_basic_mpp()
763 } else if let Some(node) = network_nodes.get(&payee_node_id) {
764 if let Some(node_info) = node.announcement_info.as_ref() {
765 node_info.features.supports_basic_mpp()
768 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
769 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
770 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
773 // Prepare the data we'll use for payee-to-payer search by
774 // inserting first hops suggested by the caller as targets.
775 // Our search will then attempt to reach them while traversing from the payee node.
776 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
777 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
778 if let Some(hops) = first_hops {
780 if chan.short_channel_id.is_none() {
781 panic!("first_hops should be filled in with usable channels, not pending ones");
783 if chan.counterparty.node_id == *our_node_pubkey {
784 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
787 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
788 .or_insert(Vec::new())
791 if first_hop_targets.is_empty() {
792 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
796 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
797 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
798 // adding duplicate entries when we find a better path to a given node.
799 let mut targets = BinaryHeap::new();
801 // Map from node_id to information about the best current path to that node, including feerate
803 let mut dist = HashMap::with_capacity(network_nodes.len());
805 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
806 // indicating that we may wish to try again with a higher value, potentially paying to meet an
807 // htlc_minimum with extra fees while still finding a cheaper path.
808 let mut hit_minimum_limit;
810 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
811 // We start with a path_value of the exact amount we want, and if that generates a route we may
812 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
813 // amount we want in total across paths, selecting the best subset at the end.
814 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
815 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
816 let mut path_value_msat = final_value_msat;
818 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
819 // This map allows paths to be aware of the channel use by other paths in the same call.
820 // This would help to make a better path finding decisions and not "overbook" channels.
821 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
822 let mut bookkept_channels_liquidity_available_msat = HashMap::with_capacity(network_nodes.len());
824 // Keeping track of how much value we already collected across other paths. Helps to decide:
825 // - how much a new path should be transferring (upper bound);
826 // - whether a channel should be disregarded because
827 // it's available liquidity is too small comparing to how much more we need to collect;
828 // - when we want to stop looking for new paths.
829 let mut already_collected_value_msat = 0;
831 for (_, channels) in first_hop_targets.iter_mut() {
832 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
835 // First, if channels are below `recommended_value_msat`, sort them in descending order,
836 // preferring larger channels to avoid splitting the payment into more MPP parts than is
839 // Second, because simply always sorting in descending order would always use our largest
840 // available outbound capacity, needlessly fragmenting our available channel capacities,
841 // sort channels above `recommended_value_msat` in ascending order, preferring channels
842 // which have enough, but not too much, capacity for the payment.
843 channels.sort_unstable_by(|chan_a, chan_b| {
844 if chan_b.outbound_capacity_msat < recommended_value_msat || chan_a.outbound_capacity_msat < recommended_value_msat {
845 // Sort in descending order
846 chan_b.outbound_capacity_msat.cmp(&chan_a.outbound_capacity_msat)
848 // Sort in ascending order
849 chan_a.outbound_capacity_msat.cmp(&chan_b.outbound_capacity_msat)
854 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
856 macro_rules! add_entry {
857 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
858 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
859 // since that value has to be transferred over this channel.
860 // Returns whether this channel caused an update to `targets`.
861 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
862 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
863 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr ) => { {
864 // We "return" whether we updated the path at the end, via this:
865 let mut did_add_update_path_to_src_node = false;
866 // Channels to self should not be used. This is more of belt-and-suspenders, because in
867 // practice these cases should be caught earlier:
868 // - for regular channels at channel announcement (TODO)
869 // - for first and last hops early in get_route
870 if $src_node_id != $dest_node_id {
871 let short_channel_id = $candidate.short_channel_id();
872 let available_liquidity_msat = bookkept_channels_liquidity_available_msat
873 .entry(short_channel_id)
874 .or_insert_with(|| $candidate.effective_capacity().as_msat());
876 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
877 // It may be misleading because we might later choose to reduce the value transferred
878 // over these channels, and the channel which was insufficient might become sufficient.
879 // Worst case: we drop a good channel here because it can't cover the high following
880 // fees caused by one expensive channel, but then this channel could have been used
881 // if the amount being transferred over this path is lower.
882 // We do this for now, but this is a subject for removal.
883 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
885 // Routing Fragmentation Mitigation heuristic:
887 // Routing fragmentation across many payment paths increases the overall routing
888 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
889 // Taking too many smaller paths also increases the chance of payment failure.
890 // Thus to avoid this effect, we require from our collected links to provide
891 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
893 // This requirement is currently 5% of the remaining-to-be-collected value.
894 // This means as we successfully advance in our collection,
895 // the absolute liquidity contribution is lowered,
896 // thus increasing the number of potential channels to be selected.
898 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
899 // or 100% if we're not allowed to do multipath payments.
900 let minimal_value_contribution_msat: u64 = if allow_mpp {
901 (recommended_value_msat - already_collected_value_msat + 19) / 20
905 // Verify the liquidity offered by this channel complies to the minimal contribution.
906 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
908 // Do not consider candidates that exceed the maximum total cltv expiry limit.
909 // In order to already account for some of the privacy enhancing random CLTV
910 // expiry delta offset we add on top later, we subtract a rough estimate
911 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
912 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
913 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
914 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
915 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
916 .saturating_add($candidate.cltv_expiry_delta());
917 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
919 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
920 // Includes paying fees for the use of the following channels.
921 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
922 Some(result) => result,
923 // Can't overflow due to how the values were computed right above.
924 None => unreachable!(),
926 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
927 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
928 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
930 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
931 let may_overpay_to_meet_path_minimum_msat =
932 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
933 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
934 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
935 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
937 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
938 // bother considering this channel. If retrying with recommended_value_msat may
939 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
940 // around again with a higher amount.
941 if contributes_sufficient_value && doesnt_exceed_cltv_delta_limit && may_overpay_to_meet_path_minimum_msat {
942 hit_minimum_limit = true;
943 } else if contributes_sufficient_value && doesnt_exceed_cltv_delta_limit && over_path_minimum_msat {
944 // Note that low contribution here (limited by available_liquidity_msat)
945 // might violate htlc_minimum_msat on the hops which are next along the
946 // payment path (upstream to the payee). To avoid that, we recompute
947 // path fees knowing the final path contribution after constructing it.
948 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
949 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
950 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
951 .unwrap_or_else(|| u64::max_value());
952 let hm_entry = dist.entry($src_node_id);
953 let old_entry = hm_entry.or_insert_with(|| {
954 // If there was previously no known way to access the source node
955 // (recall it goes payee-to-payer) of short_channel_id, first add a
956 // semi-dummy record just to compute the fees to reach the source node.
957 // This will affect our decision on selecting short_channel_id
958 // as a way to reach the $dest_node_id.
959 let mut fee_base_msat = 0;
960 let mut fee_proportional_millionths = 0;
961 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
962 fee_base_msat = fees.base_msat;
963 fee_proportional_millionths = fees.proportional_millionths;
966 node_id: $dest_node_id.clone(),
967 candidate: $candidate.clone(),
969 src_lowest_inbound_fees: RoutingFees {
970 base_msat: fee_base_msat,
971 proportional_millionths: fee_proportional_millionths,
973 next_hops_fee_msat: u64::max_value(),
974 hop_use_fee_msat: u64::max_value(),
975 total_fee_msat: u64::max_value(),
976 path_htlc_minimum_msat,
977 path_penalty_msat: u64::max_value(),
978 was_processed: false,
979 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
980 value_contribution_msat,
984 #[allow(unused_mut)] // We only use the mut in cfg(test)
985 let mut should_process = !old_entry.was_processed;
986 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
988 // In test/fuzzing builds, we do extra checks to make sure the skipping
989 // of already-seen nodes only happens in cases we expect (see below).
990 if !should_process { should_process = true; }
994 let mut hop_use_fee_msat = 0;
995 let mut total_fee_msat = $next_hops_fee_msat;
997 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
998 // will have the same effective-fee
999 if $src_node_id != our_node_id {
1000 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
1001 // max_value means we'll always fail
1002 // the old_entry.total_fee_msat > total_fee_msat check
1003 None => total_fee_msat = u64::max_value(),
1005 hop_use_fee_msat = fee_msat;
1006 total_fee_msat += hop_use_fee_msat;
1007 // When calculating the lowest inbound fees to a node, we
1008 // calculate fees here not based on the actual value we think
1009 // will flow over this channel, but on the minimum value that
1010 // we'll accept flowing over it. The minimum accepted value
1011 // is a constant through each path collection run, ensuring
1012 // consistent basis. Otherwise we may later find a
1013 // different path to the source node that is more expensive,
1014 // but which we consider to be cheaper because we are capacity
1015 // constrained and the relative fee becomes lower.
1016 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
1017 .map(|a| a.checked_add(total_fee_msat)) {
1022 total_fee_msat = u64::max_value();
1029 let path_penalty_msat = $next_hops_path_penalty_msat.saturating_add(
1030 scorer.channel_penalty_msat(short_channel_id, amount_to_transfer_over_msat,
1031 *available_liquidity_msat, &$src_node_id, &$dest_node_id));
1032 let new_graph_node = RouteGraphNode {
1033 node_id: $src_node_id,
1034 lowest_fee_to_peer_through_node: total_fee_msat,
1035 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1036 total_cltv_delta: hop_total_cltv_delta,
1037 value_contribution_msat: value_contribution_msat,
1038 path_htlc_minimum_msat,
1042 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1043 // if this way is cheaper than the already known
1044 // (considering the cost to "reach" this channel from the route destination,
1045 // the cost of using this channel,
1046 // and the cost of routing to the source node of this channel).
1047 // Also, consider that htlc_minimum_msat_difference, because we might end up
1048 // paying it. Consider the following exploit:
1049 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1050 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1051 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1052 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1054 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1055 // but it may require additional tracking - we don't want to double-count
1056 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1057 // can't use something that may decrease on future hops.
1058 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1059 .saturating_add(old_entry.path_penalty_msat);
1060 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1061 .saturating_add(path_penalty_msat);
1063 if !old_entry.was_processed && new_cost < old_cost {
1064 targets.push(new_graph_node);
1065 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1066 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1067 old_entry.total_fee_msat = total_fee_msat;
1068 old_entry.node_id = $dest_node_id.clone();
1069 old_entry.candidate = $candidate.clone();
1070 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1071 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1072 old_entry.path_penalty_msat = path_penalty_msat;
1073 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1075 old_entry.value_contribution_msat = value_contribution_msat;
1077 did_add_update_path_to_src_node = true;
1078 } else if old_entry.was_processed && new_cost < old_cost {
1079 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1081 // If we're skipping processing a node which was previously
1082 // processed even though we found another path to it with a
1083 // cheaper fee, check that it was because the second path we
1084 // found (which we are processing now) has a lower value
1085 // contribution due to an HTLC minimum limit.
1087 // e.g. take a graph with two paths from node 1 to node 2, one
1088 // through channel A, and one through channel B. Channel A and
1089 // B are both in the to-process heap, with their scores set by
1090 // a higher htlc_minimum than fee.
1091 // Channel A is processed first, and the channels onwards from
1092 // node 1 are added to the to-process heap. Thereafter, we pop
1093 // Channel B off of the heap, note that it has a much more
1094 // restrictive htlc_maximum_msat, and recalculate the fees for
1095 // all of node 1's channels using the new, reduced, amount.
1097 // This would be bogus - we'd be selecting a higher-fee path
1098 // with a lower htlc_maximum_msat instead of the one we'd
1099 // already decided to use.
1100 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1102 value_contribution_msat + path_penalty_msat <
1103 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1111 did_add_update_path_to_src_node
1115 let default_node_features = default_node_features();
1117 // Find ways (channels with destination) to reach a given node and store them
1118 // in the corresponding data structures (routing graph etc).
1119 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1120 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1121 // This data can later be helpful to optimize routing (pay lower fees).
1122 macro_rules! add_entries_to_cheapest_to_target_node {
1123 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr ) => {
1124 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1125 let was_processed = elem.was_processed;
1126 elem.was_processed = true;
1129 // Entries are added to dist in add_entry!() when there is a channel from a node.
1130 // Because there are no channels from payee, it will not have a dist entry at this point.
1131 // If we're processing any other node, it is always be the result of a channel from it.
1132 assert_eq!($node_id, payee_node_id);
1137 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1138 for details in first_channels {
1139 let candidate = CandidateRouteHop::FirstHop { details };
1140 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat, $next_hops_cltv_delta);
1144 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1147 &default_node_features
1150 if !features.requires_unknown_bits() {
1151 for chan_id in $node.channels.iter() {
1152 let chan = network_channels.get(chan_id).unwrap();
1153 if !chan.features.requires_unknown_bits() {
1154 let (directed_channel, source) =
1155 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1156 if first_hops.is_none() || *source != our_node_id {
1157 if let Some(direction) = directed_channel.direction() {
1158 if direction.enabled {
1159 let candidate = CandidateRouteHop::PublicHop {
1160 info: directed_channel.with_update().unwrap(),
1161 short_channel_id: *chan_id,
1163 add_entry!(candidate, *source, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat, $next_hops_cltv_delta);
1174 let mut payment_paths = Vec::<PaymentPath>::new();
1176 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1177 'paths_collection: loop {
1178 // For every new path, start from scratch, except
1179 // bookkept_channels_liquidity_available_msat, which will improve
1180 // the further iterations of path finding. Also don't erase first_hop_targets.
1183 hit_minimum_limit = false;
1185 // If first hop is a private channel and the only way to reach the payee, this is the only
1186 // place where it could be added.
1187 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1188 for details in first_channels {
1189 let candidate = CandidateRouteHop::FirstHop { details };
1190 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1191 log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1195 // Add the payee as a target, so that the payee-to-payer
1196 // search algorithm knows what to start with.
1197 match network_nodes.get(&payee_node_id) {
1198 // The payee is not in our network graph, so nothing to add here.
1199 // There is still a chance of reaching them via last_hops though,
1200 // so don't yet fail the payment here.
1201 // If not, targets.pop() will not even let us enter the loop in step 2.
1204 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1209 // If a caller provided us with last hops, add them to routing targets. Since this happens
1210 // earlier than general path finding, they will be somewhat prioritized, although currently
1211 // it matters only if the fees are exactly the same.
1212 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1213 let first_hop_in_route = &(route.0)[0];
1214 let have_hop_src_in_graph =
1215 // Only add the hops in this route to our candidate set if either
1216 // we have a direct channel to the first hop or the first hop is
1217 // in the regular network graph.
1218 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1219 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1220 if have_hop_src_in_graph {
1221 // We start building the path from reverse, i.e., from payee
1222 // to the first RouteHintHop in the path.
1223 let hop_iter = route.0.iter().rev();
1224 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1225 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1226 let mut hop_used = true;
1227 let mut aggregate_next_hops_fee_msat: u64 = 0;
1228 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1229 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1230 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1232 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1233 let source = NodeId::from_pubkey(&hop.src_node_id);
1234 let target = NodeId::from_pubkey(&prev_hop_id);
1235 let candidate = network_channels
1236 .get(&hop.short_channel_id)
1237 .and_then(|channel| channel.as_directed_to(&target))
1238 .and_then(|(channel, _)| channel.with_update())
1239 .map(|info| CandidateRouteHop::PublicHop {
1241 short_channel_id: hop.short_channel_id,
1243 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1244 let capacity_msat = candidate.effective_capacity().as_msat();
1245 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1246 .saturating_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, capacity_msat, &source, &target));
1248 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1249 .saturating_add(hop.cltv_expiry_delta as u32);
1251 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta) {
1252 // If this hop was not used then there is no use checking the preceding hops
1253 // in the RouteHint. We can break by just searching for a direct channel between
1254 // last checked hop and first_hop_targets
1258 // Searching for a direct channel between last checked hop and first_hop_targets
1259 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1260 for details in first_channels {
1261 let candidate = CandidateRouteHop::FirstHop { details };
1262 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta);
1270 // In the next values of the iterator, the aggregate fees already reflects
1271 // the sum of value sent from payer (final_value_msat) and routing fees
1272 // for the last node in the RouteHint. We need to just add the fees to
1273 // route through the current node so that the preceeding node (next iteration)
1275 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1276 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1277 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1279 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1280 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1281 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1282 .checked_add(hop_htlc_minimum_msat_inc);
1283 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1285 if idx == route.0.len() - 1 {
1286 // The last hop in this iterator is the first hop in
1287 // overall RouteHint.
1288 // If this hop connects to a node with which we have a direct channel,
1289 // ignore the network graph and, if the last hop was added, add our
1290 // direct channel to the candidate set.
1292 // Note that we *must* check if the last hop was added as `add_entry`
1293 // always assumes that the third argument is a node to which we have a
1295 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1296 for details in first_channels {
1297 let candidate = CandidateRouteHop::FirstHop { details };
1298 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&hop.src_node_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta);
1306 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1308 // At this point, targets are filled with the data from first and
1309 // last hops communicated by the caller, and the payment receiver.
1310 let mut found_new_path = false;
1313 // If this loop terminates due the exhaustion of targets, two situations are possible:
1314 // - not enough outgoing liquidity:
1315 // 0 < already_collected_value_msat < final_value_msat
1316 // - enough outgoing liquidity:
1317 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1318 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1319 // paths_collection will be stopped because found_new_path==false.
1320 // This is not necessarily a routing failure.
1321 'path_construction: while let Some(RouteGraphNode { node_id, lowest_fee_to_node, total_cltv_delta, value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, .. }) = targets.pop() {
1323 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1324 // traversing the graph and arrange the path out of what we found.
1325 if node_id == our_node_id {
1326 let mut new_entry = dist.remove(&our_node_id).unwrap();
1327 let mut ordered_hops = vec!((new_entry.clone(), default_node_features.clone()));
1330 let mut features_set = false;
1331 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1332 for details in first_channels {
1333 if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1334 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1335 features_set = true;
1341 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1342 if let Some(node_info) = node.announcement_info.as_ref() {
1343 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1345 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1348 // We can fill in features for everything except hops which were
1349 // provided via the invoice we're paying. We could guess based on the
1350 // recipient's features but for now we simply avoid guessing at all.
1354 // Means we succesfully traversed from the payer to the payee, now
1355 // save this path for the payment route. Also, update the liquidity
1356 // remaining on the used hops, so that we take them into account
1357 // while looking for more paths.
1358 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1362 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1363 Some(payment_hop) => payment_hop,
1364 // We can't arrive at None because, if we ever add an entry to targets,
1365 // we also fill in the entry in dist (see add_entry!).
1366 None => unreachable!(),
1368 // We "propagate" the fees one hop backward (topologically) here,
1369 // so that fees paid for a HTLC forwarding on the current channel are
1370 // associated with the previous channel (where they will be subtracted).
1371 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1372 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1374 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1375 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1377 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1378 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1380 let mut payment_path = PaymentPath {hops: ordered_hops};
1382 // We could have possibly constructed a slightly inconsistent path: since we reduce
1383 // value being transferred along the way, we could have violated htlc_minimum_msat
1384 // on some channels we already passed (assuming dest->source direction). Here, we
1385 // recompute the fees again, so that if that's the case, we match the currently
1386 // underpaid htlc_minimum_msat with fees.
1387 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1389 // Since a path allows to transfer as much value as
1390 // the smallest channel it has ("bottleneck"), we should recompute
1391 // the fees so sender HTLC don't overpay fees when traversing
1392 // larger channels than the bottleneck. This may happen because
1393 // when we were selecting those channels we were not aware how much value
1394 // this path will transfer, and the relative fee for them
1395 // might have been computed considering a larger value.
1396 // Remember that we used these channels so that we don't rely
1397 // on the same liquidity in future paths.
1398 let mut prevented_redundant_path_selection = false;
1399 for (payment_hop, _) in payment_path.hops.iter() {
1400 let channel_liquidity_available_msat = bookkept_channels_liquidity_available_msat.get_mut(&payment_hop.candidate.short_channel_id()).unwrap();
1401 let mut spent_on_hop_msat = value_contribution_msat;
1402 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
1403 spent_on_hop_msat += next_hops_fee_msat;
1404 if spent_on_hop_msat == *channel_liquidity_available_msat {
1405 // If this path used all of this channel's available liquidity, we know
1406 // this path will not be selected again in the next loop iteration.
1407 prevented_redundant_path_selection = true;
1409 *channel_liquidity_available_msat -= spent_on_hop_msat;
1411 if !prevented_redundant_path_selection {
1412 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1413 // we'll probably end up picking the same path again on the next iteration.
1414 // Decrease the available liquidity of a hop in the middle of the path.
1415 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1416 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1417 let victim_liquidity = bookkept_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1418 *victim_liquidity = 0;
1421 // Track the total amount all our collected paths allow to send so that we:
1422 // - know when to stop looking for more paths
1423 // - know which of the hops are useless considering how much more sats we need
1424 // (contributes_sufficient_value)
1425 already_collected_value_msat += value_contribution_msat;
1427 payment_paths.push(payment_path);
1428 found_new_path = true;
1429 break 'path_construction;
1432 // If we found a path back to the payee, we shouldn't try to process it again. This is
1433 // the equivalent of the `elem.was_processed` check in
1434 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1435 if node_id == payee_node_id { continue 'path_construction; }
1437 // Otherwise, since the current target node is not us,
1438 // keep "unrolling" the payment graph from payee to payer by
1439 // finding a way to reach the current target from the payer side.
1440 match network_nodes.get(&node_id) {
1443 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, total_cltv_delta);
1449 // If we don't support MPP, no use trying to gather more value ever.
1450 break 'paths_collection;
1454 // Stop either when the recommended value is reached or if no new path was found in this
1456 // In the latter case, making another path finding attempt won't help,
1457 // because we deterministically terminated the search due to low liquidity.
1458 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1459 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1460 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1461 break 'paths_collection;
1462 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1463 // Further, if this was our first walk of the graph, and we weren't limited by an
1464 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1465 // limited by an htlc_minimum_msat value, find another path with a higher value,
1466 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1467 // still keeping a lower total fee than this path.
1468 if !hit_minimum_limit {
1469 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1470 break 'paths_collection;
1472 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1473 path_value_msat = recommended_value_msat;
1478 if payment_paths.len() == 0 {
1479 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1482 if already_collected_value_msat < final_value_msat {
1483 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1486 // Sort by total fees and take the best paths.
1487 payment_paths.sort_unstable_by_key(|path| path.get_total_fee_paid_msat());
1488 if payment_paths.len() > 50 {
1489 payment_paths.truncate(50);
1492 // Draw multiple sufficient routes by randomly combining the selected paths.
1493 let mut drawn_routes = Vec::new();
1494 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 12]);
1495 let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
1497 let num_permutations = payment_paths.len();
1498 for _ in 0..num_permutations {
1499 let mut cur_route = Vec::<PaymentPath>::new();
1500 let mut aggregate_route_value_msat = 0;
1503 // Do a Fisher-Yates shuffle to create a random permutation of the payment paths
1504 for cur_index in (1..payment_paths.len()).rev() {
1505 prng.process_in_place(&mut random_index_bytes);
1506 let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
1507 payment_paths.swap(cur_index, random_index);
1511 for payment_path in &payment_paths {
1512 cur_route.push(payment_path.clone());
1513 aggregate_route_value_msat += payment_path.get_value_msat();
1514 if aggregate_route_value_msat > final_value_msat {
1515 // Last path likely overpaid. Substract it from the most expensive
1516 // (in terms of proportional fee) path in this route and recompute fees.
1517 // This might be not the most economically efficient way, but fewer paths
1518 // also makes routing more reliable.
1519 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1521 // First, we drop some expensive low-value paths entirely if possible, since fewer
1522 // paths is better: the payment is less likely to fail. In order to do so, we sort
1523 // by value and fall back to total fees paid, i.e., in case of equal values we
1524 // prefer lower cost paths.
1525 cur_route.sort_unstable_by(|a, b| {
1526 a.get_value_msat().cmp(&b.get_value_msat())
1527 // Reverse ordering for cost, so we drop higher-cost paths first
1528 .then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
1531 // We should make sure that at least 1 path left.
1532 let mut paths_left = cur_route.len();
1533 cur_route.retain(|path| {
1534 if paths_left == 1 {
1537 let mut keep = true;
1538 let path_value_msat = path.get_value_msat();
1539 if path_value_msat <= overpaid_value_msat {
1541 overpaid_value_msat -= path_value_msat;
1547 if overpaid_value_msat == 0 {
1551 assert!(cur_route.len() > 0);
1554 // Now, subtract the overpaid value from the most-expensive path.
1555 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1556 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1557 cur_route.sort_unstable_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1558 let expensive_payment_path = cur_route.first_mut().unwrap();
1560 // We already dropped all the small value paths above, meaning all the
1561 // remaining paths are larger than remaining overpaid_value_msat.
1562 // Thus, this can't be negative.
1563 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1564 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1568 drawn_routes.push(cur_route);
1572 // Select the best route by lowest total cost.
1573 drawn_routes.sort_unstable_by_key(|paths| paths.iter().map(|path| path.get_cost_msat()).sum::<u64>());
1574 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1575 for payment_path in drawn_routes.first().unwrap() {
1576 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1578 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)})?,
1579 node_features: node_features.clone(),
1580 short_channel_id: payment_hop.candidate.short_channel_id(),
1581 channel_features: payment_hop.candidate.features(),
1582 fee_msat: payment_hop.fee_msat,
1583 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1585 }).collect::<Vec<_>>();
1586 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1587 // applicable for the previous hop.
1588 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1589 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1591 selected_paths.push(path);
1594 if let Some(features) = &payment_params.features {
1595 for path in selected_paths.iter_mut() {
1596 if let Ok(route_hop) = path.last_mut().unwrap() {
1597 route_hop.node_features = features.to_context();
1603 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1604 payment_params: Some(payment_params.clone()),
1606 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1610 // When an adversarial intermediary node observes a payment, it may be able to infer its
1611 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1612 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1613 // payment path by adding a randomized 'shadow route' offset to the final hop.
1614 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]) {
1615 let network_channels = network_graph.channels();
1616 let network_nodes = network_graph.nodes();
1618 for path in route.paths.iter_mut() {
1619 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1621 // Remember the last three nodes of the random walk and avoid looping back on them.
1622 // Init with the last three nodes from the actual path, if possible.
1623 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.last().unwrap().pubkey),
1624 NodeId::from_pubkey(&path.get(path.len().saturating_sub(2)).unwrap().pubkey),
1625 NodeId::from_pubkey(&path.get(path.len().saturating_sub(3)).unwrap().pubkey)];
1627 // Choose the last publicly known node as the starting point for the random walk.
1628 let mut cur_hop: Option<NodeId> = None;
1629 let mut path_nonce = [0u8; 12];
1630 if let Some(starting_hop) = path.iter().rev()
1631 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1632 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
1633 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
1636 // Init PRNG with the path-dependant nonce, which is static for private paths.
1637 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1638 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1640 // Pick a random path length in [1 .. 3]
1641 prng.process_in_place(&mut random_path_bytes);
1642 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1644 for random_hop in 0..random_walk_length {
1645 // If we don't find a suitable offset in the public network graph, we default to
1646 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1647 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1649 if let Some(cur_node_id) = cur_hop {
1650 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1651 // Randomly choose the next unvisited hop.
1652 prng.process_in_place(&mut random_path_bytes);
1653 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
1654 .checked_rem(cur_node.channels.len())
1655 .and_then(|index| cur_node.channels.get(index))
1656 .and_then(|id| network_channels.get(id)) {
1657 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1658 if !nodes_to_avoid.iter().any(|x| x == next_id) {
1659 nodes_to_avoid[random_hop] = *next_id;
1660 dir_info.direction().map(|channel_update_info| {
1661 random_hop_offset = channel_update_info.cltv_expiry_delta.into();
1662 cur_hop = Some(*next_id);
1670 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1671 .checked_add(random_hop_offset)
1672 .unwrap_or(shadow_ctlv_expiry_delta_offset);
1675 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1676 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1677 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1679 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1680 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1681 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1682 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1683 max_path_offset = cmp::max(
1684 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1685 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1686 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1688 // Add 'shadow' CLTV offset to the final hop
1689 if let Some(last_hop) = path.last_mut() {
1690 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1691 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1698 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler, NodeId};
1699 use routing::router::{get_route, add_random_cltv_offset, default_node_features, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA};
1700 use routing::scoring::Score;
1701 use chain::transaction::OutPoint;
1702 use chain::keysinterface::KeysInterface;
1703 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1704 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1705 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1706 use ln::channelmanager;
1707 use util::test_utils;
1708 use util::chacha20::ChaCha20;
1709 use util::ser::Writeable;
1711 use util::ser::Writer;
1713 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1714 use bitcoin::hashes::Hash;
1715 use bitcoin::network::constants::Network;
1716 use bitcoin::blockdata::constants::genesis_block;
1717 use bitcoin::blockdata::script::Builder;
1718 use bitcoin::blockdata::opcodes;
1719 use bitcoin::blockdata::transaction::TxOut;
1723 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1724 use bitcoin::secp256k1::{Secp256k1, All};
1727 use sync::{self, Arc};
1729 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1730 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1731 channelmanager::ChannelDetails {
1732 channel_id: [0; 32],
1733 counterparty: channelmanager::ChannelCounterparty {
1736 unspendable_punishment_reserve: 0,
1737 forwarding_info: None,
1739 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1742 inbound_scid_alias: None,
1743 channel_value_satoshis: 0,
1746 outbound_capacity_msat,
1747 inbound_capacity_msat: 42,
1748 unspendable_punishment_reserve: None,
1749 confirmations_required: None,
1750 force_close_spend_delay: None,
1751 is_outbound: true, is_funding_locked: true,
1752 is_usable: true, is_public: true,
1753 inbound_htlc_minimum_msat: None,
1754 inbound_htlc_maximum_msat: None,
1758 // Using the same keys for LN and BTC ids
1760 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1761 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1763 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1764 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1766 let unsigned_announcement = UnsignedChannelAnnouncement {
1768 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1772 bitcoin_key_1: node_id_1,
1773 bitcoin_key_2: node_id_2,
1774 excess_data: Vec::new(),
1777 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1778 let valid_announcement = ChannelAnnouncement {
1779 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1780 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1781 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1782 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1783 contents: unsigned_announcement.clone(),
1785 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1786 Ok(res) => assert!(res),
1792 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1793 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1795 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1796 let valid_channel_update = ChannelUpdate {
1797 signature: secp_ctx.sign(&msghash, node_privkey),
1798 contents: update.clone()
1801 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1802 Ok(res) => assert!(res),
1807 fn add_or_update_node(
1808 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1809 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1811 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1812 let unsigned_announcement = UnsignedNodeAnnouncement {
1818 addresses: Vec::new(),
1819 excess_address_data: Vec::new(),
1820 excess_data: Vec::new(),
1822 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1823 let valid_announcement = NodeAnnouncement {
1824 signature: secp_ctx.sign(&msghash, node_privkey),
1825 contents: unsigned_announcement.clone()
1828 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1834 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1835 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1836 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
1839 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1841 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1842 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1844 (our_privkey, our_id, privkeys, pubkeys)
1847 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1848 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1849 // test for it later.
1850 let idx = (id - 1) * 2 + 1;
1852 vec![1 << (idx - 8*3), 0, 0, 0]
1853 } else if idx > 8*2 {
1854 vec![1 << (idx - 8*2), 0, 0]
1855 } else if idx > 8*1 {
1856 vec![1 << (idx - 8*1), 0]
1862 fn build_graph() -> (
1864 sync::Arc<NetworkGraph>,
1865 NetGraphMsgHandler<sync::Arc<NetworkGraph>, sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>,
1866 sync::Arc<test_utils::TestChainSource>,
1867 sync::Arc<test_utils::TestLogger>,
1869 let secp_ctx = Secp256k1::new();
1870 let logger = Arc::new(test_utils::TestLogger::new());
1871 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1872 let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
1873 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
1874 // Build network from our_id to node6:
1876 // -1(1)2- node0 -1(3)2-
1878 // our_id -1(12)2- node7 -1(13)2--- node2
1880 // -1(2)2- node1 -1(4)2-
1883 // chan1 1-to-2: disabled
1884 // chan1 2-to-1: enabled, 0 fee
1886 // chan2 1-to-2: enabled, ignored fee
1887 // chan2 2-to-1: enabled, 0 fee
1889 // chan3 1-to-2: enabled, 0 fee
1890 // chan3 2-to-1: enabled, 100 msat fee
1892 // chan4 1-to-2: enabled, 100% fee
1893 // chan4 2-to-1: enabled, 0 fee
1895 // chan12 1-to-2: enabled, ignored fee
1896 // chan12 2-to-1: enabled, 0 fee
1898 // chan13 1-to-2: enabled, 200% fee
1899 // chan13 2-to-1: enabled, 0 fee
1902 // -1(5)2- node3 -1(8)2--
1906 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1908 // -1(7)2- node5 -1(10)2-
1910 // Channels 5, 8, 9 and 10 are private channels.
1912 // chan5 1-to-2: enabled, 100 msat fee
1913 // chan5 2-to-1: enabled, 0 fee
1915 // chan6 1-to-2: enabled, 0 fee
1916 // chan6 2-to-1: enabled, 0 fee
1918 // chan7 1-to-2: enabled, 100% fee
1919 // chan7 2-to-1: enabled, 0 fee
1921 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1922 // chan8 2-to-1: enabled, 0 fee
1924 // chan9 1-to-2: enabled, 1001 msat fee
1925 // chan9 2-to-1: enabled, 0 fee
1927 // chan10 1-to-2: enabled, 0 fee
1928 // chan10 2-to-1: enabled, 0 fee
1930 // chan11 1-to-2: enabled, 0 fee
1931 // chan11 2-to-1: enabled, 0 fee
1933 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1935 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1936 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1937 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1938 short_channel_id: 1,
1941 cltv_expiry_delta: 0,
1942 htlc_minimum_msat: 0,
1943 htlc_maximum_msat: OptionalField::Absent,
1945 fee_proportional_millionths: 0,
1946 excess_data: Vec::new()
1949 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1951 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1952 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1953 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1954 short_channel_id: 2,
1957 cltv_expiry_delta: (5 << 4) | 3,
1958 htlc_minimum_msat: 0,
1959 htlc_maximum_msat: OptionalField::Absent,
1960 fee_base_msat: u32::max_value(),
1961 fee_proportional_millionths: u32::max_value(),
1962 excess_data: Vec::new()
1964 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1965 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1966 short_channel_id: 2,
1969 cltv_expiry_delta: 0,
1970 htlc_minimum_msat: 0,
1971 htlc_maximum_msat: OptionalField::Absent,
1973 fee_proportional_millionths: 0,
1974 excess_data: Vec::new()
1977 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1979 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1980 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1981 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1982 short_channel_id: 12,
1985 cltv_expiry_delta: (5 << 4) | 3,
1986 htlc_minimum_msat: 0,
1987 htlc_maximum_msat: OptionalField::Absent,
1988 fee_base_msat: u32::max_value(),
1989 fee_proportional_millionths: u32::max_value(),
1990 excess_data: Vec::new()
1992 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1993 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1994 short_channel_id: 12,
1997 cltv_expiry_delta: 0,
1998 htlc_minimum_msat: 0,
1999 htlc_maximum_msat: OptionalField::Absent,
2001 fee_proportional_millionths: 0,
2002 excess_data: Vec::new()
2005 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
2007 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
2008 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2009 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2010 short_channel_id: 3,
2013 cltv_expiry_delta: (3 << 4) | 1,
2014 htlc_minimum_msat: 0,
2015 htlc_maximum_msat: OptionalField::Absent,
2017 fee_proportional_millionths: 0,
2018 excess_data: Vec::new()
2020 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2021 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2022 short_channel_id: 3,
2025 cltv_expiry_delta: (3 << 4) | 2,
2026 htlc_minimum_msat: 0,
2027 htlc_maximum_msat: OptionalField::Absent,
2029 fee_proportional_millionths: 0,
2030 excess_data: Vec::new()
2033 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
2034 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2036 short_channel_id: 4,
2039 cltv_expiry_delta: (4 << 4) | 1,
2040 htlc_minimum_msat: 0,
2041 htlc_maximum_msat: OptionalField::Absent,
2043 fee_proportional_millionths: 1000000,
2044 excess_data: Vec::new()
2046 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2047 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2048 short_channel_id: 4,
2051 cltv_expiry_delta: (4 << 4) | 2,
2052 htlc_minimum_msat: 0,
2053 htlc_maximum_msat: OptionalField::Absent,
2055 fee_proportional_millionths: 0,
2056 excess_data: Vec::new()
2059 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2060 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2061 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2062 short_channel_id: 13,
2065 cltv_expiry_delta: (13 << 4) | 1,
2066 htlc_minimum_msat: 0,
2067 htlc_maximum_msat: OptionalField::Absent,
2069 fee_proportional_millionths: 2000000,
2070 excess_data: Vec::new()
2072 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2073 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2074 short_channel_id: 13,
2077 cltv_expiry_delta: (13 << 4) | 2,
2078 htlc_minimum_msat: 0,
2079 htlc_maximum_msat: OptionalField::Absent,
2081 fee_proportional_millionths: 0,
2082 excess_data: Vec::new()
2085 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2087 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2088 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2089 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2090 short_channel_id: 6,
2093 cltv_expiry_delta: (6 << 4) | 1,
2094 htlc_minimum_msat: 0,
2095 htlc_maximum_msat: OptionalField::Absent,
2097 fee_proportional_millionths: 0,
2098 excess_data: Vec::new()
2100 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2101 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2102 short_channel_id: 6,
2105 cltv_expiry_delta: (6 << 4) | 2,
2106 htlc_minimum_msat: 0,
2107 htlc_maximum_msat: OptionalField::Absent,
2109 fee_proportional_millionths: 0,
2110 excess_data: Vec::new(),
2113 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2114 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2115 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2116 short_channel_id: 11,
2119 cltv_expiry_delta: (11 << 4) | 1,
2120 htlc_minimum_msat: 0,
2121 htlc_maximum_msat: OptionalField::Absent,
2123 fee_proportional_millionths: 0,
2124 excess_data: Vec::new()
2126 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2127 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2128 short_channel_id: 11,
2131 cltv_expiry_delta: (11 << 4) | 2,
2132 htlc_minimum_msat: 0,
2133 htlc_maximum_msat: OptionalField::Absent,
2135 fee_proportional_millionths: 0,
2136 excess_data: Vec::new()
2139 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2141 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2143 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2144 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2145 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2146 short_channel_id: 7,
2149 cltv_expiry_delta: (7 << 4) | 1,
2150 htlc_minimum_msat: 0,
2151 htlc_maximum_msat: OptionalField::Absent,
2153 fee_proportional_millionths: 1000000,
2154 excess_data: Vec::new()
2156 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2157 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2158 short_channel_id: 7,
2161 cltv_expiry_delta: (7 << 4) | 2,
2162 htlc_minimum_msat: 0,
2163 htlc_maximum_msat: OptionalField::Absent,
2165 fee_proportional_millionths: 0,
2166 excess_data: Vec::new()
2169 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2171 (secp_ctx, network_graph, net_graph_msg_handler, chain_monitor, logger)
2175 fn simple_route_test() {
2176 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2177 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2178 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2179 let scorer = test_utils::TestScorer::with_penalty(0);
2180 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2181 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2183 // Simple route to 2 via 1
2185 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) {
2186 assert_eq!(err, "Cannot send a payment of 0 msat");
2187 } else { panic!(); }
2189 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2190 assert_eq!(route.paths[0].len(), 2);
2192 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2193 assert_eq!(route.paths[0][0].short_channel_id, 2);
2194 assert_eq!(route.paths[0][0].fee_msat, 100);
2195 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2196 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2197 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2199 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2200 assert_eq!(route.paths[0][1].short_channel_id, 4);
2201 assert_eq!(route.paths[0][1].fee_msat, 100);
2202 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2203 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2204 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2208 fn invalid_first_hop_test() {
2209 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2210 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2211 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2212 let scorer = test_utils::TestScorer::with_penalty(0);
2213 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2214 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2216 // Simple route to 2 via 1
2218 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2220 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2221 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) {
2222 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2223 } else { panic!(); }
2225 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2226 assert_eq!(route.paths[0].len(), 2);
2230 fn htlc_minimum_test() {
2231 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2232 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2233 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2234 let scorer = test_utils::TestScorer::with_penalty(0);
2235 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2236 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2238 // Simple route to 2 via 1
2240 // Disable other paths
2241 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2242 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2243 short_channel_id: 12,
2245 flags: 2, // to disable
2246 cltv_expiry_delta: 0,
2247 htlc_minimum_msat: 0,
2248 htlc_maximum_msat: OptionalField::Absent,
2250 fee_proportional_millionths: 0,
2251 excess_data: Vec::new()
2253 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2254 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2255 short_channel_id: 3,
2257 flags: 2, // to disable
2258 cltv_expiry_delta: 0,
2259 htlc_minimum_msat: 0,
2260 htlc_maximum_msat: OptionalField::Absent,
2262 fee_proportional_millionths: 0,
2263 excess_data: Vec::new()
2265 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2266 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2267 short_channel_id: 13,
2269 flags: 2, // to disable
2270 cltv_expiry_delta: 0,
2271 htlc_minimum_msat: 0,
2272 htlc_maximum_msat: OptionalField::Absent,
2274 fee_proportional_millionths: 0,
2275 excess_data: Vec::new()
2277 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2278 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2279 short_channel_id: 6,
2281 flags: 2, // to disable
2282 cltv_expiry_delta: 0,
2283 htlc_minimum_msat: 0,
2284 htlc_maximum_msat: OptionalField::Absent,
2286 fee_proportional_millionths: 0,
2287 excess_data: Vec::new()
2289 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2290 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2291 short_channel_id: 7,
2293 flags: 2, // to disable
2294 cltv_expiry_delta: 0,
2295 htlc_minimum_msat: 0,
2296 htlc_maximum_msat: OptionalField::Absent,
2298 fee_proportional_millionths: 0,
2299 excess_data: Vec::new()
2302 // Check against amount_to_transfer_over_msat.
2303 // Set minimal HTLC of 200_000_000 msat.
2304 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2305 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2306 short_channel_id: 2,
2309 cltv_expiry_delta: 0,
2310 htlc_minimum_msat: 200_000_000,
2311 htlc_maximum_msat: OptionalField::Absent,
2313 fee_proportional_millionths: 0,
2314 excess_data: Vec::new()
2317 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2319 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2320 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2321 short_channel_id: 4,
2324 cltv_expiry_delta: 0,
2325 htlc_minimum_msat: 0,
2326 htlc_maximum_msat: OptionalField::Present(199_999_999),
2328 fee_proportional_millionths: 0,
2329 excess_data: Vec::new()
2332 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2333 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) {
2334 assert_eq!(err, "Failed to find a path to the given destination");
2335 } else { panic!(); }
2337 // Lift the restriction on the first hop.
2338 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2339 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2340 short_channel_id: 2,
2343 cltv_expiry_delta: 0,
2344 htlc_minimum_msat: 0,
2345 htlc_maximum_msat: OptionalField::Absent,
2347 fee_proportional_millionths: 0,
2348 excess_data: Vec::new()
2351 // A payment above the minimum should pass
2352 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();
2353 assert_eq!(route.paths[0].len(), 2);
2357 fn htlc_minimum_overpay_test() {
2358 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2359 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2360 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2361 let scorer = test_utils::TestScorer::with_penalty(0);
2362 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2363 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2365 // A route to node#2 via two paths.
2366 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2367 // Thus, they can't send 60 without overpaying.
2368 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2369 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2370 short_channel_id: 2,
2373 cltv_expiry_delta: 0,
2374 htlc_minimum_msat: 35_000,
2375 htlc_maximum_msat: OptionalField::Present(40_000),
2377 fee_proportional_millionths: 0,
2378 excess_data: Vec::new()
2380 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2381 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2382 short_channel_id: 12,
2385 cltv_expiry_delta: 0,
2386 htlc_minimum_msat: 35_000,
2387 htlc_maximum_msat: OptionalField::Present(40_000),
2389 fee_proportional_millionths: 0,
2390 excess_data: Vec::new()
2394 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2395 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2396 short_channel_id: 13,
2399 cltv_expiry_delta: 0,
2400 htlc_minimum_msat: 0,
2401 htlc_maximum_msat: OptionalField::Absent,
2403 fee_proportional_millionths: 0,
2404 excess_data: Vec::new()
2406 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2407 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2408 short_channel_id: 4,
2411 cltv_expiry_delta: 0,
2412 htlc_minimum_msat: 0,
2413 htlc_maximum_msat: OptionalField::Absent,
2415 fee_proportional_millionths: 0,
2416 excess_data: Vec::new()
2419 // Disable other paths
2420 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2421 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2422 short_channel_id: 1,
2424 flags: 2, // to disable
2425 cltv_expiry_delta: 0,
2426 htlc_minimum_msat: 0,
2427 htlc_maximum_msat: OptionalField::Absent,
2429 fee_proportional_millionths: 0,
2430 excess_data: Vec::new()
2433 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2434 // Overpay fees to hit htlc_minimum_msat.
2435 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2436 // TODO: this could be better balanced to overpay 10k and not 15k.
2437 assert_eq!(overpaid_fees, 15_000);
2439 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2440 // while taking even more fee to match htlc_minimum_msat.
2441 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2442 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2443 short_channel_id: 12,
2446 cltv_expiry_delta: 0,
2447 htlc_minimum_msat: 65_000,
2448 htlc_maximum_msat: OptionalField::Present(80_000),
2450 fee_proportional_millionths: 0,
2451 excess_data: Vec::new()
2453 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2454 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2455 short_channel_id: 2,
2458 cltv_expiry_delta: 0,
2459 htlc_minimum_msat: 0,
2460 htlc_maximum_msat: OptionalField::Absent,
2462 fee_proportional_millionths: 0,
2463 excess_data: Vec::new()
2465 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2466 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2467 short_channel_id: 4,
2470 cltv_expiry_delta: 0,
2471 htlc_minimum_msat: 0,
2472 htlc_maximum_msat: OptionalField::Absent,
2474 fee_proportional_millionths: 100_000,
2475 excess_data: Vec::new()
2478 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2479 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2480 assert_eq!(route.paths.len(), 1);
2481 assert_eq!(route.paths[0][0].short_channel_id, 12);
2482 let fees = route.paths[0][0].fee_msat;
2483 assert_eq!(fees, 5_000);
2485 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2486 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2487 // the other channel.
2488 assert_eq!(route.paths.len(), 1);
2489 assert_eq!(route.paths[0][0].short_channel_id, 2);
2490 let fees = route.paths[0][0].fee_msat;
2491 assert_eq!(fees, 5_000);
2495 fn disable_channels_test() {
2496 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2497 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2498 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2499 let scorer = test_utils::TestScorer::with_penalty(0);
2500 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2501 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2503 // // Disable channels 4 and 12 by flags=2
2504 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2505 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2506 short_channel_id: 4,
2508 flags: 2, // to disable
2509 cltv_expiry_delta: 0,
2510 htlc_minimum_msat: 0,
2511 htlc_maximum_msat: OptionalField::Absent,
2513 fee_proportional_millionths: 0,
2514 excess_data: Vec::new()
2516 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2517 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2518 short_channel_id: 12,
2520 flags: 2, // to disable
2521 cltv_expiry_delta: 0,
2522 htlc_minimum_msat: 0,
2523 htlc_maximum_msat: OptionalField::Absent,
2525 fee_proportional_millionths: 0,
2526 excess_data: Vec::new()
2529 // If all the channels require some features we don't understand, route should fail
2530 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) {
2531 assert_eq!(err, "Failed to find a path to the given destination");
2532 } else { panic!(); }
2534 // If we specify a channel to node7, that overrides our local channel view and that gets used
2535 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2536 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();
2537 assert_eq!(route.paths[0].len(), 2);
2539 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2540 assert_eq!(route.paths[0][0].short_channel_id, 42);
2541 assert_eq!(route.paths[0][0].fee_msat, 200);
2542 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2543 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2544 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2546 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2547 assert_eq!(route.paths[0][1].short_channel_id, 13);
2548 assert_eq!(route.paths[0][1].fee_msat, 100);
2549 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2550 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2551 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2555 fn disable_node_test() {
2556 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2557 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2558 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2559 let scorer = test_utils::TestScorer::with_penalty(0);
2560 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2561 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2563 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2564 let mut unknown_features = NodeFeatures::known();
2565 unknown_features.set_unknown_feature_required();
2566 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2567 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2568 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2570 // If all nodes require some features we don't understand, route should fail
2571 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) {
2572 assert_eq!(err, "Failed to find a path to the given destination");
2573 } else { panic!(); }
2575 // If we specify a channel to node7, that overrides our local channel view and that gets used
2576 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2577 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();
2578 assert_eq!(route.paths[0].len(), 2);
2580 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2581 assert_eq!(route.paths[0][0].short_channel_id, 42);
2582 assert_eq!(route.paths[0][0].fee_msat, 200);
2583 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2584 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2585 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2587 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2588 assert_eq!(route.paths[0][1].short_channel_id, 13);
2589 assert_eq!(route.paths[0][1].fee_msat, 100);
2590 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2591 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2592 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2594 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2595 // naively) assume that the user checked the feature bits on the invoice, which override
2596 // the node_announcement.
2600 fn our_chans_test() {
2601 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2602 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2603 let scorer = test_utils::TestScorer::with_penalty(0);
2604 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2605 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2607 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2608 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2609 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2610 assert_eq!(route.paths[0].len(), 3);
2612 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2613 assert_eq!(route.paths[0][0].short_channel_id, 2);
2614 assert_eq!(route.paths[0][0].fee_msat, 200);
2615 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2616 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2617 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2619 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2620 assert_eq!(route.paths[0][1].short_channel_id, 4);
2621 assert_eq!(route.paths[0][1].fee_msat, 100);
2622 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2623 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2624 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2626 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2627 assert_eq!(route.paths[0][2].short_channel_id, 3);
2628 assert_eq!(route.paths[0][2].fee_msat, 100);
2629 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2630 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2631 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2633 // If we specify a channel to node7, that overrides our local channel view and that gets used
2634 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2635 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2636 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();
2637 assert_eq!(route.paths[0].len(), 2);
2639 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2640 assert_eq!(route.paths[0][0].short_channel_id, 42);
2641 assert_eq!(route.paths[0][0].fee_msat, 200);
2642 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2643 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2644 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2646 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2647 assert_eq!(route.paths[0][1].short_channel_id, 13);
2648 assert_eq!(route.paths[0][1].fee_msat, 100);
2649 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2650 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2651 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2654 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2655 let zero_fees = RoutingFees {
2657 proportional_millionths: 0,
2659 vec![RouteHint(vec![RouteHintHop {
2660 src_node_id: nodes[3],
2661 short_channel_id: 8,
2663 cltv_expiry_delta: (8 << 4) | 1,
2664 htlc_minimum_msat: None,
2665 htlc_maximum_msat: None,
2667 ]), RouteHint(vec![RouteHintHop {
2668 src_node_id: nodes[4],
2669 short_channel_id: 9,
2672 proportional_millionths: 0,
2674 cltv_expiry_delta: (9 << 4) | 1,
2675 htlc_minimum_msat: None,
2676 htlc_maximum_msat: None,
2677 }]), RouteHint(vec![RouteHintHop {
2678 src_node_id: nodes[5],
2679 short_channel_id: 10,
2681 cltv_expiry_delta: (10 << 4) | 1,
2682 htlc_minimum_msat: None,
2683 htlc_maximum_msat: None,
2687 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2688 let zero_fees = RoutingFees {
2690 proportional_millionths: 0,
2692 vec![RouteHint(vec![RouteHintHop {
2693 src_node_id: nodes[2],
2694 short_channel_id: 5,
2697 proportional_millionths: 0,
2699 cltv_expiry_delta: (5 << 4) | 1,
2700 htlc_minimum_msat: None,
2701 htlc_maximum_msat: None,
2703 src_node_id: nodes[3],
2704 short_channel_id: 8,
2706 cltv_expiry_delta: (8 << 4) | 1,
2707 htlc_minimum_msat: None,
2708 htlc_maximum_msat: None,
2710 ]), RouteHint(vec![RouteHintHop {
2711 src_node_id: nodes[4],
2712 short_channel_id: 9,
2715 proportional_millionths: 0,
2717 cltv_expiry_delta: (9 << 4) | 1,
2718 htlc_minimum_msat: None,
2719 htlc_maximum_msat: None,
2720 }]), RouteHint(vec![RouteHintHop {
2721 src_node_id: nodes[5],
2722 short_channel_id: 10,
2724 cltv_expiry_delta: (10 << 4) | 1,
2725 htlc_minimum_msat: None,
2726 htlc_maximum_msat: None,
2731 fn partial_route_hint_test() {
2732 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2733 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2734 let scorer = test_utils::TestScorer::with_penalty(0);
2735 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2736 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2738 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2739 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2740 // RouteHint may be partially used by the algo to build the best path.
2742 // First check that last hop can't have its source as the payee.
2743 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2744 src_node_id: nodes[6],
2745 short_channel_id: 8,
2748 proportional_millionths: 0,
2750 cltv_expiry_delta: (8 << 4) | 1,
2751 htlc_minimum_msat: None,
2752 htlc_maximum_msat: None,
2755 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2756 invalid_last_hops.push(invalid_last_hop);
2758 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2759 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) {
2760 assert_eq!(err, "Route hint cannot have the payee as the source.");
2761 } else { panic!(); }
2764 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
2765 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2766 assert_eq!(route.paths[0].len(), 5);
2768 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2769 assert_eq!(route.paths[0][0].short_channel_id, 2);
2770 assert_eq!(route.paths[0][0].fee_msat, 100);
2771 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2772 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2773 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2775 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2776 assert_eq!(route.paths[0][1].short_channel_id, 4);
2777 assert_eq!(route.paths[0][1].fee_msat, 0);
2778 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2779 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2780 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2782 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2783 assert_eq!(route.paths[0][2].short_channel_id, 6);
2784 assert_eq!(route.paths[0][2].fee_msat, 0);
2785 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2786 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2787 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2789 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2790 assert_eq!(route.paths[0][3].short_channel_id, 11);
2791 assert_eq!(route.paths[0][3].fee_msat, 0);
2792 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2793 // If we have a peer in the node map, we'll use their features here since we don't have
2794 // a way of figuring out their features from the invoice:
2795 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2796 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2798 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2799 assert_eq!(route.paths[0][4].short_channel_id, 8);
2800 assert_eq!(route.paths[0][4].fee_msat, 100);
2801 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2802 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2803 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2806 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2807 let zero_fees = RoutingFees {
2809 proportional_millionths: 0,
2811 vec![RouteHint(vec![RouteHintHop {
2812 src_node_id: nodes[3],
2813 short_channel_id: 8,
2815 cltv_expiry_delta: (8 << 4) | 1,
2816 htlc_minimum_msat: None,
2817 htlc_maximum_msat: None,
2818 }]), RouteHint(vec![
2820 ]), RouteHint(vec![RouteHintHop {
2821 src_node_id: nodes[5],
2822 short_channel_id: 10,
2824 cltv_expiry_delta: (10 << 4) | 1,
2825 htlc_minimum_msat: None,
2826 htlc_maximum_msat: None,
2831 fn ignores_empty_last_hops_test() {
2832 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2833 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2834 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
2835 let scorer = test_utils::TestScorer::with_penalty(0);
2836 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2837 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2839 // Test handling of an empty RouteHint passed in Invoice.
2841 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2842 assert_eq!(route.paths[0].len(), 5);
2844 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2845 assert_eq!(route.paths[0][0].short_channel_id, 2);
2846 assert_eq!(route.paths[0][0].fee_msat, 100);
2847 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2848 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2849 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2851 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2852 assert_eq!(route.paths[0][1].short_channel_id, 4);
2853 assert_eq!(route.paths[0][1].fee_msat, 0);
2854 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2855 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2856 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2858 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2859 assert_eq!(route.paths[0][2].short_channel_id, 6);
2860 assert_eq!(route.paths[0][2].fee_msat, 0);
2861 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2862 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2863 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2865 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2866 assert_eq!(route.paths[0][3].short_channel_id, 11);
2867 assert_eq!(route.paths[0][3].fee_msat, 0);
2868 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2869 // If we have a peer in the node map, we'll use their features here since we don't have
2870 // a way of figuring out their features from the invoice:
2871 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2872 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2874 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2875 assert_eq!(route.paths[0][4].short_channel_id, 8);
2876 assert_eq!(route.paths[0][4].fee_msat, 100);
2877 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2878 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2879 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2882 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
2884 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
2885 let zero_fees = RoutingFees {
2887 proportional_millionths: 0,
2889 vec![RouteHint(vec![RouteHintHop {
2890 src_node_id: hint_hops[0],
2891 short_channel_id: 0xff00,
2894 proportional_millionths: 0,
2896 cltv_expiry_delta: (5 << 4) | 1,
2897 htlc_minimum_msat: None,
2898 htlc_maximum_msat: None,
2900 src_node_id: hint_hops[1],
2901 short_channel_id: 0xff01,
2903 cltv_expiry_delta: (8 << 4) | 1,
2904 htlc_minimum_msat: None,
2905 htlc_maximum_msat: None,
2910 fn multi_hint_last_hops_test() {
2911 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2912 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2913 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
2914 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2915 let scorer = test_utils::TestScorer::with_penalty(0);
2916 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2917 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2918 // Test through channels 2, 3, 0xff00, 0xff01.
2919 // Test shows that multiple hop hints are considered.
2921 // Disabling channels 6 & 7 by flags=2
2922 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2923 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2924 short_channel_id: 6,
2926 flags: 2, // to disable
2927 cltv_expiry_delta: 0,
2928 htlc_minimum_msat: 0,
2929 htlc_maximum_msat: OptionalField::Absent,
2931 fee_proportional_millionths: 0,
2932 excess_data: Vec::new()
2934 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2935 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2936 short_channel_id: 7,
2938 flags: 2, // to disable
2939 cltv_expiry_delta: 0,
2940 htlc_minimum_msat: 0,
2941 htlc_maximum_msat: OptionalField::Absent,
2943 fee_proportional_millionths: 0,
2944 excess_data: Vec::new()
2947 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2948 assert_eq!(route.paths[0].len(), 4);
2950 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2951 assert_eq!(route.paths[0][0].short_channel_id, 2);
2952 assert_eq!(route.paths[0][0].fee_msat, 200);
2953 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2954 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2955 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2957 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2958 assert_eq!(route.paths[0][1].short_channel_id, 4);
2959 assert_eq!(route.paths[0][1].fee_msat, 100);
2960 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2961 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2962 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2964 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
2965 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
2966 assert_eq!(route.paths[0][2].fee_msat, 0);
2967 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2968 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
2969 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2971 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2972 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
2973 assert_eq!(route.paths[0][3].fee_msat, 100);
2974 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2975 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
2976 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2980 fn private_multi_hint_last_hops_test() {
2981 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2982 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2984 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
2985 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
2987 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
2988 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2989 let scorer = test_utils::TestScorer::with_penalty(0);
2990 // Test through channels 2, 3, 0xff00, 0xff01.
2991 // Test shows that multiple hop hints are considered.
2993 // Disabling channels 6 & 7 by flags=2
2994 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2996 short_channel_id: 6,
2998 flags: 2, // to disable
2999 cltv_expiry_delta: 0,
3000 htlc_minimum_msat: 0,
3001 htlc_maximum_msat: OptionalField::Absent,
3003 fee_proportional_millionths: 0,
3004 excess_data: Vec::new()
3006 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3008 short_channel_id: 7,
3010 flags: 2, // to disable
3011 cltv_expiry_delta: 0,
3012 htlc_minimum_msat: 0,
3013 htlc_maximum_msat: OptionalField::Absent,
3015 fee_proportional_millionths: 0,
3016 excess_data: Vec::new()
3019 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3020 assert_eq!(route.paths[0].len(), 4);
3022 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3023 assert_eq!(route.paths[0][0].short_channel_id, 2);
3024 assert_eq!(route.paths[0][0].fee_msat, 200);
3025 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3026 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3027 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3029 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3030 assert_eq!(route.paths[0][1].short_channel_id, 4);
3031 assert_eq!(route.paths[0][1].fee_msat, 100);
3032 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3033 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3034 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3036 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
3037 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3038 assert_eq!(route.paths[0][2].fee_msat, 0);
3039 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3040 assert_eq!(route.paths[0][2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3041 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3043 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3044 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3045 assert_eq!(route.paths[0][3].fee_msat, 100);
3046 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3047 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3048 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3051 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3052 let zero_fees = RoutingFees {
3054 proportional_millionths: 0,
3056 vec![RouteHint(vec![RouteHintHop {
3057 src_node_id: nodes[4],
3058 short_channel_id: 11,
3060 cltv_expiry_delta: (11 << 4) | 1,
3061 htlc_minimum_msat: None,
3062 htlc_maximum_msat: None,
3064 src_node_id: nodes[3],
3065 short_channel_id: 8,
3067 cltv_expiry_delta: (8 << 4) | 1,
3068 htlc_minimum_msat: None,
3069 htlc_maximum_msat: None,
3070 }]), RouteHint(vec![RouteHintHop {
3071 src_node_id: nodes[4],
3072 short_channel_id: 9,
3075 proportional_millionths: 0,
3077 cltv_expiry_delta: (9 << 4) | 1,
3078 htlc_minimum_msat: None,
3079 htlc_maximum_msat: None,
3080 }]), RouteHint(vec![RouteHintHop {
3081 src_node_id: nodes[5],
3082 short_channel_id: 10,
3084 cltv_expiry_delta: (10 << 4) | 1,
3085 htlc_minimum_msat: None,
3086 htlc_maximum_msat: None,
3091 fn last_hops_with_public_channel_test() {
3092 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3093 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3094 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3095 let scorer = test_utils::TestScorer::with_penalty(0);
3096 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3097 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3098 // This test shows that public routes can be present in the invoice
3099 // which would be handled in the same manner.
3101 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3102 assert_eq!(route.paths[0].len(), 5);
3104 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3105 assert_eq!(route.paths[0][0].short_channel_id, 2);
3106 assert_eq!(route.paths[0][0].fee_msat, 100);
3107 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3108 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3109 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3111 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3112 assert_eq!(route.paths[0][1].short_channel_id, 4);
3113 assert_eq!(route.paths[0][1].fee_msat, 0);
3114 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3115 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3116 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3118 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3119 assert_eq!(route.paths[0][2].short_channel_id, 6);
3120 assert_eq!(route.paths[0][2].fee_msat, 0);
3121 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3122 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3123 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3125 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3126 assert_eq!(route.paths[0][3].short_channel_id, 11);
3127 assert_eq!(route.paths[0][3].fee_msat, 0);
3128 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3129 // If we have a peer in the node map, we'll use their features here since we don't have
3130 // a way of figuring out their features from the invoice:
3131 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3132 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3134 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3135 assert_eq!(route.paths[0][4].short_channel_id, 8);
3136 assert_eq!(route.paths[0][4].fee_msat, 100);
3137 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3138 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3139 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3143 fn our_chans_last_hop_connect_test() {
3144 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3145 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3146 let scorer = test_utils::TestScorer::with_penalty(0);
3147 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3148 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3150 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3151 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3152 let mut last_hops = last_hops(&nodes);
3153 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3154 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();
3155 assert_eq!(route.paths[0].len(), 2);
3157 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3158 assert_eq!(route.paths[0][0].short_channel_id, 42);
3159 assert_eq!(route.paths[0][0].fee_msat, 0);
3160 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3161 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3162 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3164 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3165 assert_eq!(route.paths[0][1].short_channel_id, 8);
3166 assert_eq!(route.paths[0][1].fee_msat, 100);
3167 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3168 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3169 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3171 last_hops[0].0[0].fees.base_msat = 1000;
3173 // Revert to via 6 as the fee on 8 goes up
3174 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3175 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3176 assert_eq!(route.paths[0].len(), 4);
3178 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3179 assert_eq!(route.paths[0][0].short_channel_id, 2);
3180 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3181 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3182 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3183 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3185 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3186 assert_eq!(route.paths[0][1].short_channel_id, 4);
3187 assert_eq!(route.paths[0][1].fee_msat, 100);
3188 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3189 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3190 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3192 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3193 assert_eq!(route.paths[0][2].short_channel_id, 7);
3194 assert_eq!(route.paths[0][2].fee_msat, 0);
3195 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3196 // If we have a peer in the node map, we'll use their features here since we don't have
3197 // a way of figuring out their features from the invoice:
3198 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3199 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3201 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3202 assert_eq!(route.paths[0][3].short_channel_id, 10);
3203 assert_eq!(route.paths[0][3].fee_msat, 100);
3204 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3205 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3206 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3208 // ...but still use 8 for larger payments as 6 has a variable feerate
3209 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3210 assert_eq!(route.paths[0].len(), 5);
3212 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3213 assert_eq!(route.paths[0][0].short_channel_id, 2);
3214 assert_eq!(route.paths[0][0].fee_msat, 3000);
3215 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3216 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3217 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3219 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3220 assert_eq!(route.paths[0][1].short_channel_id, 4);
3221 assert_eq!(route.paths[0][1].fee_msat, 0);
3222 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3223 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3224 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3226 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3227 assert_eq!(route.paths[0][2].short_channel_id, 6);
3228 assert_eq!(route.paths[0][2].fee_msat, 0);
3229 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3230 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3231 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3233 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3234 assert_eq!(route.paths[0][3].short_channel_id, 11);
3235 assert_eq!(route.paths[0][3].fee_msat, 1000);
3236 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3237 // If we have a peer in the node map, we'll use their features here since we don't have
3238 // a way of figuring out their features from the invoice:
3239 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3240 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3242 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3243 assert_eq!(route.paths[0][4].short_channel_id, 8);
3244 assert_eq!(route.paths[0][4].fee_msat, 2000);
3245 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3246 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3247 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3250 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> {
3251 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3252 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3253 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3255 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3256 let last_hops = RouteHint(vec![RouteHintHop {
3257 src_node_id: middle_node_id,
3258 short_channel_id: 8,
3261 proportional_millionths: last_hop_fee_prop,
3263 cltv_expiry_delta: (8 << 4) | 1,
3264 htlc_minimum_msat: None,
3265 htlc_maximum_msat: last_hop_htlc_max,
3267 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3268 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3269 let scorer = test_utils::TestScorer::with_penalty(0);
3270 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3271 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3272 get_route(&source_node_id, &payment_params, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()).read_only(),
3273 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes)
3277 fn unannounced_path_test() {
3278 // We should be able to send a payment to a destination without any help of a routing graph
3279 // if we have a channel with a common counterparty that appears in the first and last hop
3281 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3283 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3284 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3285 assert_eq!(route.paths[0].len(), 2);
3287 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3288 assert_eq!(route.paths[0][0].short_channel_id, 42);
3289 assert_eq!(route.paths[0][0].fee_msat, 1001);
3290 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3291 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3292 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3294 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3295 assert_eq!(route.paths[0][1].short_channel_id, 8);
3296 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3297 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3298 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3299 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3303 fn overflow_unannounced_path_test_liquidity_underflow() {
3304 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3305 // the last-hop had a fee which overflowed a u64, we'd panic.
3306 // This was due to us adding the first-hop from us unconditionally, causing us to think
3307 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3308 // In this test, we previously hit a subtraction underflow due to having less available
3309 // liquidity at the last hop than 0.
3310 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());
3314 fn overflow_unannounced_path_test_feerate_overflow() {
3315 // This tests for the same case as above, except instead of hitting a subtraction
3316 // underflow, we hit a case where the fee charged at a hop overflowed.
3317 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());
3321 fn available_amount_while_routing_test() {
3322 // Tests whether we choose the correct available channel amount while routing.
3324 let (secp_ctx, network_graph, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
3325 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3326 let scorer = test_utils::TestScorer::with_penalty(0);
3327 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3328 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3329 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3331 // We will use a simple single-path route from
3332 // our node to node2 via node0: channels {1, 3}.
3334 // First disable all other paths.
3335 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3336 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3337 short_channel_id: 2,
3340 cltv_expiry_delta: 0,
3341 htlc_minimum_msat: 0,
3342 htlc_maximum_msat: OptionalField::Present(100_000),
3344 fee_proportional_millionths: 0,
3345 excess_data: Vec::new()
3347 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3348 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3349 short_channel_id: 12,
3352 cltv_expiry_delta: 0,
3353 htlc_minimum_msat: 0,
3354 htlc_maximum_msat: OptionalField::Present(100_000),
3356 fee_proportional_millionths: 0,
3357 excess_data: Vec::new()
3360 // Make the first channel (#1) very permissive,
3361 // and we will be testing all limits on the second channel.
3362 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3363 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3364 short_channel_id: 1,
3367 cltv_expiry_delta: 0,
3368 htlc_minimum_msat: 0,
3369 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3371 fee_proportional_millionths: 0,
3372 excess_data: Vec::new()
3375 // First, let's see if routing works if we have absolutely no idea about the available amount.
3376 // In this case, it should be set to 250_000 sats.
3377 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3378 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3379 short_channel_id: 3,
3382 cltv_expiry_delta: 0,
3383 htlc_minimum_msat: 0,
3384 htlc_maximum_msat: OptionalField::Absent,
3386 fee_proportional_millionths: 0,
3387 excess_data: Vec::new()
3391 // Attempt to route more than available results in a failure.
3392 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3393 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3394 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3395 } else { panic!(); }
3399 // Now, attempt to route an exact amount we have should be fine.
3400 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();
3401 assert_eq!(route.paths.len(), 1);
3402 let path = route.paths.last().unwrap();
3403 assert_eq!(path.len(), 2);
3404 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3405 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3408 // Check that setting outbound_capacity_msat in first_hops limits the channels.
3409 // Disable channel #1 and use another first hop.
3410 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3411 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3412 short_channel_id: 1,
3415 cltv_expiry_delta: 0,
3416 htlc_minimum_msat: 0,
3417 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3419 fee_proportional_millionths: 0,
3420 excess_data: Vec::new()
3423 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
3424 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3427 // Attempt to route more than available results in a failure.
3428 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3429 &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) {
3430 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3431 } else { panic!(); }
3435 // Now, attempt to route an exact amount we have should be fine.
3436 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();
3437 assert_eq!(route.paths.len(), 1);
3438 let path = route.paths.last().unwrap();
3439 assert_eq!(path.len(), 2);
3440 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3441 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3444 // Enable channel #1 back.
3445 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3446 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3447 short_channel_id: 1,
3450 cltv_expiry_delta: 0,
3451 htlc_minimum_msat: 0,
3452 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3454 fee_proportional_millionths: 0,
3455 excess_data: Vec::new()
3459 // Now let's see if routing works if we know only htlc_maximum_msat.
3460 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3461 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3462 short_channel_id: 3,
3465 cltv_expiry_delta: 0,
3466 htlc_minimum_msat: 0,
3467 htlc_maximum_msat: OptionalField::Present(15_000),
3469 fee_proportional_millionths: 0,
3470 excess_data: Vec::new()
3474 // Attempt to route more than available results in a failure.
3475 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3476 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3477 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3478 } else { panic!(); }
3482 // Now, attempt to route an exact amount we have should be fine.
3483 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3484 assert_eq!(route.paths.len(), 1);
3485 let path = route.paths.last().unwrap();
3486 assert_eq!(path.len(), 2);
3487 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3488 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3491 // Now let's see if routing works if we know only capacity from the UTXO.
3493 // We can't change UTXO capacity on the fly, so we'll disable
3494 // the existing channel and add another one with the capacity we need.
3495 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3496 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3497 short_channel_id: 3,
3500 cltv_expiry_delta: 0,
3501 htlc_minimum_msat: 0,
3502 htlc_maximum_msat: OptionalField::Absent,
3504 fee_proportional_millionths: 0,
3505 excess_data: Vec::new()
3508 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3509 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3510 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3511 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3512 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3514 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3515 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
3517 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3518 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3519 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3520 short_channel_id: 333,
3523 cltv_expiry_delta: (3 << 4) | 1,
3524 htlc_minimum_msat: 0,
3525 htlc_maximum_msat: OptionalField::Absent,
3527 fee_proportional_millionths: 0,
3528 excess_data: Vec::new()
3530 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3531 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3532 short_channel_id: 333,
3535 cltv_expiry_delta: (3 << 4) | 2,
3536 htlc_minimum_msat: 0,
3537 htlc_maximum_msat: OptionalField::Absent,
3539 fee_proportional_millionths: 0,
3540 excess_data: Vec::new()
3544 // Attempt to route more than available results in a failure.
3545 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3546 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3547 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3548 } else { panic!(); }
3552 // Now, attempt to route an exact amount we have should be fine.
3553 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3554 assert_eq!(route.paths.len(), 1);
3555 let path = route.paths.last().unwrap();
3556 assert_eq!(path.len(), 2);
3557 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3558 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3561 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3562 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3563 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3564 short_channel_id: 333,
3567 cltv_expiry_delta: 0,
3568 htlc_minimum_msat: 0,
3569 htlc_maximum_msat: OptionalField::Present(10_000),
3571 fee_proportional_millionths: 0,
3572 excess_data: Vec::new()
3576 // Attempt to route more than available results in a failure.
3577 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3578 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3579 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3580 } else { panic!(); }
3584 // Now, attempt to route an exact amount we have should be fine.
3585 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3586 assert_eq!(route.paths.len(), 1);
3587 let path = route.paths.last().unwrap();
3588 assert_eq!(path.len(), 2);
3589 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3590 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3595 fn available_liquidity_last_hop_test() {
3596 // Check that available liquidity properly limits the path even when only
3597 // one of the latter hops is limited.
3598 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3599 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3600 let scorer = test_utils::TestScorer::with_penalty(0);
3601 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3602 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3603 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3605 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3606 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3607 // Total capacity: 50 sats.
3609 // Disable other potential paths.
3610 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3611 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3612 short_channel_id: 2,
3615 cltv_expiry_delta: 0,
3616 htlc_minimum_msat: 0,
3617 htlc_maximum_msat: OptionalField::Present(100_000),
3619 fee_proportional_millionths: 0,
3620 excess_data: Vec::new()
3622 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3623 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3624 short_channel_id: 7,
3627 cltv_expiry_delta: 0,
3628 htlc_minimum_msat: 0,
3629 htlc_maximum_msat: OptionalField::Present(100_000),
3631 fee_proportional_millionths: 0,
3632 excess_data: Vec::new()
3637 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3638 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3639 short_channel_id: 12,
3642 cltv_expiry_delta: 0,
3643 htlc_minimum_msat: 0,
3644 htlc_maximum_msat: OptionalField::Present(100_000),
3646 fee_proportional_millionths: 0,
3647 excess_data: Vec::new()
3649 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3650 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3651 short_channel_id: 13,
3654 cltv_expiry_delta: 0,
3655 htlc_minimum_msat: 0,
3656 htlc_maximum_msat: OptionalField::Present(100_000),
3658 fee_proportional_millionths: 0,
3659 excess_data: Vec::new()
3662 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3663 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3664 short_channel_id: 6,
3667 cltv_expiry_delta: 0,
3668 htlc_minimum_msat: 0,
3669 htlc_maximum_msat: OptionalField::Present(50_000),
3671 fee_proportional_millionths: 0,
3672 excess_data: Vec::new()
3674 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3675 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3676 short_channel_id: 11,
3679 cltv_expiry_delta: 0,
3680 htlc_minimum_msat: 0,
3681 htlc_maximum_msat: OptionalField::Present(100_000),
3683 fee_proportional_millionths: 0,
3684 excess_data: Vec::new()
3687 // Attempt to route more than available results in a failure.
3688 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3689 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3690 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3691 } else { panic!(); }
3695 // Now, attempt to route 49 sats (just a bit below the capacity).
3696 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3697 assert_eq!(route.paths.len(), 1);
3698 let mut total_amount_paid_msat = 0;
3699 for path in &route.paths {
3700 assert_eq!(path.len(), 4);
3701 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3702 total_amount_paid_msat += path.last().unwrap().fee_msat;
3704 assert_eq!(total_amount_paid_msat, 49_000);
3708 // Attempt to route an exact amount is also fine
3709 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3710 assert_eq!(route.paths.len(), 1);
3711 let mut total_amount_paid_msat = 0;
3712 for path in &route.paths {
3713 assert_eq!(path.len(), 4);
3714 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3715 total_amount_paid_msat += path.last().unwrap().fee_msat;
3717 assert_eq!(total_amount_paid_msat, 50_000);
3722 fn ignore_fee_first_hop_test() {
3723 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3724 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3725 let scorer = test_utils::TestScorer::with_penalty(0);
3726 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3727 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3728 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3730 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3731 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3732 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3733 short_channel_id: 1,
3736 cltv_expiry_delta: 0,
3737 htlc_minimum_msat: 0,
3738 htlc_maximum_msat: OptionalField::Present(100_000),
3739 fee_base_msat: 1_000_000,
3740 fee_proportional_millionths: 0,
3741 excess_data: Vec::new()
3743 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3744 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3745 short_channel_id: 3,
3748 cltv_expiry_delta: 0,
3749 htlc_minimum_msat: 0,
3750 htlc_maximum_msat: OptionalField::Present(50_000),
3752 fee_proportional_millionths: 0,
3753 excess_data: Vec::new()
3757 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3758 assert_eq!(route.paths.len(), 1);
3759 let mut total_amount_paid_msat = 0;
3760 for path in &route.paths {
3761 assert_eq!(path.len(), 2);
3762 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3763 total_amount_paid_msat += path.last().unwrap().fee_msat;
3765 assert_eq!(total_amount_paid_msat, 50_000);
3770 fn simple_mpp_route_test() {
3771 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3772 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3773 let scorer = test_utils::TestScorer::with_penalty(0);
3774 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3775 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3776 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3778 // We need a route consisting of 3 paths:
3779 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3780 // To achieve this, the amount being transferred should be around
3781 // the total capacity of these 3 paths.
3783 // First, we set limits on these (previously unlimited) channels.
3784 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3786 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3787 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3788 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3789 short_channel_id: 1,
3792 cltv_expiry_delta: 0,
3793 htlc_minimum_msat: 0,
3794 htlc_maximum_msat: OptionalField::Present(100_000),
3796 fee_proportional_millionths: 0,
3797 excess_data: Vec::new()
3799 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3800 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3801 short_channel_id: 3,
3804 cltv_expiry_delta: 0,
3805 htlc_minimum_msat: 0,
3806 htlc_maximum_msat: OptionalField::Present(50_000),
3808 fee_proportional_millionths: 0,
3809 excess_data: Vec::new()
3812 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3813 // (total limit 60).
3814 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3815 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3816 short_channel_id: 12,
3819 cltv_expiry_delta: 0,
3820 htlc_minimum_msat: 0,
3821 htlc_maximum_msat: OptionalField::Present(60_000),
3823 fee_proportional_millionths: 0,
3824 excess_data: Vec::new()
3826 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3827 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3828 short_channel_id: 13,
3831 cltv_expiry_delta: 0,
3832 htlc_minimum_msat: 0,
3833 htlc_maximum_msat: OptionalField::Present(60_000),
3835 fee_proportional_millionths: 0,
3836 excess_data: Vec::new()
3839 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3840 // (total capacity 180 sats).
3841 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3842 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3843 short_channel_id: 2,
3846 cltv_expiry_delta: 0,
3847 htlc_minimum_msat: 0,
3848 htlc_maximum_msat: OptionalField::Present(200_000),
3850 fee_proportional_millionths: 0,
3851 excess_data: Vec::new()
3853 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3854 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3855 short_channel_id: 4,
3858 cltv_expiry_delta: 0,
3859 htlc_minimum_msat: 0,
3860 htlc_maximum_msat: OptionalField::Present(180_000),
3862 fee_proportional_millionths: 0,
3863 excess_data: Vec::new()
3867 // Attempt to route more than available results in a failure.
3868 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3869 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3870 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3871 } else { panic!(); }
3875 // Now, attempt to route 250 sats (just a bit below the capacity).
3876 // Our algorithm should provide us with these 3 paths.
3877 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3878 assert_eq!(route.paths.len(), 3);
3879 let mut total_amount_paid_msat = 0;
3880 for path in &route.paths {
3881 assert_eq!(path.len(), 2);
3882 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3883 total_amount_paid_msat += path.last().unwrap().fee_msat;
3885 assert_eq!(total_amount_paid_msat, 250_000);
3889 // Attempt to route an exact amount is also fine
3890 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3891 assert_eq!(route.paths.len(), 3);
3892 let mut total_amount_paid_msat = 0;
3893 for path in &route.paths {
3894 assert_eq!(path.len(), 2);
3895 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3896 total_amount_paid_msat += path.last().unwrap().fee_msat;
3898 assert_eq!(total_amount_paid_msat, 290_000);
3903 fn long_mpp_route_test() {
3904 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3905 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3906 let scorer = test_utils::TestScorer::with_penalty(0);
3907 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3908 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3909 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3911 // We need a route consisting of 3 paths:
3912 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3913 // Note that these paths overlap (channels 5, 12, 13).
3914 // We will route 300 sats.
3915 // Each path will have 100 sats capacity, those channels which
3916 // are used twice will have 200 sats capacity.
3918 // Disable other potential paths.
3919 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3920 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3921 short_channel_id: 2,
3924 cltv_expiry_delta: 0,
3925 htlc_minimum_msat: 0,
3926 htlc_maximum_msat: OptionalField::Present(100_000),
3928 fee_proportional_millionths: 0,
3929 excess_data: Vec::new()
3931 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3932 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3933 short_channel_id: 7,
3936 cltv_expiry_delta: 0,
3937 htlc_minimum_msat: 0,
3938 htlc_maximum_msat: OptionalField::Present(100_000),
3940 fee_proportional_millionths: 0,
3941 excess_data: Vec::new()
3944 // Path via {node0, node2} is channels {1, 3, 5}.
3945 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3946 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3947 short_channel_id: 1,
3950 cltv_expiry_delta: 0,
3951 htlc_minimum_msat: 0,
3952 htlc_maximum_msat: OptionalField::Present(100_000),
3954 fee_proportional_millionths: 0,
3955 excess_data: Vec::new()
3957 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3958 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3959 short_channel_id: 3,
3962 cltv_expiry_delta: 0,
3963 htlc_minimum_msat: 0,
3964 htlc_maximum_msat: OptionalField::Present(100_000),
3966 fee_proportional_millionths: 0,
3967 excess_data: Vec::new()
3970 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3971 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3972 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3973 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3974 short_channel_id: 5,
3977 cltv_expiry_delta: 0,
3978 htlc_minimum_msat: 0,
3979 htlc_maximum_msat: OptionalField::Present(200_000),
3981 fee_proportional_millionths: 0,
3982 excess_data: Vec::new()
3985 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3986 // Add 100 sats to the capacities of {12, 13}, because these channels
3987 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3988 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3989 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3990 short_channel_id: 12,
3993 cltv_expiry_delta: 0,
3994 htlc_minimum_msat: 0,
3995 htlc_maximum_msat: OptionalField::Present(200_000),
3997 fee_proportional_millionths: 0,
3998 excess_data: Vec::new()
4000 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4001 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4002 short_channel_id: 13,
4005 cltv_expiry_delta: 0,
4006 htlc_minimum_msat: 0,
4007 htlc_maximum_msat: OptionalField::Present(200_000),
4009 fee_proportional_millionths: 0,
4010 excess_data: Vec::new()
4013 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4014 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4015 short_channel_id: 6,
4018 cltv_expiry_delta: 0,
4019 htlc_minimum_msat: 0,
4020 htlc_maximum_msat: OptionalField::Present(100_000),
4022 fee_proportional_millionths: 0,
4023 excess_data: Vec::new()
4025 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4026 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4027 short_channel_id: 11,
4030 cltv_expiry_delta: 0,
4031 htlc_minimum_msat: 0,
4032 htlc_maximum_msat: OptionalField::Present(100_000),
4034 fee_proportional_millionths: 0,
4035 excess_data: Vec::new()
4038 // Path via {node7, node2} is channels {12, 13, 5}.
4039 // We already limited them to 200 sats (they are used twice for 100 sats).
4040 // Nothing to do here.
4043 // Attempt to route more than available results in a failure.
4044 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4045 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4046 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4047 } else { panic!(); }
4051 // Now, attempt to route 300 sats (exact amount we can route).
4052 // Our algorithm should provide us with these 3 paths, 100 sats each.
4053 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4054 assert_eq!(route.paths.len(), 3);
4056 let mut total_amount_paid_msat = 0;
4057 for path in &route.paths {
4058 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4059 total_amount_paid_msat += path.last().unwrap().fee_msat;
4061 assert_eq!(total_amount_paid_msat, 300_000);
4067 fn mpp_cheaper_route_test() {
4068 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4069 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4070 let scorer = test_utils::TestScorer::with_penalty(0);
4071 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4072 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4073 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4075 // This test checks that if we have two cheaper paths and one more expensive path,
4076 // so that liquidity-wise any 2 of 3 combination is sufficient,
4077 // two cheaper paths will be taken.
4078 // These paths have equal available liquidity.
4080 // We need a combination of 3 paths:
4081 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4082 // Note that these paths overlap (channels 5, 12, 13).
4083 // Each path will have 100 sats capacity, those channels which
4084 // are used twice will have 200 sats capacity.
4086 // Disable other potential paths.
4087 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4088 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4089 short_channel_id: 2,
4092 cltv_expiry_delta: 0,
4093 htlc_minimum_msat: 0,
4094 htlc_maximum_msat: OptionalField::Present(100_000),
4096 fee_proportional_millionths: 0,
4097 excess_data: Vec::new()
4099 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4100 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4101 short_channel_id: 7,
4104 cltv_expiry_delta: 0,
4105 htlc_minimum_msat: 0,
4106 htlc_maximum_msat: OptionalField::Present(100_000),
4108 fee_proportional_millionths: 0,
4109 excess_data: Vec::new()
4112 // Path via {node0, node2} is channels {1, 3, 5}.
4113 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4114 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4115 short_channel_id: 1,
4118 cltv_expiry_delta: 0,
4119 htlc_minimum_msat: 0,
4120 htlc_maximum_msat: OptionalField::Present(100_000),
4122 fee_proportional_millionths: 0,
4123 excess_data: Vec::new()
4125 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4126 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4127 short_channel_id: 3,
4130 cltv_expiry_delta: 0,
4131 htlc_minimum_msat: 0,
4132 htlc_maximum_msat: OptionalField::Present(100_000),
4134 fee_proportional_millionths: 0,
4135 excess_data: Vec::new()
4138 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4139 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4140 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4141 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4142 short_channel_id: 5,
4145 cltv_expiry_delta: 0,
4146 htlc_minimum_msat: 0,
4147 htlc_maximum_msat: OptionalField::Present(200_000),
4149 fee_proportional_millionths: 0,
4150 excess_data: Vec::new()
4153 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4154 // Add 100 sats to the capacities of {12, 13}, because these channels
4155 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4156 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4157 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4158 short_channel_id: 12,
4161 cltv_expiry_delta: 0,
4162 htlc_minimum_msat: 0,
4163 htlc_maximum_msat: OptionalField::Present(200_000),
4165 fee_proportional_millionths: 0,
4166 excess_data: Vec::new()
4168 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4169 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4170 short_channel_id: 13,
4173 cltv_expiry_delta: 0,
4174 htlc_minimum_msat: 0,
4175 htlc_maximum_msat: OptionalField::Present(200_000),
4177 fee_proportional_millionths: 0,
4178 excess_data: Vec::new()
4181 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4182 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4183 short_channel_id: 6,
4186 cltv_expiry_delta: 0,
4187 htlc_minimum_msat: 0,
4188 htlc_maximum_msat: OptionalField::Present(100_000),
4189 fee_base_msat: 1_000,
4190 fee_proportional_millionths: 0,
4191 excess_data: Vec::new()
4193 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4194 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4195 short_channel_id: 11,
4198 cltv_expiry_delta: 0,
4199 htlc_minimum_msat: 0,
4200 htlc_maximum_msat: OptionalField::Present(100_000),
4202 fee_proportional_millionths: 0,
4203 excess_data: Vec::new()
4206 // Path via {node7, node2} is channels {12, 13, 5}.
4207 // We already limited them to 200 sats (they are used twice for 100 sats).
4208 // Nothing to do here.
4211 // Now, attempt to route 180 sats.
4212 // Our algorithm should provide us with these 2 paths.
4213 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4214 assert_eq!(route.paths.len(), 2);
4216 let mut total_value_transferred_msat = 0;
4217 let mut total_paid_msat = 0;
4218 for path in &route.paths {
4219 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4220 total_value_transferred_msat += path.last().unwrap().fee_msat;
4222 total_paid_msat += hop.fee_msat;
4225 // If we paid fee, this would be higher.
4226 assert_eq!(total_value_transferred_msat, 180_000);
4227 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4228 assert_eq!(total_fees_paid, 0);
4233 fn fees_on_mpp_route_test() {
4234 // This test makes sure that MPP algorithm properly takes into account
4235 // fees charged on the channels, by making the fees impactful:
4236 // if the fee is not properly accounted for, the behavior is different.
4237 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4238 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4239 let scorer = test_utils::TestScorer::with_penalty(0);
4240 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4241 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4242 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4244 // We need a route consisting of 2 paths:
4245 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4246 // We will route 200 sats, Each path will have 100 sats capacity.
4248 // This test is not particularly stable: e.g.,
4249 // there's a way to route via {node0, node2, node4}.
4250 // It works while pathfinding is deterministic, but can be broken otherwise.
4251 // It's fine to ignore this concern for now.
4253 // Disable other potential paths.
4254 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4255 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4256 short_channel_id: 2,
4259 cltv_expiry_delta: 0,
4260 htlc_minimum_msat: 0,
4261 htlc_maximum_msat: OptionalField::Present(100_000),
4263 fee_proportional_millionths: 0,
4264 excess_data: Vec::new()
4267 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4268 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4269 short_channel_id: 7,
4272 cltv_expiry_delta: 0,
4273 htlc_minimum_msat: 0,
4274 htlc_maximum_msat: OptionalField::Present(100_000),
4276 fee_proportional_millionths: 0,
4277 excess_data: Vec::new()
4280 // Path via {node0, node2} is channels {1, 3, 5}.
4281 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4282 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4283 short_channel_id: 1,
4286 cltv_expiry_delta: 0,
4287 htlc_minimum_msat: 0,
4288 htlc_maximum_msat: OptionalField::Present(100_000),
4290 fee_proportional_millionths: 0,
4291 excess_data: Vec::new()
4293 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4294 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4295 short_channel_id: 3,
4298 cltv_expiry_delta: 0,
4299 htlc_minimum_msat: 0,
4300 htlc_maximum_msat: OptionalField::Present(100_000),
4302 fee_proportional_millionths: 0,
4303 excess_data: Vec::new()
4306 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4307 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4308 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4309 short_channel_id: 5,
4312 cltv_expiry_delta: 0,
4313 htlc_minimum_msat: 0,
4314 htlc_maximum_msat: OptionalField::Present(100_000),
4316 fee_proportional_millionths: 0,
4317 excess_data: Vec::new()
4320 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4321 // All channels should be 100 sats capacity. But for the fee experiment,
4322 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4323 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4324 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4325 // so no matter how large are other channels,
4326 // the whole path will be limited by 100 sats with just these 2 conditions:
4327 // - channel 12 capacity is 250 sats
4328 // - fee for channel 6 is 150 sats
4329 // Let's test this by enforcing these 2 conditions and removing other limits.
4330 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4331 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4332 short_channel_id: 12,
4335 cltv_expiry_delta: 0,
4336 htlc_minimum_msat: 0,
4337 htlc_maximum_msat: OptionalField::Present(250_000),
4339 fee_proportional_millionths: 0,
4340 excess_data: Vec::new()
4342 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4343 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4344 short_channel_id: 13,
4347 cltv_expiry_delta: 0,
4348 htlc_minimum_msat: 0,
4349 htlc_maximum_msat: OptionalField::Absent,
4351 fee_proportional_millionths: 0,
4352 excess_data: Vec::new()
4355 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4356 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4357 short_channel_id: 6,
4360 cltv_expiry_delta: 0,
4361 htlc_minimum_msat: 0,
4362 htlc_maximum_msat: OptionalField::Absent,
4363 fee_base_msat: 150_000,
4364 fee_proportional_millionths: 0,
4365 excess_data: Vec::new()
4367 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4368 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4369 short_channel_id: 11,
4372 cltv_expiry_delta: 0,
4373 htlc_minimum_msat: 0,
4374 htlc_maximum_msat: OptionalField::Absent,
4376 fee_proportional_millionths: 0,
4377 excess_data: Vec::new()
4381 // Attempt to route more than available results in a failure.
4382 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4383 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4384 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4385 } else { panic!(); }
4389 // Now, attempt to route 200 sats (exact amount we can route).
4390 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4391 assert_eq!(route.paths.len(), 2);
4393 let mut total_amount_paid_msat = 0;
4394 for path in &route.paths {
4395 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4396 total_amount_paid_msat += path.last().unwrap().fee_msat;
4398 assert_eq!(total_amount_paid_msat, 200_000);
4399 assert_eq!(route.get_total_fees(), 150_000);
4404 fn mpp_with_last_hops() {
4405 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4406 // via a single last-hop route hint, we'd fail to route if we first collected routes
4407 // totaling close but not quite enough to fund the full payment.
4409 // This was because we considered last-hop hints to have exactly the sought payment amount
4410 // instead of the amount we were trying to collect, needlessly limiting our path searching
4411 // at the very first hop.
4413 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4414 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4415 // to only have the remaining to-collect amount in available liquidity.
4417 // This bug appeared in production in some specific channel configurations.
4418 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4419 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4420 let scorer = test_utils::TestScorer::with_penalty(0);
4421 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4422 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4423 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4424 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4425 src_node_id: nodes[2],
4426 short_channel_id: 42,
4427 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4428 cltv_expiry_delta: 42,
4429 htlc_minimum_msat: None,
4430 htlc_maximum_msat: None,
4433 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4434 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4435 // would first use the no-fee route and then fail to find a path along the second route as
4436 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4437 // under 5% of our payment amount.
4438 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4439 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4440 short_channel_id: 1,
4443 cltv_expiry_delta: (5 << 4) | 5,
4444 htlc_minimum_msat: 0,
4445 htlc_maximum_msat: OptionalField::Present(99_000),
4446 fee_base_msat: u32::max_value(),
4447 fee_proportional_millionths: u32::max_value(),
4448 excess_data: Vec::new()
4450 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4451 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4452 short_channel_id: 2,
4455 cltv_expiry_delta: (5 << 4) | 3,
4456 htlc_minimum_msat: 0,
4457 htlc_maximum_msat: OptionalField::Present(99_000),
4458 fee_base_msat: u32::max_value(),
4459 fee_proportional_millionths: u32::max_value(),
4460 excess_data: Vec::new()
4462 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4464 short_channel_id: 4,
4467 cltv_expiry_delta: (4 << 4) | 1,
4468 htlc_minimum_msat: 0,
4469 htlc_maximum_msat: OptionalField::Absent,
4471 fee_proportional_millionths: 0,
4472 excess_data: Vec::new()
4474 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4475 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4476 short_channel_id: 13,
4478 flags: 0|2, // Channel disabled
4479 cltv_expiry_delta: (13 << 4) | 1,
4480 htlc_minimum_msat: 0,
4481 htlc_maximum_msat: OptionalField::Absent,
4483 fee_proportional_millionths: 2000000,
4484 excess_data: Vec::new()
4487 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4489 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4490 assert_eq!(route.paths.len(), 2);
4491 // Paths are somewhat randomly ordered, but:
4492 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4493 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4494 assert_eq!(route.paths[0][0].short_channel_id, 2);
4495 assert_eq!(route.paths[0][0].fee_msat, 1);
4496 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4497 assert_eq!(route.paths[1][0].short_channel_id, 1);
4498 assert_eq!(route.paths[1][0].fee_msat, 0);
4499 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4500 assert_eq!(route.get_total_fees(), 1);
4501 assert_eq!(route.get_total_amount(), 100_000);
4505 fn drop_lowest_channel_mpp_route_test() {
4506 // This test checks that low-capacity channel is dropped when after
4507 // path finding we realize that we found more capacity than we need.
4508 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4509 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4510 let scorer = test_utils::TestScorer::with_penalty(0);
4511 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4512 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4513 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4515 // We need a route consisting of 3 paths:
4516 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4518 // The first and the second paths should be sufficient, but the third should be
4519 // cheaper, so that we select it but drop later.
4521 // First, we set limits on these (previously unlimited) channels.
4522 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4524 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4525 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4526 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4527 short_channel_id: 1,
4530 cltv_expiry_delta: 0,
4531 htlc_minimum_msat: 0,
4532 htlc_maximum_msat: OptionalField::Present(100_000),
4534 fee_proportional_millionths: 0,
4535 excess_data: Vec::new()
4537 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4538 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4539 short_channel_id: 3,
4542 cltv_expiry_delta: 0,
4543 htlc_minimum_msat: 0,
4544 htlc_maximum_msat: OptionalField::Present(50_000),
4546 fee_proportional_millionths: 0,
4547 excess_data: Vec::new()
4550 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4551 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4552 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4553 short_channel_id: 12,
4556 cltv_expiry_delta: 0,
4557 htlc_minimum_msat: 0,
4558 htlc_maximum_msat: OptionalField::Present(60_000),
4560 fee_proportional_millionths: 0,
4561 excess_data: Vec::new()
4563 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4564 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4565 short_channel_id: 13,
4568 cltv_expiry_delta: 0,
4569 htlc_minimum_msat: 0,
4570 htlc_maximum_msat: OptionalField::Present(60_000),
4572 fee_proportional_millionths: 0,
4573 excess_data: Vec::new()
4576 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4577 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4578 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4579 short_channel_id: 2,
4582 cltv_expiry_delta: 0,
4583 htlc_minimum_msat: 0,
4584 htlc_maximum_msat: OptionalField::Present(20_000),
4586 fee_proportional_millionths: 0,
4587 excess_data: Vec::new()
4589 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4590 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4591 short_channel_id: 4,
4594 cltv_expiry_delta: 0,
4595 htlc_minimum_msat: 0,
4596 htlc_maximum_msat: OptionalField::Present(20_000),
4598 fee_proportional_millionths: 0,
4599 excess_data: Vec::new()
4603 // Attempt to route more than available results in a failure.
4604 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4605 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4606 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4607 } else { panic!(); }
4611 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4612 // Our algorithm should provide us with these 3 paths.
4613 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4614 assert_eq!(route.paths.len(), 3);
4615 let mut total_amount_paid_msat = 0;
4616 for path in &route.paths {
4617 assert_eq!(path.len(), 2);
4618 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4619 total_amount_paid_msat += path.last().unwrap().fee_msat;
4621 assert_eq!(total_amount_paid_msat, 125_000);
4625 // Attempt to route without the last small cheap channel
4626 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4627 assert_eq!(route.paths.len(), 2);
4628 let mut total_amount_paid_msat = 0;
4629 for path in &route.paths {
4630 assert_eq!(path.len(), 2);
4631 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4632 total_amount_paid_msat += path.last().unwrap().fee_msat;
4634 assert_eq!(total_amount_paid_msat, 90_000);
4639 fn min_criteria_consistency() {
4640 // Test that we don't use an inconsistent metric between updating and walking nodes during
4641 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4642 // was updated with a different criterion from the heap sorting, resulting in loops in
4643 // calculated paths. We test for that specific case here.
4645 // We construct a network that looks like this:
4647 // node2 -1(3)2- node3
4651 // node1 -1(5)2- node4 -1(1)2- node6
4657 // We create a loop on the side of our real path - our destination is node 6, with a
4658 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4659 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4660 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4661 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4662 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4663 // "previous hop" being set to node 3, creating a loop in the path.
4664 let secp_ctx = Secp256k1::new();
4665 let logger = Arc::new(test_utils::TestLogger::new());
4666 let network = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
4667 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network), None, Arc::clone(&logger));
4668 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4669 let scorer = test_utils::TestScorer::with_penalty(0);
4670 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4671 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4672 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4674 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4675 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4676 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4677 short_channel_id: 6,
4680 cltv_expiry_delta: (6 << 4) | 0,
4681 htlc_minimum_msat: 0,
4682 htlc_maximum_msat: OptionalField::Absent,
4684 fee_proportional_millionths: 0,
4685 excess_data: Vec::new()
4687 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4689 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4690 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4691 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4692 short_channel_id: 5,
4695 cltv_expiry_delta: (5 << 4) | 0,
4696 htlc_minimum_msat: 0,
4697 htlc_maximum_msat: OptionalField::Absent,
4699 fee_proportional_millionths: 0,
4700 excess_data: Vec::new()
4702 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4704 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4705 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4706 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4707 short_channel_id: 4,
4710 cltv_expiry_delta: (4 << 4) | 0,
4711 htlc_minimum_msat: 0,
4712 htlc_maximum_msat: OptionalField::Absent,
4714 fee_proportional_millionths: 0,
4715 excess_data: Vec::new()
4717 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4719 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4720 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4721 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4722 short_channel_id: 3,
4725 cltv_expiry_delta: (3 << 4) | 0,
4726 htlc_minimum_msat: 0,
4727 htlc_maximum_msat: OptionalField::Absent,
4729 fee_proportional_millionths: 0,
4730 excess_data: Vec::new()
4732 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4734 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4735 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4736 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4737 short_channel_id: 2,
4740 cltv_expiry_delta: (2 << 4) | 0,
4741 htlc_minimum_msat: 0,
4742 htlc_maximum_msat: OptionalField::Absent,
4744 fee_proportional_millionths: 0,
4745 excess_data: Vec::new()
4748 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4749 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4750 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4751 short_channel_id: 1,
4754 cltv_expiry_delta: (1 << 4) | 0,
4755 htlc_minimum_msat: 100,
4756 htlc_maximum_msat: OptionalField::Absent,
4758 fee_proportional_millionths: 0,
4759 excess_data: Vec::new()
4761 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4764 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4765 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4766 assert_eq!(route.paths.len(), 1);
4767 assert_eq!(route.paths[0].len(), 3);
4769 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4770 assert_eq!(route.paths[0][0].short_channel_id, 6);
4771 assert_eq!(route.paths[0][0].fee_msat, 100);
4772 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
4773 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4774 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4776 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4777 assert_eq!(route.paths[0][1].short_channel_id, 5);
4778 assert_eq!(route.paths[0][1].fee_msat, 0);
4779 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
4780 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4781 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4783 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4784 assert_eq!(route.paths[0][2].short_channel_id, 1);
4785 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4786 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4787 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4788 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4794 fn exact_fee_liquidity_limit() {
4795 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4796 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4797 // we calculated fees on a higher value, resulting in us ignoring such paths.
4798 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4799 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4800 let scorer = test_utils::TestScorer::with_penalty(0);
4801 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4802 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4803 let payment_params = PaymentParameters::from_node_id(nodes[2]);
4805 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4807 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4808 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4809 short_channel_id: 2,
4812 cltv_expiry_delta: 0,
4813 htlc_minimum_msat: 0,
4814 htlc_maximum_msat: OptionalField::Present(85_000),
4816 fee_proportional_millionths: 0,
4817 excess_data: Vec::new()
4820 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4821 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4822 short_channel_id: 12,
4825 cltv_expiry_delta: (4 << 4) | 1,
4826 htlc_minimum_msat: 0,
4827 htlc_maximum_msat: OptionalField::Present(270_000),
4829 fee_proportional_millionths: 1000000,
4830 excess_data: Vec::new()
4834 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4835 // 200% fee charged channel 13 in the 1-to-2 direction.
4836 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4837 assert_eq!(route.paths.len(), 1);
4838 assert_eq!(route.paths[0].len(), 2);
4840 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4841 assert_eq!(route.paths[0][0].short_channel_id, 12);
4842 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4843 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4844 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4845 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4847 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4848 assert_eq!(route.paths[0][1].short_channel_id, 13);
4849 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4850 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4851 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4852 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4857 fn htlc_max_reduction_below_min() {
4858 // Test that if, while walking the graph, we reduce the value being sent to meet an
4859 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4860 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4861 // resulting in us thinking there is no possible path, even if other paths exist.
4862 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4863 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4864 let scorer = test_utils::TestScorer::with_penalty(0);
4865 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4866 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4867 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4869 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4870 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4871 // then try to send 90_000.
4872 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4873 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4874 short_channel_id: 2,
4877 cltv_expiry_delta: 0,
4878 htlc_minimum_msat: 0,
4879 htlc_maximum_msat: OptionalField::Present(80_000),
4881 fee_proportional_millionths: 0,
4882 excess_data: Vec::new()
4884 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4885 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4886 short_channel_id: 4,
4889 cltv_expiry_delta: (4 << 4) | 1,
4890 htlc_minimum_msat: 90_000,
4891 htlc_maximum_msat: OptionalField::Absent,
4893 fee_proportional_millionths: 0,
4894 excess_data: Vec::new()
4898 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
4899 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
4900 // expensive) channels 12-13 path.
4901 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4902 assert_eq!(route.paths.len(), 1);
4903 assert_eq!(route.paths[0].len(), 2);
4905 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4906 assert_eq!(route.paths[0][0].short_channel_id, 12);
4907 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4908 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4909 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4910 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4912 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4913 assert_eq!(route.paths[0][1].short_channel_id, 13);
4914 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4915 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4916 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
4917 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4922 fn multiple_direct_first_hops() {
4923 // Previously we'd only ever considered one first hop path per counterparty.
4924 // However, as we don't restrict users to one channel per peer, we really need to support
4925 // looking at all first hop paths.
4926 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
4927 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
4928 // route over multiple channels with the same first hop.
4929 let secp_ctx = Secp256k1::new();
4930 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4931 let logger = Arc::new(test_utils::TestLogger::new());
4932 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
4933 let scorer = test_utils::TestScorer::with_penalty(0);
4934 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
4935 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4936 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4939 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4940 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
4941 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
4942 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4943 assert_eq!(route.paths.len(), 1);
4944 assert_eq!(route.paths[0].len(), 1);
4946 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4947 assert_eq!(route.paths[0][0].short_channel_id, 3);
4948 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4951 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4952 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4953 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4954 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4955 assert_eq!(route.paths.len(), 2);
4956 assert_eq!(route.paths[0].len(), 1);
4957 assert_eq!(route.paths[1].len(), 1);
4959 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4960 assert_eq!(route.paths[0][0].short_channel_id, 3);
4961 assert_eq!(route.paths[0][0].fee_msat, 50_000);
4963 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
4964 assert_eq!(route.paths[1][0].short_channel_id, 2);
4965 assert_eq!(route.paths[1][0].fee_msat, 50_000);
4969 // If we have a bunch of outbound channels to the same node, where most are not
4970 // sufficient to pay the full payment, but one is, we should default to just using the
4971 // one single channel that has sufficient balance, avoiding MPP.
4973 // If we have several options above the 3xpayment value threshold, we should pick the
4974 // smallest of them, avoiding further fragmenting our available outbound balance to
4976 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4977 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4978 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4979 &get_channel_details(Some(5), nodes[0], InitFeatures::known(), 50_000),
4980 &get_channel_details(Some(6), nodes[0], InitFeatures::known(), 300_000),
4981 &get_channel_details(Some(7), nodes[0], InitFeatures::known(), 50_000),
4982 &get_channel_details(Some(8), nodes[0], InitFeatures::known(), 50_000),
4983 &get_channel_details(Some(9), nodes[0], InitFeatures::known(), 50_000),
4984 &get_channel_details(Some(4), nodes[0], InitFeatures::known(), 1_000_000),
4985 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4986 assert_eq!(route.paths.len(), 1);
4987 assert_eq!(route.paths[0].len(), 1);
4989 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4990 assert_eq!(route.paths[0][0].short_channel_id, 6);
4991 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4996 fn prefers_shorter_route_with_higher_fees() {
4997 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4998 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4999 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5001 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5002 let scorer = test_utils::TestScorer::with_penalty(0);
5003 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5004 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5005 let route = get_route(
5006 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5007 Arc::clone(&logger), &scorer, &random_seed_bytes
5009 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5011 assert_eq!(route.get_total_fees(), 100);
5012 assert_eq!(route.get_total_amount(), 100);
5013 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5015 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5016 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5017 let scorer = test_utils::TestScorer::with_penalty(100);
5018 let route = get_route(
5019 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5020 Arc::clone(&logger), &scorer, &random_seed_bytes
5022 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5024 assert_eq!(route.get_total_fees(), 300);
5025 assert_eq!(route.get_total_amount(), 100);
5026 assert_eq!(path, vec![2, 4, 7, 10]);
5029 struct BadChannelScorer {
5030 short_channel_id: u64,
5034 impl Writeable for BadChannelScorer {
5035 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5037 impl Score for BadChannelScorer {
5038 fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, _target: &NodeId) -> u64 {
5039 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5042 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5043 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5046 struct BadNodeScorer {
5051 impl Writeable for BadNodeScorer {
5052 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5055 impl Score for BadNodeScorer {
5056 fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, target: &NodeId) -> u64 {
5057 if *target == self.node_id { u64::max_value() } else { 0 }
5060 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5061 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5065 fn avoids_routing_through_bad_channels_and_nodes() {
5066 let (secp_ctx, network, _, _, logger) = build_graph();
5067 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5068 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5069 let network_graph = network.read_only();
5071 // A path to nodes[6] exists when no penalties are applied to any channel.
5072 let scorer = test_utils::TestScorer::with_penalty(0);
5073 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5074 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5075 let route = get_route(
5076 &our_id, &payment_params, &network_graph, None, 100, 42,
5077 Arc::clone(&logger), &scorer, &random_seed_bytes
5079 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5081 assert_eq!(route.get_total_fees(), 100);
5082 assert_eq!(route.get_total_amount(), 100);
5083 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5085 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5086 let scorer = BadChannelScorer { short_channel_id: 6 };
5087 let route = get_route(
5088 &our_id, &payment_params, &network_graph, None, 100, 42,
5089 Arc::clone(&logger), &scorer, &random_seed_bytes
5091 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5093 assert_eq!(route.get_total_fees(), 300);
5094 assert_eq!(route.get_total_amount(), 100);
5095 assert_eq!(path, vec![2, 4, 7, 10]);
5097 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5098 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5100 &our_id, &payment_params, &network_graph, None, 100, 42,
5101 Arc::clone(&logger), &scorer, &random_seed_bytes
5103 Err(LightningError { err, .. } ) => {
5104 assert_eq!(err, "Failed to find a path to the given destination");
5106 Ok(_) => panic!("Expected error"),
5111 fn total_fees_single_path() {
5115 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5116 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5117 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5120 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5121 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5122 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5125 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5126 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5127 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5130 payment_params: None,
5133 assert_eq!(route.get_total_fees(), 250);
5134 assert_eq!(route.get_total_amount(), 225);
5138 fn total_fees_multi_path() {
5142 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5143 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5144 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5147 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5148 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5149 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5153 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5154 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5155 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5158 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5159 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5160 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5163 payment_params: None,
5166 assert_eq!(route.get_total_fees(), 200);
5167 assert_eq!(route.get_total_amount(), 300);
5171 fn total_empty_route_no_panic() {
5172 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5173 // would both panic if the route was completely empty. We test to ensure they return 0
5174 // here, even though its somewhat nonsensical as a route.
5175 let route = Route { paths: Vec::new(), payment_params: None };
5177 assert_eq!(route.get_total_fees(), 0);
5178 assert_eq!(route.get_total_amount(), 0);
5182 fn limits_total_cltv_delta() {
5183 let (secp_ctx, network, _, _, logger) = build_graph();
5184 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5185 let network_graph = network.read_only();
5187 let scorer = test_utils::TestScorer::with_penalty(0);
5189 // Make sure that generally there is at least one route available
5190 let feasible_max_total_cltv_delta = 1008;
5191 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5192 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5193 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5194 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5195 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5196 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5197 assert_ne!(path.len(), 0);
5199 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5200 let fail_max_total_cltv_delta = 23;
5201 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5202 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5203 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5205 Err(LightningError { err, .. } ) => {
5206 assert_eq!(err, "Failed to find a path to the given destination");
5208 Ok(_) => panic!("Expected error"),
5213 fn adds_and_limits_cltv_offset() {
5214 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5215 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5217 let scorer = test_utils::TestScorer::with_penalty(0);
5219 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5220 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5221 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5222 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5223 assert_eq!(route.paths.len(), 1);
5225 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5227 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5228 let mut route_default = route.clone();
5229 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5230 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5231 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5232 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5233 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5235 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5236 let mut route_limited = route.clone();
5237 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5238 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5239 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5240 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5241 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5245 fn adds_plausible_cltv_offset() {
5246 let (secp_ctx, network, _, _, logger) = build_graph();
5247 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5248 let network_graph = network.read_only();
5249 let network_nodes = network_graph.nodes();
5250 let network_channels = network_graph.channels();
5251 let scorer = test_utils::TestScorer::with_penalty(0);
5252 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5253 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5254 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5256 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5257 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5258 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5260 let mut path_plausibility = vec![];
5262 for p in route.paths {
5263 // 1. Select random observation point
5264 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5265 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5267 prng.process_in_place(&mut random_bytes);
5268 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5269 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5271 // 2. Calculate what CLTV expiry delta we would observe there
5272 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5274 // 3. Starting from the observation point, find candidate paths
5275 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5276 candidates.push_back((observation_point, vec![]));
5278 let mut found_plausible_candidate = false;
5280 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5281 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5282 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5283 found_plausible_candidate = true;
5284 break 'candidate_loop;
5288 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5289 for channel_id in &cur_node.channels {
5290 if let Some(channel_info) = network_channels.get(&channel_id) {
5291 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5292 if let Some(channel_update_info) = dir_info.direction() {
5293 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5294 if cur_path_cltv_deltas.iter().sum::<u32>()
5295 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5296 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5297 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5298 candidates.push_back((*next_id, new_path_cltv_deltas));
5307 path_plausibility.push(found_plausible_candidate);
5309 assert!(path_plausibility.iter().all(|x| *x));
5312 #[cfg(not(feature = "no-std"))]
5313 pub(super) fn random_init_seed() -> u64 {
5314 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5315 use core::hash::{BuildHasher, Hasher};
5316 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5317 println!("Using seed of {}", seed);
5320 #[cfg(not(feature = "no-std"))]
5321 use util::ser::Readable;
5324 #[cfg(not(feature = "no-std"))]
5325 fn generate_routes() {
5326 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5328 let mut d = match super::test_utils::get_route_file() {
5335 let graph = NetworkGraph::read(&mut d).unwrap();
5336 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5337 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5339 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5340 let mut seed = random_init_seed() as usize;
5341 let nodes = graph.read_only().nodes().clone();
5342 'load_endpoints: for _ in 0..10 {
5344 seed = seed.overflowing_mul(0xdeadbeef).0;
5345 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5346 seed = seed.overflowing_mul(0xdeadbeef).0;
5347 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5348 let payment_params = PaymentParameters::from_node_id(dst);
5349 let amt = seed as u64 % 200_000_000;
5350 let params = ProbabilisticScoringParameters::default();
5351 let scorer = ProbabilisticScorer::new(params, &graph);
5352 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5353 continue 'load_endpoints;
5360 #[cfg(not(feature = "no-std"))]
5361 fn generate_routes_mpp() {
5362 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5364 let mut d = match super::test_utils::get_route_file() {
5371 let graph = NetworkGraph::read(&mut d).unwrap();
5372 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5373 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5375 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5376 let mut seed = random_init_seed() as usize;
5377 let nodes = graph.read_only().nodes().clone();
5378 'load_endpoints: for _ in 0..10 {
5380 seed = seed.overflowing_mul(0xdeadbeef).0;
5381 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5382 seed = seed.overflowing_mul(0xdeadbeef).0;
5383 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5384 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5385 let amt = seed as u64 % 200_000_000;
5386 let params = ProbabilisticScoringParameters::default();
5387 let scorer = ProbabilisticScorer::new(params, &graph);
5388 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5389 continue 'load_endpoints;
5396 #[cfg(all(test, not(feature = "no-std")))]
5397 pub(crate) mod test_utils {
5399 /// Tries to open a network graph file, or panics with a URL to fetch it.
5400 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5401 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5402 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5403 .or_else(|_| { // Fall back to guessing based on the binary location
5404 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5405 let mut path = std::env::current_exe().unwrap();
5406 path.pop(); // lightning-...
5408 path.pop(); // debug
5409 path.pop(); // target
5410 path.push("lightning");
5411 path.push("net_graph-2021-05-31.bin");
5412 eprintln!("{}", path.to_str().unwrap());
5415 .map_err(|_| "Please fetch https://bitcoin.ninja/ldk-net_graph-v0.0.15-2021-05-31.bin and place it at lightning/net_graph-2021-05-31.bin");
5416 #[cfg(require_route_graph_test)]
5417 return Ok(res.unwrap());
5418 #[cfg(not(require_route_graph_test))]
5423 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5426 use bitcoin::hashes::Hash;
5427 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5428 use chain::transaction::OutPoint;
5429 use chain::keysinterface::{KeysManager,KeysInterface};
5430 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5431 use ln::features::{InitFeatures, InvoiceFeatures};
5432 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters, Scorer};
5433 use util::logger::{Logger, Record};
5437 struct DummyLogger {}
5438 impl Logger for DummyLogger {
5439 fn log(&self, _record: &Record) {}
5442 fn read_network_graph() -> NetworkGraph {
5443 let mut d = test_utils::get_route_file().unwrap();
5444 NetworkGraph::read(&mut d).unwrap()
5447 fn payer_pubkey() -> PublicKey {
5448 let secp_ctx = Secp256k1::new();
5449 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5453 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5455 channel_id: [0; 32],
5456 counterparty: ChannelCounterparty {
5457 features: InitFeatures::known(),
5459 unspendable_punishment_reserve: 0,
5460 forwarding_info: None,
5462 funding_txo: Some(OutPoint {
5463 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5466 short_channel_id: Some(1),
5467 inbound_scid_alias: None,
5468 channel_value_satoshis: 10_000_000,
5470 balance_msat: 10_000_000,
5471 outbound_capacity_msat: 10_000_000,
5472 inbound_capacity_msat: 0,
5473 unspendable_punishment_reserve: None,
5474 confirmations_required: None,
5475 force_close_spend_delay: None,
5477 is_funding_locked: true,
5480 inbound_htlc_minimum_msat: None,
5481 inbound_htlc_maximum_msat: None,
5486 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5487 let network_graph = read_network_graph();
5488 let scorer = FixedPenaltyScorer::with_penalty(0);
5489 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5493 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5494 let network_graph = read_network_graph();
5495 let scorer = FixedPenaltyScorer::with_penalty(0);
5496 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5500 fn generate_routes_with_default_scorer(bench: &mut Bencher) {
5501 let network_graph = read_network_graph();
5502 let scorer = Scorer::default();
5503 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5507 fn generate_mpp_routes_with_default_scorer(bench: &mut Bencher) {
5508 let network_graph = read_network_graph();
5509 let scorer = Scorer::default();
5510 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5514 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5515 let network_graph = read_network_graph();
5516 let params = ProbabilisticScoringParameters::default();
5517 let scorer = ProbabilisticScorer::new(params, &network_graph);
5518 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5522 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5523 let network_graph = read_network_graph();
5524 let params = ProbabilisticScoringParameters::default();
5525 let scorer = ProbabilisticScorer::new(params, &network_graph);
5526 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5529 fn generate_routes<S: Score>(
5530 bench: &mut Bencher, graph: &NetworkGraph, mut scorer: S, features: InvoiceFeatures
5532 let nodes = graph.read_only().nodes().clone();
5533 let payer = payer_pubkey();
5534 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5535 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5537 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5538 let mut routes = Vec::new();
5539 let mut route_endpoints = Vec::new();
5540 let mut seed: usize = 0xdeadbeef;
5541 'load_endpoints: for _ in 0..150 {
5544 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5546 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5547 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5548 let first_hop = first_hop(src);
5549 let amt = seed as u64 % 1_000_000;
5550 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5552 route_endpoints.push((first_hop, params, amt));
5553 continue 'load_endpoints;
5558 // ...and seed the scorer with success and failure data...
5559 for route in routes {
5560 let amount = route.get_total_amount();
5561 if amount < 250_000 {
5562 for path in route.paths {
5563 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5565 } else if amount > 750_000 {
5566 for path in route.paths {
5567 let short_channel_id = path[path.len() / 2].short_channel_id;
5568 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5573 // Because we've changed channel scores, its possible we'll take different routes to the
5574 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5575 // requires a too-high CLTV delta.
5576 route_endpoints.retain(|(first_hop, params, amt)| {
5577 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5579 route_endpoints.truncate(100);
5580 assert_eq!(route_endpoints.len(), 100);
5582 // ...then benchmark finding paths between the nodes we learned.
5585 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5586 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());