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::{ChannelUseParameters, Score};
21 use routing::network_graph::{DirectedChannelInfo, EffectiveCapacity, NetworkGraph, NodeId, RoutingFees};
22 use util::ser::{Writeable, Readable};
23 use util::logger::{Level, Logger};
27 use alloc::collections::BinaryHeap;
32 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
34 /// The node_id of the node at this hop.
35 pub pubkey: PublicKey,
36 /// The node_announcement features of the node at this hop. For the last hop, these may be
37 /// amended to match the features present in the invoice this node generated.
38 pub node_features: NodeFeatures,
39 /// The channel that should be used from the previous hop to reach this node.
40 pub short_channel_id: u64,
41 /// The channel_announcement features of the channel that should be used from the previous hop
42 /// to reach this node.
43 pub channel_features: ChannelFeatures,
44 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
45 /// For the last hop, this should be the full value of the payment (might be more than
46 /// requested if we had to match htlc_minimum_msat).
48 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
49 /// expected at the destination, in excess of the current block height.
50 pub cltv_expiry_delta: u32,
53 impl_writeable_tlv_based!(RouteHop, {
54 (0, pubkey, required),
55 (2, node_features, required),
56 (4, short_channel_id, required),
57 (6, channel_features, required),
58 (8, fee_msat, required),
59 (10, cltv_expiry_delta, required),
62 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
63 /// it can take multiple paths. Each path is composed of one or more hops through the network.
64 #[derive(Clone, Hash, PartialEq, Eq)]
66 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
67 /// last RouteHop in each path must be the same.
68 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
69 /// destination. Thus, this must always be at least length one. While the maximum length of any
70 /// given path is variable, keeping the length of any path to less than 20 should currently
71 /// ensure it is viable.
72 pub paths: Vec<Vec<RouteHop>>,
73 /// The `payee` parameter passed to [`find_route`].
74 /// This is used by `ChannelManager` to track information which may be required for retries,
75 /// provided back to you via [`Event::PaymentPathFailed`].
77 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
78 pub payee: Option<Payee>,
81 pub(crate) trait RoutePath {
82 /// Gets the fees for a given path, excluding any excess paid to the recipient.
83 fn get_path_fees(&self) -> u64;
85 impl RoutePath for Vec<RouteHop> {
86 fn get_path_fees(&self) -> u64 {
87 // Do not count last hop of each path since that's the full value of the payment
88 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
89 .iter().map(|hop| &hop.fee_msat)
95 /// Returns the total amount of fees paid on this [`Route`].
97 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
98 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
99 pub fn get_total_fees(&self) -> u64 {
100 self.paths.iter().map(|path| path.get_path_fees()).sum()
103 /// Returns the total amount paid on this [`Route`], excluding the fees.
104 pub fn get_total_amount(&self) -> u64 {
105 return self.paths.iter()
106 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
111 const SERIALIZATION_VERSION: u8 = 1;
112 const MIN_SERIALIZATION_VERSION: u8 = 1;
114 impl Writeable for Route {
115 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
116 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
117 (self.paths.len() as u64).write(writer)?;
118 for hops in self.paths.iter() {
119 (hops.len() as u8).write(writer)?;
120 for hop in hops.iter() {
124 write_tlv_fields!(writer, {
125 (1, self.payee, option),
131 impl Readable for Route {
132 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
133 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
134 let path_count: u64 = Readable::read(reader)?;
135 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
136 for _ in 0..path_count {
137 let hop_count: u8 = Readable::read(reader)?;
138 let mut hops = Vec::with_capacity(hop_count as usize);
139 for _ in 0..hop_count {
140 hops.push(Readable::read(reader)?);
144 let mut payee = None;
145 read_tlv_fields!(reader, {
148 Ok(Route { paths, payee })
152 /// Parameters needed to find a [`Route`] for paying a [`Payee`].
154 /// Passed to [`find_route`] and also provided in [`Event::PaymentPathFailed`] for retrying a failed
157 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
158 #[derive(Clone, Debug)]
159 pub struct RouteParameters {
160 /// The recipient of the failed payment path.
163 /// The amount in msats sent on the failed payment path.
164 pub final_value_msat: u64,
166 /// The CLTV on the final hop of the failed payment path.
167 pub final_cltv_expiry_delta: u32,
170 impl_writeable_tlv_based!(RouteParameters, {
171 (0, payee, required),
172 (2, final_value_msat, required),
173 (4, final_cltv_expiry_delta, required),
176 /// Maximum total CTLV difference we allow for a full payment path.
177 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
179 /// The recipient of a payment.
180 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
182 /// The node id of the payee.
183 pub pubkey: PublicKey,
185 /// Features supported by the payee.
187 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
188 /// does not contain any features.
190 /// [`for_keysend`]: Self::for_keysend
191 pub features: Option<InvoiceFeatures>,
193 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
194 pub route_hints: Vec<RouteHint>,
196 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
197 pub expiry_time: Option<u64>,
199 /// The maximum total CLTV delta we accept for the route.
200 pub max_total_cltv_expiry_delta: u32,
203 impl_writeable_tlv_based!(Payee, {
204 (0, pubkey, required),
205 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
206 (2, features, option),
207 (4, route_hints, vec_type),
208 (6, expiry_time, option),
212 /// Creates a payee with the node id of the given `pubkey`.
213 pub fn from_node_id(pubkey: PublicKey) -> Self {
219 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
223 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
224 pub fn for_keysend(pubkey: PublicKey) -> Self {
225 Self::from_node_id(pubkey).with_features(InvoiceFeatures::for_keysend())
228 /// Includes the payee's features.
230 /// (C-not exported) since bindings don't support move semantics
231 pub fn with_features(self, features: InvoiceFeatures) -> Self {
232 Self { features: Some(features), ..self }
235 /// Includes hints for routing to the payee.
237 /// (C-not exported) since bindings don't support move semantics
238 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
239 Self { route_hints, ..self }
242 /// Includes a payment expiration in seconds relative to the UNIX epoch.
244 /// (C-not exported) since bindings don't support move semantics
245 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
246 Self { expiry_time: Some(expiry_time), ..self }
249 /// Includes a limit for the total CLTV expiry delta which is considered during routing
251 /// (C-not exported) since bindings don't support move semantics
252 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
253 Self { max_total_cltv_expiry_delta, ..self }
257 /// A list of hops along a payment path terminating with a channel to the recipient.
258 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
259 pub struct RouteHint(pub Vec<RouteHintHop>);
262 impl Writeable for RouteHint {
263 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
264 (self.0.len() as u64).write(writer)?;
265 for hop in self.0.iter() {
272 impl Readable for RouteHint {
273 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
274 let hop_count: u64 = Readable::read(reader)?;
275 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
276 for _ in 0..hop_count {
277 hops.push(Readable::read(reader)?);
283 /// A channel descriptor for a hop along a payment path.
284 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
285 pub struct RouteHintHop {
286 /// The node_id of the non-target end of the route
287 pub src_node_id: PublicKey,
288 /// The short_channel_id of this channel
289 pub short_channel_id: u64,
290 /// The fees which must be paid to use this channel
291 pub fees: RoutingFees,
292 /// The difference in CLTV values between this node and the next node.
293 pub cltv_expiry_delta: u16,
294 /// The minimum value, in msat, which must be relayed to the next hop.
295 pub htlc_minimum_msat: Option<u64>,
296 /// The maximum value in msat available for routing with a single HTLC.
297 pub htlc_maximum_msat: Option<u64>,
300 impl_writeable_tlv_based!(RouteHintHop, {
301 (0, src_node_id, required),
302 (1, htlc_minimum_msat, option),
303 (2, short_channel_id, required),
304 (3, htlc_maximum_msat, option),
306 (6, cltv_expiry_delta, required),
309 #[derive(Eq, PartialEq)]
310 struct RouteGraphNode {
312 lowest_fee_to_peer_through_node: u64,
313 lowest_fee_to_node: u64,
314 total_cltv_delta: u32,
315 // The maximum value a yet-to-be-constructed payment path might flow through this node.
316 // This value is upper-bounded by us by:
317 // - how much is needed for a path being constructed
318 // - how much value can channels following this node (up to the destination) can contribute,
319 // considering their capacity and fees
320 value_contribution_msat: u64,
321 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
322 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
323 path_htlc_minimum_msat: u64,
324 /// All costs incurred from this hop on the way to the destination, as calculated using channel
329 impl cmp::Ord for RouteGraphNode {
330 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
331 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat)
332 .checked_add(other.path_cost)
333 .unwrap_or_else(|| u64::max_value());
334 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat)
335 .checked_add(self.path_cost)
336 .unwrap_or_else(|| u64::max_value());
337 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
341 impl cmp::PartialOrd for RouteGraphNode {
342 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
343 Some(self.cmp(other))
347 /// A wrapper around the various hop representations.
349 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
350 #[derive(Clone, Debug)]
351 enum CandidateRouteHop<'a> {
352 /// A hop from the payer to the next hop to the payee, where the outbound liquidity is known.
354 details: &'a ChannelDetails,
356 /// A hop found in the [`NetworkGraph`], where the channel capacity may or may not be known.
358 // `DirectedChannelInfo::direction` MUST NOT be `None`.
359 info: DirectedChannelInfo<'a, '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 fn features(&self) -> ChannelFeatures {
379 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
380 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
381 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
385 fn cltv_expiry_delta(&self) -> u32 {
387 CandidateRouteHop::FirstHop { .. } => 0,
388 CandidateRouteHop::PublicHop { info, .. } => {
389 info.direction().unwrap().cltv_expiry_delta as u32
391 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
395 fn htlc_minimum_msat(&self) -> u64 {
397 CandidateRouteHop::FirstHop { .. } => 0,
398 CandidateRouteHop::PublicHop { info, .. } => {
399 info.direction().unwrap().htlc_minimum_msat
401 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
405 fn htlc_maximum_msat(&self) -> u64 {
407 CandidateRouteHop::FirstHop { details } => details.outbound_capacity_msat,
408 CandidateRouteHop::PublicHop { info, .. } => info.htlc_maximum_msat(),
409 CandidateRouteHop::PrivateHop { hint } => {
410 hint.htlc_maximum_msat.unwrap_or(u64::max_value())
415 fn fees(&self) -> RoutingFees {
417 CandidateRouteHop::FirstHop { .. } => RoutingFees {
418 base_msat: 0, proportional_millionths: 0,
420 CandidateRouteHop::PublicHop { info, .. } => info.direction().unwrap().fees,
421 CandidateRouteHop::PrivateHop { hint } => hint.fees,
425 fn effective_capacity(&self) -> EffectiveCapacity {
427 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
428 liquidity_msat: details.outbound_capacity_msat,
430 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
431 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
435 fn available_liquidity(&self) -> AvailableLiquidity {
437 htlc_maximum_msat: self.htlc_maximum_msat(),
438 remaining_capacity_msat: self.effective_capacity().as_msat(),
443 /// The liquidity available in a channel when making routing decisions for a payment.
445 /// Used by `find_route` to determine if an HTLC can be routed through the channel. This is bounded
446 /// by the channel's `htlc_maximum_msat`, if known, or the channel's capacity, if known, whichever
447 /// is smaller. Use of the channel may reduce the available liquidity for subsequent MPP paths
448 /// within the same payment.
450 /// This information is ephemeral in that it does not carry across calls to `find_route`. Rather it
451 /// is used simply to inform whether a channel can be used in multiple paths.
452 struct AvailableLiquidity {
453 htlc_maximum_msat: u64,
454 remaining_capacity_msat: u64,
457 impl AvailableLiquidity {
458 fn as_msat(&self) -> u64 {
459 core::cmp::min(self.htlc_maximum_msat, self.remaining_capacity_msat)
462 fn reduce_by(&mut self, amount_msat: u64) -> &mut Self {
463 self.remaining_capacity_msat -= amount_msat;
467 fn exhaust(&mut self) {
468 self.remaining_capacity_msat = 0;
472 /// It's useful to keep track of the hops associated with the fees required to use them,
473 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
474 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
475 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
476 #[derive(Clone, Debug)]
477 struct PathBuildingHop<'a> {
478 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
479 // is a larger refactor and will require careful performance analysis.
481 candidate: CandidateRouteHop<'a>,
484 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
485 src_lowest_inbound_fees: RoutingFees,
486 /// All the fees paid *after* this channel on the way to the destination
487 next_hops_fee_msat: u64,
488 /// Fee paid for the use of the current channel (see candidate.fees()).
489 /// The value will be actually deducted from the counterparty balance on the previous link.
490 hop_use_fee_msat: u64,
491 /// Used to compare channels when choosing the for routing.
492 /// Includes paying for the use of a hop and the following hops, as well as
493 /// an estimated cost of reaching this hop.
494 /// Might get stale when fees are recomputed. Primarily for internal use.
496 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
497 /// walk and may be invalid thereafter.
498 path_htlc_minimum_msat: u64,
499 /// All costs incurred from this channel on the way to the destination, as calculated using
502 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
503 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
504 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
505 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
506 /// avoid processing them again.
508 #[cfg(any(test, feature = "fuzztarget"))]
509 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
510 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
511 // value_contribution_msat, which requires tracking it here. See comments below where it is
512 // used for more info.
513 value_contribution_msat: u64,
516 // Instantiated with a list of hops with correct data in them collected during path finding,
517 // an instance of this struct should be further modified only via given methods.
519 struct PaymentPath<'a> {
520 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
523 impl<'a> PaymentPath<'a> {
524 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
525 fn get_value_msat(&self) -> u64 {
526 self.hops.last().unwrap().0.fee_msat
529 fn get_total_fee_paid_msat(&self) -> u64 {
530 if self.hops.len() < 1 {
534 // Can't use next_hops_fee_msat because it gets outdated.
535 for (i, (hop, _)) in self.hops.iter().enumerate() {
536 if i != self.hops.len() - 1 {
537 result += hop.fee_msat;
543 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
544 // to change fees may result in an inconsistency.
546 // Sometimes we call this function right after constructing a path which is inconsistent in
547 // that it the value being transferred has decreased while we were doing path finding, leading
548 // to the fees being paid not lining up with the actual limits.
550 // Note that this function is not aware of the available_liquidity limit, and thus does not
551 // support increasing the value being transferred.
552 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
553 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
555 let mut total_fee_paid_msat = 0 as u64;
556 for i in (0..self.hops.len()).rev() {
557 let last_hop = i == self.hops.len() - 1;
559 // For non-last-hop, this value will represent the fees paid on the current hop. It
560 // will consist of the fees for the use of the next hop, and extra fees to match
561 // htlc_minimum_msat of the current channel. Last hop is handled separately.
562 let mut cur_hop_fees_msat = 0;
564 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
567 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
568 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
569 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
570 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
571 // set it too high just to maliciously take more fees by exploiting this
572 // match htlc_minimum_msat logic.
573 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
574 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
575 // Note that there is a risk that *previous hops* (those closer to us, as we go
576 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
578 // This might make us end up with a broken route, although this should be super-rare
579 // in practice, both because of how healthy channels look like, and how we pick
580 // channels in add_entry.
581 // Also, this can't be exploited more heavily than *announce a free path and fail
583 cur_hop_transferred_amount_msat += extra_fees_msat;
584 total_fee_paid_msat += extra_fees_msat;
585 cur_hop_fees_msat += extra_fees_msat;
589 // Final hop is a special case: it usually has just value_msat (by design), but also
590 // it still could overpay for the htlc_minimum_msat.
591 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
593 // Propagate updated fees for the use of the channels to one hop back, where they
594 // will be actually paid (fee_msat). The last hop is handled above separately.
595 cur_hop.fee_msat = cur_hop_fees_msat;
598 // Fee for the use of the current hop which will be deducted on the previous hop.
599 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
600 // this channel is free for us.
602 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
603 cur_hop.hop_use_fee_msat = new_fee;
604 total_fee_paid_msat += new_fee;
606 // It should not be possible because this function is called only to reduce the
607 // value. In that case, compute_fee was already called with the same fees for
608 // larger amount and there was no overflow.
616 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
617 let proportional_fee_millions =
618 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
619 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
620 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
624 // This function may be (indirectly) called without any verification,
625 // with channel_fees provided by a caller. We should handle it gracefully.
630 /// Finds a route from us (payer) to the given target node (payee).
632 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
633 /// Without this, MPP will only be used if the payee's features are available in the network graph.
635 /// Private routing paths between a public node and the target may be included in `params.payee`.
637 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
638 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of our local
639 /// channels from [`NetworkGraph`] will be ignored, and only those in `first_hops` will be used.
641 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
642 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
643 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
647 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
648 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
653 /// Panics if first_hops contains channels without short_channel_ids;
654 /// [`ChannelManager::list_usable_channels`] will never include such channels.
656 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
657 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
658 pub fn find_route<L: Deref, S: Score>(
659 our_node_pubkey: &PublicKey, params: &RouteParameters, network: &NetworkGraph,
660 first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S
661 ) -> Result<Route, LightningError>
662 where L::Target: Logger {
664 our_node_pubkey, ¶ms.payee, network, first_hops, params.final_value_msat,
665 params.final_cltv_expiry_delta, logger, scorer
669 pub(crate) fn get_route<L: Deref, S: Score>(
670 our_node_pubkey: &PublicKey, payee: &Payee, network: &NetworkGraph,
671 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
672 logger: L, scorer: &S
673 ) -> Result<Route, LightningError>
674 where L::Target: Logger {
675 let payee_node_id = NodeId::from_pubkey(&payee.pubkey);
676 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
678 if payee_node_id == our_node_id {
679 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
682 if final_value_msat > MAX_VALUE_MSAT {
683 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
686 if final_value_msat == 0 {
687 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
690 for route in payee.route_hints.iter() {
691 for hop in &route.0 {
692 if hop.src_node_id == payee.pubkey {
693 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
698 // The general routing idea is the following:
699 // 1. Fill first/last hops communicated by the caller.
700 // 2. Attempt to construct a path from payer to payee for transferring
701 // any ~sufficient (described later) value.
702 // If succeed, remember which channels were used and how much liquidity they have available,
703 // so that future paths don't rely on the same liquidity.
704 // 3. Proceed to the next step if:
705 // - we hit the recommended target value;
706 // - OR if we could not construct a new path. Any next attempt will fail too.
707 // Otherwise, repeat step 2.
708 // 4. See if we managed to collect paths which aggregately are able to transfer target value
709 // (not recommended value). If yes, proceed. If not, fail routing.
710 // 5. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
711 // 6. Of all the found paths, select only those with the lowest total fee.
712 // 7. The last path in every selected route is likely to be more than we need.
713 // Reduce its value-to-transfer and recompute fees.
714 // 8. Choose the best route by the lowest total fee.
716 // As for the actual search algorithm,
717 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
718 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
720 // We are not a faithful Dijkstra's implementation because we can change values which impact
721 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
722 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
723 // the value we are currently attempting to send over a path, we simply reduce the value being
724 // sent along the path for any hops after that channel. This may imply that later fees (which
725 // we've already tabulated) are lower because a smaller value is passing through the channels
726 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
727 // channels which were selected earlier (and which may still be used for other paths without a
728 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
731 // One potentially problematic case for this algorithm would be if there are many
732 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
733 // graph walking), we may never find a path which is not liquidity-limited and has lower
734 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
735 // Because we only consider paths with at least 5% of the total value being sent, the damage
736 // from such a case should be limited, however this could be further reduced in the future by
737 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
738 // limits for the purposes of fee calculation.
740 // Alternatively, we could store more detailed path information in the heap (targets, below)
741 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
742 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
743 // and practically (as we would need to store dynamically-allocated path information in heap
744 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
745 // results of such an algorithm would likely be biased towards lower-value paths.
747 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
748 // outside of our current search value, running a path search more times to gather candidate
749 // paths at different values. While this may be acceptable, further path searches may increase
750 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
751 // graph for candidate paths, calculating the maximum value which can realistically be sent at
752 // the same time, remaining generic across different payment values.
754 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
755 // to use as the A* heuristic beyond just the cost to get one node further than the current
758 let network_graph = network.read_only();
759 let network_channels = network_graph.channels();
760 let network_nodes = network_graph.nodes();
762 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
763 // it. If the payee supports it they're supposed to include it in the invoice, so that should
765 let allow_mpp = if let Some(features) = &payee.features {
766 features.supports_basic_mpp()
767 } else if let Some(node) = network_nodes.get(&payee_node_id) {
768 if let Some(node_info) = node.announcement_info.as_ref() {
769 node_info.features.supports_basic_mpp()
772 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP", our_node_pubkey,
773 payee.pubkey, if allow_mpp { "with" } else { "without" });
776 // Prepare the data we'll use for payee-to-payer search by
777 // inserting first hops suggested by the caller as targets.
778 // Our search will then attempt to reach them while traversing from the payee node.
779 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
780 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
781 if let Some(hops) = first_hops {
783 if chan.short_channel_id.is_none() {
784 panic!("first_hops should be filled in with usable channels, not pending ones");
786 if chan.counterparty.node_id == *our_node_pubkey {
787 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
790 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
791 .or_insert(Vec::new())
794 if first_hop_targets.is_empty() {
795 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
799 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
800 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
801 // adding duplicate entries when we find a better path to a given node.
802 let mut targets = BinaryHeap::new();
804 // Map from node_id to information about the best current path to that node, including feerate
806 let mut dist = HashMap::with_capacity(network_nodes.len());
808 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
809 // indicating that we may wish to try again with a higher value, potentially paying to meet an
810 // htlc_minimum with extra fees while still finding a cheaper path.
811 let mut hit_minimum_limit;
813 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
814 // We start with a path_value of the exact amount we want, and if that generates a route we may
815 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
816 // amount we want in total across paths, selecting the best subset at the end.
817 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
818 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
819 let mut path_value_msat = final_value_msat;
821 // Keep track of how much liquidity is still available in selected channels. Used to determine
822 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
823 // unaware of the direction.
824 let mut available_channel_liquidities = HashMap::with_capacity(network_nodes.len());
826 // Keeping track of how much value we already collected across other paths. Helps to decide:
827 // - how much a new path should be transferring (upper bound);
828 // - whether a channel should be disregarded because
829 // it's available liquidity is too small comparing to how much more we need to collect;
830 // - when we want to stop looking for new paths.
831 let mut already_collected_value_msat = 0;
833 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payee.pubkey, our_node_pubkey, final_value_msat);
835 macro_rules! add_entry {
836 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
837 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
838 // since that value has to be transferred over this channel.
839 // Returns whether this channel caused an update to `targets`.
840 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
841 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
842 $next_hops_path_cost: expr, $next_hops_cltv_delta: expr ) => { {
843 // We "return" whether we updated the path at the end, via this:
844 let mut did_add_update_path_to_src_node = false;
845 // Channels to self should not be used. This is more of belt-and-suspenders, because in
846 // practice these cases should be caught earlier:
847 // - for regular channels at channel announcement (TODO)
848 // - for first and last hops early in get_route
849 if $src_node_id != $dest_node_id {
850 let short_channel_id = $candidate.short_channel_id();
851 let available_liquidity = available_channel_liquidities
852 .entry((short_channel_id, $src_node_id < $dest_node_id))
853 .or_insert_with(|| $candidate.available_liquidity());
854 let available_liquidity_msat = available_liquidity.as_msat();
856 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
857 // It may be misleading because we might later choose to reduce the value transferred
858 // over these channels, and the channel which was insufficient might become sufficient.
859 // Worst case: we drop a good channel here because it can't cover the high following
860 // fees caused by one expensive channel, but then this channel could have been used
861 // if the amount being transferred over this path is lower.
862 // We do this for now, but this is a subject for removal.
863 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
865 // Routing Fragmentation Mitigation heuristic:
867 // Routing fragmentation across many payment paths increases the overall routing
868 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
869 // Taking too many smaller paths also increases the chance of payment failure.
870 // Thus to avoid this effect, we require from our collected links to provide
871 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
873 // This requirement is currently 5% of the remaining-to-be-collected value.
874 // This means as we successfully advance in our collection,
875 // the absolute liquidity contribution is lowered,
876 // thus increasing the number of potential channels to be selected.
878 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
879 // or 100% if we're not allowed to do multipath payments.
880 let minimal_value_contribution_msat: u64 = if allow_mpp {
881 (recommended_value_msat - already_collected_value_msat + 19) / 20
885 // Verify the liquidity offered by this channel complies to the minimal contribution.
886 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
888 // Do not consider candidates that exceed the maximum total cltv expiry limit.
889 let max_total_cltv_expiry_delta = payee.max_total_cltv_expiry_delta;
890 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
891 .checked_add($candidate.cltv_expiry_delta())
892 .unwrap_or(u32::max_value());
893 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
895 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
896 // Includes paying fees for the use of the following channels.
897 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
898 Some(result) => result,
899 // Can't overflow due to how the values were computed right above.
900 None => unreachable!(),
902 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
903 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
904 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
906 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
907 // bother considering this channel.
908 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
909 // be only reduced later (not increased), so this channel should just be skipped
910 // as not sufficient.
911 if !over_path_minimum_msat && doesnt_exceed_cltv_delta_limit {
912 hit_minimum_limit = true;
913 } else if contributes_sufficient_value && doesnt_exceed_cltv_delta_limit {
914 // Note that low contribution here (limited by available_liquidity_msat)
915 // might violate htlc_minimum_msat on the hops which are next along the
916 // payment path (upstream to the payee). To avoid that, we recompute
917 // path fees knowing the final path contribution after constructing it.
918 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
919 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
920 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
921 .unwrap_or_else(|| u64::max_value());
922 let hm_entry = dist.entry($src_node_id);
923 let old_entry = hm_entry.or_insert_with(|| {
924 // If there was previously no known way to access the source node
925 // (recall it goes payee-to-payer) of short_channel_id, first add a
926 // semi-dummy record just to compute the fees to reach the source node.
927 // This will affect our decision on selecting short_channel_id
928 // as a way to reach the $dest_node_id.
929 let mut fee_base_msat = u32::max_value();
930 let mut fee_proportional_millionths = u32::max_value();
931 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
932 fee_base_msat = fees.base_msat;
933 fee_proportional_millionths = fees.proportional_millionths;
936 node_id: $dest_node_id.clone(),
937 candidate: $candidate.clone(),
939 src_lowest_inbound_fees: RoutingFees {
940 base_msat: fee_base_msat,
941 proportional_millionths: fee_proportional_millionths,
943 next_hops_fee_msat: u64::max_value(),
944 hop_use_fee_msat: u64::max_value(),
945 total_fee_msat: u64::max_value(),
946 path_htlc_minimum_msat,
947 path_cost: u64::max_value(),
948 was_processed: false,
949 #[cfg(any(test, feature = "fuzztarget"))]
950 value_contribution_msat,
954 #[allow(unused_mut)] // We only use the mut in cfg(test)
955 let mut should_process = !old_entry.was_processed;
956 #[cfg(any(test, feature = "fuzztarget"))]
958 // In test/fuzzing builds, we do extra checks to make sure the skipping
959 // of already-seen nodes only happens in cases we expect (see below).
960 if !should_process { should_process = true; }
964 let mut hop_use_fee_msat = 0;
965 let mut total_fee_msat = $next_hops_fee_msat;
967 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
968 // will have the same effective-fee
969 if $src_node_id != our_node_id {
970 total_fee_msat = compute_fees(amount_to_transfer_over_msat, $candidate.fees())
971 .and_then(|fee_msat| {
972 hop_use_fee_msat = fee_msat;
973 total_fee_msat += hop_use_fee_msat;
974 compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
976 // When calculating the lowest inbound fees to a node, we
977 // calculate fees here not based on the actual value we think
978 // will flow over this channel, but on the minimum value that
979 // we'll accept flowing over it. The minimum accepted value
980 // is a constant through each path collection run, ensuring
981 // consistent basis. Otherwise we may later find a
982 // different path to the source node that is more expensive,
983 // but which we consider to be cheaper because we are capacity
984 // constrained and the relative fee becomes lower.
985 .and_then(|a| a.checked_add(total_fee_msat))
986 // max_value means we'll always fail
987 // the old_entry.total_fee_msat > total_fee_msat check
988 .unwrap_or_else(|| u64::max_value());
991 let effective_capacity_msat = $candidate.effective_capacity().as_msat();
992 let params = ChannelUseParameters {
993 amount_msat: amount_to_transfer_over_msat,
994 inflight_htlc_msat: effective_capacity_msat - available_liquidity.remaining_capacity_msat,
995 fees_msat: cmp::max(total_fee_msat, path_htlc_minimum_msat),
996 effective_capacity_msat,
998 let channel_cost = scorer.channel_cost(short_channel_id, &$src_node_id, &$dest_node_id, params);
999 let path_cost = $next_hops_path_cost
1000 .checked_add(channel_cost)
1001 .unwrap_or_else(|| u64::max_value());
1003 let new_graph_node = RouteGraphNode {
1004 node_id: $src_node_id,
1005 lowest_fee_to_peer_through_node: total_fee_msat,
1006 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1007 total_cltv_delta: hop_total_cltv_delta,
1008 value_contribution_msat: value_contribution_msat,
1009 path_htlc_minimum_msat,
1014 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1015 // if this way is cheaper than the already known
1016 // (considering the cost to "reach" this channel from the route destination,
1017 // the cost of using this channel,
1018 // and the cost of routing to the source node of this channel).
1019 // Also, consider that htlc_minimum_msat_difference, because we might end up
1020 // paying it. Consider the following exploit:
1021 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1022 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1023 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1024 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1026 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1027 // but it may require additional tracking - we don't want to double-count
1028 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1029 // can't use something that may decrease on future hops.
1031 if !old_entry.was_processed && path_cost < old_entry.path_cost {
1032 targets.push(new_graph_node);
1033 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1034 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1035 old_entry.total_fee_msat = total_fee_msat;
1036 old_entry.node_id = $dest_node_id.clone();
1037 old_entry.candidate = $candidate.clone();
1038 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1039 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1040 old_entry.path_cost = path_cost;
1041 #[cfg(any(test, feature = "fuzztarget"))]
1043 old_entry.value_contribution_msat = value_contribution_msat;
1045 did_add_update_path_to_src_node = true;
1046 } else if old_entry.was_processed && path_cost < old_entry.path_cost {
1047 #[cfg(any(test, feature = "fuzztarget"))]
1049 // If we're skipping processing a node which was previously
1050 // processed even though we found another path to it with a
1051 // cheaper fee, check that it was because the second path we
1052 // found (which we are processing now) has a lower value
1053 // contribution due to an HTLC minimum limit.
1055 // e.g. take a graph with two paths from node 1 to node 2, one
1056 // through channel A, and one through channel B. Channel A and
1057 // B are both in the to-process heap, with their scores set by
1058 // a higher htlc_minimum than fee.
1059 // Channel A is processed first, and the channels onwards from
1060 // node 1 are added to the to-process heap. Thereafter, we pop
1061 // Channel B off of the heap, note that it has a much more
1062 // restrictive htlc_maximum_msat, and recalculate the fees for
1063 // all of node 1's channels using the new, reduced, amount.
1065 // This would be bogus - we'd be selecting a higher-fee path
1066 // with a lower htlc_maximum_msat instead of the one we'd
1067 // already decided to use.
1068 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1069 // TODO: Does this assertion still make sense?
1071 value_contribution_msat + path_cost <
1072 old_entry.value_contribution_msat + old_entry.path_cost
1080 did_add_update_path_to_src_node
1084 let empty_node_features = NodeFeatures::empty();
1085 // Find ways (channels with destination) to reach a given node and store them
1086 // in the corresponding data structures (routing graph etc).
1087 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1088 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1089 // This data can later be helpful to optimize routing (pay lower fees).
1090 macro_rules! add_entries_to_cheapest_to_target_node {
1091 ( $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_cost: expr, $next_hops_cltv_delta: expr ) => {
1092 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1093 let was_processed = elem.was_processed;
1094 elem.was_processed = true;
1097 // Entries are added to dist in add_entry!() when there is a channel from a node.
1098 // Because there are no channels from payee, it will not have a dist entry at this point.
1099 // If we're processing any other node, it is always be the result of a channel from it.
1100 assert_eq!($node_id, payee_node_id);
1105 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1106 for details in first_channels {
1107 let candidate = CandidateRouteHop::FirstHop { details };
1108 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_cost, $next_hops_cltv_delta);
1112 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1115 &empty_node_features
1118 if !features.requires_unknown_bits() {
1119 for chan_id in $node.channels.iter() {
1120 let chan = network_channels.get(chan_id).unwrap();
1121 if !chan.features.requires_unknown_bits() {
1122 let directed_channel =
1123 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1124 let source = directed_channel.source();
1125 let target = directed_channel.target();
1126 if first_hops.is_none() || *source != our_node_id {
1127 if let Some(direction) = directed_channel.direction() {
1128 if direction.enabled {
1129 let candidate = CandidateRouteHop::PublicHop {
1130 info: directed_channel,
1131 short_channel_id: *chan_id,
1133 add_entry!(candidate, *source, *target, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_cost, $next_hops_cltv_delta);
1144 let mut payment_paths = Vec::<PaymentPath>::new();
1146 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1147 'paths_collection: loop {
1148 // For every new path, start from scratch, except for available_channel_liquidities, which
1149 // will improve the further iterations of path finding, and first_hop_targets.
1152 hit_minimum_limit = false;
1154 // If first hop is a private channel and the only way to reach the payee, this is the only
1155 // place where it could be added.
1156 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1157 for details in first_channels {
1158 let candidate = CandidateRouteHop::FirstHop { details };
1159 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1160 log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1164 // Add the payee as a target, so that the payee-to-payer
1165 // search algorithm knows what to start with.
1166 match network_nodes.get(&payee_node_id) {
1167 // The payee is not in our network graph, so nothing to add here.
1168 // There is still a chance of reaching them via last_hops though,
1169 // so don't yet fail the payment here.
1170 // If not, targets.pop() will not even let us enter the loop in step 2.
1173 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1178 // If a caller provided us with last hops, add them to routing targets. Since this happens
1179 // earlier than general path finding, they will be somewhat prioritized, although currently
1180 // it matters only if the fees are exactly the same.
1181 for route in payee.route_hints.iter().filter(|route| !route.0.is_empty()) {
1182 let first_hop_in_route = &(route.0)[0];
1183 let have_hop_src_in_graph =
1184 // Only add the hops in this route to our candidate set if either
1185 // we have a direct channel to the first hop or the first hop is
1186 // in the regular network graph.
1187 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1188 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1189 if have_hop_src_in_graph {
1190 // We start building the path from reverse, i.e., from payee
1191 // to the first RouteHintHop in the path.
1192 let hop_iter = route.0.iter().rev();
1193 let prev_hop_iter = core::iter::once(&payee.pubkey).chain(
1194 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1195 let mut hop_used = true;
1196 let mut aggregate_next_hops_fee_msat: u64 = 0;
1197 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1198 let mut aggregate_next_hops_path_cost: u64 = 0;
1199 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1201 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1202 let source = NodeId::from_pubkey(&hop.src_node_id);
1203 let target = NodeId::from_pubkey(&prev_hop_id);
1204 let candidate = network_channels
1205 .get(&hop.short_channel_id)
1206 .and_then(|channel| channel.as_directed_to(&target))
1207 .and_then(|channel| channel.direction().map(|_| channel))
1208 .map(|info| CandidateRouteHop::PublicHop {
1210 short_channel_id: hop.short_channel_id,
1212 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1214 let params = ChannelUseParameters {
1215 amount_msat: final_value_msat,
1216 inflight_htlc_msat: 0,
1217 fees_msat: cmp::max(aggregate_next_hops_fee_msat, aggregate_next_hops_path_htlc_minimum_msat),
1218 effective_capacity_msat: candidate.effective_capacity().as_msat(),
1220 let channel_cost = scorer.channel_cost(hop.short_channel_id, &source, &target, params);
1221 aggregate_next_hops_path_cost = aggregate_next_hops_path_cost
1222 .checked_add(channel_cost)
1223 .unwrap_or_else(|| u64::max_value());
1225 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1226 .checked_add(hop.cltv_expiry_delta as u32)
1227 .unwrap_or_else(|| u32::max_value());
1229 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_cost, aggregate_next_hops_cltv_delta) {
1230 // If this hop was not used then there is no use checking the preceding hops
1231 // in the RouteHint. We can break by just searching for a direct channel between
1232 // last checked hop and first_hop_targets
1236 // Searching for a direct channel between last checked hop and first_hop_targets
1237 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1238 for details in first_channels {
1239 let candidate = CandidateRouteHop::FirstHop { details };
1240 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_cost, aggregate_next_hops_cltv_delta);
1248 // In the next values of the iterator, the aggregate fees already reflects
1249 // the sum of value sent from payer (final_value_msat) and routing fees
1250 // for the last node in the RouteHint. We need to just add the fees to
1251 // route through the current node so that the preceeding node (next iteration)
1253 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1254 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1255 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1257 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1258 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1259 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1260 .checked_add(hop_htlc_minimum_msat_inc);
1261 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1263 if idx == route.0.len() - 1 {
1264 // The last hop in this iterator is the first hop in
1265 // overall RouteHint.
1266 // If this hop connects to a node with which we have a direct channel,
1267 // ignore the network graph and, if the last hop was added, add our
1268 // direct channel to the candidate set.
1270 // Note that we *must* check if the last hop was added as `add_entry`
1271 // always assumes that the third argument is a node to which we have a
1273 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1274 for details in first_channels {
1275 let candidate = CandidateRouteHop::FirstHop { details };
1276 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_cost, aggregate_next_hops_cltv_delta);
1284 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1286 // At this point, targets are filled with the data from first and
1287 // last hops communicated by the caller, and the payment receiver.
1288 let mut found_new_path = false;
1291 // If this loop terminates due the exhaustion of targets, two situations are possible:
1292 // - not enough outgoing liquidity:
1293 // 0 < already_collected_value_msat < final_value_msat
1294 // - enough outgoing liquidity:
1295 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1296 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1297 // paths_collection will be stopped because found_new_path==false.
1298 // This is not necessarily a routing failure.
1299 'path_construction: while let Some(RouteGraphNode { node_id, lowest_fee_to_node, total_cltv_delta, value_contribution_msat, path_htlc_minimum_msat, path_cost, .. }) = targets.pop() {
1301 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1302 // traversing the graph and arrange the path out of what we found.
1303 if node_id == our_node_id {
1304 let mut new_entry = dist.remove(&our_node_id).unwrap();
1305 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
1308 let mut features_set = false;
1309 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1310 for details in first_channels {
1311 if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1312 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1313 features_set = true;
1319 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1320 if let Some(node_info) = node.announcement_info.as_ref() {
1321 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1323 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
1326 // We should be able to fill in features for everything except the last
1327 // hop, if the last hop was provided via a BOLT 11 invoice (though we
1328 // should be able to extend it further as BOLT 11 does have feature
1329 // flags for the last hop node itself).
1330 assert!(ordered_hops.last().unwrap().0.node_id == payee_node_id);
1334 // Means we succesfully traversed from the payer to the payee, now
1335 // save this path for the payment route. Also, update the liquidity
1336 // remaining on the used hops, so that we take them into account
1337 // while looking for more paths.
1338 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1342 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1343 Some(payment_hop) => payment_hop,
1344 // We can't arrive at None because, if we ever add an entry to targets,
1345 // we also fill in the entry in dist (see add_entry!).
1346 None => unreachable!(),
1348 // We "propagate" the fees one hop backward (topologically) here,
1349 // so that fees paid for a HTLC forwarding on the current channel are
1350 // associated with the previous channel (where they will be subtracted).
1351 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1352 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
1354 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1355 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1357 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: {:?}",
1358 ordered_hops.len(), value_contribution_msat, ordered_hops);
1360 let mut payment_path = PaymentPath {hops: ordered_hops};
1362 // We could have possibly constructed a slightly inconsistent path: since we reduce
1363 // value being transferred along the way, we could have violated htlc_minimum_msat
1364 // on some channels we already passed (assuming dest->source direction). Here, we
1365 // recompute the fees again, so that if that's the case, we match the currently
1366 // underpaid htlc_minimum_msat with fees.
1367 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1369 // Since a path allows to transfer as much value as
1370 // the smallest channel it has ("bottleneck"), we should recompute
1371 // the fees so sender HTLC don't overpay fees when traversing
1372 // larger channels than the bottleneck. This may happen because
1373 // when we were selecting those channels we were not aware how much value
1374 // this path will transfer, and the relative fee for them
1375 // might have been computed considering a larger value.
1376 // Remember that we used these channels so that we don't rely
1377 // on the same liquidity in future paths.
1378 let mut prevented_redundant_path_selection = false;
1379 let prev_hop_iter = core::iter::once(&our_node_id)
1380 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1381 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1382 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1383 let available_liquidity_msat = available_channel_liquidities
1384 .get_mut(&(hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1386 .reduce_by(spent_on_hop_msat)
1388 if available_liquidity_msat == 0 {
1389 // If this path used all of this channel's available liquidity, we know
1390 // this path will not be selected again in the next loop iteration.
1391 prevented_redundant_path_selection = true;
1394 if !prevented_redundant_path_selection {
1395 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1396 // we'll probably end up picking the same path again on the next iteration.
1397 // Decrease the available liquidity of a hop in the middle of the path.
1398 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.candidate.short_channel_id();
1399 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1400 available_channel_liquidities.get_mut(&(victim_scid, false)).map(|l| l.exhaust());
1401 available_channel_liquidities.get_mut(&(victim_scid, true)).map(|l| l.exhaust());
1404 // Track the total amount all our collected paths allow to send so that we:
1405 // - know when to stop looking for more paths
1406 // - know which of the hops are useless considering how much more sats we need
1407 // (contributes_sufficient_value)
1408 already_collected_value_msat += value_contribution_msat;
1410 payment_paths.push(payment_path);
1411 found_new_path = true;
1412 break 'path_construction;
1415 // If we found a path back to the payee, we shouldn't try to process it again. This is
1416 // the equivalent of the `elem.was_processed` check in
1417 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1418 if node_id == payee_node_id { continue 'path_construction; }
1420 // Otherwise, since the current target node is not us,
1421 // keep "unrolling" the payment graph from payee to payer by
1422 // finding a way to reach the current target from the payer side.
1423 match network_nodes.get(&node_id) {
1426 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, path_cost, total_cltv_delta);
1432 // If we don't support MPP, no use trying to gather more value ever.
1433 break 'paths_collection;
1437 // Stop either when the recommended value is reached or if no new path was found in this
1439 // In the latter case, making another path finding attempt won't help,
1440 // because we deterministically terminated the search due to low liquidity.
1441 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1442 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1443 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1444 break 'paths_collection;
1445 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1446 // Further, if this was our first walk of the graph, and we weren't limited by an
1447 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1448 // limited by an htlc_minimum_msat value, find another path with a higher value,
1449 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1450 // still keeping a lower total fee than this path.
1451 if !hit_minimum_limit {
1452 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1453 break 'paths_collection;
1455 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1456 path_value_msat = recommended_value_msat;
1461 if payment_paths.len() == 0 {
1462 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1465 if already_collected_value_msat < final_value_msat {
1466 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1469 // Sort by total fees and take the best paths.
1470 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1471 if payment_paths.len() > 50 {
1472 payment_paths.truncate(50);
1475 // Draw multiple sufficient routes by randomly combining the selected paths.
1476 let mut drawn_routes = Vec::new();
1477 for i in 0..payment_paths.len() {
1478 let mut cur_route = Vec::<PaymentPath>::new();
1479 let mut aggregate_route_value_msat = 0;
1482 // TODO: real random shuffle
1483 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1484 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1487 for payment_path in cur_payment_paths {
1488 cur_route.push(payment_path.clone());
1489 aggregate_route_value_msat += payment_path.get_value_msat();
1490 if aggregate_route_value_msat > final_value_msat {
1491 // Last path likely overpaid. Substract it from the most expensive
1492 // (in terms of proportional fee) path in this route and recompute fees.
1493 // This might be not the most economically efficient way, but fewer paths
1494 // also makes routing more reliable.
1495 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1497 // First, drop some expensive low-value paths entirely if possible.
1498 // Sort by value so that we drop many really-low values first, since
1499 // fewer paths is better: the payment is less likely to fail.
1500 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1501 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1502 cur_route.sort_by_key(|path| path.get_value_msat());
1503 // We should make sure that at least 1 path left.
1504 let mut paths_left = cur_route.len();
1505 cur_route.retain(|path| {
1506 if paths_left == 1 {
1509 let mut keep = true;
1510 let path_value_msat = path.get_value_msat();
1511 if path_value_msat <= overpaid_value_msat {
1513 overpaid_value_msat -= path_value_msat;
1519 if overpaid_value_msat == 0 {
1523 assert!(cur_route.len() > 0);
1526 // Now, substract the overpaid value from the most-expensive path.
1527 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1528 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1529 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1530 let expensive_payment_path = cur_route.first_mut().unwrap();
1531 // We already dropped all the small channels above, meaning all the
1532 // remaining channels are larger than remaining overpaid_value_msat.
1533 // Thus, this can't be negative.
1534 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1535 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1539 drawn_routes.push(cur_route);
1543 // Select the best route by lowest total fee.
1544 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1545 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1546 for payment_path in drawn_routes.first().unwrap() {
1547 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1549 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)})?,
1550 node_features: node_features.clone(),
1551 short_channel_id: payment_hop.candidate.short_channel_id(),
1552 channel_features: payment_hop.candidate.features(),
1553 fee_msat: payment_hop.fee_msat,
1554 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1556 }).collect::<Vec<_>>();
1557 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1558 // applicable for the previous hop.
1559 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1560 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1562 selected_paths.push(path);
1565 if let Some(features) = &payee.features {
1566 for path in selected_paths.iter_mut() {
1567 if let Ok(route_hop) = path.last_mut().unwrap() {
1568 route_hop.node_features = features.to_context();
1574 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1575 payee: Some(payee.clone()),
1577 log_info!(logger, "Got route to {}: {}", payee.pubkey, log_route!(route));
1583 use routing::scoring::{ChannelUseParameters, ProbabilisticScorer, ProbabilisticScoringParameters, Score};
1584 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler, NodeId};
1585 use routing::router::{get_route, Payee, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees};
1586 use chain::transaction::OutPoint;
1587 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1588 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1589 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1590 use ln::channelmanager;
1591 use util::test_utils;
1592 use util::ser::Writeable;
1594 use util::ser::Writer;
1596 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1597 use bitcoin::hashes::Hash;
1598 use bitcoin::network::constants::Network;
1599 use bitcoin::blockdata::constants::genesis_block;
1600 use bitcoin::blockdata::script::Builder;
1601 use bitcoin::blockdata::opcodes;
1602 use bitcoin::blockdata::transaction::TxOut;
1606 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1607 use bitcoin::secp256k1::{Secp256k1, All};
1610 use sync::{self, Arc};
1612 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1613 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1614 channelmanager::ChannelDetails {
1615 channel_id: [0; 32],
1616 counterparty: channelmanager::ChannelCounterparty {
1619 unspendable_punishment_reserve: 0,
1620 forwarding_info: None,
1622 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1624 channel_value_satoshis: 0,
1627 outbound_capacity_msat,
1628 inbound_capacity_msat: 42,
1629 unspendable_punishment_reserve: None,
1630 confirmations_required: None,
1631 force_close_spend_delay: None,
1632 is_outbound: true, is_funding_locked: true,
1633 is_usable: true, is_public: true,
1637 // Using the same keys for LN and BTC ids
1639 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1640 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1642 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1643 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1645 let unsigned_announcement = UnsignedChannelAnnouncement {
1647 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1651 bitcoin_key_1: node_id_1,
1652 bitcoin_key_2: node_id_2,
1653 excess_data: Vec::new(),
1656 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1657 let valid_announcement = ChannelAnnouncement {
1658 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1659 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1660 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1661 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1662 contents: unsigned_announcement.clone(),
1664 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1665 Ok(res) => assert!(res),
1671 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1672 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1674 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1675 let valid_channel_update = ChannelUpdate {
1676 signature: secp_ctx.sign(&msghash, node_privkey),
1677 contents: update.clone()
1680 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1681 Ok(res) => assert!(res),
1686 fn add_or_update_node(
1687 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1688 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1690 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1691 let unsigned_announcement = UnsignedNodeAnnouncement {
1697 addresses: Vec::new(),
1698 excess_address_data: Vec::new(),
1699 excess_data: Vec::new(),
1701 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1702 let valid_announcement = NodeAnnouncement {
1703 signature: secp_ctx.sign(&msghash, node_privkey),
1704 contents: unsigned_announcement.clone()
1707 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1713 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1714 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1715 SecretKey::from_slice(&hex::decode(format!("{:02}", i).repeat(32)).unwrap()[..]).unwrap()
1718 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1720 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1721 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1723 (our_privkey, our_id, privkeys, pubkeys)
1726 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1727 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1728 // test for it later.
1729 let idx = (id - 1) * 2 + 1;
1731 vec![1 << (idx - 8*3), 0, 0, 0]
1732 } else if idx > 8*2 {
1733 vec![1 << (idx - 8*2), 0, 0]
1734 } else if idx > 8*1 {
1735 vec![1 << (idx - 8*1), 0]
1741 fn build_graph() -> (
1743 sync::Arc<NetworkGraph>,
1744 NetGraphMsgHandler<sync::Arc<NetworkGraph>, sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>,
1745 sync::Arc<test_utils::TestChainSource>,
1746 sync::Arc<test_utils::TestLogger>,
1748 let secp_ctx = Secp256k1::new();
1749 let logger = Arc::new(test_utils::TestLogger::new());
1750 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1751 let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
1752 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
1753 // Build network from our_id to node6:
1755 // -1(1)2- node0 -1(3)2-
1757 // our_id -1(12)2- node7 -1(13)2--- node2
1759 // -1(2)2- node1 -1(4)2-
1762 // chan1 1-to-2: disabled
1763 // chan1 2-to-1: enabled, 0 fee
1765 // chan2 1-to-2: enabled, ignored fee
1766 // chan2 2-to-1: enabled, 0 fee
1768 // chan3 1-to-2: enabled, 0 fee
1769 // chan3 2-to-1: enabled, 100 msat fee
1771 // chan4 1-to-2: enabled, 100% fee
1772 // chan4 2-to-1: enabled, 0 fee
1774 // chan12 1-to-2: enabled, ignored fee
1775 // chan12 2-to-1: enabled, 0 fee
1777 // chan13 1-to-2: enabled, 200% fee
1778 // chan13 2-to-1: enabled, 0 fee
1781 // -1(5)2- node3 -1(8)2--
1785 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1787 // -1(7)2- node5 -1(10)2-
1789 // Channels 5, 8, 9 and 10 are private channels.
1791 // chan5 1-to-2: enabled, 100 msat fee
1792 // chan5 2-to-1: enabled, 0 fee
1794 // chan6 1-to-2: enabled, 0 fee
1795 // chan6 2-to-1: enabled, 0 fee
1797 // chan7 1-to-2: enabled, 100% fee
1798 // chan7 2-to-1: enabled, 0 fee
1800 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1801 // chan8 2-to-1: enabled, 0 fee
1803 // chan9 1-to-2: enabled, 1001 msat fee
1804 // chan9 2-to-1: enabled, 0 fee
1806 // chan10 1-to-2: enabled, 0 fee
1807 // chan10 2-to-1: enabled, 0 fee
1809 // chan11 1-to-2: enabled, 0 fee
1810 // chan11 2-to-1: enabled, 0 fee
1812 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1814 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1815 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1816 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1817 short_channel_id: 1,
1820 cltv_expiry_delta: 0,
1821 htlc_minimum_msat: 0,
1822 htlc_maximum_msat: OptionalField::Absent,
1824 fee_proportional_millionths: 0,
1825 excess_data: Vec::new()
1828 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1830 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1831 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1832 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1833 short_channel_id: 2,
1836 cltv_expiry_delta: (5 << 4) | 3,
1837 htlc_minimum_msat: 0,
1838 htlc_maximum_msat: OptionalField::Absent,
1839 fee_base_msat: u32::max_value(),
1840 fee_proportional_millionths: u32::max_value(),
1841 excess_data: Vec::new()
1843 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1844 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1845 short_channel_id: 2,
1848 cltv_expiry_delta: 0,
1849 htlc_minimum_msat: 0,
1850 htlc_maximum_msat: OptionalField::Absent,
1852 fee_proportional_millionths: 0,
1853 excess_data: Vec::new()
1856 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1858 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1859 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1860 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1861 short_channel_id: 12,
1864 cltv_expiry_delta: (5 << 4) | 3,
1865 htlc_minimum_msat: 0,
1866 htlc_maximum_msat: OptionalField::Absent,
1867 fee_base_msat: u32::max_value(),
1868 fee_proportional_millionths: u32::max_value(),
1869 excess_data: Vec::new()
1871 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1872 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1873 short_channel_id: 12,
1876 cltv_expiry_delta: 0,
1877 htlc_minimum_msat: 0,
1878 htlc_maximum_msat: OptionalField::Absent,
1880 fee_proportional_millionths: 0,
1881 excess_data: Vec::new()
1884 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1886 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1887 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1888 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1889 short_channel_id: 3,
1892 cltv_expiry_delta: (3 << 4) | 1,
1893 htlc_minimum_msat: 0,
1894 htlc_maximum_msat: OptionalField::Absent,
1896 fee_proportional_millionths: 0,
1897 excess_data: Vec::new()
1899 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1900 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1901 short_channel_id: 3,
1904 cltv_expiry_delta: (3 << 4) | 2,
1905 htlc_minimum_msat: 0,
1906 htlc_maximum_msat: OptionalField::Absent,
1908 fee_proportional_millionths: 0,
1909 excess_data: Vec::new()
1912 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1913 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1914 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1915 short_channel_id: 4,
1918 cltv_expiry_delta: (4 << 4) | 1,
1919 htlc_minimum_msat: 0,
1920 htlc_maximum_msat: OptionalField::Absent,
1922 fee_proportional_millionths: 1000000,
1923 excess_data: Vec::new()
1925 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1926 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1927 short_channel_id: 4,
1930 cltv_expiry_delta: (4 << 4) | 2,
1931 htlc_minimum_msat: 0,
1932 htlc_maximum_msat: OptionalField::Absent,
1934 fee_proportional_millionths: 0,
1935 excess_data: Vec::new()
1938 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
1939 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1940 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1941 short_channel_id: 13,
1944 cltv_expiry_delta: (13 << 4) | 1,
1945 htlc_minimum_msat: 0,
1946 htlc_maximum_msat: OptionalField::Absent,
1948 fee_proportional_millionths: 2000000,
1949 excess_data: Vec::new()
1951 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1952 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1953 short_channel_id: 13,
1956 cltv_expiry_delta: (13 << 4) | 2,
1957 htlc_minimum_msat: 0,
1958 htlc_maximum_msat: OptionalField::Absent,
1960 fee_proportional_millionths: 0,
1961 excess_data: Vec::new()
1964 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
1966 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
1967 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1968 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1969 short_channel_id: 6,
1972 cltv_expiry_delta: (6 << 4) | 1,
1973 htlc_minimum_msat: 0,
1974 htlc_maximum_msat: OptionalField::Absent,
1976 fee_proportional_millionths: 0,
1977 excess_data: Vec::new()
1979 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1980 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1981 short_channel_id: 6,
1984 cltv_expiry_delta: (6 << 4) | 2,
1985 htlc_minimum_msat: 0,
1986 htlc_maximum_msat: OptionalField::Absent,
1988 fee_proportional_millionths: 0,
1989 excess_data: Vec::new(),
1992 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
1993 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
1994 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1995 short_channel_id: 11,
1998 cltv_expiry_delta: (11 << 4) | 1,
1999 htlc_minimum_msat: 0,
2000 htlc_maximum_msat: OptionalField::Absent,
2002 fee_proportional_millionths: 0,
2003 excess_data: Vec::new()
2005 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2006 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2007 short_channel_id: 11,
2010 cltv_expiry_delta: (11 << 4) | 2,
2011 htlc_minimum_msat: 0,
2012 htlc_maximum_msat: OptionalField::Absent,
2014 fee_proportional_millionths: 0,
2015 excess_data: Vec::new()
2018 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2020 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2022 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2023 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2024 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2025 short_channel_id: 7,
2028 cltv_expiry_delta: (7 << 4) | 1,
2029 htlc_minimum_msat: 0,
2030 htlc_maximum_msat: OptionalField::Absent,
2032 fee_proportional_millionths: 1000000,
2033 excess_data: Vec::new()
2035 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2036 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2037 short_channel_id: 7,
2040 cltv_expiry_delta: (7 << 4) | 2,
2041 htlc_minimum_msat: 0,
2042 htlc_maximum_msat: OptionalField::Absent,
2044 fee_proportional_millionths: 0,
2045 excess_data: Vec::new()
2048 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2050 (secp_ctx, network_graph, net_graph_msg_handler, chain_monitor, logger)
2054 fn simple_route_test() {
2055 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2056 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2057 let payee = Payee::from_node_id(nodes[2]);
2058 let scorer = test_utils::TestScorer::with_penalty(0);
2060 // Simple route to 2 via 1
2062 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, None, 0, 42, Arc::clone(&logger), &scorer) {
2063 assert_eq!(err, "Cannot send a payment of 0 msat");
2064 } else { panic!(); }
2066 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2067 assert_eq!(route.paths[0].len(), 2);
2069 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2070 assert_eq!(route.paths[0][0].short_channel_id, 2);
2071 assert_eq!(route.paths[0][0].fee_msat, 100);
2072 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2073 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2074 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2076 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2077 assert_eq!(route.paths[0][1].short_channel_id, 4);
2078 assert_eq!(route.paths[0][1].fee_msat, 100);
2079 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2080 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2081 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2085 fn invalid_first_hop_test() {
2086 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2087 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2088 let payee = Payee::from_node_id(nodes[2]);
2089 let scorer = test_utils::TestScorer::with_penalty(0);
2091 // Simple route to 2 via 1
2093 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2095 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer) {
2096 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2097 } else { panic!(); }
2099 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2100 assert_eq!(route.paths[0].len(), 2);
2104 fn htlc_minimum_test() {
2105 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2106 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2107 let payee = Payee::from_node_id(nodes[2]);
2108 let scorer = test_utils::TestScorer::with_penalty(0);
2110 // Simple route to 2 via 1
2112 // Disable other paths
2113 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2114 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2115 short_channel_id: 12,
2117 flags: 2, // to disable
2118 cltv_expiry_delta: 0,
2119 htlc_minimum_msat: 0,
2120 htlc_maximum_msat: OptionalField::Absent,
2122 fee_proportional_millionths: 0,
2123 excess_data: Vec::new()
2125 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2126 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2127 short_channel_id: 3,
2129 flags: 2, // to disable
2130 cltv_expiry_delta: 0,
2131 htlc_minimum_msat: 0,
2132 htlc_maximum_msat: OptionalField::Absent,
2134 fee_proportional_millionths: 0,
2135 excess_data: Vec::new()
2137 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2138 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2139 short_channel_id: 13,
2141 flags: 2, // to disable
2142 cltv_expiry_delta: 0,
2143 htlc_minimum_msat: 0,
2144 htlc_maximum_msat: OptionalField::Absent,
2146 fee_proportional_millionths: 0,
2147 excess_data: Vec::new()
2149 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2150 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2151 short_channel_id: 6,
2153 flags: 2, // to disable
2154 cltv_expiry_delta: 0,
2155 htlc_minimum_msat: 0,
2156 htlc_maximum_msat: OptionalField::Absent,
2158 fee_proportional_millionths: 0,
2159 excess_data: Vec::new()
2161 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2162 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2163 short_channel_id: 7,
2165 flags: 2, // to disable
2166 cltv_expiry_delta: 0,
2167 htlc_minimum_msat: 0,
2168 htlc_maximum_msat: OptionalField::Absent,
2170 fee_proportional_millionths: 0,
2171 excess_data: Vec::new()
2174 // Check against amount_to_transfer_over_msat.
2175 // Set minimal HTLC of 200_000_000 msat.
2176 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2177 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2178 short_channel_id: 2,
2181 cltv_expiry_delta: 0,
2182 htlc_minimum_msat: 200_000_000,
2183 htlc_maximum_msat: OptionalField::Absent,
2185 fee_proportional_millionths: 0,
2186 excess_data: Vec::new()
2189 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2191 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2192 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2193 short_channel_id: 4,
2196 cltv_expiry_delta: 0,
2197 htlc_minimum_msat: 0,
2198 htlc_maximum_msat: OptionalField::Present(199_999_999),
2200 fee_proportional_millionths: 0,
2201 excess_data: Vec::new()
2204 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2205 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, None, 199_999_999, 42, Arc::clone(&logger), &scorer) {
2206 assert_eq!(err, "Failed to find a path to the given destination");
2207 } else { panic!(); }
2209 // Lift the restriction on the first hop.
2210 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2211 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2212 short_channel_id: 2,
2215 cltv_expiry_delta: 0,
2216 htlc_minimum_msat: 0,
2217 htlc_maximum_msat: OptionalField::Absent,
2219 fee_proportional_millionths: 0,
2220 excess_data: Vec::new()
2223 // A payment above the minimum should pass
2224 let route = get_route(&our_id, &payee, &network_graph, None, 199_999_999, 42, Arc::clone(&logger), &scorer).unwrap();
2225 assert_eq!(route.paths[0].len(), 2);
2229 fn htlc_minimum_overpay_test() {
2230 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2231 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2232 let payee = Payee::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2233 let scorer = test_utils::TestScorer::with_penalty(0);
2235 // A route to node#2 via two paths.
2236 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2237 // Thus, they can't send 60 without overpaying.
2238 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2239 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2240 short_channel_id: 2,
2243 cltv_expiry_delta: 0,
2244 htlc_minimum_msat: 35_000,
2245 htlc_maximum_msat: OptionalField::Present(40_000),
2247 fee_proportional_millionths: 0,
2248 excess_data: Vec::new()
2250 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2251 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2252 short_channel_id: 12,
2255 cltv_expiry_delta: 0,
2256 htlc_minimum_msat: 35_000,
2257 htlc_maximum_msat: OptionalField::Present(40_000),
2259 fee_proportional_millionths: 0,
2260 excess_data: Vec::new()
2264 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2265 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2266 short_channel_id: 13,
2269 cltv_expiry_delta: 0,
2270 htlc_minimum_msat: 0,
2271 htlc_maximum_msat: OptionalField::Absent,
2273 fee_proportional_millionths: 0,
2274 excess_data: Vec::new()
2276 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2277 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2278 short_channel_id: 4,
2281 cltv_expiry_delta: 0,
2282 htlc_minimum_msat: 0,
2283 htlc_maximum_msat: OptionalField::Absent,
2285 fee_proportional_millionths: 0,
2286 excess_data: Vec::new()
2289 // Disable other paths
2290 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2291 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2292 short_channel_id: 1,
2294 flags: 2, // to disable
2295 cltv_expiry_delta: 0,
2296 htlc_minimum_msat: 0,
2297 htlc_maximum_msat: OptionalField::Absent,
2299 fee_proportional_millionths: 0,
2300 excess_data: Vec::new()
2303 let route = get_route(&our_id, &payee, &network_graph, None, 60_000, 42, Arc::clone(&logger), &scorer).unwrap();
2304 // Overpay fees to hit htlc_minimum_msat.
2305 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2306 // TODO: this could be better balanced to overpay 10k and not 15k.
2307 assert_eq!(overpaid_fees, 15_000);
2309 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2310 // while taking even more fee to match htlc_minimum_msat.
2311 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2312 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2313 short_channel_id: 12,
2316 cltv_expiry_delta: 0,
2317 htlc_minimum_msat: 65_000,
2318 htlc_maximum_msat: OptionalField::Present(80_000),
2320 fee_proportional_millionths: 0,
2321 excess_data: Vec::new()
2323 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2324 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2325 short_channel_id: 2,
2328 cltv_expiry_delta: 0,
2329 htlc_minimum_msat: 0,
2330 htlc_maximum_msat: OptionalField::Absent,
2332 fee_proportional_millionths: 0,
2333 excess_data: Vec::new()
2335 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2336 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2337 short_channel_id: 4,
2340 cltv_expiry_delta: 0,
2341 htlc_minimum_msat: 0,
2342 htlc_maximum_msat: OptionalField::Absent,
2344 fee_proportional_millionths: 100_000,
2345 excess_data: Vec::new()
2348 let route = get_route(&our_id, &payee, &network_graph, None, 60_000, 42, Arc::clone(&logger), &scorer).unwrap();
2349 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2350 assert_eq!(route.paths.len(), 1);
2351 assert_eq!(route.paths[0][0].short_channel_id, 12);
2352 let fees = route.paths[0][0].fee_msat;
2353 assert_eq!(fees, 5_000);
2355 let route = get_route(&our_id, &payee, &network_graph, None, 50_000, 42, Arc::clone(&logger), &scorer).unwrap();
2356 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2357 // the other channel.
2358 assert_eq!(route.paths.len(), 1);
2359 assert_eq!(route.paths[0][0].short_channel_id, 2);
2360 let fees = route.paths[0][0].fee_msat;
2361 assert_eq!(fees, 5_000);
2365 fn disable_channels_test() {
2366 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2367 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2368 let payee = Payee::from_node_id(nodes[2]);
2369 let scorer = test_utils::TestScorer::with_penalty(0);
2371 // // Disable channels 4 and 12 by flags=2
2372 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2373 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2374 short_channel_id: 4,
2376 flags: 2, // to disable
2377 cltv_expiry_delta: 0,
2378 htlc_minimum_msat: 0,
2379 htlc_maximum_msat: OptionalField::Absent,
2381 fee_proportional_millionths: 0,
2382 excess_data: Vec::new()
2384 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2385 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2386 short_channel_id: 12,
2388 flags: 2, // to disable
2389 cltv_expiry_delta: 0,
2390 htlc_minimum_msat: 0,
2391 htlc_maximum_msat: OptionalField::Absent,
2393 fee_proportional_millionths: 0,
2394 excess_data: Vec::new()
2397 // If all the channels require some features we don't understand, route should fail
2398 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer) {
2399 assert_eq!(err, "Failed to find a path to the given destination");
2400 } else { panic!(); }
2402 // If we specify a channel to node7, that overrides our local channel view and that gets used
2403 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2404 let route = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer).unwrap();
2405 assert_eq!(route.paths[0].len(), 2);
2407 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2408 assert_eq!(route.paths[0][0].short_channel_id, 42);
2409 assert_eq!(route.paths[0][0].fee_msat, 200);
2410 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2411 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2412 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2414 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2415 assert_eq!(route.paths[0][1].short_channel_id, 13);
2416 assert_eq!(route.paths[0][1].fee_msat, 100);
2417 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2418 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2419 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2423 fn disable_node_test() {
2424 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2425 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2426 let payee = Payee::from_node_id(nodes[2]);
2427 let scorer = test_utils::TestScorer::with_penalty(0);
2429 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2430 let unknown_features = NodeFeatures::known().set_unknown_feature_required();
2431 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2432 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2433 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2435 // If all nodes require some features we don't understand, route should fail
2436 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer) {
2437 assert_eq!(err, "Failed to find a path to the given destination");
2438 } else { panic!(); }
2440 // If we specify a channel to node7, that overrides our local channel view and that gets used
2441 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2442 let route = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer).unwrap();
2443 assert_eq!(route.paths[0].len(), 2);
2445 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2446 assert_eq!(route.paths[0][0].short_channel_id, 42);
2447 assert_eq!(route.paths[0][0].fee_msat, 200);
2448 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2449 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2450 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2452 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2453 assert_eq!(route.paths[0][1].short_channel_id, 13);
2454 assert_eq!(route.paths[0][1].fee_msat, 100);
2455 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2456 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2457 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2459 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2460 // naively) assume that the user checked the feature bits on the invoice, which override
2461 // the node_announcement.
2465 fn our_chans_test() {
2466 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2467 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2468 let scorer = test_utils::TestScorer::with_penalty(0);
2470 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2471 let payee = Payee::from_node_id(nodes[0]);
2472 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2473 assert_eq!(route.paths[0].len(), 3);
2475 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2476 assert_eq!(route.paths[0][0].short_channel_id, 2);
2477 assert_eq!(route.paths[0][0].fee_msat, 200);
2478 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2479 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2480 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2482 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2483 assert_eq!(route.paths[0][1].short_channel_id, 4);
2484 assert_eq!(route.paths[0][1].fee_msat, 100);
2485 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2486 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2487 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2489 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2490 assert_eq!(route.paths[0][2].short_channel_id, 3);
2491 assert_eq!(route.paths[0][2].fee_msat, 100);
2492 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2493 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2494 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2496 // If we specify a channel to node7, that overrides our local channel view and that gets used
2497 let payee = Payee::from_node_id(nodes[2]);
2498 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2499 let route = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer).unwrap();
2500 assert_eq!(route.paths[0].len(), 2);
2502 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2503 assert_eq!(route.paths[0][0].short_channel_id, 42);
2504 assert_eq!(route.paths[0][0].fee_msat, 200);
2505 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2506 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2507 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2509 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2510 assert_eq!(route.paths[0][1].short_channel_id, 13);
2511 assert_eq!(route.paths[0][1].fee_msat, 100);
2512 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2513 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2514 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2517 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2518 let zero_fees = RoutingFees {
2520 proportional_millionths: 0,
2522 vec![RouteHint(vec![RouteHintHop {
2523 src_node_id: nodes[3],
2524 short_channel_id: 8,
2526 cltv_expiry_delta: (8 << 4) | 1,
2527 htlc_minimum_msat: None,
2528 htlc_maximum_msat: None,
2530 ]), RouteHint(vec![RouteHintHop {
2531 src_node_id: nodes[4],
2532 short_channel_id: 9,
2535 proportional_millionths: 0,
2537 cltv_expiry_delta: (9 << 4) | 1,
2538 htlc_minimum_msat: None,
2539 htlc_maximum_msat: None,
2540 }]), RouteHint(vec![RouteHintHop {
2541 src_node_id: nodes[5],
2542 short_channel_id: 10,
2544 cltv_expiry_delta: (10 << 4) | 1,
2545 htlc_minimum_msat: None,
2546 htlc_maximum_msat: None,
2550 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2551 let zero_fees = RoutingFees {
2553 proportional_millionths: 0,
2555 vec![RouteHint(vec![RouteHintHop {
2556 src_node_id: nodes[2],
2557 short_channel_id: 5,
2560 proportional_millionths: 0,
2562 cltv_expiry_delta: (5 << 4) | 1,
2563 htlc_minimum_msat: None,
2564 htlc_maximum_msat: None,
2566 src_node_id: nodes[3],
2567 short_channel_id: 8,
2569 cltv_expiry_delta: (8 << 4) | 1,
2570 htlc_minimum_msat: None,
2571 htlc_maximum_msat: None,
2573 ]), RouteHint(vec![RouteHintHop {
2574 src_node_id: nodes[4],
2575 short_channel_id: 9,
2578 proportional_millionths: 0,
2580 cltv_expiry_delta: (9 << 4) | 1,
2581 htlc_minimum_msat: None,
2582 htlc_maximum_msat: None,
2583 }]), RouteHint(vec![RouteHintHop {
2584 src_node_id: nodes[5],
2585 short_channel_id: 10,
2587 cltv_expiry_delta: (10 << 4) | 1,
2588 htlc_minimum_msat: None,
2589 htlc_maximum_msat: None,
2594 fn partial_route_hint_test() {
2595 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2596 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2597 let scorer = test_utils::TestScorer::with_penalty(0);
2599 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2600 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2601 // RouteHint may be partially used by the algo to build the best path.
2603 // First check that last hop can't have its source as the payee.
2604 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2605 src_node_id: nodes[6],
2606 short_channel_id: 8,
2609 proportional_millionths: 0,
2611 cltv_expiry_delta: (8 << 4) | 1,
2612 htlc_minimum_msat: None,
2613 htlc_maximum_msat: None,
2616 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2617 invalid_last_hops.push(invalid_last_hop);
2619 let payee = Payee::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2620 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer) {
2621 assert_eq!(err, "Route hint cannot have the payee as the source.");
2622 } else { panic!(); }
2625 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
2626 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2627 assert_eq!(route.paths[0].len(), 5);
2629 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2630 assert_eq!(route.paths[0][0].short_channel_id, 2);
2631 assert_eq!(route.paths[0][0].fee_msat, 100);
2632 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2633 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2634 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2636 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2637 assert_eq!(route.paths[0][1].short_channel_id, 4);
2638 assert_eq!(route.paths[0][1].fee_msat, 0);
2639 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2640 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2641 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2643 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2644 assert_eq!(route.paths[0][2].short_channel_id, 6);
2645 assert_eq!(route.paths[0][2].fee_msat, 0);
2646 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2647 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2648 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2650 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2651 assert_eq!(route.paths[0][3].short_channel_id, 11);
2652 assert_eq!(route.paths[0][3].fee_msat, 0);
2653 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2654 // If we have a peer in the node map, we'll use their features here since we don't have
2655 // a way of figuring out their features from the invoice:
2656 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2657 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2659 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2660 assert_eq!(route.paths[0][4].short_channel_id, 8);
2661 assert_eq!(route.paths[0][4].fee_msat, 100);
2662 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2663 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2664 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2667 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2668 let zero_fees = RoutingFees {
2670 proportional_millionths: 0,
2672 vec![RouteHint(vec![RouteHintHop {
2673 src_node_id: nodes[3],
2674 short_channel_id: 8,
2676 cltv_expiry_delta: (8 << 4) | 1,
2677 htlc_minimum_msat: None,
2678 htlc_maximum_msat: None,
2679 }]), RouteHint(vec![
2681 ]), RouteHint(vec![RouteHintHop {
2682 src_node_id: nodes[5],
2683 short_channel_id: 10,
2685 cltv_expiry_delta: (10 << 4) | 1,
2686 htlc_minimum_msat: None,
2687 htlc_maximum_msat: None,
2692 fn ignores_empty_last_hops_test() {
2693 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2694 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2695 let payee = Payee::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
2696 let scorer = test_utils::TestScorer::with_penalty(0);
2698 // Test handling of an empty RouteHint passed in Invoice.
2700 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2701 assert_eq!(route.paths[0].len(), 5);
2703 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2704 assert_eq!(route.paths[0][0].short_channel_id, 2);
2705 assert_eq!(route.paths[0][0].fee_msat, 100);
2706 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2707 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2708 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2710 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2711 assert_eq!(route.paths[0][1].short_channel_id, 4);
2712 assert_eq!(route.paths[0][1].fee_msat, 0);
2713 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2714 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2715 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2717 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2718 assert_eq!(route.paths[0][2].short_channel_id, 6);
2719 assert_eq!(route.paths[0][2].fee_msat, 0);
2720 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2721 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2722 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2724 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2725 assert_eq!(route.paths[0][3].short_channel_id, 11);
2726 assert_eq!(route.paths[0][3].fee_msat, 0);
2727 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2728 // If we have a peer in the node map, we'll use their features here since we don't have
2729 // a way of figuring out their features from the invoice:
2730 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2731 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2733 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2734 assert_eq!(route.paths[0][4].short_channel_id, 8);
2735 assert_eq!(route.paths[0][4].fee_msat, 100);
2736 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2737 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2738 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2741 fn multi_hint_last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2742 let zero_fees = RoutingFees {
2744 proportional_millionths: 0,
2746 vec![RouteHint(vec![RouteHintHop {
2747 src_node_id: nodes[2],
2748 short_channel_id: 5,
2751 proportional_millionths: 0,
2753 cltv_expiry_delta: (5 << 4) | 1,
2754 htlc_minimum_msat: None,
2755 htlc_maximum_msat: None,
2757 src_node_id: nodes[3],
2758 short_channel_id: 8,
2760 cltv_expiry_delta: (8 << 4) | 1,
2761 htlc_minimum_msat: None,
2762 htlc_maximum_msat: None,
2763 }]), RouteHint(vec![RouteHintHop {
2764 src_node_id: nodes[5],
2765 short_channel_id: 10,
2767 cltv_expiry_delta: (10 << 4) | 1,
2768 htlc_minimum_msat: None,
2769 htlc_maximum_msat: None,
2774 fn multi_hint_last_hops_test() {
2775 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2776 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2777 let payee = Payee::from_node_id(nodes[6]).with_route_hints(multi_hint_last_hops(&nodes));
2778 let scorer = test_utils::TestScorer::with_penalty(0);
2779 // Test through channels 2, 3, 5, 8.
2780 // Test shows that multiple hop hints are considered.
2782 // Disabling channels 6 & 7 by flags=2
2783 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2784 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2785 short_channel_id: 6,
2787 flags: 2, // to disable
2788 cltv_expiry_delta: 0,
2789 htlc_minimum_msat: 0,
2790 htlc_maximum_msat: OptionalField::Absent,
2792 fee_proportional_millionths: 0,
2793 excess_data: Vec::new()
2795 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2796 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2797 short_channel_id: 7,
2799 flags: 2, // to disable
2800 cltv_expiry_delta: 0,
2801 htlc_minimum_msat: 0,
2802 htlc_maximum_msat: OptionalField::Absent,
2804 fee_proportional_millionths: 0,
2805 excess_data: Vec::new()
2808 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2809 assert_eq!(route.paths[0].len(), 4);
2811 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2812 assert_eq!(route.paths[0][0].short_channel_id, 2);
2813 assert_eq!(route.paths[0][0].fee_msat, 200);
2814 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2815 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2816 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2818 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2819 assert_eq!(route.paths[0][1].short_channel_id, 4);
2820 assert_eq!(route.paths[0][1].fee_msat, 100);
2821 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2822 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2823 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2825 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
2826 assert_eq!(route.paths[0][2].short_channel_id, 5);
2827 assert_eq!(route.paths[0][2].fee_msat, 0);
2828 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2829 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
2830 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new());
2832 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2833 assert_eq!(route.paths[0][3].short_channel_id, 8);
2834 assert_eq!(route.paths[0][3].fee_msat, 100);
2835 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2836 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2837 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2840 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2841 let zero_fees = RoutingFees {
2843 proportional_millionths: 0,
2845 vec![RouteHint(vec![RouteHintHop {
2846 src_node_id: nodes[4],
2847 short_channel_id: 11,
2849 cltv_expiry_delta: (11 << 4) | 1,
2850 htlc_minimum_msat: None,
2851 htlc_maximum_msat: None,
2853 src_node_id: nodes[3],
2854 short_channel_id: 8,
2856 cltv_expiry_delta: (8 << 4) | 1,
2857 htlc_minimum_msat: None,
2858 htlc_maximum_msat: None,
2859 }]), RouteHint(vec![RouteHintHop {
2860 src_node_id: nodes[4],
2861 short_channel_id: 9,
2864 proportional_millionths: 0,
2866 cltv_expiry_delta: (9 << 4) | 1,
2867 htlc_minimum_msat: None,
2868 htlc_maximum_msat: None,
2869 }]), RouteHint(vec![RouteHintHop {
2870 src_node_id: nodes[5],
2871 short_channel_id: 10,
2873 cltv_expiry_delta: (10 << 4) | 1,
2874 htlc_minimum_msat: None,
2875 htlc_maximum_msat: None,
2880 fn last_hops_with_public_channel_test() {
2881 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2882 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2883 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
2884 let scorer = test_utils::TestScorer::with_penalty(0);
2885 // This test shows that public routes can be present in the invoice
2886 // which would be handled in the same manner.
2888 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2889 assert_eq!(route.paths[0].len(), 5);
2891 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2892 assert_eq!(route.paths[0][0].short_channel_id, 2);
2893 assert_eq!(route.paths[0][0].fee_msat, 100);
2894 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2895 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2896 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2898 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2899 assert_eq!(route.paths[0][1].short_channel_id, 4);
2900 assert_eq!(route.paths[0][1].fee_msat, 0);
2901 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2902 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2903 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2905 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2906 assert_eq!(route.paths[0][2].short_channel_id, 6);
2907 assert_eq!(route.paths[0][2].fee_msat, 0);
2908 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2909 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2910 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2912 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2913 assert_eq!(route.paths[0][3].short_channel_id, 11);
2914 assert_eq!(route.paths[0][3].fee_msat, 0);
2915 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2916 // If we have a peer in the node map, we'll use their features here since we don't have
2917 // a way of figuring out their features from the invoice:
2918 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2919 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2921 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2922 assert_eq!(route.paths[0][4].short_channel_id, 8);
2923 assert_eq!(route.paths[0][4].fee_msat, 100);
2924 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2925 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2926 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2930 fn our_chans_last_hop_connect_test() {
2931 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2932 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2933 let scorer = test_utils::TestScorer::with_penalty(0);
2935 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
2936 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2937 let mut last_hops = last_hops(&nodes);
2938 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2939 let route = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer).unwrap();
2940 assert_eq!(route.paths[0].len(), 2);
2942 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
2943 assert_eq!(route.paths[0][0].short_channel_id, 42);
2944 assert_eq!(route.paths[0][0].fee_msat, 0);
2945 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
2946 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2947 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2949 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
2950 assert_eq!(route.paths[0][1].short_channel_id, 8);
2951 assert_eq!(route.paths[0][1].fee_msat, 100);
2952 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2953 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2954 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2956 last_hops[0].0[0].fees.base_msat = 1000;
2958 // Revert to via 6 as the fee on 8 goes up
2959 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops);
2960 let route = get_route(&our_id, &payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
2961 assert_eq!(route.paths[0].len(), 4);
2963 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2964 assert_eq!(route.paths[0][0].short_channel_id, 2);
2965 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
2966 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2967 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2968 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2970 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2971 assert_eq!(route.paths[0][1].short_channel_id, 4);
2972 assert_eq!(route.paths[0][1].fee_msat, 100);
2973 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
2974 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2975 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2977 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
2978 assert_eq!(route.paths[0][2].short_channel_id, 7);
2979 assert_eq!(route.paths[0][2].fee_msat, 0);
2980 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
2981 // If we have a peer in the node map, we'll use their features here since we don't have
2982 // a way of figuring out their features from the invoice:
2983 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
2984 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
2986 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2987 assert_eq!(route.paths[0][3].short_channel_id, 10);
2988 assert_eq!(route.paths[0][3].fee_msat, 100);
2989 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2990 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2991 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2993 // ...but still use 8 for larger payments as 6 has a variable feerate
2994 let route = get_route(&our_id, &payee, &network_graph, None, 2000, 42, Arc::clone(&logger), &scorer).unwrap();
2995 assert_eq!(route.paths[0].len(), 5);
2997 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2998 assert_eq!(route.paths[0][0].short_channel_id, 2);
2999 assert_eq!(route.paths[0][0].fee_msat, 3000);
3000 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3001 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3002 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3004 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3005 assert_eq!(route.paths[0][1].short_channel_id, 4);
3006 assert_eq!(route.paths[0][1].fee_msat, 0);
3007 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3008 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3009 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3011 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3012 assert_eq!(route.paths[0][2].short_channel_id, 6);
3013 assert_eq!(route.paths[0][2].fee_msat, 0);
3014 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3015 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3016 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3018 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3019 assert_eq!(route.paths[0][3].short_channel_id, 11);
3020 assert_eq!(route.paths[0][3].fee_msat, 1000);
3021 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3022 // If we have a peer in the node map, we'll use their features here since we don't have
3023 // a way of figuring out their features from the invoice:
3024 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3025 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3027 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3028 assert_eq!(route.paths[0][4].short_channel_id, 8);
3029 assert_eq!(route.paths[0][4].fee_msat, 2000);
3030 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3031 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3032 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3035 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> {
3036 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3037 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3038 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3040 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3041 let last_hops = RouteHint(vec![RouteHintHop {
3042 src_node_id: middle_node_id,
3043 short_channel_id: 8,
3046 proportional_millionths: last_hop_fee_prop,
3048 cltv_expiry_delta: (8 << 4) | 1,
3049 htlc_minimum_msat: None,
3050 htlc_maximum_msat: last_hop_htlc_max,
3052 let payee = Payee::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3053 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3054 let scorer = test_utils::TestScorer::with_penalty(0);
3055 get_route(&source_node_id, &payee, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()), Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &test_utils::TestLogger::new(), &scorer)
3059 fn unannounced_path_test() {
3060 // We should be able to send a payment to a destination without any help of a routing graph
3061 // if we have a channel with a common counterparty that appears in the first and last hop
3063 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3065 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3066 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3067 assert_eq!(route.paths[0].len(), 2);
3069 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3070 assert_eq!(route.paths[0][0].short_channel_id, 42);
3071 assert_eq!(route.paths[0][0].fee_msat, 1001);
3072 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3073 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3074 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3076 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3077 assert_eq!(route.paths[0][1].short_channel_id, 8);
3078 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3079 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3080 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
3081 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3085 fn overflow_unannounced_path_test_liquidity_underflow() {
3086 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3087 // the last-hop had a fee which overflowed a u64, we'd panic.
3088 // This was due to us adding the first-hop from us unconditionally, causing us to think
3089 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3090 // In this test, we previously hit a subtraction underflow due to having less available
3091 // liquidity at the last hop than 0.
3092 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());
3096 fn overflow_unannounced_path_test_feerate_overflow() {
3097 // This tests for the same case as above, except instead of hitting a subtraction
3098 // underflow, we hit a case where the fee charged at a hop overflowed.
3099 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());
3103 fn available_amount_while_routing_test() {
3104 // Tests whether we choose the correct available channel amount while routing.
3106 let (secp_ctx, network_graph, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
3107 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3108 let scorer = test_utils::TestScorer::with_penalty(0);
3109 let payee = Payee::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3111 // We will use a simple single-path route from
3112 // our node to node2 via node0: channels {1, 3}.
3114 // First disable all other paths.
3115 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3116 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3117 short_channel_id: 2,
3120 cltv_expiry_delta: 0,
3121 htlc_minimum_msat: 0,
3122 htlc_maximum_msat: OptionalField::Present(100_000),
3124 fee_proportional_millionths: 0,
3125 excess_data: Vec::new()
3127 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3128 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3129 short_channel_id: 12,
3132 cltv_expiry_delta: 0,
3133 htlc_minimum_msat: 0,
3134 htlc_maximum_msat: OptionalField::Present(100_000),
3136 fee_proportional_millionths: 0,
3137 excess_data: Vec::new()
3140 // Make the first channel (#1) very permissive,
3141 // and we will be testing all limits on the second channel.
3142 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3143 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3144 short_channel_id: 1,
3147 cltv_expiry_delta: 0,
3148 htlc_minimum_msat: 0,
3149 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3151 fee_proportional_millionths: 0,
3152 excess_data: Vec::new()
3155 // First, let's see if routing works if we have absolutely no idea about the available amount.
3156 // In this case, it should be set to 250_000 sats.
3157 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3158 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3159 short_channel_id: 3,
3162 cltv_expiry_delta: 0,
3163 htlc_minimum_msat: 0,
3164 htlc_maximum_msat: OptionalField::Absent,
3166 fee_proportional_millionths: 0,
3167 excess_data: Vec::new()
3171 // Attempt to route more than available results in a failure.
3172 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3173 &our_id, &payee, &network_graph, None, 250_000_001, 42, Arc::clone(&logger), &scorer) {
3174 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3175 } else { panic!(); }
3179 // Now, attempt to route an exact amount we have should be fine.
3180 let route = get_route(&our_id, &payee, &network_graph, None, 250_000_000, 42, Arc::clone(&logger), &scorer).unwrap();
3181 assert_eq!(route.paths.len(), 1);
3182 let path = route.paths.last().unwrap();
3183 assert_eq!(path.len(), 2);
3184 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3185 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3188 // Check that setting outbound_capacity_msat in first_hops limits the channels.
3189 // Disable channel #1 and use another first hop.
3190 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3191 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3192 short_channel_id: 1,
3195 cltv_expiry_delta: 0,
3196 htlc_minimum_msat: 0,
3197 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3199 fee_proportional_millionths: 0,
3200 excess_data: Vec::new()
3203 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
3204 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3207 // Attempt to route more than available results in a failure.
3208 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3209 &our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, 42, Arc::clone(&logger), &scorer) {
3210 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3211 } else { panic!(); }
3215 // Now, attempt to route an exact amount we have should be fine.
3216 let route = get_route(&our_id, &payee, &network_graph, Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_000, 42, Arc::clone(&logger), &scorer).unwrap();
3217 assert_eq!(route.paths.len(), 1);
3218 let path = route.paths.last().unwrap();
3219 assert_eq!(path.len(), 2);
3220 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3221 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3224 // Enable channel #1 back.
3225 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3226 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3227 short_channel_id: 1,
3230 cltv_expiry_delta: 0,
3231 htlc_minimum_msat: 0,
3232 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3234 fee_proportional_millionths: 0,
3235 excess_data: Vec::new()
3239 // Now let's see if routing works if we know only htlc_maximum_msat.
3240 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3241 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3242 short_channel_id: 3,
3245 cltv_expiry_delta: 0,
3246 htlc_minimum_msat: 0,
3247 htlc_maximum_msat: OptionalField::Present(15_000),
3249 fee_proportional_millionths: 0,
3250 excess_data: Vec::new()
3254 // Attempt to route more than available results in a failure.
3255 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3256 &our_id, &payee, &network_graph, None, 15_001, 42, Arc::clone(&logger), &scorer) {
3257 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3258 } else { panic!(); }
3262 // Now, attempt to route an exact amount we have should be fine.
3263 let route = get_route(&our_id, &payee, &network_graph, None, 15_000, 42, Arc::clone(&logger), &scorer).unwrap();
3264 assert_eq!(route.paths.len(), 1);
3265 let path = route.paths.last().unwrap();
3266 assert_eq!(path.len(), 2);
3267 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3268 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3271 // Now let's see if routing works if we know only capacity from the UTXO.
3273 // We can't change UTXO capacity on the fly, so we'll disable
3274 // the existing channel and add another one with the capacity we need.
3275 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3276 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3277 short_channel_id: 3,
3280 cltv_expiry_delta: 0,
3281 htlc_minimum_msat: 0,
3282 htlc_maximum_msat: OptionalField::Absent,
3284 fee_proportional_millionths: 0,
3285 excess_data: Vec::new()
3288 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3289 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3290 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3291 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3292 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3294 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3295 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
3297 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3298 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3299 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3300 short_channel_id: 333,
3303 cltv_expiry_delta: (3 << 4) | 1,
3304 htlc_minimum_msat: 0,
3305 htlc_maximum_msat: OptionalField::Absent,
3307 fee_proportional_millionths: 0,
3308 excess_data: Vec::new()
3310 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3311 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3312 short_channel_id: 333,
3315 cltv_expiry_delta: (3 << 4) | 2,
3316 htlc_minimum_msat: 0,
3317 htlc_maximum_msat: OptionalField::Absent,
3319 fee_proportional_millionths: 0,
3320 excess_data: Vec::new()
3324 // Attempt to route more than available results in a failure.
3325 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3326 &our_id, &payee, &network_graph, None, 15_001, 42, Arc::clone(&logger), &scorer) {
3327 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3328 } else { panic!(); }
3332 // Now, attempt to route an exact amount we have should be fine.
3333 let route = get_route(&our_id, &payee, &network_graph, None, 15_000, 42, Arc::clone(&logger), &scorer).unwrap();
3334 assert_eq!(route.paths.len(), 1);
3335 let path = route.paths.last().unwrap();
3336 assert_eq!(path.len(), 2);
3337 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3338 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3341 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3342 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3343 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3344 short_channel_id: 333,
3347 cltv_expiry_delta: 0,
3348 htlc_minimum_msat: 0,
3349 htlc_maximum_msat: OptionalField::Present(10_000),
3351 fee_proportional_millionths: 0,
3352 excess_data: Vec::new()
3356 // Attempt to route more than available results in a failure.
3357 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3358 &our_id, &payee, &network_graph, None, 10_001, 42, Arc::clone(&logger), &scorer) {
3359 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3360 } else { panic!(); }
3364 // Now, attempt to route an exact amount we have should be fine.
3365 let route = get_route(&our_id, &payee, &network_graph, None, 10_000, 42, Arc::clone(&logger), &scorer).unwrap();
3366 assert_eq!(route.paths.len(), 1);
3367 let path = route.paths.last().unwrap();
3368 assert_eq!(path.len(), 2);
3369 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3370 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3375 fn available_liquidity_last_hop_test() {
3376 // Check that available liquidity properly limits the path even when only
3377 // one of the latter hops is limited.
3378 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3379 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3380 let scorer = test_utils::TestScorer::with_penalty(0);
3381 let payee = Payee::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3383 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3384 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3385 // Total capacity: 50 sats.
3387 // Disable other potential paths.
3388 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3389 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3390 short_channel_id: 2,
3393 cltv_expiry_delta: 0,
3394 htlc_minimum_msat: 0,
3395 htlc_maximum_msat: OptionalField::Present(100_000),
3397 fee_proportional_millionths: 0,
3398 excess_data: Vec::new()
3400 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3401 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3402 short_channel_id: 7,
3405 cltv_expiry_delta: 0,
3406 htlc_minimum_msat: 0,
3407 htlc_maximum_msat: OptionalField::Present(100_000),
3409 fee_proportional_millionths: 0,
3410 excess_data: Vec::new()
3415 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3416 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3417 short_channel_id: 12,
3420 cltv_expiry_delta: 0,
3421 htlc_minimum_msat: 0,
3422 htlc_maximum_msat: OptionalField::Present(100_000),
3424 fee_proportional_millionths: 0,
3425 excess_data: Vec::new()
3427 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3428 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3429 short_channel_id: 13,
3432 cltv_expiry_delta: 0,
3433 htlc_minimum_msat: 0,
3434 htlc_maximum_msat: OptionalField::Present(100_000),
3436 fee_proportional_millionths: 0,
3437 excess_data: Vec::new()
3440 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3441 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3442 short_channel_id: 6,
3445 cltv_expiry_delta: 0,
3446 htlc_minimum_msat: 0,
3447 htlc_maximum_msat: OptionalField::Present(50_000),
3449 fee_proportional_millionths: 0,
3450 excess_data: Vec::new()
3452 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3453 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3454 short_channel_id: 11,
3457 cltv_expiry_delta: 0,
3458 htlc_minimum_msat: 0,
3459 htlc_maximum_msat: OptionalField::Present(100_000),
3461 fee_proportional_millionths: 0,
3462 excess_data: Vec::new()
3465 // Attempt to route more than available results in a failure.
3466 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3467 &our_id, &payee, &network_graph, None, 60_000, 42, Arc::clone(&logger), &scorer) {
3468 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3469 } else { panic!(); }
3473 // Now, attempt to route 49 sats (just a bit below the capacity).
3474 let route = get_route(&our_id, &payee, &network_graph, None, 49_000, 42, Arc::clone(&logger), &scorer).unwrap();
3475 assert_eq!(route.paths.len(), 1);
3476 let mut total_amount_paid_msat = 0;
3477 for path in &route.paths {
3478 assert_eq!(path.len(), 4);
3479 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3480 total_amount_paid_msat += path.last().unwrap().fee_msat;
3482 assert_eq!(total_amount_paid_msat, 49_000);
3486 // Attempt to route an exact amount is also fine
3487 let route = get_route(&our_id, &payee, &network_graph, None, 50_000, 42, Arc::clone(&logger), &scorer).unwrap();
3488 assert_eq!(route.paths.len(), 1);
3489 let mut total_amount_paid_msat = 0;
3490 for path in &route.paths {
3491 assert_eq!(path.len(), 4);
3492 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3493 total_amount_paid_msat += path.last().unwrap().fee_msat;
3495 assert_eq!(total_amount_paid_msat, 50_000);
3500 fn ignore_fee_first_hop_test() {
3501 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3502 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3503 let scorer = test_utils::TestScorer::with_penalty(0);
3504 let payee = Payee::from_node_id(nodes[2]);
3506 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3507 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3508 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3509 short_channel_id: 1,
3512 cltv_expiry_delta: 0,
3513 htlc_minimum_msat: 0,
3514 htlc_maximum_msat: OptionalField::Present(100_000),
3515 fee_base_msat: 1_000_000,
3516 fee_proportional_millionths: 0,
3517 excess_data: Vec::new()
3519 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3520 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3521 short_channel_id: 3,
3524 cltv_expiry_delta: 0,
3525 htlc_minimum_msat: 0,
3526 htlc_maximum_msat: OptionalField::Present(50_000),
3528 fee_proportional_millionths: 0,
3529 excess_data: Vec::new()
3533 let route = get_route(&our_id, &payee, &network_graph, None, 50_000, 42, Arc::clone(&logger), &scorer).unwrap();
3534 assert_eq!(route.paths.len(), 1);
3535 let mut total_amount_paid_msat = 0;
3536 for path in &route.paths {
3537 assert_eq!(path.len(), 2);
3538 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3539 total_amount_paid_msat += path.last().unwrap().fee_msat;
3541 assert_eq!(total_amount_paid_msat, 50_000);
3546 fn simple_mpp_route_test() {
3547 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3548 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3549 let scorer = test_utils::TestScorer::with_penalty(0);
3550 let payee = Payee::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3552 // We need a route consisting of 3 paths:
3553 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3554 // To achieve this, the amount being transferred should be around
3555 // the total capacity of these 3 paths.
3557 // First, we set limits on these (previously unlimited) channels.
3558 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3560 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3561 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3562 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3563 short_channel_id: 1,
3566 cltv_expiry_delta: 0,
3567 htlc_minimum_msat: 0,
3568 htlc_maximum_msat: OptionalField::Present(100_000),
3570 fee_proportional_millionths: 0,
3571 excess_data: Vec::new()
3573 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3574 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3575 short_channel_id: 3,
3578 cltv_expiry_delta: 0,
3579 htlc_minimum_msat: 0,
3580 htlc_maximum_msat: OptionalField::Present(50_000),
3582 fee_proportional_millionths: 0,
3583 excess_data: Vec::new()
3586 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3587 // (total limit 60).
3588 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3589 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3590 short_channel_id: 12,
3593 cltv_expiry_delta: 0,
3594 htlc_minimum_msat: 0,
3595 htlc_maximum_msat: OptionalField::Present(60_000),
3597 fee_proportional_millionths: 0,
3598 excess_data: Vec::new()
3600 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3601 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3602 short_channel_id: 13,
3605 cltv_expiry_delta: 0,
3606 htlc_minimum_msat: 0,
3607 htlc_maximum_msat: OptionalField::Present(60_000),
3609 fee_proportional_millionths: 0,
3610 excess_data: Vec::new()
3613 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3614 // (total capacity 180 sats).
3615 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3616 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3617 short_channel_id: 2,
3620 cltv_expiry_delta: 0,
3621 htlc_minimum_msat: 0,
3622 htlc_maximum_msat: OptionalField::Present(200_000),
3624 fee_proportional_millionths: 0,
3625 excess_data: Vec::new()
3627 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3628 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3629 short_channel_id: 4,
3632 cltv_expiry_delta: 0,
3633 htlc_minimum_msat: 0,
3634 htlc_maximum_msat: OptionalField::Present(180_000),
3636 fee_proportional_millionths: 0,
3637 excess_data: Vec::new()
3641 // Attempt to route more than available results in a failure.
3642 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3643 &our_id, &payee, &network_graph, None, 300_000, 42, Arc::clone(&logger), &scorer) {
3644 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3645 } else { panic!(); }
3649 // Now, attempt to route 250 sats (just a bit below the capacity).
3650 // Our algorithm should provide us with these 3 paths.
3651 let route = get_route(&our_id, &payee, &network_graph, None, 250_000, 42, Arc::clone(&logger), &scorer).unwrap();
3652 assert_eq!(route.paths.len(), 3);
3653 let mut total_amount_paid_msat = 0;
3654 for path in &route.paths {
3655 assert_eq!(path.len(), 2);
3656 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3657 total_amount_paid_msat += path.last().unwrap().fee_msat;
3659 assert_eq!(total_amount_paid_msat, 250_000);
3663 // Attempt to route an exact amount is also fine
3664 let route = get_route(&our_id, &payee, &network_graph, None, 290_000, 42, Arc::clone(&logger), &scorer).unwrap();
3665 assert_eq!(route.paths.len(), 3);
3666 let mut total_amount_paid_msat = 0;
3667 for path in &route.paths {
3668 assert_eq!(path.len(), 2);
3669 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3670 total_amount_paid_msat += path.last().unwrap().fee_msat;
3672 assert_eq!(total_amount_paid_msat, 290_000);
3677 fn long_mpp_route_test() {
3678 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3679 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3680 let scorer = test_utils::TestScorer::with_penalty(0);
3681 let payee = Payee::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3683 // We need a route consisting of 3 paths:
3684 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3685 // Note that these paths overlap (channels 5, 12, 13).
3686 // We will route 300 sats.
3687 // Each path will have 100 sats capacity, those channels which
3688 // are used twice will have 200 sats capacity.
3690 // Disable other potential paths.
3691 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3692 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3693 short_channel_id: 2,
3696 cltv_expiry_delta: 0,
3697 htlc_minimum_msat: 0,
3698 htlc_maximum_msat: OptionalField::Present(100_000),
3700 fee_proportional_millionths: 0,
3701 excess_data: Vec::new()
3703 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3704 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3705 short_channel_id: 7,
3708 cltv_expiry_delta: 0,
3709 htlc_minimum_msat: 0,
3710 htlc_maximum_msat: OptionalField::Present(100_000),
3712 fee_proportional_millionths: 0,
3713 excess_data: Vec::new()
3716 // Path via {node0, node2} is channels {1, 3, 5}.
3717 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3718 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3719 short_channel_id: 1,
3722 cltv_expiry_delta: 0,
3723 htlc_minimum_msat: 0,
3724 htlc_maximum_msat: OptionalField::Present(100_000),
3726 fee_proportional_millionths: 0,
3727 excess_data: Vec::new()
3729 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3730 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3731 short_channel_id: 3,
3734 cltv_expiry_delta: 0,
3735 htlc_minimum_msat: 0,
3736 htlc_maximum_msat: OptionalField::Present(100_000),
3738 fee_proportional_millionths: 0,
3739 excess_data: Vec::new()
3742 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3743 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3744 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3745 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3746 short_channel_id: 5,
3749 cltv_expiry_delta: 0,
3750 htlc_minimum_msat: 0,
3751 htlc_maximum_msat: OptionalField::Present(200_000),
3753 fee_proportional_millionths: 0,
3754 excess_data: Vec::new()
3757 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3758 // Add 100 sats to the capacities of {12, 13}, because these channels
3759 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3760 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3761 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3762 short_channel_id: 12,
3765 cltv_expiry_delta: 0,
3766 htlc_minimum_msat: 0,
3767 htlc_maximum_msat: OptionalField::Present(200_000),
3769 fee_proportional_millionths: 0,
3770 excess_data: Vec::new()
3772 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3773 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3774 short_channel_id: 13,
3777 cltv_expiry_delta: 0,
3778 htlc_minimum_msat: 0,
3779 htlc_maximum_msat: OptionalField::Present(200_000),
3781 fee_proportional_millionths: 0,
3782 excess_data: Vec::new()
3785 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3786 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3787 short_channel_id: 6,
3790 cltv_expiry_delta: 0,
3791 htlc_minimum_msat: 0,
3792 htlc_maximum_msat: OptionalField::Present(100_000),
3794 fee_proportional_millionths: 0,
3795 excess_data: Vec::new()
3797 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3798 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3799 short_channel_id: 11,
3802 cltv_expiry_delta: 0,
3803 htlc_minimum_msat: 0,
3804 htlc_maximum_msat: OptionalField::Present(100_000),
3806 fee_proportional_millionths: 0,
3807 excess_data: Vec::new()
3810 // Path via {node7, node2} is channels {12, 13, 5}.
3811 // We already limited them to 200 sats (they are used twice for 100 sats).
3812 // Nothing to do here.
3815 // Attempt to route more than available results in a failure.
3816 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3817 &our_id, &payee, &network_graph, None, 350_000, 42, Arc::clone(&logger), &scorer) {
3818 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3819 } else { panic!(); }
3823 // Now, attempt to route 300 sats (exact amount we can route).
3824 // Our algorithm should provide us with these 3 paths, 100 sats each.
3825 let route = get_route(&our_id, &payee, &network_graph, None, 300_000, 42, Arc::clone(&logger), &scorer).unwrap();
3826 assert_eq!(route.paths.len(), 3);
3828 let mut total_amount_paid_msat = 0;
3829 for path in &route.paths {
3830 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3831 total_amount_paid_msat += path.last().unwrap().fee_msat;
3833 assert_eq!(total_amount_paid_msat, 300_000);
3839 fn mpp_cheaper_route_test() {
3840 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3841 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3842 let scorer = test_utils::TestScorer::with_penalty(0);
3843 let payee = Payee::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3845 // This test checks that if we have two cheaper paths and one more expensive path,
3846 // so that liquidity-wise any 2 of 3 combination is sufficient,
3847 // two cheaper paths will be taken.
3848 // These paths have equal available liquidity.
3850 // We need a combination of 3 paths:
3851 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3852 // Note that these paths overlap (channels 5, 12, 13).
3853 // Each path will have 100 sats capacity, those channels which
3854 // are used twice will have 200 sats capacity.
3856 // Disable other potential paths.
3857 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3858 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3859 short_channel_id: 2,
3862 cltv_expiry_delta: 0,
3863 htlc_minimum_msat: 0,
3864 htlc_maximum_msat: OptionalField::Present(100_000),
3866 fee_proportional_millionths: 0,
3867 excess_data: Vec::new()
3869 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3870 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3871 short_channel_id: 7,
3874 cltv_expiry_delta: 0,
3875 htlc_minimum_msat: 0,
3876 htlc_maximum_msat: OptionalField::Present(100_000),
3878 fee_proportional_millionths: 0,
3879 excess_data: Vec::new()
3882 // Path via {node0, node2} is channels {1, 3, 5}.
3883 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3884 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3885 short_channel_id: 1,
3888 cltv_expiry_delta: 0,
3889 htlc_minimum_msat: 0,
3890 htlc_maximum_msat: OptionalField::Present(100_000),
3892 fee_proportional_millionths: 0,
3893 excess_data: Vec::new()
3895 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3896 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3897 short_channel_id: 3,
3900 cltv_expiry_delta: 0,
3901 htlc_minimum_msat: 0,
3902 htlc_maximum_msat: OptionalField::Present(100_000),
3904 fee_proportional_millionths: 0,
3905 excess_data: Vec::new()
3908 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3909 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3910 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3911 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3912 short_channel_id: 5,
3915 cltv_expiry_delta: 0,
3916 htlc_minimum_msat: 0,
3917 htlc_maximum_msat: OptionalField::Present(200_000),
3919 fee_proportional_millionths: 0,
3920 excess_data: Vec::new()
3923 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3924 // Add 100 sats to the capacities of {12, 13}, because these channels
3925 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3926 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3927 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3928 short_channel_id: 12,
3931 cltv_expiry_delta: 0,
3932 htlc_minimum_msat: 0,
3933 htlc_maximum_msat: OptionalField::Present(200_000),
3935 fee_proportional_millionths: 0,
3936 excess_data: Vec::new()
3938 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3939 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3940 short_channel_id: 13,
3943 cltv_expiry_delta: 0,
3944 htlc_minimum_msat: 0,
3945 htlc_maximum_msat: OptionalField::Present(200_000),
3947 fee_proportional_millionths: 0,
3948 excess_data: Vec::new()
3951 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3952 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3953 short_channel_id: 6,
3956 cltv_expiry_delta: 0,
3957 htlc_minimum_msat: 0,
3958 htlc_maximum_msat: OptionalField::Present(100_000),
3959 fee_base_msat: 1_000,
3960 fee_proportional_millionths: 0,
3961 excess_data: Vec::new()
3963 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3964 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3965 short_channel_id: 11,
3968 cltv_expiry_delta: 0,
3969 htlc_minimum_msat: 0,
3970 htlc_maximum_msat: OptionalField::Present(100_000),
3972 fee_proportional_millionths: 0,
3973 excess_data: Vec::new()
3976 // Path via {node7, node2} is channels {12, 13, 5}.
3977 // We already limited them to 200 sats (they are used twice for 100 sats).
3978 // Nothing to do here.
3981 // Now, attempt to route 180 sats.
3982 // Our algorithm should provide us with these 2 paths.
3983 let route = get_route(&our_id, &payee, &network_graph, None, 180_000, 42, Arc::clone(&logger), &scorer).unwrap();
3984 assert_eq!(route.paths.len(), 2);
3986 let mut total_value_transferred_msat = 0;
3987 let mut total_paid_msat = 0;
3988 for path in &route.paths {
3989 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3990 total_value_transferred_msat += path.last().unwrap().fee_msat;
3992 total_paid_msat += hop.fee_msat;
3995 // If we paid fee, this would be higher.
3996 assert_eq!(total_value_transferred_msat, 180_000);
3997 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
3998 assert_eq!(total_fees_paid, 0);
4003 fn fees_on_mpp_route_test() {
4004 // This test makes sure that MPP algorithm properly takes into account
4005 // fees charged on the channels, by making the fees impactful:
4006 // if the fee is not properly accounted for, the behavior is different.
4007 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4008 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4009 let scorer = test_utils::TestScorer::with_penalty(0);
4010 let payee = Payee::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4012 // We need a route consisting of 2 paths:
4013 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4014 // We will route 200 sats, Each path will have 100 sats capacity.
4016 // This test is not particularly stable: e.g.,
4017 // there's a way to route via {node0, node2, node4}.
4018 // It works while pathfinding is deterministic, but can be broken otherwise.
4019 // It's fine to ignore this concern for now.
4021 // Disable other potential paths.
4022 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4023 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4024 short_channel_id: 2,
4027 cltv_expiry_delta: 0,
4028 htlc_minimum_msat: 0,
4029 htlc_maximum_msat: OptionalField::Present(100_000),
4031 fee_proportional_millionths: 0,
4032 excess_data: Vec::new()
4035 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4036 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4037 short_channel_id: 7,
4040 cltv_expiry_delta: 0,
4041 htlc_minimum_msat: 0,
4042 htlc_maximum_msat: OptionalField::Present(100_000),
4044 fee_proportional_millionths: 0,
4045 excess_data: Vec::new()
4048 // Path via {node0, node2} is channels {1, 3, 5}.
4049 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4050 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4051 short_channel_id: 1,
4054 cltv_expiry_delta: 0,
4055 htlc_minimum_msat: 0,
4056 htlc_maximum_msat: OptionalField::Present(100_000),
4058 fee_proportional_millionths: 0,
4059 excess_data: Vec::new()
4061 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4062 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4063 short_channel_id: 3,
4066 cltv_expiry_delta: 0,
4067 htlc_minimum_msat: 0,
4068 htlc_maximum_msat: OptionalField::Present(100_000),
4070 fee_proportional_millionths: 0,
4071 excess_data: Vec::new()
4074 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4075 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4076 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4077 short_channel_id: 5,
4080 cltv_expiry_delta: 0,
4081 htlc_minimum_msat: 0,
4082 htlc_maximum_msat: OptionalField::Present(100_000),
4084 fee_proportional_millionths: 0,
4085 excess_data: Vec::new()
4088 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4089 // All channels should be 100 sats capacity. But for the fee experiment,
4090 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4091 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4092 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4093 // so no matter how large are other channels,
4094 // the whole path will be limited by 100 sats with just these 2 conditions:
4095 // - channel 12 capacity is 250 sats
4096 // - fee for channel 6 is 150 sats
4097 // Let's test this by enforcing these 2 conditions and removing other limits.
4098 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4099 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4100 short_channel_id: 12,
4103 cltv_expiry_delta: 0,
4104 htlc_minimum_msat: 0,
4105 htlc_maximum_msat: OptionalField::Present(250_000),
4107 fee_proportional_millionths: 0,
4108 excess_data: Vec::new()
4110 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4111 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4112 short_channel_id: 13,
4115 cltv_expiry_delta: 0,
4116 htlc_minimum_msat: 0,
4117 htlc_maximum_msat: OptionalField::Absent,
4119 fee_proportional_millionths: 0,
4120 excess_data: Vec::new()
4123 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4124 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4125 short_channel_id: 6,
4128 cltv_expiry_delta: 0,
4129 htlc_minimum_msat: 0,
4130 htlc_maximum_msat: OptionalField::Absent,
4131 fee_base_msat: 150_000,
4132 fee_proportional_millionths: 0,
4133 excess_data: Vec::new()
4135 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4136 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4137 short_channel_id: 11,
4140 cltv_expiry_delta: 0,
4141 htlc_minimum_msat: 0,
4142 htlc_maximum_msat: OptionalField::Absent,
4144 fee_proportional_millionths: 0,
4145 excess_data: Vec::new()
4149 // Attempt to route more than available results in a failure.
4150 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4151 &our_id, &payee, &network_graph, None, 210_000, 42, Arc::clone(&logger), &scorer) {
4152 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4153 } else { panic!(); }
4157 // Now, attempt to route 200 sats (exact amount we can route).
4158 let route = get_route(&our_id, &payee, &network_graph, None, 200_000, 42, Arc::clone(&logger), &scorer).unwrap();
4159 assert_eq!(route.paths.len(), 2);
4161 let mut total_amount_paid_msat = 0;
4162 for path in &route.paths {
4163 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4164 total_amount_paid_msat += path.last().unwrap().fee_msat;
4166 assert_eq!(total_amount_paid_msat, 200_000);
4167 assert_eq!(route.get_total_fees(), 150_000);
4172 fn mpp_with_last_hops() {
4173 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4174 // via a single last-hop route hint, we'd fail to route if we first collected routes
4175 // totaling close but not quite enough to fund the full payment.
4177 // This was because we considered last-hop hints to have exactly the sought payment amount
4178 // instead of the amount we were trying to collect, needlessly limiting our path searching
4179 // at the very first hop.
4181 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4182 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4183 // to only have the remaining to-collect amount in available liquidity.
4185 // This bug appeared in production in some specific channel configurations.
4186 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4187 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4188 let scorer = test_utils::TestScorer::with_penalty(0);
4189 let payee = Payee::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4190 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4191 src_node_id: nodes[2],
4192 short_channel_id: 42,
4193 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4194 cltv_expiry_delta: 42,
4195 htlc_minimum_msat: None,
4196 htlc_maximum_msat: None,
4199 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4200 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4201 // would first use the no-fee route and then fail to find a path along the second route as
4202 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4203 // under 5% of our payment amount.
4204 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4205 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4206 short_channel_id: 1,
4209 cltv_expiry_delta: (5 << 4) | 5,
4210 htlc_minimum_msat: 0,
4211 htlc_maximum_msat: OptionalField::Present(99_000),
4212 fee_base_msat: u32::max_value(),
4213 fee_proportional_millionths: u32::max_value(),
4214 excess_data: Vec::new()
4216 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4217 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4218 short_channel_id: 2,
4221 cltv_expiry_delta: (5 << 4) | 3,
4222 htlc_minimum_msat: 0,
4223 htlc_maximum_msat: OptionalField::Present(99_000),
4224 fee_base_msat: u32::max_value(),
4225 fee_proportional_millionths: u32::max_value(),
4226 excess_data: Vec::new()
4228 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4229 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4230 short_channel_id: 4,
4233 cltv_expiry_delta: (4 << 4) | 1,
4234 htlc_minimum_msat: 0,
4235 htlc_maximum_msat: OptionalField::Absent,
4237 fee_proportional_millionths: 0,
4238 excess_data: Vec::new()
4240 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4241 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4242 short_channel_id: 13,
4244 flags: 0|2, // Channel disabled
4245 cltv_expiry_delta: (13 << 4) | 1,
4246 htlc_minimum_msat: 0,
4247 htlc_maximum_msat: OptionalField::Absent,
4249 fee_proportional_millionths: 2000000,
4250 excess_data: Vec::new()
4253 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4255 let route = get_route(&our_id, &payee, &network_graph, None, 100_000, 42, Arc::clone(&logger), &scorer).unwrap();
4256 assert_eq!(route.paths.len(), 2);
4257 // Paths are somewhat randomly ordered, but:
4258 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4259 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4260 assert_eq!(route.paths[0][0].short_channel_id, 2);
4261 assert_eq!(route.paths[0][0].fee_msat, 1);
4262 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4263 assert_eq!(route.paths[1][0].short_channel_id, 1);
4264 assert_eq!(route.paths[1][0].fee_msat, 0);
4265 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4266 assert_eq!(route.get_total_fees(), 1);
4267 assert_eq!(route.get_total_amount(), 100_000);
4271 fn drop_lowest_channel_mpp_route_test() {
4272 // This test checks that low-capacity channel is dropped when after
4273 // path finding we realize that we found more capacity than we need.
4274 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4275 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4276 let scorer = test_utils::TestScorer::with_penalty(0);
4277 let payee = Payee::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4279 // We need a route consisting of 3 paths:
4280 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4282 // The first and the second paths should be sufficient, but the third should be
4283 // cheaper, so that we select it but drop later.
4285 // First, we set limits on these (previously unlimited) channels.
4286 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4288 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4289 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4290 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4291 short_channel_id: 1,
4294 cltv_expiry_delta: 0,
4295 htlc_minimum_msat: 0,
4296 htlc_maximum_msat: OptionalField::Present(100_000),
4298 fee_proportional_millionths: 0,
4299 excess_data: Vec::new()
4301 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4302 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4303 short_channel_id: 3,
4306 cltv_expiry_delta: 0,
4307 htlc_minimum_msat: 0,
4308 htlc_maximum_msat: OptionalField::Present(50_000),
4310 fee_proportional_millionths: 0,
4311 excess_data: Vec::new()
4314 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4315 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4316 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4317 short_channel_id: 12,
4320 cltv_expiry_delta: 0,
4321 htlc_minimum_msat: 0,
4322 htlc_maximum_msat: OptionalField::Present(60_000),
4324 fee_proportional_millionths: 0,
4325 excess_data: Vec::new()
4327 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4328 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4329 short_channel_id: 13,
4332 cltv_expiry_delta: 0,
4333 htlc_minimum_msat: 0,
4334 htlc_maximum_msat: OptionalField::Present(60_000),
4336 fee_proportional_millionths: 0,
4337 excess_data: Vec::new()
4340 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4341 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4342 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4343 short_channel_id: 2,
4346 cltv_expiry_delta: 0,
4347 htlc_minimum_msat: 0,
4348 htlc_maximum_msat: OptionalField::Present(20_000),
4350 fee_proportional_millionths: 0,
4351 excess_data: Vec::new()
4353 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4354 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4355 short_channel_id: 4,
4358 cltv_expiry_delta: 0,
4359 htlc_minimum_msat: 0,
4360 htlc_maximum_msat: OptionalField::Present(20_000),
4362 fee_proportional_millionths: 0,
4363 excess_data: Vec::new()
4367 // Attempt to route more than available results in a failure.
4368 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4369 &our_id, &payee, &network_graph, None, 150_000, 42, Arc::clone(&logger), &scorer) {
4370 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4371 } else { panic!(); }
4375 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4376 // Our algorithm should provide us with these 3 paths.
4377 let route = get_route(&our_id, &payee, &network_graph, None, 125_000, 42, Arc::clone(&logger), &scorer).unwrap();
4378 assert_eq!(route.paths.len(), 3);
4379 let mut total_amount_paid_msat = 0;
4380 for path in &route.paths {
4381 assert_eq!(path.len(), 2);
4382 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4383 total_amount_paid_msat += path.last().unwrap().fee_msat;
4385 assert_eq!(total_amount_paid_msat, 125_000);
4389 // Attempt to route without the last small cheap channel
4390 let route = get_route(&our_id, &payee, &network_graph, None, 90_000, 42, Arc::clone(&logger), &scorer).unwrap();
4391 assert_eq!(route.paths.len(), 2);
4392 let mut total_amount_paid_msat = 0;
4393 for path in &route.paths {
4394 assert_eq!(path.len(), 2);
4395 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4396 total_amount_paid_msat += path.last().unwrap().fee_msat;
4398 assert_eq!(total_amount_paid_msat, 90_000);
4403 fn min_criteria_consistency() {
4404 // Test that we don't use an inconsistent metric between updating and walking nodes during
4405 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4406 // was updated with a different criterion from the heap sorting, resulting in loops in
4407 // calculated paths. We test for that specific case here.
4409 // We construct a network that looks like this:
4411 // node2 -1(3)2- node3
4415 // node1 -1(5)2- node4 -1(1)2- node6
4421 // We create a loop on the side of our real path - our destination is node 6, with a
4422 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4423 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4424 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4425 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4426 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4427 // "previous hop" being set to node 3, creating a loop in the path.
4428 let secp_ctx = Secp256k1::new();
4429 let logger = Arc::new(test_utils::TestLogger::new());
4430 let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
4431 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
4432 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4433 let scorer = test_utils::TestScorer::with_penalty(0);
4434 let payee = Payee::from_node_id(nodes[6]);
4436 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4437 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4438 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4439 short_channel_id: 6,
4442 cltv_expiry_delta: (6 << 4) | 0,
4443 htlc_minimum_msat: 0,
4444 htlc_maximum_msat: OptionalField::Absent,
4446 fee_proportional_millionths: 0,
4447 excess_data: Vec::new()
4449 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4451 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4452 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4453 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4454 short_channel_id: 5,
4457 cltv_expiry_delta: (5 << 4) | 0,
4458 htlc_minimum_msat: 0,
4459 htlc_maximum_msat: OptionalField::Absent,
4461 fee_proportional_millionths: 0,
4462 excess_data: Vec::new()
4464 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4466 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4467 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4468 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4469 short_channel_id: 4,
4472 cltv_expiry_delta: (4 << 4) | 0,
4473 htlc_minimum_msat: 0,
4474 htlc_maximum_msat: OptionalField::Absent,
4476 fee_proportional_millionths: 0,
4477 excess_data: Vec::new()
4479 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4481 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4482 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4483 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4484 short_channel_id: 3,
4487 cltv_expiry_delta: (3 << 4) | 0,
4488 htlc_minimum_msat: 0,
4489 htlc_maximum_msat: OptionalField::Absent,
4491 fee_proportional_millionths: 0,
4492 excess_data: Vec::new()
4494 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4496 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4497 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4498 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4499 short_channel_id: 2,
4502 cltv_expiry_delta: (2 << 4) | 0,
4503 htlc_minimum_msat: 0,
4504 htlc_maximum_msat: OptionalField::Absent,
4506 fee_proportional_millionths: 0,
4507 excess_data: Vec::new()
4510 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4511 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4512 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4513 short_channel_id: 1,
4516 cltv_expiry_delta: (1 << 4) | 0,
4517 htlc_minimum_msat: 100,
4518 htlc_maximum_msat: OptionalField::Absent,
4520 fee_proportional_millionths: 0,
4521 excess_data: Vec::new()
4523 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4526 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4527 let route = get_route(&our_id, &payee, &network_graph, None, 10_000, 42, Arc::clone(&logger), &scorer).unwrap();
4528 assert_eq!(route.paths.len(), 1);
4529 assert_eq!(route.paths[0].len(), 3);
4531 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4532 assert_eq!(route.paths[0][0].short_channel_id, 6);
4533 assert_eq!(route.paths[0][0].fee_msat, 100);
4534 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
4535 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4536 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4538 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4539 assert_eq!(route.paths[0][1].short_channel_id, 5);
4540 assert_eq!(route.paths[0][1].fee_msat, 0);
4541 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
4542 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4543 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4545 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4546 assert_eq!(route.paths[0][2].short_channel_id, 1);
4547 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4548 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4549 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4550 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4556 fn exact_fee_liquidity_limit() {
4557 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4558 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4559 // we calculated fees on a higher value, resulting in us ignoring such paths.
4560 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4561 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4562 let scorer = test_utils::TestScorer::with_penalty(0);
4563 let payee = Payee::from_node_id(nodes[2]);
4565 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4567 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4568 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4569 short_channel_id: 2,
4572 cltv_expiry_delta: 0,
4573 htlc_minimum_msat: 0,
4574 htlc_maximum_msat: OptionalField::Present(85_000),
4576 fee_proportional_millionths: 0,
4577 excess_data: Vec::new()
4580 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4581 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4582 short_channel_id: 12,
4585 cltv_expiry_delta: (4 << 4) | 1,
4586 htlc_minimum_msat: 0,
4587 htlc_maximum_msat: OptionalField::Present(270_000),
4589 fee_proportional_millionths: 1000000,
4590 excess_data: Vec::new()
4594 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4595 // 200% fee charged channel 13 in the 1-to-2 direction.
4596 let route = get_route(&our_id, &payee, &network_graph, None, 90_000, 42, Arc::clone(&logger), &scorer).unwrap();
4597 assert_eq!(route.paths.len(), 1);
4598 assert_eq!(route.paths[0].len(), 2);
4600 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4601 assert_eq!(route.paths[0][0].short_channel_id, 12);
4602 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4603 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4604 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4605 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4607 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4608 assert_eq!(route.paths[0][1].short_channel_id, 13);
4609 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4610 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4611 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4612 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4617 fn htlc_max_reduction_below_min() {
4618 // Test that if, while walking the graph, we reduce the value being sent to meet an
4619 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4620 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4621 // resulting in us thinking there is no possible path, even if other paths exist.
4622 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4623 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4624 let scorer = test_utils::TestScorer::with_penalty(0);
4625 let payee = Payee::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4627 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4628 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4629 // then try to send 90_000.
4630 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4631 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4632 short_channel_id: 2,
4635 cltv_expiry_delta: 0,
4636 htlc_minimum_msat: 0,
4637 htlc_maximum_msat: OptionalField::Present(80_000),
4639 fee_proportional_millionths: 0,
4640 excess_data: Vec::new()
4642 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4643 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4644 short_channel_id: 4,
4647 cltv_expiry_delta: (4 << 4) | 1,
4648 htlc_minimum_msat: 90_000,
4649 htlc_maximum_msat: OptionalField::Absent,
4651 fee_proportional_millionths: 0,
4652 excess_data: Vec::new()
4656 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
4657 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
4658 // expensive) channels 12-13 path.
4659 let route = get_route(&our_id, &payee, &network_graph, None, 90_000, 42, Arc::clone(&logger), &scorer).unwrap();
4660 assert_eq!(route.paths.len(), 1);
4661 assert_eq!(route.paths[0].len(), 2);
4663 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4664 assert_eq!(route.paths[0][0].short_channel_id, 12);
4665 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4666 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4667 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4668 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4670 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4671 assert_eq!(route.paths[0][1].short_channel_id, 13);
4672 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4673 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4674 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
4675 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4680 fn multiple_direct_first_hops() {
4681 // Previously we'd only ever considered one first hop path per counterparty.
4682 // However, as we don't restrict users to one channel per peer, we really need to support
4683 // looking at all first hop paths.
4684 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
4685 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
4686 // route over multiple channels with the same first hop.
4687 let secp_ctx = Secp256k1::new();
4688 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4689 let logger = Arc::new(test_utils::TestLogger::new());
4690 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
4691 let scorer = test_utils::TestScorer::with_penalty(0);
4692 let payee = Payee::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
4695 let route = get_route(&our_id, &payee, &network_graph, Some(&[
4696 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
4697 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
4698 ]), 100_000, 42, Arc::clone(&logger), &scorer).unwrap();
4699 assert_eq!(route.paths.len(), 1);
4700 assert_eq!(route.paths[0].len(), 1);
4702 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4703 assert_eq!(route.paths[0][0].short_channel_id, 3);
4704 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4707 let route = get_route(&our_id, &payee, &network_graph, Some(&[
4708 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4709 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4710 ]), 100_000, 42, Arc::clone(&logger), &scorer).unwrap();
4711 assert_eq!(route.paths.len(), 2);
4712 assert_eq!(route.paths[0].len(), 1);
4713 assert_eq!(route.paths[1].len(), 1);
4715 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4716 assert_eq!(route.paths[0][0].short_channel_id, 3);
4717 assert_eq!(route.paths[0][0].fee_msat, 50_000);
4719 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
4720 assert_eq!(route.paths[1][0].short_channel_id, 2);
4721 assert_eq!(route.paths[1][0].fee_msat, 50_000);
4726 fn prefers_shorter_route_with_higher_fees() {
4727 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4728 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4729 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
4732 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4733 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4734 short_channel_id: 2,
4737 cltv_expiry_delta: (5 << 4) | 3,
4738 htlc_minimum_msat: 0,
4739 htlc_maximum_msat: OptionalField::Absent,
4741 fee_proportional_millionths: u32::max_value(),
4742 excess_data: Vec::new()
4746 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
4747 let scorer = test_utils::TestScorer::with_penalty(0);
4748 let route = get_route(
4749 &our_id, &payee, &network_graph, None, 100, 42,
4750 Arc::clone(&logger), &scorer
4752 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4754 assert_eq!(route.get_total_fees(), 100);
4755 assert_eq!(route.get_total_amount(), 100);
4756 assert_eq!(path, vec![2, 4, 6, 11, 8]);
4758 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
4759 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
4760 let scorer = test_utils::TestScorer::with_penalty(100);
4761 let route = get_route(
4762 &our_id, &payee, &network_graph, None, 100, 42,
4763 Arc::clone(&logger), &scorer
4765 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4767 assert_eq!(route.get_total_fees(), 300);
4768 assert_eq!(route.get_total_amount(), 100);
4769 assert_eq!(path, vec![2, 4, 7, 10]);
4772 struct BadChannelScorer {
4773 short_channel_id: u64,
4777 impl Writeable for BadChannelScorer {
4778 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
4780 impl Score for BadChannelScorer {
4781 fn channel_cost(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUseParameters) -> u64 {
4782 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
4785 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
4786 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
4789 struct BadNodeScorer {
4794 impl Writeable for BadNodeScorer {
4795 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
4798 impl Score for BadNodeScorer {
4799 fn channel_cost(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUseParameters) -> u64 {
4800 if *target == self.node_id { u64::max_value() } else { 0 }
4803 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
4804 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
4808 fn avoids_routing_through_bad_channels_and_nodes() {
4809 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4810 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4811 let payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
4813 // A path to nodes[6] exists when no penalties are applied to any channel.
4814 let scorer = test_utils::TestScorer::with_penalty(0);
4815 let route = get_route(
4816 &our_id, &payee, &network_graph, None, 100, 42,
4817 Arc::clone(&logger), &scorer
4819 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4821 assert_eq!(route.get_total_fees(), 100);
4822 assert_eq!(route.get_total_amount(), 100);
4823 assert_eq!(path, vec![2, 4, 6, 11, 8]);
4825 // A different path to nodes[6] exists if channel 6 cannot be routed over.
4826 let scorer = BadChannelScorer { short_channel_id: 6 };
4827 let route = get_route(
4828 &our_id, &payee, &network_graph, None, 100, 42,
4829 Arc::clone(&logger), &scorer
4831 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4833 assert_eq!(route.get_total_fees(), 300);
4834 assert_eq!(route.get_total_amount(), 100);
4835 assert_eq!(path, vec![2, 4, 7, 10]);
4837 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
4838 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
4840 &our_id, &payee, &network_graph, None, 100, 42,
4841 Arc::clone(&logger), &scorer
4843 Err(LightningError { err, .. } ) => {
4844 assert_eq!(err, "Failed to find a path to the given destination");
4846 Ok(_) => panic!("Expected error"),
4851 fn total_fees_single_path() {
4855 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4856 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4857 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4860 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4861 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4862 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4865 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
4866 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4867 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
4873 assert_eq!(route.get_total_fees(), 250);
4874 assert_eq!(route.get_total_amount(), 225);
4878 fn total_fees_multi_path() {
4882 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4883 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4884 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4887 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4888 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4889 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4893 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
4894 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4895 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
4898 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
4899 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
4900 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
4906 assert_eq!(route.get_total_fees(), 200);
4907 assert_eq!(route.get_total_amount(), 300);
4911 fn total_empty_route_no_panic() {
4912 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
4913 // would both panic if the route was completely empty. We test to ensure they return 0
4914 // here, even though its somewhat nonsensical as a route.
4915 let route = Route { paths: Vec::new(), payee: None };
4917 assert_eq!(route.get_total_fees(), 0);
4918 assert_eq!(route.get_total_amount(), 0);
4922 fn limits_total_cltv_delta() {
4923 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4924 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4926 let scorer = test_utils::TestScorer::with_penalty(0);
4928 // Make sure that generally there is at least one route available
4929 let feasible_max_total_cltv_delta = 1008;
4930 let feasible_payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
4931 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
4932 let route = get_route(&our_id, &feasible_payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer).unwrap();
4933 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4934 assert_ne!(path.len(), 0);
4936 // But not if we exclude all paths on the basis of their accumulated CLTV delta
4937 let fail_max_total_cltv_delta = 23;
4938 let fail_payee = Payee::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
4939 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
4940 match get_route(&our_id, &fail_payee, &network_graph, None, 100, 42, Arc::clone(&logger), &scorer)
4942 Err(LightningError { err, .. } ) => {
4943 assert_eq!(err, "Failed to find a path to the given destination");
4945 Ok(_) => panic!("Expected error"),
4949 #[cfg(not(feature = "no-std"))]
4950 pub(super) fn random_init_seed() -> u64 {
4951 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
4952 use core::hash::{BuildHasher, Hasher};
4953 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
4954 println!("Using seed of {}", seed);
4957 #[cfg(not(feature = "no-std"))]
4958 use util::ser::Readable;
4961 #[cfg(not(feature = "no-std"))]
4962 fn generate_routes() {
4963 let mut d = match super::test_utils::get_route_file() {
4970 let graph = NetworkGraph::read(&mut d).unwrap();
4972 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
4973 let mut seed = random_init_seed() as usize;
4974 let nodes = graph.read_only().nodes().clone();
4975 'load_endpoints: for _ in 0..10 {
4977 seed = seed.overflowing_mul(0xdeadbeef).0;
4978 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
4979 seed = seed.overflowing_mul(0xdeadbeef).0;
4980 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
4981 let payee = Payee::from_node_id(dst);
4982 let amt = seed as u64 % 200_000_000;
4983 let params = ProbabilisticScoringParameters::default();
4984 let scorer = ProbabilisticScorer::new(params, &src, &graph);
4985 if get_route(src, &payee, &graph, None, amt, 42, &test_utils::TestLogger::new(), &scorer).is_ok() {
4986 continue 'load_endpoints;
4993 #[cfg(not(feature = "no-std"))]
4994 fn generate_routes_mpp() {
4995 let mut d = match super::test_utils::get_route_file() {
5002 let graph = NetworkGraph::read(&mut d).unwrap();
5004 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5005 let mut seed = random_init_seed() as usize;
5006 let nodes = graph.read_only().nodes().clone();
5007 'load_endpoints: for _ in 0..10 {
5009 seed = seed.overflowing_mul(0xdeadbeef).0;
5010 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5011 seed = seed.overflowing_mul(0xdeadbeef).0;
5012 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5013 let payee = Payee::from_node_id(dst).with_features(InvoiceFeatures::known());
5014 let amt = seed as u64 % 200_000_000;
5015 let params = ProbabilisticScoringParameters::default();
5016 let scorer = ProbabilisticScorer::new(params, &src, &graph);
5017 if get_route(src, &payee, &graph, None, amt, 42, &test_utils::TestLogger::new(), &scorer).is_ok() {
5018 continue 'load_endpoints;
5025 #[cfg(all(test, not(feature = "no-std")))]
5026 pub(crate) mod test_utils {
5028 /// Tries to open a network graph file, or panics with a URL to fetch it.
5029 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5030 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5031 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5032 .or_else(|_| { // Fall back to guessing based on the binary location
5033 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5034 let mut path = std::env::current_exe().unwrap();
5035 path.pop(); // lightning-...
5037 path.pop(); // debug
5038 path.pop(); // target
5039 path.push("lightning");
5040 path.push("net_graph-2021-05-31.bin");
5041 eprintln!("{}", path.to_str().unwrap());
5044 .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");
5045 #[cfg(require_route_graph_test)]
5046 return Ok(res.unwrap());
5047 #[cfg(not(require_route_graph_test))]
5052 #[cfg(all(test, feature = "unstable", not(feature = "no-std")))]
5055 use bitcoin::hashes::Hash;
5056 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5057 use chain::transaction::OutPoint;
5058 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5059 use ln::features::{InitFeatures, InvoiceFeatures};
5060 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters, Scorer};
5061 use util::logger::{Logger, Record};
5065 struct DummyLogger {}
5066 impl Logger for DummyLogger {
5067 fn log(&self, _record: &Record) {}
5070 fn read_network_graph() -> NetworkGraph {
5071 let mut d = test_utils::get_route_file().unwrap();
5072 NetworkGraph::read(&mut d).unwrap()
5075 fn payer_pubkey() -> PublicKey {
5076 let secp_ctx = Secp256k1::new();
5077 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5081 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5083 channel_id: [0; 32],
5084 counterparty: ChannelCounterparty {
5085 features: InitFeatures::known(),
5087 unspendable_punishment_reserve: 0,
5088 forwarding_info: None,
5090 funding_txo: Some(OutPoint {
5091 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5093 short_channel_id: Some(1),
5094 channel_value_satoshis: 10_000_000,
5096 balance_msat: 10_000_000,
5097 outbound_capacity_msat: 10_000_000,
5098 inbound_capacity_msat: 0,
5099 unspendable_punishment_reserve: None,
5100 confirmations_required: None,
5101 force_close_spend_delay: None,
5103 is_funding_locked: true,
5110 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5111 let network_graph = read_network_graph();
5112 let scorer = FixedPenaltyScorer::with_penalty(0);
5113 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5117 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5118 let network_graph = read_network_graph();
5119 let scorer = FixedPenaltyScorer::with_penalty(0);
5120 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5124 fn generate_routes_with_default_scorer(bench: &mut Bencher) {
5125 let network_graph = read_network_graph();
5126 let scorer = Scorer::default();
5127 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5131 fn generate_mpp_routes_with_default_scorer(bench: &mut Bencher) {
5132 let network_graph = read_network_graph();
5133 let scorer = Scorer::default();
5134 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5138 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5139 let network_graph = read_network_graph();
5140 let params = ProbabilisticScoringParameters::default();
5141 let scorer = ProbabilisticScorer::new(params, &payer_pubkey(), &network_graph);
5142 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5146 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5147 let network_graph = read_network_graph();
5148 let params = ProbabilisticScoringParameters::default();
5149 let scorer = ProbabilisticScorer::new(params, &payer_pubkey(), &network_graph);
5150 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5153 fn generate_routes<S: Score>(
5154 bench: &mut Bencher, graph: &NetworkGraph, mut scorer: S, features: InvoiceFeatures
5156 let nodes = graph.read_only().nodes().clone();
5157 let payer = payer_pubkey();
5159 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5160 let mut routes = Vec::new();
5161 let mut route_endpoints = Vec::new();
5162 let mut seed: usize = 0xdeadbeef;
5163 'load_endpoints: for _ in 0..100 {
5166 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5168 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5169 let payee = Payee::from_node_id(dst).with_features(features.clone());
5170 let first_hop = first_hop(src);
5171 let amt = seed as u64 % 1_000_000;
5172 if let Ok(route) = get_route(&payer, &payee, &graph, Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer) {
5174 route_endpoints.push((first_hop, payee, amt));
5175 continue 'load_endpoints;
5180 // ...and seed the scorer with success and failure data...
5181 for route in routes {
5182 let amount = route.get_total_amount();
5183 if amount < 250_000 {
5184 for path in route.paths {
5185 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5187 } else if amount > 750_000 {
5188 for path in route.paths {
5189 let short_channel_id = path[path.len() / 2].short_channel_id;
5190 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5195 // ...then benchmark finding paths between the nodes we learned.
5198 let (first_hop, payee, amt) = &route_endpoints[idx % route_endpoints.len()];
5199 assert!(get_route(&payer, payee, &graph, Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer).is_ok());