1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! The top-level routing/network map tracking logic lives here.
12 //! You probably want to create a NetGraphMsgHandler and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::key::PublicKey;
17 use ln::channelmanager::ChannelDetails;
18 use ln::features::{ChannelFeatures, InvoiceFeatures, NodeFeatures};
19 use ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
20 use routing::scoring::Score;
21 use routing::network_graph::{DirectedChannelInfoWithUpdate, EffectiveCapacity, NetworkGraph, ReadOnlyNetworkGraph, NodeId, RoutingFees};
22 use util::ser::{Writeable, Readable};
23 use util::logger::{Level, Logger};
24 use util::chacha20::ChaCha20;
28 use alloc::collections::BinaryHeap;
33 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
35 /// The node_id of the node at this hop.
36 pub pubkey: PublicKey,
37 /// The node_announcement features of the node at this hop. For the last hop, these may be
38 /// amended to match the features present in the invoice this node generated.
39 pub node_features: NodeFeatures,
40 /// The channel that should be used from the previous hop to reach this node.
41 pub short_channel_id: u64,
42 /// The channel_announcement features of the channel that should be used from the previous hop
43 /// to reach this node.
44 pub channel_features: ChannelFeatures,
45 /// The fee taken on this hop (for paying for the use of the *next* channel in the path).
46 /// For the last hop, this should be the full value of the payment (might be more than
47 /// requested if we had to match htlc_minimum_msat).
49 /// The CLTV delta added for this hop. For the last hop, this should be the full CLTV value
50 /// expected at the destination, in excess of the current block height.
51 pub cltv_expiry_delta: u32,
54 impl_writeable_tlv_based!(RouteHop, {
55 (0, pubkey, required),
56 (2, node_features, required),
57 (4, short_channel_id, required),
58 (6, channel_features, required),
59 (8, fee_msat, required),
60 (10, cltv_expiry_delta, required),
63 /// A route directs a payment from the sender (us) to the recipient. If the recipient supports MPP,
64 /// it can take multiple paths. Each path is composed of one or more hops through the network.
65 #[derive(Clone, Hash, PartialEq, Eq)]
67 /// The list of routes taken for a single (potentially-)multi-part payment. The pubkey of the
68 /// last RouteHop in each path must be the same.
69 /// Each entry represents a list of hops, NOT INCLUDING our own, where the last hop is the
70 /// destination. Thus, this must always be at least length one. While the maximum length of any
71 /// given path is variable, keeping the length of any path to less than 20 should currently
72 /// ensure it is viable.
73 pub paths: Vec<Vec<RouteHop>>,
74 /// The `payment_params` parameter passed to [`find_route`].
75 /// This is used by `ChannelManager` to track information which may be required for retries,
76 /// provided back to you via [`Event::PaymentPathFailed`].
78 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
79 pub payment_params: Option<PaymentParameters>,
82 pub(crate) trait RoutePath {
83 /// Gets the fees for a given path, excluding any excess paid to the recipient.
84 fn get_path_fees(&self) -> u64;
86 impl RoutePath for Vec<RouteHop> {
87 fn get_path_fees(&self) -> u64 {
88 // Do not count last hop of each path since that's the full value of the payment
89 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
90 .iter().map(|hop| &hop.fee_msat)
96 /// Returns the total amount of fees paid on this [`Route`].
98 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
99 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
100 pub fn get_total_fees(&self) -> u64 {
101 self.paths.iter().map(|path| path.get_path_fees()).sum()
104 /// Returns the total amount paid on this [`Route`], excluding the fees.
105 pub fn get_total_amount(&self) -> u64 {
106 return self.paths.iter()
107 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
112 const SERIALIZATION_VERSION: u8 = 1;
113 const MIN_SERIALIZATION_VERSION: u8 = 1;
115 impl Writeable for Route {
116 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
117 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
118 (self.paths.len() as u64).write(writer)?;
119 for hops in self.paths.iter() {
120 (hops.len() as u8).write(writer)?;
121 for hop in hops.iter() {
125 write_tlv_fields!(writer, {
126 (1, self.payment_params, option),
132 impl Readable for Route {
133 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
134 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
135 let path_count: u64 = Readable::read(reader)?;
136 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
137 for _ in 0..path_count {
138 let hop_count: u8 = Readable::read(reader)?;
139 let mut hops = Vec::with_capacity(hop_count as usize);
140 for _ in 0..hop_count {
141 hops.push(Readable::read(reader)?);
145 let mut payment_params = None;
146 read_tlv_fields!(reader, {
147 (1, payment_params, option),
149 Ok(Route { paths, payment_params })
153 /// Parameters needed to find a [`Route`].
155 /// Passed to [`find_route`] and also provided in [`Event::PaymentPathFailed`] for retrying a failed
158 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
159 #[derive(Clone, Debug)]
160 pub struct RouteParameters {
161 /// The parameters of the failed payment path.
162 pub payment_params: PaymentParameters,
164 /// The amount in msats sent on the failed payment path.
165 pub final_value_msat: u64,
167 /// The CLTV on the final hop of the failed payment path.
168 pub final_cltv_expiry_delta: u32,
171 impl_writeable_tlv_based!(RouteParameters, {
172 (0, payment_params, required),
173 (2, final_value_msat, required),
174 (4, final_cltv_expiry_delta, required),
177 /// Maximum total CTLV difference we allow for a full payment path.
178 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
180 /// The median hop CLTV expiry delta currently seen in the network.
181 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
183 /// The recipient of a payment.
184 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
185 pub struct PaymentParameters {
186 /// The node id of the payee.
187 pub payee_pubkey: PublicKey,
189 /// Features supported by the payee.
191 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
192 /// does not contain any features.
194 /// [`for_keysend`]: Self::for_keysend
195 pub features: Option<InvoiceFeatures>,
197 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
198 pub route_hints: Vec<RouteHint>,
200 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
201 pub expiry_time: Option<u64>,
203 /// The maximum total CLTV delta we accept for the route.
204 pub max_total_cltv_expiry_delta: u32,
207 impl_writeable_tlv_based!(PaymentParameters, {
208 (0, payee_pubkey, required),
209 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
210 (2, features, option),
211 (4, route_hints, vec_type),
212 (6, expiry_time, option),
215 impl PaymentParameters {
216 /// Creates a payee with the node id of the given `pubkey`.
217 pub fn from_node_id(payee_pubkey: PublicKey) -> Self {
223 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
227 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
228 pub fn for_keysend(payee_pubkey: PublicKey) -> Self {
229 Self::from_node_id(payee_pubkey).with_features(InvoiceFeatures::for_keysend())
232 /// Includes the payee's features.
234 /// (C-not exported) since bindings don't support move semantics
235 pub fn with_features(self, features: InvoiceFeatures) -> Self {
236 Self { features: Some(features), ..self }
239 /// Includes hints for routing to the payee.
241 /// (C-not exported) since bindings don't support move semantics
242 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
243 Self { route_hints, ..self }
246 /// Includes a payment expiration in seconds relative to the UNIX epoch.
248 /// (C-not exported) since bindings don't support move semantics
249 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
250 Self { expiry_time: Some(expiry_time), ..self }
253 /// Includes a limit for the total CLTV expiry delta which is considered during routing
255 /// (C-not exported) since bindings don't support move semantics
256 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
257 Self { max_total_cltv_expiry_delta, ..self }
261 /// A list of hops along a payment path terminating with a channel to the recipient.
262 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
263 pub struct RouteHint(pub Vec<RouteHintHop>);
265 impl Writeable for RouteHint {
266 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
267 (self.0.len() as u64).write(writer)?;
268 for hop in self.0.iter() {
275 impl Readable for RouteHint {
276 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
277 let hop_count: u64 = Readable::read(reader)?;
278 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
279 for _ in 0..hop_count {
280 hops.push(Readable::read(reader)?);
286 /// A channel descriptor for a hop along a payment path.
287 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
288 pub struct RouteHintHop {
289 /// The node_id of the non-target end of the route
290 pub src_node_id: PublicKey,
291 /// The short_channel_id of this channel
292 pub short_channel_id: u64,
293 /// The fees which must be paid to use this channel
294 pub fees: RoutingFees,
295 /// The difference in CLTV values between this node and the next node.
296 pub cltv_expiry_delta: u16,
297 /// The minimum value, in msat, which must be relayed to the next hop.
298 pub htlc_minimum_msat: Option<u64>,
299 /// The maximum value in msat available for routing with a single HTLC.
300 pub htlc_maximum_msat: Option<u64>,
303 impl_writeable_tlv_based!(RouteHintHop, {
304 (0, src_node_id, required),
305 (1, htlc_minimum_msat, option),
306 (2, short_channel_id, required),
307 (3, htlc_maximum_msat, option),
309 (6, cltv_expiry_delta, required),
312 #[derive(Eq, PartialEq)]
313 struct RouteGraphNode {
315 lowest_fee_to_peer_through_node: u64,
316 lowest_fee_to_node: u64,
317 total_cltv_delta: u32,
318 // The maximum value a yet-to-be-constructed payment path might flow through this node.
319 // This value is upper-bounded by us by:
320 // - how much is needed for a path being constructed
321 // - how much value can channels following this node (up to the destination) can contribute,
322 // considering their capacity and fees
323 value_contribution_msat: u64,
324 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
325 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
326 path_htlc_minimum_msat: u64,
327 /// All penalties incurred from this hop on the way to the destination, as calculated using
329 path_penalty_msat: u64,
332 impl cmp::Ord for RouteGraphNode {
333 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
334 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat)
335 .checked_add(other.path_penalty_msat)
336 .unwrap_or_else(|| u64::max_value());
337 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat)
338 .checked_add(self.path_penalty_msat)
339 .unwrap_or_else(|| u64::max_value());
340 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
344 impl cmp::PartialOrd for RouteGraphNode {
345 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
346 Some(self.cmp(other))
350 /// A wrapper around the various hop representations.
352 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
353 #[derive(Clone, Debug)]
354 enum CandidateRouteHop<'a> {
355 /// A hop from the payer, where the outbound liquidity is known.
357 details: &'a ChannelDetails,
359 /// A hop found in the [`NetworkGraph`], where the channel capacity may or may not be known.
361 info: DirectedChannelInfoWithUpdate<'a>,
362 short_channel_id: u64,
364 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
366 hint: &'a RouteHintHop,
370 impl<'a> CandidateRouteHop<'a> {
371 fn short_channel_id(&self) -> u64 {
373 CandidateRouteHop::FirstHop { details } => details.short_channel_id.unwrap(),
374 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
375 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
379 // NOTE: This may alloc memory so avoid calling it in a hot code path.
380 fn features(&self) -> ChannelFeatures {
382 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
383 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
384 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
388 fn cltv_expiry_delta(&self) -> u32 {
390 CandidateRouteHop::FirstHop { .. } => 0,
391 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
392 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
396 fn htlc_minimum_msat(&self) -> u64 {
398 CandidateRouteHop::FirstHop { .. } => 0,
399 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
400 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
404 fn fees(&self) -> RoutingFees {
406 CandidateRouteHop::FirstHop { .. } => RoutingFees {
407 base_msat: 0, proportional_millionths: 0,
409 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
410 CandidateRouteHop::PrivateHop { hint } => hint.fees,
414 fn effective_capacity(&self) -> EffectiveCapacity {
416 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
417 liquidity_msat: details.outbound_capacity_msat,
419 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
420 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
425 /// It's useful to keep track of the hops associated with the fees required to use them,
426 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
427 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
428 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
430 struct PathBuildingHop<'a> {
431 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
432 // is a larger refactor and will require careful performance analysis.
434 candidate: CandidateRouteHop<'a>,
437 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
438 src_lowest_inbound_fees: RoutingFees,
439 /// All the fees paid *after* this channel on the way to the destination
440 next_hops_fee_msat: u64,
441 /// Fee paid for the use of the current channel (see candidate.fees()).
442 /// The value will be actually deducted from the counterparty balance on the previous link.
443 hop_use_fee_msat: u64,
444 /// Used to compare channels when choosing the for routing.
445 /// Includes paying for the use of a hop and the following hops, as well as
446 /// an estimated cost of reaching this hop.
447 /// Might get stale when fees are recomputed. Primarily for internal use.
449 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
450 /// walk and may be invalid thereafter.
451 path_htlc_minimum_msat: u64,
452 /// All penalties incurred from this channel on the way to the destination, as calculated using
454 path_penalty_msat: u64,
455 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
456 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
457 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
458 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
459 /// avoid processing them again.
461 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
462 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
463 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
464 // value_contribution_msat, which requires tracking it here. See comments below where it is
465 // used for more info.
466 value_contribution_msat: u64,
469 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
470 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
471 f.debug_struct("PathBuildingHop")
472 .field("node_id", &self.node_id)
473 .field("short_channel_id", &self.candidate.short_channel_id())
474 .field("total_fee_msat", &self.total_fee_msat)
475 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
476 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
477 .field("total_fee_msat - (next_hops_fee_msat + hop_use_fee_msat)", &(&self.total_fee_msat - (&self.next_hops_fee_msat + &self.hop_use_fee_msat)))
478 .field("path_penalty_msat", &self.path_penalty_msat)
479 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
480 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta())
485 // Instantiated with a list of hops with correct data in them collected during path finding,
486 // an instance of this struct should be further modified only via given methods.
488 struct PaymentPath<'a> {
489 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
492 impl<'a> PaymentPath<'a> {
493 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
494 fn get_value_msat(&self) -> u64 {
495 self.hops.last().unwrap().0.fee_msat
498 fn get_total_fee_paid_msat(&self) -> u64 {
499 if self.hops.len() < 1 {
503 // Can't use next_hops_fee_msat because it gets outdated.
504 for (i, (hop, _)) in self.hops.iter().enumerate() {
505 if i != self.hops.len() - 1 {
506 result += hop.fee_msat;
512 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
513 // to change fees may result in an inconsistency.
515 // Sometimes we call this function right after constructing a path which is inconsistent in
516 // that it the value being transferred has decreased while we were doing path finding, leading
517 // to the fees being paid not lining up with the actual limits.
519 // Note that this function is not aware of the available_liquidity limit, and thus does not
520 // support increasing the value being transferred.
521 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
522 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
524 let mut total_fee_paid_msat = 0 as u64;
525 for i in (0..self.hops.len()).rev() {
526 let last_hop = i == self.hops.len() - 1;
528 // For non-last-hop, this value will represent the fees paid on the current hop. It
529 // will consist of the fees for the use of the next hop, and extra fees to match
530 // htlc_minimum_msat of the current channel. Last hop is handled separately.
531 let mut cur_hop_fees_msat = 0;
533 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
536 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
537 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
538 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
539 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
540 // set it too high just to maliciously take more fees by exploiting this
541 // match htlc_minimum_msat logic.
542 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
543 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
544 // Note that there is a risk that *previous hops* (those closer to us, as we go
545 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
547 // This might make us end up with a broken route, although this should be super-rare
548 // in practice, both because of how healthy channels look like, and how we pick
549 // channels in add_entry.
550 // Also, this can't be exploited more heavily than *announce a free path and fail
552 cur_hop_transferred_amount_msat += extra_fees_msat;
553 total_fee_paid_msat += extra_fees_msat;
554 cur_hop_fees_msat += extra_fees_msat;
558 // Final hop is a special case: it usually has just value_msat (by design), but also
559 // it still could overpay for the htlc_minimum_msat.
560 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
562 // Propagate updated fees for the use of the channels to one hop back, where they
563 // will be actually paid (fee_msat). The last hop is handled above separately.
564 cur_hop.fee_msat = cur_hop_fees_msat;
567 // Fee for the use of the current hop which will be deducted on the previous hop.
568 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
569 // this channel is free for us.
571 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
572 cur_hop.hop_use_fee_msat = new_fee;
573 total_fee_paid_msat += new_fee;
575 // It should not be possible because this function is called only to reduce the
576 // value. In that case, compute_fee was already called with the same fees for
577 // larger amount and there was no overflow.
585 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
586 let proportional_fee_millions =
587 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
588 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
589 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
593 // This function may be (indirectly) called without any verification,
594 // with channel_fees provided by a caller. We should handle it gracefully.
599 /// Finds a route from us (payer) to the given target node (payee).
601 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
602 /// Without this, MPP will only be used if the payee's features are available in the network graph.
604 /// Private routing paths between a public node and the target may be included in `params.payee`.
606 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
607 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of our local
608 /// channels from [`NetworkGraph`] will be ignored, and only those in `first_hops` will be used.
610 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
611 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
612 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
616 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
617 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
622 /// Panics if first_hops contains channels without short_channel_ids;
623 /// [`ChannelManager::list_usable_channels`] will never include such channels.
625 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
626 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
627 pub fn find_route<L: Deref, S: Score>(
628 our_node_pubkey: &PublicKey, route_params: &RouteParameters, network: &NetworkGraph,
629 first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
630 ) -> Result<Route, LightningError>
631 where L::Target: Logger {
632 let network_graph = network.read_only();
634 our_node_pubkey, &route_params.payment_params, &network_graph, first_hops, route_params.final_value_msat,
635 route_params.final_cltv_expiry_delta, logger, scorer, random_seed_bytes
638 add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
641 Err(err) => Err(err),
645 pub(crate) fn get_route<L: Deref, S: Score>(
646 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
647 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
648 logger: L, scorer: &S, _random_seed_bytes: &[u8; 32]
649 ) -> Result<Route, LightningError>
650 where L::Target: Logger {
651 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
652 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
654 if payee_node_id == our_node_id {
655 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
658 if final_value_msat > MAX_VALUE_MSAT {
659 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
662 if final_value_msat == 0 {
663 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
666 for route in payment_params.route_hints.iter() {
667 for hop in &route.0 {
668 if hop.src_node_id == payment_params.payee_pubkey {
669 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
673 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
674 return Err(LightningError{err: "Can't find a route where the maximum total CLTV expiry delta is below the final CLTV expiry.".to_owned(), action: ErrorAction::IgnoreError});
677 // The general routing idea is the following:
678 // 1. Fill first/last hops communicated by the caller.
679 // 2. Attempt to construct a path from payer to payee for transferring
680 // any ~sufficient (described later) value.
681 // If succeed, remember which channels were used and how much liquidity they have available,
682 // so that future paths don't rely on the same liquidity.
683 // 3. Proceed to the next step if:
684 // - we hit the recommended target value;
685 // - OR if we could not construct a new path. Any next attempt will fail too.
686 // Otherwise, repeat step 2.
687 // 4. See if we managed to collect paths which aggregately are able to transfer target value
688 // (not recommended value).
689 // 5. If yes, proceed. If not, fail routing.
690 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
691 // 7. Of all the found paths, select only those with the lowest total fee.
692 // 8. The last path in every selected route is likely to be more than we need.
693 // Reduce its value-to-transfer and recompute fees.
694 // 9. Choose the best route by the lowest total fee.
696 // As for the actual search algorithm,
697 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
698 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
700 // We are not a faithful Dijkstra's implementation because we can change values which impact
701 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
702 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
703 // the value we are currently attempting to send over a path, we simply reduce the value being
704 // sent along the path for any hops after that channel. This may imply that later fees (which
705 // we've already tabulated) are lower because a smaller value is passing through the channels
706 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
707 // channels which were selected earlier (and which may still be used for other paths without a
708 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
711 // One potentially problematic case for this algorithm would be if there are many
712 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
713 // graph walking), we may never find a path which is not liquidity-limited and has lower
714 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
715 // Because we only consider paths with at least 5% of the total value being sent, the damage
716 // from such a case should be limited, however this could be further reduced in the future by
717 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
718 // limits for the purposes of fee calculation.
720 // Alternatively, we could store more detailed path information in the heap (targets, below)
721 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
722 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
723 // and practically (as we would need to store dynamically-allocated path information in heap
724 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
725 // results of such an algorithm would likely be biased towards lower-value paths.
727 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
728 // outside of our current search value, running a path search more times to gather candidate
729 // paths at different values. While this may be acceptable, further path searches may increase
730 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
731 // graph for candidate paths, calculating the maximum value which can realistically be sent at
732 // the same time, remaining generic across different payment values.
734 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
735 // to use as the A* heuristic beyond just the cost to get one node further than the current
738 let network_channels = network_graph.channels();
739 let network_nodes = network_graph.nodes();
741 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
742 // it. If the payee supports it they're supposed to include it in the invoice, so that should
744 let allow_mpp = if let Some(features) = &payment_params.features {
745 features.supports_basic_mpp()
746 } else if let Some(node) = network_nodes.get(&payee_node_id) {
747 if let Some(node_info) = node.announcement_info.as_ref() {
748 node_info.features.supports_basic_mpp()
751 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
752 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
753 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
756 // Prepare the data we'll use for payee-to-payer search by
757 // inserting first hops suggested by the caller as targets.
758 // Our search will then attempt to reach them while traversing from the payee node.
759 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
760 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
761 if let Some(hops) = first_hops {
763 if chan.short_channel_id.is_none() {
764 panic!("first_hops should be filled in with usable channels, not pending ones");
766 if chan.counterparty.node_id == *our_node_pubkey {
767 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
770 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
771 .or_insert(Vec::new())
774 if first_hop_targets.is_empty() {
775 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
779 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
780 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
781 // adding duplicate entries when we find a better path to a given node.
782 let mut targets = BinaryHeap::new();
784 // Map from node_id to information about the best current path to that node, including feerate
786 let mut dist = HashMap::with_capacity(network_nodes.len());
788 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
789 // indicating that we may wish to try again with a higher value, potentially paying to meet an
790 // htlc_minimum with extra fees while still finding a cheaper path.
791 let mut hit_minimum_limit;
793 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
794 // We start with a path_value of the exact amount we want, and if that generates a route we may
795 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
796 // amount we want in total across paths, selecting the best subset at the end.
797 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
798 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
799 let mut path_value_msat = final_value_msat;
801 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
802 // This map allows paths to be aware of the channel use by other paths in the same call.
803 // This would help to make a better path finding decisions and not "overbook" channels.
804 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
805 let mut bookkept_channels_liquidity_available_msat = HashMap::with_capacity(network_nodes.len());
807 // Keeping track of how much value we already collected across other paths. Helps to decide:
808 // - how much a new path should be transferring (upper bound);
809 // - whether a channel should be disregarded because
810 // it's available liquidity is too small comparing to how much more we need to collect;
811 // - when we want to stop looking for new paths.
812 let mut already_collected_value_msat = 0;
814 for (_, channels) in first_hop_targets.iter_mut() {
815 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
818 // First, if channels are below `recommended_value_msat`, sort them in descending order,
819 // preferring larger channels to avoid splitting the payment into more MPP parts than is
822 // Second, because simply always sorting in descending order would always use our largest
823 // available outbound capacity, needlessly fragmenting our available channel capacities,
824 // sort channels above `recommended_value_msat` in ascending order, preferring channels
825 // which have enough, but not too much, capacity for the payment.
826 channels.sort_unstable_by(|chan_a, chan_b| {
827 if chan_b.outbound_capacity_msat < recommended_value_msat || chan_a.outbound_capacity_msat < recommended_value_msat {
828 // Sort in descending order
829 chan_b.outbound_capacity_msat.cmp(&chan_a.outbound_capacity_msat)
831 // Sort in ascending order
832 chan_a.outbound_capacity_msat.cmp(&chan_b.outbound_capacity_msat)
837 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
839 macro_rules! add_entry {
840 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
841 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
842 // since that value has to be transferred over this channel.
843 // Returns whether this channel caused an update to `targets`.
844 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
845 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
846 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr ) => { {
847 // We "return" whether we updated the path at the end, via this:
848 let mut did_add_update_path_to_src_node = false;
849 // Channels to self should not be used. This is more of belt-and-suspenders, because in
850 // practice these cases should be caught earlier:
851 // - for regular channels at channel announcement (TODO)
852 // - for first and last hops early in get_route
853 if $src_node_id != $dest_node_id {
854 let short_channel_id = $candidate.short_channel_id();
855 let available_liquidity_msat = bookkept_channels_liquidity_available_msat
856 .entry(short_channel_id)
857 .or_insert_with(|| $candidate.effective_capacity().as_msat());
859 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
860 // It may be misleading because we might later choose to reduce the value transferred
861 // over these channels, and the channel which was insufficient might become sufficient.
862 // Worst case: we drop a good channel here because it can't cover the high following
863 // fees caused by one expensive channel, but then this channel could have been used
864 // if the amount being transferred over this path is lower.
865 // We do this for now, but this is a subject for removal.
866 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
868 // Routing Fragmentation Mitigation heuristic:
870 // Routing fragmentation across many payment paths increases the overall routing
871 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
872 // Taking too many smaller paths also increases the chance of payment failure.
873 // Thus to avoid this effect, we require from our collected links to provide
874 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
876 // This requirement is currently 5% of the remaining-to-be-collected value.
877 // This means as we successfully advance in our collection,
878 // the absolute liquidity contribution is lowered,
879 // thus increasing the number of potential channels to be selected.
881 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
882 // or 100% if we're not allowed to do multipath payments.
883 let minimal_value_contribution_msat: u64 = if allow_mpp {
884 (recommended_value_msat - already_collected_value_msat + 19) / 20
888 // Verify the liquidity offered by this channel complies to the minimal contribution.
889 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
891 // Do not consider candidates that exceed the maximum total cltv expiry limit.
892 // In order to already account for some of the privacy enhancing random CLTV
893 // expiry delta offset we add on top later, we subtract a rough estimate
894 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
895 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
896 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
897 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
898 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
899 .checked_add($candidate.cltv_expiry_delta())
900 .unwrap_or(u32::max_value());
901 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
903 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
904 // Includes paying fees for the use of the following channels.
905 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
906 Some(result) => result,
907 // Can't overflow due to how the values were computed right above.
908 None => unreachable!(),
910 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
911 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
912 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
914 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
915 // bother considering this channel.
916 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
917 // be only reduced later (not increased), so this channel should just be skipped
918 // as not sufficient.
919 if !over_path_minimum_msat && doesnt_exceed_cltv_delta_limit {
920 hit_minimum_limit = true;
921 } else if contributes_sufficient_value && doesnt_exceed_cltv_delta_limit {
922 // Note that low contribution here (limited by available_liquidity_msat)
923 // might violate htlc_minimum_msat on the hops which are next along the
924 // payment path (upstream to the payee). To avoid that, we recompute
925 // path fees knowing the final path contribution after constructing it.
926 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
927 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
928 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
929 .unwrap_or_else(|| u64::max_value());
930 let hm_entry = dist.entry($src_node_id);
931 let old_entry = hm_entry.or_insert_with(|| {
932 // If there was previously no known way to access the source node
933 // (recall it goes payee-to-payer) of short_channel_id, first add a
934 // semi-dummy record just to compute the fees to reach the source node.
935 // This will affect our decision on selecting short_channel_id
936 // as a way to reach the $dest_node_id.
937 let mut fee_base_msat = 0;
938 let mut fee_proportional_millionths = 0;
939 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
940 fee_base_msat = fees.base_msat;
941 fee_proportional_millionths = fees.proportional_millionths;
944 node_id: $dest_node_id.clone(),
945 candidate: $candidate.clone(),
947 src_lowest_inbound_fees: RoutingFees {
948 base_msat: fee_base_msat,
949 proportional_millionths: fee_proportional_millionths,
951 next_hops_fee_msat: u64::max_value(),
952 hop_use_fee_msat: u64::max_value(),
953 total_fee_msat: u64::max_value(),
954 path_htlc_minimum_msat,
955 path_penalty_msat: u64::max_value(),
956 was_processed: false,
957 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
958 value_contribution_msat,
962 #[allow(unused_mut)] // We only use the mut in cfg(test)
963 let mut should_process = !old_entry.was_processed;
964 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
966 // In test/fuzzing builds, we do extra checks to make sure the skipping
967 // of already-seen nodes only happens in cases we expect (see below).
968 if !should_process { should_process = true; }
972 let mut hop_use_fee_msat = 0;
973 let mut total_fee_msat = $next_hops_fee_msat;
975 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
976 // will have the same effective-fee
977 if $src_node_id != our_node_id {
978 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
979 // max_value means we'll always fail
980 // the old_entry.total_fee_msat > total_fee_msat check
981 None => total_fee_msat = u64::max_value(),
983 hop_use_fee_msat = fee_msat;
984 total_fee_msat += hop_use_fee_msat;
985 // When calculating the lowest inbound fees to a node, we
986 // calculate fees here not based on the actual value we think
987 // will flow over this channel, but on the minimum value that
988 // we'll accept flowing over it. The minimum accepted value
989 // is a constant through each path collection run, ensuring
990 // consistent basis. Otherwise we may later find a
991 // different path to the source node that is more expensive,
992 // but which we consider to be cheaper because we are capacity
993 // constrained and the relative fee becomes lower.
994 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
995 .map(|a| a.checked_add(total_fee_msat)) {
1000 total_fee_msat = u64::max_value();
1007 let path_penalty_msat = $next_hops_path_penalty_msat.checked_add(
1008 scorer.channel_penalty_msat(short_channel_id, amount_to_transfer_over_msat, *available_liquidity_msat,
1009 &$src_node_id, &$dest_node_id)).unwrap_or_else(|| u64::max_value());
1010 let new_graph_node = RouteGraphNode {
1011 node_id: $src_node_id,
1012 lowest_fee_to_peer_through_node: total_fee_msat,
1013 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1014 total_cltv_delta: hop_total_cltv_delta,
1015 value_contribution_msat: value_contribution_msat,
1016 path_htlc_minimum_msat,
1020 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1021 // if this way is cheaper than the already known
1022 // (considering the cost to "reach" this channel from the route destination,
1023 // the cost of using this channel,
1024 // and the cost of routing to the source node of this channel).
1025 // Also, consider that htlc_minimum_msat_difference, because we might end up
1026 // paying it. Consider the following exploit:
1027 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1028 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1029 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1030 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1032 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1033 // but it may require additional tracking - we don't want to double-count
1034 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1035 // can't use something that may decrease on future hops.
1036 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1037 .checked_add(old_entry.path_penalty_msat)
1038 .unwrap_or_else(|| u64::max_value());
1039 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1040 .checked_add(path_penalty_msat)
1041 .unwrap_or_else(|| u64::max_value());
1043 if !old_entry.was_processed && new_cost < old_cost {
1044 targets.push(new_graph_node);
1045 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1046 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1047 old_entry.total_fee_msat = total_fee_msat;
1048 old_entry.node_id = $dest_node_id.clone();
1049 old_entry.candidate = $candidate.clone();
1050 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1051 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1052 old_entry.path_penalty_msat = path_penalty_msat;
1053 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1055 old_entry.value_contribution_msat = value_contribution_msat;
1057 did_add_update_path_to_src_node = true;
1058 } else if old_entry.was_processed && new_cost < old_cost {
1059 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1061 // If we're skipping processing a node which was previously
1062 // processed even though we found another path to it with a
1063 // cheaper fee, check that it was because the second path we
1064 // found (which we are processing now) has a lower value
1065 // contribution due to an HTLC minimum limit.
1067 // e.g. take a graph with two paths from node 1 to node 2, one
1068 // through channel A, and one through channel B. Channel A and
1069 // B are both in the to-process heap, with their scores set by
1070 // a higher htlc_minimum than fee.
1071 // Channel A is processed first, and the channels onwards from
1072 // node 1 are added to the to-process heap. Thereafter, we pop
1073 // Channel B off of the heap, note that it has a much more
1074 // restrictive htlc_maximum_msat, and recalculate the fees for
1075 // all of node 1's channels using the new, reduced, amount.
1077 // This would be bogus - we'd be selecting a higher-fee path
1078 // with a lower htlc_maximum_msat instead of the one we'd
1079 // already decided to use.
1080 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1082 value_contribution_msat + path_penalty_msat <
1083 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1091 did_add_update_path_to_src_node
1095 let empty_node_features = NodeFeatures::empty();
1096 // Find ways (channels with destination) to reach a given node and store them
1097 // in the corresponding data structures (routing graph etc).
1098 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1099 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1100 // This data can later be helpful to optimize routing (pay lower fees).
1101 macro_rules! add_entries_to_cheapest_to_target_node {
1102 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr ) => {
1103 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1104 let was_processed = elem.was_processed;
1105 elem.was_processed = true;
1108 // Entries are added to dist in add_entry!() when there is a channel from a node.
1109 // Because there are no channels from payee, it will not have a dist entry at this point.
1110 // If we're processing any other node, it is always be the result of a channel from it.
1111 assert_eq!($node_id, payee_node_id);
1116 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1117 for details in first_channels {
1118 let candidate = CandidateRouteHop::FirstHop { details };
1119 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat, $next_hops_cltv_delta);
1123 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1126 &empty_node_features
1129 if !features.requires_unknown_bits() {
1130 for chan_id in $node.channels.iter() {
1131 let chan = network_channels.get(chan_id).unwrap();
1132 if !chan.features.requires_unknown_bits() {
1133 let (directed_channel, source) =
1134 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1135 if first_hops.is_none() || *source != our_node_id {
1136 if let Some(direction) = directed_channel.direction() {
1137 if direction.enabled {
1138 let candidate = CandidateRouteHop::PublicHop {
1139 info: directed_channel.with_update().unwrap(),
1140 short_channel_id: *chan_id,
1142 add_entry!(candidate, *source, $node_id, $fee_to_target_msat, $next_hops_value_contribution, $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat, $next_hops_cltv_delta);
1153 let mut payment_paths = Vec::<PaymentPath>::new();
1155 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1156 'paths_collection: loop {
1157 // For every new path, start from scratch, except
1158 // bookkept_channels_liquidity_available_msat, which will improve
1159 // the further iterations of path finding. Also don't erase first_hop_targets.
1162 hit_minimum_limit = false;
1164 // If first hop is a private channel and the only way to reach the payee, this is the only
1165 // place where it could be added.
1166 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1167 for details in first_channels {
1168 let candidate = CandidateRouteHop::FirstHop { details };
1169 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1170 log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1174 // Add the payee as a target, so that the payee-to-payer
1175 // search algorithm knows what to start with.
1176 match network_nodes.get(&payee_node_id) {
1177 // The payee is not in our network graph, so nothing to add here.
1178 // There is still a chance of reaching them via last_hops though,
1179 // so don't yet fail the payment here.
1180 // If not, targets.pop() will not even let us enter the loop in step 2.
1183 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1188 // If a caller provided us with last hops, add them to routing targets. Since this happens
1189 // earlier than general path finding, they will be somewhat prioritized, although currently
1190 // it matters only if the fees are exactly the same.
1191 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1192 let first_hop_in_route = &(route.0)[0];
1193 let have_hop_src_in_graph =
1194 // Only add the hops in this route to our candidate set if either
1195 // we have a direct channel to the first hop or the first hop is
1196 // in the regular network graph.
1197 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1198 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1199 if have_hop_src_in_graph {
1200 // We start building the path from reverse, i.e., from payee
1201 // to the first RouteHintHop in the path.
1202 let hop_iter = route.0.iter().rev();
1203 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1204 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1205 let mut hop_used = true;
1206 let mut aggregate_next_hops_fee_msat: u64 = 0;
1207 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1208 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1209 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1211 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1212 let source = NodeId::from_pubkey(&hop.src_node_id);
1213 let target = NodeId::from_pubkey(&prev_hop_id);
1214 let candidate = network_channels
1215 .get(&hop.short_channel_id)
1216 .and_then(|channel| channel.as_directed_to(&target))
1217 .and_then(|(channel, _)| channel.with_update())
1218 .map(|info| CandidateRouteHop::PublicHop {
1220 short_channel_id: hop.short_channel_id,
1222 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1223 let capacity_msat = candidate.effective_capacity().as_msat();
1224 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1225 .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, capacity_msat, &source, &target))
1226 .unwrap_or_else(|| u64::max_value());
1228 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1229 .checked_add(hop.cltv_expiry_delta as u32)
1230 .unwrap_or_else(|| u32::max_value());
1232 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta) {
1233 // If this hop was not used then there is no use checking the preceding hops
1234 // in the RouteHint. We can break by just searching for a direct channel between
1235 // last checked hop and first_hop_targets
1239 // Searching for a direct channel between last checked hop and first_hop_targets
1240 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1241 for details in first_channels {
1242 let candidate = CandidateRouteHop::FirstHop { details };
1243 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta);
1251 // In the next values of the iterator, the aggregate fees already reflects
1252 // the sum of value sent from payer (final_value_msat) and routing fees
1253 // for the last node in the RouteHint. We need to just add the fees to
1254 // route through the current node so that the preceeding node (next iteration)
1256 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1257 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1258 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1260 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1261 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1262 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1263 .checked_add(hop_htlc_minimum_msat_inc);
1264 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1266 if idx == route.0.len() - 1 {
1267 // The last hop in this iterator is the first hop in
1268 // overall RouteHint.
1269 // If this hop connects to a node with which we have a direct channel,
1270 // ignore the network graph and, if the last hop was added, add our
1271 // direct channel to the candidate set.
1273 // Note that we *must* check if the last hop was added as `add_entry`
1274 // always assumes that the third argument is a node to which we have a
1276 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1277 for details in first_channels {
1278 let candidate = CandidateRouteHop::FirstHop { details };
1279 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&hop.src_node_id), aggregate_next_hops_fee_msat, path_value_msat, aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta);
1287 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1289 // At this point, targets are filled with the data from first and
1290 // last hops communicated by the caller, and the payment receiver.
1291 let mut found_new_path = false;
1294 // If this loop terminates due the exhaustion of targets, two situations are possible:
1295 // - not enough outgoing liquidity:
1296 // 0 < already_collected_value_msat < final_value_msat
1297 // - enough outgoing liquidity:
1298 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1299 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1300 // paths_collection will be stopped because found_new_path==false.
1301 // This is not necessarily a routing failure.
1302 'path_construction: while let Some(RouteGraphNode { node_id, lowest_fee_to_node, total_cltv_delta, value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, .. }) = targets.pop() {
1304 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1305 // traversing the graph and arrange the path out of what we found.
1306 if node_id == our_node_id {
1307 let mut new_entry = dist.remove(&our_node_id).unwrap();
1308 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
1311 let mut features_set = false;
1312 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1313 for details in first_channels {
1314 if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1315 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1316 features_set = true;
1322 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1323 if let Some(node_info) = node.announcement_info.as_ref() {
1324 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1326 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
1329 // We can fill in features for everything except hops which were
1330 // provided via the invoice we're paying. We could guess based on the
1331 // recipient's features but for now we simply avoid guessing at all.
1335 // Means we succesfully traversed from the payer to the payee, now
1336 // save this path for the payment route. Also, update the liquidity
1337 // remaining on the used hops, so that we take them into account
1338 // while looking for more paths.
1339 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1343 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1344 Some(payment_hop) => payment_hop,
1345 // We can't arrive at None because, if we ever add an entry to targets,
1346 // we also fill in the entry in dist (see add_entry!).
1347 None => unreachable!(),
1349 // We "propagate" the fees one hop backward (topologically) here,
1350 // so that fees paid for a HTLC forwarding on the current channel are
1351 // associated with the previous channel (where they will be subtracted).
1352 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1353 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
1355 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1356 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1358 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1359 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1361 let mut payment_path = PaymentPath {hops: ordered_hops};
1363 // We could have possibly constructed a slightly inconsistent path: since we reduce
1364 // value being transferred along the way, we could have violated htlc_minimum_msat
1365 // on some channels we already passed (assuming dest->source direction). Here, we
1366 // recompute the fees again, so that if that's the case, we match the currently
1367 // underpaid htlc_minimum_msat with fees.
1368 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1370 // Since a path allows to transfer as much value as
1371 // the smallest channel it has ("bottleneck"), we should recompute
1372 // the fees so sender HTLC don't overpay fees when traversing
1373 // larger channels than the bottleneck. This may happen because
1374 // when we were selecting those channels we were not aware how much value
1375 // this path will transfer, and the relative fee for them
1376 // might have been computed considering a larger value.
1377 // Remember that we used these channels so that we don't rely
1378 // on the same liquidity in future paths.
1379 let mut prevented_redundant_path_selection = false;
1380 for (payment_hop, _) in payment_path.hops.iter() {
1381 let channel_liquidity_available_msat = bookkept_channels_liquidity_available_msat.get_mut(&payment_hop.candidate.short_channel_id()).unwrap();
1382 let mut spent_on_hop_msat = value_contribution_msat;
1383 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
1384 spent_on_hop_msat += next_hops_fee_msat;
1385 if spent_on_hop_msat == *channel_liquidity_available_msat {
1386 // If this path used all of this channel's available liquidity, we know
1387 // this path will not be selected again in the next loop iteration.
1388 prevented_redundant_path_selection = true;
1390 *channel_liquidity_available_msat -= spent_on_hop_msat;
1392 if !prevented_redundant_path_selection {
1393 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1394 // we'll probably end up picking the same path again on the next iteration.
1395 // Decrease the available liquidity of a hop in the middle of the path.
1396 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.candidate.short_channel_id();
1397 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1398 let victim_liquidity = bookkept_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1399 *victim_liquidity = 0;
1402 // Track the total amount all our collected paths allow to send so that we:
1403 // - know when to stop looking for more paths
1404 // - know which of the hops are useless considering how much more sats we need
1405 // (contributes_sufficient_value)
1406 already_collected_value_msat += value_contribution_msat;
1408 payment_paths.push(payment_path);
1409 found_new_path = true;
1410 break 'path_construction;
1413 // If we found a path back to the payee, we shouldn't try to process it again. This is
1414 // the equivalent of the `elem.was_processed` check in
1415 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1416 if node_id == payee_node_id { continue 'path_construction; }
1418 // Otherwise, since the current target node is not us,
1419 // keep "unrolling" the payment graph from payee to payer by
1420 // finding a way to reach the current target from the payer side.
1421 match network_nodes.get(&node_id) {
1424 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node, value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat, total_cltv_delta);
1430 // If we don't support MPP, no use trying to gather more value ever.
1431 break 'paths_collection;
1435 // Stop either when the recommended value is reached or if no new path was found in this
1437 // In the latter case, making another path finding attempt won't help,
1438 // because we deterministically terminated the search due to low liquidity.
1439 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1440 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1441 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1442 break 'paths_collection;
1443 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1444 // Further, if this was our first walk of the graph, and we weren't limited by an
1445 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1446 // limited by an htlc_minimum_msat value, find another path with a higher value,
1447 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1448 // still keeping a lower total fee than this path.
1449 if !hit_minimum_limit {
1450 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1451 break 'paths_collection;
1453 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1454 path_value_msat = recommended_value_msat;
1459 if payment_paths.len() == 0 {
1460 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1463 if already_collected_value_msat < final_value_msat {
1464 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1467 // Sort by total fees and take the best paths.
1468 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1469 if payment_paths.len() > 50 {
1470 payment_paths.truncate(50);
1473 // Draw multiple sufficient routes by randomly combining the selected paths.
1474 let mut drawn_routes = Vec::new();
1475 for i in 0..payment_paths.len() {
1476 let mut cur_route = Vec::<PaymentPath>::new();
1477 let mut aggregate_route_value_msat = 0;
1480 // TODO: real random shuffle
1481 // Currently just starts with i_th and goes up to i-1_th in a looped way.
1482 let cur_payment_paths = [&payment_paths[i..], &payment_paths[..i]].concat();
1485 for payment_path in cur_payment_paths {
1486 cur_route.push(payment_path.clone());
1487 aggregate_route_value_msat += payment_path.get_value_msat();
1488 if aggregate_route_value_msat > final_value_msat {
1489 // Last path likely overpaid. Substract it from the most expensive
1490 // (in terms of proportional fee) path in this route and recompute fees.
1491 // This might be not the most economically efficient way, but fewer paths
1492 // also makes routing more reliable.
1493 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1495 // First, drop some expensive low-value paths entirely if possible.
1496 // Sort by value so that we drop many really-low values first, since
1497 // fewer paths is better: the payment is less likely to fail.
1498 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1499 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1500 cur_route.sort_by_key(|path| path.get_value_msat());
1501 // We should make sure that at least 1 path left.
1502 let mut paths_left = cur_route.len();
1503 cur_route.retain(|path| {
1504 if paths_left == 1 {
1507 let mut keep = true;
1508 let path_value_msat = path.get_value_msat();
1509 if path_value_msat <= overpaid_value_msat {
1511 overpaid_value_msat -= path_value_msat;
1517 if overpaid_value_msat == 0 {
1521 assert!(cur_route.len() > 0);
1524 // Now, substract the overpaid value from the most-expensive path.
1525 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1526 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1527 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1528 let expensive_payment_path = cur_route.first_mut().unwrap();
1529 // We already dropped all the small channels above, meaning all the
1530 // remaining channels are larger than remaining overpaid_value_msat.
1531 // Thus, this can't be negative.
1532 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1533 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1537 drawn_routes.push(cur_route);
1541 // Select the best route by lowest total fee.
1542 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1543 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1544 for payment_path in drawn_routes.first().unwrap() {
1545 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1547 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)})?,
1548 node_features: node_features.clone(),
1549 short_channel_id: payment_hop.candidate.short_channel_id(),
1550 channel_features: payment_hop.candidate.features(),
1551 fee_msat: payment_hop.fee_msat,
1552 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1554 }).collect::<Vec<_>>();
1555 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1556 // applicable for the previous hop.
1557 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1558 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1560 selected_paths.push(path);
1563 if let Some(features) = &payment_params.features {
1564 for path in selected_paths.iter_mut() {
1565 if let Ok(route_hop) = path.last_mut().unwrap() {
1566 route_hop.node_features = features.to_context();
1572 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1573 payment_params: Some(payment_params.clone()),
1575 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1579 // When an adversarial intermediary node observes a payment, it may be able to infer its
1580 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1581 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1582 // payment path by adding a randomized 'shadow route' offset to the final hop.
1583 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]) {
1584 let network_channels = network_graph.channels();
1585 let network_nodes = network_graph.nodes();
1587 for path in route.paths.iter_mut() {
1588 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1590 // Choose the last publicly known node as the starting point for the random walk
1591 if let Some(starting_hop) = path.iter().rev().find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1592 let mut cur_node_id = NodeId::from_pubkey(&starting_hop.pubkey);
1594 // Init PRNG with path nonce
1595 let mut path_nonce = [0u8; 12];
1596 path_nonce.copy_from_slice(&cur_node_id.as_slice()[..12]);
1597 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1598 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1600 // Pick a random path length in [1 .. 3]
1601 prng.process_in_place(&mut random_path_bytes);
1602 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1604 for _random_hop in 0..random_walk_length {
1605 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1606 // Randomly choose the next hop
1607 prng.process_in_place(&mut random_path_bytes);
1608 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes).checked_rem(cur_node.channels.len())
1609 .and_then(|index| cur_node.channels.get(index))
1610 .and_then(|id| network_channels.get(id)) {
1611 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1612 dir_info.direction().map(|channel_update_info|
1613 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1614 .checked_add(channel_update_info.cltv_expiry_delta.into())
1615 .unwrap_or(shadow_ctlv_expiry_delta_offset));
1616 cur_node_id = *next_id;
1622 // If the entire path is private, choose a random offset from multiples of
1623 // MEDIAN_HOP_CLTV_EXPIRY_DELTA
1624 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 8]);
1625 let mut random_bytes = [0u8; 4];
1626 prng.process_in_place(&mut random_bytes);
1627 let random_walk_length = u32::from_be_bytes(random_bytes).wrapping_rem(3).wrapping_add(1);
1628 shadow_ctlv_expiry_delta_offset = random_walk_length * MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1631 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1632 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1633 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1635 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1636 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1637 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1638 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1639 max_path_offset = cmp::max(
1640 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1641 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1642 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1644 // Add 'shadow' CLTV offset to the final hop
1645 if let Some(last_hop) = path.last_mut() {
1646 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1647 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1654 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler, NodeId};
1655 use routing::router::{get_route, add_random_cltv_offset, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA};
1656 use routing::scoring::Score;
1657 use chain::transaction::OutPoint;
1658 use chain::keysinterface::KeysInterface;
1659 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1660 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1661 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1662 use ln::channelmanager;
1663 use util::test_utils;
1664 use util::chacha20::ChaCha20;
1665 use util::ser::Writeable;
1667 use util::ser::Writer;
1669 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1670 use bitcoin::hashes::Hash;
1671 use bitcoin::network::constants::Network;
1672 use bitcoin::blockdata::constants::genesis_block;
1673 use bitcoin::blockdata::script::Builder;
1674 use bitcoin::blockdata::opcodes;
1675 use bitcoin::blockdata::transaction::TxOut;
1679 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1680 use bitcoin::secp256k1::{Secp256k1, All};
1683 use sync::{self, Arc};
1685 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1686 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1687 channelmanager::ChannelDetails {
1688 channel_id: [0; 32],
1689 counterparty: channelmanager::ChannelCounterparty {
1692 unspendable_punishment_reserve: 0,
1693 forwarding_info: None,
1695 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1697 inbound_scid_alias: None,
1698 channel_value_satoshis: 0,
1701 outbound_capacity_msat,
1702 inbound_capacity_msat: 42,
1703 unspendable_punishment_reserve: None,
1704 confirmations_required: None,
1705 force_close_spend_delay: None,
1706 is_outbound: true, is_funding_locked: true,
1707 is_usable: true, is_public: true,
1711 // Using the same keys for LN and BTC ids
1713 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1714 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1716 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1717 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1719 let unsigned_announcement = UnsignedChannelAnnouncement {
1721 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1725 bitcoin_key_1: node_id_1,
1726 bitcoin_key_2: node_id_2,
1727 excess_data: Vec::new(),
1730 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1731 let valid_announcement = ChannelAnnouncement {
1732 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1733 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1734 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1735 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1736 contents: unsigned_announcement.clone(),
1738 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1739 Ok(res) => assert!(res),
1745 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1746 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1748 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1749 let valid_channel_update = ChannelUpdate {
1750 signature: secp_ctx.sign(&msghash, node_privkey),
1751 contents: update.clone()
1754 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1755 Ok(res) => assert!(res),
1760 fn add_or_update_node(
1761 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1762 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1764 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1765 let unsigned_announcement = UnsignedNodeAnnouncement {
1771 addresses: Vec::new(),
1772 excess_address_data: Vec::new(),
1773 excess_data: Vec::new(),
1775 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1776 let valid_announcement = NodeAnnouncement {
1777 signature: secp_ctx.sign(&msghash, node_privkey),
1778 contents: unsigned_announcement.clone()
1781 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1787 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1788 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1789 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
1792 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1794 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1795 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1797 (our_privkey, our_id, privkeys, pubkeys)
1800 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1801 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1802 // test for it later.
1803 let idx = (id - 1) * 2 + 1;
1805 vec![1 << (idx - 8*3), 0, 0, 0]
1806 } else if idx > 8*2 {
1807 vec![1 << (idx - 8*2), 0, 0]
1808 } else if idx > 8*1 {
1809 vec![1 << (idx - 8*1), 0]
1815 fn build_graph() -> (
1817 sync::Arc<NetworkGraph>,
1818 NetGraphMsgHandler<sync::Arc<NetworkGraph>, sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>,
1819 sync::Arc<test_utils::TestChainSource>,
1820 sync::Arc<test_utils::TestLogger>,
1822 let secp_ctx = Secp256k1::new();
1823 let logger = Arc::new(test_utils::TestLogger::new());
1824 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1825 let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
1826 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
1827 // Build network from our_id to node6:
1829 // -1(1)2- node0 -1(3)2-
1831 // our_id -1(12)2- node7 -1(13)2--- node2
1833 // -1(2)2- node1 -1(4)2-
1836 // chan1 1-to-2: disabled
1837 // chan1 2-to-1: enabled, 0 fee
1839 // chan2 1-to-2: enabled, ignored fee
1840 // chan2 2-to-1: enabled, 0 fee
1842 // chan3 1-to-2: enabled, 0 fee
1843 // chan3 2-to-1: enabled, 100 msat fee
1845 // chan4 1-to-2: enabled, 100% fee
1846 // chan4 2-to-1: enabled, 0 fee
1848 // chan12 1-to-2: enabled, ignored fee
1849 // chan12 2-to-1: enabled, 0 fee
1851 // chan13 1-to-2: enabled, 200% fee
1852 // chan13 2-to-1: enabled, 0 fee
1855 // -1(5)2- node3 -1(8)2--
1859 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1861 // -1(7)2- node5 -1(10)2-
1863 // Channels 5, 8, 9 and 10 are private channels.
1865 // chan5 1-to-2: enabled, 100 msat fee
1866 // chan5 2-to-1: enabled, 0 fee
1868 // chan6 1-to-2: enabled, 0 fee
1869 // chan6 2-to-1: enabled, 0 fee
1871 // chan7 1-to-2: enabled, 100% fee
1872 // chan7 2-to-1: enabled, 0 fee
1874 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1875 // chan8 2-to-1: enabled, 0 fee
1877 // chan9 1-to-2: enabled, 1001 msat fee
1878 // chan9 2-to-1: enabled, 0 fee
1880 // chan10 1-to-2: enabled, 0 fee
1881 // chan10 2-to-1: enabled, 0 fee
1883 // chan11 1-to-2: enabled, 0 fee
1884 // chan11 2-to-1: enabled, 0 fee
1886 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1888 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1889 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1890 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1891 short_channel_id: 1,
1894 cltv_expiry_delta: 0,
1895 htlc_minimum_msat: 0,
1896 htlc_maximum_msat: OptionalField::Absent,
1898 fee_proportional_millionths: 0,
1899 excess_data: Vec::new()
1902 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1904 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1905 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1906 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1907 short_channel_id: 2,
1910 cltv_expiry_delta: (5 << 4) | 3,
1911 htlc_minimum_msat: 0,
1912 htlc_maximum_msat: OptionalField::Absent,
1913 fee_base_msat: u32::max_value(),
1914 fee_proportional_millionths: u32::max_value(),
1915 excess_data: Vec::new()
1917 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1918 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1919 short_channel_id: 2,
1922 cltv_expiry_delta: 0,
1923 htlc_minimum_msat: 0,
1924 htlc_maximum_msat: OptionalField::Absent,
1926 fee_proportional_millionths: 0,
1927 excess_data: Vec::new()
1930 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1932 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1933 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1934 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1935 short_channel_id: 12,
1938 cltv_expiry_delta: (5 << 4) | 3,
1939 htlc_minimum_msat: 0,
1940 htlc_maximum_msat: OptionalField::Absent,
1941 fee_base_msat: u32::max_value(),
1942 fee_proportional_millionths: u32::max_value(),
1943 excess_data: Vec::new()
1945 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1946 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1947 short_channel_id: 12,
1950 cltv_expiry_delta: 0,
1951 htlc_minimum_msat: 0,
1952 htlc_maximum_msat: OptionalField::Absent,
1954 fee_proportional_millionths: 0,
1955 excess_data: Vec::new()
1958 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1960 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1961 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1962 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1963 short_channel_id: 3,
1966 cltv_expiry_delta: (3 << 4) | 1,
1967 htlc_minimum_msat: 0,
1968 htlc_maximum_msat: OptionalField::Absent,
1970 fee_proportional_millionths: 0,
1971 excess_data: Vec::new()
1973 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1974 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1975 short_channel_id: 3,
1978 cltv_expiry_delta: (3 << 4) | 2,
1979 htlc_minimum_msat: 0,
1980 htlc_maximum_msat: OptionalField::Absent,
1982 fee_proportional_millionths: 0,
1983 excess_data: Vec::new()
1986 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1987 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1988 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1989 short_channel_id: 4,
1992 cltv_expiry_delta: (4 << 4) | 1,
1993 htlc_minimum_msat: 0,
1994 htlc_maximum_msat: OptionalField::Absent,
1996 fee_proportional_millionths: 1000000,
1997 excess_data: Vec::new()
1999 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2000 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2001 short_channel_id: 4,
2004 cltv_expiry_delta: (4 << 4) | 2,
2005 htlc_minimum_msat: 0,
2006 htlc_maximum_msat: OptionalField::Absent,
2008 fee_proportional_millionths: 0,
2009 excess_data: Vec::new()
2012 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2013 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2014 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2015 short_channel_id: 13,
2018 cltv_expiry_delta: (13 << 4) | 1,
2019 htlc_minimum_msat: 0,
2020 htlc_maximum_msat: OptionalField::Absent,
2022 fee_proportional_millionths: 2000000,
2023 excess_data: Vec::new()
2025 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2026 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2027 short_channel_id: 13,
2030 cltv_expiry_delta: (13 << 4) | 2,
2031 htlc_minimum_msat: 0,
2032 htlc_maximum_msat: OptionalField::Absent,
2034 fee_proportional_millionths: 0,
2035 excess_data: Vec::new()
2038 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2040 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2041 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2042 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2043 short_channel_id: 6,
2046 cltv_expiry_delta: (6 << 4) | 1,
2047 htlc_minimum_msat: 0,
2048 htlc_maximum_msat: OptionalField::Absent,
2050 fee_proportional_millionths: 0,
2051 excess_data: Vec::new()
2053 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2054 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2055 short_channel_id: 6,
2058 cltv_expiry_delta: (6 << 4) | 2,
2059 htlc_minimum_msat: 0,
2060 htlc_maximum_msat: OptionalField::Absent,
2062 fee_proportional_millionths: 0,
2063 excess_data: Vec::new(),
2066 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2067 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2068 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2069 short_channel_id: 11,
2072 cltv_expiry_delta: (11 << 4) | 1,
2073 htlc_minimum_msat: 0,
2074 htlc_maximum_msat: OptionalField::Absent,
2076 fee_proportional_millionths: 0,
2077 excess_data: Vec::new()
2079 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2080 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2081 short_channel_id: 11,
2084 cltv_expiry_delta: (11 << 4) | 2,
2085 htlc_minimum_msat: 0,
2086 htlc_maximum_msat: OptionalField::Absent,
2088 fee_proportional_millionths: 0,
2089 excess_data: Vec::new()
2092 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2094 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2096 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2097 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2098 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2099 short_channel_id: 7,
2102 cltv_expiry_delta: (7 << 4) | 1,
2103 htlc_minimum_msat: 0,
2104 htlc_maximum_msat: OptionalField::Absent,
2106 fee_proportional_millionths: 1000000,
2107 excess_data: Vec::new()
2109 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2110 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2111 short_channel_id: 7,
2114 cltv_expiry_delta: (7 << 4) | 2,
2115 htlc_minimum_msat: 0,
2116 htlc_maximum_msat: OptionalField::Absent,
2118 fee_proportional_millionths: 0,
2119 excess_data: Vec::new()
2122 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2124 (secp_ctx, network_graph, net_graph_msg_handler, chain_monitor, logger)
2128 fn simple_route_test() {
2129 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2130 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2131 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2132 let scorer = test_utils::TestScorer::with_penalty(0);
2133 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2134 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2136 // Simple route to 2 via 1
2138 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 0, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2139 assert_eq!(err, "Cannot send a payment of 0 msat");
2140 } else { panic!(); }
2142 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2143 assert_eq!(route.paths[0].len(), 2);
2145 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2146 assert_eq!(route.paths[0][0].short_channel_id, 2);
2147 assert_eq!(route.paths[0][0].fee_msat, 100);
2148 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2149 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2150 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2152 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2153 assert_eq!(route.paths[0][1].short_channel_id, 4);
2154 assert_eq!(route.paths[0][1].fee_msat, 100);
2155 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2156 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2157 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2161 fn invalid_first_hop_test() {
2162 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2163 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2164 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2165 let scorer = test_utils::TestScorer::with_penalty(0);
2166 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2167 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2169 // Simple route to 2 via 1
2171 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2173 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2174 get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2175 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2176 } else { panic!(); }
2178 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2179 assert_eq!(route.paths[0].len(), 2);
2183 fn htlc_minimum_test() {
2184 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2185 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2186 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2187 let scorer = test_utils::TestScorer::with_penalty(0);
2188 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2189 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2191 // Simple route to 2 via 1
2193 // Disable other paths
2194 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2195 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2196 short_channel_id: 12,
2198 flags: 2, // to disable
2199 cltv_expiry_delta: 0,
2200 htlc_minimum_msat: 0,
2201 htlc_maximum_msat: OptionalField::Absent,
2203 fee_proportional_millionths: 0,
2204 excess_data: Vec::new()
2206 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2207 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2208 short_channel_id: 3,
2210 flags: 2, // to disable
2211 cltv_expiry_delta: 0,
2212 htlc_minimum_msat: 0,
2213 htlc_maximum_msat: OptionalField::Absent,
2215 fee_proportional_millionths: 0,
2216 excess_data: Vec::new()
2218 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2219 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2220 short_channel_id: 13,
2222 flags: 2, // to disable
2223 cltv_expiry_delta: 0,
2224 htlc_minimum_msat: 0,
2225 htlc_maximum_msat: OptionalField::Absent,
2227 fee_proportional_millionths: 0,
2228 excess_data: Vec::new()
2230 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2231 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2232 short_channel_id: 6,
2234 flags: 2, // to disable
2235 cltv_expiry_delta: 0,
2236 htlc_minimum_msat: 0,
2237 htlc_maximum_msat: OptionalField::Absent,
2239 fee_proportional_millionths: 0,
2240 excess_data: Vec::new()
2242 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2243 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2244 short_channel_id: 7,
2246 flags: 2, // to disable
2247 cltv_expiry_delta: 0,
2248 htlc_minimum_msat: 0,
2249 htlc_maximum_msat: OptionalField::Absent,
2251 fee_proportional_millionths: 0,
2252 excess_data: Vec::new()
2255 // Check against amount_to_transfer_over_msat.
2256 // Set minimal HTLC of 200_000_000 msat.
2257 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2258 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2259 short_channel_id: 2,
2262 cltv_expiry_delta: 0,
2263 htlc_minimum_msat: 200_000_000,
2264 htlc_maximum_msat: OptionalField::Absent,
2266 fee_proportional_millionths: 0,
2267 excess_data: Vec::new()
2270 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2272 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2273 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2274 short_channel_id: 4,
2277 cltv_expiry_delta: 0,
2278 htlc_minimum_msat: 0,
2279 htlc_maximum_msat: OptionalField::Present(199_999_999),
2281 fee_proportional_millionths: 0,
2282 excess_data: Vec::new()
2285 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2286 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2287 assert_eq!(err, "Failed to find a path to the given destination");
2288 } else { panic!(); }
2290 // Lift the restriction on the first hop.
2291 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2292 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2293 short_channel_id: 2,
2296 cltv_expiry_delta: 0,
2297 htlc_minimum_msat: 0,
2298 htlc_maximum_msat: OptionalField::Absent,
2300 fee_proportional_millionths: 0,
2301 excess_data: Vec::new()
2304 // A payment above the minimum should pass
2305 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 199_999_999, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2306 assert_eq!(route.paths[0].len(), 2);
2310 fn htlc_minimum_overpay_test() {
2311 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2312 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2313 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2314 let scorer = test_utils::TestScorer::with_penalty(0);
2315 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2316 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2318 // A route to node#2 via two paths.
2319 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2320 // Thus, they can't send 60 without overpaying.
2321 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2322 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2323 short_channel_id: 2,
2326 cltv_expiry_delta: 0,
2327 htlc_minimum_msat: 35_000,
2328 htlc_maximum_msat: OptionalField::Present(40_000),
2330 fee_proportional_millionths: 0,
2331 excess_data: Vec::new()
2333 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2334 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2335 short_channel_id: 12,
2338 cltv_expiry_delta: 0,
2339 htlc_minimum_msat: 35_000,
2340 htlc_maximum_msat: OptionalField::Present(40_000),
2342 fee_proportional_millionths: 0,
2343 excess_data: Vec::new()
2347 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2348 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2349 short_channel_id: 13,
2352 cltv_expiry_delta: 0,
2353 htlc_minimum_msat: 0,
2354 htlc_maximum_msat: OptionalField::Absent,
2356 fee_proportional_millionths: 0,
2357 excess_data: Vec::new()
2359 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2360 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2361 short_channel_id: 4,
2364 cltv_expiry_delta: 0,
2365 htlc_minimum_msat: 0,
2366 htlc_maximum_msat: OptionalField::Absent,
2368 fee_proportional_millionths: 0,
2369 excess_data: Vec::new()
2372 // Disable other paths
2373 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2374 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2375 short_channel_id: 1,
2377 flags: 2, // to disable
2378 cltv_expiry_delta: 0,
2379 htlc_minimum_msat: 0,
2380 htlc_maximum_msat: OptionalField::Absent,
2382 fee_proportional_millionths: 0,
2383 excess_data: Vec::new()
2386 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2387 // Overpay fees to hit htlc_minimum_msat.
2388 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2389 // TODO: this could be better balanced to overpay 10k and not 15k.
2390 assert_eq!(overpaid_fees, 15_000);
2392 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2393 // while taking even more fee to match htlc_minimum_msat.
2394 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2395 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2396 short_channel_id: 12,
2399 cltv_expiry_delta: 0,
2400 htlc_minimum_msat: 65_000,
2401 htlc_maximum_msat: OptionalField::Present(80_000),
2403 fee_proportional_millionths: 0,
2404 excess_data: Vec::new()
2406 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2407 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2408 short_channel_id: 2,
2411 cltv_expiry_delta: 0,
2412 htlc_minimum_msat: 0,
2413 htlc_maximum_msat: OptionalField::Absent,
2415 fee_proportional_millionths: 0,
2416 excess_data: Vec::new()
2418 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2419 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2420 short_channel_id: 4,
2423 cltv_expiry_delta: 0,
2424 htlc_minimum_msat: 0,
2425 htlc_maximum_msat: OptionalField::Absent,
2427 fee_proportional_millionths: 100_000,
2428 excess_data: Vec::new()
2431 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2432 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2433 assert_eq!(route.paths.len(), 1);
2434 assert_eq!(route.paths[0][0].short_channel_id, 12);
2435 let fees = route.paths[0][0].fee_msat;
2436 assert_eq!(fees, 5_000);
2438 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2439 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2440 // the other channel.
2441 assert_eq!(route.paths.len(), 1);
2442 assert_eq!(route.paths[0][0].short_channel_id, 2);
2443 let fees = route.paths[0][0].fee_msat;
2444 assert_eq!(fees, 5_000);
2448 fn disable_channels_test() {
2449 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2450 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2451 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2452 let scorer = test_utils::TestScorer::with_penalty(0);
2453 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2454 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2456 // // Disable channels 4 and 12 by flags=2
2457 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2458 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2459 short_channel_id: 4,
2461 flags: 2, // to disable
2462 cltv_expiry_delta: 0,
2463 htlc_minimum_msat: 0,
2464 htlc_maximum_msat: OptionalField::Absent,
2466 fee_proportional_millionths: 0,
2467 excess_data: Vec::new()
2469 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2470 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2471 short_channel_id: 12,
2473 flags: 2, // to disable
2474 cltv_expiry_delta: 0,
2475 htlc_minimum_msat: 0,
2476 htlc_maximum_msat: OptionalField::Absent,
2478 fee_proportional_millionths: 0,
2479 excess_data: Vec::new()
2482 // If all the channels require some features we don't understand, route should fail
2483 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2484 assert_eq!(err, "Failed to find a path to the given destination");
2485 } else { panic!(); }
2487 // If we specify a channel to node7, that overrides our local channel view and that gets used
2488 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2489 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2490 assert_eq!(route.paths[0].len(), 2);
2492 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2493 assert_eq!(route.paths[0][0].short_channel_id, 42);
2494 assert_eq!(route.paths[0][0].fee_msat, 200);
2495 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2496 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2497 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2499 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2500 assert_eq!(route.paths[0][1].short_channel_id, 13);
2501 assert_eq!(route.paths[0][1].fee_msat, 100);
2502 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2503 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2504 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2508 fn disable_node_test() {
2509 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2510 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2511 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2512 let scorer = test_utils::TestScorer::with_penalty(0);
2513 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2514 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2516 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2517 let mut unknown_features = NodeFeatures::known();
2518 unknown_features.set_unknown_feature_required();
2519 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2520 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2521 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2523 // If all nodes require some features we don't understand, route should fail
2524 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2525 assert_eq!(err, "Failed to find a path to the given destination");
2526 } else { panic!(); }
2528 // If we specify a channel to node7, that overrides our local channel view and that gets used
2529 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2530 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2531 assert_eq!(route.paths[0].len(), 2);
2533 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2534 assert_eq!(route.paths[0][0].short_channel_id, 42);
2535 assert_eq!(route.paths[0][0].fee_msat, 200);
2536 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2537 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2538 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2540 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2541 assert_eq!(route.paths[0][1].short_channel_id, 13);
2542 assert_eq!(route.paths[0][1].fee_msat, 100);
2543 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2544 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2545 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2547 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2548 // naively) assume that the user checked the feature bits on the invoice, which override
2549 // the node_announcement.
2553 fn our_chans_test() {
2554 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2555 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2556 let scorer = test_utils::TestScorer::with_penalty(0);
2557 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2558 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2560 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2561 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2562 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2563 assert_eq!(route.paths[0].len(), 3);
2565 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2566 assert_eq!(route.paths[0][0].short_channel_id, 2);
2567 assert_eq!(route.paths[0][0].fee_msat, 200);
2568 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2569 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2570 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2572 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2573 assert_eq!(route.paths[0][1].short_channel_id, 4);
2574 assert_eq!(route.paths[0][1].fee_msat, 100);
2575 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2576 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2577 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2579 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2580 assert_eq!(route.paths[0][2].short_channel_id, 3);
2581 assert_eq!(route.paths[0][2].fee_msat, 100);
2582 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2583 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2584 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2586 // If we specify a channel to node7, that overrides our local channel view and that gets used
2587 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2588 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2589 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2590 assert_eq!(route.paths[0].len(), 2);
2592 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2593 assert_eq!(route.paths[0][0].short_channel_id, 42);
2594 assert_eq!(route.paths[0][0].fee_msat, 200);
2595 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2596 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2597 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2599 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2600 assert_eq!(route.paths[0][1].short_channel_id, 13);
2601 assert_eq!(route.paths[0][1].fee_msat, 100);
2602 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2603 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2604 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2607 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2608 let zero_fees = RoutingFees {
2610 proportional_millionths: 0,
2612 vec![RouteHint(vec![RouteHintHop {
2613 src_node_id: nodes[3],
2614 short_channel_id: 8,
2616 cltv_expiry_delta: (8 << 4) | 1,
2617 htlc_minimum_msat: None,
2618 htlc_maximum_msat: None,
2620 ]), RouteHint(vec![RouteHintHop {
2621 src_node_id: nodes[4],
2622 short_channel_id: 9,
2625 proportional_millionths: 0,
2627 cltv_expiry_delta: (9 << 4) | 1,
2628 htlc_minimum_msat: None,
2629 htlc_maximum_msat: None,
2630 }]), RouteHint(vec![RouteHintHop {
2631 src_node_id: nodes[5],
2632 short_channel_id: 10,
2634 cltv_expiry_delta: (10 << 4) | 1,
2635 htlc_minimum_msat: None,
2636 htlc_maximum_msat: None,
2640 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2641 let zero_fees = RoutingFees {
2643 proportional_millionths: 0,
2645 vec![RouteHint(vec![RouteHintHop {
2646 src_node_id: nodes[2],
2647 short_channel_id: 5,
2650 proportional_millionths: 0,
2652 cltv_expiry_delta: (5 << 4) | 1,
2653 htlc_minimum_msat: None,
2654 htlc_maximum_msat: None,
2656 src_node_id: nodes[3],
2657 short_channel_id: 8,
2659 cltv_expiry_delta: (8 << 4) | 1,
2660 htlc_minimum_msat: None,
2661 htlc_maximum_msat: None,
2663 ]), RouteHint(vec![RouteHintHop {
2664 src_node_id: nodes[4],
2665 short_channel_id: 9,
2668 proportional_millionths: 0,
2670 cltv_expiry_delta: (9 << 4) | 1,
2671 htlc_minimum_msat: None,
2672 htlc_maximum_msat: None,
2673 }]), RouteHint(vec![RouteHintHop {
2674 src_node_id: nodes[5],
2675 short_channel_id: 10,
2677 cltv_expiry_delta: (10 << 4) | 1,
2678 htlc_minimum_msat: None,
2679 htlc_maximum_msat: None,
2684 fn partial_route_hint_test() {
2685 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2686 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2687 let scorer = test_utils::TestScorer::with_penalty(0);
2688 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2689 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2691 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2692 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2693 // RouteHint may be partially used by the algo to build the best path.
2695 // First check that last hop can't have its source as the payee.
2696 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2697 src_node_id: nodes[6],
2698 short_channel_id: 8,
2701 proportional_millionths: 0,
2703 cltv_expiry_delta: (8 << 4) | 1,
2704 htlc_minimum_msat: None,
2705 htlc_maximum_msat: None,
2708 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2709 invalid_last_hops.push(invalid_last_hop);
2711 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2712 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
2713 assert_eq!(err, "Route hint cannot have the payee as the source.");
2714 } else { panic!(); }
2717 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
2718 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2719 assert_eq!(route.paths[0].len(), 5);
2721 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2722 assert_eq!(route.paths[0][0].short_channel_id, 2);
2723 assert_eq!(route.paths[0][0].fee_msat, 100);
2724 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2725 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2726 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2728 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2729 assert_eq!(route.paths[0][1].short_channel_id, 4);
2730 assert_eq!(route.paths[0][1].fee_msat, 0);
2731 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2732 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2733 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2735 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2736 assert_eq!(route.paths[0][2].short_channel_id, 6);
2737 assert_eq!(route.paths[0][2].fee_msat, 0);
2738 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2739 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2740 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2742 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2743 assert_eq!(route.paths[0][3].short_channel_id, 11);
2744 assert_eq!(route.paths[0][3].fee_msat, 0);
2745 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2746 // If we have a peer in the node map, we'll use their features here since we don't have
2747 // a way of figuring out their features from the invoice:
2748 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2749 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2751 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2752 assert_eq!(route.paths[0][4].short_channel_id, 8);
2753 assert_eq!(route.paths[0][4].fee_msat, 100);
2754 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2755 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2756 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2759 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2760 let zero_fees = RoutingFees {
2762 proportional_millionths: 0,
2764 vec![RouteHint(vec![RouteHintHop {
2765 src_node_id: nodes[3],
2766 short_channel_id: 8,
2768 cltv_expiry_delta: (8 << 4) | 1,
2769 htlc_minimum_msat: None,
2770 htlc_maximum_msat: None,
2771 }]), RouteHint(vec![
2773 ]), RouteHint(vec![RouteHintHop {
2774 src_node_id: nodes[5],
2775 short_channel_id: 10,
2777 cltv_expiry_delta: (10 << 4) | 1,
2778 htlc_minimum_msat: None,
2779 htlc_maximum_msat: None,
2784 fn ignores_empty_last_hops_test() {
2785 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2786 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2787 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
2788 let scorer = test_utils::TestScorer::with_penalty(0);
2789 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2790 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2792 // Test handling of an empty RouteHint passed in Invoice.
2794 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2795 assert_eq!(route.paths[0].len(), 5);
2797 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2798 assert_eq!(route.paths[0][0].short_channel_id, 2);
2799 assert_eq!(route.paths[0][0].fee_msat, 100);
2800 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2801 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2802 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2804 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2805 assert_eq!(route.paths[0][1].short_channel_id, 4);
2806 assert_eq!(route.paths[0][1].fee_msat, 0);
2807 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2808 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2809 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2811 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2812 assert_eq!(route.paths[0][2].short_channel_id, 6);
2813 assert_eq!(route.paths[0][2].fee_msat, 0);
2814 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2815 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2816 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2818 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2819 assert_eq!(route.paths[0][3].short_channel_id, 11);
2820 assert_eq!(route.paths[0][3].fee_msat, 0);
2821 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2822 // If we have a peer in the node map, we'll use their features here since we don't have
2823 // a way of figuring out their features from the invoice:
2824 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2825 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2827 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2828 assert_eq!(route.paths[0][4].short_channel_id, 8);
2829 assert_eq!(route.paths[0][4].fee_msat, 100);
2830 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2831 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2832 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2835 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
2837 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
2838 let zero_fees = RoutingFees {
2840 proportional_millionths: 0,
2842 vec![RouteHint(vec![RouteHintHop {
2843 src_node_id: hint_hops[0],
2844 short_channel_id: 0xff00,
2847 proportional_millionths: 0,
2849 cltv_expiry_delta: (5 << 4) | 1,
2850 htlc_minimum_msat: None,
2851 htlc_maximum_msat: None,
2853 src_node_id: hint_hops[1],
2854 short_channel_id: 0xff01,
2856 cltv_expiry_delta: (8 << 4) | 1,
2857 htlc_minimum_msat: None,
2858 htlc_maximum_msat: None,
2863 fn multi_hint_last_hops_test() {
2864 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2865 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2866 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
2867 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2868 let scorer = test_utils::TestScorer::with_penalty(0);
2869 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2870 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2871 // Test through channels 2, 3, 0xff00, 0xff01.
2872 // Test shows that multiple hop hints are considered.
2874 // Disabling channels 6 & 7 by flags=2
2875 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2876 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2877 short_channel_id: 6,
2879 flags: 2, // to disable
2880 cltv_expiry_delta: 0,
2881 htlc_minimum_msat: 0,
2882 htlc_maximum_msat: OptionalField::Absent,
2884 fee_proportional_millionths: 0,
2885 excess_data: Vec::new()
2887 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2888 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2889 short_channel_id: 7,
2891 flags: 2, // to disable
2892 cltv_expiry_delta: 0,
2893 htlc_minimum_msat: 0,
2894 htlc_maximum_msat: OptionalField::Absent,
2896 fee_proportional_millionths: 0,
2897 excess_data: Vec::new()
2900 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2901 assert_eq!(route.paths[0].len(), 4);
2903 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2904 assert_eq!(route.paths[0][0].short_channel_id, 2);
2905 assert_eq!(route.paths[0][0].fee_msat, 200);
2906 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2907 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2908 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2910 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2911 assert_eq!(route.paths[0][1].short_channel_id, 4);
2912 assert_eq!(route.paths[0][1].fee_msat, 100);
2913 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2914 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2915 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2917 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
2918 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
2919 assert_eq!(route.paths[0][2].fee_msat, 0);
2920 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2921 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
2922 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2924 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2925 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
2926 assert_eq!(route.paths[0][3].fee_msat, 100);
2927 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2928 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2929 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2933 fn private_multi_hint_last_hops_test() {
2934 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2935 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2937 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
2938 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
2940 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
2941 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2942 let scorer = test_utils::TestScorer::with_penalty(0);
2943 // Test through channels 2, 3, 0xff00, 0xff01.
2944 // Test shows that multiple hop hints are considered.
2946 // Disabling channels 6 & 7 by flags=2
2947 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2948 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2949 short_channel_id: 6,
2951 flags: 2, // to disable
2952 cltv_expiry_delta: 0,
2953 htlc_minimum_msat: 0,
2954 htlc_maximum_msat: OptionalField::Absent,
2956 fee_proportional_millionths: 0,
2957 excess_data: Vec::new()
2959 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2960 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2961 short_channel_id: 7,
2963 flags: 2, // to disable
2964 cltv_expiry_delta: 0,
2965 htlc_minimum_msat: 0,
2966 htlc_maximum_msat: OptionalField::Absent,
2968 fee_proportional_millionths: 0,
2969 excess_data: Vec::new()
2972 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
2973 assert_eq!(route.paths[0].len(), 4);
2975 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2976 assert_eq!(route.paths[0][0].short_channel_id, 2);
2977 assert_eq!(route.paths[0][0].fee_msat, 200);
2978 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2979 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2980 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2982 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2983 assert_eq!(route.paths[0][1].short_channel_id, 4);
2984 assert_eq!(route.paths[0][1].fee_msat, 100);
2985 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2986 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2987 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2989 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
2990 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
2991 assert_eq!(route.paths[0][2].fee_msat, 0);
2992 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2993 assert_eq!(route.paths[0][2].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2994 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2996 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2997 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
2998 assert_eq!(route.paths[0][3].fee_msat, 100);
2999 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3000 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3001 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3004 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3005 let zero_fees = RoutingFees {
3007 proportional_millionths: 0,
3009 vec![RouteHint(vec![RouteHintHop {
3010 src_node_id: nodes[4],
3011 short_channel_id: 11,
3013 cltv_expiry_delta: (11 << 4) | 1,
3014 htlc_minimum_msat: None,
3015 htlc_maximum_msat: None,
3017 src_node_id: nodes[3],
3018 short_channel_id: 8,
3020 cltv_expiry_delta: (8 << 4) | 1,
3021 htlc_minimum_msat: None,
3022 htlc_maximum_msat: None,
3023 }]), RouteHint(vec![RouteHintHop {
3024 src_node_id: nodes[4],
3025 short_channel_id: 9,
3028 proportional_millionths: 0,
3030 cltv_expiry_delta: (9 << 4) | 1,
3031 htlc_minimum_msat: None,
3032 htlc_maximum_msat: None,
3033 }]), RouteHint(vec![RouteHintHop {
3034 src_node_id: nodes[5],
3035 short_channel_id: 10,
3037 cltv_expiry_delta: (10 << 4) | 1,
3038 htlc_minimum_msat: None,
3039 htlc_maximum_msat: None,
3044 fn last_hops_with_public_channel_test() {
3045 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3046 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3047 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3048 let scorer = test_utils::TestScorer::with_penalty(0);
3049 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3050 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3051 // This test shows that public routes can be present in the invoice
3052 // which would be handled in the same manner.
3054 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3055 assert_eq!(route.paths[0].len(), 5);
3057 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3058 assert_eq!(route.paths[0][0].short_channel_id, 2);
3059 assert_eq!(route.paths[0][0].fee_msat, 100);
3060 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3061 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3062 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3064 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3065 assert_eq!(route.paths[0][1].short_channel_id, 4);
3066 assert_eq!(route.paths[0][1].fee_msat, 0);
3067 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3068 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3069 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3071 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3072 assert_eq!(route.paths[0][2].short_channel_id, 6);
3073 assert_eq!(route.paths[0][2].fee_msat, 0);
3074 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3075 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3076 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3078 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3079 assert_eq!(route.paths[0][3].short_channel_id, 11);
3080 assert_eq!(route.paths[0][3].fee_msat, 0);
3081 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3082 // If we have a peer in the node map, we'll use their features here since we don't have
3083 // a way of figuring out their features from the invoice:
3084 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3085 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3087 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3088 assert_eq!(route.paths[0][4].short_channel_id, 8);
3089 assert_eq!(route.paths[0][4].fee_msat, 100);
3090 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3091 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3092 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3096 fn our_chans_last_hop_connect_test() {
3097 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3098 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3099 let scorer = test_utils::TestScorer::with_penalty(0);
3100 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3101 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3103 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3104 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3105 let mut last_hops = last_hops(&nodes);
3106 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3107 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3108 assert_eq!(route.paths[0].len(), 2);
3110 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3111 assert_eq!(route.paths[0][0].short_channel_id, 42);
3112 assert_eq!(route.paths[0][0].fee_msat, 0);
3113 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3114 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3115 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3117 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3118 assert_eq!(route.paths[0][1].short_channel_id, 8);
3119 assert_eq!(route.paths[0][1].fee_msat, 100);
3120 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3121 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3122 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3124 last_hops[0].0[0].fees.base_msat = 1000;
3126 // Revert to via 6 as the fee on 8 goes up
3127 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3128 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3129 assert_eq!(route.paths[0].len(), 4);
3131 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3132 assert_eq!(route.paths[0][0].short_channel_id, 2);
3133 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3134 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3135 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3136 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3138 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3139 assert_eq!(route.paths[0][1].short_channel_id, 4);
3140 assert_eq!(route.paths[0][1].fee_msat, 100);
3141 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3142 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3143 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3145 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3146 assert_eq!(route.paths[0][2].short_channel_id, 7);
3147 assert_eq!(route.paths[0][2].fee_msat, 0);
3148 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3149 // If we have a peer in the node map, we'll use their features here since we don't have
3150 // a way of figuring out their features from the invoice:
3151 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3152 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3154 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3155 assert_eq!(route.paths[0][3].short_channel_id, 10);
3156 assert_eq!(route.paths[0][3].fee_msat, 100);
3157 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3158 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3159 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3161 // ...but still use 8 for larger payments as 6 has a variable feerate
3162 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3163 assert_eq!(route.paths[0].len(), 5);
3165 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3166 assert_eq!(route.paths[0][0].short_channel_id, 2);
3167 assert_eq!(route.paths[0][0].fee_msat, 3000);
3168 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3169 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3170 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3172 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3173 assert_eq!(route.paths[0][1].short_channel_id, 4);
3174 assert_eq!(route.paths[0][1].fee_msat, 0);
3175 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3176 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3177 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3179 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3180 assert_eq!(route.paths[0][2].short_channel_id, 6);
3181 assert_eq!(route.paths[0][2].fee_msat, 0);
3182 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3183 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3184 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3186 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3187 assert_eq!(route.paths[0][3].short_channel_id, 11);
3188 assert_eq!(route.paths[0][3].fee_msat, 1000);
3189 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3190 // If we have a peer in the node map, we'll use their features here since we don't have
3191 // a way of figuring out their features from the invoice:
3192 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3193 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3195 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3196 assert_eq!(route.paths[0][4].short_channel_id, 8);
3197 assert_eq!(route.paths[0][4].fee_msat, 2000);
3198 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3199 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3200 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3203 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> {
3204 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3205 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3206 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3208 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3209 let last_hops = RouteHint(vec![RouteHintHop {
3210 src_node_id: middle_node_id,
3211 short_channel_id: 8,
3214 proportional_millionths: last_hop_fee_prop,
3216 cltv_expiry_delta: (8 << 4) | 1,
3217 htlc_minimum_msat: None,
3218 htlc_maximum_msat: last_hop_htlc_max,
3220 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3221 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3222 let scorer = test_utils::TestScorer::with_penalty(0);
3223 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3224 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3225 get_route(&source_node_id, &payment_params, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()).read_only(),
3226 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes)
3230 fn unannounced_path_test() {
3231 // We should be able to send a payment to a destination without any help of a routing graph
3232 // if we have a channel with a common counterparty that appears in the first and last hop
3234 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3236 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3237 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3238 assert_eq!(route.paths[0].len(), 2);
3240 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3241 assert_eq!(route.paths[0][0].short_channel_id, 42);
3242 assert_eq!(route.paths[0][0].fee_msat, 1001);
3243 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3244 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3245 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3247 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3248 assert_eq!(route.paths[0][1].short_channel_id, 8);
3249 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3250 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3251 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
3252 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3256 fn overflow_unannounced_path_test_liquidity_underflow() {
3257 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3258 // the last-hop had a fee which overflowed a u64, we'd panic.
3259 // This was due to us adding the first-hop from us unconditionally, causing us to think
3260 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3261 // In this test, we previously hit a subtraction underflow due to having less available
3262 // liquidity at the last hop than 0.
3263 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());
3267 fn overflow_unannounced_path_test_feerate_overflow() {
3268 // This tests for the same case as above, except instead of hitting a subtraction
3269 // underflow, we hit a case where the fee charged at a hop overflowed.
3270 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());
3274 fn available_amount_while_routing_test() {
3275 // Tests whether we choose the correct available channel amount while routing.
3277 let (secp_ctx, network_graph, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
3278 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3279 let scorer = test_utils::TestScorer::with_penalty(0);
3280 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3281 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3282 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3284 // We will use a simple single-path route from
3285 // our node to node2 via node0: channels {1, 3}.
3287 // First disable all other paths.
3288 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3289 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3290 short_channel_id: 2,
3293 cltv_expiry_delta: 0,
3294 htlc_minimum_msat: 0,
3295 htlc_maximum_msat: OptionalField::Present(100_000),
3297 fee_proportional_millionths: 0,
3298 excess_data: Vec::new()
3300 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3301 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3302 short_channel_id: 12,
3305 cltv_expiry_delta: 0,
3306 htlc_minimum_msat: 0,
3307 htlc_maximum_msat: OptionalField::Present(100_000),
3309 fee_proportional_millionths: 0,
3310 excess_data: Vec::new()
3313 // Make the first channel (#1) very permissive,
3314 // and we will be testing all limits on the second channel.
3315 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3316 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3317 short_channel_id: 1,
3320 cltv_expiry_delta: 0,
3321 htlc_minimum_msat: 0,
3322 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3324 fee_proportional_millionths: 0,
3325 excess_data: Vec::new()
3328 // First, let's see if routing works if we have absolutely no idea about the available amount.
3329 // In this case, it should be set to 250_000 sats.
3330 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3331 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3332 short_channel_id: 3,
3335 cltv_expiry_delta: 0,
3336 htlc_minimum_msat: 0,
3337 htlc_maximum_msat: OptionalField::Absent,
3339 fee_proportional_millionths: 0,
3340 excess_data: Vec::new()
3344 // Attempt to route more than available results in a failure.
3345 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3346 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3347 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3348 } else { panic!(); }
3352 // Now, attempt to route an exact amount we have should be fine.
3353 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3354 assert_eq!(route.paths.len(), 1);
3355 let path = route.paths.last().unwrap();
3356 assert_eq!(path.len(), 2);
3357 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3358 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3361 // Check that setting outbound_capacity_msat in first_hops limits the channels.
3362 // Disable channel #1 and use another first hop.
3363 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3364 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3365 short_channel_id: 1,
3368 cltv_expiry_delta: 0,
3369 htlc_minimum_msat: 0,
3370 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3372 fee_proportional_millionths: 0,
3373 excess_data: Vec::new()
3376 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
3377 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3380 // Attempt to route more than available results in a failure.
3381 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3382 &our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3383 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3384 } else { panic!(); }
3388 // Now, attempt to route an exact amount we have should be fine.
3389 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&our_chans.iter().collect::<Vec<_>>()), 200_000_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3390 assert_eq!(route.paths.len(), 1);
3391 let path = route.paths.last().unwrap();
3392 assert_eq!(path.len(), 2);
3393 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3394 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3397 // Enable channel #1 back.
3398 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3399 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3400 short_channel_id: 1,
3403 cltv_expiry_delta: 0,
3404 htlc_minimum_msat: 0,
3405 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3407 fee_proportional_millionths: 0,
3408 excess_data: Vec::new()
3412 // Now let's see if routing works if we know only htlc_maximum_msat.
3413 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3414 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3415 short_channel_id: 3,
3418 cltv_expiry_delta: 0,
3419 htlc_minimum_msat: 0,
3420 htlc_maximum_msat: OptionalField::Present(15_000),
3422 fee_proportional_millionths: 0,
3423 excess_data: Vec::new()
3427 // Attempt to route more than available results in a failure.
3428 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3429 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3430 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3431 } else { panic!(); }
3435 // Now, attempt to route an exact amount we have should be fine.
3436 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3437 assert_eq!(route.paths.len(), 1);
3438 let path = route.paths.last().unwrap();
3439 assert_eq!(path.len(), 2);
3440 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3441 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3444 // Now let's see if routing works if we know only capacity from the UTXO.
3446 // We can't change UTXO capacity on the fly, so we'll disable
3447 // the existing channel and add another one with the capacity we need.
3448 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3449 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3450 short_channel_id: 3,
3453 cltv_expiry_delta: 0,
3454 htlc_minimum_msat: 0,
3455 htlc_maximum_msat: OptionalField::Absent,
3457 fee_proportional_millionths: 0,
3458 excess_data: Vec::new()
3461 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3462 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3463 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3464 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3465 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3467 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3468 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
3470 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3471 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3472 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3473 short_channel_id: 333,
3476 cltv_expiry_delta: (3 << 4) | 1,
3477 htlc_minimum_msat: 0,
3478 htlc_maximum_msat: OptionalField::Absent,
3480 fee_proportional_millionths: 0,
3481 excess_data: Vec::new()
3483 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3484 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3485 short_channel_id: 333,
3488 cltv_expiry_delta: (3 << 4) | 2,
3489 htlc_minimum_msat: 0,
3490 htlc_maximum_msat: OptionalField::Absent,
3492 fee_proportional_millionths: 0,
3493 excess_data: Vec::new()
3497 // Attempt to route more than available results in a failure.
3498 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3499 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3500 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3501 } else { panic!(); }
3505 // Now, attempt to route an exact amount we have should be fine.
3506 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3507 assert_eq!(route.paths.len(), 1);
3508 let path = route.paths.last().unwrap();
3509 assert_eq!(path.len(), 2);
3510 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3511 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3514 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3515 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3516 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3517 short_channel_id: 333,
3520 cltv_expiry_delta: 0,
3521 htlc_minimum_msat: 0,
3522 htlc_maximum_msat: OptionalField::Present(10_000),
3524 fee_proportional_millionths: 0,
3525 excess_data: Vec::new()
3529 // Attempt to route more than available results in a failure.
3530 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3531 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3532 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3533 } else { panic!(); }
3537 // Now, attempt to route an exact amount we have should be fine.
3538 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3539 assert_eq!(route.paths.len(), 1);
3540 let path = route.paths.last().unwrap();
3541 assert_eq!(path.len(), 2);
3542 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3543 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3548 fn available_liquidity_last_hop_test() {
3549 // Check that available liquidity properly limits the path even when only
3550 // one of the latter hops is limited.
3551 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3552 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3553 let scorer = test_utils::TestScorer::with_penalty(0);
3554 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3555 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3556 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3558 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3559 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3560 // Total capacity: 50 sats.
3562 // Disable other potential paths.
3563 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3564 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3565 short_channel_id: 2,
3568 cltv_expiry_delta: 0,
3569 htlc_minimum_msat: 0,
3570 htlc_maximum_msat: OptionalField::Present(100_000),
3572 fee_proportional_millionths: 0,
3573 excess_data: Vec::new()
3575 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3576 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3577 short_channel_id: 7,
3580 cltv_expiry_delta: 0,
3581 htlc_minimum_msat: 0,
3582 htlc_maximum_msat: OptionalField::Present(100_000),
3584 fee_proportional_millionths: 0,
3585 excess_data: Vec::new()
3590 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3591 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3592 short_channel_id: 12,
3595 cltv_expiry_delta: 0,
3596 htlc_minimum_msat: 0,
3597 htlc_maximum_msat: OptionalField::Present(100_000),
3599 fee_proportional_millionths: 0,
3600 excess_data: Vec::new()
3602 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3603 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3604 short_channel_id: 13,
3607 cltv_expiry_delta: 0,
3608 htlc_minimum_msat: 0,
3609 htlc_maximum_msat: OptionalField::Present(100_000),
3611 fee_proportional_millionths: 0,
3612 excess_data: Vec::new()
3615 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3616 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3617 short_channel_id: 6,
3620 cltv_expiry_delta: 0,
3621 htlc_minimum_msat: 0,
3622 htlc_maximum_msat: OptionalField::Present(50_000),
3624 fee_proportional_millionths: 0,
3625 excess_data: Vec::new()
3627 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3628 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3629 short_channel_id: 11,
3632 cltv_expiry_delta: 0,
3633 htlc_minimum_msat: 0,
3634 htlc_maximum_msat: OptionalField::Present(100_000),
3636 fee_proportional_millionths: 0,
3637 excess_data: Vec::new()
3640 // Attempt to route more than available results in a failure.
3641 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3642 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3643 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3644 } else { panic!(); }
3648 // Now, attempt to route 49 sats (just a bit below the capacity).
3649 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3650 assert_eq!(route.paths.len(), 1);
3651 let mut total_amount_paid_msat = 0;
3652 for path in &route.paths {
3653 assert_eq!(path.len(), 4);
3654 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3655 total_amount_paid_msat += path.last().unwrap().fee_msat;
3657 assert_eq!(total_amount_paid_msat, 49_000);
3661 // Attempt to route an exact amount is also fine
3662 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3663 assert_eq!(route.paths.len(), 1);
3664 let mut total_amount_paid_msat = 0;
3665 for path in &route.paths {
3666 assert_eq!(path.len(), 4);
3667 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3668 total_amount_paid_msat += path.last().unwrap().fee_msat;
3670 assert_eq!(total_amount_paid_msat, 50_000);
3675 fn ignore_fee_first_hop_test() {
3676 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3677 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3678 let scorer = test_utils::TestScorer::with_penalty(0);
3679 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3680 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3681 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3683 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3684 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3685 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3686 short_channel_id: 1,
3689 cltv_expiry_delta: 0,
3690 htlc_minimum_msat: 0,
3691 htlc_maximum_msat: OptionalField::Present(100_000),
3692 fee_base_msat: 1_000_000,
3693 fee_proportional_millionths: 0,
3694 excess_data: Vec::new()
3696 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3697 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3698 short_channel_id: 3,
3701 cltv_expiry_delta: 0,
3702 htlc_minimum_msat: 0,
3703 htlc_maximum_msat: OptionalField::Present(50_000),
3705 fee_proportional_millionths: 0,
3706 excess_data: Vec::new()
3710 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3711 assert_eq!(route.paths.len(), 1);
3712 let mut total_amount_paid_msat = 0;
3713 for path in &route.paths {
3714 assert_eq!(path.len(), 2);
3715 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3716 total_amount_paid_msat += path.last().unwrap().fee_msat;
3718 assert_eq!(total_amount_paid_msat, 50_000);
3723 fn simple_mpp_route_test() {
3724 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3725 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3726 let scorer = test_utils::TestScorer::with_penalty(0);
3727 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3728 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3729 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3731 // We need a route consisting of 3 paths:
3732 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3733 // To achieve this, the amount being transferred should be around
3734 // the total capacity of these 3 paths.
3736 // First, we set limits on these (previously unlimited) channels.
3737 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3739 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3740 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3741 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3742 short_channel_id: 1,
3745 cltv_expiry_delta: 0,
3746 htlc_minimum_msat: 0,
3747 htlc_maximum_msat: OptionalField::Present(100_000),
3749 fee_proportional_millionths: 0,
3750 excess_data: Vec::new()
3752 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3753 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3754 short_channel_id: 3,
3757 cltv_expiry_delta: 0,
3758 htlc_minimum_msat: 0,
3759 htlc_maximum_msat: OptionalField::Present(50_000),
3761 fee_proportional_millionths: 0,
3762 excess_data: Vec::new()
3765 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3766 // (total limit 60).
3767 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3768 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3769 short_channel_id: 12,
3772 cltv_expiry_delta: 0,
3773 htlc_minimum_msat: 0,
3774 htlc_maximum_msat: OptionalField::Present(60_000),
3776 fee_proportional_millionths: 0,
3777 excess_data: Vec::new()
3779 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3780 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3781 short_channel_id: 13,
3784 cltv_expiry_delta: 0,
3785 htlc_minimum_msat: 0,
3786 htlc_maximum_msat: OptionalField::Present(60_000),
3788 fee_proportional_millionths: 0,
3789 excess_data: Vec::new()
3792 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3793 // (total capacity 180 sats).
3794 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3795 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3796 short_channel_id: 2,
3799 cltv_expiry_delta: 0,
3800 htlc_minimum_msat: 0,
3801 htlc_maximum_msat: OptionalField::Present(200_000),
3803 fee_proportional_millionths: 0,
3804 excess_data: Vec::new()
3806 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3807 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3808 short_channel_id: 4,
3811 cltv_expiry_delta: 0,
3812 htlc_minimum_msat: 0,
3813 htlc_maximum_msat: OptionalField::Present(180_000),
3815 fee_proportional_millionths: 0,
3816 excess_data: Vec::new()
3820 // Attempt to route more than available results in a failure.
3821 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3822 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3823 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3824 } else { panic!(); }
3828 // Now, attempt to route 250 sats (just a bit below the capacity).
3829 // Our algorithm should provide us with these 3 paths.
3830 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3831 assert_eq!(route.paths.len(), 3);
3832 let mut total_amount_paid_msat = 0;
3833 for path in &route.paths {
3834 assert_eq!(path.len(), 2);
3835 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3836 total_amount_paid_msat += path.last().unwrap().fee_msat;
3838 assert_eq!(total_amount_paid_msat, 250_000);
3842 // Attempt to route an exact amount is also fine
3843 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3844 assert_eq!(route.paths.len(), 3);
3845 let mut total_amount_paid_msat = 0;
3846 for path in &route.paths {
3847 assert_eq!(path.len(), 2);
3848 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3849 total_amount_paid_msat += path.last().unwrap().fee_msat;
3851 assert_eq!(total_amount_paid_msat, 290_000);
3856 fn long_mpp_route_test() {
3857 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3858 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3859 let scorer = test_utils::TestScorer::with_penalty(0);
3860 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3861 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3862 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3864 // We need a route consisting of 3 paths:
3865 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3866 // Note that these paths overlap (channels 5, 12, 13).
3867 // We will route 300 sats.
3868 // Each path will have 100 sats capacity, those channels which
3869 // are used twice will have 200 sats capacity.
3871 // Disable other potential paths.
3872 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3873 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3874 short_channel_id: 2,
3877 cltv_expiry_delta: 0,
3878 htlc_minimum_msat: 0,
3879 htlc_maximum_msat: OptionalField::Present(100_000),
3881 fee_proportional_millionths: 0,
3882 excess_data: Vec::new()
3884 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3885 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3886 short_channel_id: 7,
3889 cltv_expiry_delta: 0,
3890 htlc_minimum_msat: 0,
3891 htlc_maximum_msat: OptionalField::Present(100_000),
3893 fee_proportional_millionths: 0,
3894 excess_data: Vec::new()
3897 // Path via {node0, node2} is channels {1, 3, 5}.
3898 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3899 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3900 short_channel_id: 1,
3903 cltv_expiry_delta: 0,
3904 htlc_minimum_msat: 0,
3905 htlc_maximum_msat: OptionalField::Present(100_000),
3907 fee_proportional_millionths: 0,
3908 excess_data: Vec::new()
3910 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3911 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3912 short_channel_id: 3,
3915 cltv_expiry_delta: 0,
3916 htlc_minimum_msat: 0,
3917 htlc_maximum_msat: OptionalField::Present(100_000),
3919 fee_proportional_millionths: 0,
3920 excess_data: Vec::new()
3923 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3924 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3925 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3926 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3927 short_channel_id: 5,
3930 cltv_expiry_delta: 0,
3931 htlc_minimum_msat: 0,
3932 htlc_maximum_msat: OptionalField::Present(200_000),
3934 fee_proportional_millionths: 0,
3935 excess_data: Vec::new()
3938 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3939 // Add 100 sats to the capacities of {12, 13}, because these channels
3940 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3941 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3942 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3943 short_channel_id: 12,
3946 cltv_expiry_delta: 0,
3947 htlc_minimum_msat: 0,
3948 htlc_maximum_msat: OptionalField::Present(200_000),
3950 fee_proportional_millionths: 0,
3951 excess_data: Vec::new()
3953 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3954 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3955 short_channel_id: 13,
3958 cltv_expiry_delta: 0,
3959 htlc_minimum_msat: 0,
3960 htlc_maximum_msat: OptionalField::Present(200_000),
3962 fee_proportional_millionths: 0,
3963 excess_data: Vec::new()
3966 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3967 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3968 short_channel_id: 6,
3971 cltv_expiry_delta: 0,
3972 htlc_minimum_msat: 0,
3973 htlc_maximum_msat: OptionalField::Present(100_000),
3975 fee_proportional_millionths: 0,
3976 excess_data: Vec::new()
3978 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3979 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3980 short_channel_id: 11,
3983 cltv_expiry_delta: 0,
3984 htlc_minimum_msat: 0,
3985 htlc_maximum_msat: OptionalField::Present(100_000),
3987 fee_proportional_millionths: 0,
3988 excess_data: Vec::new()
3991 // Path via {node7, node2} is channels {12, 13, 5}.
3992 // We already limited them to 200 sats (they are used twice for 100 sats).
3993 // Nothing to do here.
3996 // Attempt to route more than available results in a failure.
3997 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3998 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3999 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4000 } else { panic!(); }
4004 // Now, attempt to route 300 sats (exact amount we can route).
4005 // Our algorithm should provide us with these 3 paths, 100 sats each.
4006 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4007 assert_eq!(route.paths.len(), 3);
4009 let mut total_amount_paid_msat = 0;
4010 for path in &route.paths {
4011 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4012 total_amount_paid_msat += path.last().unwrap().fee_msat;
4014 assert_eq!(total_amount_paid_msat, 300_000);
4020 fn mpp_cheaper_route_test() {
4021 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4022 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4023 let scorer = test_utils::TestScorer::with_penalty(0);
4024 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4025 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4026 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4028 // This test checks that if we have two cheaper paths and one more expensive path,
4029 // so that liquidity-wise any 2 of 3 combination is sufficient,
4030 // two cheaper paths will be taken.
4031 // These paths have equal available liquidity.
4033 // We need a combination of 3 paths:
4034 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4035 // Note that these paths overlap (channels 5, 12, 13).
4036 // Each path will have 100 sats capacity, those channels which
4037 // are used twice will have 200 sats capacity.
4039 // Disable other potential paths.
4040 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4041 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4042 short_channel_id: 2,
4045 cltv_expiry_delta: 0,
4046 htlc_minimum_msat: 0,
4047 htlc_maximum_msat: OptionalField::Present(100_000),
4049 fee_proportional_millionths: 0,
4050 excess_data: Vec::new()
4052 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4053 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4054 short_channel_id: 7,
4057 cltv_expiry_delta: 0,
4058 htlc_minimum_msat: 0,
4059 htlc_maximum_msat: OptionalField::Present(100_000),
4061 fee_proportional_millionths: 0,
4062 excess_data: Vec::new()
4065 // Path via {node0, node2} is channels {1, 3, 5}.
4066 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4067 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4068 short_channel_id: 1,
4071 cltv_expiry_delta: 0,
4072 htlc_minimum_msat: 0,
4073 htlc_maximum_msat: OptionalField::Present(100_000),
4075 fee_proportional_millionths: 0,
4076 excess_data: Vec::new()
4078 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4079 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4080 short_channel_id: 3,
4083 cltv_expiry_delta: 0,
4084 htlc_minimum_msat: 0,
4085 htlc_maximum_msat: OptionalField::Present(100_000),
4087 fee_proportional_millionths: 0,
4088 excess_data: Vec::new()
4091 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4092 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4093 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4094 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4095 short_channel_id: 5,
4098 cltv_expiry_delta: 0,
4099 htlc_minimum_msat: 0,
4100 htlc_maximum_msat: OptionalField::Present(200_000),
4102 fee_proportional_millionths: 0,
4103 excess_data: Vec::new()
4106 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4107 // Add 100 sats to the capacities of {12, 13}, because these channels
4108 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4109 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4110 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4111 short_channel_id: 12,
4114 cltv_expiry_delta: 0,
4115 htlc_minimum_msat: 0,
4116 htlc_maximum_msat: OptionalField::Present(200_000),
4118 fee_proportional_millionths: 0,
4119 excess_data: Vec::new()
4121 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4122 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4123 short_channel_id: 13,
4126 cltv_expiry_delta: 0,
4127 htlc_minimum_msat: 0,
4128 htlc_maximum_msat: OptionalField::Present(200_000),
4130 fee_proportional_millionths: 0,
4131 excess_data: Vec::new()
4134 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4135 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4136 short_channel_id: 6,
4139 cltv_expiry_delta: 0,
4140 htlc_minimum_msat: 0,
4141 htlc_maximum_msat: OptionalField::Present(100_000),
4142 fee_base_msat: 1_000,
4143 fee_proportional_millionths: 0,
4144 excess_data: Vec::new()
4146 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4147 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4148 short_channel_id: 11,
4151 cltv_expiry_delta: 0,
4152 htlc_minimum_msat: 0,
4153 htlc_maximum_msat: OptionalField::Present(100_000),
4155 fee_proportional_millionths: 0,
4156 excess_data: Vec::new()
4159 // Path via {node7, node2} is channels {12, 13, 5}.
4160 // We already limited them to 200 sats (they are used twice for 100 sats).
4161 // Nothing to do here.
4164 // Now, attempt to route 180 sats.
4165 // Our algorithm should provide us with these 2 paths.
4166 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4167 assert_eq!(route.paths.len(), 2);
4169 let mut total_value_transferred_msat = 0;
4170 let mut total_paid_msat = 0;
4171 for path in &route.paths {
4172 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4173 total_value_transferred_msat += path.last().unwrap().fee_msat;
4175 total_paid_msat += hop.fee_msat;
4178 // If we paid fee, this would be higher.
4179 assert_eq!(total_value_transferred_msat, 180_000);
4180 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4181 assert_eq!(total_fees_paid, 0);
4186 fn fees_on_mpp_route_test() {
4187 // This test makes sure that MPP algorithm properly takes into account
4188 // fees charged on the channels, by making the fees impactful:
4189 // if the fee is not properly accounted for, the behavior is different.
4190 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4191 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4192 let scorer = test_utils::TestScorer::with_penalty(0);
4193 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4194 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4195 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4197 // We need a route consisting of 2 paths:
4198 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4199 // We will route 200 sats, Each path will have 100 sats capacity.
4201 // This test is not particularly stable: e.g.,
4202 // there's a way to route via {node0, node2, node4}.
4203 // It works while pathfinding is deterministic, but can be broken otherwise.
4204 // It's fine to ignore this concern for now.
4206 // Disable other potential paths.
4207 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4208 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4209 short_channel_id: 2,
4212 cltv_expiry_delta: 0,
4213 htlc_minimum_msat: 0,
4214 htlc_maximum_msat: OptionalField::Present(100_000),
4216 fee_proportional_millionths: 0,
4217 excess_data: Vec::new()
4220 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4221 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4222 short_channel_id: 7,
4225 cltv_expiry_delta: 0,
4226 htlc_minimum_msat: 0,
4227 htlc_maximum_msat: OptionalField::Present(100_000),
4229 fee_proportional_millionths: 0,
4230 excess_data: Vec::new()
4233 // Path via {node0, node2} is channels {1, 3, 5}.
4234 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4235 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4236 short_channel_id: 1,
4239 cltv_expiry_delta: 0,
4240 htlc_minimum_msat: 0,
4241 htlc_maximum_msat: OptionalField::Present(100_000),
4243 fee_proportional_millionths: 0,
4244 excess_data: Vec::new()
4246 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4247 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4248 short_channel_id: 3,
4251 cltv_expiry_delta: 0,
4252 htlc_minimum_msat: 0,
4253 htlc_maximum_msat: OptionalField::Present(100_000),
4255 fee_proportional_millionths: 0,
4256 excess_data: Vec::new()
4259 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4260 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4261 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4262 short_channel_id: 5,
4265 cltv_expiry_delta: 0,
4266 htlc_minimum_msat: 0,
4267 htlc_maximum_msat: OptionalField::Present(100_000),
4269 fee_proportional_millionths: 0,
4270 excess_data: Vec::new()
4273 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4274 // All channels should be 100 sats capacity. But for the fee experiment,
4275 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4276 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4277 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4278 // so no matter how large are other channels,
4279 // the whole path will be limited by 100 sats with just these 2 conditions:
4280 // - channel 12 capacity is 250 sats
4281 // - fee for channel 6 is 150 sats
4282 // Let's test this by enforcing these 2 conditions and removing other limits.
4283 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4284 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4285 short_channel_id: 12,
4288 cltv_expiry_delta: 0,
4289 htlc_minimum_msat: 0,
4290 htlc_maximum_msat: OptionalField::Present(250_000),
4292 fee_proportional_millionths: 0,
4293 excess_data: Vec::new()
4295 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4296 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4297 short_channel_id: 13,
4300 cltv_expiry_delta: 0,
4301 htlc_minimum_msat: 0,
4302 htlc_maximum_msat: OptionalField::Absent,
4304 fee_proportional_millionths: 0,
4305 excess_data: Vec::new()
4308 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4309 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4310 short_channel_id: 6,
4313 cltv_expiry_delta: 0,
4314 htlc_minimum_msat: 0,
4315 htlc_maximum_msat: OptionalField::Absent,
4316 fee_base_msat: 150_000,
4317 fee_proportional_millionths: 0,
4318 excess_data: Vec::new()
4320 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4321 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4322 short_channel_id: 11,
4325 cltv_expiry_delta: 0,
4326 htlc_minimum_msat: 0,
4327 htlc_maximum_msat: OptionalField::Absent,
4329 fee_proportional_millionths: 0,
4330 excess_data: Vec::new()
4334 // Attempt to route more than available results in a failure.
4335 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4336 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4337 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4338 } else { panic!(); }
4342 // Now, attempt to route 200 sats (exact amount we can route).
4343 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4344 assert_eq!(route.paths.len(), 2);
4346 let mut total_amount_paid_msat = 0;
4347 for path in &route.paths {
4348 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4349 total_amount_paid_msat += path.last().unwrap().fee_msat;
4351 assert_eq!(total_amount_paid_msat, 200_000);
4352 assert_eq!(route.get_total_fees(), 150_000);
4357 fn mpp_with_last_hops() {
4358 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4359 // via a single last-hop route hint, we'd fail to route if we first collected routes
4360 // totaling close but not quite enough to fund the full payment.
4362 // This was because we considered last-hop hints to have exactly the sought payment amount
4363 // instead of the amount we were trying to collect, needlessly limiting our path searching
4364 // at the very first hop.
4366 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4367 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4368 // to only have the remaining to-collect amount in available liquidity.
4370 // This bug appeared in production in some specific channel configurations.
4371 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4372 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4373 let scorer = test_utils::TestScorer::with_penalty(0);
4374 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4375 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4376 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4377 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4378 src_node_id: nodes[2],
4379 short_channel_id: 42,
4380 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4381 cltv_expiry_delta: 42,
4382 htlc_minimum_msat: None,
4383 htlc_maximum_msat: None,
4386 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4387 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4388 // would first use the no-fee route and then fail to find a path along the second route as
4389 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4390 // under 5% of our payment amount.
4391 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4392 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4393 short_channel_id: 1,
4396 cltv_expiry_delta: (5 << 4) | 5,
4397 htlc_minimum_msat: 0,
4398 htlc_maximum_msat: OptionalField::Present(99_000),
4399 fee_base_msat: u32::max_value(),
4400 fee_proportional_millionths: u32::max_value(),
4401 excess_data: Vec::new()
4403 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4404 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4405 short_channel_id: 2,
4408 cltv_expiry_delta: (5 << 4) | 3,
4409 htlc_minimum_msat: 0,
4410 htlc_maximum_msat: OptionalField::Present(99_000),
4411 fee_base_msat: u32::max_value(),
4412 fee_proportional_millionths: u32::max_value(),
4413 excess_data: Vec::new()
4415 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4416 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4417 short_channel_id: 4,
4420 cltv_expiry_delta: (4 << 4) | 1,
4421 htlc_minimum_msat: 0,
4422 htlc_maximum_msat: OptionalField::Absent,
4424 fee_proportional_millionths: 0,
4425 excess_data: Vec::new()
4427 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4428 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4429 short_channel_id: 13,
4431 flags: 0|2, // Channel disabled
4432 cltv_expiry_delta: (13 << 4) | 1,
4433 htlc_minimum_msat: 0,
4434 htlc_maximum_msat: OptionalField::Absent,
4436 fee_proportional_millionths: 2000000,
4437 excess_data: Vec::new()
4440 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4442 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4443 assert_eq!(route.paths.len(), 2);
4444 // Paths are somewhat randomly ordered, but:
4445 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4446 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4447 assert_eq!(route.paths[0][0].short_channel_id, 2);
4448 assert_eq!(route.paths[0][0].fee_msat, 1);
4449 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4450 assert_eq!(route.paths[1][0].short_channel_id, 1);
4451 assert_eq!(route.paths[1][0].fee_msat, 0);
4452 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4453 assert_eq!(route.get_total_fees(), 1);
4454 assert_eq!(route.get_total_amount(), 100_000);
4458 fn drop_lowest_channel_mpp_route_test() {
4459 // This test checks that low-capacity channel is dropped when after
4460 // path finding we realize that we found more capacity than we need.
4461 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4462 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4463 let scorer = test_utils::TestScorer::with_penalty(0);
4464 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4465 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4466 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4468 // We need a route consisting of 3 paths:
4469 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4471 // The first and the second paths should be sufficient, but the third should be
4472 // cheaper, so that we select it but drop later.
4474 // First, we set limits on these (previously unlimited) channels.
4475 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4477 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4478 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4479 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4480 short_channel_id: 1,
4483 cltv_expiry_delta: 0,
4484 htlc_minimum_msat: 0,
4485 htlc_maximum_msat: OptionalField::Present(100_000),
4487 fee_proportional_millionths: 0,
4488 excess_data: Vec::new()
4490 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4491 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4492 short_channel_id: 3,
4495 cltv_expiry_delta: 0,
4496 htlc_minimum_msat: 0,
4497 htlc_maximum_msat: OptionalField::Present(50_000),
4499 fee_proportional_millionths: 0,
4500 excess_data: Vec::new()
4503 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4504 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4505 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4506 short_channel_id: 12,
4509 cltv_expiry_delta: 0,
4510 htlc_minimum_msat: 0,
4511 htlc_maximum_msat: OptionalField::Present(60_000),
4513 fee_proportional_millionths: 0,
4514 excess_data: Vec::new()
4516 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4517 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4518 short_channel_id: 13,
4521 cltv_expiry_delta: 0,
4522 htlc_minimum_msat: 0,
4523 htlc_maximum_msat: OptionalField::Present(60_000),
4525 fee_proportional_millionths: 0,
4526 excess_data: Vec::new()
4529 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4530 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4531 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4532 short_channel_id: 2,
4535 cltv_expiry_delta: 0,
4536 htlc_minimum_msat: 0,
4537 htlc_maximum_msat: OptionalField::Present(20_000),
4539 fee_proportional_millionths: 0,
4540 excess_data: Vec::new()
4542 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4543 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4544 short_channel_id: 4,
4547 cltv_expiry_delta: 0,
4548 htlc_minimum_msat: 0,
4549 htlc_maximum_msat: OptionalField::Present(20_000),
4551 fee_proportional_millionths: 0,
4552 excess_data: Vec::new()
4556 // Attempt to route more than available results in a failure.
4557 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4558 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4559 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4560 } else { panic!(); }
4564 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4565 // Our algorithm should provide us with these 3 paths.
4566 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4567 assert_eq!(route.paths.len(), 3);
4568 let mut total_amount_paid_msat = 0;
4569 for path in &route.paths {
4570 assert_eq!(path.len(), 2);
4571 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4572 total_amount_paid_msat += path.last().unwrap().fee_msat;
4574 assert_eq!(total_amount_paid_msat, 125_000);
4578 // Attempt to route without the last small cheap channel
4579 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4580 assert_eq!(route.paths.len(), 2);
4581 let mut total_amount_paid_msat = 0;
4582 for path in &route.paths {
4583 assert_eq!(path.len(), 2);
4584 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4585 total_amount_paid_msat += path.last().unwrap().fee_msat;
4587 assert_eq!(total_amount_paid_msat, 90_000);
4592 fn min_criteria_consistency() {
4593 // Test that we don't use an inconsistent metric between updating and walking nodes during
4594 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4595 // was updated with a different criterion from the heap sorting, resulting in loops in
4596 // calculated paths. We test for that specific case here.
4598 // We construct a network that looks like this:
4600 // node2 -1(3)2- node3
4604 // node1 -1(5)2- node4 -1(1)2- node6
4610 // We create a loop on the side of our real path - our destination is node 6, with a
4611 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4612 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4613 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4614 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4615 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4616 // "previous hop" being set to node 3, creating a loop in the path.
4617 let secp_ctx = Secp256k1::new();
4618 let logger = Arc::new(test_utils::TestLogger::new());
4619 let network = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
4620 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network), None, Arc::clone(&logger));
4621 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4622 let scorer = test_utils::TestScorer::with_penalty(0);
4623 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4624 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4625 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4627 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4628 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4629 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4630 short_channel_id: 6,
4633 cltv_expiry_delta: (6 << 4) | 0,
4634 htlc_minimum_msat: 0,
4635 htlc_maximum_msat: OptionalField::Absent,
4637 fee_proportional_millionths: 0,
4638 excess_data: Vec::new()
4640 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4642 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4643 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4644 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4645 short_channel_id: 5,
4648 cltv_expiry_delta: (5 << 4) | 0,
4649 htlc_minimum_msat: 0,
4650 htlc_maximum_msat: OptionalField::Absent,
4652 fee_proportional_millionths: 0,
4653 excess_data: Vec::new()
4655 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4657 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4658 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4660 short_channel_id: 4,
4663 cltv_expiry_delta: (4 << 4) | 0,
4664 htlc_minimum_msat: 0,
4665 htlc_maximum_msat: OptionalField::Absent,
4667 fee_proportional_millionths: 0,
4668 excess_data: Vec::new()
4670 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4672 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4673 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4674 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4675 short_channel_id: 3,
4678 cltv_expiry_delta: (3 << 4) | 0,
4679 htlc_minimum_msat: 0,
4680 htlc_maximum_msat: OptionalField::Absent,
4682 fee_proportional_millionths: 0,
4683 excess_data: Vec::new()
4685 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4687 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4688 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4689 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4690 short_channel_id: 2,
4693 cltv_expiry_delta: (2 << 4) | 0,
4694 htlc_minimum_msat: 0,
4695 htlc_maximum_msat: OptionalField::Absent,
4697 fee_proportional_millionths: 0,
4698 excess_data: Vec::new()
4701 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4702 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4703 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4704 short_channel_id: 1,
4707 cltv_expiry_delta: (1 << 4) | 0,
4708 htlc_minimum_msat: 100,
4709 htlc_maximum_msat: OptionalField::Absent,
4711 fee_proportional_millionths: 0,
4712 excess_data: Vec::new()
4714 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4717 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4718 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4719 assert_eq!(route.paths.len(), 1);
4720 assert_eq!(route.paths[0].len(), 3);
4722 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4723 assert_eq!(route.paths[0][0].short_channel_id, 6);
4724 assert_eq!(route.paths[0][0].fee_msat, 100);
4725 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
4726 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4727 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4729 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4730 assert_eq!(route.paths[0][1].short_channel_id, 5);
4731 assert_eq!(route.paths[0][1].fee_msat, 0);
4732 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
4733 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4734 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4736 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4737 assert_eq!(route.paths[0][2].short_channel_id, 1);
4738 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4739 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4740 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4741 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4747 fn exact_fee_liquidity_limit() {
4748 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4749 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4750 // we calculated fees on a higher value, resulting in us ignoring such paths.
4751 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4752 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4753 let scorer = test_utils::TestScorer::with_penalty(0);
4754 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4755 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4756 let payment_params = PaymentParameters::from_node_id(nodes[2]);
4758 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4760 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4761 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4762 short_channel_id: 2,
4765 cltv_expiry_delta: 0,
4766 htlc_minimum_msat: 0,
4767 htlc_maximum_msat: OptionalField::Present(85_000),
4769 fee_proportional_millionths: 0,
4770 excess_data: Vec::new()
4773 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4774 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4775 short_channel_id: 12,
4778 cltv_expiry_delta: (4 << 4) | 1,
4779 htlc_minimum_msat: 0,
4780 htlc_maximum_msat: OptionalField::Present(270_000),
4782 fee_proportional_millionths: 1000000,
4783 excess_data: Vec::new()
4787 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4788 // 200% fee charged channel 13 in the 1-to-2 direction.
4789 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4790 assert_eq!(route.paths.len(), 1);
4791 assert_eq!(route.paths[0].len(), 2);
4793 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4794 assert_eq!(route.paths[0][0].short_channel_id, 12);
4795 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4796 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4797 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4798 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4800 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4801 assert_eq!(route.paths[0][1].short_channel_id, 13);
4802 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4803 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4804 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4805 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4810 fn htlc_max_reduction_below_min() {
4811 // Test that if, while walking the graph, we reduce the value being sent to meet an
4812 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4813 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4814 // resulting in us thinking there is no possible path, even if other paths exist.
4815 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4816 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4817 let scorer = test_utils::TestScorer::with_penalty(0);
4818 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4819 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4820 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4822 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4823 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4824 // then try to send 90_000.
4825 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4826 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4827 short_channel_id: 2,
4830 cltv_expiry_delta: 0,
4831 htlc_minimum_msat: 0,
4832 htlc_maximum_msat: OptionalField::Present(80_000),
4834 fee_proportional_millionths: 0,
4835 excess_data: Vec::new()
4837 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4838 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4839 short_channel_id: 4,
4842 cltv_expiry_delta: (4 << 4) | 1,
4843 htlc_minimum_msat: 90_000,
4844 htlc_maximum_msat: OptionalField::Absent,
4846 fee_proportional_millionths: 0,
4847 excess_data: Vec::new()
4851 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
4852 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
4853 // expensive) channels 12-13 path.
4854 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4855 assert_eq!(route.paths.len(), 1);
4856 assert_eq!(route.paths[0].len(), 2);
4858 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4859 assert_eq!(route.paths[0][0].short_channel_id, 12);
4860 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4861 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4862 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4863 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4865 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4866 assert_eq!(route.paths[0][1].short_channel_id, 13);
4867 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4868 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4869 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
4870 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4875 fn multiple_direct_first_hops() {
4876 // Previously we'd only ever considered one first hop path per counterparty.
4877 // However, as we don't restrict users to one channel per peer, we really need to support
4878 // looking at all first hop paths.
4879 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
4880 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
4881 // route over multiple channels with the same first hop.
4882 let secp_ctx = Secp256k1::new();
4883 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4884 let logger = Arc::new(test_utils::TestLogger::new());
4885 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
4886 let scorer = test_utils::TestScorer::with_penalty(0);
4887 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
4888 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4889 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4892 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4893 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
4894 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
4895 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4896 assert_eq!(route.paths.len(), 1);
4897 assert_eq!(route.paths[0].len(), 1);
4899 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4900 assert_eq!(route.paths[0][0].short_channel_id, 3);
4901 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4904 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4905 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4906 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4907 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4908 assert_eq!(route.paths.len(), 2);
4909 assert_eq!(route.paths[0].len(), 1);
4910 assert_eq!(route.paths[1].len(), 1);
4912 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4913 assert_eq!(route.paths[0][0].short_channel_id, 3);
4914 assert_eq!(route.paths[0][0].fee_msat, 50_000);
4916 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
4917 assert_eq!(route.paths[1][0].short_channel_id, 2);
4918 assert_eq!(route.paths[1][0].fee_msat, 50_000);
4922 // If we have a bunch of outbound channels to the same node, where most are not
4923 // sufficient to pay the full payment, but one is, we should default to just using the
4924 // one single channel that has sufficient balance, avoiding MPP.
4926 // If we have several options above the 3xpayment value threshold, we should pick the
4927 // smallest of them, avoiding further fragmenting our available outbound balance to
4929 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4930 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4931 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4932 &get_channel_details(Some(5), nodes[0], InitFeatures::known(), 50_000),
4933 &get_channel_details(Some(6), nodes[0], InitFeatures::known(), 300_000),
4934 &get_channel_details(Some(7), nodes[0], InitFeatures::known(), 50_000),
4935 &get_channel_details(Some(8), nodes[0], InitFeatures::known(), 50_000),
4936 &get_channel_details(Some(9), nodes[0], InitFeatures::known(), 50_000),
4937 &get_channel_details(Some(4), nodes[0], InitFeatures::known(), 1_000_000),
4938 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4939 assert_eq!(route.paths.len(), 1);
4940 assert_eq!(route.paths[0].len(), 1);
4942 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4943 assert_eq!(route.paths[0][0].short_channel_id, 6);
4944 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4949 fn prefers_shorter_route_with_higher_fees() {
4950 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4951 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4952 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
4954 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
4955 let scorer = test_utils::TestScorer::with_penalty(0);
4956 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4957 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4958 let route = get_route(
4959 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
4960 Arc::clone(&logger), &scorer, &random_seed_bytes
4962 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4964 assert_eq!(route.get_total_fees(), 100);
4965 assert_eq!(route.get_total_amount(), 100);
4966 assert_eq!(path, vec![2, 4, 6, 11, 8]);
4968 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
4969 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
4970 let scorer = test_utils::TestScorer::with_penalty(100);
4971 let route = get_route(
4972 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
4973 Arc::clone(&logger), &scorer, &random_seed_bytes
4975 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4977 assert_eq!(route.get_total_fees(), 300);
4978 assert_eq!(route.get_total_amount(), 100);
4979 assert_eq!(path, vec![2, 4, 7, 10]);
4982 struct BadChannelScorer {
4983 short_channel_id: u64,
4987 impl Writeable for BadChannelScorer {
4988 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
4990 impl Score for BadChannelScorer {
4991 fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, _target: &NodeId) -> u64 {
4992 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
4995 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
4996 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
4999 struct BadNodeScorer {
5004 impl Writeable for BadNodeScorer {
5005 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5008 impl Score for BadNodeScorer {
5009 fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, target: &NodeId) -> u64 {
5010 if *target == self.node_id { u64::max_value() } else { 0 }
5013 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5014 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5018 fn avoids_routing_through_bad_channels_and_nodes() {
5019 let (secp_ctx, network, _, _, logger) = build_graph();
5020 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5021 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5022 let network_graph = network.read_only();
5024 // A path to nodes[6] exists when no penalties are applied to any channel.
5025 let scorer = test_utils::TestScorer::with_penalty(0);
5026 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5027 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5028 let route = get_route(
5029 &our_id, &payment_params, &network_graph, None, 100, 42,
5030 Arc::clone(&logger), &scorer, &random_seed_bytes
5032 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5034 assert_eq!(route.get_total_fees(), 100);
5035 assert_eq!(route.get_total_amount(), 100);
5036 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5038 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5039 let scorer = BadChannelScorer { short_channel_id: 6 };
5040 let route = get_route(
5041 &our_id, &payment_params, &network_graph, None, 100, 42,
5042 Arc::clone(&logger), &scorer, &random_seed_bytes
5044 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5046 assert_eq!(route.get_total_fees(), 300);
5047 assert_eq!(route.get_total_amount(), 100);
5048 assert_eq!(path, vec![2, 4, 7, 10]);
5050 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5051 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5053 &our_id, &payment_params, &network_graph, None, 100, 42,
5054 Arc::clone(&logger), &scorer, &random_seed_bytes
5056 Err(LightningError { err, .. } ) => {
5057 assert_eq!(err, "Failed to find a path to the given destination");
5059 Ok(_) => panic!("Expected error"),
5064 fn total_fees_single_path() {
5068 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5069 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5070 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5073 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5074 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5075 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5078 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5079 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5080 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5083 payment_params: None,
5086 assert_eq!(route.get_total_fees(), 250);
5087 assert_eq!(route.get_total_amount(), 225);
5091 fn total_fees_multi_path() {
5095 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5096 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5097 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5100 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5101 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5102 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5106 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5107 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5108 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5111 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5112 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5113 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5116 payment_params: None,
5119 assert_eq!(route.get_total_fees(), 200);
5120 assert_eq!(route.get_total_amount(), 300);
5124 fn total_empty_route_no_panic() {
5125 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5126 // would both panic if the route was completely empty. We test to ensure they return 0
5127 // here, even though its somewhat nonsensical as a route.
5128 let route = Route { paths: Vec::new(), payment_params: None };
5130 assert_eq!(route.get_total_fees(), 0);
5131 assert_eq!(route.get_total_amount(), 0);
5135 fn limits_total_cltv_delta() {
5136 let (secp_ctx, network, _, _, logger) = build_graph();
5137 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5138 let network_graph = network.read_only();
5140 let scorer = test_utils::TestScorer::with_penalty(0);
5142 // Make sure that generally there is at least one route available
5143 let feasible_max_total_cltv_delta = 1008;
5144 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5145 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5146 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5147 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5148 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5149 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5150 assert_ne!(path.len(), 0);
5152 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5153 let fail_max_total_cltv_delta = 23;
5154 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5155 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5156 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5158 Err(LightningError { err, .. } ) => {
5159 assert_eq!(err, "Failed to find a path to the given destination");
5161 Ok(_) => panic!("Expected error"),
5166 fn adds_and_limits_cltv_offset() {
5167 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5168 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5170 let scorer = test_utils::TestScorer::with_penalty(0);
5172 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5173 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5174 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5175 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5176 assert_eq!(route.paths.len(), 1);
5178 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5180 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5181 let mut route_default = route.clone();
5182 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5183 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5184 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5185 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5186 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5188 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5189 let mut route_limited = route.clone();
5190 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5191 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5192 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5193 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5194 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5198 fn adds_plausible_cltv_offset() {
5199 let (secp_ctx, network, _, _, logger) = build_graph();
5200 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5201 let network_graph = network.read_only();
5202 let network_nodes = network_graph.nodes();
5203 let network_channels = network_graph.channels();
5204 let scorer = test_utils::TestScorer::with_penalty(0);
5205 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5206 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5207 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5209 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5210 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5211 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5213 let mut path_plausibility = vec![];
5215 for p in route.paths {
5216 // 1. Select random observation point
5217 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5218 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5220 prng.process_in_place(&mut random_bytes);
5221 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5222 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5224 // 2. Calculate what CLTV expiry delta we would observe there
5225 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5227 // 3. Starting from the observation point, find candidate paths
5228 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5229 candidates.push_back((observation_point, vec![]));
5231 let mut found_plausible_candidate = false;
5233 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5234 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5235 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5236 found_plausible_candidate = true;
5237 break 'candidate_loop;
5241 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5242 for channel_id in &cur_node.channels {
5243 if let Some(channel_info) = network_channels.get(&channel_id) {
5244 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5245 if let Some(channel_update_info) = dir_info.direction() {
5246 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5247 if cur_path_cltv_deltas.iter().sum::<u32>()
5248 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5249 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5250 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5251 candidates.push_back((*next_id, new_path_cltv_deltas));
5260 path_plausibility.push(found_plausible_candidate);
5262 assert!(path_plausibility.iter().all(|x| *x));
5265 #[cfg(not(feature = "no-std"))]
5266 pub(super) fn random_init_seed() -> u64 {
5267 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5268 use core::hash::{BuildHasher, Hasher};
5269 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5270 println!("Using seed of {}", seed);
5273 #[cfg(not(feature = "no-std"))]
5274 use util::ser::Readable;
5277 #[cfg(not(feature = "no-std"))]
5278 fn generate_routes() {
5279 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5281 let mut d = match super::test_utils::get_route_file() {
5288 let graph = NetworkGraph::read(&mut d).unwrap();
5289 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5290 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5292 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5293 let mut seed = random_init_seed() as usize;
5294 let nodes = graph.read_only().nodes().clone();
5295 'load_endpoints: for _ in 0..10 {
5297 seed = seed.overflowing_mul(0xdeadbeef).0;
5298 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5299 seed = seed.overflowing_mul(0xdeadbeef).0;
5300 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5301 let payment_params = PaymentParameters::from_node_id(dst);
5302 let amt = seed as u64 % 200_000_000;
5303 let params = ProbabilisticScoringParameters::default();
5304 let scorer = ProbabilisticScorer::new(params, &graph);
5305 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5306 continue 'load_endpoints;
5313 #[cfg(not(feature = "no-std"))]
5314 fn generate_routes_mpp() {
5315 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5317 let mut d = match super::test_utils::get_route_file() {
5324 let graph = NetworkGraph::read(&mut d).unwrap();
5325 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5326 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5328 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5329 let mut seed = random_init_seed() as usize;
5330 let nodes = graph.read_only().nodes().clone();
5331 'load_endpoints: for _ in 0..10 {
5333 seed = seed.overflowing_mul(0xdeadbeef).0;
5334 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5335 seed = seed.overflowing_mul(0xdeadbeef).0;
5336 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5337 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5338 let amt = seed as u64 % 200_000_000;
5339 let params = ProbabilisticScoringParameters::default();
5340 let scorer = ProbabilisticScorer::new(params, &graph);
5341 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5342 continue 'load_endpoints;
5349 #[cfg(all(test, not(feature = "no-std")))]
5350 pub(crate) mod test_utils {
5352 /// Tries to open a network graph file, or panics with a URL to fetch it.
5353 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5354 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5355 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5356 .or_else(|_| { // Fall back to guessing based on the binary location
5357 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5358 let mut path = std::env::current_exe().unwrap();
5359 path.pop(); // lightning-...
5361 path.pop(); // debug
5362 path.pop(); // target
5363 path.push("lightning");
5364 path.push("net_graph-2021-05-31.bin");
5365 eprintln!("{}", path.to_str().unwrap());
5368 .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");
5369 #[cfg(require_route_graph_test)]
5370 return Ok(res.unwrap());
5371 #[cfg(not(require_route_graph_test))]
5376 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5379 use bitcoin::hashes::Hash;
5380 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5381 use chain::transaction::OutPoint;
5382 use chain::keysinterface::{KeysManager,KeysInterface};
5383 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5384 use ln::features::{InitFeatures, InvoiceFeatures};
5385 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters, Scorer};
5386 use util::logger::{Logger, Record};
5390 struct DummyLogger {}
5391 impl Logger for DummyLogger {
5392 fn log(&self, _record: &Record) {}
5395 fn read_network_graph() -> NetworkGraph {
5396 let mut d = test_utils::get_route_file().unwrap();
5397 NetworkGraph::read(&mut d).unwrap()
5400 fn payer_pubkey() -> PublicKey {
5401 let secp_ctx = Secp256k1::new();
5402 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5406 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5408 channel_id: [0; 32],
5409 counterparty: ChannelCounterparty {
5410 features: InitFeatures::known(),
5412 unspendable_punishment_reserve: 0,
5413 forwarding_info: None,
5415 funding_txo: Some(OutPoint {
5416 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5418 short_channel_id: Some(1),
5419 inbound_scid_alias: None,
5420 channel_value_satoshis: 10_000_000,
5422 balance_msat: 10_000_000,
5423 outbound_capacity_msat: 10_000_000,
5424 inbound_capacity_msat: 0,
5425 unspendable_punishment_reserve: None,
5426 confirmations_required: None,
5427 force_close_spend_delay: None,
5429 is_funding_locked: true,
5436 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5437 let network_graph = read_network_graph();
5438 let scorer = FixedPenaltyScorer::with_penalty(0);
5439 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5443 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5444 let network_graph = read_network_graph();
5445 let scorer = FixedPenaltyScorer::with_penalty(0);
5446 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5450 fn generate_routes_with_default_scorer(bench: &mut Bencher) {
5451 let network_graph = read_network_graph();
5452 let scorer = Scorer::default();
5453 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5457 fn generate_mpp_routes_with_default_scorer(bench: &mut Bencher) {
5458 let network_graph = read_network_graph();
5459 let scorer = Scorer::default();
5460 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5464 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5465 let network_graph = read_network_graph();
5466 let params = ProbabilisticScoringParameters::default();
5467 let scorer = ProbabilisticScorer::new(params, &network_graph);
5468 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5472 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5473 let network_graph = read_network_graph();
5474 let params = ProbabilisticScoringParameters::default();
5475 let scorer = ProbabilisticScorer::new(params, &network_graph);
5476 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5479 fn generate_routes<S: Score>(
5480 bench: &mut Bencher, graph: &NetworkGraph, mut scorer: S, features: InvoiceFeatures
5482 let nodes = graph.read_only().nodes().clone();
5483 let payer = payer_pubkey();
5484 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5485 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5487 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5488 let mut routes = Vec::new();
5489 let mut route_endpoints = Vec::new();
5490 let mut seed: usize = 0xdeadbeef;
5491 'load_endpoints: for _ in 0..150 {
5494 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5496 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5497 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5498 let first_hop = first_hop(src);
5499 let amt = seed as u64 % 1_000_000;
5500 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5502 route_endpoints.push((first_hop, params, amt));
5503 continue 'load_endpoints;
5508 // ...and seed the scorer with success and failure data...
5509 for route in routes {
5510 let amount = route.get_total_amount();
5511 if amount < 250_000 {
5512 for path in route.paths {
5513 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5515 } else if amount > 750_000 {
5516 for path in route.paths {
5517 let short_channel_id = path[path.len() / 2].short_channel_id;
5518 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5523 // Because we've changed channel scores, its possible we'll take different routes to the
5524 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5525 // requires a too-high CLTV delta.
5526 route_endpoints.retain(|(first_hop, params, amt)| {
5527 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5529 route_endpoints.truncate(100);
5530 assert_eq!(route_endpoints.len(), 100);
5532 // ...then benchmark finding paths between the nodes we learned.
5535 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5536 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());