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_path_penalty_msat(&self) -> u64 {
499 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
502 fn get_total_fee_paid_msat(&self) -> u64 {
503 if self.hops.len() < 1 {
507 // Can't use next_hops_fee_msat because it gets outdated.
508 for (i, (hop, _)) in self.hops.iter().enumerate() {
509 if i != self.hops.len() - 1 {
510 result += hop.fee_msat;
516 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
517 // to change fees may result in an inconsistency.
519 // Sometimes we call this function right after constructing a path which is inconsistent in
520 // that it the value being transferred has decreased while we were doing path finding, leading
521 // to the fees being paid not lining up with the actual limits.
523 // Note that this function is not aware of the available_liquidity limit, and thus does not
524 // support increasing the value being transferred.
525 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
526 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
528 let mut total_fee_paid_msat = 0 as u64;
529 for i in (0..self.hops.len()).rev() {
530 let last_hop = i == self.hops.len() - 1;
532 // For non-last-hop, this value will represent the fees paid on the current hop. It
533 // will consist of the fees for the use of the next hop, and extra fees to match
534 // htlc_minimum_msat of the current channel. Last hop is handled separately.
535 let mut cur_hop_fees_msat = 0;
537 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
540 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
541 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
542 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
543 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
544 // set it too high just to maliciously take more fees by exploiting this
545 // match htlc_minimum_msat logic.
546 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
547 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
548 // Note that there is a risk that *previous hops* (those closer to us, as we go
549 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
551 // This might make us end up with a broken route, although this should be super-rare
552 // in practice, both because of how healthy channels look like, and how we pick
553 // channels in add_entry.
554 // Also, this can't be exploited more heavily than *announce a free path and fail
556 cur_hop_transferred_amount_msat += extra_fees_msat;
557 total_fee_paid_msat += extra_fees_msat;
558 cur_hop_fees_msat += extra_fees_msat;
562 // Final hop is a special case: it usually has just value_msat (by design), but also
563 // it still could overpay for the htlc_minimum_msat.
564 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
566 // Propagate updated fees for the use of the channels to one hop back, where they
567 // will be actually paid (fee_msat). The last hop is handled above separately.
568 cur_hop.fee_msat = cur_hop_fees_msat;
571 // Fee for the use of the current hop which will be deducted on the previous hop.
572 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
573 // this channel is free for us.
575 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
576 cur_hop.hop_use_fee_msat = new_fee;
577 total_fee_paid_msat += new_fee;
579 // It should not be possible because this function is called only to reduce the
580 // value. In that case, compute_fee was already called with the same fees for
581 // larger amount and there was no overflow.
589 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
590 let proportional_fee_millions =
591 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
592 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
593 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
597 // This function may be (indirectly) called without any verification,
598 // with channel_fees provided by a caller. We should handle it gracefully.
603 /// Finds a route from us (payer) to the given target node (payee).
605 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
606 /// Without this, MPP will only be used if the payee's features are available in the network graph.
608 /// Private routing paths between a public node and the target may be included in `params.payee`.
610 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
611 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of our local
612 /// channels from [`NetworkGraph`] will be ignored, and only those in `first_hops` will be used.
614 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
615 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
616 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
620 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
621 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
626 /// Panics if first_hops contains channels without short_channel_ids;
627 /// [`ChannelManager::list_usable_channels`] will never include such channels.
629 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
630 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
631 pub fn find_route<L: Deref, S: Score>(
632 our_node_pubkey: &PublicKey, route_params: &RouteParameters, network: &NetworkGraph,
633 first_hops: Option<&[&ChannelDetails]>, logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
634 ) -> Result<Route, LightningError>
635 where L::Target: Logger {
636 let network_graph = network.read_only();
638 our_node_pubkey, &route_params.payment_params, &network_graph, first_hops, route_params.final_value_msat,
639 route_params.final_cltv_expiry_delta, logger, scorer, random_seed_bytes
642 add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
645 Err(err) => Err(err),
649 pub(crate) fn get_route<L: Deref, S: Score>(
650 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
651 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
652 logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
653 ) -> Result<Route, LightningError>
654 where L::Target: Logger {
655 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
656 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
658 if payee_node_id == our_node_id {
659 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
662 if final_value_msat > MAX_VALUE_MSAT {
663 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
666 if final_value_msat == 0 {
667 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
670 for route in payment_params.route_hints.iter() {
671 for hop in &route.0 {
672 if hop.src_node_id == payment_params.payee_pubkey {
673 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
677 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
678 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});
681 // The general routing idea is the following:
682 // 1. Fill first/last hops communicated by the caller.
683 // 2. Attempt to construct a path from payer to payee for transferring
684 // any ~sufficient (described later) value.
685 // If succeed, remember which channels were used and how much liquidity they have available,
686 // so that future paths don't rely on the same liquidity.
687 // 3. Proceed to the next step if:
688 // - we hit the recommended target value;
689 // - OR if we could not construct a new path. Any next attempt will fail too.
690 // Otherwise, repeat step 2.
691 // 4. See if we managed to collect paths which aggregately are able to transfer target value
692 // (not recommended value).
693 // 5. If yes, proceed. If not, fail routing.
694 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
695 // 7. Of all the found paths, select only those with the lowest total fee.
696 // 8. The last path in every selected route is likely to be more than we need.
697 // Reduce its value-to-transfer and recompute fees.
698 // 9. Choose the best route by the lowest total fee.
700 // As for the actual search algorithm,
701 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
702 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
704 // We are not a faithful Dijkstra's implementation because we can change values which impact
705 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
706 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
707 // the value we are currently attempting to send over a path, we simply reduce the value being
708 // sent along the path for any hops after that channel. This may imply that later fees (which
709 // we've already tabulated) are lower because a smaller value is passing through the channels
710 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
711 // channels which were selected earlier (and which may still be used for other paths without a
712 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
715 // One potentially problematic case for this algorithm would be if there are many
716 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
717 // graph walking), we may never find a path which is not liquidity-limited and has lower
718 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
719 // Because we only consider paths with at least 5% of the total value being sent, the damage
720 // from such a case should be limited, however this could be further reduced in the future by
721 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
722 // limits for the purposes of fee calculation.
724 // Alternatively, we could store more detailed path information in the heap (targets, below)
725 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
726 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
727 // and practically (as we would need to store dynamically-allocated path information in heap
728 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
729 // results of such an algorithm would likely be biased towards lower-value paths.
731 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
732 // outside of our current search value, running a path search more times to gather candidate
733 // paths at different values. While this may be acceptable, further path searches may increase
734 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
735 // graph for candidate paths, calculating the maximum value which can realistically be sent at
736 // the same time, remaining generic across different payment values.
738 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
739 // to use as the A* heuristic beyond just the cost to get one node further than the current
742 let network_channels = network_graph.channels();
743 let network_nodes = network_graph.nodes();
745 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
746 // it. If the payee supports it they're supposed to include it in the invoice, so that should
748 let allow_mpp = if let Some(features) = &payment_params.features {
749 features.supports_basic_mpp()
750 } else if let Some(node) = network_nodes.get(&payee_node_id) {
751 if let Some(node_info) = node.announcement_info.as_ref() {
752 node_info.features.supports_basic_mpp()
755 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
756 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
757 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
760 // Prepare the data we'll use for payee-to-payer search by
761 // inserting first hops suggested by the caller as targets.
762 // Our search will then attempt to reach them while traversing from the payee node.
763 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
764 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
765 if let Some(hops) = first_hops {
767 if chan.short_channel_id.is_none() {
768 panic!("first_hops should be filled in with usable channels, not pending ones");
770 if chan.counterparty.node_id == *our_node_pubkey {
771 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
774 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
775 .or_insert(Vec::new())
778 if first_hop_targets.is_empty() {
779 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
783 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
784 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
785 // adding duplicate entries when we find a better path to a given node.
786 let mut targets = BinaryHeap::new();
788 // Map from node_id to information about the best current path to that node, including feerate
790 let mut dist = HashMap::with_capacity(network_nodes.len());
792 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
793 // indicating that we may wish to try again with a higher value, potentially paying to meet an
794 // htlc_minimum with extra fees while still finding a cheaper path.
795 let mut hit_minimum_limit;
797 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
798 // We start with a path_value of the exact amount we want, and if that generates a route we may
799 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
800 // amount we want in total across paths, selecting the best subset at the end.
801 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
802 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
803 let mut path_value_msat = final_value_msat;
805 // We don't want multiple paths (as per MPP) share liquidity of the same channels.
806 // This map allows paths to be aware of the channel use by other paths in the same call.
807 // This would help to make a better path finding decisions and not "overbook" channels.
808 // It is unaware of the directions (except for `outbound_capacity_msat` in `first_hops`).
809 let mut bookkept_channels_liquidity_available_msat = HashMap::with_capacity(network_nodes.len());
811 // Keeping track of how much value we already collected across other paths. Helps to decide:
812 // - how much a new path should be transferring (upper bound);
813 // - whether a channel should be disregarded because
814 // it's available liquidity is too small comparing to how much more we need to collect;
815 // - when we want to stop looking for new paths.
816 let mut already_collected_value_msat = 0;
818 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
820 macro_rules! add_entry {
821 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
822 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
823 // since that value has to be transferred over this channel.
824 // Returns whether this channel caused an update to `targets`.
825 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
826 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
827 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr ) => { {
828 // We "return" whether we updated the path at the end, via this:
829 let mut did_add_update_path_to_src_node = false;
830 // Channels to self should not be used. This is more of belt-and-suspenders, because in
831 // practice these cases should be caught earlier:
832 // - for regular channels at channel announcement (TODO)
833 // - for first and last hops early in get_route
834 if $src_node_id != $dest_node_id {
835 let short_channel_id = $candidate.short_channel_id();
836 let available_liquidity_msat = bookkept_channels_liquidity_available_msat
837 .entry(short_channel_id)
838 .or_insert_with(|| $candidate.effective_capacity().as_msat());
840 // It is tricky to substract $next_hops_fee_msat from available liquidity here.
841 // It may be misleading because we might later choose to reduce the value transferred
842 // over these channels, and the channel which was insufficient might become sufficient.
843 // Worst case: we drop a good channel here because it can't cover the high following
844 // fees caused by one expensive channel, but then this channel could have been used
845 // if the amount being transferred over this path is lower.
846 // We do this for now, but this is a subject for removal.
847 if let Some(available_value_contribution_msat) = available_liquidity_msat.checked_sub($next_hops_fee_msat) {
849 // Routing Fragmentation Mitigation heuristic:
851 // Routing fragmentation across many payment paths increases the overall routing
852 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
853 // Taking too many smaller paths also increases the chance of payment failure.
854 // Thus to avoid this effect, we require from our collected links to provide
855 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
857 // This requirement is currently 5% of the remaining-to-be-collected value.
858 // This means as we successfully advance in our collection,
859 // the absolute liquidity contribution is lowered,
860 // thus increasing the number of potential channels to be selected.
862 // Derive the minimal liquidity contribution with a ratio of 20 (5%, rounded up)
863 // or 100% if we're not allowed to do multipath payments.
864 let minimal_value_contribution_msat: u64 = if allow_mpp {
865 (recommended_value_msat - already_collected_value_msat + 19) / 20
869 // Verify the liquidity offered by this channel complies to the minimal contribution.
870 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
872 // Do not consider candidates that exceed the maximum total cltv expiry limit.
873 // In order to already account for some of the privacy enhancing random CLTV
874 // expiry delta offset we add on top later, we subtract a rough estimate
875 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
876 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
877 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
878 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
879 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
880 .checked_add($candidate.cltv_expiry_delta())
881 .unwrap_or(u32::max_value());
882 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
884 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
885 // Includes paying fees for the use of the following channels.
886 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
887 Some(result) => result,
888 // Can't overflow due to how the values were computed right above.
889 None => unreachable!(),
891 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
892 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
893 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
895 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
896 // bother considering this channel.
897 // Since we're choosing amount_to_transfer_over_msat as maximum possible, it can
898 // be only reduced later (not increased), so this channel should just be skipped
899 // as not sufficient.
900 if !over_path_minimum_msat && doesnt_exceed_cltv_delta_limit {
901 hit_minimum_limit = true;
902 } else if contributes_sufficient_value && doesnt_exceed_cltv_delta_limit {
903 // Note that low contribution here (limited by available_liquidity_msat)
904 // might violate htlc_minimum_msat on the hops which are next along the
905 // payment path (upstream to the payee). To avoid that, we recompute
906 // path fees knowing the final path contribution after constructing it.
907 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
908 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
909 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
910 .unwrap_or_else(|| u64::max_value());
911 let hm_entry = dist.entry($src_node_id);
912 let old_entry = hm_entry.or_insert_with(|| {
913 // If there was previously no known way to access the source node
914 // (recall it goes payee-to-payer) of short_channel_id, first add a
915 // semi-dummy record just to compute the fees to reach the source node.
916 // This will affect our decision on selecting short_channel_id
917 // as a way to reach the $dest_node_id.
918 let mut fee_base_msat = 0;
919 let mut fee_proportional_millionths = 0;
920 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
921 fee_base_msat = fees.base_msat;
922 fee_proportional_millionths = fees.proportional_millionths;
925 node_id: $dest_node_id.clone(),
926 candidate: $candidate.clone(),
928 src_lowest_inbound_fees: RoutingFees {
929 base_msat: fee_base_msat,
930 proportional_millionths: fee_proportional_millionths,
932 next_hops_fee_msat: u64::max_value(),
933 hop_use_fee_msat: u64::max_value(),
934 total_fee_msat: u64::max_value(),
935 path_htlc_minimum_msat,
936 path_penalty_msat: u64::max_value(),
937 was_processed: false,
938 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
939 value_contribution_msat,
943 #[allow(unused_mut)] // We only use the mut in cfg(test)
944 let mut should_process = !old_entry.was_processed;
945 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
947 // In test/fuzzing builds, we do extra checks to make sure the skipping
948 // of already-seen nodes only happens in cases we expect (see below).
949 if !should_process { should_process = true; }
953 let mut hop_use_fee_msat = 0;
954 let mut total_fee_msat = $next_hops_fee_msat;
956 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
957 // will have the same effective-fee
958 if $src_node_id != our_node_id {
959 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
960 // max_value means we'll always fail
961 // the old_entry.total_fee_msat > total_fee_msat check
962 None => total_fee_msat = u64::max_value(),
964 hop_use_fee_msat = fee_msat;
965 total_fee_msat += hop_use_fee_msat;
966 // When calculating the lowest inbound fees to a node, we
967 // calculate fees here not based on the actual value we think
968 // will flow over this channel, but on the minimum value that
969 // we'll accept flowing over it. The minimum accepted value
970 // is a constant through each path collection run, ensuring
971 // consistent basis. Otherwise we may later find a
972 // different path to the source node that is more expensive,
973 // but which we consider to be cheaper because we are capacity
974 // constrained and the relative fee becomes lower.
975 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
976 .map(|a| a.checked_add(total_fee_msat)) {
981 total_fee_msat = u64::max_value();
988 let path_penalty_msat = $next_hops_path_penalty_msat.checked_add(
989 scorer.channel_penalty_msat(short_channel_id, amount_to_transfer_over_msat, *available_liquidity_msat,
990 &$src_node_id, &$dest_node_id)).unwrap_or_else(|| u64::max_value());
991 let new_graph_node = RouteGraphNode {
992 node_id: $src_node_id,
993 lowest_fee_to_peer_through_node: total_fee_msat,
994 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
995 total_cltv_delta: hop_total_cltv_delta,
996 value_contribution_msat: value_contribution_msat,
997 path_htlc_minimum_msat,
1001 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1002 // if this way is cheaper than the already known
1003 // (considering the cost to "reach" this channel from the route destination,
1004 // the cost of using this channel,
1005 // and the cost of routing to the source node of this channel).
1006 // Also, consider that htlc_minimum_msat_difference, because we might end up
1007 // paying it. Consider the following exploit:
1008 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1009 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1010 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1011 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1013 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1014 // but it may require additional tracking - we don't want to double-count
1015 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1016 // can't use something that may decrease on future hops.
1017 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1018 .checked_add(old_entry.path_penalty_msat)
1019 .unwrap_or_else(|| u64::max_value());
1020 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1021 .checked_add(path_penalty_msat)
1022 .unwrap_or_else(|| u64::max_value());
1024 if !old_entry.was_processed && new_cost < old_cost {
1025 targets.push(new_graph_node);
1026 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1027 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1028 old_entry.total_fee_msat = total_fee_msat;
1029 old_entry.node_id = $dest_node_id.clone();
1030 old_entry.candidate = $candidate.clone();
1031 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1032 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1033 old_entry.path_penalty_msat = path_penalty_msat;
1034 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1036 old_entry.value_contribution_msat = value_contribution_msat;
1038 did_add_update_path_to_src_node = true;
1039 } else if old_entry.was_processed && new_cost < old_cost {
1040 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1042 // If we're skipping processing a node which was previously
1043 // processed even though we found another path to it with a
1044 // cheaper fee, check that it was because the second path we
1045 // found (which we are processing now) has a lower value
1046 // contribution due to an HTLC minimum limit.
1048 // e.g. take a graph with two paths from node 1 to node 2, one
1049 // through channel A, and one through channel B. Channel A and
1050 // B are both in the to-process heap, with their scores set by
1051 // a higher htlc_minimum than fee.
1052 // Channel A is processed first, and the channels onwards from
1053 // node 1 are added to the to-process heap. Thereafter, we pop
1054 // Channel B off of the heap, note that it has a much more
1055 // restrictive htlc_maximum_msat, and recalculate the fees for
1056 // all of node 1's channels using the new, reduced, amount.
1058 // This would be bogus - we'd be selecting a higher-fee path
1059 // with a lower htlc_maximum_msat instead of the one we'd
1060 // already decided to use.
1061 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1063 value_contribution_msat + path_penalty_msat <
1064 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1072 did_add_update_path_to_src_node
1076 let empty_node_features = NodeFeatures::empty();
1077 // Find ways (channels with destination) to reach a given node and store them
1078 // in the corresponding data structures (routing graph etc).
1079 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1080 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1081 // This data can later be helpful to optimize routing (pay lower fees).
1082 macro_rules! add_entries_to_cheapest_to_target_node {
1083 ( $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, $next_hops_cltv_delta: expr ) => {
1084 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1085 let was_processed = elem.was_processed;
1086 elem.was_processed = true;
1089 // Entries are added to dist in add_entry!() when there is a channel from a node.
1090 // Because there are no channels from payee, it will not have a dist entry at this point.
1091 // If we're processing any other node, it is always be the result of a channel from it.
1092 assert_eq!($node_id, payee_node_id);
1097 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1098 for details in first_channels {
1099 let candidate = CandidateRouteHop::FirstHop { details };
1100 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);
1104 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1107 &empty_node_features
1110 if !features.requires_unknown_bits() {
1111 for chan_id in $node.channels.iter() {
1112 let chan = network_channels.get(chan_id).unwrap();
1113 if !chan.features.requires_unknown_bits() {
1114 let (directed_channel, source) =
1115 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1116 if first_hops.is_none() || *source != our_node_id {
1117 if let Some(direction) = directed_channel.direction() {
1118 if direction.enabled {
1119 let candidate = CandidateRouteHop::PublicHop {
1120 info: directed_channel.with_update().unwrap(),
1121 short_channel_id: *chan_id,
1123 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);
1134 let mut payment_paths = Vec::<PaymentPath>::new();
1136 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1137 'paths_collection: loop {
1138 // For every new path, start from scratch, except
1139 // bookkept_channels_liquidity_available_msat, which will improve
1140 // the further iterations of path finding. Also don't erase first_hop_targets.
1143 hit_minimum_limit = false;
1145 // If first hop is a private channel and the only way to reach the payee, this is the only
1146 // place where it could be added.
1147 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1148 for details in first_channels {
1149 let candidate = CandidateRouteHop::FirstHop { details };
1150 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1151 log_trace!(logger, "{} direct route to payee via SCID {}", if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1155 // Add the payee as a target, so that the payee-to-payer
1156 // search algorithm knows what to start with.
1157 match network_nodes.get(&payee_node_id) {
1158 // The payee is not in our network graph, so nothing to add here.
1159 // There is still a chance of reaching them via last_hops though,
1160 // so don't yet fail the payment here.
1161 // If not, targets.pop() will not even let us enter the loop in step 2.
1164 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0);
1169 // If a caller provided us with last hops, add them to routing targets. Since this happens
1170 // earlier than general path finding, they will be somewhat prioritized, although currently
1171 // it matters only if the fees are exactly the same.
1172 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1173 let first_hop_in_route = &(route.0)[0];
1174 let have_hop_src_in_graph =
1175 // Only add the hops in this route to our candidate set if either
1176 // we have a direct channel to the first hop or the first hop is
1177 // in the regular network graph.
1178 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1179 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1180 if have_hop_src_in_graph {
1181 // We start building the path from reverse, i.e., from payee
1182 // to the first RouteHintHop in the path.
1183 let hop_iter = route.0.iter().rev();
1184 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1185 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1186 let mut hop_used = true;
1187 let mut aggregate_next_hops_fee_msat: u64 = 0;
1188 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1189 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1190 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1192 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1193 let source = NodeId::from_pubkey(&hop.src_node_id);
1194 let target = NodeId::from_pubkey(&prev_hop_id);
1195 let candidate = network_channels
1196 .get(&hop.short_channel_id)
1197 .and_then(|channel| channel.as_directed_to(&target))
1198 .and_then(|(channel, _)| channel.with_update())
1199 .map(|info| CandidateRouteHop::PublicHop {
1201 short_channel_id: hop.short_channel_id,
1203 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1204 let capacity_msat = candidate.effective_capacity().as_msat();
1205 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1206 .checked_add(scorer.channel_penalty_msat(hop.short_channel_id, final_value_msat, capacity_msat, &source, &target))
1207 .unwrap_or_else(|| u64::max_value());
1209 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1210 .checked_add(hop.cltv_expiry_delta as u32)
1211 .unwrap_or_else(|| u32::max_value());
1213 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) {
1214 // If this hop was not used then there is no use checking the preceding hops
1215 // in the RouteHint. We can break by just searching for a direct channel between
1216 // last checked hop and first_hop_targets
1220 // Searching for a direct channel between last checked hop and first_hop_targets
1221 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1222 for details in first_channels {
1223 let candidate = CandidateRouteHop::FirstHop { details };
1224 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);
1232 // In the next values of the iterator, the aggregate fees already reflects
1233 // the sum of value sent from payer (final_value_msat) and routing fees
1234 // for the last node in the RouteHint. We need to just add the fees to
1235 // route through the current node so that the preceeding node (next iteration)
1237 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1238 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1239 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1241 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1242 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1243 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1244 .checked_add(hop_htlc_minimum_msat_inc);
1245 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1247 if idx == route.0.len() - 1 {
1248 // The last hop in this iterator is the first hop in
1249 // overall RouteHint.
1250 // If this hop connects to a node with which we have a direct channel,
1251 // ignore the network graph and, if the last hop was added, add our
1252 // direct channel to the candidate set.
1254 // Note that we *must* check if the last hop was added as `add_entry`
1255 // always assumes that the third argument is a node to which we have a
1257 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1258 for details in first_channels {
1259 let candidate = CandidateRouteHop::FirstHop { details };
1260 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);
1268 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1270 // At this point, targets are filled with the data from first and
1271 // last hops communicated by the caller, and the payment receiver.
1272 let mut found_new_path = false;
1275 // If this loop terminates due the exhaustion of targets, two situations are possible:
1276 // - not enough outgoing liquidity:
1277 // 0 < already_collected_value_msat < final_value_msat
1278 // - enough outgoing liquidity:
1279 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1280 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1281 // paths_collection will be stopped because found_new_path==false.
1282 // This is not necessarily a routing failure.
1283 '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() {
1285 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1286 // traversing the graph and arrange the path out of what we found.
1287 if node_id == our_node_id {
1288 let mut new_entry = dist.remove(&our_node_id).unwrap();
1289 let mut ordered_hops = vec!((new_entry.clone(), NodeFeatures::empty()));
1292 let mut features_set = false;
1293 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1294 for details in first_channels {
1295 if details.short_channel_id.unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1296 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1297 features_set = true;
1303 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1304 if let Some(node_info) = node.announcement_info.as_ref() {
1305 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1307 ordered_hops.last_mut().unwrap().1 = NodeFeatures::empty();
1310 // We can fill in features for everything except hops which were
1311 // provided via the invoice we're paying. We could guess based on the
1312 // recipient's features but for now we simply avoid guessing at all.
1316 // Means we succesfully traversed from the payer to the payee, now
1317 // save this path for the payment route. Also, update the liquidity
1318 // remaining on the used hops, so that we take them into account
1319 // while looking for more paths.
1320 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1324 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1325 Some(payment_hop) => payment_hop,
1326 // We can't arrive at None because, if we ever add an entry to targets,
1327 // we also fill in the entry in dist (see add_entry!).
1328 None => unreachable!(),
1330 // We "propagate" the fees one hop backward (topologically) here,
1331 // so that fees paid for a HTLC forwarding on the current channel are
1332 // associated with the previous channel (where they will be subtracted).
1333 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1334 ordered_hops.push((new_entry.clone(), NodeFeatures::empty()));
1336 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1337 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1339 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1340 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1342 let mut payment_path = PaymentPath {hops: ordered_hops};
1344 // We could have possibly constructed a slightly inconsistent path: since we reduce
1345 // value being transferred along the way, we could have violated htlc_minimum_msat
1346 // on some channels we already passed (assuming dest->source direction). Here, we
1347 // recompute the fees again, so that if that's the case, we match the currently
1348 // underpaid htlc_minimum_msat with fees.
1349 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1351 // Since a path allows to transfer as much value as
1352 // the smallest channel it has ("bottleneck"), we should recompute
1353 // the fees so sender HTLC don't overpay fees when traversing
1354 // larger channels than the bottleneck. This may happen because
1355 // when we were selecting those channels we were not aware how much value
1356 // this path will transfer, and the relative fee for them
1357 // might have been computed considering a larger value.
1358 // Remember that we used these channels so that we don't rely
1359 // on the same liquidity in future paths.
1360 let mut prevented_redundant_path_selection = false;
1361 for (payment_hop, _) in payment_path.hops.iter() {
1362 let channel_liquidity_available_msat = bookkept_channels_liquidity_available_msat.get_mut(&payment_hop.candidate.short_channel_id()).unwrap();
1363 let mut spent_on_hop_msat = value_contribution_msat;
1364 let next_hops_fee_msat = payment_hop.next_hops_fee_msat;
1365 spent_on_hop_msat += next_hops_fee_msat;
1366 if spent_on_hop_msat == *channel_liquidity_available_msat {
1367 // If this path used all of this channel's available liquidity, we know
1368 // this path will not be selected again in the next loop iteration.
1369 prevented_redundant_path_selection = true;
1371 *channel_liquidity_available_msat -= spent_on_hop_msat;
1373 if !prevented_redundant_path_selection {
1374 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1375 // we'll probably end up picking the same path again on the next iteration.
1376 // Decrease the available liquidity of a hop in the middle of the path.
1377 let victim_scid = payment_path.hops[(payment_path.hops.len() - 1) / 2].0.candidate.short_channel_id();
1378 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1379 let victim_liquidity = bookkept_channels_liquidity_available_msat.get_mut(&victim_scid).unwrap();
1380 *victim_liquidity = 0;
1383 // Track the total amount all our collected paths allow to send so that we:
1384 // - know when to stop looking for more paths
1385 // - know which of the hops are useless considering how much more sats we need
1386 // (contributes_sufficient_value)
1387 already_collected_value_msat += value_contribution_msat;
1389 payment_paths.push(payment_path);
1390 found_new_path = true;
1391 break 'path_construction;
1394 // If we found a path back to the payee, we shouldn't try to process it again. This is
1395 // the equivalent of the `elem.was_processed` check in
1396 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1397 if node_id == payee_node_id { continue 'path_construction; }
1399 // Otherwise, since the current target node is not us,
1400 // keep "unrolling" the payment graph from payee to payer by
1401 // finding a way to reach the current target from the payer side.
1402 match network_nodes.get(&node_id) {
1405 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);
1411 // If we don't support MPP, no use trying to gather more value ever.
1412 break 'paths_collection;
1416 // Stop either when the recommended value is reached or if no new path was found in this
1418 // In the latter case, making another path finding attempt won't help,
1419 // because we deterministically terminated the search due to low liquidity.
1420 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1421 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1422 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1423 break 'paths_collection;
1424 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1425 // Further, if this was our first walk of the graph, and we weren't limited by an
1426 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1427 // limited by an htlc_minimum_msat value, find another path with a higher value,
1428 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1429 // still keeping a lower total fee than this path.
1430 if !hit_minimum_limit {
1431 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1432 break 'paths_collection;
1434 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1435 path_value_msat = recommended_value_msat;
1440 if payment_paths.len() == 0 {
1441 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1444 if already_collected_value_msat < final_value_msat {
1445 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1448 // Sort by total fees and take the best paths.
1449 payment_paths.sort_by_key(|path| path.get_total_fee_paid_msat());
1450 if payment_paths.len() > 50 {
1451 payment_paths.truncate(50);
1454 // Draw multiple sufficient routes by randomly combining the selected paths.
1455 let mut drawn_routes = Vec::new();
1456 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 12]);
1457 let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
1459 let num_permutations = payment_paths.len();
1460 for _ in 0..num_permutations {
1461 let mut cur_route = Vec::<PaymentPath>::new();
1462 let mut aggregate_route_value_msat = 0;
1465 // Do a Fisher-Yates shuffle to create a random permutation of the payment paths
1466 for cur_index in (1..payment_paths.len()).rev() {
1467 prng.process_in_place(&mut random_index_bytes);
1468 let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
1469 payment_paths.swap(cur_index, random_index);
1473 for payment_path in &payment_paths {
1474 cur_route.push(payment_path.clone());
1475 aggregate_route_value_msat += payment_path.get_value_msat();
1476 if aggregate_route_value_msat > final_value_msat {
1477 // Last path likely overpaid. Substract it from the most expensive
1478 // (in terms of proportional fee) path in this route and recompute fees.
1479 // This might be not the most economically efficient way, but fewer paths
1480 // also makes routing more reliable.
1481 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1483 // First, we drop some expensive low-value paths entirely if possible, since fewer
1484 // paths is better: the payment is less likely to fail. In order to do so, we sort
1485 // by value and fall back to total fees paid, i.e., in case of equal values we
1486 // prefer lower cost paths.
1487 cur_route.sort_unstable_by(|a, b| {
1488 a.get_value_msat().cmp(&b.get_value_msat())
1489 // Reverse ordering for fees, so we drop higher-fee paths first
1490 .then_with(|| b.get_total_fee_paid_msat().saturating_add(b.get_path_penalty_msat())
1491 .cmp(&a.get_total_fee_paid_msat().saturating_add(a.get_path_penalty_msat())))
1494 // We should make sure that at least 1 path left.
1495 let mut paths_left = cur_route.len();
1496 cur_route.retain(|path| {
1497 if paths_left == 1 {
1500 let mut keep = true;
1501 let path_value_msat = path.get_value_msat();
1502 if path_value_msat <= overpaid_value_msat {
1504 overpaid_value_msat -= path_value_msat;
1510 if overpaid_value_msat == 0 {
1514 assert!(cur_route.len() > 0);
1517 // Now, substract the overpaid value from the most-expensive path.
1518 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1519 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1520 cur_route.sort_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1521 let expensive_payment_path = cur_route.first_mut().unwrap();
1522 // We already dropped all the small channels above, meaning all the
1523 // remaining channels are larger than remaining overpaid_value_msat.
1524 // Thus, this can't be negative.
1525 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1526 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1530 drawn_routes.push(cur_route);
1534 // Select the best route by lowest total fee.
1535 drawn_routes.sort_by_key(|paths| paths.iter().map(|path| path.get_total_fee_paid_msat()).sum::<u64>());
1536 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1537 for payment_path in drawn_routes.first().unwrap() {
1538 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1540 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)})?,
1541 node_features: node_features.clone(),
1542 short_channel_id: payment_hop.candidate.short_channel_id(),
1543 channel_features: payment_hop.candidate.features(),
1544 fee_msat: payment_hop.fee_msat,
1545 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1547 }).collect::<Vec<_>>();
1548 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1549 // applicable for the previous hop.
1550 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1551 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1553 selected_paths.push(path);
1556 if let Some(features) = &payment_params.features {
1557 for path in selected_paths.iter_mut() {
1558 if let Ok(route_hop) = path.last_mut().unwrap() {
1559 route_hop.node_features = features.to_context();
1565 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1566 payment_params: Some(payment_params.clone()),
1568 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1572 // When an adversarial intermediary node observes a payment, it may be able to infer its
1573 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1574 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1575 // payment path by adding a randomized 'shadow route' offset to the final hop.
1576 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]) {
1577 let network_channels = network_graph.channels();
1578 let network_nodes = network_graph.nodes();
1580 for path in route.paths.iter_mut() {
1581 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1583 // Choose the last publicly known node as the starting point for the random walk
1584 if let Some(starting_hop) = path.iter().rev().find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1585 let mut cur_node_id = NodeId::from_pubkey(&starting_hop.pubkey);
1587 // Init PRNG with path nonce
1588 let mut path_nonce = [0u8; 12];
1589 path_nonce.copy_from_slice(&cur_node_id.as_slice()[..12]);
1590 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1591 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1593 // Pick a random path length in [1 .. 3]
1594 prng.process_in_place(&mut random_path_bytes);
1595 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1597 for _random_hop in 0..random_walk_length {
1598 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1599 // Randomly choose the next hop
1600 prng.process_in_place(&mut random_path_bytes);
1601 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes).checked_rem(cur_node.channels.len())
1602 .and_then(|index| cur_node.channels.get(index))
1603 .and_then(|id| network_channels.get(id)) {
1604 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1605 dir_info.direction().map(|channel_update_info|
1606 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1607 .checked_add(channel_update_info.cltv_expiry_delta.into())
1608 .unwrap_or(shadow_ctlv_expiry_delta_offset));
1609 cur_node_id = *next_id;
1615 // If the entire path is private, choose a random offset from multiples of
1616 // MEDIAN_HOP_CLTV_EXPIRY_DELTA
1617 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 8]);
1618 let mut random_bytes = [0u8; 4];
1619 prng.process_in_place(&mut random_bytes);
1620 let random_walk_length = u32::from_be_bytes(random_bytes).wrapping_rem(3).wrapping_add(1);
1621 shadow_ctlv_expiry_delta_offset = random_walk_length * MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1624 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1625 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1626 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1628 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1629 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1630 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1631 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1632 max_path_offset = cmp::max(
1633 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1634 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1635 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1637 // Add 'shadow' CLTV offset to the final hop
1638 if let Some(last_hop) = path.last_mut() {
1639 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1640 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1647 use routing::network_graph::{NetworkGraph, NetGraphMsgHandler, NodeId};
1648 use routing::router::{get_route, add_random_cltv_offset, PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA};
1649 use routing::scoring::Score;
1650 use chain::transaction::OutPoint;
1651 use chain::keysinterface::KeysInterface;
1652 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1653 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1654 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1655 use ln::channelmanager;
1656 use util::test_utils;
1657 use util::chacha20::ChaCha20;
1658 use util::ser::Writeable;
1660 use util::ser::Writer;
1662 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1663 use bitcoin::hashes::Hash;
1664 use bitcoin::network::constants::Network;
1665 use bitcoin::blockdata::constants::genesis_block;
1666 use bitcoin::blockdata::script::Builder;
1667 use bitcoin::blockdata::opcodes;
1668 use bitcoin::blockdata::transaction::TxOut;
1672 use bitcoin::secp256k1::key::{PublicKey,SecretKey};
1673 use bitcoin::secp256k1::{Secp256k1, All};
1676 use sync::{self, Arc};
1678 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1679 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1680 channelmanager::ChannelDetails {
1681 channel_id: [0; 32],
1682 counterparty: channelmanager::ChannelCounterparty {
1685 unspendable_punishment_reserve: 0,
1686 forwarding_info: None,
1688 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1690 inbound_scid_alias: None,
1691 channel_value_satoshis: 0,
1694 outbound_capacity_msat,
1695 inbound_capacity_msat: 42,
1696 unspendable_punishment_reserve: None,
1697 confirmations_required: None,
1698 force_close_spend_delay: None,
1699 is_outbound: true, is_funding_locked: true,
1700 is_usable: true, is_public: true,
1704 // Using the same keys for LN and BTC ids
1706 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1707 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1709 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1710 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1712 let unsigned_announcement = UnsignedChannelAnnouncement {
1714 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1718 bitcoin_key_1: node_id_1,
1719 bitcoin_key_2: node_id_2,
1720 excess_data: Vec::new(),
1723 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1724 let valid_announcement = ChannelAnnouncement {
1725 node_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1726 node_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1727 bitcoin_signature_1: secp_ctx.sign(&msghash, node_1_privkey),
1728 bitcoin_signature_2: secp_ctx.sign(&msghash, node_2_privkey),
1729 contents: unsigned_announcement.clone(),
1731 match net_graph_msg_handler.handle_channel_announcement(&valid_announcement) {
1732 Ok(res) => assert!(res),
1738 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1739 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1741 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1742 let valid_channel_update = ChannelUpdate {
1743 signature: secp_ctx.sign(&msghash, node_privkey),
1744 contents: update.clone()
1747 match net_graph_msg_handler.handle_channel_update(&valid_channel_update) {
1748 Ok(res) => assert!(res),
1753 fn add_or_update_node(
1754 net_graph_msg_handler: &NetGraphMsgHandler<Arc<NetworkGraph>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1755 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1757 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1758 let unsigned_announcement = UnsignedNodeAnnouncement {
1764 addresses: Vec::new(),
1765 excess_address_data: Vec::new(),
1766 excess_data: Vec::new(),
1768 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1769 let valid_announcement = NodeAnnouncement {
1770 signature: secp_ctx.sign(&msghash, node_privkey),
1771 contents: unsigned_announcement.clone()
1774 match net_graph_msg_handler.handle_node_announcement(&valid_announcement) {
1780 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
1781 let privkeys: Vec<SecretKey> = (2..10).map(|i| {
1782 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
1785 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
1787 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
1788 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
1790 (our_privkey, our_id, privkeys, pubkeys)
1793 fn id_to_feature_flags(id: u8) -> Vec<u8> {
1794 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
1795 // test for it later.
1796 let idx = (id - 1) * 2 + 1;
1798 vec![1 << (idx - 8*3), 0, 0, 0]
1799 } else if idx > 8*2 {
1800 vec![1 << (idx - 8*2), 0, 0]
1801 } else if idx > 8*1 {
1802 vec![1 << (idx - 8*1), 0]
1808 fn build_graph() -> (
1810 sync::Arc<NetworkGraph>,
1811 NetGraphMsgHandler<sync::Arc<NetworkGraph>, sync::Arc<test_utils::TestChainSource>, sync::Arc<crate::util::test_utils::TestLogger>>,
1812 sync::Arc<test_utils::TestChainSource>,
1813 sync::Arc<test_utils::TestLogger>,
1815 let secp_ctx = Secp256k1::new();
1816 let logger = Arc::new(test_utils::TestLogger::new());
1817 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
1818 let network_graph = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
1819 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
1820 // Build network from our_id to node6:
1822 // -1(1)2- node0 -1(3)2-
1824 // our_id -1(12)2- node7 -1(13)2--- node2
1826 // -1(2)2- node1 -1(4)2-
1829 // chan1 1-to-2: disabled
1830 // chan1 2-to-1: enabled, 0 fee
1832 // chan2 1-to-2: enabled, ignored fee
1833 // chan2 2-to-1: enabled, 0 fee
1835 // chan3 1-to-2: enabled, 0 fee
1836 // chan3 2-to-1: enabled, 100 msat fee
1838 // chan4 1-to-2: enabled, 100% fee
1839 // chan4 2-to-1: enabled, 0 fee
1841 // chan12 1-to-2: enabled, ignored fee
1842 // chan12 2-to-1: enabled, 0 fee
1844 // chan13 1-to-2: enabled, 200% fee
1845 // chan13 2-to-1: enabled, 0 fee
1848 // -1(5)2- node3 -1(8)2--
1852 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
1854 // -1(7)2- node5 -1(10)2-
1856 // Channels 5, 8, 9 and 10 are private channels.
1858 // chan5 1-to-2: enabled, 100 msat fee
1859 // chan5 2-to-1: enabled, 0 fee
1861 // chan6 1-to-2: enabled, 0 fee
1862 // chan6 2-to-1: enabled, 0 fee
1864 // chan7 1-to-2: enabled, 100% fee
1865 // chan7 2-to-1: enabled, 0 fee
1867 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
1868 // chan8 2-to-1: enabled, 0 fee
1870 // chan9 1-to-2: enabled, 1001 msat fee
1871 // chan9 2-to-1: enabled, 0 fee
1873 // chan10 1-to-2: enabled, 0 fee
1874 // chan10 2-to-1: enabled, 0 fee
1876 // chan11 1-to-2: enabled, 0 fee
1877 // chan11 2-to-1: enabled, 0 fee
1879 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
1881 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
1882 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1883 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1884 short_channel_id: 1,
1887 cltv_expiry_delta: 0,
1888 htlc_minimum_msat: 0,
1889 htlc_maximum_msat: OptionalField::Absent,
1891 fee_proportional_millionths: 0,
1892 excess_data: Vec::new()
1895 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
1897 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
1898 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1899 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1900 short_channel_id: 2,
1903 cltv_expiry_delta: (5 << 4) | 3,
1904 htlc_minimum_msat: 0,
1905 htlc_maximum_msat: OptionalField::Absent,
1906 fee_base_msat: u32::max_value(),
1907 fee_proportional_millionths: u32::max_value(),
1908 excess_data: Vec::new()
1910 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1911 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1912 short_channel_id: 2,
1915 cltv_expiry_delta: 0,
1916 htlc_minimum_msat: 0,
1917 htlc_maximum_msat: OptionalField::Absent,
1919 fee_proportional_millionths: 0,
1920 excess_data: Vec::new()
1923 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
1925 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
1926 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
1927 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1928 short_channel_id: 12,
1931 cltv_expiry_delta: (5 << 4) | 3,
1932 htlc_minimum_msat: 0,
1933 htlc_maximum_msat: OptionalField::Absent,
1934 fee_base_msat: u32::max_value(),
1935 fee_proportional_millionths: u32::max_value(),
1936 excess_data: Vec::new()
1938 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
1939 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1940 short_channel_id: 12,
1943 cltv_expiry_delta: 0,
1944 htlc_minimum_msat: 0,
1945 htlc_maximum_msat: OptionalField::Absent,
1947 fee_proportional_millionths: 0,
1948 excess_data: Vec::new()
1951 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
1953 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
1954 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
1955 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1956 short_channel_id: 3,
1959 cltv_expiry_delta: (3 << 4) | 1,
1960 htlc_minimum_msat: 0,
1961 htlc_maximum_msat: OptionalField::Absent,
1963 fee_proportional_millionths: 0,
1964 excess_data: Vec::new()
1966 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1967 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1968 short_channel_id: 3,
1971 cltv_expiry_delta: (3 << 4) | 2,
1972 htlc_minimum_msat: 0,
1973 htlc_maximum_msat: OptionalField::Absent,
1975 fee_proportional_millionths: 0,
1976 excess_data: Vec::new()
1979 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
1980 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
1981 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1982 short_channel_id: 4,
1985 cltv_expiry_delta: (4 << 4) | 1,
1986 htlc_minimum_msat: 0,
1987 htlc_maximum_msat: OptionalField::Absent,
1989 fee_proportional_millionths: 1000000,
1990 excess_data: Vec::new()
1992 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
1993 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1994 short_channel_id: 4,
1997 cltv_expiry_delta: (4 << 4) | 2,
1998 htlc_minimum_msat: 0,
1999 htlc_maximum_msat: OptionalField::Absent,
2001 fee_proportional_millionths: 0,
2002 excess_data: Vec::new()
2005 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2006 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2007 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2008 short_channel_id: 13,
2011 cltv_expiry_delta: (13 << 4) | 1,
2012 htlc_minimum_msat: 0,
2013 htlc_maximum_msat: OptionalField::Absent,
2015 fee_proportional_millionths: 2000000,
2016 excess_data: Vec::new()
2018 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2019 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2020 short_channel_id: 13,
2023 cltv_expiry_delta: (13 << 4) | 2,
2024 htlc_minimum_msat: 0,
2025 htlc_maximum_msat: OptionalField::Absent,
2027 fee_proportional_millionths: 0,
2028 excess_data: Vec::new()
2031 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2033 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2034 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2035 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2036 short_channel_id: 6,
2039 cltv_expiry_delta: (6 << 4) | 1,
2040 htlc_minimum_msat: 0,
2041 htlc_maximum_msat: OptionalField::Absent,
2043 fee_proportional_millionths: 0,
2044 excess_data: Vec::new()
2046 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2047 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2048 short_channel_id: 6,
2051 cltv_expiry_delta: (6 << 4) | 2,
2052 htlc_minimum_msat: 0,
2053 htlc_maximum_msat: OptionalField::Absent,
2055 fee_proportional_millionths: 0,
2056 excess_data: Vec::new(),
2059 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2060 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2061 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2062 short_channel_id: 11,
2065 cltv_expiry_delta: (11 << 4) | 1,
2066 htlc_minimum_msat: 0,
2067 htlc_maximum_msat: OptionalField::Absent,
2069 fee_proportional_millionths: 0,
2070 excess_data: Vec::new()
2072 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2073 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2074 short_channel_id: 11,
2077 cltv_expiry_delta: (11 << 4) | 2,
2078 htlc_minimum_msat: 0,
2079 htlc_maximum_msat: OptionalField::Absent,
2081 fee_proportional_millionths: 0,
2082 excess_data: Vec::new()
2085 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2087 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2089 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2090 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2091 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2092 short_channel_id: 7,
2095 cltv_expiry_delta: (7 << 4) | 1,
2096 htlc_minimum_msat: 0,
2097 htlc_maximum_msat: OptionalField::Absent,
2099 fee_proportional_millionths: 1000000,
2100 excess_data: Vec::new()
2102 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2103 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2104 short_channel_id: 7,
2107 cltv_expiry_delta: (7 << 4) | 2,
2108 htlc_minimum_msat: 0,
2109 htlc_maximum_msat: OptionalField::Absent,
2111 fee_proportional_millionths: 0,
2112 excess_data: Vec::new()
2115 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2117 (secp_ctx, network_graph, net_graph_msg_handler, chain_monitor, logger)
2121 fn simple_route_test() {
2122 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2123 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2124 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2125 let scorer = test_utils::TestScorer::with_penalty(0);
2126 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2127 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2129 // Simple route to 2 via 1
2131 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) {
2132 assert_eq!(err, "Cannot send a payment of 0 msat");
2133 } else { panic!(); }
2135 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2136 assert_eq!(route.paths[0].len(), 2);
2138 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2139 assert_eq!(route.paths[0][0].short_channel_id, 2);
2140 assert_eq!(route.paths[0][0].fee_msat, 100);
2141 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2142 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2143 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2145 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2146 assert_eq!(route.paths[0][1].short_channel_id, 4);
2147 assert_eq!(route.paths[0][1].fee_msat, 100);
2148 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2149 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2150 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2154 fn invalid_first_hop_test() {
2155 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2156 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2157 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2158 let scorer = test_utils::TestScorer::with_penalty(0);
2159 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2160 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2162 // Simple route to 2 via 1
2164 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2166 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2167 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) {
2168 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2169 } else { panic!(); }
2171 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2172 assert_eq!(route.paths[0].len(), 2);
2176 fn htlc_minimum_test() {
2177 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2178 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2179 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2180 let scorer = test_utils::TestScorer::with_penalty(0);
2181 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2182 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2184 // Simple route to 2 via 1
2186 // Disable other paths
2187 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2188 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2189 short_channel_id: 12,
2191 flags: 2, // to disable
2192 cltv_expiry_delta: 0,
2193 htlc_minimum_msat: 0,
2194 htlc_maximum_msat: OptionalField::Absent,
2196 fee_proportional_millionths: 0,
2197 excess_data: Vec::new()
2199 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2200 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2201 short_channel_id: 3,
2203 flags: 2, // to disable
2204 cltv_expiry_delta: 0,
2205 htlc_minimum_msat: 0,
2206 htlc_maximum_msat: OptionalField::Absent,
2208 fee_proportional_millionths: 0,
2209 excess_data: Vec::new()
2211 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2212 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2213 short_channel_id: 13,
2215 flags: 2, // to disable
2216 cltv_expiry_delta: 0,
2217 htlc_minimum_msat: 0,
2218 htlc_maximum_msat: OptionalField::Absent,
2220 fee_proportional_millionths: 0,
2221 excess_data: Vec::new()
2223 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2224 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2225 short_channel_id: 6,
2227 flags: 2, // to disable
2228 cltv_expiry_delta: 0,
2229 htlc_minimum_msat: 0,
2230 htlc_maximum_msat: OptionalField::Absent,
2232 fee_proportional_millionths: 0,
2233 excess_data: Vec::new()
2235 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2236 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2237 short_channel_id: 7,
2239 flags: 2, // to disable
2240 cltv_expiry_delta: 0,
2241 htlc_minimum_msat: 0,
2242 htlc_maximum_msat: OptionalField::Absent,
2244 fee_proportional_millionths: 0,
2245 excess_data: Vec::new()
2248 // Check against amount_to_transfer_over_msat.
2249 // Set minimal HTLC of 200_000_000 msat.
2250 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2251 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2252 short_channel_id: 2,
2255 cltv_expiry_delta: 0,
2256 htlc_minimum_msat: 200_000_000,
2257 htlc_maximum_msat: OptionalField::Absent,
2259 fee_proportional_millionths: 0,
2260 excess_data: Vec::new()
2263 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2265 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2266 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2267 short_channel_id: 4,
2270 cltv_expiry_delta: 0,
2271 htlc_minimum_msat: 0,
2272 htlc_maximum_msat: OptionalField::Present(199_999_999),
2274 fee_proportional_millionths: 0,
2275 excess_data: Vec::new()
2278 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2279 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) {
2280 assert_eq!(err, "Failed to find a path to the given destination");
2281 } else { panic!(); }
2283 // Lift the restriction on the first hop.
2284 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2285 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2286 short_channel_id: 2,
2289 cltv_expiry_delta: 0,
2290 htlc_minimum_msat: 0,
2291 htlc_maximum_msat: OptionalField::Absent,
2293 fee_proportional_millionths: 0,
2294 excess_data: Vec::new()
2297 // A payment above the minimum should pass
2298 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();
2299 assert_eq!(route.paths[0].len(), 2);
2303 fn htlc_minimum_overpay_test() {
2304 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2305 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2306 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2307 let scorer = test_utils::TestScorer::with_penalty(0);
2308 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2309 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2311 // A route to node#2 via two paths.
2312 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2313 // Thus, they can't send 60 without overpaying.
2314 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2315 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2316 short_channel_id: 2,
2319 cltv_expiry_delta: 0,
2320 htlc_minimum_msat: 35_000,
2321 htlc_maximum_msat: OptionalField::Present(40_000),
2323 fee_proportional_millionths: 0,
2324 excess_data: Vec::new()
2326 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2327 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2328 short_channel_id: 12,
2331 cltv_expiry_delta: 0,
2332 htlc_minimum_msat: 35_000,
2333 htlc_maximum_msat: OptionalField::Present(40_000),
2335 fee_proportional_millionths: 0,
2336 excess_data: Vec::new()
2340 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2341 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2342 short_channel_id: 13,
2345 cltv_expiry_delta: 0,
2346 htlc_minimum_msat: 0,
2347 htlc_maximum_msat: OptionalField::Absent,
2349 fee_proportional_millionths: 0,
2350 excess_data: Vec::new()
2352 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2353 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2354 short_channel_id: 4,
2357 cltv_expiry_delta: 0,
2358 htlc_minimum_msat: 0,
2359 htlc_maximum_msat: OptionalField::Absent,
2361 fee_proportional_millionths: 0,
2362 excess_data: Vec::new()
2365 // Disable other paths
2366 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2367 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2368 short_channel_id: 1,
2370 flags: 2, // to disable
2371 cltv_expiry_delta: 0,
2372 htlc_minimum_msat: 0,
2373 htlc_maximum_msat: OptionalField::Absent,
2375 fee_proportional_millionths: 0,
2376 excess_data: Vec::new()
2379 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2380 // Overpay fees to hit htlc_minimum_msat.
2381 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2382 // TODO: this could be better balanced to overpay 10k and not 15k.
2383 assert_eq!(overpaid_fees, 15_000);
2385 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2386 // while taking even more fee to match htlc_minimum_msat.
2387 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2388 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2389 short_channel_id: 12,
2392 cltv_expiry_delta: 0,
2393 htlc_minimum_msat: 65_000,
2394 htlc_maximum_msat: OptionalField::Present(80_000),
2396 fee_proportional_millionths: 0,
2397 excess_data: Vec::new()
2399 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2400 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2401 short_channel_id: 2,
2404 cltv_expiry_delta: 0,
2405 htlc_minimum_msat: 0,
2406 htlc_maximum_msat: OptionalField::Absent,
2408 fee_proportional_millionths: 0,
2409 excess_data: Vec::new()
2411 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2412 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2413 short_channel_id: 4,
2416 cltv_expiry_delta: 0,
2417 htlc_minimum_msat: 0,
2418 htlc_maximum_msat: OptionalField::Absent,
2420 fee_proportional_millionths: 100_000,
2421 excess_data: Vec::new()
2424 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2425 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2426 assert_eq!(route.paths.len(), 1);
2427 assert_eq!(route.paths[0][0].short_channel_id, 12);
2428 let fees = route.paths[0][0].fee_msat;
2429 assert_eq!(fees, 5_000);
2431 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2432 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2433 // the other channel.
2434 assert_eq!(route.paths.len(), 1);
2435 assert_eq!(route.paths[0][0].short_channel_id, 2);
2436 let fees = route.paths[0][0].fee_msat;
2437 assert_eq!(fees, 5_000);
2441 fn disable_channels_test() {
2442 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2443 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2444 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2445 let scorer = test_utils::TestScorer::with_penalty(0);
2446 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2447 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2449 // // Disable channels 4 and 12 by flags=2
2450 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2451 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2452 short_channel_id: 4,
2454 flags: 2, // to disable
2455 cltv_expiry_delta: 0,
2456 htlc_minimum_msat: 0,
2457 htlc_maximum_msat: OptionalField::Absent,
2459 fee_proportional_millionths: 0,
2460 excess_data: Vec::new()
2462 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2463 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2464 short_channel_id: 12,
2466 flags: 2, // to disable
2467 cltv_expiry_delta: 0,
2468 htlc_minimum_msat: 0,
2469 htlc_maximum_msat: OptionalField::Absent,
2471 fee_proportional_millionths: 0,
2472 excess_data: Vec::new()
2475 // If all the channels require some features we don't understand, route should fail
2476 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) {
2477 assert_eq!(err, "Failed to find a path to the given destination");
2478 } else { panic!(); }
2480 // If we specify a channel to node7, that overrides our local channel view and that gets used
2481 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2482 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();
2483 assert_eq!(route.paths[0].len(), 2);
2485 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2486 assert_eq!(route.paths[0][0].short_channel_id, 42);
2487 assert_eq!(route.paths[0][0].fee_msat, 200);
2488 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2489 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2490 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2492 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2493 assert_eq!(route.paths[0][1].short_channel_id, 13);
2494 assert_eq!(route.paths[0][1].fee_msat, 100);
2495 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2496 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2497 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2501 fn disable_node_test() {
2502 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2503 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2504 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2505 let scorer = test_utils::TestScorer::with_penalty(0);
2506 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2507 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2509 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2510 let mut unknown_features = NodeFeatures::known();
2511 unknown_features.set_unknown_feature_required();
2512 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2513 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2514 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2516 // If all nodes require some features we don't understand, route should fail
2517 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) {
2518 assert_eq!(err, "Failed to find a path to the given destination");
2519 } else { panic!(); }
2521 // If we specify a channel to node7, that overrides our local channel view and that gets used
2522 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2523 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();
2524 assert_eq!(route.paths[0].len(), 2);
2526 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2527 assert_eq!(route.paths[0][0].short_channel_id, 42);
2528 assert_eq!(route.paths[0][0].fee_msat, 200);
2529 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2530 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2531 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2533 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2534 assert_eq!(route.paths[0][1].short_channel_id, 13);
2535 assert_eq!(route.paths[0][1].fee_msat, 100);
2536 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2537 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2538 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2540 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2541 // naively) assume that the user checked the feature bits on the invoice, which override
2542 // the node_announcement.
2546 fn our_chans_test() {
2547 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2548 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2549 let scorer = test_utils::TestScorer::with_penalty(0);
2550 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2551 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2553 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2554 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2555 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2556 assert_eq!(route.paths[0].len(), 3);
2558 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2559 assert_eq!(route.paths[0][0].short_channel_id, 2);
2560 assert_eq!(route.paths[0][0].fee_msat, 200);
2561 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2562 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2563 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2565 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2566 assert_eq!(route.paths[0][1].short_channel_id, 4);
2567 assert_eq!(route.paths[0][1].fee_msat, 100);
2568 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2569 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2570 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2572 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2573 assert_eq!(route.paths[0][2].short_channel_id, 3);
2574 assert_eq!(route.paths[0][2].fee_msat, 100);
2575 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2576 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2577 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2579 // If we specify a channel to node7, that overrides our local channel view and that gets used
2580 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2581 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2582 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();
2583 assert_eq!(route.paths[0].len(), 2);
2585 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2586 assert_eq!(route.paths[0][0].short_channel_id, 42);
2587 assert_eq!(route.paths[0][0].fee_msat, 200);
2588 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2589 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2590 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2592 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2593 assert_eq!(route.paths[0][1].short_channel_id, 13);
2594 assert_eq!(route.paths[0][1].fee_msat, 100);
2595 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2596 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2597 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2600 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2601 let zero_fees = RoutingFees {
2603 proportional_millionths: 0,
2605 vec![RouteHint(vec![RouteHintHop {
2606 src_node_id: nodes[3],
2607 short_channel_id: 8,
2609 cltv_expiry_delta: (8 << 4) | 1,
2610 htlc_minimum_msat: None,
2611 htlc_maximum_msat: None,
2613 ]), RouteHint(vec![RouteHintHop {
2614 src_node_id: nodes[4],
2615 short_channel_id: 9,
2618 proportional_millionths: 0,
2620 cltv_expiry_delta: (9 << 4) | 1,
2621 htlc_minimum_msat: None,
2622 htlc_maximum_msat: None,
2623 }]), RouteHint(vec![RouteHintHop {
2624 src_node_id: nodes[5],
2625 short_channel_id: 10,
2627 cltv_expiry_delta: (10 << 4) | 1,
2628 htlc_minimum_msat: None,
2629 htlc_maximum_msat: None,
2633 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2634 let zero_fees = RoutingFees {
2636 proportional_millionths: 0,
2638 vec![RouteHint(vec![RouteHintHop {
2639 src_node_id: nodes[2],
2640 short_channel_id: 5,
2643 proportional_millionths: 0,
2645 cltv_expiry_delta: (5 << 4) | 1,
2646 htlc_minimum_msat: None,
2647 htlc_maximum_msat: None,
2649 src_node_id: nodes[3],
2650 short_channel_id: 8,
2652 cltv_expiry_delta: (8 << 4) | 1,
2653 htlc_minimum_msat: None,
2654 htlc_maximum_msat: None,
2656 ]), RouteHint(vec![RouteHintHop {
2657 src_node_id: nodes[4],
2658 short_channel_id: 9,
2661 proportional_millionths: 0,
2663 cltv_expiry_delta: (9 << 4) | 1,
2664 htlc_minimum_msat: None,
2665 htlc_maximum_msat: None,
2666 }]), RouteHint(vec![RouteHintHop {
2667 src_node_id: nodes[5],
2668 short_channel_id: 10,
2670 cltv_expiry_delta: (10 << 4) | 1,
2671 htlc_minimum_msat: None,
2672 htlc_maximum_msat: None,
2677 fn partial_route_hint_test() {
2678 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2679 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2680 let scorer = test_utils::TestScorer::with_penalty(0);
2681 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2682 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2684 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2685 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2686 // RouteHint may be partially used by the algo to build the best path.
2688 // First check that last hop can't have its source as the payee.
2689 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2690 src_node_id: nodes[6],
2691 short_channel_id: 8,
2694 proportional_millionths: 0,
2696 cltv_expiry_delta: (8 << 4) | 1,
2697 htlc_minimum_msat: None,
2698 htlc_maximum_msat: None,
2701 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2702 invalid_last_hops.push(invalid_last_hop);
2704 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2705 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) {
2706 assert_eq!(err, "Route hint cannot have the payee as the source.");
2707 } else { panic!(); }
2710 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
2711 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2712 assert_eq!(route.paths[0].len(), 5);
2714 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2715 assert_eq!(route.paths[0][0].short_channel_id, 2);
2716 assert_eq!(route.paths[0][0].fee_msat, 100);
2717 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2718 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2719 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2721 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2722 assert_eq!(route.paths[0][1].short_channel_id, 4);
2723 assert_eq!(route.paths[0][1].fee_msat, 0);
2724 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2725 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2726 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2728 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2729 assert_eq!(route.paths[0][2].short_channel_id, 6);
2730 assert_eq!(route.paths[0][2].fee_msat, 0);
2731 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2732 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2733 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2735 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2736 assert_eq!(route.paths[0][3].short_channel_id, 11);
2737 assert_eq!(route.paths[0][3].fee_msat, 0);
2738 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2739 // If we have a peer in the node map, we'll use their features here since we don't have
2740 // a way of figuring out their features from the invoice:
2741 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2742 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2744 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2745 assert_eq!(route.paths[0][4].short_channel_id, 8);
2746 assert_eq!(route.paths[0][4].fee_msat, 100);
2747 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2748 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2749 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2752 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2753 let zero_fees = RoutingFees {
2755 proportional_millionths: 0,
2757 vec![RouteHint(vec![RouteHintHop {
2758 src_node_id: nodes[3],
2759 short_channel_id: 8,
2761 cltv_expiry_delta: (8 << 4) | 1,
2762 htlc_minimum_msat: None,
2763 htlc_maximum_msat: None,
2764 }]), RouteHint(vec![
2766 ]), RouteHint(vec![RouteHintHop {
2767 src_node_id: nodes[5],
2768 short_channel_id: 10,
2770 cltv_expiry_delta: (10 << 4) | 1,
2771 htlc_minimum_msat: None,
2772 htlc_maximum_msat: None,
2777 fn ignores_empty_last_hops_test() {
2778 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2779 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2780 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
2781 let scorer = test_utils::TestScorer::with_penalty(0);
2782 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2783 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2785 // Test handling of an empty RouteHint passed in Invoice.
2787 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2788 assert_eq!(route.paths[0].len(), 5);
2790 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2791 assert_eq!(route.paths[0][0].short_channel_id, 2);
2792 assert_eq!(route.paths[0][0].fee_msat, 100);
2793 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2794 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2795 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2797 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2798 assert_eq!(route.paths[0][1].short_channel_id, 4);
2799 assert_eq!(route.paths[0][1].fee_msat, 0);
2800 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
2801 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2802 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2804 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
2805 assert_eq!(route.paths[0][2].short_channel_id, 6);
2806 assert_eq!(route.paths[0][2].fee_msat, 0);
2807 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
2808 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
2809 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
2811 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
2812 assert_eq!(route.paths[0][3].short_channel_id, 11);
2813 assert_eq!(route.paths[0][3].fee_msat, 0);
2814 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
2815 // If we have a peer in the node map, we'll use their features here since we don't have
2816 // a way of figuring out their features from the invoice:
2817 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
2818 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
2820 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
2821 assert_eq!(route.paths[0][4].short_channel_id, 8);
2822 assert_eq!(route.paths[0][4].fee_msat, 100);
2823 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
2824 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2825 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2828 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
2830 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
2831 let zero_fees = RoutingFees {
2833 proportional_millionths: 0,
2835 vec![RouteHint(vec![RouteHintHop {
2836 src_node_id: hint_hops[0],
2837 short_channel_id: 0xff00,
2840 proportional_millionths: 0,
2842 cltv_expiry_delta: (5 << 4) | 1,
2843 htlc_minimum_msat: None,
2844 htlc_maximum_msat: None,
2846 src_node_id: hint_hops[1],
2847 short_channel_id: 0xff01,
2849 cltv_expiry_delta: (8 << 4) | 1,
2850 htlc_minimum_msat: None,
2851 htlc_maximum_msat: None,
2856 fn multi_hint_last_hops_test() {
2857 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2858 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2859 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
2860 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2861 let scorer = test_utils::TestScorer::with_penalty(0);
2862 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2863 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2864 // Test through channels 2, 3, 0xff00, 0xff01.
2865 // Test shows that multiple hop hints are considered.
2867 // Disabling channels 6 & 7 by flags=2
2868 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2869 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2870 short_channel_id: 6,
2872 flags: 2, // to disable
2873 cltv_expiry_delta: 0,
2874 htlc_minimum_msat: 0,
2875 htlc_maximum_msat: OptionalField::Absent,
2877 fee_proportional_millionths: 0,
2878 excess_data: Vec::new()
2880 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2881 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2882 short_channel_id: 7,
2884 flags: 2, // to disable
2885 cltv_expiry_delta: 0,
2886 htlc_minimum_msat: 0,
2887 htlc_maximum_msat: OptionalField::Absent,
2889 fee_proportional_millionths: 0,
2890 excess_data: Vec::new()
2893 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2894 assert_eq!(route.paths[0].len(), 4);
2896 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2897 assert_eq!(route.paths[0][0].short_channel_id, 2);
2898 assert_eq!(route.paths[0][0].fee_msat, 200);
2899 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2900 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2901 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2903 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2904 assert_eq!(route.paths[0][1].short_channel_id, 4);
2905 assert_eq!(route.paths[0][1].fee_msat, 100);
2906 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2907 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2908 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2910 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
2911 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
2912 assert_eq!(route.paths[0][2].fee_msat, 0);
2913 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2914 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
2915 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2917 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2918 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
2919 assert_eq!(route.paths[0][3].fee_msat, 100);
2920 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2921 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2922 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2926 fn private_multi_hint_last_hops_test() {
2927 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
2928 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2930 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
2931 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
2933 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
2934 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
2935 let scorer = test_utils::TestScorer::with_penalty(0);
2936 // Test through channels 2, 3, 0xff00, 0xff01.
2937 // Test shows that multiple hop hints are considered.
2939 // Disabling channels 6 & 7 by flags=2
2940 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2941 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2942 short_channel_id: 6,
2944 flags: 2, // to disable
2945 cltv_expiry_delta: 0,
2946 htlc_minimum_msat: 0,
2947 htlc_maximum_msat: OptionalField::Absent,
2949 fee_proportional_millionths: 0,
2950 excess_data: Vec::new()
2952 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2953 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2954 short_channel_id: 7,
2956 flags: 2, // to disable
2957 cltv_expiry_delta: 0,
2958 htlc_minimum_msat: 0,
2959 htlc_maximum_msat: OptionalField::Absent,
2961 fee_proportional_millionths: 0,
2962 excess_data: Vec::new()
2965 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
2966 assert_eq!(route.paths[0].len(), 4);
2968 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2969 assert_eq!(route.paths[0][0].short_channel_id, 2);
2970 assert_eq!(route.paths[0][0].fee_msat, 200);
2971 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
2972 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2973 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2975 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2976 assert_eq!(route.paths[0][1].short_channel_id, 4);
2977 assert_eq!(route.paths[0][1].fee_msat, 100);
2978 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
2979 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2980 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2982 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
2983 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
2984 assert_eq!(route.paths[0][2].fee_msat, 0);
2985 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
2986 assert_eq!(route.paths[0][2].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2987 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2989 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
2990 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
2991 assert_eq!(route.paths[0][3].fee_msat, 100);
2992 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
2993 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
2994 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
2997 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2998 let zero_fees = RoutingFees {
3000 proportional_millionths: 0,
3002 vec![RouteHint(vec![RouteHintHop {
3003 src_node_id: nodes[4],
3004 short_channel_id: 11,
3006 cltv_expiry_delta: (11 << 4) | 1,
3007 htlc_minimum_msat: None,
3008 htlc_maximum_msat: None,
3010 src_node_id: nodes[3],
3011 short_channel_id: 8,
3013 cltv_expiry_delta: (8 << 4) | 1,
3014 htlc_minimum_msat: None,
3015 htlc_maximum_msat: None,
3016 }]), RouteHint(vec![RouteHintHop {
3017 src_node_id: nodes[4],
3018 short_channel_id: 9,
3021 proportional_millionths: 0,
3023 cltv_expiry_delta: (9 << 4) | 1,
3024 htlc_minimum_msat: None,
3025 htlc_maximum_msat: None,
3026 }]), RouteHint(vec![RouteHintHop {
3027 src_node_id: nodes[5],
3028 short_channel_id: 10,
3030 cltv_expiry_delta: (10 << 4) | 1,
3031 htlc_minimum_msat: None,
3032 htlc_maximum_msat: None,
3037 fn last_hops_with_public_channel_test() {
3038 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3039 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3040 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3041 let scorer = test_utils::TestScorer::with_penalty(0);
3042 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3043 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3044 // This test shows that public routes can be present in the invoice
3045 // which would be handled in the same manner.
3047 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3048 assert_eq!(route.paths[0].len(), 5);
3050 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3051 assert_eq!(route.paths[0][0].short_channel_id, 2);
3052 assert_eq!(route.paths[0][0].fee_msat, 100);
3053 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3054 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3055 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3057 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3058 assert_eq!(route.paths[0][1].short_channel_id, 4);
3059 assert_eq!(route.paths[0][1].fee_msat, 0);
3060 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3061 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3062 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3064 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3065 assert_eq!(route.paths[0][2].short_channel_id, 6);
3066 assert_eq!(route.paths[0][2].fee_msat, 0);
3067 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3068 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3069 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3071 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3072 assert_eq!(route.paths[0][3].short_channel_id, 11);
3073 assert_eq!(route.paths[0][3].fee_msat, 0);
3074 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3075 // If we have a peer in the node map, we'll use their features here since we don't have
3076 // a way of figuring out their features from the invoice:
3077 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3078 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3080 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3081 assert_eq!(route.paths[0][4].short_channel_id, 8);
3082 assert_eq!(route.paths[0][4].fee_msat, 100);
3083 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3084 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3085 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3089 fn our_chans_last_hop_connect_test() {
3090 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3091 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3092 let scorer = test_utils::TestScorer::with_penalty(0);
3093 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3094 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3096 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3097 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3098 let mut last_hops = last_hops(&nodes);
3099 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3100 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();
3101 assert_eq!(route.paths[0].len(), 2);
3103 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3104 assert_eq!(route.paths[0][0].short_channel_id, 42);
3105 assert_eq!(route.paths[0][0].fee_msat, 0);
3106 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3107 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3108 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3110 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3111 assert_eq!(route.paths[0][1].short_channel_id, 8);
3112 assert_eq!(route.paths[0][1].fee_msat, 100);
3113 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3114 assert_eq!(route.paths[0][1].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3115 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3117 last_hops[0].0[0].fees.base_msat = 1000;
3119 // Revert to via 6 as the fee on 8 goes up
3120 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3121 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3122 assert_eq!(route.paths[0].len(), 4);
3124 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3125 assert_eq!(route.paths[0][0].short_channel_id, 2);
3126 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3127 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3128 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3129 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3131 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3132 assert_eq!(route.paths[0][1].short_channel_id, 4);
3133 assert_eq!(route.paths[0][1].fee_msat, 100);
3134 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3135 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3136 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3138 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3139 assert_eq!(route.paths[0][2].short_channel_id, 7);
3140 assert_eq!(route.paths[0][2].fee_msat, 0);
3141 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3142 // If we have a peer in the node map, we'll use their features here since we don't have
3143 // a way of figuring out their features from the invoice:
3144 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3145 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3147 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3148 assert_eq!(route.paths[0][3].short_channel_id, 10);
3149 assert_eq!(route.paths[0][3].fee_msat, 100);
3150 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3151 assert_eq!(route.paths[0][3].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3152 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3154 // ...but still use 8 for larger payments as 6 has a variable feerate
3155 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3156 assert_eq!(route.paths[0].len(), 5);
3158 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3159 assert_eq!(route.paths[0][0].short_channel_id, 2);
3160 assert_eq!(route.paths[0][0].fee_msat, 3000);
3161 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3162 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3163 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3165 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3166 assert_eq!(route.paths[0][1].short_channel_id, 4);
3167 assert_eq!(route.paths[0][1].fee_msat, 0);
3168 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3169 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3170 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3172 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3173 assert_eq!(route.paths[0][2].short_channel_id, 6);
3174 assert_eq!(route.paths[0][2].fee_msat, 0);
3175 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3176 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3177 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3179 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3180 assert_eq!(route.paths[0][3].short_channel_id, 11);
3181 assert_eq!(route.paths[0][3].fee_msat, 1000);
3182 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3183 // If we have a peer in the node map, we'll use their features here since we don't have
3184 // a way of figuring out their features from the invoice:
3185 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3186 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3188 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3189 assert_eq!(route.paths[0][4].short_channel_id, 8);
3190 assert_eq!(route.paths[0][4].fee_msat, 2000);
3191 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3192 assert_eq!(route.paths[0][4].node_features.le_flags(), &Vec::<u8>::new()); // We dont pass flags in from invoices yet
3193 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3196 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> {
3197 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3198 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3199 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3201 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3202 let last_hops = RouteHint(vec![RouteHintHop {
3203 src_node_id: middle_node_id,
3204 short_channel_id: 8,
3207 proportional_millionths: last_hop_fee_prop,
3209 cltv_expiry_delta: (8 << 4) | 1,
3210 htlc_minimum_msat: None,
3211 htlc_maximum_msat: last_hop_htlc_max,
3213 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3214 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3215 let scorer = test_utils::TestScorer::with_penalty(0);
3216 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3217 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3218 get_route(&source_node_id, &payment_params, &NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()).read_only(),
3219 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes)
3223 fn unannounced_path_test() {
3224 // We should be able to send a payment to a destination without any help of a routing graph
3225 // if we have a channel with a common counterparty that appears in the first and last hop
3227 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3229 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3230 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3231 assert_eq!(route.paths[0].len(), 2);
3233 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3234 assert_eq!(route.paths[0][0].short_channel_id, 42);
3235 assert_eq!(route.paths[0][0].fee_msat, 1001);
3236 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3237 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3238 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3240 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3241 assert_eq!(route.paths[0][1].short_channel_id, 8);
3242 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3243 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3244 assert_eq!(route.paths[0][1].node_features.le_flags(), &[0; 0]); // We dont pass flags in from invoices yet
3245 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3249 fn overflow_unannounced_path_test_liquidity_underflow() {
3250 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3251 // the last-hop had a fee which overflowed a u64, we'd panic.
3252 // This was due to us adding the first-hop from us unconditionally, causing us to think
3253 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3254 // In this test, we previously hit a subtraction underflow due to having less available
3255 // liquidity at the last hop than 0.
3256 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());
3260 fn overflow_unannounced_path_test_feerate_overflow() {
3261 // This tests for the same case as above, except instead of hitting a subtraction
3262 // underflow, we hit a case where the fee charged at a hop overflowed.
3263 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());
3267 fn available_amount_while_routing_test() {
3268 // Tests whether we choose the correct available channel amount while routing.
3270 let (secp_ctx, network_graph, mut net_graph_msg_handler, chain_monitor, logger) = build_graph();
3271 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3272 let scorer = test_utils::TestScorer::with_penalty(0);
3273 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3274 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3275 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3277 // We will use a simple single-path route from
3278 // our node to node2 via node0: channels {1, 3}.
3280 // First disable all other paths.
3281 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3282 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3283 short_channel_id: 2,
3286 cltv_expiry_delta: 0,
3287 htlc_minimum_msat: 0,
3288 htlc_maximum_msat: OptionalField::Present(100_000),
3290 fee_proportional_millionths: 0,
3291 excess_data: Vec::new()
3293 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3294 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3295 short_channel_id: 12,
3298 cltv_expiry_delta: 0,
3299 htlc_minimum_msat: 0,
3300 htlc_maximum_msat: OptionalField::Present(100_000),
3302 fee_proportional_millionths: 0,
3303 excess_data: Vec::new()
3306 // Make the first channel (#1) very permissive,
3307 // and we will be testing all limits on the second channel.
3308 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3309 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3310 short_channel_id: 1,
3313 cltv_expiry_delta: 0,
3314 htlc_minimum_msat: 0,
3315 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3317 fee_proportional_millionths: 0,
3318 excess_data: Vec::new()
3321 // First, let's see if routing works if we have absolutely no idea about the available amount.
3322 // In this case, it should be set to 250_000 sats.
3323 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3324 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3325 short_channel_id: 3,
3328 cltv_expiry_delta: 0,
3329 htlc_minimum_msat: 0,
3330 htlc_maximum_msat: OptionalField::Absent,
3332 fee_proportional_millionths: 0,
3333 excess_data: Vec::new()
3337 // Attempt to route more than available results in a failure.
3338 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3339 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3340 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3341 } else { panic!(); }
3345 // Now, attempt to route an exact amount we have should be fine.
3346 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();
3347 assert_eq!(route.paths.len(), 1);
3348 let path = route.paths.last().unwrap();
3349 assert_eq!(path.len(), 2);
3350 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3351 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3354 // Check that setting outbound_capacity_msat in first_hops limits the channels.
3355 // Disable channel #1 and use another first hop.
3356 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3357 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3358 short_channel_id: 1,
3361 cltv_expiry_delta: 0,
3362 htlc_minimum_msat: 0,
3363 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3365 fee_proportional_millionths: 0,
3366 excess_data: Vec::new()
3369 // Now, limit the first_hop by the outbound_capacity_msat of 200_000 sats.
3370 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3373 // Attempt to route more than available results in a failure.
3374 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3375 &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) {
3376 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3377 } else { panic!(); }
3381 // Now, attempt to route an exact amount we have should be fine.
3382 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();
3383 assert_eq!(route.paths.len(), 1);
3384 let path = route.paths.last().unwrap();
3385 assert_eq!(path.len(), 2);
3386 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3387 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3390 // Enable channel #1 back.
3391 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3392 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3393 short_channel_id: 1,
3396 cltv_expiry_delta: 0,
3397 htlc_minimum_msat: 0,
3398 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3400 fee_proportional_millionths: 0,
3401 excess_data: Vec::new()
3405 // Now let's see if routing works if we know only htlc_maximum_msat.
3406 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3407 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3408 short_channel_id: 3,
3411 cltv_expiry_delta: 0,
3412 htlc_minimum_msat: 0,
3413 htlc_maximum_msat: OptionalField::Present(15_000),
3415 fee_proportional_millionths: 0,
3416 excess_data: Vec::new()
3420 // Attempt to route more than available results in a failure.
3421 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3422 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3423 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3424 } else { panic!(); }
3428 // Now, attempt to route an exact amount we have should be fine.
3429 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3430 assert_eq!(route.paths.len(), 1);
3431 let path = route.paths.last().unwrap();
3432 assert_eq!(path.len(), 2);
3433 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3434 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3437 // Now let's see if routing works if we know only capacity from the UTXO.
3439 // We can't change UTXO capacity on the fly, so we'll disable
3440 // the existing channel and add another one with the capacity we need.
3441 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3442 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3443 short_channel_id: 3,
3446 cltv_expiry_delta: 0,
3447 htlc_minimum_msat: 0,
3448 htlc_maximum_msat: OptionalField::Absent,
3450 fee_proportional_millionths: 0,
3451 excess_data: Vec::new()
3454 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3455 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3456 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3457 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3458 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3460 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3461 net_graph_msg_handler.add_chain_access(Some(chain_monitor));
3463 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3464 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3465 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3466 short_channel_id: 333,
3469 cltv_expiry_delta: (3 << 4) | 1,
3470 htlc_minimum_msat: 0,
3471 htlc_maximum_msat: OptionalField::Absent,
3473 fee_proportional_millionths: 0,
3474 excess_data: Vec::new()
3476 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3477 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3478 short_channel_id: 333,
3481 cltv_expiry_delta: (3 << 4) | 2,
3482 htlc_minimum_msat: 0,
3483 htlc_maximum_msat: OptionalField::Absent,
3485 fee_proportional_millionths: 0,
3486 excess_data: Vec::new()
3490 // Attempt to route more than available results in a failure.
3491 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3492 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3493 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3494 } else { panic!(); }
3498 // Now, attempt to route an exact amount we have should be fine.
3499 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3500 assert_eq!(route.paths.len(), 1);
3501 let path = route.paths.last().unwrap();
3502 assert_eq!(path.len(), 2);
3503 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3504 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3507 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3508 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3509 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3510 short_channel_id: 333,
3513 cltv_expiry_delta: 0,
3514 htlc_minimum_msat: 0,
3515 htlc_maximum_msat: OptionalField::Present(10_000),
3517 fee_proportional_millionths: 0,
3518 excess_data: Vec::new()
3522 // Attempt to route more than available results in a failure.
3523 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3524 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3525 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3526 } else { panic!(); }
3530 // Now, attempt to route an exact amount we have should be fine.
3531 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3532 assert_eq!(route.paths.len(), 1);
3533 let path = route.paths.last().unwrap();
3534 assert_eq!(path.len(), 2);
3535 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3536 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3541 fn available_liquidity_last_hop_test() {
3542 // Check that available liquidity properly limits the path even when only
3543 // one of the latter hops is limited.
3544 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3545 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3546 let scorer = test_utils::TestScorer::with_penalty(0);
3547 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3548 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3549 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3551 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3552 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3553 // Total capacity: 50 sats.
3555 // Disable other potential paths.
3556 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3557 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3558 short_channel_id: 2,
3561 cltv_expiry_delta: 0,
3562 htlc_minimum_msat: 0,
3563 htlc_maximum_msat: OptionalField::Present(100_000),
3565 fee_proportional_millionths: 0,
3566 excess_data: Vec::new()
3568 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3569 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3570 short_channel_id: 7,
3573 cltv_expiry_delta: 0,
3574 htlc_minimum_msat: 0,
3575 htlc_maximum_msat: OptionalField::Present(100_000),
3577 fee_proportional_millionths: 0,
3578 excess_data: Vec::new()
3583 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3584 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3585 short_channel_id: 12,
3588 cltv_expiry_delta: 0,
3589 htlc_minimum_msat: 0,
3590 htlc_maximum_msat: OptionalField::Present(100_000),
3592 fee_proportional_millionths: 0,
3593 excess_data: Vec::new()
3595 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3596 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3597 short_channel_id: 13,
3600 cltv_expiry_delta: 0,
3601 htlc_minimum_msat: 0,
3602 htlc_maximum_msat: OptionalField::Present(100_000),
3604 fee_proportional_millionths: 0,
3605 excess_data: Vec::new()
3608 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3609 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3610 short_channel_id: 6,
3613 cltv_expiry_delta: 0,
3614 htlc_minimum_msat: 0,
3615 htlc_maximum_msat: OptionalField::Present(50_000),
3617 fee_proportional_millionths: 0,
3618 excess_data: Vec::new()
3620 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3621 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3622 short_channel_id: 11,
3625 cltv_expiry_delta: 0,
3626 htlc_minimum_msat: 0,
3627 htlc_maximum_msat: OptionalField::Present(100_000),
3629 fee_proportional_millionths: 0,
3630 excess_data: Vec::new()
3633 // Attempt to route more than available results in a failure.
3634 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3635 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3636 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3637 } else { panic!(); }
3641 // Now, attempt to route 49 sats (just a bit below the capacity).
3642 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3643 assert_eq!(route.paths.len(), 1);
3644 let mut total_amount_paid_msat = 0;
3645 for path in &route.paths {
3646 assert_eq!(path.len(), 4);
3647 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3648 total_amount_paid_msat += path.last().unwrap().fee_msat;
3650 assert_eq!(total_amount_paid_msat, 49_000);
3654 // Attempt to route an exact amount is also fine
3655 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3656 assert_eq!(route.paths.len(), 1);
3657 let mut total_amount_paid_msat = 0;
3658 for path in &route.paths {
3659 assert_eq!(path.len(), 4);
3660 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3661 total_amount_paid_msat += path.last().unwrap().fee_msat;
3663 assert_eq!(total_amount_paid_msat, 50_000);
3668 fn ignore_fee_first_hop_test() {
3669 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3670 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3671 let scorer = test_utils::TestScorer::with_penalty(0);
3672 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3673 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3674 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3676 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3677 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3678 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3679 short_channel_id: 1,
3682 cltv_expiry_delta: 0,
3683 htlc_minimum_msat: 0,
3684 htlc_maximum_msat: OptionalField::Present(100_000),
3685 fee_base_msat: 1_000_000,
3686 fee_proportional_millionths: 0,
3687 excess_data: Vec::new()
3689 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3690 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3691 short_channel_id: 3,
3694 cltv_expiry_delta: 0,
3695 htlc_minimum_msat: 0,
3696 htlc_maximum_msat: OptionalField::Present(50_000),
3698 fee_proportional_millionths: 0,
3699 excess_data: Vec::new()
3703 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3704 assert_eq!(route.paths.len(), 1);
3705 let mut total_amount_paid_msat = 0;
3706 for path in &route.paths {
3707 assert_eq!(path.len(), 2);
3708 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3709 total_amount_paid_msat += path.last().unwrap().fee_msat;
3711 assert_eq!(total_amount_paid_msat, 50_000);
3716 fn simple_mpp_route_test() {
3717 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3718 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3719 let scorer = test_utils::TestScorer::with_penalty(0);
3720 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3721 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3722 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3724 // We need a route consisting of 3 paths:
3725 // From our node to node2 via node0, node7, node1 (three paths one hop each).
3726 // To achieve this, the amount being transferred should be around
3727 // the total capacity of these 3 paths.
3729 // First, we set limits on these (previously unlimited) channels.
3730 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
3732 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3733 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3734 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3735 short_channel_id: 1,
3738 cltv_expiry_delta: 0,
3739 htlc_minimum_msat: 0,
3740 htlc_maximum_msat: OptionalField::Present(100_000),
3742 fee_proportional_millionths: 0,
3743 excess_data: Vec::new()
3745 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3746 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3747 short_channel_id: 3,
3750 cltv_expiry_delta: 0,
3751 htlc_minimum_msat: 0,
3752 htlc_maximum_msat: OptionalField::Present(50_000),
3754 fee_proportional_millionths: 0,
3755 excess_data: Vec::new()
3758 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
3759 // (total limit 60).
3760 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3761 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3762 short_channel_id: 12,
3765 cltv_expiry_delta: 0,
3766 htlc_minimum_msat: 0,
3767 htlc_maximum_msat: OptionalField::Present(60_000),
3769 fee_proportional_millionths: 0,
3770 excess_data: Vec::new()
3772 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3773 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3774 short_channel_id: 13,
3777 cltv_expiry_delta: 0,
3778 htlc_minimum_msat: 0,
3779 htlc_maximum_msat: OptionalField::Present(60_000),
3781 fee_proportional_millionths: 0,
3782 excess_data: Vec::new()
3785 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
3786 // (total capacity 180 sats).
3787 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3788 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3789 short_channel_id: 2,
3792 cltv_expiry_delta: 0,
3793 htlc_minimum_msat: 0,
3794 htlc_maximum_msat: OptionalField::Present(200_000),
3796 fee_proportional_millionths: 0,
3797 excess_data: Vec::new()
3799 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
3800 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3801 short_channel_id: 4,
3804 cltv_expiry_delta: 0,
3805 htlc_minimum_msat: 0,
3806 htlc_maximum_msat: OptionalField::Present(180_000),
3808 fee_proportional_millionths: 0,
3809 excess_data: Vec::new()
3813 // Attempt to route more than available results in a failure.
3814 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3815 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3816 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3817 } else { panic!(); }
3821 // Now, attempt to route 250 sats (just a bit below the capacity).
3822 // Our algorithm should provide us with these 3 paths.
3823 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3824 assert_eq!(route.paths.len(), 3);
3825 let mut total_amount_paid_msat = 0;
3826 for path in &route.paths {
3827 assert_eq!(path.len(), 2);
3828 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3829 total_amount_paid_msat += path.last().unwrap().fee_msat;
3831 assert_eq!(total_amount_paid_msat, 250_000);
3835 // Attempt to route an exact amount is also fine
3836 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3837 assert_eq!(route.paths.len(), 3);
3838 let mut total_amount_paid_msat = 0;
3839 for path in &route.paths {
3840 assert_eq!(path.len(), 2);
3841 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3842 total_amount_paid_msat += path.last().unwrap().fee_msat;
3844 assert_eq!(total_amount_paid_msat, 290_000);
3849 fn long_mpp_route_test() {
3850 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
3851 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3852 let scorer = test_utils::TestScorer::with_penalty(0);
3853 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3854 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3855 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3857 // We need a route consisting of 3 paths:
3858 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
3859 // Note that these paths overlap (channels 5, 12, 13).
3860 // We will route 300 sats.
3861 // Each path will have 100 sats capacity, those channels which
3862 // are used twice will have 200 sats capacity.
3864 // Disable other potential paths.
3865 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3866 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3867 short_channel_id: 2,
3870 cltv_expiry_delta: 0,
3871 htlc_minimum_msat: 0,
3872 htlc_maximum_msat: OptionalField::Present(100_000),
3874 fee_proportional_millionths: 0,
3875 excess_data: Vec::new()
3877 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3878 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3879 short_channel_id: 7,
3882 cltv_expiry_delta: 0,
3883 htlc_minimum_msat: 0,
3884 htlc_maximum_msat: OptionalField::Present(100_000),
3886 fee_proportional_millionths: 0,
3887 excess_data: Vec::new()
3890 // Path via {node0, node2} is channels {1, 3, 5}.
3891 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3892 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3893 short_channel_id: 1,
3896 cltv_expiry_delta: 0,
3897 htlc_minimum_msat: 0,
3898 htlc_maximum_msat: OptionalField::Present(100_000),
3900 fee_proportional_millionths: 0,
3901 excess_data: Vec::new()
3903 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3904 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3905 short_channel_id: 3,
3908 cltv_expiry_delta: 0,
3909 htlc_minimum_msat: 0,
3910 htlc_maximum_msat: OptionalField::Present(100_000),
3912 fee_proportional_millionths: 0,
3913 excess_data: Vec::new()
3916 // Capacity of 200 sats because this channel will be used by 3rd path as well.
3917 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
3918 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3919 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3920 short_channel_id: 5,
3923 cltv_expiry_delta: 0,
3924 htlc_minimum_msat: 0,
3925 htlc_maximum_msat: OptionalField::Present(200_000),
3927 fee_proportional_millionths: 0,
3928 excess_data: Vec::new()
3931 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3932 // Add 100 sats to the capacities of {12, 13}, because these channels
3933 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
3934 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3935 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3936 short_channel_id: 12,
3939 cltv_expiry_delta: 0,
3940 htlc_minimum_msat: 0,
3941 htlc_maximum_msat: OptionalField::Present(200_000),
3943 fee_proportional_millionths: 0,
3944 excess_data: Vec::new()
3946 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3947 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3948 short_channel_id: 13,
3951 cltv_expiry_delta: 0,
3952 htlc_minimum_msat: 0,
3953 htlc_maximum_msat: OptionalField::Present(200_000),
3955 fee_proportional_millionths: 0,
3956 excess_data: Vec::new()
3959 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3960 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3961 short_channel_id: 6,
3964 cltv_expiry_delta: 0,
3965 htlc_minimum_msat: 0,
3966 htlc_maximum_msat: OptionalField::Present(100_000),
3968 fee_proportional_millionths: 0,
3969 excess_data: Vec::new()
3971 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3972 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3973 short_channel_id: 11,
3976 cltv_expiry_delta: 0,
3977 htlc_minimum_msat: 0,
3978 htlc_maximum_msat: OptionalField::Present(100_000),
3980 fee_proportional_millionths: 0,
3981 excess_data: Vec::new()
3984 // Path via {node7, node2} is channels {12, 13, 5}.
3985 // We already limited them to 200 sats (they are used twice for 100 sats).
3986 // Nothing to do here.
3989 // Attempt to route more than available results in a failure.
3990 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3991 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3992 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3993 } else { panic!(); }
3997 // Now, attempt to route 300 sats (exact amount we can route).
3998 // Our algorithm should provide us with these 3 paths, 100 sats each.
3999 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4000 assert_eq!(route.paths.len(), 3);
4002 let mut total_amount_paid_msat = 0;
4003 for path in &route.paths {
4004 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4005 total_amount_paid_msat += path.last().unwrap().fee_msat;
4007 assert_eq!(total_amount_paid_msat, 300_000);
4013 fn mpp_cheaper_route_test() {
4014 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4015 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4016 let scorer = test_utils::TestScorer::with_penalty(0);
4017 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4018 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4019 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4021 // This test checks that if we have two cheaper paths and one more expensive path,
4022 // so that liquidity-wise any 2 of 3 combination is sufficient,
4023 // two cheaper paths will be taken.
4024 // These paths have equal available liquidity.
4026 // We need a combination of 3 paths:
4027 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4028 // Note that these paths overlap (channels 5, 12, 13).
4029 // Each path will have 100 sats capacity, those channels which
4030 // are used twice will have 200 sats capacity.
4032 // Disable other potential paths.
4033 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4034 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4035 short_channel_id: 2,
4038 cltv_expiry_delta: 0,
4039 htlc_minimum_msat: 0,
4040 htlc_maximum_msat: OptionalField::Present(100_000),
4042 fee_proportional_millionths: 0,
4043 excess_data: Vec::new()
4045 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4046 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4047 short_channel_id: 7,
4050 cltv_expiry_delta: 0,
4051 htlc_minimum_msat: 0,
4052 htlc_maximum_msat: OptionalField::Present(100_000),
4054 fee_proportional_millionths: 0,
4055 excess_data: Vec::new()
4058 // Path via {node0, node2} is channels {1, 3, 5}.
4059 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4060 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4061 short_channel_id: 1,
4064 cltv_expiry_delta: 0,
4065 htlc_minimum_msat: 0,
4066 htlc_maximum_msat: OptionalField::Present(100_000),
4068 fee_proportional_millionths: 0,
4069 excess_data: Vec::new()
4071 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4072 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4073 short_channel_id: 3,
4076 cltv_expiry_delta: 0,
4077 htlc_minimum_msat: 0,
4078 htlc_maximum_msat: OptionalField::Present(100_000),
4080 fee_proportional_millionths: 0,
4081 excess_data: Vec::new()
4084 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4085 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4086 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4087 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4088 short_channel_id: 5,
4091 cltv_expiry_delta: 0,
4092 htlc_minimum_msat: 0,
4093 htlc_maximum_msat: OptionalField::Present(200_000),
4095 fee_proportional_millionths: 0,
4096 excess_data: Vec::new()
4099 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4100 // Add 100 sats to the capacities of {12, 13}, because these channels
4101 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4102 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4103 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4104 short_channel_id: 12,
4107 cltv_expiry_delta: 0,
4108 htlc_minimum_msat: 0,
4109 htlc_maximum_msat: OptionalField::Present(200_000),
4111 fee_proportional_millionths: 0,
4112 excess_data: Vec::new()
4114 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4115 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4116 short_channel_id: 13,
4119 cltv_expiry_delta: 0,
4120 htlc_minimum_msat: 0,
4121 htlc_maximum_msat: OptionalField::Present(200_000),
4123 fee_proportional_millionths: 0,
4124 excess_data: Vec::new()
4127 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4128 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4129 short_channel_id: 6,
4132 cltv_expiry_delta: 0,
4133 htlc_minimum_msat: 0,
4134 htlc_maximum_msat: OptionalField::Present(100_000),
4135 fee_base_msat: 1_000,
4136 fee_proportional_millionths: 0,
4137 excess_data: Vec::new()
4139 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4140 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4141 short_channel_id: 11,
4144 cltv_expiry_delta: 0,
4145 htlc_minimum_msat: 0,
4146 htlc_maximum_msat: OptionalField::Present(100_000),
4148 fee_proportional_millionths: 0,
4149 excess_data: Vec::new()
4152 // Path via {node7, node2} is channels {12, 13, 5}.
4153 // We already limited them to 200 sats (they are used twice for 100 sats).
4154 // Nothing to do here.
4157 // Now, attempt to route 180 sats.
4158 // Our algorithm should provide us with these 2 paths.
4159 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4160 assert_eq!(route.paths.len(), 2);
4162 let mut total_value_transferred_msat = 0;
4163 let mut total_paid_msat = 0;
4164 for path in &route.paths {
4165 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4166 total_value_transferred_msat += path.last().unwrap().fee_msat;
4168 total_paid_msat += hop.fee_msat;
4171 // If we paid fee, this would be higher.
4172 assert_eq!(total_value_transferred_msat, 180_000);
4173 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4174 assert_eq!(total_fees_paid, 0);
4179 fn fees_on_mpp_route_test() {
4180 // This test makes sure that MPP algorithm properly takes into account
4181 // fees charged on the channels, by making the fees impactful:
4182 // if the fee is not properly accounted for, the behavior is different.
4183 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4184 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4185 let scorer = test_utils::TestScorer::with_penalty(0);
4186 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4187 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4188 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4190 // We need a route consisting of 2 paths:
4191 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4192 // We will route 200 sats, Each path will have 100 sats capacity.
4194 // This test is not particularly stable: e.g.,
4195 // there's a way to route via {node0, node2, node4}.
4196 // It works while pathfinding is deterministic, but can be broken otherwise.
4197 // It's fine to ignore this concern for now.
4199 // Disable other potential paths.
4200 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4201 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4202 short_channel_id: 2,
4205 cltv_expiry_delta: 0,
4206 htlc_minimum_msat: 0,
4207 htlc_maximum_msat: OptionalField::Present(100_000),
4209 fee_proportional_millionths: 0,
4210 excess_data: Vec::new()
4213 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4214 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4215 short_channel_id: 7,
4218 cltv_expiry_delta: 0,
4219 htlc_minimum_msat: 0,
4220 htlc_maximum_msat: OptionalField::Present(100_000),
4222 fee_proportional_millionths: 0,
4223 excess_data: Vec::new()
4226 // Path via {node0, node2} is channels {1, 3, 5}.
4227 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4228 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4229 short_channel_id: 1,
4232 cltv_expiry_delta: 0,
4233 htlc_minimum_msat: 0,
4234 htlc_maximum_msat: OptionalField::Present(100_000),
4236 fee_proportional_millionths: 0,
4237 excess_data: Vec::new()
4239 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4240 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4241 short_channel_id: 3,
4244 cltv_expiry_delta: 0,
4245 htlc_minimum_msat: 0,
4246 htlc_maximum_msat: OptionalField::Present(100_000),
4248 fee_proportional_millionths: 0,
4249 excess_data: Vec::new()
4252 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4253 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4254 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4255 short_channel_id: 5,
4258 cltv_expiry_delta: 0,
4259 htlc_minimum_msat: 0,
4260 htlc_maximum_msat: OptionalField::Present(100_000),
4262 fee_proportional_millionths: 0,
4263 excess_data: Vec::new()
4266 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4267 // All channels should be 100 sats capacity. But for the fee experiment,
4268 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4269 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4270 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4271 // so no matter how large are other channels,
4272 // the whole path will be limited by 100 sats with just these 2 conditions:
4273 // - channel 12 capacity is 250 sats
4274 // - fee for channel 6 is 150 sats
4275 // Let's test this by enforcing these 2 conditions and removing other limits.
4276 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4277 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4278 short_channel_id: 12,
4281 cltv_expiry_delta: 0,
4282 htlc_minimum_msat: 0,
4283 htlc_maximum_msat: OptionalField::Present(250_000),
4285 fee_proportional_millionths: 0,
4286 excess_data: Vec::new()
4288 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4289 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4290 short_channel_id: 13,
4293 cltv_expiry_delta: 0,
4294 htlc_minimum_msat: 0,
4295 htlc_maximum_msat: OptionalField::Absent,
4297 fee_proportional_millionths: 0,
4298 excess_data: Vec::new()
4301 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4302 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4303 short_channel_id: 6,
4306 cltv_expiry_delta: 0,
4307 htlc_minimum_msat: 0,
4308 htlc_maximum_msat: OptionalField::Absent,
4309 fee_base_msat: 150_000,
4310 fee_proportional_millionths: 0,
4311 excess_data: Vec::new()
4313 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4314 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4315 short_channel_id: 11,
4318 cltv_expiry_delta: 0,
4319 htlc_minimum_msat: 0,
4320 htlc_maximum_msat: OptionalField::Absent,
4322 fee_proportional_millionths: 0,
4323 excess_data: Vec::new()
4327 // Attempt to route more than available results in a failure.
4328 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4329 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4330 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4331 } else { panic!(); }
4335 // Now, attempt to route 200 sats (exact amount we can route).
4336 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4337 assert_eq!(route.paths.len(), 2);
4339 let mut total_amount_paid_msat = 0;
4340 for path in &route.paths {
4341 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4342 total_amount_paid_msat += path.last().unwrap().fee_msat;
4344 assert_eq!(total_amount_paid_msat, 200_000);
4345 assert_eq!(route.get_total_fees(), 150_000);
4350 fn mpp_with_last_hops() {
4351 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4352 // via a single last-hop route hint, we'd fail to route if we first collected routes
4353 // totaling close but not quite enough to fund the full payment.
4355 // This was because we considered last-hop hints to have exactly the sought payment amount
4356 // instead of the amount we were trying to collect, needlessly limiting our path searching
4357 // at the very first hop.
4359 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4360 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4361 // to only have the remaining to-collect amount in available liquidity.
4363 // This bug appeared in production in some specific channel configurations.
4364 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4365 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4366 let scorer = test_utils::TestScorer::with_penalty(0);
4367 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4368 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4369 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4370 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4371 src_node_id: nodes[2],
4372 short_channel_id: 42,
4373 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4374 cltv_expiry_delta: 42,
4375 htlc_minimum_msat: None,
4376 htlc_maximum_msat: None,
4379 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4380 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4381 // would first use the no-fee route and then fail to find a path along the second route as
4382 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4383 // under 5% of our payment amount.
4384 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4385 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4386 short_channel_id: 1,
4389 cltv_expiry_delta: (5 << 4) | 5,
4390 htlc_minimum_msat: 0,
4391 htlc_maximum_msat: OptionalField::Present(99_000),
4392 fee_base_msat: u32::max_value(),
4393 fee_proportional_millionths: u32::max_value(),
4394 excess_data: Vec::new()
4396 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4397 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4398 short_channel_id: 2,
4401 cltv_expiry_delta: (5 << 4) | 3,
4402 htlc_minimum_msat: 0,
4403 htlc_maximum_msat: OptionalField::Present(99_000),
4404 fee_base_msat: u32::max_value(),
4405 fee_proportional_millionths: u32::max_value(),
4406 excess_data: Vec::new()
4408 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4409 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4410 short_channel_id: 4,
4413 cltv_expiry_delta: (4 << 4) | 1,
4414 htlc_minimum_msat: 0,
4415 htlc_maximum_msat: OptionalField::Absent,
4417 fee_proportional_millionths: 0,
4418 excess_data: Vec::new()
4420 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4421 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4422 short_channel_id: 13,
4424 flags: 0|2, // Channel disabled
4425 cltv_expiry_delta: (13 << 4) | 1,
4426 htlc_minimum_msat: 0,
4427 htlc_maximum_msat: OptionalField::Absent,
4429 fee_proportional_millionths: 2000000,
4430 excess_data: Vec::new()
4433 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4435 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4436 assert_eq!(route.paths.len(), 2);
4437 // Paths are somewhat randomly ordered, but:
4438 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4439 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4440 assert_eq!(route.paths[0][0].short_channel_id, 2);
4441 assert_eq!(route.paths[0][0].fee_msat, 1);
4442 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4443 assert_eq!(route.paths[1][0].short_channel_id, 1);
4444 assert_eq!(route.paths[1][0].fee_msat, 0);
4445 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4446 assert_eq!(route.get_total_fees(), 1);
4447 assert_eq!(route.get_total_amount(), 100_000);
4451 fn drop_lowest_channel_mpp_route_test() {
4452 // This test checks that low-capacity channel is dropped when after
4453 // path finding we realize that we found more capacity than we need.
4454 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4455 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4456 let scorer = test_utils::TestScorer::with_penalty(0);
4457 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4458 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4459 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4461 // We need a route consisting of 3 paths:
4462 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4464 // The first and the second paths should be sufficient, but the third should be
4465 // cheaper, so that we select it but drop later.
4467 // First, we set limits on these (previously unlimited) channels.
4468 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4470 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4471 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4472 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4473 short_channel_id: 1,
4476 cltv_expiry_delta: 0,
4477 htlc_minimum_msat: 0,
4478 htlc_maximum_msat: OptionalField::Present(100_000),
4480 fee_proportional_millionths: 0,
4481 excess_data: Vec::new()
4483 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4484 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4485 short_channel_id: 3,
4488 cltv_expiry_delta: 0,
4489 htlc_minimum_msat: 0,
4490 htlc_maximum_msat: OptionalField::Present(50_000),
4492 fee_proportional_millionths: 0,
4493 excess_data: Vec::new()
4496 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4497 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4498 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4499 short_channel_id: 12,
4502 cltv_expiry_delta: 0,
4503 htlc_minimum_msat: 0,
4504 htlc_maximum_msat: OptionalField::Present(60_000),
4506 fee_proportional_millionths: 0,
4507 excess_data: Vec::new()
4509 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4510 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4511 short_channel_id: 13,
4514 cltv_expiry_delta: 0,
4515 htlc_minimum_msat: 0,
4516 htlc_maximum_msat: OptionalField::Present(60_000),
4518 fee_proportional_millionths: 0,
4519 excess_data: Vec::new()
4522 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4523 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4524 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4525 short_channel_id: 2,
4528 cltv_expiry_delta: 0,
4529 htlc_minimum_msat: 0,
4530 htlc_maximum_msat: OptionalField::Present(20_000),
4532 fee_proportional_millionths: 0,
4533 excess_data: Vec::new()
4535 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4536 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4537 short_channel_id: 4,
4540 cltv_expiry_delta: 0,
4541 htlc_minimum_msat: 0,
4542 htlc_maximum_msat: OptionalField::Present(20_000),
4544 fee_proportional_millionths: 0,
4545 excess_data: Vec::new()
4549 // Attempt to route more than available results in a failure.
4550 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4551 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4552 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4553 } else { panic!(); }
4557 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4558 // Our algorithm should provide us with these 3 paths.
4559 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4560 assert_eq!(route.paths.len(), 3);
4561 let mut total_amount_paid_msat = 0;
4562 for path in &route.paths {
4563 assert_eq!(path.len(), 2);
4564 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4565 total_amount_paid_msat += path.last().unwrap().fee_msat;
4567 assert_eq!(total_amount_paid_msat, 125_000);
4571 // Attempt to route without the last small cheap channel
4572 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4573 assert_eq!(route.paths.len(), 2);
4574 let mut total_amount_paid_msat = 0;
4575 for path in &route.paths {
4576 assert_eq!(path.len(), 2);
4577 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4578 total_amount_paid_msat += path.last().unwrap().fee_msat;
4580 assert_eq!(total_amount_paid_msat, 90_000);
4585 fn min_criteria_consistency() {
4586 // Test that we don't use an inconsistent metric between updating and walking nodes during
4587 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4588 // was updated with a different criterion from the heap sorting, resulting in loops in
4589 // calculated paths. We test for that specific case here.
4591 // We construct a network that looks like this:
4593 // node2 -1(3)2- node3
4597 // node1 -1(5)2- node4 -1(1)2- node6
4603 // We create a loop on the side of our real path - our destination is node 6, with a
4604 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4605 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4606 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4607 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4608 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4609 // "previous hop" being set to node 3, creating a loop in the path.
4610 let secp_ctx = Secp256k1::new();
4611 let logger = Arc::new(test_utils::TestLogger::new());
4612 let network = Arc::new(NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash()));
4613 let net_graph_msg_handler = NetGraphMsgHandler::new(Arc::clone(&network), None, Arc::clone(&logger));
4614 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4615 let scorer = test_utils::TestScorer::with_penalty(0);
4616 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4617 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4618 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4620 add_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4621 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4622 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4623 short_channel_id: 6,
4626 cltv_expiry_delta: (6 << 4) | 0,
4627 htlc_minimum_msat: 0,
4628 htlc_maximum_msat: OptionalField::Absent,
4630 fee_proportional_millionths: 0,
4631 excess_data: Vec::new()
4633 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4635 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4636 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4637 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4638 short_channel_id: 5,
4641 cltv_expiry_delta: (5 << 4) | 0,
4642 htlc_minimum_msat: 0,
4643 htlc_maximum_msat: OptionalField::Absent,
4645 fee_proportional_millionths: 0,
4646 excess_data: Vec::new()
4648 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4650 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4651 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4652 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4653 short_channel_id: 4,
4656 cltv_expiry_delta: (4 << 4) | 0,
4657 htlc_minimum_msat: 0,
4658 htlc_maximum_msat: OptionalField::Absent,
4660 fee_proportional_millionths: 0,
4661 excess_data: Vec::new()
4663 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4665 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4666 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4667 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4668 short_channel_id: 3,
4671 cltv_expiry_delta: (3 << 4) | 0,
4672 htlc_minimum_msat: 0,
4673 htlc_maximum_msat: OptionalField::Absent,
4675 fee_proportional_millionths: 0,
4676 excess_data: Vec::new()
4678 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
4680 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
4681 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4682 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4683 short_channel_id: 2,
4686 cltv_expiry_delta: (2 << 4) | 0,
4687 htlc_minimum_msat: 0,
4688 htlc_maximum_msat: OptionalField::Absent,
4690 fee_proportional_millionths: 0,
4691 excess_data: Vec::new()
4694 add_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
4695 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4696 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4697 short_channel_id: 1,
4700 cltv_expiry_delta: (1 << 4) | 0,
4701 htlc_minimum_msat: 100,
4702 htlc_maximum_msat: OptionalField::Absent,
4704 fee_proportional_millionths: 0,
4705 excess_data: Vec::new()
4707 add_or_update_node(&net_graph_msg_handler, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
4710 // Now ensure the route flows simply over nodes 1 and 4 to 6.
4711 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4712 assert_eq!(route.paths.len(), 1);
4713 assert_eq!(route.paths[0].len(), 3);
4715 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
4716 assert_eq!(route.paths[0][0].short_channel_id, 6);
4717 assert_eq!(route.paths[0][0].fee_msat, 100);
4718 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
4719 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
4720 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
4722 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
4723 assert_eq!(route.paths[0][1].short_channel_id, 5);
4724 assert_eq!(route.paths[0][1].fee_msat, 0);
4725 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
4726 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
4727 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
4729 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
4730 assert_eq!(route.paths[0][2].short_channel_id, 1);
4731 assert_eq!(route.paths[0][2].fee_msat, 10_000);
4732 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
4733 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
4734 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
4740 fn exact_fee_liquidity_limit() {
4741 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
4742 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
4743 // we calculated fees on a higher value, resulting in us ignoring such paths.
4744 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4745 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
4746 let scorer = test_utils::TestScorer::with_penalty(0);
4747 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4748 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4749 let payment_params = PaymentParameters::from_node_id(nodes[2]);
4751 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
4753 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4754 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4755 short_channel_id: 2,
4758 cltv_expiry_delta: 0,
4759 htlc_minimum_msat: 0,
4760 htlc_maximum_msat: OptionalField::Present(85_000),
4762 fee_proportional_millionths: 0,
4763 excess_data: Vec::new()
4766 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4767 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4768 short_channel_id: 12,
4771 cltv_expiry_delta: (4 << 4) | 1,
4772 htlc_minimum_msat: 0,
4773 htlc_maximum_msat: OptionalField::Present(270_000),
4775 fee_proportional_millionths: 1000000,
4776 excess_data: Vec::new()
4780 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
4781 // 200% fee charged channel 13 in the 1-to-2 direction.
4782 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4783 assert_eq!(route.paths.len(), 1);
4784 assert_eq!(route.paths[0].len(), 2);
4786 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4787 assert_eq!(route.paths[0][0].short_channel_id, 12);
4788 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4789 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4790 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4791 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4793 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4794 assert_eq!(route.paths[0][1].short_channel_id, 13);
4795 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4796 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4797 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
4798 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4803 fn htlc_max_reduction_below_min() {
4804 // Test that if, while walking the graph, we reduce the value being sent to meet an
4805 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
4806 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
4807 // resulting in us thinking there is no possible path, even if other paths exist.
4808 let (secp_ctx, network_graph, net_graph_msg_handler, _, logger) = build_graph();
4809 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4810 let scorer = test_utils::TestScorer::with_penalty(0);
4811 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4812 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4813 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4815 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
4816 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
4817 // then try to send 90_000.
4818 update_channel(&net_graph_msg_handler, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4819 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4820 short_channel_id: 2,
4823 cltv_expiry_delta: 0,
4824 htlc_minimum_msat: 0,
4825 htlc_maximum_msat: OptionalField::Present(80_000),
4827 fee_proportional_millionths: 0,
4828 excess_data: Vec::new()
4830 update_channel(&net_graph_msg_handler, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4831 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4832 short_channel_id: 4,
4835 cltv_expiry_delta: (4 << 4) | 1,
4836 htlc_minimum_msat: 90_000,
4837 htlc_maximum_msat: OptionalField::Absent,
4839 fee_proportional_millionths: 0,
4840 excess_data: Vec::new()
4844 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
4845 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
4846 // expensive) channels 12-13 path.
4847 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4848 assert_eq!(route.paths.len(), 1);
4849 assert_eq!(route.paths[0].len(), 2);
4851 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
4852 assert_eq!(route.paths[0][0].short_channel_id, 12);
4853 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
4854 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
4855 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
4856 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
4858 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
4859 assert_eq!(route.paths[0][1].short_channel_id, 13);
4860 assert_eq!(route.paths[0][1].fee_msat, 90_000);
4861 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
4862 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
4863 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
4868 fn multiple_direct_first_hops() {
4869 // Previously we'd only ever considered one first hop path per counterparty.
4870 // However, as we don't restrict users to one channel per peer, we really need to support
4871 // looking at all first hop paths.
4872 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
4873 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
4874 // route over multiple channels with the same first hop.
4875 let secp_ctx = Secp256k1::new();
4876 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4877 let logger = Arc::new(test_utils::TestLogger::new());
4878 let network_graph = NetworkGraph::new(genesis_block(Network::Testnet).header.block_hash());
4879 let scorer = test_utils::TestScorer::with_penalty(0);
4880 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
4881 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4882 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4885 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4886 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
4887 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
4888 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4889 assert_eq!(route.paths.len(), 1);
4890 assert_eq!(route.paths[0].len(), 1);
4892 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4893 assert_eq!(route.paths[0][0].short_channel_id, 3);
4894 assert_eq!(route.paths[0][0].fee_msat, 100_000);
4897 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
4898 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
4899 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
4900 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4901 assert_eq!(route.paths.len(), 2);
4902 assert_eq!(route.paths[0].len(), 1);
4903 assert_eq!(route.paths[1].len(), 1);
4905 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
4906 assert_eq!(route.paths[0][0].short_channel_id, 3);
4907 assert_eq!(route.paths[0][0].fee_msat, 50_000);
4909 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
4910 assert_eq!(route.paths[1][0].short_channel_id, 2);
4911 assert_eq!(route.paths[1][0].fee_msat, 50_000);
4916 fn prefers_shorter_route_with_higher_fees() {
4917 let (secp_ctx, network_graph, _, _, logger) = build_graph();
4918 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4919 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
4921 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
4922 let scorer = test_utils::TestScorer::with_penalty(0);
4923 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4924 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4925 let route = get_route(
4926 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
4927 Arc::clone(&logger), &scorer, &random_seed_bytes
4929 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4931 assert_eq!(route.get_total_fees(), 100);
4932 assert_eq!(route.get_total_amount(), 100);
4933 assert_eq!(path, vec![2, 4, 6, 11, 8]);
4935 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
4936 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
4937 let scorer = test_utils::TestScorer::with_penalty(100);
4938 let route = get_route(
4939 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
4940 Arc::clone(&logger), &scorer, &random_seed_bytes
4942 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
4944 assert_eq!(route.get_total_fees(), 300);
4945 assert_eq!(route.get_total_amount(), 100);
4946 assert_eq!(path, vec![2, 4, 7, 10]);
4949 struct BadChannelScorer {
4950 short_channel_id: u64,
4954 impl Writeable for BadChannelScorer {
4955 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
4957 impl Score for BadChannelScorer {
4958 fn channel_penalty_msat(&self, short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, _target: &NodeId) -> u64 {
4959 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
4962 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
4963 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
4966 struct BadNodeScorer {
4971 impl Writeable for BadNodeScorer {
4972 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
4975 impl Score for BadNodeScorer {
4976 fn channel_penalty_msat(&self, _short_channel_id: u64, _send_amt: u64, _capacity_msat: u64, _source: &NodeId, target: &NodeId) -> u64 {
4977 if *target == self.node_id { u64::max_value() } else { 0 }
4980 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
4981 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
4985 fn avoids_routing_through_bad_channels_and_nodes() {
4986 let (secp_ctx, network, _, _, logger) = build_graph();
4987 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
4988 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
4989 let network_graph = network.read_only();
4991 // A path to nodes[6] exists when no penalties are applied to any channel.
4992 let scorer = test_utils::TestScorer::with_penalty(0);
4993 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4994 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4995 let route = get_route(
4996 &our_id, &payment_params, &network_graph, None, 100, 42,
4997 Arc::clone(&logger), &scorer, &random_seed_bytes
4999 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5001 assert_eq!(route.get_total_fees(), 100);
5002 assert_eq!(route.get_total_amount(), 100);
5003 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5005 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5006 let scorer = BadChannelScorer { short_channel_id: 6 };
5007 let route = get_route(
5008 &our_id, &payment_params, &network_graph, None, 100, 42,
5009 Arc::clone(&logger), &scorer, &random_seed_bytes
5011 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5013 assert_eq!(route.get_total_fees(), 300);
5014 assert_eq!(route.get_total_amount(), 100);
5015 assert_eq!(path, vec![2, 4, 7, 10]);
5017 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5018 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5020 &our_id, &payment_params, &network_graph, None, 100, 42,
5021 Arc::clone(&logger), &scorer, &random_seed_bytes
5023 Err(LightningError { err, .. } ) => {
5024 assert_eq!(err, "Failed to find a path to the given destination");
5026 Ok(_) => panic!("Expected error"),
5031 fn total_fees_single_path() {
5035 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5036 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5037 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5040 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5041 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5042 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5045 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5046 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5047 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5050 payment_params: None,
5053 assert_eq!(route.get_total_fees(), 250);
5054 assert_eq!(route.get_total_amount(), 225);
5058 fn total_fees_multi_path() {
5062 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5063 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5064 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5067 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5068 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5069 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5073 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5074 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5075 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5078 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5079 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5080 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5083 payment_params: None,
5086 assert_eq!(route.get_total_fees(), 200);
5087 assert_eq!(route.get_total_amount(), 300);
5091 fn total_empty_route_no_panic() {
5092 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5093 // would both panic if the route was completely empty. We test to ensure they return 0
5094 // here, even though its somewhat nonsensical as a route.
5095 let route = Route { paths: Vec::new(), payment_params: None };
5097 assert_eq!(route.get_total_fees(), 0);
5098 assert_eq!(route.get_total_amount(), 0);
5102 fn limits_total_cltv_delta() {
5103 let (secp_ctx, network, _, _, logger) = build_graph();
5104 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5105 let network_graph = network.read_only();
5107 let scorer = test_utils::TestScorer::with_penalty(0);
5109 // Make sure that generally there is at least one route available
5110 let feasible_max_total_cltv_delta = 1008;
5111 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5112 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5113 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5114 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5115 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5116 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5117 assert_ne!(path.len(), 0);
5119 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5120 let fail_max_total_cltv_delta = 23;
5121 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5122 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5123 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5125 Err(LightningError { err, .. } ) => {
5126 assert_eq!(err, "Failed to find a path to the given destination");
5128 Ok(_) => panic!("Expected error"),
5133 fn adds_and_limits_cltv_offset() {
5134 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5135 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5137 let scorer = test_utils::TestScorer::with_penalty(0);
5139 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5140 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5141 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5142 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5143 assert_eq!(route.paths.len(), 1);
5145 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5147 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5148 let mut route_default = route.clone();
5149 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5150 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5151 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5152 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5153 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5155 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5156 let mut route_limited = route.clone();
5157 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5158 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5159 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5160 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5161 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5165 fn adds_plausible_cltv_offset() {
5166 let (secp_ctx, network, _, _, logger) = build_graph();
5167 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5168 let network_graph = network.read_only();
5169 let network_nodes = network_graph.nodes();
5170 let network_channels = network_graph.channels();
5171 let scorer = test_utils::TestScorer::with_penalty(0);
5172 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5173 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5174 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5176 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5177 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5178 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5180 let mut path_plausibility = vec![];
5182 for p in route.paths {
5183 // 1. Select random observation point
5184 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5185 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5187 prng.process_in_place(&mut random_bytes);
5188 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5189 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5191 // 2. Calculate what CLTV expiry delta we would observe there
5192 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5194 // 3. Starting from the observation point, find candidate paths
5195 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5196 candidates.push_back((observation_point, vec![]));
5198 let mut found_plausible_candidate = false;
5200 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5201 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5202 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5203 found_plausible_candidate = true;
5204 break 'candidate_loop;
5208 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5209 for channel_id in &cur_node.channels {
5210 if let Some(channel_info) = network_channels.get(&channel_id) {
5211 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5212 if let Some(channel_update_info) = dir_info.direction() {
5213 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5214 if cur_path_cltv_deltas.iter().sum::<u32>()
5215 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5216 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5217 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5218 candidates.push_back((*next_id, new_path_cltv_deltas));
5227 path_plausibility.push(found_plausible_candidate);
5229 assert!(path_plausibility.iter().all(|x| *x));
5232 #[cfg(not(feature = "no-std"))]
5233 pub(super) fn random_init_seed() -> u64 {
5234 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5235 use core::hash::{BuildHasher, Hasher};
5236 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5237 println!("Using seed of {}", seed);
5240 #[cfg(not(feature = "no-std"))]
5241 use util::ser::Readable;
5244 #[cfg(not(feature = "no-std"))]
5245 fn generate_routes() {
5246 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5248 let mut d = match super::test_utils::get_route_file() {
5255 let graph = NetworkGraph::read(&mut d).unwrap();
5256 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5257 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5259 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5260 let mut seed = random_init_seed() as usize;
5261 let nodes = graph.read_only().nodes().clone();
5262 'load_endpoints: for _ in 0..10 {
5264 seed = seed.overflowing_mul(0xdeadbeef).0;
5265 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5266 seed = seed.overflowing_mul(0xdeadbeef).0;
5267 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5268 let payment_params = PaymentParameters::from_node_id(dst);
5269 let amt = seed as u64 % 200_000_000;
5270 let params = ProbabilisticScoringParameters::default();
5271 let scorer = ProbabilisticScorer::new(params, &graph);
5272 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5273 continue 'load_endpoints;
5280 #[cfg(not(feature = "no-std"))]
5281 fn generate_routes_mpp() {
5282 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5284 let mut d = match super::test_utils::get_route_file() {
5291 let graph = NetworkGraph::read(&mut d).unwrap();
5292 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5293 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5295 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5296 let mut seed = random_init_seed() as usize;
5297 let nodes = graph.read_only().nodes().clone();
5298 'load_endpoints: for _ in 0..10 {
5300 seed = seed.overflowing_mul(0xdeadbeef).0;
5301 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5302 seed = seed.overflowing_mul(0xdeadbeef).0;
5303 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5304 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5305 let amt = seed as u64 % 200_000_000;
5306 let params = ProbabilisticScoringParameters::default();
5307 let scorer = ProbabilisticScorer::new(params, &graph);
5308 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &test_utils::TestLogger::new(), &scorer, &random_seed_bytes).is_ok() {
5309 continue 'load_endpoints;
5316 #[cfg(all(test, not(feature = "no-std")))]
5317 pub(crate) mod test_utils {
5319 /// Tries to open a network graph file, or panics with a URL to fetch it.
5320 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5321 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5322 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5323 .or_else(|_| { // Fall back to guessing based on the binary location
5324 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5325 let mut path = std::env::current_exe().unwrap();
5326 path.pop(); // lightning-...
5328 path.pop(); // debug
5329 path.pop(); // target
5330 path.push("lightning");
5331 path.push("net_graph-2021-05-31.bin");
5332 eprintln!("{}", path.to_str().unwrap());
5335 .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");
5336 #[cfg(require_route_graph_test)]
5337 return Ok(res.unwrap());
5338 #[cfg(not(require_route_graph_test))]
5343 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5346 use bitcoin::hashes::Hash;
5347 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5348 use chain::transaction::OutPoint;
5349 use chain::keysinterface::{KeysManager,KeysInterface};
5350 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5351 use ln::features::{InitFeatures, InvoiceFeatures};
5352 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters, Scorer};
5353 use util::logger::{Logger, Record};
5357 struct DummyLogger {}
5358 impl Logger for DummyLogger {
5359 fn log(&self, _record: &Record) {}
5362 fn read_network_graph() -> NetworkGraph {
5363 let mut d = test_utils::get_route_file().unwrap();
5364 NetworkGraph::read(&mut d).unwrap()
5367 fn payer_pubkey() -> PublicKey {
5368 let secp_ctx = Secp256k1::new();
5369 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5373 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5375 channel_id: [0; 32],
5376 counterparty: ChannelCounterparty {
5377 features: InitFeatures::known(),
5379 unspendable_punishment_reserve: 0,
5380 forwarding_info: None,
5382 funding_txo: Some(OutPoint {
5383 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5385 short_channel_id: Some(1),
5386 inbound_scid_alias: None,
5387 channel_value_satoshis: 10_000_000,
5389 balance_msat: 10_000_000,
5390 outbound_capacity_msat: 10_000_000,
5391 inbound_capacity_msat: 0,
5392 unspendable_punishment_reserve: None,
5393 confirmations_required: None,
5394 force_close_spend_delay: None,
5396 is_funding_locked: true,
5403 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5404 let network_graph = read_network_graph();
5405 let scorer = FixedPenaltyScorer::with_penalty(0);
5406 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5410 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5411 let network_graph = read_network_graph();
5412 let scorer = FixedPenaltyScorer::with_penalty(0);
5413 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5417 fn generate_routes_with_default_scorer(bench: &mut Bencher) {
5418 let network_graph = read_network_graph();
5419 let scorer = Scorer::default();
5420 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5424 fn generate_mpp_routes_with_default_scorer(bench: &mut Bencher) {
5425 let network_graph = read_network_graph();
5426 let scorer = Scorer::default();
5427 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5431 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5432 let network_graph = read_network_graph();
5433 let params = ProbabilisticScoringParameters::default();
5434 let scorer = ProbabilisticScorer::new(params, &network_graph);
5435 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5439 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5440 let network_graph = read_network_graph();
5441 let params = ProbabilisticScoringParameters::default();
5442 let scorer = ProbabilisticScorer::new(params, &network_graph);
5443 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5446 fn generate_routes<S: Score>(
5447 bench: &mut Bencher, graph: &NetworkGraph, mut scorer: S, features: InvoiceFeatures
5449 let nodes = graph.read_only().nodes().clone();
5450 let payer = payer_pubkey();
5451 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5452 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5454 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5455 let mut routes = Vec::new();
5456 let mut route_endpoints = Vec::new();
5457 let mut seed: usize = 0xdeadbeef;
5458 'load_endpoints: for _ in 0..150 {
5461 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5463 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5464 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5465 let first_hop = first_hop(src);
5466 let amt = seed as u64 % 1_000_000;
5467 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5469 route_endpoints.push((first_hop, params, amt));
5470 continue 'load_endpoints;
5475 // ...and seed the scorer with success and failure data...
5476 for route in routes {
5477 let amount = route.get_total_amount();
5478 if amount < 250_000 {
5479 for path in route.paths {
5480 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5482 } else if amount > 750_000 {
5483 for path in route.paths {
5484 let short_channel_id = path[path.len() / 2].short_channel_id;
5485 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5490 // Because we've changed channel scores, its possible we'll take different routes to the
5491 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5492 // requires a too-high CLTV delta.
5493 route_endpoints.retain(|(first_hop, params, amt)| {
5494 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5496 route_endpoints.truncate(100);
5497 assert_eq!(route_endpoints.len(), 100);
5499 // ...then benchmark finding paths between the nodes we learned.
5502 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5503 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());