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 P2PGossipSync and use that as your RoutingMessageHandler and then
13 //! interrogate it to get routes for your own payments.
15 use bitcoin::secp256k1::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::gossip::{DirectedChannelInfoWithUpdate, EffectiveCapacity, ReadOnlyNetworkGraph, NodeId, RoutingFees};
21 use routing::scoring::{ChannelUsage, Score};
22 use util::ser::{Writeable, Readable, Writer};
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. Each entry represents a list of hops, NOT
69 /// INCLUDING our own, where the last hop is the destination. Thus, this must always be at
70 /// least length one. While the maximum length of any given path is variable, keeping the length
71 /// of any path less or equal to 19 should currently ensure it is viable.
72 pub paths: Vec<Vec<RouteHop>>,
73 /// The `payment_params` parameter passed to [`find_route`].
74 /// This is used by `ChannelManager` to track information which may be required for retries,
75 /// provided back to you via [`Event::PaymentPathFailed`].
77 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
78 pub payment_params: Option<PaymentParameters>,
81 pub(crate) trait RoutePath {
82 /// Gets the fees for a given path, excluding any excess paid to the recipient.
83 fn get_path_fees(&self) -> u64;
85 impl RoutePath for Vec<RouteHop> {
86 fn get_path_fees(&self) -> u64 {
87 // Do not count last hop of each path since that's the full value of the payment
88 self.split_last().map(|(_, path_prefix)| path_prefix).unwrap_or(&[])
89 .iter().map(|hop| &hop.fee_msat)
95 /// Returns the total amount of fees paid on this [`Route`].
97 /// This doesn't include any extra payment made to the recipient, which can happen in excess of
98 /// the amount passed to [`find_route`]'s `params.final_value_msat`.
99 pub fn get_total_fees(&self) -> u64 {
100 self.paths.iter().map(|path| path.get_path_fees()).sum()
103 /// Returns the total amount paid on this [`Route`], excluding the fees.
104 pub fn get_total_amount(&self) -> u64 {
105 return self.paths.iter()
106 .map(|path| path.split_last().map(|(hop, _)| hop.fee_msat).unwrap_or(0))
111 const SERIALIZATION_VERSION: u8 = 1;
112 const MIN_SERIALIZATION_VERSION: u8 = 1;
114 impl Writeable for Route {
115 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
116 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
117 (self.paths.len() as u64).write(writer)?;
118 for hops in self.paths.iter() {
119 (hops.len() as u8).write(writer)?;
120 for hop in hops.iter() {
124 write_tlv_fields!(writer, {
125 (1, self.payment_params, option),
131 impl Readable for Route {
132 fn read<R: io::Read>(reader: &mut R) -> Result<Route, DecodeError> {
133 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
134 let path_count: u64 = Readable::read(reader)?;
135 let mut paths = Vec::with_capacity(cmp::min(path_count, 128) as usize);
136 for _ in 0..path_count {
137 let hop_count: u8 = Readable::read(reader)?;
138 let mut hops = Vec::with_capacity(hop_count as usize);
139 for _ in 0..hop_count {
140 hops.push(Readable::read(reader)?);
144 let mut payment_params = None;
145 read_tlv_fields!(reader, {
146 (1, payment_params, option),
148 Ok(Route { paths, payment_params })
152 /// Parameters needed to find a [`Route`].
154 /// Passed to [`find_route`] and [`build_route_from_hops`], but also provided in
155 /// [`Event::PaymentPathFailed`] for retrying a failed payment path.
157 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
158 #[derive(Clone, Debug)]
159 pub struct RouteParameters {
160 /// The parameters of the failed payment path.
161 pub payment_params: PaymentParameters,
163 /// The amount in msats sent on the failed payment path.
164 pub final_value_msat: u64,
166 /// The CLTV on the final hop of the failed payment path.
167 pub final_cltv_expiry_delta: u32,
170 impl_writeable_tlv_based!(RouteParameters, {
171 (0, payment_params, required),
172 (2, final_value_msat, required),
173 (4, final_cltv_expiry_delta, required),
176 /// Maximum total CTLV difference we allow for a full payment path.
177 pub const DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA: u32 = 1008;
179 /// Maximum number of paths we allow an MPP payment to have.
180 // The default limit is currently set rather arbitrary - there aren't any real fundamental path-count
181 // limits, but for now more than 10 paths likely carries too much one-path failure.
182 pub const DEFAULT_MAX_MPP_PATH_COUNT: u8 = 10;
184 // The median hop CLTV expiry delta currently seen in the network.
185 const MEDIAN_HOP_CLTV_EXPIRY_DELTA: u32 = 40;
187 // During routing, we only consider paths shorter than our maximum length estimate.
188 // In the legacy onion format, the maximum number of hops used to be a fixed value of 20.
189 // However, in the TLV onion format, there is no fixed maximum length, but the `hop_payloads`
190 // field is always 1300 bytes. As the `tlv_payload` for each hop may vary in length, we have to
191 // estimate how many hops the route may have so that it actually fits the `hop_payloads` field.
193 // We estimate 3+32 (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) +
194 // 2+8 (short_channel_id) = 61 bytes for each intermediate hop and 3+32
195 // (payload length and HMAC) + 2+8 (amt_to_forward) + 2+4 (outgoing_cltv_value) + 2+32+8
196 // (payment_secret and total_msat) = 93 bytes for the final hop.
197 // Since the length of the potentially included `payment_metadata` is unknown to us, we round
198 // down from (1300-93) / 61 = 19.78... to arrive at a conservative estimate of 19.
199 const MAX_PATH_LENGTH_ESTIMATE: u8 = 19;
201 /// The recipient of a payment.
202 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
203 pub struct PaymentParameters {
204 /// The node id of the payee.
205 pub payee_pubkey: PublicKey,
207 /// Features supported by the payee.
209 /// May be set from the payee's invoice or via [`for_keysend`]. May be `None` if the invoice
210 /// does not contain any features.
212 /// [`for_keysend`]: Self::for_keysend
213 pub features: Option<InvoiceFeatures>,
215 /// Hints for routing to the payee, containing channels connecting the payee to public nodes.
216 pub route_hints: Vec<RouteHint>,
218 /// Expiration of a payment to the payee, in seconds relative to the UNIX epoch.
219 pub expiry_time: Option<u64>,
221 /// The maximum total CLTV delta we accept for the route.
222 /// Defaults to [`DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA`].
223 pub max_total_cltv_expiry_delta: u32,
225 /// The maximum number of paths that may be used by MPP payments.
226 /// Defaults to [`DEFAULT_MAX_MPP_PATH_COUNT`].
227 pub max_mpp_path_count: u8,
230 impl_writeable_tlv_based!(PaymentParameters, {
231 (0, payee_pubkey, required),
232 (1, max_total_cltv_expiry_delta, (default_value, DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA)),
233 (2, features, option),
234 (3, max_mpp_path_count, (default_value, DEFAULT_MAX_MPP_PATH_COUNT)),
235 (4, route_hints, vec_type),
236 (6, expiry_time, option),
239 impl PaymentParameters {
240 /// Creates a payee with the node id of the given `pubkey`.
241 pub fn from_node_id(payee_pubkey: PublicKey) -> Self {
247 max_total_cltv_expiry_delta: DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
248 max_mpp_path_count: DEFAULT_MAX_MPP_PATH_COUNT,
252 /// Creates a payee with the node id of the given `pubkey` to use for keysend payments.
253 pub fn for_keysend(payee_pubkey: PublicKey) -> Self {
254 Self::from_node_id(payee_pubkey).with_features(InvoiceFeatures::for_keysend())
257 /// Includes the payee's features.
259 /// (C-not exported) since bindings don't support move semantics
260 pub fn with_features(self, features: InvoiceFeatures) -> Self {
261 Self { features: Some(features), ..self }
264 /// Includes hints for routing to the payee.
266 /// (C-not exported) since bindings don't support move semantics
267 pub fn with_route_hints(self, route_hints: Vec<RouteHint>) -> Self {
268 Self { route_hints, ..self }
271 /// Includes a payment expiration in seconds relative to the UNIX epoch.
273 /// (C-not exported) since bindings don't support move semantics
274 pub fn with_expiry_time(self, expiry_time: u64) -> Self {
275 Self { expiry_time: Some(expiry_time), ..self }
278 /// Includes a limit for the total CLTV expiry delta which is considered during routing
280 /// (C-not exported) since bindings don't support move semantics
281 pub fn with_max_total_cltv_expiry_delta(self, max_total_cltv_expiry_delta: u32) -> Self {
282 Self { max_total_cltv_expiry_delta, ..self }
285 /// Includes a limit for the maximum number of payment paths that may be used by MPP.
287 /// (C-not exported) since bindings don't support move semantics
288 pub fn with_max_mpp_path_count(self, max_mpp_path_count: u8) -> Self {
289 Self { max_mpp_path_count, ..self }
293 /// A list of hops along a payment path terminating with a channel to the recipient.
294 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
295 pub struct RouteHint(pub Vec<RouteHintHop>);
297 impl Writeable for RouteHint {
298 fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
299 (self.0.len() as u64).write(writer)?;
300 for hop in self.0.iter() {
307 impl Readable for RouteHint {
308 fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
309 let hop_count: u64 = Readable::read(reader)?;
310 let mut hops = Vec::with_capacity(cmp::min(hop_count, 16) as usize);
311 for _ in 0..hop_count {
312 hops.push(Readable::read(reader)?);
318 /// A channel descriptor for a hop along a payment path.
319 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
320 pub struct RouteHintHop {
321 /// The node_id of the non-target end of the route
322 pub src_node_id: PublicKey,
323 /// The short_channel_id of this channel
324 pub short_channel_id: u64,
325 /// The fees which must be paid to use this channel
326 pub fees: RoutingFees,
327 /// The difference in CLTV values between this node and the next node.
328 pub cltv_expiry_delta: u16,
329 /// The minimum value, in msat, which must be relayed to the next hop.
330 pub htlc_minimum_msat: Option<u64>,
331 /// The maximum value in msat available for routing with a single HTLC.
332 pub htlc_maximum_msat: Option<u64>,
335 impl_writeable_tlv_based!(RouteHintHop, {
336 (0, src_node_id, required),
337 (1, htlc_minimum_msat, option),
338 (2, short_channel_id, required),
339 (3, htlc_maximum_msat, option),
341 (6, cltv_expiry_delta, required),
344 #[derive(Eq, PartialEq)]
345 struct RouteGraphNode {
347 lowest_fee_to_peer_through_node: u64,
348 lowest_fee_to_node: u64,
349 total_cltv_delta: u32,
350 // The maximum value a yet-to-be-constructed payment path might flow through this node.
351 // This value is upper-bounded by us by:
352 // - how much is needed for a path being constructed
353 // - how much value can channels following this node (up to the destination) can contribute,
354 // considering their capacity and fees
355 value_contribution_msat: u64,
356 /// The effective htlc_minimum_msat at this hop. If a later hop on the path had a higher HTLC
357 /// minimum, we use it, plus the fees required at each earlier hop to meet it.
358 path_htlc_minimum_msat: u64,
359 /// All penalties incurred from this hop on the way to the destination, as calculated using
361 path_penalty_msat: u64,
362 /// The number of hops walked up to this node.
363 path_length_to_node: u8,
366 impl cmp::Ord for RouteGraphNode {
367 fn cmp(&self, other: &RouteGraphNode) -> cmp::Ordering {
368 let other_score = cmp::max(other.lowest_fee_to_peer_through_node, other.path_htlc_minimum_msat)
369 .saturating_add(other.path_penalty_msat);
370 let self_score = cmp::max(self.lowest_fee_to_peer_through_node, self.path_htlc_minimum_msat)
371 .saturating_add(self.path_penalty_msat);
372 other_score.cmp(&self_score).then_with(|| other.node_id.cmp(&self.node_id))
376 impl cmp::PartialOrd for RouteGraphNode {
377 fn partial_cmp(&self, other: &RouteGraphNode) -> Option<cmp::Ordering> {
378 Some(self.cmp(other))
382 /// A wrapper around the various hop representations.
384 /// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
385 #[derive(Clone, Debug)]
386 enum CandidateRouteHop<'a> {
387 /// A hop from the payer, where the outbound liquidity is known.
389 details: &'a ChannelDetails,
391 /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
393 info: DirectedChannelInfoWithUpdate<'a>,
394 short_channel_id: u64,
396 /// A hop to the payee found in the payment invoice, though not necessarily a direct channel.
398 hint: &'a RouteHintHop,
402 impl<'a> CandidateRouteHop<'a> {
403 fn short_channel_id(&self) -> u64 {
405 CandidateRouteHop::FirstHop { details } => details.get_outbound_payment_scid().unwrap(),
406 CandidateRouteHop::PublicHop { short_channel_id, .. } => *short_channel_id,
407 CandidateRouteHop::PrivateHop { hint } => hint.short_channel_id,
411 // NOTE: This may alloc memory so avoid calling it in a hot code path.
412 fn features(&self) -> ChannelFeatures {
414 CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
415 CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
416 CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
420 fn cltv_expiry_delta(&self) -> u32 {
422 CandidateRouteHop::FirstHop { .. } => 0,
423 CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
424 CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
428 fn htlc_minimum_msat(&self) -> u64 {
430 CandidateRouteHop::FirstHop { .. } => 0,
431 CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
432 CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
436 fn htlc_maximum_msat(&self) -> u64 {
438 CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_limit_msat,
439 CandidateRouteHop::PublicHop { info, .. } => info.htlc_maximum_msat(),
440 CandidateRouteHop::PrivateHop { hint } => {
441 hint.htlc_maximum_msat.unwrap_or(u64::max_value())
446 fn fees(&self) -> RoutingFees {
448 CandidateRouteHop::FirstHop { .. } => RoutingFees {
449 base_msat: 0, proportional_millionths: 0,
451 CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
452 CandidateRouteHop::PrivateHop { hint } => hint.fees,
456 fn effective_capacity(&self) -> EffectiveCapacity {
458 CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
459 liquidity_msat: details.next_outbound_htlc_limit_msat,
461 CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
462 CandidateRouteHop::PrivateHop { .. } => EffectiveCapacity::Infinite,
467 /// It's useful to keep track of the hops associated with the fees required to use them,
468 /// so that we can choose cheaper paths (as per Dijkstra's algorithm).
469 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
470 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
472 struct PathBuildingHop<'a> {
473 // Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
474 // is a larger refactor and will require careful performance analysis.
476 candidate: CandidateRouteHop<'a>,
479 /// Minimal fees required to route to the source node of the current hop via any of its inbound channels.
480 src_lowest_inbound_fees: RoutingFees,
481 /// All the fees paid *after* this channel on the way to the destination
482 next_hops_fee_msat: u64,
483 /// Fee paid for the use of the current channel (see candidate.fees()).
484 /// The value will be actually deducted from the counterparty balance on the previous link.
485 hop_use_fee_msat: u64,
486 /// Used to compare channels when choosing the for routing.
487 /// Includes paying for the use of a hop and the following hops, as well as
488 /// an estimated cost of reaching this hop.
489 /// Might get stale when fees are recomputed. Primarily for internal use.
491 /// A mirror of the same field in RouteGraphNode. Note that this is only used during the graph
492 /// walk and may be invalid thereafter.
493 path_htlc_minimum_msat: u64,
494 /// All penalties incurred from this channel on the way to the destination, as calculated using
496 path_penalty_msat: u64,
497 /// If we've already processed a node as the best node, we shouldn't process it again. Normally
498 /// we'd just ignore it if we did as all channels would have a higher new fee, but because we
499 /// may decrease the amounts in use as we walk the graph, the actual calculated fee may
500 /// decrease as well. Thus, we have to explicitly track which nodes have been processed and
501 /// avoid processing them again.
503 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
504 // In tests, we apply further sanity checks on cases where we skip nodes we already processed
505 // to ensure it is specifically in cases where the fee has gone down because of a decrease in
506 // value_contribution_msat, which requires tracking it here. See comments below where it is
507 // used for more info.
508 value_contribution_msat: u64,
511 impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
512 fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
513 let mut debug_struct = f.debug_struct("PathBuildingHop");
515 .field("node_id", &self.node_id)
516 .field("short_channel_id", &self.candidate.short_channel_id())
517 .field("total_fee_msat", &self.total_fee_msat)
518 .field("next_hops_fee_msat", &self.next_hops_fee_msat)
519 .field("hop_use_fee_msat", &self.hop_use_fee_msat)
520 .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)))
521 .field("path_penalty_msat", &self.path_penalty_msat)
522 .field("path_htlc_minimum_msat", &self.path_htlc_minimum_msat)
523 .field("cltv_expiry_delta", &self.candidate.cltv_expiry_delta());
524 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
525 let debug_struct = debug_struct
526 .field("value_contribution_msat", &self.value_contribution_msat);
527 debug_struct.finish()
531 // Instantiated with a list of hops with correct data in them collected during path finding,
532 // an instance of this struct should be further modified only via given methods.
534 struct PaymentPath<'a> {
535 hops: Vec<(PathBuildingHop<'a>, NodeFeatures)>,
538 impl<'a> PaymentPath<'a> {
539 // TODO: Add a value_msat field to PaymentPath and use it instead of this function.
540 fn get_value_msat(&self) -> u64 {
541 self.hops.last().unwrap().0.fee_msat
544 fn get_path_penalty_msat(&self) -> u64 {
545 self.hops.first().map(|h| h.0.path_penalty_msat).unwrap_or(u64::max_value())
548 fn get_total_fee_paid_msat(&self) -> u64 {
549 if self.hops.len() < 1 {
553 // Can't use next_hops_fee_msat because it gets outdated.
554 for (i, (hop, _)) in self.hops.iter().enumerate() {
555 if i != self.hops.len() - 1 {
556 result += hop.fee_msat;
562 fn get_cost_msat(&self) -> u64 {
563 self.get_total_fee_paid_msat().saturating_add(self.get_path_penalty_msat())
566 // If the amount transferred by the path is updated, the fees should be adjusted. Any other way
567 // to change fees may result in an inconsistency.
569 // Sometimes we call this function right after constructing a path which is inconsistent in
570 // that it the value being transferred has decreased while we were doing path finding, leading
571 // to the fees being paid not lining up with the actual limits.
573 // Note that this function is not aware of the available_liquidity limit, and thus does not
574 // support increasing the value being transferred.
575 fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
576 assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
578 let mut total_fee_paid_msat = 0 as u64;
579 for i in (0..self.hops.len()).rev() {
580 let last_hop = i == self.hops.len() - 1;
582 // For non-last-hop, this value will represent the fees paid on the current hop. It
583 // will consist of the fees for the use of the next hop, and extra fees to match
584 // htlc_minimum_msat of the current channel. Last hop is handled separately.
585 let mut cur_hop_fees_msat = 0;
587 cur_hop_fees_msat = self.hops.get(i + 1).unwrap().0.hop_use_fee_msat;
590 let mut cur_hop = &mut self.hops.get_mut(i).unwrap().0;
591 cur_hop.next_hops_fee_msat = total_fee_paid_msat;
592 // Overpay in fees if we can't save these funds due to htlc_minimum_msat.
593 // We try to account for htlc_minimum_msat in scoring (add_entry!), so that nodes don't
594 // set it too high just to maliciously take more fees by exploiting this
595 // match htlc_minimum_msat logic.
596 let mut cur_hop_transferred_amount_msat = total_fee_paid_msat + value_msat;
597 if let Some(extra_fees_msat) = cur_hop.candidate.htlc_minimum_msat().checked_sub(cur_hop_transferred_amount_msat) {
598 // Note that there is a risk that *previous hops* (those closer to us, as we go
599 // payee->our_node here) would exceed their htlc_maximum_msat or available balance.
601 // This might make us end up with a broken route, although this should be super-rare
602 // in practice, both because of how healthy channels look like, and how we pick
603 // channels in add_entry.
604 // Also, this can't be exploited more heavily than *announce a free path and fail
606 cur_hop_transferred_amount_msat += extra_fees_msat;
607 total_fee_paid_msat += extra_fees_msat;
608 cur_hop_fees_msat += extra_fees_msat;
612 // Final hop is a special case: it usually has just value_msat (by design), but also
613 // it still could overpay for the htlc_minimum_msat.
614 cur_hop.fee_msat = cur_hop_transferred_amount_msat;
616 // Propagate updated fees for the use of the channels to one hop back, where they
617 // will be actually paid (fee_msat). The last hop is handled above separately.
618 cur_hop.fee_msat = cur_hop_fees_msat;
621 // Fee for the use of the current hop which will be deducted on the previous hop.
622 // Irrelevant for the first hop, as it doesn't have the previous hop, and the use of
623 // this channel is free for us.
625 if let Some(new_fee) = compute_fees(cur_hop_transferred_amount_msat, cur_hop.candidate.fees()) {
626 cur_hop.hop_use_fee_msat = new_fee;
627 total_fee_paid_msat += new_fee;
629 // It should not be possible because this function is called only to reduce the
630 // value. In that case, compute_fee was already called with the same fees for
631 // larger amount and there was no overflow.
639 fn compute_fees(amount_msat: u64, channel_fees: RoutingFees) -> Option<u64> {
640 let proportional_fee_millions =
641 amount_msat.checked_mul(channel_fees.proportional_millionths as u64);
642 if let Some(new_fee) = proportional_fee_millions.and_then(|part| {
643 (channel_fees.base_msat as u64).checked_add(part / 1_000_000) }) {
647 // This function may be (indirectly) called without any verification,
648 // with channel_fees provided by a caller. We should handle it gracefully.
653 /// The default `features` we assume for a node in a route, when no `features` are known about that
656 /// Default features are:
657 /// * variable_length_onion_optional
658 fn default_node_features() -> NodeFeatures {
659 let mut features = NodeFeatures::empty();
660 features.set_variable_length_onion_optional();
664 /// Finds a route from us (payer) to the given target node (payee).
666 /// If the payee provided features in their invoice, they should be provided via `params.payee`.
667 /// Without this, MPP will only be used if the payee's features are available in the network graph.
669 /// Private routing paths between a public node and the target may be included in `params.payee`.
671 /// If some channels aren't announced, it may be useful to fill in `first_hops` with the results
672 /// from [`ChannelManager::list_usable_channels`]. If it is filled in, the view of these channels
673 /// from `network_graph` will be ignored, and only those in `first_hops` will be used.
675 /// The fees on channels from us to the next hop are ignored as they are assumed to all be equal.
676 /// However, the enabled/disabled bit on such channels as well as the `htlc_minimum_msat` /
677 /// `htlc_maximum_msat` *are* checked as they may change based on the receiving node.
681 /// May be used to re-compute a [`Route`] when handling a [`Event::PaymentPathFailed`]. Any
682 /// adjustments to the [`NetworkGraph`] and channel scores should be made prior to calling this
687 /// Panics if first_hops contains channels without short_channel_ids;
688 /// [`ChannelManager::list_usable_channels`] will never include such channels.
690 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
691 /// [`Event::PaymentPathFailed`]: crate::util::events::Event::PaymentPathFailed
692 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
693 pub fn find_route<L: Deref, S: Score>(
694 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
695 network_graph: &ReadOnlyNetworkGraph, first_hops: Option<&[&ChannelDetails]>, logger: L,
696 scorer: &S, random_seed_bytes: &[u8; 32]
697 ) -> Result<Route, LightningError>
698 where L::Target: Logger {
699 let mut route = get_route(our_node_pubkey, &route_params.payment_params, network_graph, first_hops,
700 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, scorer,
702 add_random_cltv_offset(&mut route, &route_params.payment_params, network_graph, random_seed_bytes);
706 pub(crate) fn get_route<L: Deref, S: Score>(
707 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
708 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
709 logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
710 ) -> Result<Route, LightningError>
711 where L::Target: Logger {
712 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
713 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
715 if payee_node_id == our_node_id {
716 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
719 if final_value_msat > MAX_VALUE_MSAT {
720 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
723 if final_value_msat == 0 {
724 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
727 for route in payment_params.route_hints.iter() {
728 for hop in &route.0 {
729 if hop.src_node_id == payment_params.payee_pubkey {
730 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
734 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
735 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});
738 // The general routing idea is the following:
739 // 1. Fill first/last hops communicated by the caller.
740 // 2. Attempt to construct a path from payer to payee for transferring
741 // any ~sufficient (described later) value.
742 // If succeed, remember which channels were used and how much liquidity they have available,
743 // so that future paths don't rely on the same liquidity.
744 // 3. Proceed to the next step if:
745 // - we hit the recommended target value;
746 // - OR if we could not construct a new path. Any next attempt will fail too.
747 // Otherwise, repeat step 2.
748 // 4. See if we managed to collect paths which aggregately are able to transfer target value
749 // (not recommended value).
750 // 5. If yes, proceed. If not, fail routing.
751 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
752 // 7. Of all the found paths, select only those with the lowest total fee.
753 // 8. The last path in every selected route is likely to be more than we need.
754 // Reduce its value-to-transfer and recompute fees.
755 // 9. Choose the best route by the lowest total fee.
757 // As for the actual search algorithm,
758 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
759 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
761 // We are not a faithful Dijkstra's implementation because we can change values which impact
762 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
763 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
764 // the value we are currently attempting to send over a path, we simply reduce the value being
765 // sent along the path for any hops after that channel. This may imply that later fees (which
766 // we've already tabulated) are lower because a smaller value is passing through the channels
767 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
768 // channels which were selected earlier (and which may still be used for other paths without a
769 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
772 // One potentially problematic case for this algorithm would be if there are many
773 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
774 // graph walking), we may never find a path which is not liquidity-limited and has lower
775 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
776 // Because we only consider paths with at least 5% of the total value being sent, the damage
777 // from such a case should be limited, however this could be further reduced in the future by
778 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
779 // limits for the purposes of fee calculation.
781 // Alternatively, we could store more detailed path information in the heap (targets, below)
782 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
783 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
784 // and practically (as we would need to store dynamically-allocated path information in heap
785 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
786 // results of such an algorithm would likely be biased towards lower-value paths.
788 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
789 // outside of our current search value, running a path search more times to gather candidate
790 // paths at different values. While this may be acceptable, further path searches may increase
791 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
792 // graph for candidate paths, calculating the maximum value which can realistically be sent at
793 // the same time, remaining generic across different payment values.
795 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
796 // to use as the A* heuristic beyond just the cost to get one node further than the current
799 let network_channels = network_graph.channels();
800 let network_nodes = network_graph.nodes();
802 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
803 // it. If the payee supports it they're supposed to include it in the invoice, so that should
805 let allow_mpp = if let Some(features) = &payment_params.features {
806 features.supports_basic_mpp()
807 } else if let Some(node) = network_nodes.get(&payee_node_id) {
808 if let Some(node_info) = node.announcement_info.as_ref() {
809 node_info.features.supports_basic_mpp()
813 if allow_mpp && payment_params.max_mpp_path_count == 0 {
814 return Err(LightningError{err: "Can't find an MPP route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
817 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
818 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
819 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
822 // Prepare the data we'll use for payee-to-payer search by
823 // inserting first hops suggested by the caller as targets.
824 // Our search will then attempt to reach them while traversing from the payee node.
825 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
826 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
827 if let Some(hops) = first_hops {
829 if chan.get_outbound_payment_scid().is_none() {
830 panic!("first_hops should be filled in with usable channels, not pending ones");
832 if chan.counterparty.node_id == *our_node_pubkey {
833 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
836 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
837 .or_insert(Vec::new())
840 if first_hop_targets.is_empty() {
841 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
845 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
846 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
847 // adding duplicate entries when we find a better path to a given node.
848 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
850 // Map from node_id to information about the best current path to that node, including feerate
852 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
854 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
855 // indicating that we may wish to try again with a higher value, potentially paying to meet an
856 // htlc_minimum with extra fees while still finding a cheaper path.
857 let mut hit_minimum_limit;
859 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
860 // We start with a path_value of the exact amount we want, and if that generates a route we may
861 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
862 // amount we want in total across paths, selecting the best subset at the end.
863 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
864 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
865 let mut path_value_msat = final_value_msat;
867 // Routing Fragmentation Mitigation heuristic:
869 // Routing fragmentation across many payment paths increases the overall routing
870 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
871 // Taking too many smaller paths also increases the chance of payment failure.
872 // Thus to avoid this effect, we require from our collected links to provide
873 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
874 // This requirement is currently set to be 1/max_mpp_path_count of the payment
875 // value to ensure we only ever return routes that do not violate this limit.
876 let minimal_value_contribution_msat: u64 = if allow_mpp {
877 (final_value_msat + (payment_params.max_mpp_path_count as u64 - 1)) / payment_params.max_mpp_path_count as u64
882 // Keep track of how much liquidity has been used in selected channels. Used to determine
883 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
884 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
885 // liquidity used in one direction will not offset any used in the opposite direction.
886 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
887 HashMap::with_capacity(network_nodes.len());
889 // Keeping track of how much value we already collected across other paths. Helps to decide
890 // when we want to stop looking for new paths.
891 let mut already_collected_value_msat = 0;
893 for (_, channels) in first_hop_targets.iter_mut() {
894 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
897 // First, if channels are below `recommended_value_msat`, sort them in descending order,
898 // preferring larger channels to avoid splitting the payment into more MPP parts than is
901 // Second, because simply always sorting in descending order would always use our largest
902 // available outbound capacity, needlessly fragmenting our available channel capacities,
903 // sort channels above `recommended_value_msat` in ascending order, preferring channels
904 // which have enough, but not too much, capacity for the payment.
905 channels.sort_unstable_by(|chan_a, chan_b| {
906 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
907 // Sort in descending order
908 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
910 // Sort in ascending order
911 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
916 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
918 macro_rules! add_entry {
919 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
920 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
921 // since that value has to be transferred over this channel.
922 // Returns whether this channel caused an update to `targets`.
923 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
924 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
925 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
926 // We "return" whether we updated the path at the end, via this:
927 let mut did_add_update_path_to_src_node = false;
928 // Channels to self should not be used. This is more of belt-and-suspenders, because in
929 // practice these cases should be caught earlier:
930 // - for regular channels at channel announcement (TODO)
931 // - for first and last hops early in get_route
932 if $src_node_id != $dest_node_id {
933 let short_channel_id = $candidate.short_channel_id();
934 let htlc_maximum_msat = $candidate.htlc_maximum_msat();
936 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
937 // It may be misleading because we might later choose to reduce the value transferred
938 // over these channels, and the channel which was insufficient might become sufficient.
939 // Worst case: we drop a good channel here because it can't cover the high following
940 // fees caused by one expensive channel, but then this channel could have been used
941 // if the amount being transferred over this path is lower.
942 // We do this for now, but this is a subject for removal.
943 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
944 let used_liquidity_msat = used_channel_liquidities
945 .get(&(short_channel_id, $src_node_id < $dest_node_id))
946 .map_or(0, |used_liquidity_msat| {
947 available_value_contribution_msat = available_value_contribution_msat
948 .saturating_sub(*used_liquidity_msat);
952 // Verify the liquidity offered by this channel complies to the minimal contribution.
953 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
954 // Do not consider candidate hops that would exceed the maximum path length.
955 let path_length_to_node = $next_hops_path_length + 1;
956 let doesnt_exceed_max_path_length = path_length_to_node <= MAX_PATH_LENGTH_ESTIMATE;
958 // Do not consider candidates that exceed the maximum total cltv expiry limit.
959 // In order to already account for some of the privacy enhancing random CLTV
960 // expiry delta offset we add on top later, we subtract a rough estimate
961 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
962 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
963 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
964 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
965 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
966 .saturating_add($candidate.cltv_expiry_delta());
967 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
969 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
970 // Includes paying fees for the use of the following channels.
971 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
972 Some(result) => result,
973 // Can't overflow due to how the values were computed right above.
974 None => unreachable!(),
976 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
977 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
978 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
980 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
981 let may_overpay_to_meet_path_minimum_msat =
982 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
983 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
984 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
985 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
987 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
988 // bother considering this channel. If retrying with recommended_value_msat may
989 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
990 // around again with a higher amount.
991 if contributes_sufficient_value && doesnt_exceed_max_path_length &&
992 doesnt_exceed_cltv_delta_limit && may_overpay_to_meet_path_minimum_msat {
993 hit_minimum_limit = true;
994 } else if contributes_sufficient_value && doesnt_exceed_max_path_length &&
995 doesnt_exceed_cltv_delta_limit && over_path_minimum_msat {
996 // Note that low contribution here (limited by available_liquidity_msat)
997 // might violate htlc_minimum_msat on the hops which are next along the
998 // payment path (upstream to the payee). To avoid that, we recompute
999 // path fees knowing the final path contribution after constructing it.
1000 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
1001 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
1002 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
1003 .unwrap_or_else(|| u64::max_value());
1004 let hm_entry = dist.entry($src_node_id);
1005 let old_entry = hm_entry.or_insert_with(|| {
1006 // If there was previously no known way to access the source node
1007 // (recall it goes payee-to-payer) of short_channel_id, first add a
1008 // semi-dummy record just to compute the fees to reach the source node.
1009 // This will affect our decision on selecting short_channel_id
1010 // as a way to reach the $dest_node_id.
1011 let mut fee_base_msat = 0;
1012 let mut fee_proportional_millionths = 0;
1013 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
1014 fee_base_msat = fees.base_msat;
1015 fee_proportional_millionths = fees.proportional_millionths;
1018 node_id: $dest_node_id.clone(),
1019 candidate: $candidate.clone(),
1021 src_lowest_inbound_fees: RoutingFees {
1022 base_msat: fee_base_msat,
1023 proportional_millionths: fee_proportional_millionths,
1025 next_hops_fee_msat: u64::max_value(),
1026 hop_use_fee_msat: u64::max_value(),
1027 total_fee_msat: u64::max_value(),
1028 path_htlc_minimum_msat,
1029 path_penalty_msat: u64::max_value(),
1030 was_processed: false,
1031 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1032 value_contribution_msat,
1036 #[allow(unused_mut)] // We only use the mut in cfg(test)
1037 let mut should_process = !old_entry.was_processed;
1038 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1040 // In test/fuzzing builds, we do extra checks to make sure the skipping
1041 // of already-seen nodes only happens in cases we expect (see below).
1042 if !should_process { should_process = true; }
1046 let mut hop_use_fee_msat = 0;
1047 let mut total_fee_msat = $next_hops_fee_msat;
1049 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1050 // will have the same effective-fee
1051 if $src_node_id != our_node_id {
1052 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
1053 // max_value means we'll always fail
1054 // the old_entry.total_fee_msat > total_fee_msat check
1055 None => total_fee_msat = u64::max_value(),
1057 hop_use_fee_msat = fee_msat;
1058 total_fee_msat += hop_use_fee_msat;
1059 // When calculating the lowest inbound fees to a node, we
1060 // calculate fees here not based on the actual value we think
1061 // will flow over this channel, but on the minimum value that
1062 // we'll accept flowing over it. The minimum accepted value
1063 // is a constant through each path collection run, ensuring
1064 // consistent basis. Otherwise we may later find a
1065 // different path to the source node that is more expensive,
1066 // but which we consider to be cheaper because we are capacity
1067 // constrained and the relative fee becomes lower.
1068 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
1069 .map(|a| a.checked_add(total_fee_msat)) {
1074 total_fee_msat = u64::max_value();
1081 let channel_usage = ChannelUsage {
1082 amount_msat: amount_to_transfer_over_msat,
1083 inflight_htlc_msat: used_liquidity_msat,
1084 effective_capacity: $candidate.effective_capacity(),
1086 let channel_penalty_msat = scorer.channel_penalty_msat(
1087 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage
1089 let path_penalty_msat = $next_hops_path_penalty_msat
1090 .saturating_add(channel_penalty_msat);
1091 let new_graph_node = RouteGraphNode {
1092 node_id: $src_node_id,
1093 lowest_fee_to_peer_through_node: total_fee_msat,
1094 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1095 total_cltv_delta: hop_total_cltv_delta,
1096 value_contribution_msat: value_contribution_msat,
1097 path_htlc_minimum_msat,
1099 path_length_to_node,
1102 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1103 // if this way is cheaper than the already known
1104 // (considering the cost to "reach" this channel from the route destination,
1105 // the cost of using this channel,
1106 // and the cost of routing to the source node of this channel).
1107 // Also, consider that htlc_minimum_msat_difference, because we might end up
1108 // paying it. Consider the following exploit:
1109 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1110 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1111 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1112 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1114 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1115 // but it may require additional tracking - we don't want to double-count
1116 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1117 // can't use something that may decrease on future hops.
1118 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1119 .saturating_add(old_entry.path_penalty_msat);
1120 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1121 .saturating_add(path_penalty_msat);
1123 if !old_entry.was_processed && new_cost < old_cost {
1124 targets.push(new_graph_node);
1125 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1126 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1127 old_entry.total_fee_msat = total_fee_msat;
1128 old_entry.node_id = $dest_node_id.clone();
1129 old_entry.candidate = $candidate.clone();
1130 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1131 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1132 old_entry.path_penalty_msat = path_penalty_msat;
1133 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1135 old_entry.value_contribution_msat = value_contribution_msat;
1137 did_add_update_path_to_src_node = true;
1138 } else if old_entry.was_processed && new_cost < old_cost {
1139 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1141 // If we're skipping processing a node which was previously
1142 // processed even though we found another path to it with a
1143 // cheaper fee, check that it was because the second path we
1144 // found (which we are processing now) has a lower value
1145 // contribution due to an HTLC minimum limit.
1147 // e.g. take a graph with two paths from node 1 to node 2, one
1148 // through channel A, and one through channel B. Channel A and
1149 // B are both in the to-process heap, with their scores set by
1150 // a higher htlc_minimum than fee.
1151 // Channel A is processed first, and the channels onwards from
1152 // node 1 are added to the to-process heap. Thereafter, we pop
1153 // Channel B off of the heap, note that it has a much more
1154 // restrictive htlc_maximum_msat, and recalculate the fees for
1155 // all of node 1's channels using the new, reduced, amount.
1157 // This would be bogus - we'd be selecting a higher-fee path
1158 // with a lower htlc_maximum_msat instead of the one we'd
1159 // already decided to use.
1160 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1162 value_contribution_msat + path_penalty_msat <
1163 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1171 did_add_update_path_to_src_node
1175 let default_node_features = default_node_features();
1177 // Find ways (channels with destination) to reach a given node and store them
1178 // in the corresponding data structures (routing graph etc).
1179 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1180 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1181 // This data can later be helpful to optimize routing (pay lower fees).
1182 macro_rules! add_entries_to_cheapest_to_target_node {
1183 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1184 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1185 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1186 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1187 let was_processed = elem.was_processed;
1188 elem.was_processed = true;
1191 // Entries are added to dist in add_entry!() when there is a channel from a node.
1192 // Because there are no channels from payee, it will not have a dist entry at this point.
1193 // If we're processing any other node, it is always be the result of a channel from it.
1194 assert_eq!($node_id, payee_node_id);
1199 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1200 for details in first_channels {
1201 let candidate = CandidateRouteHop::FirstHop { details };
1202 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1203 $next_hops_value_contribution,
1204 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1205 $next_hops_cltv_delta, $next_hops_path_length);
1209 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1212 &default_node_features
1215 if !features.requires_unknown_bits() {
1216 for chan_id in $node.channels.iter() {
1217 let chan = network_channels.get(chan_id).unwrap();
1218 if !chan.features.requires_unknown_bits() {
1219 let (directed_channel, source) =
1220 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1221 if first_hops.is_none() || *source != our_node_id {
1222 if let Some(direction) = directed_channel.direction() {
1223 if direction.enabled {
1224 let candidate = CandidateRouteHop::PublicHop {
1225 info: directed_channel.with_update().unwrap(),
1226 short_channel_id: *chan_id,
1228 add_entry!(candidate, *source, $node_id,
1229 $fee_to_target_msat,
1230 $next_hops_value_contribution,
1231 $next_hops_path_htlc_minimum_msat,
1232 $next_hops_path_penalty_msat,
1233 $next_hops_cltv_delta, $next_hops_path_length);
1244 let mut payment_paths = Vec::<PaymentPath>::new();
1246 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1247 'paths_collection: loop {
1248 // For every new path, start from scratch, except for used_channel_liquidities, which
1249 // helps to avoid reusing previously selected paths in future iterations.
1252 hit_minimum_limit = false;
1254 // If first hop is a private channel and the only way to reach the payee, this is the only
1255 // place where it could be added.
1256 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1257 for details in first_channels {
1258 let candidate = CandidateRouteHop::FirstHop { details };
1259 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat,
1261 log_trace!(logger, "{} direct route to payee via SCID {}",
1262 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1266 // Add the payee as a target, so that the payee-to-payer
1267 // search algorithm knows what to start with.
1268 match network_nodes.get(&payee_node_id) {
1269 // The payee is not in our network graph, so nothing to add here.
1270 // There is still a chance of reaching them via last_hops though,
1271 // so don't yet fail the payment here.
1272 // If not, targets.pop() will not even let us enter the loop in step 2.
1275 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0, 0);
1280 // If a caller provided us with last hops, add them to routing targets. Since this happens
1281 // earlier than general path finding, they will be somewhat prioritized, although currently
1282 // it matters only if the fees are exactly the same.
1283 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1284 let first_hop_in_route = &(route.0)[0];
1285 let have_hop_src_in_graph =
1286 // Only add the hops in this route to our candidate set if either
1287 // we have a direct channel to the first hop or the first hop is
1288 // in the regular network graph.
1289 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1290 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1291 if have_hop_src_in_graph {
1292 // We start building the path from reverse, i.e., from payee
1293 // to the first RouteHintHop in the path.
1294 let hop_iter = route.0.iter().rev();
1295 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1296 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1297 let mut hop_used = true;
1298 let mut aggregate_next_hops_fee_msat: u64 = 0;
1299 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1300 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1301 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1302 let mut aggregate_next_hops_path_length: u8 = 0;
1304 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1305 let source = NodeId::from_pubkey(&hop.src_node_id);
1306 let target = NodeId::from_pubkey(&prev_hop_id);
1307 let candidate = network_channels
1308 .get(&hop.short_channel_id)
1309 .and_then(|channel| channel.as_directed_to(&target))
1310 .and_then(|(channel, _)| channel.with_update())
1311 .map(|info| CandidateRouteHop::PublicHop {
1313 short_channel_id: hop.short_channel_id,
1315 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1317 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
1318 path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
1319 aggregate_next_hops_path_penalty_msat,
1320 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
1321 // If this hop was not used then there is no use checking the preceding
1322 // hops in the RouteHint. We can break by just searching for a direct
1323 // channel between last checked hop and first_hop_targets.
1327 let used_liquidity_msat = used_channel_liquidities
1328 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1329 let channel_usage = ChannelUsage {
1330 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1331 inflight_htlc_msat: used_liquidity_msat,
1332 effective_capacity: candidate.effective_capacity(),
1334 let channel_penalty_msat = scorer.channel_penalty_msat(
1335 hop.short_channel_id, &source, &target, channel_usage
1337 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1338 .saturating_add(channel_penalty_msat);
1340 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1341 .saturating_add(hop.cltv_expiry_delta as u32);
1343 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1346 // Searching for a direct channel between last checked hop and first_hop_targets
1347 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1348 for details in first_channels {
1349 let candidate = CandidateRouteHop::FirstHop { details };
1350 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1351 aggregate_next_hops_fee_msat, path_value_msat,
1352 aggregate_next_hops_path_htlc_minimum_msat,
1353 aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
1354 aggregate_next_hops_path_length);
1362 // In the next values of the iterator, the aggregate fees already reflects
1363 // the sum of value sent from payer (final_value_msat) and routing fees
1364 // for the last node in the RouteHint. We need to just add the fees to
1365 // route through the current node so that the preceding node (next iteration)
1367 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1368 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1369 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1371 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1372 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1373 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1374 .checked_add(hop_htlc_minimum_msat_inc);
1375 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1377 if idx == route.0.len() - 1 {
1378 // The last hop in this iterator is the first hop in
1379 // overall RouteHint.
1380 // If this hop connects to a node with which we have a direct channel,
1381 // ignore the network graph and, if the last hop was added, add our
1382 // direct channel to the candidate set.
1384 // Note that we *must* check if the last hop was added as `add_entry`
1385 // always assumes that the third argument is a node to which we have a
1387 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1388 for details in first_channels {
1389 let candidate = CandidateRouteHop::FirstHop { details };
1390 add_entry!(candidate, our_node_id,
1391 NodeId::from_pubkey(&hop.src_node_id),
1392 aggregate_next_hops_fee_msat, path_value_msat,
1393 aggregate_next_hops_path_htlc_minimum_msat,
1394 aggregate_next_hops_path_penalty_msat,
1395 aggregate_next_hops_cltv_delta,
1396 aggregate_next_hops_path_length);
1404 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1406 // At this point, targets are filled with the data from first and
1407 // last hops communicated by the caller, and the payment receiver.
1408 let mut found_new_path = false;
1411 // If this loop terminates due the exhaustion of targets, two situations are possible:
1412 // - not enough outgoing liquidity:
1413 // 0 < already_collected_value_msat < final_value_msat
1414 // - enough outgoing liquidity:
1415 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1416 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1417 // paths_collection will be stopped because found_new_path==false.
1418 // This is not necessarily a routing failure.
1419 '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, path_length_to_node, .. }) = targets.pop() {
1421 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1422 // traversing the graph and arrange the path out of what we found.
1423 if node_id == our_node_id {
1424 let mut new_entry = dist.remove(&our_node_id).unwrap();
1425 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1428 let mut features_set = false;
1429 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1430 for details in first_channels {
1431 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1432 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1433 features_set = true;
1439 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1440 if let Some(node_info) = node.announcement_info.as_ref() {
1441 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1443 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1446 // We can fill in features for everything except hops which were
1447 // provided via the invoice we're paying. We could guess based on the
1448 // recipient's features but for now we simply avoid guessing at all.
1452 // Means we succesfully traversed from the payer to the payee, now
1453 // save this path for the payment route. Also, update the liquidity
1454 // remaining on the used hops, so that we take them into account
1455 // while looking for more paths.
1456 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1460 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1461 Some(payment_hop) => payment_hop,
1462 // We can't arrive at None because, if we ever add an entry to targets,
1463 // we also fill in the entry in dist (see add_entry!).
1464 None => unreachable!(),
1466 // We "propagate" the fees one hop backward (topologically) here,
1467 // so that fees paid for a HTLC forwarding on the current channel are
1468 // associated with the previous channel (where they will be subtracted).
1469 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1470 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1472 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1473 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1475 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1476 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1478 let mut payment_path = PaymentPath {hops: ordered_hops};
1480 // We could have possibly constructed a slightly inconsistent path: since we reduce
1481 // value being transferred along the way, we could have violated htlc_minimum_msat
1482 // on some channels we already passed (assuming dest->source direction). Here, we
1483 // recompute the fees again, so that if that's the case, we match the currently
1484 // underpaid htlc_minimum_msat with fees.
1485 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1487 // Since a path allows to transfer as much value as
1488 // the smallest channel it has ("bottleneck"), we should recompute
1489 // the fees so sender HTLC don't overpay fees when traversing
1490 // larger channels than the bottleneck. This may happen because
1491 // when we were selecting those channels we were not aware how much value
1492 // this path will transfer, and the relative fee for them
1493 // might have been computed considering a larger value.
1494 // Remember that we used these channels so that we don't rely
1495 // on the same liquidity in future paths.
1496 let mut prevented_redundant_path_selection = false;
1497 let prev_hop_iter = core::iter::once(&our_node_id)
1498 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1499 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1500 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1501 let used_liquidity_msat = used_channel_liquidities
1502 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1503 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
1504 .or_insert(spent_on_hop_msat);
1505 if *used_liquidity_msat == hop.candidate.htlc_maximum_msat() {
1506 // If this path used all of this channel's available liquidity, we know
1507 // this path will not be selected again in the next loop iteration.
1508 prevented_redundant_path_selection = true;
1510 debug_assert!(*used_liquidity_msat <= hop.candidate.htlc_maximum_msat());
1512 if !prevented_redundant_path_selection {
1513 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1514 // we'll probably end up picking the same path again on the next iteration.
1515 // Decrease the available liquidity of a hop in the middle of the path.
1516 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1517 let exhausted = u64::max_value();
1518 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1519 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
1520 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
1523 // Track the total amount all our collected paths allow to send so that we know
1524 // when to stop looking for more paths
1525 already_collected_value_msat += value_contribution_msat;
1527 payment_paths.push(payment_path);
1528 found_new_path = true;
1529 break 'path_construction;
1532 // If we found a path back to the payee, we shouldn't try to process it again. This is
1533 // the equivalent of the `elem.was_processed` check in
1534 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1535 if node_id == payee_node_id { continue 'path_construction; }
1537 // Otherwise, since the current target node is not us,
1538 // keep "unrolling" the payment graph from payee to payer by
1539 // finding a way to reach the current target from the payer side.
1540 match network_nodes.get(&node_id) {
1543 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
1544 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
1545 total_cltv_delta, path_length_to_node);
1551 // If we don't support MPP, no use trying to gather more value ever.
1552 break 'paths_collection;
1556 // Stop either when the recommended value is reached or if no new path was found in this
1558 // In the latter case, making another path finding attempt won't help,
1559 // because we deterministically terminated the search due to low liquidity.
1560 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1561 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1562 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1563 break 'paths_collection;
1564 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1565 // Further, if this was our first walk of the graph, and we weren't limited by an
1566 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1567 // limited by an htlc_minimum_msat value, find another path with a higher value,
1568 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1569 // still keeping a lower total fee than this path.
1570 if !hit_minimum_limit {
1571 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1572 break 'paths_collection;
1574 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1575 path_value_msat = recommended_value_msat;
1580 if payment_paths.len() == 0 {
1581 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1584 if already_collected_value_msat < final_value_msat {
1585 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1588 // Sort by total fees and take the best paths.
1589 payment_paths.sort_unstable_by_key(|path| path.get_total_fee_paid_msat());
1590 if payment_paths.len() > 50 {
1591 payment_paths.truncate(50);
1594 // Draw multiple sufficient routes by randomly combining the selected paths.
1595 let mut drawn_routes = Vec::new();
1596 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 12]);
1597 let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
1599 let num_permutations = payment_paths.len();
1600 for _ in 0..num_permutations {
1601 let mut cur_route = Vec::<PaymentPath>::new();
1602 let mut aggregate_route_value_msat = 0;
1605 // Do a Fisher-Yates shuffle to create a random permutation of the payment paths
1606 for cur_index in (1..payment_paths.len()).rev() {
1607 prng.process_in_place(&mut random_index_bytes);
1608 let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
1609 payment_paths.swap(cur_index, random_index);
1613 for payment_path in &payment_paths {
1614 cur_route.push(payment_path.clone());
1615 aggregate_route_value_msat += payment_path.get_value_msat();
1616 if aggregate_route_value_msat > final_value_msat {
1617 // Last path likely overpaid. Substract it from the most expensive
1618 // (in terms of proportional fee) path in this route and recompute fees.
1619 // This might be not the most economically efficient way, but fewer paths
1620 // also makes routing more reliable.
1621 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1623 // First, we drop some expensive low-value paths entirely if possible, since fewer
1624 // paths is better: the payment is less likely to fail. In order to do so, we sort
1625 // by value and fall back to total fees paid, i.e., in case of equal values we
1626 // prefer lower cost paths.
1627 cur_route.sort_unstable_by(|a, b| {
1628 a.get_value_msat().cmp(&b.get_value_msat())
1629 // Reverse ordering for cost, so we drop higher-cost paths first
1630 .then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
1633 // We should make sure that at least 1 path left.
1634 let mut paths_left = cur_route.len();
1635 cur_route.retain(|path| {
1636 if paths_left == 1 {
1639 let mut keep = true;
1640 let path_value_msat = path.get_value_msat();
1641 if path_value_msat <= overpaid_value_msat {
1643 overpaid_value_msat -= path_value_msat;
1649 if overpaid_value_msat == 0 {
1653 assert!(cur_route.len() > 0);
1656 // Now, subtract the overpaid value from the most-expensive path.
1657 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1658 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1659 cur_route.sort_unstable_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1660 let expensive_payment_path = cur_route.first_mut().unwrap();
1662 // We already dropped all the small value paths above, meaning all the
1663 // remaining paths are larger than remaining overpaid_value_msat.
1664 // Thus, this can't be negative.
1665 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1666 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1670 drawn_routes.push(cur_route);
1674 // Select the best route by lowest total cost.
1675 drawn_routes.sort_unstable_by_key(|paths| paths.iter().map(|path| path.get_cost_msat()).sum::<u64>());
1676 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1677 for payment_path in drawn_routes.first().unwrap() {
1678 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1680 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)})?,
1681 node_features: node_features.clone(),
1682 short_channel_id: payment_hop.candidate.short_channel_id(),
1683 channel_features: payment_hop.candidate.features(),
1684 fee_msat: payment_hop.fee_msat,
1685 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1687 }).collect::<Vec<_>>();
1688 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1689 // applicable for the previous hop.
1690 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1691 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1693 selected_paths.push(path);
1695 // Make sure we would never create a route with more paths than we allow.
1696 debug_assert!(selected_paths.len() <= payment_params.max_mpp_path_count.into());
1698 if let Some(features) = &payment_params.features {
1699 for path in selected_paths.iter_mut() {
1700 if let Ok(route_hop) = path.last_mut().unwrap() {
1701 route_hop.node_features = features.to_context();
1707 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1708 payment_params: Some(payment_params.clone()),
1710 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1714 // When an adversarial intermediary node observes a payment, it may be able to infer its
1715 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1716 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1717 // payment path by adding a randomized 'shadow route' offset to the final hop.
1718 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
1719 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
1721 let network_channels = network_graph.channels();
1722 let network_nodes = network_graph.nodes();
1724 for path in route.paths.iter_mut() {
1725 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1727 // Remember the last three nodes of the random walk and avoid looping back on them.
1728 // Init with the last three nodes from the actual path, if possible.
1729 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.last().unwrap().pubkey),
1730 NodeId::from_pubkey(&path.get(path.len().saturating_sub(2)).unwrap().pubkey),
1731 NodeId::from_pubkey(&path.get(path.len().saturating_sub(3)).unwrap().pubkey)];
1733 // Choose the last publicly known node as the starting point for the random walk.
1734 let mut cur_hop: Option<NodeId> = None;
1735 let mut path_nonce = [0u8; 12];
1736 if let Some(starting_hop) = path.iter().rev()
1737 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1738 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
1739 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
1742 // Init PRNG with the path-dependant nonce, which is static for private paths.
1743 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1744 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1746 // Pick a random path length in [1 .. 3]
1747 prng.process_in_place(&mut random_path_bytes);
1748 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1750 for random_hop in 0..random_walk_length {
1751 // If we don't find a suitable offset in the public network graph, we default to
1752 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1753 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1755 if let Some(cur_node_id) = cur_hop {
1756 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1757 // Randomly choose the next unvisited hop.
1758 prng.process_in_place(&mut random_path_bytes);
1759 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
1760 .checked_rem(cur_node.channels.len())
1761 .and_then(|index| cur_node.channels.get(index))
1762 .and_then(|id| network_channels.get(id)) {
1763 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1764 if !nodes_to_avoid.iter().any(|x| x == next_id) {
1765 nodes_to_avoid[random_hop] = *next_id;
1766 dir_info.direction().map(|channel_update_info| {
1767 random_hop_offset = channel_update_info.cltv_expiry_delta.into();
1768 cur_hop = Some(*next_id);
1776 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1777 .checked_add(random_hop_offset)
1778 .unwrap_or(shadow_ctlv_expiry_delta_offset);
1781 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1782 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1783 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1785 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1786 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1787 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1788 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1789 max_path_offset = cmp::max(
1790 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1791 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1792 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1794 // Add 'shadow' CLTV offset to the final hop
1795 if let Some(last_hop) = path.last_mut() {
1796 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1797 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1802 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
1803 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
1805 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
1806 pub fn build_route_from_hops<L: Deref>(
1807 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
1808 network_graph: &ReadOnlyNetworkGraph, logger: L, random_seed_bytes: &[u8; 32]
1809 ) -> Result<Route, LightningError>
1810 where L::Target: Logger {
1811 let mut route = build_route_from_hops_internal(
1812 our_node_pubkey, hops, &route_params.payment_params, &network_graph,
1813 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, random_seed_bytes)?;
1814 add_random_cltv_offset(&mut route, &route_params.payment_params, &network_graph, random_seed_bytes);
1818 fn build_route_from_hops_internal<L: Deref>(
1819 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
1820 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
1821 logger: L, random_seed_bytes: &[u8; 32]
1822 ) -> Result<Route, LightningError> where L::Target: Logger {
1825 our_node_id: NodeId,
1826 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
1829 impl Score for HopScorer {
1830 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
1831 _usage: ChannelUsage) -> u64
1833 let mut cur_id = self.our_node_id;
1834 for i in 0..self.hop_ids.len() {
1835 if let Some(next_id) = self.hop_ids[i] {
1836 if cur_id == *source && next_id == *target {
1847 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
1849 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
1852 impl<'a> Writeable for HopScorer {
1854 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
1859 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
1860 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
1863 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
1864 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
1865 for i in 0..hops.len() {
1866 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
1869 let scorer = HopScorer { our_node_id, hop_ids };
1871 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
1872 final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
1877 use routing::gossip::{NetworkGraph, P2PGossipSync, NodeId};
1878 use routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
1879 PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
1880 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
1881 use routing::scoring::{ChannelUsage, Score};
1882 use chain::transaction::OutPoint;
1883 use chain::keysinterface::KeysInterface;
1884 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1885 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1886 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1887 use ln::channelmanager;
1888 use util::test_utils;
1889 use util::chacha20::ChaCha20;
1890 use util::ser::Writeable;
1892 use util::ser::Writer;
1894 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1895 use bitcoin::hashes::Hash;
1896 use bitcoin::network::constants::Network;
1897 use bitcoin::blockdata::constants::genesis_block;
1898 use bitcoin::blockdata::script::Builder;
1899 use bitcoin::blockdata::opcodes;
1900 use bitcoin::blockdata::transaction::TxOut;
1904 use bitcoin::secp256k1::{PublicKey,SecretKey};
1905 use bitcoin::secp256k1::{Secp256k1, All};
1908 use sync::{self, Arc};
1910 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1911 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1912 channelmanager::ChannelDetails {
1913 channel_id: [0; 32],
1914 counterparty: channelmanager::ChannelCounterparty {
1917 unspendable_punishment_reserve: 0,
1918 forwarding_info: None,
1919 outbound_htlc_minimum_msat: None,
1920 outbound_htlc_maximum_msat: None,
1922 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1925 outbound_scid_alias: None,
1926 inbound_scid_alias: None,
1927 channel_value_satoshis: 0,
1930 outbound_capacity_msat,
1931 next_outbound_htlc_limit_msat: outbound_capacity_msat,
1932 inbound_capacity_msat: 42,
1933 unspendable_punishment_reserve: None,
1934 confirmations_required: None,
1935 force_close_spend_delay: None,
1936 is_outbound: true, is_channel_ready: true,
1937 is_usable: true, is_public: true,
1938 inbound_htlc_minimum_msat: None,
1939 inbound_htlc_maximum_msat: None,
1943 // Using the same keys for LN and BTC ids
1945 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1946 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1948 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1949 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1951 let unsigned_announcement = UnsignedChannelAnnouncement {
1953 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1957 bitcoin_key_1: node_id_1,
1958 bitcoin_key_2: node_id_2,
1959 excess_data: Vec::new(),
1962 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1963 let valid_announcement = ChannelAnnouncement {
1964 node_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1965 node_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1966 bitcoin_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1967 bitcoin_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1968 contents: unsigned_announcement.clone(),
1970 match gossip_sync.handle_channel_announcement(&valid_announcement) {
1971 Ok(res) => assert!(res),
1977 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1978 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1980 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1981 let valid_channel_update = ChannelUpdate {
1982 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
1983 contents: update.clone()
1986 match gossip_sync.handle_channel_update(&valid_channel_update) {
1987 Ok(res) => assert!(res),
1992 fn add_or_update_node(
1993 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1994 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
1996 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
1997 let unsigned_announcement = UnsignedNodeAnnouncement {
2003 addresses: Vec::new(),
2004 excess_address_data: Vec::new(),
2005 excess_data: Vec::new(),
2007 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
2008 let valid_announcement = NodeAnnouncement {
2009 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
2010 contents: unsigned_announcement.clone()
2013 match gossip_sync.handle_node_announcement(&valid_announcement) {
2019 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
2020 let privkeys: Vec<SecretKey> = (2..22).map(|i| {
2021 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
2024 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
2026 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
2027 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
2029 (our_privkey, our_id, privkeys, pubkeys)
2032 fn id_to_feature_flags(id: u8) -> Vec<u8> {
2033 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
2034 // test for it later.
2035 let idx = (id - 1) * 2 + 1;
2037 vec![1 << (idx - 8*3), 0, 0, 0]
2038 } else if idx > 8*2 {
2039 vec![1 << (idx - 8*2), 0, 0]
2040 } else if idx > 8*1 {
2041 vec![1 << (idx - 8*1), 0]
2047 fn build_line_graph() -> (
2048 Secp256k1<All>, sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2049 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2050 sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>,
2052 let secp_ctx = Secp256k1::new();
2053 let logger = Arc::new(test_utils::TestLogger::new());
2054 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2055 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2056 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2057 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2059 // Build network from our_id to node 19:
2060 // our_id -1(1)2- node0 -1(2)2- node1 - ... - node19
2061 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2063 for (idx, (cur_privkey, next_privkey)) in core::iter::once(&our_privkey)
2064 .chain(privkeys.iter()).zip(privkeys.iter()).enumerate() {
2065 let cur_short_channel_id = (idx as u64) + 1;
2066 add_channel(&gossip_sync, &secp_ctx, &cur_privkey, &next_privkey,
2067 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), cur_short_channel_id);
2068 update_channel(&gossip_sync, &secp_ctx, &cur_privkey, UnsignedChannelUpdate {
2069 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2070 short_channel_id: cur_short_channel_id,
2071 timestamp: idx as u32,
2073 cltv_expiry_delta: 0,
2074 htlc_minimum_msat: 0,
2075 htlc_maximum_msat: OptionalField::Absent,
2077 fee_proportional_millionths: 0,
2078 excess_data: Vec::new()
2080 update_channel(&gossip_sync, &secp_ctx, &next_privkey, UnsignedChannelUpdate {
2081 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2082 short_channel_id: cur_short_channel_id,
2083 timestamp: (idx as u32)+1,
2085 cltv_expiry_delta: 0,
2086 htlc_minimum_msat: 0,
2087 htlc_maximum_msat: OptionalField::Absent,
2089 fee_proportional_millionths: 0,
2090 excess_data: Vec::new()
2092 add_or_update_node(&gossip_sync, &secp_ctx, next_privkey,
2093 NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2096 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2099 fn build_graph() -> (
2101 sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2102 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2103 sync::Arc<test_utils::TestChainSource>,
2104 sync::Arc<test_utils::TestLogger>,
2106 let secp_ctx = Secp256k1::new();
2107 let logger = Arc::new(test_utils::TestLogger::new());
2108 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2109 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2110 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2111 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2112 // Build network from our_id to node6:
2114 // -1(1)2- node0 -1(3)2-
2116 // our_id -1(12)2- node7 -1(13)2--- node2
2118 // -1(2)2- node1 -1(4)2-
2121 // chan1 1-to-2: disabled
2122 // chan1 2-to-1: enabled, 0 fee
2124 // chan2 1-to-2: enabled, ignored fee
2125 // chan2 2-to-1: enabled, 0 fee
2127 // chan3 1-to-2: enabled, 0 fee
2128 // chan3 2-to-1: enabled, 100 msat fee
2130 // chan4 1-to-2: enabled, 100% fee
2131 // chan4 2-to-1: enabled, 0 fee
2133 // chan12 1-to-2: enabled, ignored fee
2134 // chan12 2-to-1: enabled, 0 fee
2136 // chan13 1-to-2: enabled, 200% fee
2137 // chan13 2-to-1: enabled, 0 fee
2140 // -1(5)2- node3 -1(8)2--
2144 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
2146 // -1(7)2- node5 -1(10)2-
2148 // Channels 5, 8, 9 and 10 are private channels.
2150 // chan5 1-to-2: enabled, 100 msat fee
2151 // chan5 2-to-1: enabled, 0 fee
2153 // chan6 1-to-2: enabled, 0 fee
2154 // chan6 2-to-1: enabled, 0 fee
2156 // chan7 1-to-2: enabled, 100% fee
2157 // chan7 2-to-1: enabled, 0 fee
2159 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
2160 // chan8 2-to-1: enabled, 0 fee
2162 // chan9 1-to-2: enabled, 1001 msat fee
2163 // chan9 2-to-1: enabled, 0 fee
2165 // chan10 1-to-2: enabled, 0 fee
2166 // chan10 2-to-1: enabled, 0 fee
2168 // chan11 1-to-2: enabled, 0 fee
2169 // chan11 2-to-1: enabled, 0 fee
2171 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2173 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
2174 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2175 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2176 short_channel_id: 1,
2179 cltv_expiry_delta: 0,
2180 htlc_minimum_msat: 0,
2181 htlc_maximum_msat: OptionalField::Absent,
2183 fee_proportional_millionths: 0,
2184 excess_data: Vec::new()
2187 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2189 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
2190 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2191 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2192 short_channel_id: 2,
2195 cltv_expiry_delta: (5 << 4) | 3,
2196 htlc_minimum_msat: 0,
2197 htlc_maximum_msat: OptionalField::Absent,
2198 fee_base_msat: u32::max_value(),
2199 fee_proportional_millionths: u32::max_value(),
2200 excess_data: Vec::new()
2202 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2203 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2204 short_channel_id: 2,
2207 cltv_expiry_delta: 0,
2208 htlc_minimum_msat: 0,
2209 htlc_maximum_msat: OptionalField::Absent,
2211 fee_proportional_millionths: 0,
2212 excess_data: Vec::new()
2215 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
2217 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
2218 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2219 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2220 short_channel_id: 12,
2223 cltv_expiry_delta: (5 << 4) | 3,
2224 htlc_minimum_msat: 0,
2225 htlc_maximum_msat: OptionalField::Absent,
2226 fee_base_msat: u32::max_value(),
2227 fee_proportional_millionths: u32::max_value(),
2228 excess_data: Vec::new()
2230 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2231 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2232 short_channel_id: 12,
2235 cltv_expiry_delta: 0,
2236 htlc_minimum_msat: 0,
2237 htlc_maximum_msat: OptionalField::Absent,
2239 fee_proportional_millionths: 0,
2240 excess_data: Vec::new()
2243 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
2245 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
2246 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2247 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2248 short_channel_id: 3,
2251 cltv_expiry_delta: (3 << 4) | 1,
2252 htlc_minimum_msat: 0,
2253 htlc_maximum_msat: OptionalField::Absent,
2255 fee_proportional_millionths: 0,
2256 excess_data: Vec::new()
2258 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2259 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2260 short_channel_id: 3,
2263 cltv_expiry_delta: (3 << 4) | 2,
2264 htlc_minimum_msat: 0,
2265 htlc_maximum_msat: OptionalField::Absent,
2267 fee_proportional_millionths: 0,
2268 excess_data: Vec::new()
2271 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
2272 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2273 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2274 short_channel_id: 4,
2277 cltv_expiry_delta: (4 << 4) | 1,
2278 htlc_minimum_msat: 0,
2279 htlc_maximum_msat: OptionalField::Absent,
2281 fee_proportional_millionths: 1000000,
2282 excess_data: Vec::new()
2284 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2285 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2286 short_channel_id: 4,
2289 cltv_expiry_delta: (4 << 4) | 2,
2290 htlc_minimum_msat: 0,
2291 htlc_maximum_msat: OptionalField::Absent,
2293 fee_proportional_millionths: 0,
2294 excess_data: Vec::new()
2297 add_channel(&gossip_sync, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2298 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2299 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2300 short_channel_id: 13,
2303 cltv_expiry_delta: (13 << 4) | 1,
2304 htlc_minimum_msat: 0,
2305 htlc_maximum_msat: OptionalField::Absent,
2307 fee_proportional_millionths: 2000000,
2308 excess_data: Vec::new()
2310 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2311 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2312 short_channel_id: 13,
2315 cltv_expiry_delta: (13 << 4) | 2,
2316 htlc_minimum_msat: 0,
2317 htlc_maximum_msat: OptionalField::Absent,
2319 fee_proportional_millionths: 0,
2320 excess_data: Vec::new()
2323 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2325 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2326 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2327 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2328 short_channel_id: 6,
2331 cltv_expiry_delta: (6 << 4) | 1,
2332 htlc_minimum_msat: 0,
2333 htlc_maximum_msat: OptionalField::Absent,
2335 fee_proportional_millionths: 0,
2336 excess_data: Vec::new()
2338 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2339 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2340 short_channel_id: 6,
2343 cltv_expiry_delta: (6 << 4) | 2,
2344 htlc_minimum_msat: 0,
2345 htlc_maximum_msat: OptionalField::Absent,
2347 fee_proportional_millionths: 0,
2348 excess_data: Vec::new(),
2351 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2352 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2353 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2354 short_channel_id: 11,
2357 cltv_expiry_delta: (11 << 4) | 1,
2358 htlc_minimum_msat: 0,
2359 htlc_maximum_msat: OptionalField::Absent,
2361 fee_proportional_millionths: 0,
2362 excess_data: Vec::new()
2364 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2365 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2366 short_channel_id: 11,
2369 cltv_expiry_delta: (11 << 4) | 2,
2370 htlc_minimum_msat: 0,
2371 htlc_maximum_msat: OptionalField::Absent,
2373 fee_proportional_millionths: 0,
2374 excess_data: Vec::new()
2377 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2379 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2381 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2382 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2383 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2384 short_channel_id: 7,
2387 cltv_expiry_delta: (7 << 4) | 1,
2388 htlc_minimum_msat: 0,
2389 htlc_maximum_msat: OptionalField::Absent,
2391 fee_proportional_millionths: 1000000,
2392 excess_data: Vec::new()
2394 update_channel(&gossip_sync, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2395 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2396 short_channel_id: 7,
2399 cltv_expiry_delta: (7 << 4) | 2,
2400 htlc_minimum_msat: 0,
2401 htlc_maximum_msat: OptionalField::Absent,
2403 fee_proportional_millionths: 0,
2404 excess_data: Vec::new()
2407 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2409 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2413 fn simple_route_test() {
2414 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2415 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2416 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2417 let scorer = test_utils::TestScorer::with_penalty(0);
2418 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2419 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2421 // Simple route to 2 via 1
2423 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) {
2424 assert_eq!(err, "Cannot send a payment of 0 msat");
2425 } else { panic!(); }
2427 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2428 assert_eq!(route.paths[0].len(), 2);
2430 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2431 assert_eq!(route.paths[0][0].short_channel_id, 2);
2432 assert_eq!(route.paths[0][0].fee_msat, 100);
2433 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2434 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2435 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2437 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2438 assert_eq!(route.paths[0][1].short_channel_id, 4);
2439 assert_eq!(route.paths[0][1].fee_msat, 100);
2440 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2441 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2442 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2446 fn invalid_first_hop_test() {
2447 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2448 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2449 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2450 let scorer = test_utils::TestScorer::with_penalty(0);
2451 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2452 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2454 // Simple route to 2 via 1
2456 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2458 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2459 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) {
2460 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2461 } else { panic!(); }
2463 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2464 assert_eq!(route.paths[0].len(), 2);
2468 fn htlc_minimum_test() {
2469 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2470 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2471 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2472 let scorer = test_utils::TestScorer::with_penalty(0);
2473 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2474 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2476 // Simple route to 2 via 1
2478 // Disable other paths
2479 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2480 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2481 short_channel_id: 12,
2483 flags: 2, // to disable
2484 cltv_expiry_delta: 0,
2485 htlc_minimum_msat: 0,
2486 htlc_maximum_msat: OptionalField::Absent,
2488 fee_proportional_millionths: 0,
2489 excess_data: Vec::new()
2491 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2492 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2493 short_channel_id: 3,
2495 flags: 2, // to disable
2496 cltv_expiry_delta: 0,
2497 htlc_minimum_msat: 0,
2498 htlc_maximum_msat: OptionalField::Absent,
2500 fee_proportional_millionths: 0,
2501 excess_data: Vec::new()
2503 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2504 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2505 short_channel_id: 13,
2507 flags: 2, // to disable
2508 cltv_expiry_delta: 0,
2509 htlc_minimum_msat: 0,
2510 htlc_maximum_msat: OptionalField::Absent,
2512 fee_proportional_millionths: 0,
2513 excess_data: Vec::new()
2515 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2516 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2517 short_channel_id: 6,
2519 flags: 2, // to disable
2520 cltv_expiry_delta: 0,
2521 htlc_minimum_msat: 0,
2522 htlc_maximum_msat: OptionalField::Absent,
2524 fee_proportional_millionths: 0,
2525 excess_data: Vec::new()
2527 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2528 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2529 short_channel_id: 7,
2531 flags: 2, // to disable
2532 cltv_expiry_delta: 0,
2533 htlc_minimum_msat: 0,
2534 htlc_maximum_msat: OptionalField::Absent,
2536 fee_proportional_millionths: 0,
2537 excess_data: Vec::new()
2540 // Check against amount_to_transfer_over_msat.
2541 // Set minimal HTLC of 200_000_000 msat.
2542 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2543 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2544 short_channel_id: 2,
2547 cltv_expiry_delta: 0,
2548 htlc_minimum_msat: 200_000_000,
2549 htlc_maximum_msat: OptionalField::Absent,
2551 fee_proportional_millionths: 0,
2552 excess_data: Vec::new()
2555 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2557 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2558 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2559 short_channel_id: 4,
2562 cltv_expiry_delta: 0,
2563 htlc_minimum_msat: 0,
2564 htlc_maximum_msat: OptionalField::Present(199_999_999),
2566 fee_proportional_millionths: 0,
2567 excess_data: Vec::new()
2570 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2571 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) {
2572 assert_eq!(err, "Failed to find a path to the given destination");
2573 } else { panic!(); }
2575 // Lift the restriction on the first hop.
2576 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2577 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2578 short_channel_id: 2,
2581 cltv_expiry_delta: 0,
2582 htlc_minimum_msat: 0,
2583 htlc_maximum_msat: OptionalField::Absent,
2585 fee_proportional_millionths: 0,
2586 excess_data: Vec::new()
2589 // A payment above the minimum should pass
2590 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();
2591 assert_eq!(route.paths[0].len(), 2);
2595 fn htlc_minimum_overpay_test() {
2596 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2597 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2598 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2599 let scorer = test_utils::TestScorer::with_penalty(0);
2600 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2601 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2603 // A route to node#2 via two paths.
2604 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2605 // Thus, they can't send 60 without overpaying.
2606 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2607 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2608 short_channel_id: 2,
2611 cltv_expiry_delta: 0,
2612 htlc_minimum_msat: 35_000,
2613 htlc_maximum_msat: OptionalField::Present(40_000),
2615 fee_proportional_millionths: 0,
2616 excess_data: Vec::new()
2618 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2619 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2620 short_channel_id: 12,
2623 cltv_expiry_delta: 0,
2624 htlc_minimum_msat: 35_000,
2625 htlc_maximum_msat: OptionalField::Present(40_000),
2627 fee_proportional_millionths: 0,
2628 excess_data: Vec::new()
2632 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2633 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2634 short_channel_id: 13,
2637 cltv_expiry_delta: 0,
2638 htlc_minimum_msat: 0,
2639 htlc_maximum_msat: OptionalField::Absent,
2641 fee_proportional_millionths: 0,
2642 excess_data: Vec::new()
2644 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2645 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2646 short_channel_id: 4,
2649 cltv_expiry_delta: 0,
2650 htlc_minimum_msat: 0,
2651 htlc_maximum_msat: OptionalField::Absent,
2653 fee_proportional_millionths: 0,
2654 excess_data: Vec::new()
2657 // Disable other paths
2658 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2659 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2660 short_channel_id: 1,
2662 flags: 2, // to disable
2663 cltv_expiry_delta: 0,
2664 htlc_minimum_msat: 0,
2665 htlc_maximum_msat: OptionalField::Absent,
2667 fee_proportional_millionths: 0,
2668 excess_data: Vec::new()
2671 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2672 // Overpay fees to hit htlc_minimum_msat.
2673 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2674 // TODO: this could be better balanced to overpay 10k and not 15k.
2675 assert_eq!(overpaid_fees, 15_000);
2677 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2678 // while taking even more fee to match htlc_minimum_msat.
2679 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2680 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2681 short_channel_id: 12,
2684 cltv_expiry_delta: 0,
2685 htlc_minimum_msat: 65_000,
2686 htlc_maximum_msat: OptionalField::Present(80_000),
2688 fee_proportional_millionths: 0,
2689 excess_data: Vec::new()
2691 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2692 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2693 short_channel_id: 2,
2696 cltv_expiry_delta: 0,
2697 htlc_minimum_msat: 0,
2698 htlc_maximum_msat: OptionalField::Absent,
2700 fee_proportional_millionths: 0,
2701 excess_data: Vec::new()
2703 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2704 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2705 short_channel_id: 4,
2708 cltv_expiry_delta: 0,
2709 htlc_minimum_msat: 0,
2710 htlc_maximum_msat: OptionalField::Absent,
2712 fee_proportional_millionths: 100_000,
2713 excess_data: Vec::new()
2716 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2717 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2718 assert_eq!(route.paths.len(), 1);
2719 assert_eq!(route.paths[0][0].short_channel_id, 12);
2720 let fees = route.paths[0][0].fee_msat;
2721 assert_eq!(fees, 5_000);
2723 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2724 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2725 // the other channel.
2726 assert_eq!(route.paths.len(), 1);
2727 assert_eq!(route.paths[0][0].short_channel_id, 2);
2728 let fees = route.paths[0][0].fee_msat;
2729 assert_eq!(fees, 5_000);
2733 fn disable_channels_test() {
2734 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2735 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2736 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2737 let scorer = test_utils::TestScorer::with_penalty(0);
2738 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2739 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2741 // // Disable channels 4 and 12 by flags=2
2742 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2743 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2744 short_channel_id: 4,
2746 flags: 2, // to disable
2747 cltv_expiry_delta: 0,
2748 htlc_minimum_msat: 0,
2749 htlc_maximum_msat: OptionalField::Absent,
2751 fee_proportional_millionths: 0,
2752 excess_data: Vec::new()
2754 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2755 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2756 short_channel_id: 12,
2758 flags: 2, // to disable
2759 cltv_expiry_delta: 0,
2760 htlc_minimum_msat: 0,
2761 htlc_maximum_msat: OptionalField::Absent,
2763 fee_proportional_millionths: 0,
2764 excess_data: Vec::new()
2767 // If all the channels require some features we don't understand, route should fail
2768 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) {
2769 assert_eq!(err, "Failed to find a path to the given destination");
2770 } else { panic!(); }
2772 // If we specify a channel to node7, that overrides our local channel view and that gets used
2773 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2774 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();
2775 assert_eq!(route.paths[0].len(), 2);
2777 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2778 assert_eq!(route.paths[0][0].short_channel_id, 42);
2779 assert_eq!(route.paths[0][0].fee_msat, 200);
2780 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2781 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2782 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2784 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2785 assert_eq!(route.paths[0][1].short_channel_id, 13);
2786 assert_eq!(route.paths[0][1].fee_msat, 100);
2787 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2788 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2789 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2793 fn disable_node_test() {
2794 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2795 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2796 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2797 let scorer = test_utils::TestScorer::with_penalty(0);
2798 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2799 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2801 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2802 let mut unknown_features = NodeFeatures::known();
2803 unknown_features.set_unknown_feature_required();
2804 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2805 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2806 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2808 // If all nodes require some features we don't understand, route should fail
2809 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) {
2810 assert_eq!(err, "Failed to find a path to the given destination");
2811 } else { panic!(); }
2813 // If we specify a channel to node7, that overrides our local channel view and that gets used
2814 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2815 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();
2816 assert_eq!(route.paths[0].len(), 2);
2818 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2819 assert_eq!(route.paths[0][0].short_channel_id, 42);
2820 assert_eq!(route.paths[0][0].fee_msat, 200);
2821 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2822 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2823 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2825 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2826 assert_eq!(route.paths[0][1].short_channel_id, 13);
2827 assert_eq!(route.paths[0][1].fee_msat, 100);
2828 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2829 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2830 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2832 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2833 // naively) assume that the user checked the feature bits on the invoice, which override
2834 // the node_announcement.
2838 fn our_chans_test() {
2839 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2840 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2841 let scorer = test_utils::TestScorer::with_penalty(0);
2842 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2843 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2845 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2846 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2847 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2848 assert_eq!(route.paths[0].len(), 3);
2850 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2851 assert_eq!(route.paths[0][0].short_channel_id, 2);
2852 assert_eq!(route.paths[0][0].fee_msat, 200);
2853 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2854 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2855 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2857 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2858 assert_eq!(route.paths[0][1].short_channel_id, 4);
2859 assert_eq!(route.paths[0][1].fee_msat, 100);
2860 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2861 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2862 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2864 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2865 assert_eq!(route.paths[0][2].short_channel_id, 3);
2866 assert_eq!(route.paths[0][2].fee_msat, 100);
2867 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2868 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2869 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2871 // If we specify a channel to node7, that overrides our local channel view and that gets used
2872 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2873 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2874 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();
2875 assert_eq!(route.paths[0].len(), 2);
2877 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2878 assert_eq!(route.paths[0][0].short_channel_id, 42);
2879 assert_eq!(route.paths[0][0].fee_msat, 200);
2880 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2881 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2882 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2884 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2885 assert_eq!(route.paths[0][1].short_channel_id, 13);
2886 assert_eq!(route.paths[0][1].fee_msat, 100);
2887 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2888 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2889 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2892 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2893 let zero_fees = RoutingFees {
2895 proportional_millionths: 0,
2897 vec![RouteHint(vec![RouteHintHop {
2898 src_node_id: nodes[3],
2899 short_channel_id: 8,
2901 cltv_expiry_delta: (8 << 4) | 1,
2902 htlc_minimum_msat: None,
2903 htlc_maximum_msat: None,
2905 ]), RouteHint(vec![RouteHintHop {
2906 src_node_id: nodes[4],
2907 short_channel_id: 9,
2910 proportional_millionths: 0,
2912 cltv_expiry_delta: (9 << 4) | 1,
2913 htlc_minimum_msat: None,
2914 htlc_maximum_msat: None,
2915 }]), RouteHint(vec![RouteHintHop {
2916 src_node_id: nodes[5],
2917 short_channel_id: 10,
2919 cltv_expiry_delta: (10 << 4) | 1,
2920 htlc_minimum_msat: None,
2921 htlc_maximum_msat: None,
2925 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2926 let zero_fees = RoutingFees {
2928 proportional_millionths: 0,
2930 vec![RouteHint(vec![RouteHintHop {
2931 src_node_id: nodes[2],
2932 short_channel_id: 5,
2935 proportional_millionths: 0,
2937 cltv_expiry_delta: (5 << 4) | 1,
2938 htlc_minimum_msat: None,
2939 htlc_maximum_msat: None,
2941 src_node_id: nodes[3],
2942 short_channel_id: 8,
2944 cltv_expiry_delta: (8 << 4) | 1,
2945 htlc_minimum_msat: None,
2946 htlc_maximum_msat: None,
2948 ]), RouteHint(vec![RouteHintHop {
2949 src_node_id: nodes[4],
2950 short_channel_id: 9,
2953 proportional_millionths: 0,
2955 cltv_expiry_delta: (9 << 4) | 1,
2956 htlc_minimum_msat: None,
2957 htlc_maximum_msat: None,
2958 }]), RouteHint(vec![RouteHintHop {
2959 src_node_id: nodes[5],
2960 short_channel_id: 10,
2962 cltv_expiry_delta: (10 << 4) | 1,
2963 htlc_minimum_msat: None,
2964 htlc_maximum_msat: None,
2969 fn partial_route_hint_test() {
2970 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2971 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2972 let scorer = test_utils::TestScorer::with_penalty(0);
2973 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2974 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2976 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2977 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2978 // RouteHint may be partially used by the algo to build the best path.
2980 // First check that last hop can't have its source as the payee.
2981 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2982 src_node_id: nodes[6],
2983 short_channel_id: 8,
2986 proportional_millionths: 0,
2988 cltv_expiry_delta: (8 << 4) | 1,
2989 htlc_minimum_msat: None,
2990 htlc_maximum_msat: None,
2993 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
2994 invalid_last_hops.push(invalid_last_hop);
2996 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
2997 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) {
2998 assert_eq!(err, "Route hint cannot have the payee as the source.");
2999 } else { panic!(); }
3002 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
3003 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3004 assert_eq!(route.paths[0].len(), 5);
3006 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3007 assert_eq!(route.paths[0][0].short_channel_id, 2);
3008 assert_eq!(route.paths[0][0].fee_msat, 100);
3009 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3010 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3011 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3013 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3014 assert_eq!(route.paths[0][1].short_channel_id, 4);
3015 assert_eq!(route.paths[0][1].fee_msat, 0);
3016 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3017 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3018 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3020 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3021 assert_eq!(route.paths[0][2].short_channel_id, 6);
3022 assert_eq!(route.paths[0][2].fee_msat, 0);
3023 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3024 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3025 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3027 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3028 assert_eq!(route.paths[0][3].short_channel_id, 11);
3029 assert_eq!(route.paths[0][3].fee_msat, 0);
3030 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3031 // If we have a peer in the node map, we'll use their features here since we don't have
3032 // a way of figuring out their features from the invoice:
3033 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3034 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3036 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3037 assert_eq!(route.paths[0][4].short_channel_id, 8);
3038 assert_eq!(route.paths[0][4].fee_msat, 100);
3039 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3040 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3041 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3044 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3045 let zero_fees = RoutingFees {
3047 proportional_millionths: 0,
3049 vec![RouteHint(vec![RouteHintHop {
3050 src_node_id: nodes[3],
3051 short_channel_id: 8,
3053 cltv_expiry_delta: (8 << 4) | 1,
3054 htlc_minimum_msat: None,
3055 htlc_maximum_msat: None,
3056 }]), RouteHint(vec![
3058 ]), RouteHint(vec![RouteHintHop {
3059 src_node_id: nodes[5],
3060 short_channel_id: 10,
3062 cltv_expiry_delta: (10 << 4) | 1,
3063 htlc_minimum_msat: None,
3064 htlc_maximum_msat: None,
3069 fn ignores_empty_last_hops_test() {
3070 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3071 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3072 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
3073 let scorer = test_utils::TestScorer::with_penalty(0);
3074 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3075 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3077 // Test handling of an empty RouteHint passed in Invoice.
3079 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3080 assert_eq!(route.paths[0].len(), 5);
3082 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3083 assert_eq!(route.paths[0][0].short_channel_id, 2);
3084 assert_eq!(route.paths[0][0].fee_msat, 100);
3085 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3086 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3087 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3089 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3090 assert_eq!(route.paths[0][1].short_channel_id, 4);
3091 assert_eq!(route.paths[0][1].fee_msat, 0);
3092 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3093 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3094 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3096 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3097 assert_eq!(route.paths[0][2].short_channel_id, 6);
3098 assert_eq!(route.paths[0][2].fee_msat, 0);
3099 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3100 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3101 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3103 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3104 assert_eq!(route.paths[0][3].short_channel_id, 11);
3105 assert_eq!(route.paths[0][3].fee_msat, 0);
3106 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3107 // If we have a peer in the node map, we'll use their features here since we don't have
3108 // a way of figuring out their features from the invoice:
3109 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3110 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3112 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3113 assert_eq!(route.paths[0][4].short_channel_id, 8);
3114 assert_eq!(route.paths[0][4].fee_msat, 100);
3115 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3116 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3117 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3120 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3122 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3123 let zero_fees = RoutingFees {
3125 proportional_millionths: 0,
3127 vec![RouteHint(vec![RouteHintHop {
3128 src_node_id: hint_hops[0],
3129 short_channel_id: 0xff00,
3132 proportional_millionths: 0,
3134 cltv_expiry_delta: (5 << 4) | 1,
3135 htlc_minimum_msat: None,
3136 htlc_maximum_msat: None,
3138 src_node_id: hint_hops[1],
3139 short_channel_id: 0xff01,
3141 cltv_expiry_delta: (8 << 4) | 1,
3142 htlc_minimum_msat: None,
3143 htlc_maximum_msat: None,
3148 fn multi_hint_last_hops_test() {
3149 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3150 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3151 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3152 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3153 let scorer = test_utils::TestScorer::with_penalty(0);
3154 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3155 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3156 // Test through channels 2, 3, 0xff00, 0xff01.
3157 // Test shows that multiple hop hints are considered.
3159 // Disabling channels 6 & 7 by flags=2
3160 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3161 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3162 short_channel_id: 6,
3164 flags: 2, // to disable
3165 cltv_expiry_delta: 0,
3166 htlc_minimum_msat: 0,
3167 htlc_maximum_msat: OptionalField::Absent,
3169 fee_proportional_millionths: 0,
3170 excess_data: Vec::new()
3172 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3173 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3174 short_channel_id: 7,
3176 flags: 2, // to disable
3177 cltv_expiry_delta: 0,
3178 htlc_minimum_msat: 0,
3179 htlc_maximum_msat: OptionalField::Absent,
3181 fee_proportional_millionths: 0,
3182 excess_data: Vec::new()
3185 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3186 assert_eq!(route.paths[0].len(), 4);
3188 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3189 assert_eq!(route.paths[0][0].short_channel_id, 2);
3190 assert_eq!(route.paths[0][0].fee_msat, 200);
3191 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3192 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3193 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3195 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3196 assert_eq!(route.paths[0][1].short_channel_id, 4);
3197 assert_eq!(route.paths[0][1].fee_msat, 100);
3198 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3199 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3200 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3202 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
3203 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3204 assert_eq!(route.paths[0][2].fee_msat, 0);
3205 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3206 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
3207 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3209 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3210 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3211 assert_eq!(route.paths[0][3].fee_msat, 100);
3212 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3213 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3214 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3218 fn private_multi_hint_last_hops_test() {
3219 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3220 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3222 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3223 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3225 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3226 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3227 let scorer = test_utils::TestScorer::with_penalty(0);
3228 // Test through channels 2, 3, 0xff00, 0xff01.
3229 // Test shows that multiple hop hints are considered.
3231 // Disabling channels 6 & 7 by flags=2
3232 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3233 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3234 short_channel_id: 6,
3236 flags: 2, // to disable
3237 cltv_expiry_delta: 0,
3238 htlc_minimum_msat: 0,
3239 htlc_maximum_msat: OptionalField::Absent,
3241 fee_proportional_millionths: 0,
3242 excess_data: Vec::new()
3244 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3245 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3246 short_channel_id: 7,
3248 flags: 2, // to disable
3249 cltv_expiry_delta: 0,
3250 htlc_minimum_msat: 0,
3251 htlc_maximum_msat: OptionalField::Absent,
3253 fee_proportional_millionths: 0,
3254 excess_data: Vec::new()
3257 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3258 assert_eq!(route.paths[0].len(), 4);
3260 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3261 assert_eq!(route.paths[0][0].short_channel_id, 2);
3262 assert_eq!(route.paths[0][0].fee_msat, 200);
3263 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3264 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3265 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3267 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3268 assert_eq!(route.paths[0][1].short_channel_id, 4);
3269 assert_eq!(route.paths[0][1].fee_msat, 100);
3270 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3271 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3272 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3274 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
3275 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3276 assert_eq!(route.paths[0][2].fee_msat, 0);
3277 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3278 assert_eq!(route.paths[0][2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3279 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3281 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3282 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3283 assert_eq!(route.paths[0][3].fee_msat, 100);
3284 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3285 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3286 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3289 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3290 let zero_fees = RoutingFees {
3292 proportional_millionths: 0,
3294 vec![RouteHint(vec![RouteHintHop {
3295 src_node_id: nodes[4],
3296 short_channel_id: 11,
3298 cltv_expiry_delta: (11 << 4) | 1,
3299 htlc_minimum_msat: None,
3300 htlc_maximum_msat: None,
3302 src_node_id: nodes[3],
3303 short_channel_id: 8,
3305 cltv_expiry_delta: (8 << 4) | 1,
3306 htlc_minimum_msat: None,
3307 htlc_maximum_msat: None,
3308 }]), RouteHint(vec![RouteHintHop {
3309 src_node_id: nodes[4],
3310 short_channel_id: 9,
3313 proportional_millionths: 0,
3315 cltv_expiry_delta: (9 << 4) | 1,
3316 htlc_minimum_msat: None,
3317 htlc_maximum_msat: None,
3318 }]), RouteHint(vec![RouteHintHop {
3319 src_node_id: nodes[5],
3320 short_channel_id: 10,
3322 cltv_expiry_delta: (10 << 4) | 1,
3323 htlc_minimum_msat: None,
3324 htlc_maximum_msat: None,
3329 fn last_hops_with_public_channel_test() {
3330 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3331 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3332 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3333 let scorer = test_utils::TestScorer::with_penalty(0);
3334 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3335 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3336 // This test shows that public routes can be present in the invoice
3337 // which would be handled in the same manner.
3339 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3340 assert_eq!(route.paths[0].len(), 5);
3342 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3343 assert_eq!(route.paths[0][0].short_channel_id, 2);
3344 assert_eq!(route.paths[0][0].fee_msat, 100);
3345 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3346 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3347 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3349 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3350 assert_eq!(route.paths[0][1].short_channel_id, 4);
3351 assert_eq!(route.paths[0][1].fee_msat, 0);
3352 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3353 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3354 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3356 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3357 assert_eq!(route.paths[0][2].short_channel_id, 6);
3358 assert_eq!(route.paths[0][2].fee_msat, 0);
3359 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3360 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3361 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3363 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3364 assert_eq!(route.paths[0][3].short_channel_id, 11);
3365 assert_eq!(route.paths[0][3].fee_msat, 0);
3366 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3367 // If we have a peer in the node map, we'll use their features here since we don't have
3368 // a way of figuring out their features from the invoice:
3369 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3370 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3372 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3373 assert_eq!(route.paths[0][4].short_channel_id, 8);
3374 assert_eq!(route.paths[0][4].fee_msat, 100);
3375 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3376 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3377 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3381 fn our_chans_last_hop_connect_test() {
3382 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3383 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3384 let scorer = test_utils::TestScorer::with_penalty(0);
3385 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3386 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3388 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3389 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3390 let mut last_hops = last_hops(&nodes);
3391 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3392 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();
3393 assert_eq!(route.paths[0].len(), 2);
3395 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3396 assert_eq!(route.paths[0][0].short_channel_id, 42);
3397 assert_eq!(route.paths[0][0].fee_msat, 0);
3398 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3399 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3400 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3402 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3403 assert_eq!(route.paths[0][1].short_channel_id, 8);
3404 assert_eq!(route.paths[0][1].fee_msat, 100);
3405 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3406 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3407 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3409 last_hops[0].0[0].fees.base_msat = 1000;
3411 // Revert to via 6 as the fee on 8 goes up
3412 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3413 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3414 assert_eq!(route.paths[0].len(), 4);
3416 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3417 assert_eq!(route.paths[0][0].short_channel_id, 2);
3418 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3419 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3420 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3421 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3423 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3424 assert_eq!(route.paths[0][1].short_channel_id, 4);
3425 assert_eq!(route.paths[0][1].fee_msat, 100);
3426 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3427 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3428 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3430 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3431 assert_eq!(route.paths[0][2].short_channel_id, 7);
3432 assert_eq!(route.paths[0][2].fee_msat, 0);
3433 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3434 // If we have a peer in the node map, we'll use their features here since we don't have
3435 // a way of figuring out their features from the invoice:
3436 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3437 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3439 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3440 assert_eq!(route.paths[0][3].short_channel_id, 10);
3441 assert_eq!(route.paths[0][3].fee_msat, 100);
3442 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3443 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3444 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3446 // ...but still use 8 for larger payments as 6 has a variable feerate
3447 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3448 assert_eq!(route.paths[0].len(), 5);
3450 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3451 assert_eq!(route.paths[0][0].short_channel_id, 2);
3452 assert_eq!(route.paths[0][0].fee_msat, 3000);
3453 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3454 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3455 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3457 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3458 assert_eq!(route.paths[0][1].short_channel_id, 4);
3459 assert_eq!(route.paths[0][1].fee_msat, 0);
3460 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3461 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3462 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3464 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3465 assert_eq!(route.paths[0][2].short_channel_id, 6);
3466 assert_eq!(route.paths[0][2].fee_msat, 0);
3467 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3468 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3469 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3471 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3472 assert_eq!(route.paths[0][3].short_channel_id, 11);
3473 assert_eq!(route.paths[0][3].fee_msat, 1000);
3474 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3475 // If we have a peer in the node map, we'll use their features here since we don't have
3476 // a way of figuring out their features from the invoice:
3477 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3478 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3480 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3481 assert_eq!(route.paths[0][4].short_channel_id, 8);
3482 assert_eq!(route.paths[0][4].fee_msat, 2000);
3483 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3484 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3485 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3488 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> {
3489 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3490 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3491 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3493 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3494 let last_hops = RouteHint(vec![RouteHintHop {
3495 src_node_id: middle_node_id,
3496 short_channel_id: 8,
3499 proportional_millionths: last_hop_fee_prop,
3501 cltv_expiry_delta: (8 << 4) | 1,
3502 htlc_minimum_msat: None,
3503 htlc_maximum_msat: last_hop_htlc_max,
3505 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3506 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3507 let scorer = test_utils::TestScorer::with_penalty(0);
3508 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3509 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3510 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
3511 let logger = test_utils::TestLogger::new();
3512 let network_graph = NetworkGraph::new(genesis_hash, &logger);
3513 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3514 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &logger, &scorer, &random_seed_bytes);
3519 fn unannounced_path_test() {
3520 // We should be able to send a payment to a destination without any help of a routing graph
3521 // if we have a channel with a common counterparty that appears in the first and last hop
3523 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3525 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3526 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3527 assert_eq!(route.paths[0].len(), 2);
3529 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3530 assert_eq!(route.paths[0][0].short_channel_id, 42);
3531 assert_eq!(route.paths[0][0].fee_msat, 1001);
3532 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3533 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3534 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3536 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3537 assert_eq!(route.paths[0][1].short_channel_id, 8);
3538 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3539 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3540 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3541 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3545 fn overflow_unannounced_path_test_liquidity_underflow() {
3546 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3547 // the last-hop had a fee which overflowed a u64, we'd panic.
3548 // This was due to us adding the first-hop from us unconditionally, causing us to think
3549 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3550 // In this test, we previously hit a subtraction underflow due to having less available
3551 // liquidity at the last hop than 0.
3552 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());
3556 fn overflow_unannounced_path_test_feerate_overflow() {
3557 // This tests for the same case as above, except instead of hitting a subtraction
3558 // underflow, we hit a case where the fee charged at a hop overflowed.
3559 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());
3563 fn available_amount_while_routing_test() {
3564 // Tests whether we choose the correct available channel amount while routing.
3566 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3567 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3568 let scorer = test_utils::TestScorer::with_penalty(0);
3569 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3570 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3571 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3573 // We will use a simple single-path route from
3574 // our node to node2 via node0: channels {1, 3}.
3576 // First disable all other paths.
3577 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3578 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3579 short_channel_id: 2,
3582 cltv_expiry_delta: 0,
3583 htlc_minimum_msat: 0,
3584 htlc_maximum_msat: OptionalField::Present(100_000),
3586 fee_proportional_millionths: 0,
3587 excess_data: Vec::new()
3589 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3590 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3591 short_channel_id: 12,
3594 cltv_expiry_delta: 0,
3595 htlc_minimum_msat: 0,
3596 htlc_maximum_msat: OptionalField::Present(100_000),
3598 fee_proportional_millionths: 0,
3599 excess_data: Vec::new()
3602 // Make the first channel (#1) very permissive,
3603 // and we will be testing all limits on the second channel.
3604 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3605 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3606 short_channel_id: 1,
3609 cltv_expiry_delta: 0,
3610 htlc_minimum_msat: 0,
3611 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3613 fee_proportional_millionths: 0,
3614 excess_data: Vec::new()
3617 // First, let's see if routing works if we have absolutely no idea about the available amount.
3618 // In this case, it should be set to 250_000 sats.
3619 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3620 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3621 short_channel_id: 3,
3624 cltv_expiry_delta: 0,
3625 htlc_minimum_msat: 0,
3626 htlc_maximum_msat: OptionalField::Absent,
3628 fee_proportional_millionths: 0,
3629 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, 250_000_001, 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 an exact amount we have should be fine.
3642 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();
3643 assert_eq!(route.paths.len(), 1);
3644 let path = route.paths.last().unwrap();
3645 assert_eq!(path.len(), 2);
3646 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3647 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3650 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3651 // Disable channel #1 and use another first hop.
3652 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3653 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3654 short_channel_id: 1,
3657 cltv_expiry_delta: 0,
3658 htlc_minimum_msat: 0,
3659 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3661 fee_proportional_millionths: 0,
3662 excess_data: Vec::new()
3665 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3666 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3669 // Attempt to route more than available results in a failure.
3670 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3671 &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) {
3672 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3673 } else { panic!(); }
3677 // Now, attempt to route an exact amount we have should be fine.
3678 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();
3679 assert_eq!(route.paths.len(), 1);
3680 let path = route.paths.last().unwrap();
3681 assert_eq!(path.len(), 2);
3682 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3683 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3686 // Enable channel #1 back.
3687 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3688 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3689 short_channel_id: 1,
3692 cltv_expiry_delta: 0,
3693 htlc_minimum_msat: 0,
3694 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3696 fee_proportional_millionths: 0,
3697 excess_data: Vec::new()
3701 // Now let's see if routing works if we know only htlc_maximum_msat.
3702 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3703 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3704 short_channel_id: 3,
3707 cltv_expiry_delta: 0,
3708 htlc_minimum_msat: 0,
3709 htlc_maximum_msat: OptionalField::Present(15_000),
3711 fee_proportional_millionths: 0,
3712 excess_data: Vec::new()
3716 // Attempt to route more than available results in a failure.
3717 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3718 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3719 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3720 } else { panic!(); }
3724 // Now, attempt to route an exact amount we have should be fine.
3725 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3726 assert_eq!(route.paths.len(), 1);
3727 let path = route.paths.last().unwrap();
3728 assert_eq!(path.len(), 2);
3729 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3730 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3733 // Now let's see if routing works if we know only capacity from the UTXO.
3735 // We can't change UTXO capacity on the fly, so we'll disable
3736 // the existing channel and add another one with the capacity we need.
3737 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3738 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3739 short_channel_id: 3,
3742 cltv_expiry_delta: 0,
3743 htlc_minimum_msat: 0,
3744 htlc_maximum_msat: OptionalField::Absent,
3746 fee_proportional_millionths: 0,
3747 excess_data: Vec::new()
3750 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3751 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3752 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3753 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3754 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3756 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3757 gossip_sync.add_chain_access(Some(chain_monitor));
3759 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3760 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3761 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3762 short_channel_id: 333,
3765 cltv_expiry_delta: (3 << 4) | 1,
3766 htlc_minimum_msat: 0,
3767 htlc_maximum_msat: OptionalField::Absent,
3769 fee_proportional_millionths: 0,
3770 excess_data: Vec::new()
3772 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3773 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3774 short_channel_id: 333,
3777 cltv_expiry_delta: (3 << 4) | 2,
3778 htlc_minimum_msat: 0,
3779 htlc_maximum_msat: OptionalField::Absent,
3781 fee_proportional_millionths: 0,
3782 excess_data: Vec::new()
3786 // Attempt to route more than available results in a failure.
3787 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3788 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3789 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3790 } else { panic!(); }
3794 // Now, attempt to route an exact amount we have should be fine.
3795 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3796 assert_eq!(route.paths.len(), 1);
3797 let path = route.paths.last().unwrap();
3798 assert_eq!(path.len(), 2);
3799 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3800 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3803 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3804 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3805 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3806 short_channel_id: 333,
3809 cltv_expiry_delta: 0,
3810 htlc_minimum_msat: 0,
3811 htlc_maximum_msat: OptionalField::Present(10_000),
3813 fee_proportional_millionths: 0,
3814 excess_data: Vec::new()
3818 // Attempt to route more than available results in a failure.
3819 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3820 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3821 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3822 } else { panic!(); }
3826 // Now, attempt to route an exact amount we have should be fine.
3827 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3828 assert_eq!(route.paths.len(), 1);
3829 let path = route.paths.last().unwrap();
3830 assert_eq!(path.len(), 2);
3831 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3832 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3837 fn available_liquidity_last_hop_test() {
3838 // Check that available liquidity properly limits the path even when only
3839 // one of the latter hops is limited.
3840 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3841 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3842 let scorer = test_utils::TestScorer::with_penalty(0);
3843 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3844 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3845 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3847 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3848 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3849 // Total capacity: 50 sats.
3851 // Disable other potential paths.
3852 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3853 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3854 short_channel_id: 2,
3857 cltv_expiry_delta: 0,
3858 htlc_minimum_msat: 0,
3859 htlc_maximum_msat: OptionalField::Present(100_000),
3861 fee_proportional_millionths: 0,
3862 excess_data: Vec::new()
3864 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3865 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3866 short_channel_id: 7,
3869 cltv_expiry_delta: 0,
3870 htlc_minimum_msat: 0,
3871 htlc_maximum_msat: OptionalField::Present(100_000),
3873 fee_proportional_millionths: 0,
3874 excess_data: Vec::new()
3879 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3880 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3881 short_channel_id: 12,
3884 cltv_expiry_delta: 0,
3885 htlc_minimum_msat: 0,
3886 htlc_maximum_msat: OptionalField::Present(100_000),
3888 fee_proportional_millionths: 0,
3889 excess_data: Vec::new()
3891 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3892 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3893 short_channel_id: 13,
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()
3904 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3905 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3906 short_channel_id: 6,
3909 cltv_expiry_delta: 0,
3910 htlc_minimum_msat: 0,
3911 htlc_maximum_msat: OptionalField::Present(50_000),
3913 fee_proportional_millionths: 0,
3914 excess_data: Vec::new()
3916 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3917 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3918 short_channel_id: 11,
3921 cltv_expiry_delta: 0,
3922 htlc_minimum_msat: 0,
3923 htlc_maximum_msat: OptionalField::Present(100_000),
3925 fee_proportional_millionths: 0,
3926 excess_data: Vec::new()
3929 // Attempt to route more than available results in a failure.
3930 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3931 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3932 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3933 } else { panic!(); }
3937 // Now, attempt to route 49 sats (just a bit below the capacity).
3938 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3939 assert_eq!(route.paths.len(), 1);
3940 let mut total_amount_paid_msat = 0;
3941 for path in &route.paths {
3942 assert_eq!(path.len(), 4);
3943 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3944 total_amount_paid_msat += path.last().unwrap().fee_msat;
3946 assert_eq!(total_amount_paid_msat, 49_000);
3950 // Attempt to route an exact amount is also fine
3951 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3952 assert_eq!(route.paths.len(), 1);
3953 let mut total_amount_paid_msat = 0;
3954 for path in &route.paths {
3955 assert_eq!(path.len(), 4);
3956 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3957 total_amount_paid_msat += path.last().unwrap().fee_msat;
3959 assert_eq!(total_amount_paid_msat, 50_000);
3964 fn ignore_fee_first_hop_test() {
3965 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3966 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3967 let scorer = test_utils::TestScorer::with_penalty(0);
3968 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3969 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3970 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3972 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3973 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3974 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3975 short_channel_id: 1,
3978 cltv_expiry_delta: 0,
3979 htlc_minimum_msat: 0,
3980 htlc_maximum_msat: OptionalField::Present(100_000),
3981 fee_base_msat: 1_000_000,
3982 fee_proportional_millionths: 0,
3983 excess_data: Vec::new()
3985 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3986 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3987 short_channel_id: 3,
3990 cltv_expiry_delta: 0,
3991 htlc_minimum_msat: 0,
3992 htlc_maximum_msat: OptionalField::Present(50_000),
3994 fee_proportional_millionths: 0,
3995 excess_data: Vec::new()
3999 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4000 assert_eq!(route.paths.len(), 1);
4001 let mut total_amount_paid_msat = 0;
4002 for path in &route.paths {
4003 assert_eq!(path.len(), 2);
4004 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4005 total_amount_paid_msat += path.last().unwrap().fee_msat;
4007 assert_eq!(total_amount_paid_msat, 50_000);
4012 fn simple_mpp_route_test() {
4013 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4014 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4015 let scorer = test_utils::TestScorer::with_penalty(0);
4016 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4017 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4018 let payment_params = PaymentParameters::from_node_id(nodes[2])
4019 .with_features(InvoiceFeatures::known());
4021 // We need a route consisting of 3 paths:
4022 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4023 // To achieve this, the amount being transferred should be around
4024 // the total capacity of these 3 paths.
4026 // First, we set limits on these (previously unlimited) channels.
4027 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4029 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4030 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4031 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4032 short_channel_id: 1,
4035 cltv_expiry_delta: 0,
4036 htlc_minimum_msat: 0,
4037 htlc_maximum_msat: OptionalField::Present(100_000),
4039 fee_proportional_millionths: 0,
4040 excess_data: Vec::new()
4042 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4043 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4044 short_channel_id: 3,
4047 cltv_expiry_delta: 0,
4048 htlc_minimum_msat: 0,
4049 htlc_maximum_msat: OptionalField::Present(50_000),
4051 fee_proportional_millionths: 0,
4052 excess_data: Vec::new()
4055 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4056 // (total limit 60).
4057 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4058 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4059 short_channel_id: 12,
4062 cltv_expiry_delta: 0,
4063 htlc_minimum_msat: 0,
4064 htlc_maximum_msat: OptionalField::Present(60_000),
4066 fee_proportional_millionths: 0,
4067 excess_data: Vec::new()
4069 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4070 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4071 short_channel_id: 13,
4074 cltv_expiry_delta: 0,
4075 htlc_minimum_msat: 0,
4076 htlc_maximum_msat: OptionalField::Present(60_000),
4078 fee_proportional_millionths: 0,
4079 excess_data: Vec::new()
4082 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4083 // (total capacity 180 sats).
4084 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4085 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4086 short_channel_id: 2,
4089 cltv_expiry_delta: 0,
4090 htlc_minimum_msat: 0,
4091 htlc_maximum_msat: OptionalField::Present(200_000),
4093 fee_proportional_millionths: 0,
4094 excess_data: Vec::new()
4096 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4097 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4098 short_channel_id: 4,
4101 cltv_expiry_delta: 0,
4102 htlc_minimum_msat: 0,
4103 htlc_maximum_msat: OptionalField::Present(180_000),
4105 fee_proportional_millionths: 0,
4106 excess_data: Vec::new()
4110 // Attempt to route more than available results in a failure.
4111 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4112 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42,
4113 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4114 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4115 } else { panic!(); }
4119 // Attempt to route while setting max_mpp_path_count to 0 results in a failure.
4120 let zero_payment_params = payment_params.clone().with_max_mpp_path_count(0);
4121 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4122 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100, 42,
4123 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4124 assert_eq!(err, "Can't find an MPP route with no paths allowed.");
4125 } else { panic!(); }
4129 // Attempt to route while setting max_mpp_path_count to 3 results in a failure.
4130 // This is the case because the minimal_value_contribution_msat would require each path
4131 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4132 let fail_payment_params = payment_params.clone().with_max_mpp_path_count(3);
4133 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4134 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000, 42,
4135 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4136 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4137 } else { panic!(); }
4141 // Now, attempt to route 250 sats (just a bit below the capacity).
4142 // Our algorithm should provide us with these 3 paths.
4143 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4144 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4145 assert_eq!(route.paths.len(), 3);
4146 let mut total_amount_paid_msat = 0;
4147 for path in &route.paths {
4148 assert_eq!(path.len(), 2);
4149 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4150 total_amount_paid_msat += path.last().unwrap().fee_msat;
4152 assert_eq!(total_amount_paid_msat, 250_000);
4156 // Attempt to route an exact amount is also fine
4157 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4158 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4159 assert_eq!(route.paths.len(), 3);
4160 let mut total_amount_paid_msat = 0;
4161 for path in &route.paths {
4162 assert_eq!(path.len(), 2);
4163 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4164 total_amount_paid_msat += path.last().unwrap().fee_msat;
4166 assert_eq!(total_amount_paid_msat, 290_000);
4171 fn long_mpp_route_test() {
4172 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4173 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4174 let scorer = test_utils::TestScorer::with_penalty(0);
4175 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4176 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4177 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4179 // We need a route consisting of 3 paths:
4180 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4181 // Note that these paths overlap (channels 5, 12, 13).
4182 // We will route 300 sats.
4183 // Each path will have 100 sats capacity, those channels which
4184 // are used twice will have 200 sats capacity.
4186 // Disable other potential paths.
4187 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4188 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4189 short_channel_id: 2,
4192 cltv_expiry_delta: 0,
4193 htlc_minimum_msat: 0,
4194 htlc_maximum_msat: OptionalField::Present(100_000),
4196 fee_proportional_millionths: 0,
4197 excess_data: Vec::new()
4199 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4200 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4201 short_channel_id: 7,
4204 cltv_expiry_delta: 0,
4205 htlc_minimum_msat: 0,
4206 htlc_maximum_msat: OptionalField::Present(100_000),
4208 fee_proportional_millionths: 0,
4209 excess_data: Vec::new()
4212 // Path via {node0, node2} is channels {1, 3, 5}.
4213 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4214 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4215 short_channel_id: 1,
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()
4225 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4226 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4227 short_channel_id: 3,
4230 cltv_expiry_delta: 0,
4231 htlc_minimum_msat: 0,
4232 htlc_maximum_msat: OptionalField::Present(100_000),
4234 fee_proportional_millionths: 0,
4235 excess_data: Vec::new()
4238 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4239 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4240 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4241 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4242 short_channel_id: 5,
4245 cltv_expiry_delta: 0,
4246 htlc_minimum_msat: 0,
4247 htlc_maximum_msat: OptionalField::Present(200_000),
4249 fee_proportional_millionths: 0,
4250 excess_data: Vec::new()
4253 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4254 // Add 100 sats to the capacities of {12, 13}, because these channels
4255 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4256 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4257 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4258 short_channel_id: 12,
4261 cltv_expiry_delta: 0,
4262 htlc_minimum_msat: 0,
4263 htlc_maximum_msat: OptionalField::Present(200_000),
4265 fee_proportional_millionths: 0,
4266 excess_data: Vec::new()
4268 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4269 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4270 short_channel_id: 13,
4273 cltv_expiry_delta: 0,
4274 htlc_minimum_msat: 0,
4275 htlc_maximum_msat: OptionalField::Present(200_000),
4277 fee_proportional_millionths: 0,
4278 excess_data: Vec::new()
4281 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4282 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4283 short_channel_id: 6,
4286 cltv_expiry_delta: 0,
4287 htlc_minimum_msat: 0,
4288 htlc_maximum_msat: OptionalField::Present(100_000),
4290 fee_proportional_millionths: 0,
4291 excess_data: Vec::new()
4293 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4294 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4295 short_channel_id: 11,
4298 cltv_expiry_delta: 0,
4299 htlc_minimum_msat: 0,
4300 htlc_maximum_msat: OptionalField::Present(100_000),
4302 fee_proportional_millionths: 0,
4303 excess_data: Vec::new()
4306 // Path via {node7, node2} is channels {12, 13, 5}.
4307 // We already limited them to 200 sats (they are used twice for 100 sats).
4308 // Nothing to do here.
4311 // Attempt to route more than available results in a failure.
4312 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4313 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4314 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4315 } else { panic!(); }
4319 // Now, attempt to route 300 sats (exact amount we can route).
4320 // Our algorithm should provide us with these 3 paths, 100 sats each.
4321 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4322 assert_eq!(route.paths.len(), 3);
4324 let mut total_amount_paid_msat = 0;
4325 for path in &route.paths {
4326 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4327 total_amount_paid_msat += path.last().unwrap().fee_msat;
4329 assert_eq!(total_amount_paid_msat, 300_000);
4335 fn mpp_cheaper_route_test() {
4336 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4337 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4338 let scorer = test_utils::TestScorer::with_penalty(0);
4339 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4340 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4341 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4343 // This test checks that if we have two cheaper paths and one more expensive path,
4344 // so that liquidity-wise any 2 of 3 combination is sufficient,
4345 // two cheaper paths will be taken.
4346 // These paths have equal available liquidity.
4348 // We need a combination of 3 paths:
4349 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4350 // Note that these paths overlap (channels 5, 12, 13).
4351 // Each path will have 100 sats capacity, those channels which
4352 // are used twice will have 200 sats capacity.
4354 // Disable other potential paths.
4355 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4356 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4357 short_channel_id: 2,
4360 cltv_expiry_delta: 0,
4361 htlc_minimum_msat: 0,
4362 htlc_maximum_msat: OptionalField::Present(100_000),
4364 fee_proportional_millionths: 0,
4365 excess_data: Vec::new()
4367 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4368 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4369 short_channel_id: 7,
4372 cltv_expiry_delta: 0,
4373 htlc_minimum_msat: 0,
4374 htlc_maximum_msat: OptionalField::Present(100_000),
4376 fee_proportional_millionths: 0,
4377 excess_data: Vec::new()
4380 // Path via {node0, node2} is channels {1, 3, 5}.
4381 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4382 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4383 short_channel_id: 1,
4386 cltv_expiry_delta: 0,
4387 htlc_minimum_msat: 0,
4388 htlc_maximum_msat: OptionalField::Present(100_000),
4390 fee_proportional_millionths: 0,
4391 excess_data: Vec::new()
4393 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4394 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4395 short_channel_id: 3,
4398 cltv_expiry_delta: 0,
4399 htlc_minimum_msat: 0,
4400 htlc_maximum_msat: OptionalField::Present(100_000),
4402 fee_proportional_millionths: 0,
4403 excess_data: Vec::new()
4406 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4407 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4408 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4409 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4410 short_channel_id: 5,
4413 cltv_expiry_delta: 0,
4414 htlc_minimum_msat: 0,
4415 htlc_maximum_msat: OptionalField::Present(200_000),
4417 fee_proportional_millionths: 0,
4418 excess_data: Vec::new()
4421 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4422 // Add 100 sats to the capacities of {12, 13}, because these channels
4423 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4424 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4425 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4426 short_channel_id: 12,
4429 cltv_expiry_delta: 0,
4430 htlc_minimum_msat: 0,
4431 htlc_maximum_msat: OptionalField::Present(200_000),
4433 fee_proportional_millionths: 0,
4434 excess_data: Vec::new()
4436 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4437 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4438 short_channel_id: 13,
4441 cltv_expiry_delta: 0,
4442 htlc_minimum_msat: 0,
4443 htlc_maximum_msat: OptionalField::Present(200_000),
4445 fee_proportional_millionths: 0,
4446 excess_data: Vec::new()
4449 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4450 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4451 short_channel_id: 6,
4454 cltv_expiry_delta: 0,
4455 htlc_minimum_msat: 0,
4456 htlc_maximum_msat: OptionalField::Present(100_000),
4457 fee_base_msat: 1_000,
4458 fee_proportional_millionths: 0,
4459 excess_data: Vec::new()
4461 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4462 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4463 short_channel_id: 11,
4466 cltv_expiry_delta: 0,
4467 htlc_minimum_msat: 0,
4468 htlc_maximum_msat: OptionalField::Present(100_000),
4470 fee_proportional_millionths: 0,
4471 excess_data: Vec::new()
4474 // Path via {node7, node2} is channels {12, 13, 5}.
4475 // We already limited them to 200 sats (they are used twice for 100 sats).
4476 // Nothing to do here.
4479 // Now, attempt to route 180 sats.
4480 // Our algorithm should provide us with these 2 paths.
4481 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4482 assert_eq!(route.paths.len(), 2);
4484 let mut total_value_transferred_msat = 0;
4485 let mut total_paid_msat = 0;
4486 for path in &route.paths {
4487 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4488 total_value_transferred_msat += path.last().unwrap().fee_msat;
4490 total_paid_msat += hop.fee_msat;
4493 // If we paid fee, this would be higher.
4494 assert_eq!(total_value_transferred_msat, 180_000);
4495 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4496 assert_eq!(total_fees_paid, 0);
4501 fn fees_on_mpp_route_test() {
4502 // This test makes sure that MPP algorithm properly takes into account
4503 // fees charged on the channels, by making the fees impactful:
4504 // if the fee is not properly accounted for, the behavior is different.
4505 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4506 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4507 let scorer = test_utils::TestScorer::with_penalty(0);
4508 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4509 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4510 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4512 // We need a route consisting of 2 paths:
4513 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4514 // We will route 200 sats, Each path will have 100 sats capacity.
4516 // This test is not particularly stable: e.g.,
4517 // there's a way to route via {node0, node2, node4}.
4518 // It works while pathfinding is deterministic, but can be broken otherwise.
4519 // It's fine to ignore this concern for now.
4521 // Disable other potential paths.
4522 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4523 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4524 short_channel_id: 2,
4527 cltv_expiry_delta: 0,
4528 htlc_minimum_msat: 0,
4529 htlc_maximum_msat: OptionalField::Present(100_000),
4531 fee_proportional_millionths: 0,
4532 excess_data: Vec::new()
4535 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4536 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4537 short_channel_id: 7,
4540 cltv_expiry_delta: 0,
4541 htlc_minimum_msat: 0,
4542 htlc_maximum_msat: OptionalField::Present(100_000),
4544 fee_proportional_millionths: 0,
4545 excess_data: Vec::new()
4548 // Path via {node0, node2} is channels {1, 3, 5}.
4549 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4550 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4551 short_channel_id: 1,
4554 cltv_expiry_delta: 0,
4555 htlc_minimum_msat: 0,
4556 htlc_maximum_msat: OptionalField::Present(100_000),
4558 fee_proportional_millionths: 0,
4559 excess_data: Vec::new()
4561 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4562 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4563 short_channel_id: 3,
4566 cltv_expiry_delta: 0,
4567 htlc_minimum_msat: 0,
4568 htlc_maximum_msat: OptionalField::Present(100_000),
4570 fee_proportional_millionths: 0,
4571 excess_data: Vec::new()
4574 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4575 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4576 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4577 short_channel_id: 5,
4580 cltv_expiry_delta: 0,
4581 htlc_minimum_msat: 0,
4582 htlc_maximum_msat: OptionalField::Present(100_000),
4584 fee_proportional_millionths: 0,
4585 excess_data: Vec::new()
4588 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4589 // All channels should be 100 sats capacity. But for the fee experiment,
4590 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4591 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4592 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4593 // so no matter how large are other channels,
4594 // the whole path will be limited by 100 sats with just these 2 conditions:
4595 // - channel 12 capacity is 250 sats
4596 // - fee for channel 6 is 150 sats
4597 // Let's test this by enforcing these 2 conditions and removing other limits.
4598 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4599 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4600 short_channel_id: 12,
4603 cltv_expiry_delta: 0,
4604 htlc_minimum_msat: 0,
4605 htlc_maximum_msat: OptionalField::Present(250_000),
4607 fee_proportional_millionths: 0,
4608 excess_data: Vec::new()
4610 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4611 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4612 short_channel_id: 13,
4615 cltv_expiry_delta: 0,
4616 htlc_minimum_msat: 0,
4617 htlc_maximum_msat: OptionalField::Absent,
4619 fee_proportional_millionths: 0,
4620 excess_data: Vec::new()
4623 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4624 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4625 short_channel_id: 6,
4628 cltv_expiry_delta: 0,
4629 htlc_minimum_msat: 0,
4630 htlc_maximum_msat: OptionalField::Absent,
4631 fee_base_msat: 150_000,
4632 fee_proportional_millionths: 0,
4633 excess_data: Vec::new()
4635 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4636 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4637 short_channel_id: 11,
4640 cltv_expiry_delta: 0,
4641 htlc_minimum_msat: 0,
4642 htlc_maximum_msat: OptionalField::Absent,
4644 fee_proportional_millionths: 0,
4645 excess_data: Vec::new()
4649 // Attempt to route more than available results in a failure.
4650 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4651 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4652 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4653 } else { panic!(); }
4657 // Now, attempt to route 200 sats (exact amount we can route).
4658 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4659 assert_eq!(route.paths.len(), 2);
4661 let mut total_amount_paid_msat = 0;
4662 for path in &route.paths {
4663 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4664 total_amount_paid_msat += path.last().unwrap().fee_msat;
4666 assert_eq!(total_amount_paid_msat, 200_000);
4667 assert_eq!(route.get_total_fees(), 150_000);
4672 fn mpp_with_last_hops() {
4673 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4674 // via a single last-hop route hint, we'd fail to route if we first collected routes
4675 // totaling close but not quite enough to fund the full payment.
4677 // This was because we considered last-hop hints to have exactly the sought payment amount
4678 // instead of the amount we were trying to collect, needlessly limiting our path searching
4679 // at the very first hop.
4681 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4682 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4683 // to only have the remaining to-collect amount in available liquidity.
4685 // This bug appeared in production in some specific channel configurations.
4686 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4687 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4688 let scorer = test_utils::TestScorer::with_penalty(0);
4689 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4690 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4691 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4692 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4693 src_node_id: nodes[2],
4694 short_channel_id: 42,
4695 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4696 cltv_expiry_delta: 42,
4697 htlc_minimum_msat: None,
4698 htlc_maximum_msat: None,
4701 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4702 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4703 // would first use the no-fee route and then fail to find a path along the second route as
4704 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4705 // under 5% of our payment amount.
4706 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4707 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4708 short_channel_id: 1,
4711 cltv_expiry_delta: (5 << 4) | 5,
4712 htlc_minimum_msat: 0,
4713 htlc_maximum_msat: OptionalField::Present(99_000),
4714 fee_base_msat: u32::max_value(),
4715 fee_proportional_millionths: u32::max_value(),
4716 excess_data: Vec::new()
4718 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4719 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4720 short_channel_id: 2,
4723 cltv_expiry_delta: (5 << 4) | 3,
4724 htlc_minimum_msat: 0,
4725 htlc_maximum_msat: OptionalField::Present(99_000),
4726 fee_base_msat: u32::max_value(),
4727 fee_proportional_millionths: u32::max_value(),
4728 excess_data: Vec::new()
4730 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4731 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4732 short_channel_id: 4,
4735 cltv_expiry_delta: (4 << 4) | 1,
4736 htlc_minimum_msat: 0,
4737 htlc_maximum_msat: OptionalField::Absent,
4739 fee_proportional_millionths: 0,
4740 excess_data: Vec::new()
4742 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4743 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4744 short_channel_id: 13,
4746 flags: 0|2, // Channel disabled
4747 cltv_expiry_delta: (13 << 4) | 1,
4748 htlc_minimum_msat: 0,
4749 htlc_maximum_msat: OptionalField::Absent,
4751 fee_proportional_millionths: 2000000,
4752 excess_data: Vec::new()
4755 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4757 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4758 assert_eq!(route.paths.len(), 2);
4759 // Paths are somewhat randomly ordered, but:
4760 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4761 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4762 assert_eq!(route.paths[0][0].short_channel_id, 2);
4763 assert_eq!(route.paths[0][0].fee_msat, 1);
4764 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4765 assert_eq!(route.paths[1][0].short_channel_id, 1);
4766 assert_eq!(route.paths[1][0].fee_msat, 0);
4767 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4768 assert_eq!(route.get_total_fees(), 1);
4769 assert_eq!(route.get_total_amount(), 100_000);
4773 fn drop_lowest_channel_mpp_route_test() {
4774 // This test checks that low-capacity channel is dropped when after
4775 // path finding we realize that we found more capacity than we need.
4776 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4777 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4778 let scorer = test_utils::TestScorer::with_penalty(0);
4779 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4780 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4781 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4783 // We need a route consisting of 3 paths:
4784 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4786 // The first and the second paths should be sufficient, but the third should be
4787 // cheaper, so that we select it but drop later.
4789 // First, we set limits on these (previously unlimited) channels.
4790 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4792 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4793 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4794 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4795 short_channel_id: 1,
4798 cltv_expiry_delta: 0,
4799 htlc_minimum_msat: 0,
4800 htlc_maximum_msat: OptionalField::Present(100_000),
4802 fee_proportional_millionths: 0,
4803 excess_data: Vec::new()
4805 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4806 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4807 short_channel_id: 3,
4810 cltv_expiry_delta: 0,
4811 htlc_minimum_msat: 0,
4812 htlc_maximum_msat: OptionalField::Present(50_000),
4814 fee_proportional_millionths: 0,
4815 excess_data: Vec::new()
4818 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4819 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4820 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4821 short_channel_id: 12,
4824 cltv_expiry_delta: 0,
4825 htlc_minimum_msat: 0,
4826 htlc_maximum_msat: OptionalField::Present(60_000),
4828 fee_proportional_millionths: 0,
4829 excess_data: Vec::new()
4831 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4832 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4833 short_channel_id: 13,
4836 cltv_expiry_delta: 0,
4837 htlc_minimum_msat: 0,
4838 htlc_maximum_msat: OptionalField::Present(60_000),
4840 fee_proportional_millionths: 0,
4841 excess_data: Vec::new()
4844 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4845 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4846 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4847 short_channel_id: 2,
4850 cltv_expiry_delta: 0,
4851 htlc_minimum_msat: 0,
4852 htlc_maximum_msat: OptionalField::Present(20_000),
4854 fee_proportional_millionths: 0,
4855 excess_data: Vec::new()
4857 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4858 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4859 short_channel_id: 4,
4862 cltv_expiry_delta: 0,
4863 htlc_minimum_msat: 0,
4864 htlc_maximum_msat: OptionalField::Present(20_000),
4866 fee_proportional_millionths: 0,
4867 excess_data: Vec::new()
4871 // Attempt to route more than available results in a failure.
4872 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4873 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4874 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4875 } else { panic!(); }
4879 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4880 // Our algorithm should provide us with these 3 paths.
4881 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4882 assert_eq!(route.paths.len(), 3);
4883 let mut total_amount_paid_msat = 0;
4884 for path in &route.paths {
4885 assert_eq!(path.len(), 2);
4886 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4887 total_amount_paid_msat += path.last().unwrap().fee_msat;
4889 assert_eq!(total_amount_paid_msat, 125_000);
4893 // Attempt to route without the last small cheap channel
4894 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4895 assert_eq!(route.paths.len(), 2);
4896 let mut total_amount_paid_msat = 0;
4897 for path in &route.paths {
4898 assert_eq!(path.len(), 2);
4899 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4900 total_amount_paid_msat += path.last().unwrap().fee_msat;
4902 assert_eq!(total_amount_paid_msat, 90_000);
4907 fn min_criteria_consistency() {
4908 // Test that we don't use an inconsistent metric between updating and walking nodes during
4909 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4910 // was updated with a different criterion from the heap sorting, resulting in loops in
4911 // calculated paths. We test for that specific case here.
4913 // We construct a network that looks like this:
4915 // node2 -1(3)2- node3
4919 // node1 -1(5)2- node4 -1(1)2- node6
4925 // We create a loop on the side of our real path - our destination is node 6, with a
4926 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4927 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4928 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4929 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4930 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4931 // "previous hop" being set to node 3, creating a loop in the path.
4932 let secp_ctx = Secp256k1::new();
4933 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
4934 let logger = Arc::new(test_utils::TestLogger::new());
4935 let network = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
4936 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
4937 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4938 let scorer = test_utils::TestScorer::with_penalty(0);
4939 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4940 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4941 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4943 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4944 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4945 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4946 short_channel_id: 6,
4949 cltv_expiry_delta: (6 << 4) | 0,
4950 htlc_minimum_msat: 0,
4951 htlc_maximum_msat: OptionalField::Absent,
4953 fee_proportional_millionths: 0,
4954 excess_data: Vec::new()
4956 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4958 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4959 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4960 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4961 short_channel_id: 5,
4964 cltv_expiry_delta: (5 << 4) | 0,
4965 htlc_minimum_msat: 0,
4966 htlc_maximum_msat: OptionalField::Absent,
4968 fee_proportional_millionths: 0,
4969 excess_data: Vec::new()
4971 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4973 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4974 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4975 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4976 short_channel_id: 4,
4979 cltv_expiry_delta: (4 << 4) | 0,
4980 htlc_minimum_msat: 0,
4981 htlc_maximum_msat: OptionalField::Absent,
4983 fee_proportional_millionths: 0,
4984 excess_data: Vec::new()
4986 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4988 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4989 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4990 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4991 short_channel_id: 3,
4994 cltv_expiry_delta: (3 << 4) | 0,
4995 htlc_minimum_msat: 0,
4996 htlc_maximum_msat: OptionalField::Absent,
4998 fee_proportional_millionths: 0,
4999 excess_data: Vec::new()
5001 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
5003 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
5004 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5005 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5006 short_channel_id: 2,
5009 cltv_expiry_delta: (2 << 4) | 0,
5010 htlc_minimum_msat: 0,
5011 htlc_maximum_msat: OptionalField::Absent,
5013 fee_proportional_millionths: 0,
5014 excess_data: Vec::new()
5017 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
5018 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5019 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5020 short_channel_id: 1,
5023 cltv_expiry_delta: (1 << 4) | 0,
5024 htlc_minimum_msat: 100,
5025 htlc_maximum_msat: OptionalField::Absent,
5027 fee_proportional_millionths: 0,
5028 excess_data: Vec::new()
5030 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
5033 // Now ensure the route flows simply over nodes 1 and 4 to 6.
5034 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5035 assert_eq!(route.paths.len(), 1);
5036 assert_eq!(route.paths[0].len(), 3);
5038 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
5039 assert_eq!(route.paths[0][0].short_channel_id, 6);
5040 assert_eq!(route.paths[0][0].fee_msat, 100);
5041 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
5042 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
5043 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
5045 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
5046 assert_eq!(route.paths[0][1].short_channel_id, 5);
5047 assert_eq!(route.paths[0][1].fee_msat, 0);
5048 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
5049 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
5050 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
5052 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
5053 assert_eq!(route.paths[0][2].short_channel_id, 1);
5054 assert_eq!(route.paths[0][2].fee_msat, 10_000);
5055 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
5056 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
5057 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
5063 fn exact_fee_liquidity_limit() {
5064 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5065 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5066 // we calculated fees on a higher value, resulting in us ignoring such paths.
5067 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5068 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5069 let scorer = test_utils::TestScorer::with_penalty(0);
5070 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5071 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5072 let payment_params = PaymentParameters::from_node_id(nodes[2]);
5074 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5076 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5077 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5078 short_channel_id: 2,
5081 cltv_expiry_delta: 0,
5082 htlc_minimum_msat: 0,
5083 htlc_maximum_msat: OptionalField::Present(85_000),
5085 fee_proportional_millionths: 0,
5086 excess_data: Vec::new()
5089 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5090 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5091 short_channel_id: 12,
5094 cltv_expiry_delta: (4 << 4) | 1,
5095 htlc_minimum_msat: 0,
5096 htlc_maximum_msat: OptionalField::Present(270_000),
5098 fee_proportional_millionths: 1000000,
5099 excess_data: Vec::new()
5103 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5104 // 200% fee charged channel 13 in the 1-to-2 direction.
5105 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5106 assert_eq!(route.paths.len(), 1);
5107 assert_eq!(route.paths[0].len(), 2);
5109 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5110 assert_eq!(route.paths[0][0].short_channel_id, 12);
5111 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5112 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5113 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5114 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5116 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5117 assert_eq!(route.paths[0][1].short_channel_id, 13);
5118 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5119 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5120 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
5121 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5126 fn htlc_max_reduction_below_min() {
5127 // Test that if, while walking the graph, we reduce the value being sent to meet an
5128 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5129 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5130 // resulting in us thinking there is no possible path, even if other paths exist.
5131 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5132 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5133 let scorer = test_utils::TestScorer::with_penalty(0);
5134 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5135 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5136 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
5138 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5139 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5140 // then try to send 90_000.
5141 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5142 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5143 short_channel_id: 2,
5146 cltv_expiry_delta: 0,
5147 htlc_minimum_msat: 0,
5148 htlc_maximum_msat: OptionalField::Present(80_000),
5150 fee_proportional_millionths: 0,
5151 excess_data: Vec::new()
5153 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5154 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5155 short_channel_id: 4,
5158 cltv_expiry_delta: (4 << 4) | 1,
5159 htlc_minimum_msat: 90_000,
5160 htlc_maximum_msat: OptionalField::Absent,
5162 fee_proportional_millionths: 0,
5163 excess_data: Vec::new()
5167 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5168 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5169 // expensive) channels 12-13 path.
5170 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5171 assert_eq!(route.paths.len(), 1);
5172 assert_eq!(route.paths[0].len(), 2);
5174 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5175 assert_eq!(route.paths[0][0].short_channel_id, 12);
5176 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5177 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5178 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5179 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5181 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5182 assert_eq!(route.paths[0][1].short_channel_id, 13);
5183 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5184 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5185 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
5186 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5191 fn multiple_direct_first_hops() {
5192 // Previously we'd only ever considered one first hop path per counterparty.
5193 // However, as we don't restrict users to one channel per peer, we really need to support
5194 // looking at all first hop paths.
5195 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5196 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5197 // route over multiple channels with the same first hop.
5198 let secp_ctx = Secp256k1::new();
5199 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5200 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
5201 let logger = Arc::new(test_utils::TestLogger::new());
5202 let network_graph = NetworkGraph::new(genesis_hash, Arc::clone(&logger));
5203 let scorer = test_utils::TestScorer::with_penalty(0);
5204 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
5205 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5206 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5209 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5210 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
5211 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
5212 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5213 assert_eq!(route.paths.len(), 1);
5214 assert_eq!(route.paths[0].len(), 1);
5216 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5217 assert_eq!(route.paths[0][0].short_channel_id, 3);
5218 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5221 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5222 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5223 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5224 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5225 assert_eq!(route.paths.len(), 2);
5226 assert_eq!(route.paths[0].len(), 1);
5227 assert_eq!(route.paths[1].len(), 1);
5229 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5230 assert_eq!(route.paths[0][0].short_channel_id, 3);
5231 assert_eq!(route.paths[0][0].fee_msat, 50_000);
5233 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
5234 assert_eq!(route.paths[1][0].short_channel_id, 2);
5235 assert_eq!(route.paths[1][0].fee_msat, 50_000);
5239 // If we have a bunch of outbound channels to the same node, where most are not
5240 // sufficient to pay the full payment, but one is, we should default to just using the
5241 // one single channel that has sufficient balance, avoiding MPP.
5243 // If we have several options above the 3xpayment value threshold, we should pick the
5244 // smallest of them, avoiding further fragmenting our available outbound balance to
5246 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5247 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5248 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5249 &get_channel_details(Some(5), nodes[0], InitFeatures::known(), 50_000),
5250 &get_channel_details(Some(6), nodes[0], InitFeatures::known(), 300_000),
5251 &get_channel_details(Some(7), nodes[0], InitFeatures::known(), 50_000),
5252 &get_channel_details(Some(8), nodes[0], InitFeatures::known(), 50_000),
5253 &get_channel_details(Some(9), nodes[0], InitFeatures::known(), 50_000),
5254 &get_channel_details(Some(4), nodes[0], InitFeatures::known(), 1_000_000),
5255 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5256 assert_eq!(route.paths.len(), 1);
5257 assert_eq!(route.paths[0].len(), 1);
5259 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5260 assert_eq!(route.paths[0][0].short_channel_id, 6);
5261 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5266 fn prefers_shorter_route_with_higher_fees() {
5267 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5268 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5269 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5271 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5272 let scorer = test_utils::TestScorer::with_penalty(0);
5273 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5274 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5275 let route = get_route(
5276 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5277 Arc::clone(&logger), &scorer, &random_seed_bytes
5279 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5281 assert_eq!(route.get_total_fees(), 100);
5282 assert_eq!(route.get_total_amount(), 100);
5283 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5285 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5286 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5287 let scorer = test_utils::TestScorer::with_penalty(100);
5288 let route = get_route(
5289 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5290 Arc::clone(&logger), &scorer, &random_seed_bytes
5292 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5294 assert_eq!(route.get_total_fees(), 300);
5295 assert_eq!(route.get_total_amount(), 100);
5296 assert_eq!(path, vec![2, 4, 7, 10]);
5299 struct BadChannelScorer {
5300 short_channel_id: u64,
5304 impl Writeable for BadChannelScorer {
5305 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5307 impl Score for BadChannelScorer {
5308 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage) -> u64 {
5309 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5312 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5313 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5316 struct BadNodeScorer {
5321 impl Writeable for BadNodeScorer {
5322 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5325 impl Score for BadNodeScorer {
5326 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage) -> u64 {
5327 if *target == self.node_id { u64::max_value() } else { 0 }
5330 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5331 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5335 fn avoids_routing_through_bad_channels_and_nodes() {
5336 let (secp_ctx, network, _, _, logger) = build_graph();
5337 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5338 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5339 let network_graph = network.read_only();
5341 // A path to nodes[6] exists when no penalties are applied to any channel.
5342 let scorer = test_utils::TestScorer::with_penalty(0);
5343 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5344 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5345 let route = get_route(
5346 &our_id, &payment_params, &network_graph, None, 100, 42,
5347 Arc::clone(&logger), &scorer, &random_seed_bytes
5349 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5351 assert_eq!(route.get_total_fees(), 100);
5352 assert_eq!(route.get_total_amount(), 100);
5353 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5355 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5356 let scorer = BadChannelScorer { short_channel_id: 6 };
5357 let route = get_route(
5358 &our_id, &payment_params, &network_graph, None, 100, 42,
5359 Arc::clone(&logger), &scorer, &random_seed_bytes
5361 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5363 assert_eq!(route.get_total_fees(), 300);
5364 assert_eq!(route.get_total_amount(), 100);
5365 assert_eq!(path, vec![2, 4, 7, 10]);
5367 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5368 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5370 &our_id, &payment_params, &network_graph, None, 100, 42,
5371 Arc::clone(&logger), &scorer, &random_seed_bytes
5373 Err(LightningError { err, .. } ) => {
5374 assert_eq!(err, "Failed to find a path to the given destination");
5376 Ok(_) => panic!("Expected error"),
5381 fn total_fees_single_path() {
5385 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5386 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5387 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5390 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5391 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5392 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5395 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5396 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5397 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5400 payment_params: None,
5403 assert_eq!(route.get_total_fees(), 250);
5404 assert_eq!(route.get_total_amount(), 225);
5408 fn total_fees_multi_path() {
5412 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5413 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5414 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5417 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5418 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5419 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5423 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5424 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5425 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5428 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5429 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5430 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5433 payment_params: None,
5436 assert_eq!(route.get_total_fees(), 200);
5437 assert_eq!(route.get_total_amount(), 300);
5441 fn total_empty_route_no_panic() {
5442 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5443 // would both panic if the route was completely empty. We test to ensure they return 0
5444 // here, even though its somewhat nonsensical as a route.
5445 let route = Route { paths: Vec::new(), payment_params: None };
5447 assert_eq!(route.get_total_fees(), 0);
5448 assert_eq!(route.get_total_amount(), 0);
5452 fn limits_total_cltv_delta() {
5453 let (secp_ctx, network, _, _, logger) = build_graph();
5454 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5455 let network_graph = network.read_only();
5457 let scorer = test_utils::TestScorer::with_penalty(0);
5459 // Make sure that generally there is at least one route available
5460 let feasible_max_total_cltv_delta = 1008;
5461 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5462 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5463 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5464 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5465 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5466 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5467 assert_ne!(path.len(), 0);
5469 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5470 let fail_max_total_cltv_delta = 23;
5471 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5472 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5473 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5475 Err(LightningError { err, .. } ) => {
5476 assert_eq!(err, "Failed to find a path to the given destination");
5478 Ok(_) => panic!("Expected error"),
5483 fn limits_path_length() {
5484 let (secp_ctx, network, _, _, logger) = build_line_graph();
5485 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5486 let network_graph = network.read_only();
5488 let scorer = test_utils::TestScorer::with_penalty(0);
5489 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5490 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5492 // First check we can actually create a long route on this graph.
5493 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18]);
5494 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0,
5495 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5496 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5497 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5499 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5500 let fail_payment_params = PaymentParameters::from_node_id(nodes[19]);
5501 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0,
5502 Arc::clone(&logger), &scorer, &random_seed_bytes)
5504 Err(LightningError { err, .. } ) => {
5505 assert_eq!(err, "Failed to find a path to the given destination");
5507 Ok(_) => panic!("Expected error"),
5512 fn adds_and_limits_cltv_offset() {
5513 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5514 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5516 let scorer = test_utils::TestScorer::with_penalty(0);
5518 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5519 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5520 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5521 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5522 assert_eq!(route.paths.len(), 1);
5524 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5526 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5527 let mut route_default = route.clone();
5528 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5529 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5530 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5531 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5532 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5534 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5535 let mut route_limited = route.clone();
5536 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5537 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5538 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5539 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5540 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5544 fn adds_plausible_cltv_offset() {
5545 let (secp_ctx, network, _, _, logger) = build_graph();
5546 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5547 let network_graph = network.read_only();
5548 let network_nodes = network_graph.nodes();
5549 let network_channels = network_graph.channels();
5550 let scorer = test_utils::TestScorer::with_penalty(0);
5551 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5552 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5553 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5555 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5556 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5557 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5559 let mut path_plausibility = vec![];
5561 for p in route.paths {
5562 // 1. Select random observation point
5563 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5564 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5566 prng.process_in_place(&mut random_bytes);
5567 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5568 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5570 // 2. Calculate what CLTV expiry delta we would observe there
5571 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5573 // 3. Starting from the observation point, find candidate paths
5574 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5575 candidates.push_back((observation_point, vec![]));
5577 let mut found_plausible_candidate = false;
5579 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5580 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5581 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5582 found_plausible_candidate = true;
5583 break 'candidate_loop;
5587 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5588 for channel_id in &cur_node.channels {
5589 if let Some(channel_info) = network_channels.get(&channel_id) {
5590 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5591 if let Some(channel_update_info) = dir_info.direction() {
5592 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5593 if cur_path_cltv_deltas.iter().sum::<u32>()
5594 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5595 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5596 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5597 candidates.push_back((*next_id, new_path_cltv_deltas));
5606 path_plausibility.push(found_plausible_candidate);
5608 assert!(path_plausibility.iter().all(|x| *x));
5612 fn builds_correct_path_from_hops() {
5613 let (secp_ctx, network, _, _, logger) = build_graph();
5614 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5615 let network_graph = network.read_only();
5617 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5618 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5620 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5621 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5622 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5623 &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
5624 let route_hop_pubkeys = route.paths[0].iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5625 assert_eq!(hops.len(), route.paths[0].len());
5626 for (idx, hop_pubkey) in hops.iter().enumerate() {
5627 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5631 #[cfg(not(feature = "no-std"))]
5632 pub(super) fn random_init_seed() -> u64 {
5633 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5634 use core::hash::{BuildHasher, Hasher};
5635 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5636 println!("Using seed of {}", seed);
5639 #[cfg(not(feature = "no-std"))]
5640 use util::ser::ReadableArgs;
5643 #[cfg(not(feature = "no-std"))]
5644 fn generate_routes() {
5645 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5647 let mut d = match super::test_utils::get_route_file() {
5654 let logger = test_utils::TestLogger::new();
5655 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5656 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5657 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5659 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5660 let mut seed = random_init_seed() as usize;
5661 let nodes = graph.read_only().nodes().clone();
5662 'load_endpoints: for _ in 0..10 {
5664 seed = seed.overflowing_mul(0xdeadbeef).0;
5665 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5666 seed = seed.overflowing_mul(0xdeadbeef).0;
5667 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5668 let payment_params = PaymentParameters::from_node_id(dst);
5669 let amt = seed as u64 % 200_000_000;
5670 let params = ProbabilisticScoringParameters::default();
5671 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5672 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5673 continue 'load_endpoints;
5680 #[cfg(not(feature = "no-std"))]
5681 fn generate_routes_mpp() {
5682 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5684 let mut d = match super::test_utils::get_route_file() {
5691 let logger = test_utils::TestLogger::new();
5692 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5693 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5694 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5696 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5697 let mut seed = random_init_seed() as usize;
5698 let nodes = graph.read_only().nodes().clone();
5699 'load_endpoints: for _ in 0..10 {
5701 seed = seed.overflowing_mul(0xdeadbeef).0;
5702 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5703 seed = seed.overflowing_mul(0xdeadbeef).0;
5704 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5705 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5706 let amt = seed as u64 % 200_000_000;
5707 let params = ProbabilisticScoringParameters::default();
5708 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5709 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5710 continue 'load_endpoints;
5717 #[cfg(all(test, not(feature = "no-std")))]
5718 pub(crate) mod test_utils {
5720 /// Tries to open a network graph file, or panics with a URL to fetch it.
5721 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5722 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5723 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5724 .or_else(|_| { // Fall back to guessing based on the binary location
5725 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5726 let mut path = std::env::current_exe().unwrap();
5727 path.pop(); // lightning-...
5729 path.pop(); // debug
5730 path.pop(); // target
5731 path.push("lightning");
5732 path.push("net_graph-2021-05-31.bin");
5733 eprintln!("{}", path.to_str().unwrap());
5736 .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");
5737 #[cfg(require_route_graph_test)]
5738 return Ok(res.unwrap());
5739 #[cfg(not(require_route_graph_test))]
5744 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5747 use bitcoin::hashes::Hash;
5748 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5749 use chain::transaction::OutPoint;
5750 use chain::keysinterface::{KeysManager,KeysInterface};
5751 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5752 use ln::features::{InitFeatures, InvoiceFeatures};
5753 use routing::gossip::NetworkGraph;
5754 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters};
5755 use util::logger::{Logger, Record};
5756 use util::ser::ReadableArgs;
5760 struct DummyLogger {}
5761 impl Logger for DummyLogger {
5762 fn log(&self, _record: &Record) {}
5765 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
5766 let mut d = test_utils::get_route_file().unwrap();
5767 NetworkGraph::read(&mut d, logger).unwrap()
5770 fn payer_pubkey() -> PublicKey {
5771 let secp_ctx = Secp256k1::new();
5772 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5776 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5778 channel_id: [0; 32],
5779 counterparty: ChannelCounterparty {
5780 features: InitFeatures::known(),
5782 unspendable_punishment_reserve: 0,
5783 forwarding_info: None,
5784 outbound_htlc_minimum_msat: None,
5785 outbound_htlc_maximum_msat: None,
5787 funding_txo: Some(OutPoint {
5788 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5791 short_channel_id: Some(1),
5792 inbound_scid_alias: None,
5793 outbound_scid_alias: None,
5794 channel_value_satoshis: 10_000_000,
5796 balance_msat: 10_000_000,
5797 outbound_capacity_msat: 10_000_000,
5798 next_outbound_htlc_limit_msat: 10_000_000,
5799 inbound_capacity_msat: 0,
5800 unspendable_punishment_reserve: None,
5801 confirmations_required: None,
5802 force_close_spend_delay: None,
5804 is_channel_ready: true,
5807 inbound_htlc_minimum_msat: None,
5808 inbound_htlc_maximum_msat: None,
5813 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5814 let logger = DummyLogger {};
5815 let network_graph = read_network_graph(&logger);
5816 let scorer = FixedPenaltyScorer::with_penalty(0);
5817 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5821 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5822 let logger = DummyLogger {};
5823 let network_graph = read_network_graph(&logger);
5824 let scorer = FixedPenaltyScorer::with_penalty(0);
5825 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5829 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5830 let logger = DummyLogger {};
5831 let network_graph = read_network_graph(&logger);
5832 let params = ProbabilisticScoringParameters::default();
5833 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5834 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5838 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5839 let logger = DummyLogger {};
5840 let network_graph = read_network_graph(&logger);
5841 let params = ProbabilisticScoringParameters::default();
5842 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5843 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5846 fn generate_routes<S: Score>(
5847 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S,
5848 features: InvoiceFeatures
5850 let nodes = graph.read_only().nodes().clone();
5851 let payer = payer_pubkey();
5852 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5853 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5855 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5856 let mut routes = Vec::new();
5857 let mut route_endpoints = Vec::new();
5858 let mut seed: usize = 0xdeadbeef;
5859 'load_endpoints: for _ in 0..150 {
5862 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5864 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5865 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5866 let first_hop = first_hop(src);
5867 let amt = seed as u64 % 1_000_000;
5868 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5870 route_endpoints.push((first_hop, params, amt));
5871 continue 'load_endpoints;
5876 // ...and seed the scorer with success and failure data...
5877 for route in routes {
5878 let amount = route.get_total_amount();
5879 if amount < 250_000 {
5880 for path in route.paths {
5881 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5883 } else if amount > 750_000 {
5884 for path in route.paths {
5885 let short_channel_id = path[path.len() / 2].short_channel_id;
5886 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5891 // Because we've changed channel scores, its possible we'll take different routes to the
5892 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5893 // requires a too-high CLTV delta.
5894 route_endpoints.retain(|(first_hop, params, amt)| {
5895 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5897 route_endpoints.truncate(100);
5898 assert_eq!(route_endpoints.len(), 100);
5900 // ...then benchmark finding paths between the nodes we learned.
5903 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5904 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());