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, NetworkGraph, 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_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_PATH_COUNT`].
227 pub max_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_path_count, (default_value, DEFAULT_MAX_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_path_count: DEFAULT_MAX_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.
287 /// (C-not exported) since bindings don't support move semantics
288 pub fn with_max_path_count(self, max_path_count: u8) -> Self {
289 Self { max_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, GL: Deref, S: Score>(
694 our_node_pubkey: &PublicKey, route_params: &RouteParameters,
695 network_graph: &NetworkGraph<GL>, first_hops: Option<&[&ChannelDetails]>, logger: L,
696 scorer: &S, random_seed_bytes: &[u8; 32]
697 ) -> Result<Route, LightningError>
698 where L::Target: Logger, GL::Target: Logger {
699 let graph_lock = network_graph.read_only();
700 let mut route = get_route(our_node_pubkey, &route_params.payment_params, &graph_lock, first_hops,
701 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, scorer,
703 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
707 pub(crate) fn get_route<L: Deref, S: Score>(
708 our_node_pubkey: &PublicKey, payment_params: &PaymentParameters, network_graph: &ReadOnlyNetworkGraph,
709 first_hops: Option<&[&ChannelDetails]>, final_value_msat: u64, final_cltv_expiry_delta: u32,
710 logger: L, scorer: &S, random_seed_bytes: &[u8; 32]
711 ) -> Result<Route, LightningError>
712 where L::Target: Logger {
713 let payee_node_id = NodeId::from_pubkey(&payment_params.payee_pubkey);
714 let our_node_id = NodeId::from_pubkey(&our_node_pubkey);
716 if payee_node_id == our_node_id {
717 return Err(LightningError{err: "Cannot generate a route to ourselves".to_owned(), action: ErrorAction::IgnoreError});
720 if final_value_msat > MAX_VALUE_MSAT {
721 return Err(LightningError{err: "Cannot generate a route of more value than all existing satoshis".to_owned(), action: ErrorAction::IgnoreError});
724 if final_value_msat == 0 {
725 return Err(LightningError{err: "Cannot send a payment of 0 msat".to_owned(), action: ErrorAction::IgnoreError});
728 for route in payment_params.route_hints.iter() {
729 for hop in &route.0 {
730 if hop.src_node_id == payment_params.payee_pubkey {
731 return Err(LightningError{err: "Route hint cannot have the payee as the source.".to_owned(), action: ErrorAction::IgnoreError});
735 if payment_params.max_total_cltv_expiry_delta <= final_cltv_expiry_delta {
736 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});
739 // The general routing idea is the following:
740 // 1. Fill first/last hops communicated by the caller.
741 // 2. Attempt to construct a path from payer to payee for transferring
742 // any ~sufficient (described later) value.
743 // If succeed, remember which channels were used and how much liquidity they have available,
744 // so that future paths don't rely on the same liquidity.
745 // 3. Proceed to the next step if:
746 // - we hit the recommended target value;
747 // - OR if we could not construct a new path. Any next attempt will fail too.
748 // Otherwise, repeat step 2.
749 // 4. See if we managed to collect paths which aggregately are able to transfer target value
750 // (not recommended value).
751 // 5. If yes, proceed. If not, fail routing.
752 // 6. Randomly combine paths into routes having enough to fulfill the payment. (TODO: knapsack)
753 // 7. Of all the found paths, select only those with the lowest total fee.
754 // 8. The last path in every selected route is likely to be more than we need.
755 // Reduce its value-to-transfer and recompute fees.
756 // 9. Choose the best route by the lowest total fee.
758 // As for the actual search algorithm,
759 // we do a payee-to-payer pseudo-Dijkstra's sorting by each node's distance from the payee
760 // plus the minimum per-HTLC fee to get from it to another node (aka "shitty pseudo-A*").
762 // We are not a faithful Dijkstra's implementation because we can change values which impact
763 // earlier nodes while processing later nodes. Specifically, if we reach a channel with a lower
764 // liquidity limit (via htlc_maximum_msat, on-chain capacity or assumed liquidity limits) than
765 // the value we are currently attempting to send over a path, we simply reduce the value being
766 // sent along the path for any hops after that channel. This may imply that later fees (which
767 // we've already tabulated) are lower because a smaller value is passing through the channels
768 // (and the proportional fee is thus lower). There isn't a trivial way to recalculate the
769 // channels which were selected earlier (and which may still be used for other paths without a
770 // lower liquidity limit), so we simply accept that some liquidity-limited paths may be
773 // One potentially problematic case for this algorithm would be if there are many
774 // liquidity-limited paths which are liquidity-limited near the destination (ie early in our
775 // graph walking), we may never find a path which is not liquidity-limited and has lower
776 // proportional fee (and only lower absolute fee when considering the ultimate value sent).
777 // Because we only consider paths with at least 5% of the total value being sent, the damage
778 // from such a case should be limited, however this could be further reduced in the future by
779 // calculating fees on the amount we wish to route over a path, ie ignoring the liquidity
780 // limits for the purposes of fee calculation.
782 // Alternatively, we could store more detailed path information in the heap (targets, below)
783 // and index the best-path map (dist, below) by node *and* HTLC limits, however that would blow
784 // up the runtime significantly both algorithmically (as we'd traverse nodes multiple times)
785 // and practically (as we would need to store dynamically-allocated path information in heap
786 // objects, increasing malloc traffic and indirect memory access significantly). Further, the
787 // results of such an algorithm would likely be biased towards lower-value paths.
789 // Further, we could return to a faithful Dijkstra's algorithm by rejecting paths with limits
790 // outside of our current search value, running a path search more times to gather candidate
791 // paths at different values. While this may be acceptable, further path searches may increase
792 // runtime for little gain. Specifically, the current algorithm rather efficiently explores the
793 // graph for candidate paths, calculating the maximum value which can realistically be sent at
794 // the same time, remaining generic across different payment values.
796 // TODO: There are a few tweaks we could do, including possibly pre-calculating more stuff
797 // to use as the A* heuristic beyond just the cost to get one node further than the current
800 let network_channels = network_graph.channels();
801 let network_nodes = network_graph.nodes();
803 if payment_params.max_path_count == 0 {
804 return Err(LightningError{err: "Can't find a route with no paths allowed.".to_owned(), action: ErrorAction::IgnoreError});
807 // Allow MPP only if we have a features set from somewhere that indicates the payee supports
808 // it. If the payee supports it they're supposed to include it in the invoice, so that should
810 let allow_mpp = if payment_params.max_path_count == 1 {
812 } else if let Some(features) = &payment_params.features {
813 features.supports_basic_mpp()
814 } else if let Some(node) = network_nodes.get(&payee_node_id) {
815 if let Some(node_info) = node.announcement_info.as_ref() {
816 node_info.features.supports_basic_mpp()
820 log_trace!(logger, "Searching for a route from payer {} to payee {} {} MPP and {} first hops {}overriding the network graph", our_node_pubkey,
821 payment_params.payee_pubkey, if allow_mpp { "with" } else { "without" },
822 first_hops.map(|hops| hops.len()).unwrap_or(0), if first_hops.is_some() { "" } else { "not " });
825 // Prepare the data we'll use for payee-to-payer search by
826 // inserting first hops suggested by the caller as targets.
827 // Our search will then attempt to reach them while traversing from the payee node.
828 let mut first_hop_targets: HashMap<_, Vec<&ChannelDetails>> =
829 HashMap::with_capacity(if first_hops.is_some() { first_hops.as_ref().unwrap().len() } else { 0 });
830 if let Some(hops) = first_hops {
832 if chan.get_outbound_payment_scid().is_none() {
833 panic!("first_hops should be filled in with usable channels, not pending ones");
835 if chan.counterparty.node_id == *our_node_pubkey {
836 return Err(LightningError{err: "First hop cannot have our_node_pubkey as a destination.".to_owned(), action: ErrorAction::IgnoreError});
839 .entry(NodeId::from_pubkey(&chan.counterparty.node_id))
840 .or_insert(Vec::new())
843 if first_hop_targets.is_empty() {
844 return Err(LightningError{err: "Cannot route when there are no outbound routes away from us".to_owned(), action: ErrorAction::IgnoreError});
848 // The main heap containing all candidate next-hops sorted by their score (max(A* fee,
849 // htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
850 // adding duplicate entries when we find a better path to a given node.
851 let mut targets: BinaryHeap<RouteGraphNode> = BinaryHeap::new();
853 // Map from node_id to information about the best current path to that node, including feerate
855 let mut dist: HashMap<NodeId, PathBuildingHop> = HashMap::with_capacity(network_nodes.len());
857 // During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
858 // indicating that we may wish to try again with a higher value, potentially paying to meet an
859 // htlc_minimum with extra fees while still finding a cheaper path.
860 let mut hit_minimum_limit;
862 // When arranging a route, we select multiple paths so that we can make a multi-path payment.
863 // We start with a path_value of the exact amount we want, and if that generates a route we may
864 // return it immediately. Otherwise, we don't stop searching for paths until we have 3x the
865 // amount we want in total across paths, selecting the best subset at the end.
866 const ROUTE_CAPACITY_PROVISION_FACTOR: u64 = 3;
867 let recommended_value_msat = final_value_msat * ROUTE_CAPACITY_PROVISION_FACTOR as u64;
868 let mut path_value_msat = final_value_msat;
870 // Routing Fragmentation Mitigation heuristic:
872 // Routing fragmentation across many payment paths increases the overall routing
873 // fees as you have irreducible routing fees per-link used (`fee_base_msat`).
874 // Taking too many smaller paths also increases the chance of payment failure.
875 // Thus to avoid this effect, we require from our collected links to provide
876 // at least a minimal contribution to the recommended value yet-to-be-fulfilled.
877 // This requirement is currently set to be 1/max_path_count of the payment
878 // value to ensure we only ever return routes that do not violate this limit.
879 let minimal_value_contribution_msat: u64 = if allow_mpp {
880 (final_value_msat + (payment_params.max_path_count as u64 - 1)) / payment_params.max_path_count as u64
885 // Keep track of how much liquidity has been used in selected channels. Used to determine
886 // if the channel can be used by additional MPP paths or to inform path finding decisions. It is
887 // aware of direction *only* to ensure that the correct htlc_maximum_msat value is used. Hence,
888 // liquidity used in one direction will not offset any used in the opposite direction.
889 let mut used_channel_liquidities: HashMap<(u64, bool), u64> =
890 HashMap::with_capacity(network_nodes.len());
892 // Keeping track of how much value we already collected across other paths. Helps to decide
893 // when we want to stop looking for new paths.
894 let mut already_collected_value_msat = 0;
896 for (_, channels) in first_hop_targets.iter_mut() {
897 // Sort the first_hops channels to the same node(s) in priority order of which channel we'd
900 // First, if channels are below `recommended_value_msat`, sort them in descending order,
901 // preferring larger channels to avoid splitting the payment into more MPP parts than is
904 // Second, because simply always sorting in descending order would always use our largest
905 // available outbound capacity, needlessly fragmenting our available channel capacities,
906 // sort channels above `recommended_value_msat` in ascending order, preferring channels
907 // which have enough, but not too much, capacity for the payment.
908 channels.sort_unstable_by(|chan_a, chan_b| {
909 if chan_b.next_outbound_htlc_limit_msat < recommended_value_msat || chan_a.next_outbound_htlc_limit_msat < recommended_value_msat {
910 // Sort in descending order
911 chan_b.next_outbound_htlc_limit_msat.cmp(&chan_a.next_outbound_htlc_limit_msat)
913 // Sort in ascending order
914 chan_a.next_outbound_htlc_limit_msat.cmp(&chan_b.next_outbound_htlc_limit_msat)
919 log_trace!(logger, "Building path from {} (payee) to {} (us/payer) for value {} msat.", payment_params.payee_pubkey, our_node_pubkey, final_value_msat);
921 macro_rules! add_entry {
922 // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
923 // $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
924 // since that value has to be transferred over this channel.
925 // Returns whether this channel caused an update to `targets`.
926 ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
927 $next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
928 $next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
929 // We "return" whether we updated the path at the end, via this:
930 let mut did_add_update_path_to_src_node = false;
931 // Channels to self should not be used. This is more of belt-and-suspenders, because in
932 // practice these cases should be caught earlier:
933 // - for regular channels at channel announcement (TODO)
934 // - for first and last hops early in get_route
935 if $src_node_id != $dest_node_id {
936 let short_channel_id = $candidate.short_channel_id();
937 let htlc_maximum_msat = $candidate.htlc_maximum_msat();
939 // It is tricky to subtract $next_hops_fee_msat from available liquidity here.
940 // It may be misleading because we might later choose to reduce the value transferred
941 // over these channels, and the channel which was insufficient might become sufficient.
942 // Worst case: we drop a good channel here because it can't cover the high following
943 // fees caused by one expensive channel, but then this channel could have been used
944 // if the amount being transferred over this path is lower.
945 // We do this for now, but this is a subject for removal.
946 if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
947 let used_liquidity_msat = used_channel_liquidities
948 .get(&(short_channel_id, $src_node_id < $dest_node_id))
949 .map_or(0, |used_liquidity_msat| {
950 available_value_contribution_msat = available_value_contribution_msat
951 .saturating_sub(*used_liquidity_msat);
955 // Verify the liquidity offered by this channel complies to the minimal contribution.
956 let contributes_sufficient_value = available_value_contribution_msat >= minimal_value_contribution_msat;
957 // Do not consider candidate hops that would exceed the maximum path length.
958 let path_length_to_node = $next_hops_path_length + 1;
959 let doesnt_exceed_max_path_length = path_length_to_node <= MAX_PATH_LENGTH_ESTIMATE;
961 // Do not consider candidates that exceed the maximum total cltv expiry limit.
962 // In order to already account for some of the privacy enhancing random CLTV
963 // expiry delta offset we add on top later, we subtract a rough estimate
964 // (2*MEDIAN_HOP_CLTV_EXPIRY_DELTA) here.
965 let max_total_cltv_expiry_delta = (payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta)
966 .checked_sub(2*MEDIAN_HOP_CLTV_EXPIRY_DELTA)
967 .unwrap_or(payment_params.max_total_cltv_expiry_delta - final_cltv_expiry_delta);
968 let hop_total_cltv_delta = ($next_hops_cltv_delta as u32)
969 .saturating_add($candidate.cltv_expiry_delta());
970 let doesnt_exceed_cltv_delta_limit = hop_total_cltv_delta <= max_total_cltv_expiry_delta;
972 let value_contribution_msat = cmp::min(available_value_contribution_msat, $next_hops_value_contribution);
973 // Includes paying fees for the use of the following channels.
974 let amount_to_transfer_over_msat: u64 = match value_contribution_msat.checked_add($next_hops_fee_msat) {
975 Some(result) => result,
976 // Can't overflow due to how the values were computed right above.
977 None => unreachable!(),
979 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
980 let over_path_minimum_msat = amount_to_transfer_over_msat >= $candidate.htlc_minimum_msat() &&
981 amount_to_transfer_over_msat >= $next_hops_path_htlc_minimum_msat;
983 #[allow(unused_comparisons)] // $next_hops_path_htlc_minimum_msat is 0 in some calls so rustc complains
984 let may_overpay_to_meet_path_minimum_msat =
985 ((amount_to_transfer_over_msat < $candidate.htlc_minimum_msat() &&
986 recommended_value_msat > $candidate.htlc_minimum_msat()) ||
987 (amount_to_transfer_over_msat < $next_hops_path_htlc_minimum_msat &&
988 recommended_value_msat > $next_hops_path_htlc_minimum_msat));
990 // If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
991 // bother considering this channel. If retrying with recommended_value_msat may
992 // allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
993 // around again with a higher amount.
994 if contributes_sufficient_value && doesnt_exceed_max_path_length &&
995 doesnt_exceed_cltv_delta_limit && may_overpay_to_meet_path_minimum_msat {
996 hit_minimum_limit = true;
997 } else if contributes_sufficient_value && doesnt_exceed_max_path_length &&
998 doesnt_exceed_cltv_delta_limit && over_path_minimum_msat {
999 // Note that low contribution here (limited by available_liquidity_msat)
1000 // might violate htlc_minimum_msat on the hops which are next along the
1001 // payment path (upstream to the payee). To avoid that, we recompute
1002 // path fees knowing the final path contribution after constructing it.
1003 let path_htlc_minimum_msat = compute_fees($next_hops_path_htlc_minimum_msat, $candidate.fees())
1004 .and_then(|fee_msat| fee_msat.checked_add($next_hops_path_htlc_minimum_msat))
1005 .map(|fee_msat| cmp::max(fee_msat, $candidate.htlc_minimum_msat()))
1006 .unwrap_or_else(|| u64::max_value());
1007 let hm_entry = dist.entry($src_node_id);
1008 let old_entry = hm_entry.or_insert_with(|| {
1009 // If there was previously no known way to access the source node
1010 // (recall it goes payee-to-payer) of short_channel_id, first add a
1011 // semi-dummy record just to compute the fees to reach the source node.
1012 // This will affect our decision on selecting short_channel_id
1013 // as a way to reach the $dest_node_id.
1014 let mut fee_base_msat = 0;
1015 let mut fee_proportional_millionths = 0;
1016 if let Some(Some(fees)) = network_nodes.get(&$src_node_id).map(|node| node.lowest_inbound_channel_fees) {
1017 fee_base_msat = fees.base_msat;
1018 fee_proportional_millionths = fees.proportional_millionths;
1021 node_id: $dest_node_id.clone(),
1022 candidate: $candidate.clone(),
1024 src_lowest_inbound_fees: RoutingFees {
1025 base_msat: fee_base_msat,
1026 proportional_millionths: fee_proportional_millionths,
1028 next_hops_fee_msat: u64::max_value(),
1029 hop_use_fee_msat: u64::max_value(),
1030 total_fee_msat: u64::max_value(),
1031 path_htlc_minimum_msat,
1032 path_penalty_msat: u64::max_value(),
1033 was_processed: false,
1034 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1035 value_contribution_msat,
1039 #[allow(unused_mut)] // We only use the mut in cfg(test)
1040 let mut should_process = !old_entry.was_processed;
1041 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1043 // In test/fuzzing builds, we do extra checks to make sure the skipping
1044 // of already-seen nodes only happens in cases we expect (see below).
1045 if !should_process { should_process = true; }
1049 let mut hop_use_fee_msat = 0;
1050 let mut total_fee_msat = $next_hops_fee_msat;
1052 // Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
1053 // will have the same effective-fee
1054 if $src_node_id != our_node_id {
1055 match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
1056 // max_value means we'll always fail
1057 // the old_entry.total_fee_msat > total_fee_msat check
1058 None => total_fee_msat = u64::max_value(),
1060 hop_use_fee_msat = fee_msat;
1061 total_fee_msat += hop_use_fee_msat;
1062 // When calculating the lowest inbound fees to a node, we
1063 // calculate fees here not based on the actual value we think
1064 // will flow over this channel, but on the minimum value that
1065 // we'll accept flowing over it. The minimum accepted value
1066 // is a constant through each path collection run, ensuring
1067 // consistent basis. Otherwise we may later find a
1068 // different path to the source node that is more expensive,
1069 // but which we consider to be cheaper because we are capacity
1070 // constrained and the relative fee becomes lower.
1071 match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
1072 .map(|a| a.checked_add(total_fee_msat)) {
1077 total_fee_msat = u64::max_value();
1084 let channel_usage = ChannelUsage {
1085 amount_msat: amount_to_transfer_over_msat,
1086 inflight_htlc_msat: used_liquidity_msat,
1087 effective_capacity: $candidate.effective_capacity(),
1089 let channel_penalty_msat = scorer.channel_penalty_msat(
1090 short_channel_id, &$src_node_id, &$dest_node_id, channel_usage
1092 let path_penalty_msat = $next_hops_path_penalty_msat
1093 .saturating_add(channel_penalty_msat);
1094 let new_graph_node = RouteGraphNode {
1095 node_id: $src_node_id,
1096 lowest_fee_to_peer_through_node: total_fee_msat,
1097 lowest_fee_to_node: $next_hops_fee_msat as u64 + hop_use_fee_msat,
1098 total_cltv_delta: hop_total_cltv_delta,
1099 value_contribution_msat: value_contribution_msat,
1100 path_htlc_minimum_msat,
1102 path_length_to_node,
1105 // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
1106 // if this way is cheaper than the already known
1107 // (considering the cost to "reach" this channel from the route destination,
1108 // the cost of using this channel,
1109 // and the cost of routing to the source node of this channel).
1110 // Also, consider that htlc_minimum_msat_difference, because we might end up
1111 // paying it. Consider the following exploit:
1112 // we use 2 paths to transfer 1.5 BTC. One of them is 0-fee normal 1 BTC path,
1113 // and for the other one we picked a 1sat-fee path with htlc_minimum_msat of
1114 // 1 BTC. Now, since the latter is more expensive, we gonna try to cut it
1115 // by 0.5 BTC, but then match htlc_minimum_msat by paying a fee of 0.5 BTC
1117 // Ideally the scoring could be smarter (e.g. 0.5*htlc_minimum_msat here),
1118 // but it may require additional tracking - we don't want to double-count
1119 // the fees included in $next_hops_path_htlc_minimum_msat, but also
1120 // can't use something that may decrease on future hops.
1121 let old_cost = cmp::max(old_entry.total_fee_msat, old_entry.path_htlc_minimum_msat)
1122 .saturating_add(old_entry.path_penalty_msat);
1123 let new_cost = cmp::max(total_fee_msat, path_htlc_minimum_msat)
1124 .saturating_add(path_penalty_msat);
1126 if !old_entry.was_processed && new_cost < old_cost {
1127 targets.push(new_graph_node);
1128 old_entry.next_hops_fee_msat = $next_hops_fee_msat;
1129 old_entry.hop_use_fee_msat = hop_use_fee_msat;
1130 old_entry.total_fee_msat = total_fee_msat;
1131 old_entry.node_id = $dest_node_id.clone();
1132 old_entry.candidate = $candidate.clone();
1133 old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
1134 old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
1135 old_entry.path_penalty_msat = path_penalty_msat;
1136 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1138 old_entry.value_contribution_msat = value_contribution_msat;
1140 did_add_update_path_to_src_node = true;
1141 } else if old_entry.was_processed && new_cost < old_cost {
1142 #[cfg(all(not(feature = "_bench_unstable"), any(test, fuzzing)))]
1144 // If we're skipping processing a node which was previously
1145 // processed even though we found another path to it with a
1146 // cheaper fee, check that it was because the second path we
1147 // found (which we are processing now) has a lower value
1148 // contribution due to an HTLC minimum limit.
1150 // e.g. take a graph with two paths from node 1 to node 2, one
1151 // through channel A, and one through channel B. Channel A and
1152 // B are both in the to-process heap, with their scores set by
1153 // a higher htlc_minimum than fee.
1154 // Channel A is processed first, and the channels onwards from
1155 // node 1 are added to the to-process heap. Thereafter, we pop
1156 // Channel B off of the heap, note that it has a much more
1157 // restrictive htlc_maximum_msat, and recalculate the fees for
1158 // all of node 1's channels using the new, reduced, amount.
1160 // This would be bogus - we'd be selecting a higher-fee path
1161 // with a lower htlc_maximum_msat instead of the one we'd
1162 // already decided to use.
1163 debug_assert!(path_htlc_minimum_msat < old_entry.path_htlc_minimum_msat);
1165 value_contribution_msat + path_penalty_msat <
1166 old_entry.value_contribution_msat + old_entry.path_penalty_msat
1174 did_add_update_path_to_src_node
1178 let default_node_features = default_node_features();
1180 // Find ways (channels with destination) to reach a given node and store them
1181 // in the corresponding data structures (routing graph etc).
1182 // $fee_to_target_msat represents how much it costs to reach to this node from the payee,
1183 // meaning how much will be paid in fees after this node (to the best of our knowledge).
1184 // This data can later be helpful to optimize routing (pay lower fees).
1185 macro_rules! add_entries_to_cheapest_to_target_node {
1186 ( $node: expr, $node_id: expr, $fee_to_target_msat: expr, $next_hops_value_contribution: expr,
1187 $next_hops_path_htlc_minimum_msat: expr, $next_hops_path_penalty_msat: expr,
1188 $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => {
1189 let skip_node = if let Some(elem) = dist.get_mut(&$node_id) {
1190 let was_processed = elem.was_processed;
1191 elem.was_processed = true;
1194 // Entries are added to dist in add_entry!() when there is a channel from a node.
1195 // Because there are no channels from payee, it will not have a dist entry at this point.
1196 // If we're processing any other node, it is always be the result of a channel from it.
1197 assert_eq!($node_id, payee_node_id);
1202 if let Some(first_channels) = first_hop_targets.get(&$node_id) {
1203 for details in first_channels {
1204 let candidate = CandidateRouteHop::FirstHop { details };
1205 add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
1206 $next_hops_value_contribution,
1207 $next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
1208 $next_hops_cltv_delta, $next_hops_path_length);
1212 let features = if let Some(node_info) = $node.announcement_info.as_ref() {
1215 &default_node_features
1218 if !features.requires_unknown_bits() {
1219 for chan_id in $node.channels.iter() {
1220 let chan = network_channels.get(chan_id).unwrap();
1221 if !chan.features.requires_unknown_bits() {
1222 let (directed_channel, source) =
1223 chan.as_directed_to(&$node_id).expect("inconsistent NetworkGraph");
1224 if first_hops.is_none() || *source != our_node_id {
1225 if let Some(direction) = directed_channel.direction() {
1226 if direction.enabled {
1227 let candidate = CandidateRouteHop::PublicHop {
1228 info: directed_channel.with_update().unwrap(),
1229 short_channel_id: *chan_id,
1231 add_entry!(candidate, *source, $node_id,
1232 $fee_to_target_msat,
1233 $next_hops_value_contribution,
1234 $next_hops_path_htlc_minimum_msat,
1235 $next_hops_path_penalty_msat,
1236 $next_hops_cltv_delta, $next_hops_path_length);
1247 let mut payment_paths = Vec::<PaymentPath>::new();
1249 // TODO: diversify by nodes (so that all paths aren't doomed if one node is offline).
1250 'paths_collection: loop {
1251 // For every new path, start from scratch, except for used_channel_liquidities, which
1252 // helps to avoid reusing previously selected paths in future iterations.
1255 hit_minimum_limit = false;
1257 // If first hop is a private channel and the only way to reach the payee, this is the only
1258 // place where it could be added.
1259 if let Some(first_channels) = first_hop_targets.get(&payee_node_id) {
1260 for details in first_channels {
1261 let candidate = CandidateRouteHop::FirstHop { details };
1262 let added = add_entry!(candidate, our_node_id, payee_node_id, 0, path_value_msat,
1264 log_trace!(logger, "{} direct route to payee via SCID {}",
1265 if added { "Added" } else { "Skipped" }, candidate.short_channel_id());
1269 // Add the payee as a target, so that the payee-to-payer
1270 // search algorithm knows what to start with.
1271 match network_nodes.get(&payee_node_id) {
1272 // The payee is not in our network graph, so nothing to add here.
1273 // There is still a chance of reaching them via last_hops though,
1274 // so don't yet fail the payment here.
1275 // If not, targets.pop() will not even let us enter the loop in step 2.
1278 add_entries_to_cheapest_to_target_node!(node, payee_node_id, 0, path_value_msat, 0, 0u64, 0, 0);
1283 // If a caller provided us with last hops, add them to routing targets. Since this happens
1284 // earlier than general path finding, they will be somewhat prioritized, although currently
1285 // it matters only if the fees are exactly the same.
1286 for route in payment_params.route_hints.iter().filter(|route| !route.0.is_empty()) {
1287 let first_hop_in_route = &(route.0)[0];
1288 let have_hop_src_in_graph =
1289 // Only add the hops in this route to our candidate set if either
1290 // we have a direct channel to the first hop or the first hop is
1291 // in the regular network graph.
1292 first_hop_targets.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some() ||
1293 network_nodes.get(&NodeId::from_pubkey(&first_hop_in_route.src_node_id)).is_some();
1294 if have_hop_src_in_graph {
1295 // We start building the path from reverse, i.e., from payee
1296 // to the first RouteHintHop in the path.
1297 let hop_iter = route.0.iter().rev();
1298 let prev_hop_iter = core::iter::once(&payment_params.payee_pubkey).chain(
1299 route.0.iter().skip(1).rev().map(|hop| &hop.src_node_id));
1300 let mut hop_used = true;
1301 let mut aggregate_next_hops_fee_msat: u64 = 0;
1302 let mut aggregate_next_hops_path_htlc_minimum_msat: u64 = 0;
1303 let mut aggregate_next_hops_path_penalty_msat: u64 = 0;
1304 let mut aggregate_next_hops_cltv_delta: u32 = 0;
1305 let mut aggregate_next_hops_path_length: u8 = 0;
1307 for (idx, (hop, prev_hop_id)) in hop_iter.zip(prev_hop_iter).enumerate() {
1308 let source = NodeId::from_pubkey(&hop.src_node_id);
1309 let target = NodeId::from_pubkey(&prev_hop_id);
1310 let candidate = network_channels
1311 .get(&hop.short_channel_id)
1312 .and_then(|channel| channel.as_directed_to(&target))
1313 .and_then(|(channel, _)| channel.with_update())
1314 .map(|info| CandidateRouteHop::PublicHop {
1316 short_channel_id: hop.short_channel_id,
1318 .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
1320 if !add_entry!(candidate, source, target, aggregate_next_hops_fee_msat,
1321 path_value_msat, aggregate_next_hops_path_htlc_minimum_msat,
1322 aggregate_next_hops_path_penalty_msat,
1323 aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length) {
1324 // If this hop was not used then there is no use checking the preceding
1325 // hops in the RouteHint. We can break by just searching for a direct
1326 // channel between last checked hop and first_hop_targets.
1330 let used_liquidity_msat = used_channel_liquidities
1331 .get(&(hop.short_channel_id, source < target)).copied().unwrap_or(0);
1332 let channel_usage = ChannelUsage {
1333 amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
1334 inflight_htlc_msat: used_liquidity_msat,
1335 effective_capacity: candidate.effective_capacity(),
1337 let channel_penalty_msat = scorer.channel_penalty_msat(
1338 hop.short_channel_id, &source, &target, channel_usage
1340 aggregate_next_hops_path_penalty_msat = aggregate_next_hops_path_penalty_msat
1341 .saturating_add(channel_penalty_msat);
1343 aggregate_next_hops_cltv_delta = aggregate_next_hops_cltv_delta
1344 .saturating_add(hop.cltv_expiry_delta as u32);
1346 aggregate_next_hops_path_length = aggregate_next_hops_path_length
1349 // Searching for a direct channel between last checked hop and first_hop_targets
1350 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&prev_hop_id)) {
1351 for details in first_channels {
1352 let candidate = CandidateRouteHop::FirstHop { details };
1353 add_entry!(candidate, our_node_id, NodeId::from_pubkey(&prev_hop_id),
1354 aggregate_next_hops_fee_msat, path_value_msat,
1355 aggregate_next_hops_path_htlc_minimum_msat,
1356 aggregate_next_hops_path_penalty_msat, aggregate_next_hops_cltv_delta,
1357 aggregate_next_hops_path_length);
1365 // In the next values of the iterator, the aggregate fees already reflects
1366 // the sum of value sent from payer (final_value_msat) and routing fees
1367 // for the last node in the RouteHint. We need to just add the fees to
1368 // route through the current node so that the preceding node (next iteration)
1370 let hops_fee = compute_fees(aggregate_next_hops_fee_msat + final_value_msat, hop.fees)
1371 .map_or(None, |inc| inc.checked_add(aggregate_next_hops_fee_msat));
1372 aggregate_next_hops_fee_msat = if let Some(val) = hops_fee { val } else { break; };
1374 let hop_htlc_minimum_msat = candidate.htlc_minimum_msat();
1375 let hop_htlc_minimum_msat_inc = if let Some(val) = compute_fees(aggregate_next_hops_path_htlc_minimum_msat, hop.fees) { val } else { break; };
1376 let hops_path_htlc_minimum = aggregate_next_hops_path_htlc_minimum_msat
1377 .checked_add(hop_htlc_minimum_msat_inc);
1378 aggregate_next_hops_path_htlc_minimum_msat = if let Some(val) = hops_path_htlc_minimum { cmp::max(hop_htlc_minimum_msat, val) } else { break; };
1380 if idx == route.0.len() - 1 {
1381 // The last hop in this iterator is the first hop in
1382 // overall RouteHint.
1383 // If this hop connects to a node with which we have a direct channel,
1384 // ignore the network graph and, if the last hop was added, add our
1385 // direct channel to the candidate set.
1387 // Note that we *must* check if the last hop was added as `add_entry`
1388 // always assumes that the third argument is a node to which we have a
1390 if let Some(first_channels) = first_hop_targets.get(&NodeId::from_pubkey(&hop.src_node_id)) {
1391 for details in first_channels {
1392 let candidate = CandidateRouteHop::FirstHop { details };
1393 add_entry!(candidate, our_node_id,
1394 NodeId::from_pubkey(&hop.src_node_id),
1395 aggregate_next_hops_fee_msat, path_value_msat,
1396 aggregate_next_hops_path_htlc_minimum_msat,
1397 aggregate_next_hops_path_penalty_msat,
1398 aggregate_next_hops_cltv_delta,
1399 aggregate_next_hops_path_length);
1407 log_trace!(logger, "Starting main path collection loop with {} nodes pre-filled from first/last hops.", targets.len());
1409 // At this point, targets are filled with the data from first and
1410 // last hops communicated by the caller, and the payment receiver.
1411 let mut found_new_path = false;
1414 // If this loop terminates due the exhaustion of targets, two situations are possible:
1415 // - not enough outgoing liquidity:
1416 // 0 < already_collected_value_msat < final_value_msat
1417 // - enough outgoing liquidity:
1418 // final_value_msat <= already_collected_value_msat < recommended_value_msat
1419 // Both these cases (and other cases except reaching recommended_value_msat) mean that
1420 // paths_collection will be stopped because found_new_path==false.
1421 // This is not necessarily a routing failure.
1422 '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() {
1424 // Since we're going payee-to-payer, hitting our node as a target means we should stop
1425 // traversing the graph and arrange the path out of what we found.
1426 if node_id == our_node_id {
1427 let mut new_entry = dist.remove(&our_node_id).unwrap();
1428 let mut ordered_hops: Vec<(PathBuildingHop, NodeFeatures)> = vec!((new_entry.clone(), default_node_features.clone()));
1431 let mut features_set = false;
1432 if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
1433 for details in first_channels {
1434 if details.get_outbound_payment_scid().unwrap() == ordered_hops.last().unwrap().0.candidate.short_channel_id() {
1435 ordered_hops.last_mut().unwrap().1 = details.counterparty.features.to_context();
1436 features_set = true;
1442 if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
1443 if let Some(node_info) = node.announcement_info.as_ref() {
1444 ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
1446 ordered_hops.last_mut().unwrap().1 = default_node_features.clone();
1449 // We can fill in features for everything except hops which were
1450 // provided via the invoice we're paying. We could guess based on the
1451 // recipient's features but for now we simply avoid guessing at all.
1455 // Means we succesfully traversed from the payer to the payee, now
1456 // save this path for the payment route. Also, update the liquidity
1457 // remaining on the used hops, so that we take them into account
1458 // while looking for more paths.
1459 if ordered_hops.last().unwrap().0.node_id == payee_node_id {
1463 new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
1464 Some(payment_hop) => payment_hop,
1465 // We can't arrive at None because, if we ever add an entry to targets,
1466 // we also fill in the entry in dist (see add_entry!).
1467 None => unreachable!(),
1469 // We "propagate" the fees one hop backward (topologically) here,
1470 // so that fees paid for a HTLC forwarding on the current channel are
1471 // associated with the previous channel (where they will be subtracted).
1472 ordered_hops.last_mut().unwrap().0.fee_msat = new_entry.hop_use_fee_msat;
1473 ordered_hops.push((new_entry.clone(), default_node_features.clone()));
1475 ordered_hops.last_mut().unwrap().0.fee_msat = value_contribution_msat;
1476 ordered_hops.last_mut().unwrap().0.hop_use_fee_msat = 0;
1478 log_trace!(logger, "Found a path back to us from the target with {} hops contributing up to {} msat: \n {:#?}",
1479 ordered_hops.len(), value_contribution_msat, ordered_hops.iter().map(|h| &(h.0)).collect::<Vec<&PathBuildingHop>>());
1481 let mut payment_path = PaymentPath {hops: ordered_hops};
1483 // We could have possibly constructed a slightly inconsistent path: since we reduce
1484 // value being transferred along the way, we could have violated htlc_minimum_msat
1485 // on some channels we already passed (assuming dest->source direction). Here, we
1486 // recompute the fees again, so that if that's the case, we match the currently
1487 // underpaid htlc_minimum_msat with fees.
1488 payment_path.update_value_and_recompute_fees(cmp::min(value_contribution_msat, final_value_msat));
1490 // Since a path allows to transfer as much value as
1491 // the smallest channel it has ("bottleneck"), we should recompute
1492 // the fees so sender HTLC don't overpay fees when traversing
1493 // larger channels than the bottleneck. This may happen because
1494 // when we were selecting those channels we were not aware how much value
1495 // this path will transfer, and the relative fee for them
1496 // might have been computed considering a larger value.
1497 // Remember that we used these channels so that we don't rely
1498 // on the same liquidity in future paths.
1499 let mut prevented_redundant_path_selection = false;
1500 let prev_hop_iter = core::iter::once(&our_node_id)
1501 .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
1502 for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
1503 let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
1504 let used_liquidity_msat = used_channel_liquidities
1505 .entry((hop.candidate.short_channel_id(), *prev_hop < hop.node_id))
1506 .and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
1507 .or_insert(spent_on_hop_msat);
1508 if *used_liquidity_msat == hop.candidate.htlc_maximum_msat() {
1509 // If this path used all of this channel's available liquidity, we know
1510 // this path will not be selected again in the next loop iteration.
1511 prevented_redundant_path_selection = true;
1513 debug_assert!(*used_liquidity_msat <= hop.candidate.htlc_maximum_msat());
1515 if !prevented_redundant_path_selection {
1516 // If we weren't capped by hitting a liquidity limit on a channel in the path,
1517 // we'll probably end up picking the same path again on the next iteration.
1518 // Decrease the available liquidity of a hop in the middle of the path.
1519 let victim_scid = payment_path.hops[(payment_path.hops.len()) / 2].0.candidate.short_channel_id();
1520 let exhausted = u64::max_value();
1521 log_trace!(logger, "Disabling channel {} for future path building iterations to avoid duplicates.", victim_scid);
1522 *used_channel_liquidities.entry((victim_scid, false)).or_default() = exhausted;
1523 *used_channel_liquidities.entry((victim_scid, true)).or_default() = exhausted;
1526 // Track the total amount all our collected paths allow to send so that we know
1527 // when to stop looking for more paths
1528 already_collected_value_msat += value_contribution_msat;
1530 payment_paths.push(payment_path);
1531 found_new_path = true;
1532 break 'path_construction;
1535 // If we found a path back to the payee, we shouldn't try to process it again. This is
1536 // the equivalent of the `elem.was_processed` check in
1537 // add_entries_to_cheapest_to_target_node!() (see comment there for more info).
1538 if node_id == payee_node_id { continue 'path_construction; }
1540 // Otherwise, since the current target node is not us,
1541 // keep "unrolling" the payment graph from payee to payer by
1542 // finding a way to reach the current target from the payer side.
1543 match network_nodes.get(&node_id) {
1546 add_entries_to_cheapest_to_target_node!(node, node_id, lowest_fee_to_node,
1547 value_contribution_msat, path_htlc_minimum_msat, path_penalty_msat,
1548 total_cltv_delta, path_length_to_node);
1554 // If we don't support MPP, no use trying to gather more value ever.
1555 break 'paths_collection;
1559 // Stop either when the recommended value is reached or if no new path was found in this
1561 // In the latter case, making another path finding attempt won't help,
1562 // because we deterministically terminated the search due to low liquidity.
1563 if already_collected_value_msat >= recommended_value_msat || !found_new_path {
1564 log_trace!(logger, "Have now collected {} msat (seeking {} msat) in paths. Last path loop {} a new path.",
1565 already_collected_value_msat, recommended_value_msat, if found_new_path { "found" } else { "did not find" });
1566 break 'paths_collection;
1567 } else if found_new_path && already_collected_value_msat == final_value_msat && payment_paths.len() == 1 {
1568 // Further, if this was our first walk of the graph, and we weren't limited by an
1569 // htlc_minimum_msat, return immediately because this path should suffice. If we were
1570 // limited by an htlc_minimum_msat value, find another path with a higher value,
1571 // potentially allowing us to pay fees to meet the htlc_minimum on the new path while
1572 // still keeping a lower total fee than this path.
1573 if !hit_minimum_limit {
1574 log_trace!(logger, "Collected exactly our payment amount on the first pass, without hitting an htlc_minimum_msat limit, exiting.");
1575 break 'paths_collection;
1577 log_trace!(logger, "Collected our payment amount on the first pass, but running again to collect extra paths with a potentially higher limit.");
1578 path_value_msat = recommended_value_msat;
1583 if payment_paths.len() == 0 {
1584 return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1587 if already_collected_value_msat < final_value_msat {
1588 return Err(LightningError{err: "Failed to find a sufficient route to the given destination".to_owned(), action: ErrorAction::IgnoreError});
1591 // Sort by total fees and take the best paths.
1592 payment_paths.sort_unstable_by_key(|path| path.get_total_fee_paid_msat());
1593 if payment_paths.len() > 50 {
1594 payment_paths.truncate(50);
1597 // Draw multiple sufficient routes by randomly combining the selected paths.
1598 let mut drawn_routes = Vec::new();
1599 let mut prng = ChaCha20::new(random_seed_bytes, &[0u8; 12]);
1600 let mut random_index_bytes = [0u8; ::core::mem::size_of::<usize>()];
1602 let num_permutations = payment_paths.len();
1603 for _ in 0..num_permutations {
1604 let mut cur_route = Vec::<PaymentPath>::new();
1605 let mut aggregate_route_value_msat = 0;
1608 // Do a Fisher-Yates shuffle to create a random permutation of the payment paths
1609 for cur_index in (1..payment_paths.len()).rev() {
1610 prng.process_in_place(&mut random_index_bytes);
1611 let random_index = usize::from_be_bytes(random_index_bytes).wrapping_rem(cur_index+1);
1612 payment_paths.swap(cur_index, random_index);
1616 for payment_path in &payment_paths {
1617 cur_route.push(payment_path.clone());
1618 aggregate_route_value_msat += payment_path.get_value_msat();
1619 if aggregate_route_value_msat > final_value_msat {
1620 // Last path likely overpaid. Substract it from the most expensive
1621 // (in terms of proportional fee) path in this route and recompute fees.
1622 // This might be not the most economically efficient way, but fewer paths
1623 // also makes routing more reliable.
1624 let mut overpaid_value_msat = aggregate_route_value_msat - final_value_msat;
1626 // First, we drop some expensive low-value paths entirely if possible, since fewer
1627 // paths is better: the payment is less likely to fail. In order to do so, we sort
1628 // by value and fall back to total fees paid, i.e., in case of equal values we
1629 // prefer lower cost paths.
1630 cur_route.sort_unstable_by(|a, b| {
1631 a.get_value_msat().cmp(&b.get_value_msat())
1632 // Reverse ordering for cost, so we drop higher-cost paths first
1633 .then_with(|| b.get_cost_msat().cmp(&a.get_cost_msat()))
1636 // We should make sure that at least 1 path left.
1637 let mut paths_left = cur_route.len();
1638 cur_route.retain(|path| {
1639 if paths_left == 1 {
1642 let mut keep = true;
1643 let path_value_msat = path.get_value_msat();
1644 if path_value_msat <= overpaid_value_msat {
1646 overpaid_value_msat -= path_value_msat;
1652 if overpaid_value_msat == 0 {
1656 assert!(cur_route.len() > 0);
1659 // Now, subtract the overpaid value from the most-expensive path.
1660 // TODO: this could also be optimized by also sorting by feerate_per_sat_routed,
1661 // so that the sender pays less fees overall. And also htlc_minimum_msat.
1662 cur_route.sort_unstable_by_key(|path| { path.hops.iter().map(|hop| hop.0.candidate.fees().proportional_millionths as u64).sum::<u64>() });
1663 let expensive_payment_path = cur_route.first_mut().unwrap();
1665 // We already dropped all the small value paths above, meaning all the
1666 // remaining paths are larger than remaining overpaid_value_msat.
1667 // Thus, this can't be negative.
1668 let expensive_path_new_value_msat = expensive_payment_path.get_value_msat() - overpaid_value_msat;
1669 expensive_payment_path.update_value_and_recompute_fees(expensive_path_new_value_msat);
1673 drawn_routes.push(cur_route);
1677 // Select the best route by lowest total cost.
1678 drawn_routes.sort_unstable_by_key(|paths| paths.iter().map(|path| path.get_cost_msat()).sum::<u64>());
1679 let mut selected_paths = Vec::<Vec<Result<RouteHop, LightningError>>>::new();
1680 for payment_path in drawn_routes.first().unwrap() {
1681 let mut path = payment_path.hops.iter().map(|(payment_hop, node_features)| {
1683 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)})?,
1684 node_features: node_features.clone(),
1685 short_channel_id: payment_hop.candidate.short_channel_id(),
1686 channel_features: payment_hop.candidate.features(),
1687 fee_msat: payment_hop.fee_msat,
1688 cltv_expiry_delta: payment_hop.candidate.cltv_expiry_delta(),
1690 }).collect::<Vec<_>>();
1691 // Propagate the cltv_expiry_delta one hop backwards since the delta from the current hop is
1692 // applicable for the previous hop.
1693 path.iter_mut().rev().fold(final_cltv_expiry_delta, |prev_cltv_expiry_delta, hop| {
1694 core::mem::replace(&mut hop.as_mut().unwrap().cltv_expiry_delta, prev_cltv_expiry_delta)
1696 selected_paths.push(path);
1698 // Make sure we would never create a route with more paths than we allow.
1699 debug_assert!(selected_paths.len() <= payment_params.max_path_count.into());
1701 if let Some(features) = &payment_params.features {
1702 for path in selected_paths.iter_mut() {
1703 if let Ok(route_hop) = path.last_mut().unwrap() {
1704 route_hop.node_features = features.to_context();
1710 paths: selected_paths.into_iter().map(|path| path.into_iter().collect()).collect::<Result<Vec<_>, _>>()?,
1711 payment_params: Some(payment_params.clone()),
1713 log_info!(logger, "Got route to {}: {}", payment_params.payee_pubkey, log_route!(route));
1717 // When an adversarial intermediary node observes a payment, it may be able to infer its
1718 // destination, if the remaining CLTV expiry delta exactly matches a feasible path in the network
1719 // graph. In order to improve privacy, this method obfuscates the CLTV expiry deltas along the
1720 // payment path by adding a randomized 'shadow route' offset to the final hop.
1721 fn add_random_cltv_offset(route: &mut Route, payment_params: &PaymentParameters,
1722 network_graph: &ReadOnlyNetworkGraph, random_seed_bytes: &[u8; 32]
1724 let network_channels = network_graph.channels();
1725 let network_nodes = network_graph.nodes();
1727 for path in route.paths.iter_mut() {
1728 let mut shadow_ctlv_expiry_delta_offset: u32 = 0;
1730 // Remember the last three nodes of the random walk and avoid looping back on them.
1731 // Init with the last three nodes from the actual path, if possible.
1732 let mut nodes_to_avoid: [NodeId; 3] = [NodeId::from_pubkey(&path.last().unwrap().pubkey),
1733 NodeId::from_pubkey(&path.get(path.len().saturating_sub(2)).unwrap().pubkey),
1734 NodeId::from_pubkey(&path.get(path.len().saturating_sub(3)).unwrap().pubkey)];
1736 // Choose the last publicly known node as the starting point for the random walk.
1737 let mut cur_hop: Option<NodeId> = None;
1738 let mut path_nonce = [0u8; 12];
1739 if let Some(starting_hop) = path.iter().rev()
1740 .find(|h| network_nodes.contains_key(&NodeId::from_pubkey(&h.pubkey))) {
1741 cur_hop = Some(NodeId::from_pubkey(&starting_hop.pubkey));
1742 path_nonce.copy_from_slice(&cur_hop.unwrap().as_slice()[..12]);
1745 // Init PRNG with the path-dependant nonce, which is static for private paths.
1746 let mut prng = ChaCha20::new(random_seed_bytes, &path_nonce);
1747 let mut random_path_bytes = [0u8; ::core::mem::size_of::<usize>()];
1749 // Pick a random path length in [1 .. 3]
1750 prng.process_in_place(&mut random_path_bytes);
1751 let random_walk_length = usize::from_be_bytes(random_path_bytes).wrapping_rem(3).wrapping_add(1);
1753 for random_hop in 0..random_walk_length {
1754 // If we don't find a suitable offset in the public network graph, we default to
1755 // MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1756 let mut random_hop_offset = MEDIAN_HOP_CLTV_EXPIRY_DELTA;
1758 if let Some(cur_node_id) = cur_hop {
1759 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
1760 // Randomly choose the next unvisited hop.
1761 prng.process_in_place(&mut random_path_bytes);
1762 if let Some(random_channel) = usize::from_be_bytes(random_path_bytes)
1763 .checked_rem(cur_node.channels.len())
1764 .and_then(|index| cur_node.channels.get(index))
1765 .and_then(|id| network_channels.get(id)) {
1766 random_channel.as_directed_from(&cur_node_id).map(|(dir_info, next_id)| {
1767 if !nodes_to_avoid.iter().any(|x| x == next_id) {
1768 nodes_to_avoid[random_hop] = *next_id;
1769 dir_info.direction().map(|channel_update_info| {
1770 random_hop_offset = channel_update_info.cltv_expiry_delta.into();
1771 cur_hop = Some(*next_id);
1779 shadow_ctlv_expiry_delta_offset = shadow_ctlv_expiry_delta_offset
1780 .checked_add(random_hop_offset)
1781 .unwrap_or(shadow_ctlv_expiry_delta_offset);
1784 // Limit the total offset to reduce the worst-case locked liquidity timevalue
1785 const MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET: u32 = 3*144;
1786 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, MAX_SHADOW_CLTV_EXPIRY_DELTA_OFFSET);
1788 // Limit the offset so we never exceed the max_total_cltv_expiry_delta. To improve plausibility,
1789 // we choose the limit to be the largest possible multiple of MEDIAN_HOP_CLTV_EXPIRY_DELTA.
1790 let path_total_cltv_expiry_delta: u32 = path.iter().map(|h| h.cltv_expiry_delta).sum();
1791 let mut max_path_offset = payment_params.max_total_cltv_expiry_delta - path_total_cltv_expiry_delta;
1792 max_path_offset = cmp::max(
1793 max_path_offset - (max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA),
1794 max_path_offset % MEDIAN_HOP_CLTV_EXPIRY_DELTA);
1795 shadow_ctlv_expiry_delta_offset = cmp::min(shadow_ctlv_expiry_delta_offset, max_path_offset);
1797 // Add 'shadow' CLTV offset to the final hop
1798 if let Some(last_hop) = path.last_mut() {
1799 last_hop.cltv_expiry_delta = last_hop.cltv_expiry_delta
1800 .checked_add(shadow_ctlv_expiry_delta_offset).unwrap_or(last_hop.cltv_expiry_delta);
1805 /// Construct a route from us (payer) to the target node (payee) via the given hops (which should
1806 /// exclude the payer, but include the payee). This may be useful, e.g., for probing the chosen path.
1808 /// Re-uses logic from `find_route`, so the restrictions described there also apply here.
1809 pub fn build_route_from_hops<L: Deref, GL: Deref>(
1810 our_node_pubkey: &PublicKey, hops: &[PublicKey], route_params: &RouteParameters,
1811 network_graph: &NetworkGraph<GL>, logger: L, random_seed_bytes: &[u8; 32]
1812 ) -> Result<Route, LightningError>
1813 where L::Target: Logger, GL::Target: Logger {
1814 let graph_lock = network_graph.read_only();
1815 let mut route = build_route_from_hops_internal(
1816 our_node_pubkey, hops, &route_params.payment_params, &graph_lock,
1817 route_params.final_value_msat, route_params.final_cltv_expiry_delta, logger, random_seed_bytes)?;
1818 add_random_cltv_offset(&mut route, &route_params.payment_params, &graph_lock, random_seed_bytes);
1822 fn build_route_from_hops_internal<L: Deref>(
1823 our_node_pubkey: &PublicKey, hops: &[PublicKey], payment_params: &PaymentParameters,
1824 network_graph: &ReadOnlyNetworkGraph, final_value_msat: u64, final_cltv_expiry_delta: u32,
1825 logger: L, random_seed_bytes: &[u8; 32]
1826 ) -> Result<Route, LightningError> where L::Target: Logger {
1829 our_node_id: NodeId,
1830 hop_ids: [Option<NodeId>; MAX_PATH_LENGTH_ESTIMATE as usize],
1833 impl Score for HopScorer {
1834 fn channel_penalty_msat(&self, _short_channel_id: u64, source: &NodeId, target: &NodeId,
1835 _usage: ChannelUsage) -> u64
1837 let mut cur_id = self.our_node_id;
1838 for i in 0..self.hop_ids.len() {
1839 if let Some(next_id) = self.hop_ids[i] {
1840 if cur_id == *source && next_id == *target {
1851 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
1853 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
1855 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
1857 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
1860 impl<'a> Writeable for HopScorer {
1862 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), io::Error> {
1867 if hops.len() > MAX_PATH_LENGTH_ESTIMATE.into() {
1868 return Err(LightningError{err: "Cannot build a route exceeding the maximum path length.".to_owned(), action: ErrorAction::IgnoreError});
1871 let our_node_id = NodeId::from_pubkey(our_node_pubkey);
1872 let mut hop_ids = [None; MAX_PATH_LENGTH_ESTIMATE as usize];
1873 for i in 0..hops.len() {
1874 hop_ids[i] = Some(NodeId::from_pubkey(&hops[i]));
1877 let scorer = HopScorer { our_node_id, hop_ids };
1879 get_route(our_node_pubkey, payment_params, network_graph, None, final_value_msat,
1880 final_cltv_expiry_delta, logger, &scorer, random_seed_bytes)
1885 use routing::gossip::{NetworkGraph, P2PGossipSync, NodeId, EffectiveCapacity};
1886 use routing::router::{get_route, build_route_from_hops_internal, add_random_cltv_offset, default_node_features,
1887 PaymentParameters, Route, RouteHint, RouteHintHop, RouteHop, RoutingFees,
1888 DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA, MAX_PATH_LENGTH_ESTIMATE};
1889 use routing::scoring::{ChannelUsage, Score, ProbabilisticScorer, ProbabilisticScoringParameters};
1890 use chain::transaction::OutPoint;
1891 use chain::keysinterface::KeysInterface;
1892 use ln::features::{ChannelFeatures, InitFeatures, InvoiceFeatures, NodeFeatures};
1893 use ln::msgs::{ErrorAction, LightningError, OptionalField, UnsignedChannelAnnouncement, ChannelAnnouncement, RoutingMessageHandler,
1894 NodeAnnouncement, UnsignedNodeAnnouncement, ChannelUpdate, UnsignedChannelUpdate};
1895 use ln::channelmanager;
1896 use util::test_utils;
1897 use util::chacha20::ChaCha20;
1898 use util::ser::Writeable;
1900 use util::ser::Writer;
1902 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
1903 use bitcoin::hashes::Hash;
1904 use bitcoin::network::constants::Network;
1905 use bitcoin::blockdata::constants::genesis_block;
1906 use bitcoin::blockdata::script::Builder;
1907 use bitcoin::blockdata::opcodes;
1908 use bitcoin::blockdata::transaction::TxOut;
1912 use bitcoin::secp256k1::{PublicKey,SecretKey};
1913 use bitcoin::secp256k1::{Secp256k1, All};
1916 use sync::{self, Arc};
1918 fn get_channel_details(short_channel_id: Option<u64>, node_id: PublicKey,
1919 features: InitFeatures, outbound_capacity_msat: u64) -> channelmanager::ChannelDetails {
1920 channelmanager::ChannelDetails {
1921 channel_id: [0; 32],
1922 counterparty: channelmanager::ChannelCounterparty {
1925 unspendable_punishment_reserve: 0,
1926 forwarding_info: None,
1927 outbound_htlc_minimum_msat: None,
1928 outbound_htlc_maximum_msat: None,
1930 funding_txo: Some(OutPoint { txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0 }),
1933 outbound_scid_alias: None,
1934 inbound_scid_alias: None,
1935 channel_value_satoshis: 0,
1938 outbound_capacity_msat,
1939 next_outbound_htlc_limit_msat: outbound_capacity_msat,
1940 inbound_capacity_msat: 42,
1941 unspendable_punishment_reserve: None,
1942 confirmations_required: None,
1943 force_close_spend_delay: None,
1944 is_outbound: true, is_channel_ready: true,
1945 is_usable: true, is_public: true,
1946 inbound_htlc_minimum_msat: None,
1947 inbound_htlc_maximum_msat: None,
1952 // Using the same keys for LN and BTC ids
1954 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1955 secp_ctx: &Secp256k1<All>, node_1_privkey: &SecretKey, node_2_privkey: &SecretKey, features: ChannelFeatures, short_channel_id: u64
1957 let node_id_1 = PublicKey::from_secret_key(&secp_ctx, node_1_privkey);
1958 let node_id_2 = PublicKey::from_secret_key(&secp_ctx, node_2_privkey);
1960 let unsigned_announcement = UnsignedChannelAnnouncement {
1962 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
1966 bitcoin_key_1: node_id_1,
1967 bitcoin_key_2: node_id_2,
1968 excess_data: Vec::new(),
1971 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
1972 let valid_announcement = ChannelAnnouncement {
1973 node_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1974 node_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1975 bitcoin_signature_1: secp_ctx.sign_ecdsa(&msghash, node_1_privkey),
1976 bitcoin_signature_2: secp_ctx.sign_ecdsa(&msghash, node_2_privkey),
1977 contents: unsigned_announcement.clone(),
1979 match gossip_sync.handle_channel_announcement(&valid_announcement) {
1980 Ok(res) => assert!(res),
1986 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
1987 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, update: UnsignedChannelUpdate
1989 let msghash = hash_to_message!(&Sha256dHash::hash(&update.encode()[..])[..]);
1990 let valid_channel_update = ChannelUpdate {
1991 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
1992 contents: update.clone()
1995 match gossip_sync.handle_channel_update(&valid_channel_update) {
1996 Ok(res) => assert!(res),
2001 fn add_or_update_node(
2002 gossip_sync: &P2PGossipSync<Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, Arc<test_utils::TestChainSource>, Arc<test_utils::TestLogger>>,
2003 secp_ctx: &Secp256k1<All>, node_privkey: &SecretKey, features: NodeFeatures, timestamp: u32
2005 let node_id = PublicKey::from_secret_key(&secp_ctx, node_privkey);
2006 let unsigned_announcement = UnsignedNodeAnnouncement {
2012 addresses: Vec::new(),
2013 excess_address_data: Vec::new(),
2014 excess_data: Vec::new(),
2016 let msghash = hash_to_message!(&Sha256dHash::hash(&unsigned_announcement.encode()[..])[..]);
2017 let valid_announcement = NodeAnnouncement {
2018 signature: secp_ctx.sign_ecdsa(&msghash, node_privkey),
2019 contents: unsigned_announcement.clone()
2022 match gossip_sync.handle_node_announcement(&valid_announcement) {
2028 fn get_nodes(secp_ctx: &Secp256k1<All>) -> (SecretKey, PublicKey, Vec<SecretKey>, Vec<PublicKey>) {
2029 let privkeys: Vec<SecretKey> = (2..22).map(|i| {
2030 SecretKey::from_slice(&hex::decode(format!("{:02x}", i).repeat(32)).unwrap()[..]).unwrap()
2033 let pubkeys = privkeys.iter().map(|secret| PublicKey::from_secret_key(&secp_ctx, secret)).collect();
2035 let our_privkey = SecretKey::from_slice(&hex::decode("01".repeat(32)).unwrap()[..]).unwrap();
2036 let our_id = PublicKey::from_secret_key(&secp_ctx, &our_privkey);
2038 (our_privkey, our_id, privkeys, pubkeys)
2041 fn id_to_feature_flags(id: u8) -> Vec<u8> {
2042 // Set the feature flags to the id'th odd (ie non-required) feature bit so that we can
2043 // test for it later.
2044 let idx = (id - 1) * 2 + 1;
2046 vec![1 << (idx - 8*3), 0, 0, 0]
2047 } else if idx > 8*2 {
2048 vec![1 << (idx - 8*2), 0, 0]
2049 } else if idx > 8*1 {
2050 vec![1 << (idx - 8*1), 0]
2056 fn build_line_graph() -> (
2057 Secp256k1<All>, sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2058 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2059 sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>,
2061 let secp_ctx = Secp256k1::new();
2062 let logger = Arc::new(test_utils::TestLogger::new());
2063 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2064 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2065 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2066 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2068 // Build network from our_id to node 19:
2069 // our_id -1(1)2- node0 -1(2)2- node1 - ... - node19
2070 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2072 for (idx, (cur_privkey, next_privkey)) in core::iter::once(&our_privkey)
2073 .chain(privkeys.iter()).zip(privkeys.iter()).enumerate() {
2074 let cur_short_channel_id = (idx as u64) + 1;
2075 add_channel(&gossip_sync, &secp_ctx, &cur_privkey, &next_privkey,
2076 ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), cur_short_channel_id);
2077 update_channel(&gossip_sync, &secp_ctx, &cur_privkey, UnsignedChannelUpdate {
2078 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2079 short_channel_id: cur_short_channel_id,
2080 timestamp: idx as u32,
2082 cltv_expiry_delta: 0,
2083 htlc_minimum_msat: 0,
2084 htlc_maximum_msat: OptionalField::Absent,
2086 fee_proportional_millionths: 0,
2087 excess_data: Vec::new()
2089 update_channel(&gossip_sync, &secp_ctx, &next_privkey, UnsignedChannelUpdate {
2090 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2091 short_channel_id: cur_short_channel_id,
2092 timestamp: (idx as u32)+1,
2094 cltv_expiry_delta: 0,
2095 htlc_minimum_msat: 0,
2096 htlc_maximum_msat: OptionalField::Absent,
2098 fee_proportional_millionths: 0,
2099 excess_data: Vec::new()
2101 add_or_update_node(&gossip_sync, &secp_ctx, next_privkey,
2102 NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2105 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2108 fn build_graph() -> (
2110 sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>,
2111 P2PGossipSync<sync::Arc<NetworkGraph<Arc<test_utils::TestLogger>>>, sync::Arc<test_utils::TestChainSource>, sync::Arc<test_utils::TestLogger>>,
2112 sync::Arc<test_utils::TestChainSource>,
2113 sync::Arc<test_utils::TestLogger>,
2115 let secp_ctx = Secp256k1::new();
2116 let logger = Arc::new(test_utils::TestLogger::new());
2117 let chain_monitor = Arc::new(test_utils::TestChainSource::new(Network::Testnet));
2118 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
2119 let network_graph = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
2120 let gossip_sync = P2PGossipSync::new(Arc::clone(&network_graph), None, Arc::clone(&logger));
2121 // Build network from our_id to node6:
2123 // -1(1)2- node0 -1(3)2-
2125 // our_id -1(12)2- node7 -1(13)2--- node2
2127 // -1(2)2- node1 -1(4)2-
2130 // chan1 1-to-2: disabled
2131 // chan1 2-to-1: enabled, 0 fee
2133 // chan2 1-to-2: enabled, ignored fee
2134 // chan2 2-to-1: enabled, 0 fee
2136 // chan3 1-to-2: enabled, 0 fee
2137 // chan3 2-to-1: enabled, 100 msat fee
2139 // chan4 1-to-2: enabled, 100% fee
2140 // chan4 2-to-1: enabled, 0 fee
2142 // chan12 1-to-2: enabled, ignored fee
2143 // chan12 2-to-1: enabled, 0 fee
2145 // chan13 1-to-2: enabled, 200% fee
2146 // chan13 2-to-1: enabled, 0 fee
2149 // -1(5)2- node3 -1(8)2--
2153 // node2--1(6)2- node4 -1(9)2--- node6 (not in global route map)
2155 // -1(7)2- node5 -1(10)2-
2157 // Channels 5, 8, 9 and 10 are private channels.
2159 // chan5 1-to-2: enabled, 100 msat fee
2160 // chan5 2-to-1: enabled, 0 fee
2162 // chan6 1-to-2: enabled, 0 fee
2163 // chan6 2-to-1: enabled, 0 fee
2165 // chan7 1-to-2: enabled, 100% fee
2166 // chan7 2-to-1: enabled, 0 fee
2168 // chan8 1-to-2: enabled, variable fee (0 then 1000 msat)
2169 // chan8 2-to-1: enabled, 0 fee
2171 // chan9 1-to-2: enabled, 1001 msat fee
2172 // chan9 2-to-1: enabled, 0 fee
2174 // chan10 1-to-2: enabled, 0 fee
2175 // chan10 2-to-1: enabled, 0 fee
2177 // chan11 1-to-2: enabled, 0 fee
2178 // chan11 2-to-1: enabled, 0 fee
2180 let (our_privkey, _, privkeys, _) = get_nodes(&secp_ctx);
2182 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[0], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
2183 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2184 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2185 short_channel_id: 1,
2188 cltv_expiry_delta: 0,
2189 htlc_minimum_msat: 0,
2190 htlc_maximum_msat: OptionalField::Absent,
2192 fee_proportional_millionths: 0,
2193 excess_data: Vec::new()
2196 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
2198 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
2199 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2200 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2201 short_channel_id: 2,
2204 cltv_expiry_delta: (5 << 4) | 3,
2205 htlc_minimum_msat: 0,
2206 htlc_maximum_msat: OptionalField::Absent,
2207 fee_base_msat: u32::max_value(),
2208 fee_proportional_millionths: u32::max_value(),
2209 excess_data: Vec::new()
2211 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2212 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2213 short_channel_id: 2,
2216 cltv_expiry_delta: 0,
2217 htlc_minimum_msat: 0,
2218 htlc_maximum_msat: OptionalField::Absent,
2220 fee_proportional_millionths: 0,
2221 excess_data: Vec::new()
2224 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
2226 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[7], ChannelFeatures::from_le_bytes(id_to_feature_flags(12)), 12);
2227 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2228 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2229 short_channel_id: 12,
2232 cltv_expiry_delta: (5 << 4) | 3,
2233 htlc_minimum_msat: 0,
2234 htlc_maximum_msat: OptionalField::Absent,
2235 fee_base_msat: u32::max_value(),
2236 fee_proportional_millionths: u32::max_value(),
2237 excess_data: Vec::new()
2239 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2240 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2241 short_channel_id: 12,
2244 cltv_expiry_delta: 0,
2245 htlc_minimum_msat: 0,
2246 htlc_maximum_msat: OptionalField::Absent,
2248 fee_proportional_millionths: 0,
2249 excess_data: Vec::new()
2252 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], NodeFeatures::from_le_bytes(id_to_feature_flags(8)), 0);
2254 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
2255 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2256 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2257 short_channel_id: 3,
2260 cltv_expiry_delta: (3 << 4) | 1,
2261 htlc_minimum_msat: 0,
2262 htlc_maximum_msat: OptionalField::Absent,
2264 fee_proportional_millionths: 0,
2265 excess_data: Vec::new()
2267 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2268 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2269 short_channel_id: 3,
2272 cltv_expiry_delta: (3 << 4) | 2,
2273 htlc_minimum_msat: 0,
2274 htlc_maximum_msat: OptionalField::Absent,
2276 fee_proportional_millionths: 0,
2277 excess_data: Vec::new()
2280 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
2281 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2282 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2283 short_channel_id: 4,
2286 cltv_expiry_delta: (4 << 4) | 1,
2287 htlc_minimum_msat: 0,
2288 htlc_maximum_msat: OptionalField::Absent,
2290 fee_proportional_millionths: 1000000,
2291 excess_data: Vec::new()
2293 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2294 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2295 short_channel_id: 4,
2298 cltv_expiry_delta: (4 << 4) | 2,
2299 htlc_minimum_msat: 0,
2300 htlc_maximum_msat: OptionalField::Absent,
2302 fee_proportional_millionths: 0,
2303 excess_data: Vec::new()
2306 add_channel(&gossip_sync, &secp_ctx, &privkeys[7], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(13)), 13);
2307 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2308 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2309 short_channel_id: 13,
2312 cltv_expiry_delta: (13 << 4) | 1,
2313 htlc_minimum_msat: 0,
2314 htlc_maximum_msat: OptionalField::Absent,
2316 fee_proportional_millionths: 2000000,
2317 excess_data: Vec::new()
2319 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2320 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2321 short_channel_id: 13,
2324 cltv_expiry_delta: (13 << 4) | 2,
2325 htlc_minimum_msat: 0,
2326 htlc_maximum_msat: OptionalField::Absent,
2328 fee_proportional_millionths: 0,
2329 excess_data: Vec::new()
2332 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
2334 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
2335 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2336 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2337 short_channel_id: 6,
2340 cltv_expiry_delta: (6 << 4) | 1,
2341 htlc_minimum_msat: 0,
2342 htlc_maximum_msat: OptionalField::Absent,
2344 fee_proportional_millionths: 0,
2345 excess_data: Vec::new()
2347 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2348 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2349 short_channel_id: 6,
2352 cltv_expiry_delta: (6 << 4) | 2,
2353 htlc_minimum_msat: 0,
2354 htlc_maximum_msat: OptionalField::Absent,
2356 fee_proportional_millionths: 0,
2357 excess_data: Vec::new(),
2360 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(11)), 11);
2361 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
2362 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2363 short_channel_id: 11,
2366 cltv_expiry_delta: (11 << 4) | 1,
2367 htlc_minimum_msat: 0,
2368 htlc_maximum_msat: OptionalField::Absent,
2370 fee_proportional_millionths: 0,
2371 excess_data: Vec::new()
2373 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
2374 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2375 short_channel_id: 11,
2378 cltv_expiry_delta: (11 << 4) | 2,
2379 htlc_minimum_msat: 0,
2380 htlc_maximum_msat: OptionalField::Absent,
2382 fee_proportional_millionths: 0,
2383 excess_data: Vec::new()
2386 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(5)), 0);
2388 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
2390 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[5], ChannelFeatures::from_le_bytes(id_to_feature_flags(7)), 7);
2391 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2392 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2393 short_channel_id: 7,
2396 cltv_expiry_delta: (7 << 4) | 1,
2397 htlc_minimum_msat: 0,
2398 htlc_maximum_msat: OptionalField::Absent,
2400 fee_proportional_millionths: 1000000,
2401 excess_data: Vec::new()
2403 update_channel(&gossip_sync, &secp_ctx, &privkeys[5], UnsignedChannelUpdate {
2404 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2405 short_channel_id: 7,
2408 cltv_expiry_delta: (7 << 4) | 2,
2409 htlc_minimum_msat: 0,
2410 htlc_maximum_msat: OptionalField::Absent,
2412 fee_proportional_millionths: 0,
2413 excess_data: Vec::new()
2416 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[5], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
2418 (secp_ctx, network_graph, gossip_sync, chain_monitor, logger)
2422 fn simple_route_test() {
2423 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2424 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2425 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2426 let scorer = test_utils::TestScorer::with_penalty(0);
2427 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2428 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2430 // Simple route to 2 via 1
2432 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) {
2433 assert_eq!(err, "Cannot send a payment of 0 msat");
2434 } else { panic!(); }
2436 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2437 assert_eq!(route.paths[0].len(), 2);
2439 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2440 assert_eq!(route.paths[0][0].short_channel_id, 2);
2441 assert_eq!(route.paths[0][0].fee_msat, 100);
2442 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2443 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2444 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2446 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2447 assert_eq!(route.paths[0][1].short_channel_id, 4);
2448 assert_eq!(route.paths[0][1].fee_msat, 100);
2449 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2450 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2451 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2455 fn invalid_first_hop_test() {
2456 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2457 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2458 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2459 let scorer = test_utils::TestScorer::with_penalty(0);
2460 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2461 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2463 // Simple route to 2 via 1
2465 let our_chans = vec![get_channel_details(Some(2), our_id, InitFeatures::from_le_bytes(vec![0b11]), 100000)];
2467 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) =
2468 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) {
2469 assert_eq!(err, "First hop cannot have our_node_pubkey as a destination.");
2470 } else { panic!(); }
2472 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2473 assert_eq!(route.paths[0].len(), 2);
2477 fn htlc_minimum_test() {
2478 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2479 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2480 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2481 let scorer = test_utils::TestScorer::with_penalty(0);
2482 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2483 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2485 // Simple route to 2 via 1
2487 // Disable other paths
2488 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2489 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2490 short_channel_id: 12,
2492 flags: 2, // to disable
2493 cltv_expiry_delta: 0,
2494 htlc_minimum_msat: 0,
2495 htlc_maximum_msat: OptionalField::Absent,
2497 fee_proportional_millionths: 0,
2498 excess_data: Vec::new()
2500 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
2501 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2502 short_channel_id: 3,
2504 flags: 2, // to disable
2505 cltv_expiry_delta: 0,
2506 htlc_minimum_msat: 0,
2507 htlc_maximum_msat: OptionalField::Absent,
2509 fee_proportional_millionths: 0,
2510 excess_data: Vec::new()
2512 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2513 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2514 short_channel_id: 13,
2516 flags: 2, // to disable
2517 cltv_expiry_delta: 0,
2518 htlc_minimum_msat: 0,
2519 htlc_maximum_msat: OptionalField::Absent,
2521 fee_proportional_millionths: 0,
2522 excess_data: Vec::new()
2524 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2525 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2526 short_channel_id: 6,
2528 flags: 2, // to disable
2529 cltv_expiry_delta: 0,
2530 htlc_minimum_msat: 0,
2531 htlc_maximum_msat: OptionalField::Absent,
2533 fee_proportional_millionths: 0,
2534 excess_data: Vec::new()
2536 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
2537 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2538 short_channel_id: 7,
2540 flags: 2, // to disable
2541 cltv_expiry_delta: 0,
2542 htlc_minimum_msat: 0,
2543 htlc_maximum_msat: OptionalField::Absent,
2545 fee_proportional_millionths: 0,
2546 excess_data: Vec::new()
2549 // Check against amount_to_transfer_over_msat.
2550 // Set minimal HTLC of 200_000_000 msat.
2551 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2552 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2553 short_channel_id: 2,
2556 cltv_expiry_delta: 0,
2557 htlc_minimum_msat: 200_000_000,
2558 htlc_maximum_msat: OptionalField::Absent,
2560 fee_proportional_millionths: 0,
2561 excess_data: Vec::new()
2564 // Second hop only allows to forward 199_999_999 at most, thus not allowing the first hop to
2566 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2567 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2568 short_channel_id: 4,
2571 cltv_expiry_delta: 0,
2572 htlc_minimum_msat: 0,
2573 htlc_maximum_msat: OptionalField::Present(199_999_999),
2575 fee_proportional_millionths: 0,
2576 excess_data: Vec::new()
2579 // Not possible to send 199_999_999, because the minimum on channel=2 is 200_000_000.
2580 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) {
2581 assert_eq!(err, "Failed to find a path to the given destination");
2582 } else { panic!(); }
2584 // Lift the restriction on the first hop.
2585 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2586 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2587 short_channel_id: 2,
2590 cltv_expiry_delta: 0,
2591 htlc_minimum_msat: 0,
2592 htlc_maximum_msat: OptionalField::Absent,
2594 fee_proportional_millionths: 0,
2595 excess_data: Vec::new()
2598 // A payment above the minimum should pass
2599 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();
2600 assert_eq!(route.paths[0].len(), 2);
2604 fn htlc_minimum_overpay_test() {
2605 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2606 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2607 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
2608 let scorer = test_utils::TestScorer::with_penalty(0);
2609 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2610 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2612 // A route to node#2 via two paths.
2613 // One path allows transferring 35-40 sats, another one also allows 35-40 sats.
2614 // Thus, they can't send 60 without overpaying.
2615 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2616 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2617 short_channel_id: 2,
2620 cltv_expiry_delta: 0,
2621 htlc_minimum_msat: 35_000,
2622 htlc_maximum_msat: OptionalField::Present(40_000),
2624 fee_proportional_millionths: 0,
2625 excess_data: Vec::new()
2627 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2628 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2629 short_channel_id: 12,
2632 cltv_expiry_delta: 0,
2633 htlc_minimum_msat: 35_000,
2634 htlc_maximum_msat: OptionalField::Present(40_000),
2636 fee_proportional_millionths: 0,
2637 excess_data: Vec::new()
2641 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
2642 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2643 short_channel_id: 13,
2646 cltv_expiry_delta: 0,
2647 htlc_minimum_msat: 0,
2648 htlc_maximum_msat: OptionalField::Absent,
2650 fee_proportional_millionths: 0,
2651 excess_data: Vec::new()
2653 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2654 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2655 short_channel_id: 4,
2658 cltv_expiry_delta: 0,
2659 htlc_minimum_msat: 0,
2660 htlc_maximum_msat: OptionalField::Absent,
2662 fee_proportional_millionths: 0,
2663 excess_data: Vec::new()
2666 // Disable other paths
2667 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2668 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2669 short_channel_id: 1,
2671 flags: 2, // to disable
2672 cltv_expiry_delta: 0,
2673 htlc_minimum_msat: 0,
2674 htlc_maximum_msat: OptionalField::Absent,
2676 fee_proportional_millionths: 0,
2677 excess_data: Vec::new()
2680 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2681 // Overpay fees to hit htlc_minimum_msat.
2682 let overpaid_fees = route.paths[0][0].fee_msat + route.paths[1][0].fee_msat;
2683 // TODO: this could be better balanced to overpay 10k and not 15k.
2684 assert_eq!(overpaid_fees, 15_000);
2686 // Now, test that if there are 2 paths, a "cheaper" by fee path wouldn't be prioritized
2687 // while taking even more fee to match htlc_minimum_msat.
2688 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2689 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2690 short_channel_id: 12,
2693 cltv_expiry_delta: 0,
2694 htlc_minimum_msat: 65_000,
2695 htlc_maximum_msat: OptionalField::Present(80_000),
2697 fee_proportional_millionths: 0,
2698 excess_data: Vec::new()
2700 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2701 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2702 short_channel_id: 2,
2705 cltv_expiry_delta: 0,
2706 htlc_minimum_msat: 0,
2707 htlc_maximum_msat: OptionalField::Absent,
2709 fee_proportional_millionths: 0,
2710 excess_data: Vec::new()
2712 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2713 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2714 short_channel_id: 4,
2717 cltv_expiry_delta: 0,
2718 htlc_minimum_msat: 0,
2719 htlc_maximum_msat: OptionalField::Absent,
2721 fee_proportional_millionths: 100_000,
2722 excess_data: Vec::new()
2725 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2726 // Fine to overpay for htlc_minimum_msat if it allows us to save fee.
2727 assert_eq!(route.paths.len(), 1);
2728 assert_eq!(route.paths[0][0].short_channel_id, 12);
2729 let fees = route.paths[0][0].fee_msat;
2730 assert_eq!(fees, 5_000);
2732 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2733 // Not fine to overpay for htlc_minimum_msat if it requires paying more than fee on
2734 // the other channel.
2735 assert_eq!(route.paths.len(), 1);
2736 assert_eq!(route.paths[0][0].short_channel_id, 2);
2737 let fees = route.paths[0][0].fee_msat;
2738 assert_eq!(fees, 5_000);
2742 fn disable_channels_test() {
2743 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2744 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2745 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2746 let scorer = test_utils::TestScorer::with_penalty(0);
2747 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2748 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2750 // // Disable channels 4 and 12 by flags=2
2751 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
2752 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2753 short_channel_id: 4,
2755 flags: 2, // to disable
2756 cltv_expiry_delta: 0,
2757 htlc_minimum_msat: 0,
2758 htlc_maximum_msat: OptionalField::Absent,
2760 fee_proportional_millionths: 0,
2761 excess_data: Vec::new()
2763 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
2764 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
2765 short_channel_id: 12,
2767 flags: 2, // to disable
2768 cltv_expiry_delta: 0,
2769 htlc_minimum_msat: 0,
2770 htlc_maximum_msat: OptionalField::Absent,
2772 fee_proportional_millionths: 0,
2773 excess_data: Vec::new()
2776 // If all the channels require some features we don't understand, route should fail
2777 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) {
2778 assert_eq!(err, "Failed to find a path to the given destination");
2779 } else { panic!(); }
2781 // If we specify a channel to node7, that overrides our local channel view and that gets used
2782 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2783 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();
2784 assert_eq!(route.paths[0].len(), 2);
2786 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2787 assert_eq!(route.paths[0][0].short_channel_id, 42);
2788 assert_eq!(route.paths[0][0].fee_msat, 200);
2789 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2790 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2791 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2793 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2794 assert_eq!(route.paths[0][1].short_channel_id, 13);
2795 assert_eq!(route.paths[0][1].fee_msat, 100);
2796 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2797 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2798 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2802 fn disable_node_test() {
2803 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
2804 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
2805 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2806 let scorer = test_utils::TestScorer::with_penalty(0);
2807 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2808 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2810 // Disable nodes 1, 2, and 8 by requiring unknown feature bits
2811 let mut unknown_features = NodeFeatures::known();
2812 unknown_features.set_unknown_feature_required();
2813 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[0], unknown_features.clone(), 1);
2814 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], unknown_features.clone(), 1);
2815 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[7], unknown_features.clone(), 1);
2817 // If all nodes require some features we don't understand, route should fail
2818 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) {
2819 assert_eq!(err, "Failed to find a path to the given destination");
2820 } else { panic!(); }
2822 // If we specify a channel to node7, that overrides our local channel view and that gets used
2823 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2824 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();
2825 assert_eq!(route.paths[0].len(), 2);
2827 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2828 assert_eq!(route.paths[0][0].short_channel_id, 42);
2829 assert_eq!(route.paths[0][0].fee_msat, 200);
2830 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2831 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]); // it should also override our view of their features
2832 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2834 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2835 assert_eq!(route.paths[0][1].short_channel_id, 13);
2836 assert_eq!(route.paths[0][1].fee_msat, 100);
2837 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2838 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2839 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2841 // Note that we don't test disabling node 3 and failing to route to it, as we (somewhat
2842 // naively) assume that the user checked the feature bits on the invoice, which override
2843 // the node_announcement.
2847 fn our_chans_test() {
2848 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2849 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2850 let scorer = test_utils::TestScorer::with_penalty(0);
2851 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2852 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2854 // Route to 1 via 2 and 3 because our channel to 1 is disabled
2855 let payment_params = PaymentParameters::from_node_id(nodes[0]);
2856 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
2857 assert_eq!(route.paths[0].len(), 3);
2859 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
2860 assert_eq!(route.paths[0][0].short_channel_id, 2);
2861 assert_eq!(route.paths[0][0].fee_msat, 200);
2862 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
2863 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
2864 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
2866 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2867 assert_eq!(route.paths[0][1].short_channel_id, 4);
2868 assert_eq!(route.paths[0][1].fee_msat, 100);
2869 assert_eq!(route.paths[0][1].cltv_expiry_delta, (3 << 4) | 2);
2870 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2871 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
2873 assert_eq!(route.paths[0][2].pubkey, nodes[0]);
2874 assert_eq!(route.paths[0][2].short_channel_id, 3);
2875 assert_eq!(route.paths[0][2].fee_msat, 100);
2876 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
2877 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(1));
2878 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(3));
2880 // If we specify a channel to node7, that overrides our local channel view and that gets used
2881 let payment_params = PaymentParameters::from_node_id(nodes[2]);
2882 let our_chans = vec![get_channel_details(Some(42), nodes[7].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
2883 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();
2884 assert_eq!(route.paths[0].len(), 2);
2886 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
2887 assert_eq!(route.paths[0][0].short_channel_id, 42);
2888 assert_eq!(route.paths[0][0].fee_msat, 200);
2889 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
2890 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
2891 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
2893 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
2894 assert_eq!(route.paths[0][1].short_channel_id, 13);
2895 assert_eq!(route.paths[0][1].fee_msat, 100);
2896 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
2897 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
2898 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
2901 fn last_hops(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2902 let zero_fees = RoutingFees {
2904 proportional_millionths: 0,
2906 vec![RouteHint(vec![RouteHintHop {
2907 src_node_id: nodes[3],
2908 short_channel_id: 8,
2910 cltv_expiry_delta: (8 << 4) | 1,
2911 htlc_minimum_msat: None,
2912 htlc_maximum_msat: None,
2914 ]), RouteHint(vec![RouteHintHop {
2915 src_node_id: nodes[4],
2916 short_channel_id: 9,
2919 proportional_millionths: 0,
2921 cltv_expiry_delta: (9 << 4) | 1,
2922 htlc_minimum_msat: None,
2923 htlc_maximum_msat: None,
2924 }]), RouteHint(vec![RouteHintHop {
2925 src_node_id: nodes[5],
2926 short_channel_id: 10,
2928 cltv_expiry_delta: (10 << 4) | 1,
2929 htlc_minimum_msat: None,
2930 htlc_maximum_msat: None,
2934 fn last_hops_multi_private_channels(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
2935 let zero_fees = RoutingFees {
2937 proportional_millionths: 0,
2939 vec![RouteHint(vec![RouteHintHop {
2940 src_node_id: nodes[2],
2941 short_channel_id: 5,
2944 proportional_millionths: 0,
2946 cltv_expiry_delta: (5 << 4) | 1,
2947 htlc_minimum_msat: None,
2948 htlc_maximum_msat: None,
2950 src_node_id: nodes[3],
2951 short_channel_id: 8,
2953 cltv_expiry_delta: (8 << 4) | 1,
2954 htlc_minimum_msat: None,
2955 htlc_maximum_msat: None,
2957 ]), RouteHint(vec![RouteHintHop {
2958 src_node_id: nodes[4],
2959 short_channel_id: 9,
2962 proportional_millionths: 0,
2964 cltv_expiry_delta: (9 << 4) | 1,
2965 htlc_minimum_msat: None,
2966 htlc_maximum_msat: None,
2967 }]), RouteHint(vec![RouteHintHop {
2968 src_node_id: nodes[5],
2969 short_channel_id: 10,
2971 cltv_expiry_delta: (10 << 4) | 1,
2972 htlc_minimum_msat: None,
2973 htlc_maximum_msat: None,
2978 fn partial_route_hint_test() {
2979 let (secp_ctx, network_graph, _, _, logger) = build_graph();
2980 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
2981 let scorer = test_utils::TestScorer::with_penalty(0);
2982 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
2983 let random_seed_bytes = keys_manager.get_secure_random_bytes();
2985 // Simple test across 2, 3, 5, and 4 via a last_hop channel
2986 // Tests the behaviour when the RouteHint contains a suboptimal hop.
2987 // RouteHint may be partially used by the algo to build the best path.
2989 // First check that last hop can't have its source as the payee.
2990 let invalid_last_hop = RouteHint(vec![RouteHintHop {
2991 src_node_id: nodes[6],
2992 short_channel_id: 8,
2995 proportional_millionths: 0,
2997 cltv_expiry_delta: (8 << 4) | 1,
2998 htlc_minimum_msat: None,
2999 htlc_maximum_msat: None,
3002 let mut invalid_last_hops = last_hops_multi_private_channels(&nodes);
3003 invalid_last_hops.push(invalid_last_hop);
3005 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(invalid_last_hops);
3006 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) {
3007 assert_eq!(err, "Route hint cannot have the payee as the source.");
3008 } else { panic!(); }
3011 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_multi_private_channels(&nodes));
3012 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3013 assert_eq!(route.paths[0].len(), 5);
3015 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3016 assert_eq!(route.paths[0][0].short_channel_id, 2);
3017 assert_eq!(route.paths[0][0].fee_msat, 100);
3018 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3019 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3020 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3022 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3023 assert_eq!(route.paths[0][1].short_channel_id, 4);
3024 assert_eq!(route.paths[0][1].fee_msat, 0);
3025 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3026 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3027 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3029 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3030 assert_eq!(route.paths[0][2].short_channel_id, 6);
3031 assert_eq!(route.paths[0][2].fee_msat, 0);
3032 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3033 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3034 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3036 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3037 assert_eq!(route.paths[0][3].short_channel_id, 11);
3038 assert_eq!(route.paths[0][3].fee_msat, 0);
3039 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3040 // If we have a peer in the node map, we'll use their features here since we don't have
3041 // a way of figuring out their features from the invoice:
3042 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3043 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3045 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3046 assert_eq!(route.paths[0][4].short_channel_id, 8);
3047 assert_eq!(route.paths[0][4].fee_msat, 100);
3048 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3049 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3050 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3053 fn empty_last_hop(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3054 let zero_fees = RoutingFees {
3056 proportional_millionths: 0,
3058 vec![RouteHint(vec![RouteHintHop {
3059 src_node_id: nodes[3],
3060 short_channel_id: 8,
3062 cltv_expiry_delta: (8 << 4) | 1,
3063 htlc_minimum_msat: None,
3064 htlc_maximum_msat: None,
3065 }]), RouteHint(vec![
3067 ]), RouteHint(vec![RouteHintHop {
3068 src_node_id: nodes[5],
3069 short_channel_id: 10,
3071 cltv_expiry_delta: (10 << 4) | 1,
3072 htlc_minimum_msat: None,
3073 htlc_maximum_msat: None,
3078 fn ignores_empty_last_hops_test() {
3079 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3080 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3081 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(empty_last_hop(&nodes));
3082 let scorer = test_utils::TestScorer::with_penalty(0);
3083 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3084 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3086 // Test handling of an empty RouteHint passed in Invoice.
3088 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3089 assert_eq!(route.paths[0].len(), 5);
3091 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3092 assert_eq!(route.paths[0][0].short_channel_id, 2);
3093 assert_eq!(route.paths[0][0].fee_msat, 100);
3094 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3095 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3096 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3098 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3099 assert_eq!(route.paths[0][1].short_channel_id, 4);
3100 assert_eq!(route.paths[0][1].fee_msat, 0);
3101 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3102 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3103 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3105 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3106 assert_eq!(route.paths[0][2].short_channel_id, 6);
3107 assert_eq!(route.paths[0][2].fee_msat, 0);
3108 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3109 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3110 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3112 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3113 assert_eq!(route.paths[0][3].short_channel_id, 11);
3114 assert_eq!(route.paths[0][3].fee_msat, 0);
3115 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3116 // If we have a peer in the node map, we'll use their features here since we don't have
3117 // a way of figuring out their features from the invoice:
3118 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3119 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3121 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3122 assert_eq!(route.paths[0][4].short_channel_id, 8);
3123 assert_eq!(route.paths[0][4].fee_msat, 100);
3124 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3125 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3126 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3129 /// Builds a trivial last-hop hint that passes through the two nodes given, with channel 0xff00
3131 fn multi_hop_last_hops_hint(hint_hops: [PublicKey; 2]) -> Vec<RouteHint> {
3132 let zero_fees = RoutingFees {
3134 proportional_millionths: 0,
3136 vec![RouteHint(vec![RouteHintHop {
3137 src_node_id: hint_hops[0],
3138 short_channel_id: 0xff00,
3141 proportional_millionths: 0,
3143 cltv_expiry_delta: (5 << 4) | 1,
3144 htlc_minimum_msat: None,
3145 htlc_maximum_msat: None,
3147 src_node_id: hint_hops[1],
3148 short_channel_id: 0xff01,
3150 cltv_expiry_delta: (8 << 4) | 1,
3151 htlc_minimum_msat: None,
3152 htlc_maximum_msat: None,
3157 fn multi_hint_last_hops_test() {
3158 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3159 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3160 let last_hops = multi_hop_last_hops_hint([nodes[2], nodes[3]]);
3161 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3162 let scorer = test_utils::TestScorer::with_penalty(0);
3163 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3164 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3165 // Test through channels 2, 3, 0xff00, 0xff01.
3166 // Test shows that multiple hop hints are considered.
3168 // Disabling channels 6 & 7 by flags=2
3169 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3170 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3171 short_channel_id: 6,
3173 flags: 2, // to disable
3174 cltv_expiry_delta: 0,
3175 htlc_minimum_msat: 0,
3176 htlc_maximum_msat: OptionalField::Absent,
3178 fee_proportional_millionths: 0,
3179 excess_data: Vec::new()
3181 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3182 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3183 short_channel_id: 7,
3185 flags: 2, // to disable
3186 cltv_expiry_delta: 0,
3187 htlc_minimum_msat: 0,
3188 htlc_maximum_msat: OptionalField::Absent,
3190 fee_proportional_millionths: 0,
3191 excess_data: Vec::new()
3194 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3195 assert_eq!(route.paths[0].len(), 4);
3197 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3198 assert_eq!(route.paths[0][0].short_channel_id, 2);
3199 assert_eq!(route.paths[0][0].fee_msat, 200);
3200 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3201 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3202 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3204 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3205 assert_eq!(route.paths[0][1].short_channel_id, 4);
3206 assert_eq!(route.paths[0][1].fee_msat, 100);
3207 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3208 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3209 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3211 assert_eq!(route.paths[0][2].pubkey, nodes[3]);
3212 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3213 assert_eq!(route.paths[0][2].fee_msat, 0);
3214 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3215 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(4));
3216 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3218 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3219 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3220 assert_eq!(route.paths[0][3].fee_msat, 100);
3221 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3222 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3223 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3227 fn private_multi_hint_last_hops_test() {
3228 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3229 let (_, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3231 let non_announced_privkey = SecretKey::from_slice(&hex::decode(format!("{:02x}", 0xf0).repeat(32)).unwrap()[..]).unwrap();
3232 let non_announced_pubkey = PublicKey::from_secret_key(&secp_ctx, &non_announced_privkey);
3234 let last_hops = multi_hop_last_hops_hint([nodes[2], non_announced_pubkey]);
3235 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3236 let scorer = test_utils::TestScorer::with_penalty(0);
3237 // Test through channels 2, 3, 0xff00, 0xff01.
3238 // Test shows that multiple hop hints are considered.
3240 // Disabling channels 6 & 7 by flags=2
3241 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3242 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3243 short_channel_id: 6,
3245 flags: 2, // to disable
3246 cltv_expiry_delta: 0,
3247 htlc_minimum_msat: 0,
3248 htlc_maximum_msat: OptionalField::Absent,
3250 fee_proportional_millionths: 0,
3251 excess_data: Vec::new()
3253 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3254 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3255 short_channel_id: 7,
3257 flags: 2, // to disable
3258 cltv_expiry_delta: 0,
3259 htlc_minimum_msat: 0,
3260 htlc_maximum_msat: OptionalField::Absent,
3262 fee_proportional_millionths: 0,
3263 excess_data: Vec::new()
3266 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &[42u8; 32]).unwrap();
3267 assert_eq!(route.paths[0].len(), 4);
3269 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3270 assert_eq!(route.paths[0][0].short_channel_id, 2);
3271 assert_eq!(route.paths[0][0].fee_msat, 200);
3272 assert_eq!(route.paths[0][0].cltv_expiry_delta, 65);
3273 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3274 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3276 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3277 assert_eq!(route.paths[0][1].short_channel_id, 4);
3278 assert_eq!(route.paths[0][1].fee_msat, 100);
3279 assert_eq!(route.paths[0][1].cltv_expiry_delta, 81);
3280 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3281 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3283 assert_eq!(route.paths[0][2].pubkey, non_announced_pubkey);
3284 assert_eq!(route.paths[0][2].short_channel_id, last_hops[0].0[0].short_channel_id);
3285 assert_eq!(route.paths[0][2].fee_msat, 0);
3286 assert_eq!(route.paths[0][2].cltv_expiry_delta, 129);
3287 assert_eq!(route.paths[0][2].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3288 assert_eq!(route.paths[0][2].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3290 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3291 assert_eq!(route.paths[0][3].short_channel_id, last_hops[0].0[1].short_channel_id);
3292 assert_eq!(route.paths[0][3].fee_msat, 100);
3293 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3294 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3295 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3298 fn last_hops_with_public_channel(nodes: &Vec<PublicKey>) -> Vec<RouteHint> {
3299 let zero_fees = RoutingFees {
3301 proportional_millionths: 0,
3303 vec![RouteHint(vec![RouteHintHop {
3304 src_node_id: nodes[4],
3305 short_channel_id: 11,
3307 cltv_expiry_delta: (11 << 4) | 1,
3308 htlc_minimum_msat: None,
3309 htlc_maximum_msat: None,
3311 src_node_id: nodes[3],
3312 short_channel_id: 8,
3314 cltv_expiry_delta: (8 << 4) | 1,
3315 htlc_minimum_msat: None,
3316 htlc_maximum_msat: None,
3317 }]), RouteHint(vec![RouteHintHop {
3318 src_node_id: nodes[4],
3319 short_channel_id: 9,
3322 proportional_millionths: 0,
3324 cltv_expiry_delta: (9 << 4) | 1,
3325 htlc_minimum_msat: None,
3326 htlc_maximum_msat: None,
3327 }]), RouteHint(vec![RouteHintHop {
3328 src_node_id: nodes[5],
3329 short_channel_id: 10,
3331 cltv_expiry_delta: (10 << 4) | 1,
3332 htlc_minimum_msat: None,
3333 htlc_maximum_msat: None,
3338 fn last_hops_with_public_channel_test() {
3339 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3340 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3341 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops_with_public_channel(&nodes));
3342 let scorer = test_utils::TestScorer::with_penalty(0);
3343 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3344 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3345 // This test shows that public routes can be present in the invoice
3346 // which would be handled in the same manner.
3348 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3349 assert_eq!(route.paths[0].len(), 5);
3351 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3352 assert_eq!(route.paths[0][0].short_channel_id, 2);
3353 assert_eq!(route.paths[0][0].fee_msat, 100);
3354 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3355 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3356 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3358 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3359 assert_eq!(route.paths[0][1].short_channel_id, 4);
3360 assert_eq!(route.paths[0][1].fee_msat, 0);
3361 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3362 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3363 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3365 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3366 assert_eq!(route.paths[0][2].short_channel_id, 6);
3367 assert_eq!(route.paths[0][2].fee_msat, 0);
3368 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3369 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3370 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3372 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3373 assert_eq!(route.paths[0][3].short_channel_id, 11);
3374 assert_eq!(route.paths[0][3].fee_msat, 0);
3375 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3376 // If we have a peer in the node map, we'll use their features here since we don't have
3377 // a way of figuring out their features from the invoice:
3378 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3379 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3381 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3382 assert_eq!(route.paths[0][4].short_channel_id, 8);
3383 assert_eq!(route.paths[0][4].fee_msat, 100);
3384 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3385 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3386 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3390 fn our_chans_last_hop_connect_test() {
3391 let (secp_ctx, network_graph, _, _, logger) = build_graph();
3392 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
3393 let scorer = test_utils::TestScorer::with_penalty(0);
3394 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3395 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3397 // Simple test with outbound channel to 4 to test that last_hops and first_hops connect
3398 let our_chans = vec![get_channel_details(Some(42), nodes[3].clone(), InitFeatures::from_le_bytes(vec![0b11]), 250_000_000)];
3399 let mut last_hops = last_hops(&nodes);
3400 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops.clone());
3401 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();
3402 assert_eq!(route.paths[0].len(), 2);
3404 assert_eq!(route.paths[0][0].pubkey, nodes[3]);
3405 assert_eq!(route.paths[0][0].short_channel_id, 42);
3406 assert_eq!(route.paths[0][0].fee_msat, 0);
3407 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3408 assert_eq!(route.paths[0][0].node_features.le_flags(), &vec![0b11]);
3409 assert_eq!(route.paths[0][0].channel_features.le_flags(), &Vec::<u8>::new()); // No feature flags will meet the relevant-to-channel conversion
3411 assert_eq!(route.paths[0][1].pubkey, nodes[6]);
3412 assert_eq!(route.paths[0][1].short_channel_id, 8);
3413 assert_eq!(route.paths[0][1].fee_msat, 100);
3414 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3415 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3416 assert_eq!(route.paths[0][1].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3418 last_hops[0].0[0].fees.base_msat = 1000;
3420 // Revert to via 6 as the fee on 8 goes up
3421 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops);
3422 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3423 assert_eq!(route.paths[0].len(), 4);
3425 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3426 assert_eq!(route.paths[0][0].short_channel_id, 2);
3427 assert_eq!(route.paths[0][0].fee_msat, 200); // fee increased as its % of value transferred across node
3428 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3429 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3430 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3432 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3433 assert_eq!(route.paths[0][1].short_channel_id, 4);
3434 assert_eq!(route.paths[0][1].fee_msat, 100);
3435 assert_eq!(route.paths[0][1].cltv_expiry_delta, (7 << 4) | 1);
3436 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3437 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3439 assert_eq!(route.paths[0][2].pubkey, nodes[5]);
3440 assert_eq!(route.paths[0][2].short_channel_id, 7);
3441 assert_eq!(route.paths[0][2].fee_msat, 0);
3442 assert_eq!(route.paths[0][2].cltv_expiry_delta, (10 << 4) | 1);
3443 // If we have a peer in the node map, we'll use their features here since we don't have
3444 // a way of figuring out their features from the invoice:
3445 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
3446 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(7));
3448 assert_eq!(route.paths[0][3].pubkey, nodes[6]);
3449 assert_eq!(route.paths[0][3].short_channel_id, 10);
3450 assert_eq!(route.paths[0][3].fee_msat, 100);
3451 assert_eq!(route.paths[0][3].cltv_expiry_delta, 42);
3452 assert_eq!(route.paths[0][3].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3453 assert_eq!(route.paths[0][3].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3455 // ...but still use 8 for larger payments as 6 has a variable feerate
3456 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 2000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3457 assert_eq!(route.paths[0].len(), 5);
3459 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
3460 assert_eq!(route.paths[0][0].short_channel_id, 2);
3461 assert_eq!(route.paths[0][0].fee_msat, 3000);
3462 assert_eq!(route.paths[0][0].cltv_expiry_delta, (4 << 4) | 1);
3463 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(2));
3464 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(2));
3466 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
3467 assert_eq!(route.paths[0][1].short_channel_id, 4);
3468 assert_eq!(route.paths[0][1].fee_msat, 0);
3469 assert_eq!(route.paths[0][1].cltv_expiry_delta, (6 << 4) | 1);
3470 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
3471 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(4));
3473 assert_eq!(route.paths[0][2].pubkey, nodes[4]);
3474 assert_eq!(route.paths[0][2].short_channel_id, 6);
3475 assert_eq!(route.paths[0][2].fee_msat, 0);
3476 assert_eq!(route.paths[0][2].cltv_expiry_delta, (11 << 4) | 1);
3477 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(5));
3478 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(6));
3480 assert_eq!(route.paths[0][3].pubkey, nodes[3]);
3481 assert_eq!(route.paths[0][3].short_channel_id, 11);
3482 assert_eq!(route.paths[0][3].fee_msat, 1000);
3483 assert_eq!(route.paths[0][3].cltv_expiry_delta, (8 << 4) | 1);
3484 // If we have a peer in the node map, we'll use their features here since we don't have
3485 // a way of figuring out their features from the invoice:
3486 assert_eq!(route.paths[0][3].node_features.le_flags(), &id_to_feature_flags(4));
3487 assert_eq!(route.paths[0][3].channel_features.le_flags(), &id_to_feature_flags(11));
3489 assert_eq!(route.paths[0][4].pubkey, nodes[6]);
3490 assert_eq!(route.paths[0][4].short_channel_id, 8);
3491 assert_eq!(route.paths[0][4].fee_msat, 2000);
3492 assert_eq!(route.paths[0][4].cltv_expiry_delta, 42);
3493 assert_eq!(route.paths[0][4].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3494 assert_eq!(route.paths[0][4].channel_features.le_flags(), &Vec::<u8>::new()); // We can't learn any flags from invoices, sadly
3497 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> {
3498 let source_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 41).repeat(32)).unwrap()[..]).unwrap());
3499 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3500 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3502 // If we specify a channel to a middle hop, that overrides our local channel view and that gets used
3503 let last_hops = RouteHint(vec![RouteHintHop {
3504 src_node_id: middle_node_id,
3505 short_channel_id: 8,
3508 proportional_millionths: last_hop_fee_prop,
3510 cltv_expiry_delta: (8 << 4) | 1,
3511 htlc_minimum_msat: None,
3512 htlc_maximum_msat: last_hop_htlc_max,
3514 let payment_params = PaymentParameters::from_node_id(target_node_id).with_route_hints(vec![last_hops]);
3515 let our_chans = vec![get_channel_details(Some(42), middle_node_id, InitFeatures::from_le_bytes(vec![0b11]), outbound_capacity_msat)];
3516 let scorer = test_utils::TestScorer::with_penalty(0);
3517 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3518 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3519 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
3520 let logger = test_utils::TestLogger::new();
3521 let network_graph = NetworkGraph::new(genesis_hash, &logger);
3522 let route = get_route(&source_node_id, &payment_params, &network_graph.read_only(),
3523 Some(&our_chans.iter().collect::<Vec<_>>()), route_val, 42, &logger, &scorer, &random_seed_bytes);
3528 fn unannounced_path_test() {
3529 // We should be able to send a payment to a destination without any help of a routing graph
3530 // if we have a channel with a common counterparty that appears in the first and last hop
3532 let route = do_unannounced_path_test(None, 1, 2000000, 1000000).unwrap();
3534 let middle_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 42).repeat(32)).unwrap()[..]).unwrap());
3535 let target_node_id = PublicKey::from_secret_key(&Secp256k1::new(), &SecretKey::from_slice(&hex::decode(format!("{:02}", 43).repeat(32)).unwrap()[..]).unwrap());
3536 assert_eq!(route.paths[0].len(), 2);
3538 assert_eq!(route.paths[0][0].pubkey, middle_node_id);
3539 assert_eq!(route.paths[0][0].short_channel_id, 42);
3540 assert_eq!(route.paths[0][0].fee_msat, 1001);
3541 assert_eq!(route.paths[0][0].cltv_expiry_delta, (8 << 4) | 1);
3542 assert_eq!(route.paths[0][0].node_features.le_flags(), &[0b11]);
3543 assert_eq!(route.paths[0][0].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3545 assert_eq!(route.paths[0][1].pubkey, target_node_id);
3546 assert_eq!(route.paths[0][1].short_channel_id, 8);
3547 assert_eq!(route.paths[0][1].fee_msat, 1000000);
3548 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
3549 assert_eq!(route.paths[0][1].node_features.le_flags(), default_node_features().le_flags()); // We dont pass flags in from invoices yet
3550 assert_eq!(route.paths[0][1].channel_features.le_flags(), &[0; 0]); // We can't learn any flags from invoices, sadly
3554 fn overflow_unannounced_path_test_liquidity_underflow() {
3555 // Previously, when we had a last-hop hint connected directly to a first-hop channel, where
3556 // the last-hop had a fee which overflowed a u64, we'd panic.
3557 // This was due to us adding the first-hop from us unconditionally, causing us to think
3558 // we'd built a path (as our node is in the "best candidate" set), when we had not.
3559 // In this test, we previously hit a subtraction underflow due to having less available
3560 // liquidity at the last hop than 0.
3561 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());
3565 fn overflow_unannounced_path_test_feerate_overflow() {
3566 // This tests for the same case as above, except instead of hitting a subtraction
3567 // underflow, we hit a case where the fee charged at a hop overflowed.
3568 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());
3572 fn available_amount_while_routing_test() {
3573 // Tests whether we choose the correct available channel amount while routing.
3575 let (secp_ctx, network_graph, mut gossip_sync, chain_monitor, logger) = build_graph();
3576 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3577 let scorer = test_utils::TestScorer::with_penalty(0);
3578 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3579 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3580 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
3582 // We will use a simple single-path route from
3583 // our node to node2 via node0: channels {1, 3}.
3585 // First disable all other paths.
3586 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3587 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3588 short_channel_id: 2,
3591 cltv_expiry_delta: 0,
3592 htlc_minimum_msat: 0,
3593 htlc_maximum_msat: OptionalField::Present(100_000),
3595 fee_proportional_millionths: 0,
3596 excess_data: Vec::new()
3598 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3599 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3600 short_channel_id: 12,
3603 cltv_expiry_delta: 0,
3604 htlc_minimum_msat: 0,
3605 htlc_maximum_msat: OptionalField::Present(100_000),
3607 fee_proportional_millionths: 0,
3608 excess_data: Vec::new()
3611 // Make the first channel (#1) very permissive,
3612 // and we will be testing all limits on the second channel.
3613 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3614 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3615 short_channel_id: 1,
3618 cltv_expiry_delta: 0,
3619 htlc_minimum_msat: 0,
3620 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3622 fee_proportional_millionths: 0,
3623 excess_data: Vec::new()
3626 // First, let's see if routing works if we have absolutely no idea about the available amount.
3627 // In this case, it should be set to 250_000 sats.
3628 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3629 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3630 short_channel_id: 3,
3633 cltv_expiry_delta: 0,
3634 htlc_minimum_msat: 0,
3635 htlc_maximum_msat: OptionalField::Absent,
3637 fee_proportional_millionths: 0,
3638 excess_data: Vec::new()
3642 // Attempt to route more than available results in a failure.
3643 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3644 &our_id, &payment_params, &network_graph.read_only(), None, 250_000_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3645 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3646 } else { panic!(); }
3650 // Now, attempt to route an exact amount we have should be fine.
3651 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();
3652 assert_eq!(route.paths.len(), 1);
3653 let path = route.paths.last().unwrap();
3654 assert_eq!(path.len(), 2);
3655 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3656 assert_eq!(path.last().unwrap().fee_msat, 250_000_000);
3659 // Check that setting next_outbound_htlc_limit_msat in first_hops limits the channels.
3660 // Disable channel #1 and use another first hop.
3661 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3662 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3663 short_channel_id: 1,
3666 cltv_expiry_delta: 0,
3667 htlc_minimum_msat: 0,
3668 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3670 fee_proportional_millionths: 0,
3671 excess_data: Vec::new()
3674 // Now, limit the first_hop by the next_outbound_htlc_limit_msat of 200_000 sats.
3675 let our_chans = vec![get_channel_details(Some(42), nodes[0].clone(), InitFeatures::from_le_bytes(vec![0b11]), 200_000_000)];
3678 // Attempt to route more than available results in a failure.
3679 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3680 &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) {
3681 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3682 } else { panic!(); }
3686 // Now, attempt to route an exact amount we have should be fine.
3687 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();
3688 assert_eq!(route.paths.len(), 1);
3689 let path = route.paths.last().unwrap();
3690 assert_eq!(path.len(), 2);
3691 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3692 assert_eq!(path.last().unwrap().fee_msat, 200_000_000);
3695 // Enable channel #1 back.
3696 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3697 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3698 short_channel_id: 1,
3701 cltv_expiry_delta: 0,
3702 htlc_minimum_msat: 0,
3703 htlc_maximum_msat: OptionalField::Present(1_000_000_000),
3705 fee_proportional_millionths: 0,
3706 excess_data: Vec::new()
3710 // Now let's see if routing works if we know only htlc_maximum_msat.
3711 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3712 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3713 short_channel_id: 3,
3716 cltv_expiry_delta: 0,
3717 htlc_minimum_msat: 0,
3718 htlc_maximum_msat: OptionalField::Present(15_000),
3720 fee_proportional_millionths: 0,
3721 excess_data: Vec::new()
3725 // Attempt to route more than available results in a failure.
3726 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3727 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3728 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3729 } else { panic!(); }
3733 // Now, attempt to route an exact amount we have should be fine.
3734 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3735 assert_eq!(route.paths.len(), 1);
3736 let path = route.paths.last().unwrap();
3737 assert_eq!(path.len(), 2);
3738 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3739 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3742 // Now let's see if routing works if we know only capacity from the UTXO.
3744 // We can't change UTXO capacity on the fly, so we'll disable
3745 // the existing channel and add another one with the capacity we need.
3746 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3747 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3748 short_channel_id: 3,
3751 cltv_expiry_delta: 0,
3752 htlc_minimum_msat: 0,
3753 htlc_maximum_msat: OptionalField::Absent,
3755 fee_proportional_millionths: 0,
3756 excess_data: Vec::new()
3759 let good_script = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2)
3760 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[0]).serialize())
3761 .push_slice(&PublicKey::from_secret_key(&secp_ctx, &privkeys[2]).serialize())
3762 .push_opcode(opcodes::all::OP_PUSHNUM_2)
3763 .push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script().to_v0_p2wsh();
3765 *chain_monitor.utxo_ret.lock().unwrap() = Ok(TxOut { value: 15, script_pubkey: good_script.clone() });
3766 gossip_sync.add_chain_access(Some(chain_monitor));
3768 add_channel(&gossip_sync, &secp_ctx, &privkeys[0], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 333);
3769 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3770 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3771 short_channel_id: 333,
3774 cltv_expiry_delta: (3 << 4) | 1,
3775 htlc_minimum_msat: 0,
3776 htlc_maximum_msat: OptionalField::Absent,
3778 fee_proportional_millionths: 0,
3779 excess_data: Vec::new()
3781 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3782 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3783 short_channel_id: 333,
3786 cltv_expiry_delta: (3 << 4) | 2,
3787 htlc_minimum_msat: 0,
3788 htlc_maximum_msat: OptionalField::Absent,
3790 fee_proportional_millionths: 0,
3791 excess_data: Vec::new()
3795 // Attempt to route more than available results in a failure.
3796 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3797 &our_id, &payment_params, &network_graph.read_only(), None, 15_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3798 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3799 } else { panic!(); }
3803 // Now, attempt to route an exact amount we have should be fine.
3804 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 15_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3805 assert_eq!(route.paths.len(), 1);
3806 let path = route.paths.last().unwrap();
3807 assert_eq!(path.len(), 2);
3808 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3809 assert_eq!(path.last().unwrap().fee_msat, 15_000);
3812 // Now let's see if routing chooses htlc_maximum_msat over UTXO capacity.
3813 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3814 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3815 short_channel_id: 333,
3818 cltv_expiry_delta: 0,
3819 htlc_minimum_msat: 0,
3820 htlc_maximum_msat: OptionalField::Present(10_000),
3822 fee_proportional_millionths: 0,
3823 excess_data: Vec::new()
3827 // Attempt to route more than available results in a failure.
3828 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3829 &our_id, &payment_params, &network_graph.read_only(), None, 10_001, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3830 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3831 } else { panic!(); }
3835 // Now, attempt to route an exact amount we have should be fine.
3836 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3837 assert_eq!(route.paths.len(), 1);
3838 let path = route.paths.last().unwrap();
3839 assert_eq!(path.len(), 2);
3840 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
3841 assert_eq!(path.last().unwrap().fee_msat, 10_000);
3846 fn available_liquidity_last_hop_test() {
3847 // Check that available liquidity properly limits the path even when only
3848 // one of the latter hops is limited.
3849 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3850 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3851 let scorer = test_utils::TestScorer::with_penalty(0);
3852 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3853 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3854 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
3856 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
3857 // {12, 13, 11} have the capacities of 100, {6} has a capacity of 50.
3858 // Total capacity: 50 sats.
3860 // Disable other potential paths.
3861 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3862 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3863 short_channel_id: 2,
3866 cltv_expiry_delta: 0,
3867 htlc_minimum_msat: 0,
3868 htlc_maximum_msat: OptionalField::Present(100_000),
3870 fee_proportional_millionths: 0,
3871 excess_data: Vec::new()
3873 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3874 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3875 short_channel_id: 7,
3878 cltv_expiry_delta: 0,
3879 htlc_minimum_msat: 0,
3880 htlc_maximum_msat: OptionalField::Present(100_000),
3882 fee_proportional_millionths: 0,
3883 excess_data: Vec::new()
3888 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3889 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3890 short_channel_id: 12,
3893 cltv_expiry_delta: 0,
3894 htlc_minimum_msat: 0,
3895 htlc_maximum_msat: OptionalField::Present(100_000),
3897 fee_proportional_millionths: 0,
3898 excess_data: Vec::new()
3900 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
3901 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3902 short_channel_id: 13,
3905 cltv_expiry_delta: 0,
3906 htlc_minimum_msat: 0,
3907 htlc_maximum_msat: OptionalField::Present(100_000),
3909 fee_proportional_millionths: 0,
3910 excess_data: Vec::new()
3913 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
3914 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3915 short_channel_id: 6,
3918 cltv_expiry_delta: 0,
3919 htlc_minimum_msat: 0,
3920 htlc_maximum_msat: OptionalField::Present(50_000),
3922 fee_proportional_millionths: 0,
3923 excess_data: Vec::new()
3925 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
3926 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3927 short_channel_id: 11,
3930 cltv_expiry_delta: 0,
3931 htlc_minimum_msat: 0,
3932 htlc_maximum_msat: OptionalField::Present(100_000),
3934 fee_proportional_millionths: 0,
3935 excess_data: Vec::new()
3938 // Attempt to route more than available results in a failure.
3939 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
3940 &our_id, &payment_params, &network_graph.read_only(), None, 60_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
3941 assert_eq!(err, "Failed to find a sufficient route to the given destination");
3942 } else { panic!(); }
3946 // Now, attempt to route 49 sats (just a bit below the capacity).
3947 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 49_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3948 assert_eq!(route.paths.len(), 1);
3949 let mut total_amount_paid_msat = 0;
3950 for path in &route.paths {
3951 assert_eq!(path.len(), 4);
3952 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3953 total_amount_paid_msat += path.last().unwrap().fee_msat;
3955 assert_eq!(total_amount_paid_msat, 49_000);
3959 // Attempt to route an exact amount is also fine
3960 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
3961 assert_eq!(route.paths.len(), 1);
3962 let mut total_amount_paid_msat = 0;
3963 for path in &route.paths {
3964 assert_eq!(path.len(), 4);
3965 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
3966 total_amount_paid_msat += path.last().unwrap().fee_msat;
3968 assert_eq!(total_amount_paid_msat, 50_000);
3973 fn ignore_fee_first_hop_test() {
3974 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
3975 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
3976 let scorer = test_utils::TestScorer::with_penalty(0);
3977 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
3978 let random_seed_bytes = keys_manager.get_secure_random_bytes();
3979 let payment_params = PaymentParameters::from_node_id(nodes[2]);
3981 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
3982 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
3983 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3984 short_channel_id: 1,
3987 cltv_expiry_delta: 0,
3988 htlc_minimum_msat: 0,
3989 htlc_maximum_msat: OptionalField::Present(100_000),
3990 fee_base_msat: 1_000_000,
3991 fee_proportional_millionths: 0,
3992 excess_data: Vec::new()
3994 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
3995 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
3996 short_channel_id: 3,
3999 cltv_expiry_delta: 0,
4000 htlc_minimum_msat: 0,
4001 htlc_maximum_msat: OptionalField::Present(50_000),
4003 fee_proportional_millionths: 0,
4004 excess_data: Vec::new()
4008 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 50_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4009 assert_eq!(route.paths.len(), 1);
4010 let mut total_amount_paid_msat = 0;
4011 for path in &route.paths {
4012 assert_eq!(path.len(), 2);
4013 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4014 total_amount_paid_msat += path.last().unwrap().fee_msat;
4016 assert_eq!(total_amount_paid_msat, 50_000);
4021 fn simple_mpp_route_test() {
4022 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4023 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4024 let scorer = test_utils::TestScorer::with_penalty(0);
4025 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4026 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4027 let payment_params = PaymentParameters::from_node_id(nodes[2])
4028 .with_features(InvoiceFeatures::known());
4030 // We need a route consisting of 3 paths:
4031 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4032 // To achieve this, the amount being transferred should be around
4033 // the total capacity of these 3 paths.
4035 // First, we set limits on these (previously unlimited) channels.
4036 // Their aggregate capacity will be 50 + 60 + 180 = 290 sats.
4038 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50).
4039 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4040 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4041 short_channel_id: 1,
4044 cltv_expiry_delta: 0,
4045 htlc_minimum_msat: 0,
4046 htlc_maximum_msat: OptionalField::Present(100_000),
4048 fee_proportional_millionths: 0,
4049 excess_data: Vec::new()
4051 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4052 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4053 short_channel_id: 3,
4056 cltv_expiry_delta: 0,
4057 htlc_minimum_msat: 0,
4058 htlc_maximum_msat: OptionalField::Present(50_000),
4060 fee_proportional_millionths: 0,
4061 excess_data: Vec::new()
4064 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats
4065 // (total limit 60).
4066 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4067 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4068 short_channel_id: 12,
4071 cltv_expiry_delta: 0,
4072 htlc_minimum_msat: 0,
4073 htlc_maximum_msat: OptionalField::Present(60_000),
4075 fee_proportional_millionths: 0,
4076 excess_data: Vec::new()
4078 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4079 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4080 short_channel_id: 13,
4083 cltv_expiry_delta: 0,
4084 htlc_minimum_msat: 0,
4085 htlc_maximum_msat: OptionalField::Present(60_000),
4087 fee_proportional_millionths: 0,
4088 excess_data: Vec::new()
4091 // Path via node1 is channels {2, 4}. Limit them to 200 and 180 sats
4092 // (total capacity 180 sats).
4093 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4094 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4095 short_channel_id: 2,
4098 cltv_expiry_delta: 0,
4099 htlc_minimum_msat: 0,
4100 htlc_maximum_msat: OptionalField::Present(200_000),
4102 fee_proportional_millionths: 0,
4103 excess_data: Vec::new()
4105 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4106 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4107 short_channel_id: 4,
4110 cltv_expiry_delta: 0,
4111 htlc_minimum_msat: 0,
4112 htlc_maximum_msat: OptionalField::Present(180_000),
4114 fee_proportional_millionths: 0,
4115 excess_data: Vec::new()
4119 // Attempt to route more than available results in a failure.
4120 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4121 &our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42,
4122 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4123 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4124 } else { panic!(); }
4128 // Attempt to route while setting max_path_count to 0 results in a failure.
4129 let zero_payment_params = payment_params.clone().with_max_path_count(0);
4130 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4131 &our_id, &zero_payment_params, &network_graph.read_only(), None, 100, 42,
4132 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4133 assert_eq!(err, "Can't find a route with no paths allowed.");
4134 } else { panic!(); }
4138 // Attempt to route while setting max_path_count to 3 results in a failure.
4139 // This is the case because the minimal_value_contribution_msat would require each path
4140 // to account for 1/3 of the total value, which is violated by 2 out of 3 paths.
4141 let fail_payment_params = payment_params.clone().with_max_path_count(3);
4142 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4143 &our_id, &fail_payment_params, &network_graph.read_only(), None, 250_000, 42,
4144 Arc::clone(&logger), &scorer, &random_seed_bytes) {
4145 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4146 } else { panic!(); }
4150 // Now, attempt to route 250 sats (just a bit below the capacity).
4151 // Our algorithm should provide us with these 3 paths.
4152 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4153 250_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4154 assert_eq!(route.paths.len(), 3);
4155 let mut total_amount_paid_msat = 0;
4156 for path in &route.paths {
4157 assert_eq!(path.len(), 2);
4158 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4159 total_amount_paid_msat += path.last().unwrap().fee_msat;
4161 assert_eq!(total_amount_paid_msat, 250_000);
4165 // Attempt to route an exact amount is also fine
4166 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None,
4167 290_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4168 assert_eq!(route.paths.len(), 3);
4169 let mut total_amount_paid_msat = 0;
4170 for path in &route.paths {
4171 assert_eq!(path.len(), 2);
4172 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4173 total_amount_paid_msat += path.last().unwrap().fee_msat;
4175 assert_eq!(total_amount_paid_msat, 290_000);
4180 fn long_mpp_route_test() {
4181 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4182 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4183 let scorer = test_utils::TestScorer::with_penalty(0);
4184 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4185 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4186 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4188 // We need a route consisting of 3 paths:
4189 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4190 // Note that these paths overlap (channels 5, 12, 13).
4191 // We will route 300 sats.
4192 // Each path will have 100 sats capacity, those channels which
4193 // are used twice will have 200 sats capacity.
4195 // Disable other potential paths.
4196 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4197 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4198 short_channel_id: 2,
4201 cltv_expiry_delta: 0,
4202 htlc_minimum_msat: 0,
4203 htlc_maximum_msat: OptionalField::Present(100_000),
4205 fee_proportional_millionths: 0,
4206 excess_data: Vec::new()
4208 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4209 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4210 short_channel_id: 7,
4213 cltv_expiry_delta: 0,
4214 htlc_minimum_msat: 0,
4215 htlc_maximum_msat: OptionalField::Present(100_000),
4217 fee_proportional_millionths: 0,
4218 excess_data: Vec::new()
4221 // Path via {node0, node2} is channels {1, 3, 5}.
4222 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4223 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4224 short_channel_id: 1,
4227 cltv_expiry_delta: 0,
4228 htlc_minimum_msat: 0,
4229 htlc_maximum_msat: OptionalField::Present(100_000),
4231 fee_proportional_millionths: 0,
4232 excess_data: Vec::new()
4234 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4235 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4236 short_channel_id: 3,
4239 cltv_expiry_delta: 0,
4240 htlc_minimum_msat: 0,
4241 htlc_maximum_msat: OptionalField::Present(100_000),
4243 fee_proportional_millionths: 0,
4244 excess_data: Vec::new()
4247 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4248 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4249 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4250 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4251 short_channel_id: 5,
4254 cltv_expiry_delta: 0,
4255 htlc_minimum_msat: 0,
4256 htlc_maximum_msat: OptionalField::Present(200_000),
4258 fee_proportional_millionths: 0,
4259 excess_data: Vec::new()
4262 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4263 // Add 100 sats to the capacities of {12, 13}, because these channels
4264 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4265 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4266 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4267 short_channel_id: 12,
4270 cltv_expiry_delta: 0,
4271 htlc_minimum_msat: 0,
4272 htlc_maximum_msat: OptionalField::Present(200_000),
4274 fee_proportional_millionths: 0,
4275 excess_data: Vec::new()
4277 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4278 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4279 short_channel_id: 13,
4282 cltv_expiry_delta: 0,
4283 htlc_minimum_msat: 0,
4284 htlc_maximum_msat: OptionalField::Present(200_000),
4286 fee_proportional_millionths: 0,
4287 excess_data: Vec::new()
4290 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4291 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4292 short_channel_id: 6,
4295 cltv_expiry_delta: 0,
4296 htlc_minimum_msat: 0,
4297 htlc_maximum_msat: OptionalField::Present(100_000),
4299 fee_proportional_millionths: 0,
4300 excess_data: Vec::new()
4302 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4303 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4304 short_channel_id: 11,
4307 cltv_expiry_delta: 0,
4308 htlc_minimum_msat: 0,
4309 htlc_maximum_msat: OptionalField::Present(100_000),
4311 fee_proportional_millionths: 0,
4312 excess_data: Vec::new()
4315 // Path via {node7, node2} is channels {12, 13, 5}.
4316 // We already limited them to 200 sats (they are used twice for 100 sats).
4317 // Nothing to do here.
4320 // Attempt to route more than available results in a failure.
4321 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4322 &our_id, &payment_params, &network_graph.read_only(), None, 350_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4323 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4324 } else { panic!(); }
4328 // Now, attempt to route 300 sats (exact amount we can route).
4329 // Our algorithm should provide us with these 3 paths, 100 sats each.
4330 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 300_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4331 assert_eq!(route.paths.len(), 3);
4333 let mut total_amount_paid_msat = 0;
4334 for path in &route.paths {
4335 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4336 total_amount_paid_msat += path.last().unwrap().fee_msat;
4338 assert_eq!(total_amount_paid_msat, 300_000);
4344 fn mpp_cheaper_route_test() {
4345 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4346 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4347 let scorer = test_utils::TestScorer::with_penalty(0);
4348 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4349 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4350 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4352 // This test checks that if we have two cheaper paths and one more expensive path,
4353 // so that liquidity-wise any 2 of 3 combination is sufficient,
4354 // two cheaper paths will be taken.
4355 // These paths have equal available liquidity.
4357 // We need a combination of 3 paths:
4358 // From our node to node3 via {node0, node2}, {node7, node2, node4} and {node7, node2}.
4359 // Note that these paths overlap (channels 5, 12, 13).
4360 // Each path will have 100 sats capacity, those channels which
4361 // are used twice will have 200 sats capacity.
4363 // Disable other potential paths.
4364 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4365 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4366 short_channel_id: 2,
4369 cltv_expiry_delta: 0,
4370 htlc_minimum_msat: 0,
4371 htlc_maximum_msat: OptionalField::Present(100_000),
4373 fee_proportional_millionths: 0,
4374 excess_data: Vec::new()
4376 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4377 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4378 short_channel_id: 7,
4381 cltv_expiry_delta: 0,
4382 htlc_minimum_msat: 0,
4383 htlc_maximum_msat: OptionalField::Present(100_000),
4385 fee_proportional_millionths: 0,
4386 excess_data: Vec::new()
4389 // Path via {node0, node2} is channels {1, 3, 5}.
4390 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4391 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4392 short_channel_id: 1,
4395 cltv_expiry_delta: 0,
4396 htlc_minimum_msat: 0,
4397 htlc_maximum_msat: OptionalField::Present(100_000),
4399 fee_proportional_millionths: 0,
4400 excess_data: Vec::new()
4402 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4403 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4404 short_channel_id: 3,
4407 cltv_expiry_delta: 0,
4408 htlc_minimum_msat: 0,
4409 htlc_maximum_msat: OptionalField::Present(100_000),
4411 fee_proportional_millionths: 0,
4412 excess_data: Vec::new()
4415 // Capacity of 200 sats because this channel will be used by 3rd path as well.
4416 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4417 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4418 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4419 short_channel_id: 5,
4422 cltv_expiry_delta: 0,
4423 htlc_minimum_msat: 0,
4424 htlc_maximum_msat: OptionalField::Present(200_000),
4426 fee_proportional_millionths: 0,
4427 excess_data: Vec::new()
4430 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4431 // Add 100 sats to the capacities of {12, 13}, because these channels
4432 // are also used for 3rd path. 100 sats for the rest. Total capacity: 100 sats.
4433 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4434 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4435 short_channel_id: 12,
4438 cltv_expiry_delta: 0,
4439 htlc_minimum_msat: 0,
4440 htlc_maximum_msat: OptionalField::Present(200_000),
4442 fee_proportional_millionths: 0,
4443 excess_data: Vec::new()
4445 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4446 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4447 short_channel_id: 13,
4450 cltv_expiry_delta: 0,
4451 htlc_minimum_msat: 0,
4452 htlc_maximum_msat: OptionalField::Present(200_000),
4454 fee_proportional_millionths: 0,
4455 excess_data: Vec::new()
4458 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4459 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4460 short_channel_id: 6,
4463 cltv_expiry_delta: 0,
4464 htlc_minimum_msat: 0,
4465 htlc_maximum_msat: OptionalField::Present(100_000),
4466 fee_base_msat: 1_000,
4467 fee_proportional_millionths: 0,
4468 excess_data: Vec::new()
4470 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4471 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4472 short_channel_id: 11,
4475 cltv_expiry_delta: 0,
4476 htlc_minimum_msat: 0,
4477 htlc_maximum_msat: OptionalField::Present(100_000),
4479 fee_proportional_millionths: 0,
4480 excess_data: Vec::new()
4483 // Path via {node7, node2} is channels {12, 13, 5}.
4484 // We already limited them to 200 sats (they are used twice for 100 sats).
4485 // Nothing to do here.
4488 // Now, attempt to route 180 sats.
4489 // Our algorithm should provide us with these 2 paths.
4490 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 180_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4491 assert_eq!(route.paths.len(), 2);
4493 let mut total_value_transferred_msat = 0;
4494 let mut total_paid_msat = 0;
4495 for path in &route.paths {
4496 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4497 total_value_transferred_msat += path.last().unwrap().fee_msat;
4499 total_paid_msat += hop.fee_msat;
4502 // If we paid fee, this would be higher.
4503 assert_eq!(total_value_transferred_msat, 180_000);
4504 let total_fees_paid = total_paid_msat - total_value_transferred_msat;
4505 assert_eq!(total_fees_paid, 0);
4510 fn fees_on_mpp_route_test() {
4511 // This test makes sure that MPP algorithm properly takes into account
4512 // fees charged on the channels, by making the fees impactful:
4513 // if the fee is not properly accounted for, the behavior is different.
4514 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4515 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4516 let scorer = test_utils::TestScorer::with_penalty(0);
4517 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4518 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4519 let payment_params = PaymentParameters::from_node_id(nodes[3]).with_features(InvoiceFeatures::known());
4521 // We need a route consisting of 2 paths:
4522 // From our node to node3 via {node0, node2} and {node7, node2, node4}.
4523 // We will route 200 sats, Each path will have 100 sats capacity.
4525 // This test is not particularly stable: e.g.,
4526 // there's a way to route via {node0, node2, node4}.
4527 // It works while pathfinding is deterministic, but can be broken otherwise.
4528 // It's fine to ignore this concern for now.
4530 // Disable other potential paths.
4531 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4532 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4533 short_channel_id: 2,
4536 cltv_expiry_delta: 0,
4537 htlc_minimum_msat: 0,
4538 htlc_maximum_msat: OptionalField::Present(100_000),
4540 fee_proportional_millionths: 0,
4541 excess_data: Vec::new()
4544 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4545 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4546 short_channel_id: 7,
4549 cltv_expiry_delta: 0,
4550 htlc_minimum_msat: 0,
4551 htlc_maximum_msat: OptionalField::Present(100_000),
4553 fee_proportional_millionths: 0,
4554 excess_data: Vec::new()
4557 // Path via {node0, node2} is channels {1, 3, 5}.
4558 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4559 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4560 short_channel_id: 1,
4563 cltv_expiry_delta: 0,
4564 htlc_minimum_msat: 0,
4565 htlc_maximum_msat: OptionalField::Present(100_000),
4567 fee_proportional_millionths: 0,
4568 excess_data: Vec::new()
4570 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4571 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4572 short_channel_id: 3,
4575 cltv_expiry_delta: 0,
4576 htlc_minimum_msat: 0,
4577 htlc_maximum_msat: OptionalField::Present(100_000),
4579 fee_proportional_millionths: 0,
4580 excess_data: Vec::new()
4583 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4584 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4585 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4586 short_channel_id: 5,
4589 cltv_expiry_delta: 0,
4590 htlc_minimum_msat: 0,
4591 htlc_maximum_msat: OptionalField::Present(100_000),
4593 fee_proportional_millionths: 0,
4594 excess_data: Vec::new()
4597 // Path via {node7, node2, node4} is channels {12, 13, 6, 11}.
4598 // All channels should be 100 sats capacity. But for the fee experiment,
4599 // we'll add absolute fee of 150 sats paid for the use channel 6 (paid to node2 on channel 13).
4600 // Since channel 12 allows to deliver only 250 sats to channel 13, channel 13 can transfer only
4601 // 100 sats (and pay 150 sats in fees for the use of channel 6),
4602 // so no matter how large are other channels,
4603 // the whole path will be limited by 100 sats with just these 2 conditions:
4604 // - channel 12 capacity is 250 sats
4605 // - fee for channel 6 is 150 sats
4606 // Let's test this by enforcing these 2 conditions and removing other limits.
4607 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4608 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4609 short_channel_id: 12,
4612 cltv_expiry_delta: 0,
4613 htlc_minimum_msat: 0,
4614 htlc_maximum_msat: OptionalField::Present(250_000),
4616 fee_proportional_millionths: 0,
4617 excess_data: Vec::new()
4619 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4620 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4621 short_channel_id: 13,
4624 cltv_expiry_delta: 0,
4625 htlc_minimum_msat: 0,
4626 htlc_maximum_msat: OptionalField::Absent,
4628 fee_proportional_millionths: 0,
4629 excess_data: Vec::new()
4632 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
4633 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4634 short_channel_id: 6,
4637 cltv_expiry_delta: 0,
4638 htlc_minimum_msat: 0,
4639 htlc_maximum_msat: OptionalField::Absent,
4640 fee_base_msat: 150_000,
4641 fee_proportional_millionths: 0,
4642 excess_data: Vec::new()
4644 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4645 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4646 short_channel_id: 11,
4649 cltv_expiry_delta: 0,
4650 htlc_minimum_msat: 0,
4651 htlc_maximum_msat: OptionalField::Absent,
4653 fee_proportional_millionths: 0,
4654 excess_data: Vec::new()
4658 // Attempt to route more than available results in a failure.
4659 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4660 &our_id, &payment_params, &network_graph.read_only(), None, 210_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4661 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4662 } else { panic!(); }
4666 // Now, attempt to route 200 sats (exact amount we can route).
4667 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 200_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4668 assert_eq!(route.paths.len(), 2);
4670 let mut total_amount_paid_msat = 0;
4671 for path in &route.paths {
4672 assert_eq!(path.last().unwrap().pubkey, nodes[3]);
4673 total_amount_paid_msat += path.last().unwrap().fee_msat;
4675 assert_eq!(total_amount_paid_msat, 200_000);
4676 assert_eq!(route.get_total_fees(), 150_000);
4681 fn mpp_with_last_hops() {
4682 // Previously, if we tried to send an MPP payment to a destination which was only reachable
4683 // via a single last-hop route hint, we'd fail to route if we first collected routes
4684 // totaling close but not quite enough to fund the full payment.
4686 // This was because we considered last-hop hints to have exactly the sought payment amount
4687 // instead of the amount we were trying to collect, needlessly limiting our path searching
4688 // at the very first hop.
4690 // Specifically, this interacted with our "all paths must fund at least 5% of total target"
4691 // criterion to cause us to refuse all routes at the last hop hint which would be considered
4692 // to only have the remaining to-collect amount in available liquidity.
4694 // This bug appeared in production in some specific channel configurations.
4695 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4696 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4697 let scorer = test_utils::TestScorer::with_penalty(0);
4698 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4699 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4700 let payment_params = PaymentParameters::from_node_id(PublicKey::from_slice(&[02; 33]).unwrap()).with_features(InvoiceFeatures::known())
4701 .with_route_hints(vec![RouteHint(vec![RouteHintHop {
4702 src_node_id: nodes[2],
4703 short_channel_id: 42,
4704 fees: RoutingFees { base_msat: 0, proportional_millionths: 0 },
4705 cltv_expiry_delta: 42,
4706 htlc_minimum_msat: None,
4707 htlc_maximum_msat: None,
4710 // Keep only two paths from us to nodes[2], both with a 99sat HTLC maximum, with one with
4711 // no fee and one with a 1msat fee. Previously, trying to route 100 sats to nodes[2] here
4712 // would first use the no-fee route and then fail to find a path along the second route as
4713 // we think we can only send up to 1 additional sat over the last-hop but refuse to as its
4714 // under 5% of our payment amount.
4715 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4716 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4717 short_channel_id: 1,
4720 cltv_expiry_delta: (5 << 4) | 5,
4721 htlc_minimum_msat: 0,
4722 htlc_maximum_msat: OptionalField::Present(99_000),
4723 fee_base_msat: u32::max_value(),
4724 fee_proportional_millionths: u32::max_value(),
4725 excess_data: Vec::new()
4727 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4728 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4729 short_channel_id: 2,
4732 cltv_expiry_delta: (5 << 4) | 3,
4733 htlc_minimum_msat: 0,
4734 htlc_maximum_msat: OptionalField::Present(99_000),
4735 fee_base_msat: u32::max_value(),
4736 fee_proportional_millionths: u32::max_value(),
4737 excess_data: Vec::new()
4739 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4740 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4741 short_channel_id: 4,
4744 cltv_expiry_delta: (4 << 4) | 1,
4745 htlc_minimum_msat: 0,
4746 htlc_maximum_msat: OptionalField::Absent,
4748 fee_proportional_millionths: 0,
4749 excess_data: Vec::new()
4751 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4752 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4753 short_channel_id: 13,
4755 flags: 0|2, // Channel disabled
4756 cltv_expiry_delta: (13 << 4) | 1,
4757 htlc_minimum_msat: 0,
4758 htlc_maximum_msat: OptionalField::Absent,
4760 fee_proportional_millionths: 2000000,
4761 excess_data: Vec::new()
4764 // Get a route for 100 sats and check that we found the MPP route no problem and didn't
4766 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4767 assert_eq!(route.paths.len(), 2);
4768 // Paths are somewhat randomly ordered, but:
4769 // * the first is channel 2 (1 msat fee) -> channel 4 -> channel 42
4770 // * the second is channel 1 (0 fee, but 99 sat maximum) -> channel 3 -> channel 42
4771 assert_eq!(route.paths[0][0].short_channel_id, 2);
4772 assert_eq!(route.paths[0][0].fee_msat, 1);
4773 assert_eq!(route.paths[0][2].fee_msat, 1_000);
4774 assert_eq!(route.paths[1][0].short_channel_id, 1);
4775 assert_eq!(route.paths[1][0].fee_msat, 0);
4776 assert_eq!(route.paths[1][2].fee_msat, 99_000);
4777 assert_eq!(route.get_total_fees(), 1);
4778 assert_eq!(route.get_total_amount(), 100_000);
4782 fn drop_lowest_channel_mpp_route_test() {
4783 // This test checks that low-capacity channel is dropped when after
4784 // path finding we realize that we found more capacity than we need.
4785 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
4786 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4787 let scorer = test_utils::TestScorer::with_penalty(0);
4788 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4789 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4790 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
4792 // We need a route consisting of 3 paths:
4793 // From our node to node2 via node0, node7, node1 (three paths one hop each).
4795 // The first and the second paths should be sufficient, but the third should be
4796 // cheaper, so that we select it but drop later.
4798 // First, we set limits on these (previously unlimited) channels.
4799 // Their aggregate capacity will be 50 + 60 + 20 = 130 sats.
4801 // Path via node0 is channels {1, 3}. Limit them to 100 and 50 sats (total limit 50);
4802 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4803 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4804 short_channel_id: 1,
4807 cltv_expiry_delta: 0,
4808 htlc_minimum_msat: 0,
4809 htlc_maximum_msat: OptionalField::Present(100_000),
4811 fee_proportional_millionths: 0,
4812 excess_data: Vec::new()
4814 update_channel(&gossip_sync, &secp_ctx, &privkeys[0], UnsignedChannelUpdate {
4815 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4816 short_channel_id: 3,
4819 cltv_expiry_delta: 0,
4820 htlc_minimum_msat: 0,
4821 htlc_maximum_msat: OptionalField::Present(50_000),
4823 fee_proportional_millionths: 0,
4824 excess_data: Vec::new()
4827 // Path via node7 is channels {12, 13}. Limit them to 60 and 60 sats (total limit 60);
4828 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4829 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4830 short_channel_id: 12,
4833 cltv_expiry_delta: 0,
4834 htlc_minimum_msat: 0,
4835 htlc_maximum_msat: OptionalField::Present(60_000),
4837 fee_proportional_millionths: 0,
4838 excess_data: Vec::new()
4840 update_channel(&gossip_sync, &secp_ctx, &privkeys[7], UnsignedChannelUpdate {
4841 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4842 short_channel_id: 13,
4845 cltv_expiry_delta: 0,
4846 htlc_minimum_msat: 0,
4847 htlc_maximum_msat: OptionalField::Present(60_000),
4849 fee_proportional_millionths: 0,
4850 excess_data: Vec::new()
4853 // Path via node1 is channels {2, 4}. Limit them to 20 and 20 sats (total capacity 20 sats).
4854 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4855 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4856 short_channel_id: 2,
4859 cltv_expiry_delta: 0,
4860 htlc_minimum_msat: 0,
4861 htlc_maximum_msat: OptionalField::Present(20_000),
4863 fee_proportional_millionths: 0,
4864 excess_data: Vec::new()
4866 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4867 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4868 short_channel_id: 4,
4871 cltv_expiry_delta: 0,
4872 htlc_minimum_msat: 0,
4873 htlc_maximum_msat: OptionalField::Present(20_000),
4875 fee_proportional_millionths: 0,
4876 excess_data: Vec::new()
4880 // Attempt to route more than available results in a failure.
4881 if let Err(LightningError{err, action: ErrorAction::IgnoreError}) = get_route(
4882 &our_id, &payment_params, &network_graph.read_only(), None, 150_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes) {
4883 assert_eq!(err, "Failed to find a sufficient route to the given destination");
4884 } else { panic!(); }
4888 // Now, attempt to route 125 sats (just a bit below the capacity of 3 channels).
4889 // Our algorithm should provide us with these 3 paths.
4890 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 125_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4891 assert_eq!(route.paths.len(), 3);
4892 let mut total_amount_paid_msat = 0;
4893 for path in &route.paths {
4894 assert_eq!(path.len(), 2);
4895 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4896 total_amount_paid_msat += path.last().unwrap().fee_msat;
4898 assert_eq!(total_amount_paid_msat, 125_000);
4902 // Attempt to route without the last small cheap channel
4903 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
4904 assert_eq!(route.paths.len(), 2);
4905 let mut total_amount_paid_msat = 0;
4906 for path in &route.paths {
4907 assert_eq!(path.len(), 2);
4908 assert_eq!(path.last().unwrap().pubkey, nodes[2]);
4909 total_amount_paid_msat += path.last().unwrap().fee_msat;
4911 assert_eq!(total_amount_paid_msat, 90_000);
4916 fn min_criteria_consistency() {
4917 // Test that we don't use an inconsistent metric between updating and walking nodes during
4918 // our Dijkstra's pass. In the initial version of MPP, the "best source" for a given node
4919 // was updated with a different criterion from the heap sorting, resulting in loops in
4920 // calculated paths. We test for that specific case here.
4922 // We construct a network that looks like this:
4924 // node2 -1(3)2- node3
4928 // node1 -1(5)2- node4 -1(1)2- node6
4934 // We create a loop on the side of our real path - our destination is node 6, with a
4935 // previous hop of node 4. From 4, the cheapest previous path is channel 2 from node 2,
4936 // followed by node 3 over channel 3. Thereafter, the cheapest next-hop is back to node 4
4937 // (this time over channel 4). Channel 4 has 0 htlc_minimum_msat whereas channel 1 (the
4938 // other channel with a previous-hop of node 4) has a high (but irrelevant to the overall
4939 // payment) htlc_minimum_msat. In the original algorithm, this resulted in node4's
4940 // "previous hop" being set to node 3, creating a loop in the path.
4941 let secp_ctx = Secp256k1::new();
4942 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
4943 let logger = Arc::new(test_utils::TestLogger::new());
4944 let network = Arc::new(NetworkGraph::new(genesis_hash, Arc::clone(&logger)));
4945 let gossip_sync = P2PGossipSync::new(Arc::clone(&network), None, Arc::clone(&logger));
4946 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
4947 let scorer = test_utils::TestScorer::with_penalty(0);
4948 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
4949 let random_seed_bytes = keys_manager.get_secure_random_bytes();
4950 let payment_params = PaymentParameters::from_node_id(nodes[6]);
4952 add_channel(&gossip_sync, &secp_ctx, &our_privkey, &privkeys[1], ChannelFeatures::from_le_bytes(id_to_feature_flags(6)), 6);
4953 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
4954 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4955 short_channel_id: 6,
4958 cltv_expiry_delta: (6 << 4) | 0,
4959 htlc_minimum_msat: 0,
4960 htlc_maximum_msat: OptionalField::Absent,
4962 fee_proportional_millionths: 0,
4963 excess_data: Vec::new()
4965 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[1], NodeFeatures::from_le_bytes(id_to_feature_flags(1)), 0);
4967 add_channel(&gossip_sync, &secp_ctx, &privkeys[1], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(5)), 5);
4968 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
4969 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4970 short_channel_id: 5,
4973 cltv_expiry_delta: (5 << 4) | 0,
4974 htlc_minimum_msat: 0,
4975 htlc_maximum_msat: OptionalField::Absent,
4977 fee_proportional_millionths: 0,
4978 excess_data: Vec::new()
4980 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[4], NodeFeatures::from_le_bytes(id_to_feature_flags(4)), 0);
4982 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[3], ChannelFeatures::from_le_bytes(id_to_feature_flags(4)), 4);
4983 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
4984 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
4985 short_channel_id: 4,
4988 cltv_expiry_delta: (4 << 4) | 0,
4989 htlc_minimum_msat: 0,
4990 htlc_maximum_msat: OptionalField::Absent,
4992 fee_proportional_millionths: 0,
4993 excess_data: Vec::new()
4995 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[3], NodeFeatures::from_le_bytes(id_to_feature_flags(3)), 0);
4997 add_channel(&gossip_sync, &secp_ctx, &privkeys[3], &privkeys[2], ChannelFeatures::from_le_bytes(id_to_feature_flags(3)), 3);
4998 update_channel(&gossip_sync, &secp_ctx, &privkeys[3], UnsignedChannelUpdate {
4999 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5000 short_channel_id: 3,
5003 cltv_expiry_delta: (3 << 4) | 0,
5004 htlc_minimum_msat: 0,
5005 htlc_maximum_msat: OptionalField::Absent,
5007 fee_proportional_millionths: 0,
5008 excess_data: Vec::new()
5010 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[2], NodeFeatures::from_le_bytes(id_to_feature_flags(2)), 0);
5012 add_channel(&gossip_sync, &secp_ctx, &privkeys[2], &privkeys[4], ChannelFeatures::from_le_bytes(id_to_feature_flags(2)), 2);
5013 update_channel(&gossip_sync, &secp_ctx, &privkeys[2], UnsignedChannelUpdate {
5014 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5015 short_channel_id: 2,
5018 cltv_expiry_delta: (2 << 4) | 0,
5019 htlc_minimum_msat: 0,
5020 htlc_maximum_msat: OptionalField::Absent,
5022 fee_proportional_millionths: 0,
5023 excess_data: Vec::new()
5026 add_channel(&gossip_sync, &secp_ctx, &privkeys[4], &privkeys[6], ChannelFeatures::from_le_bytes(id_to_feature_flags(1)), 1);
5027 update_channel(&gossip_sync, &secp_ctx, &privkeys[4], UnsignedChannelUpdate {
5028 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5029 short_channel_id: 1,
5032 cltv_expiry_delta: (1 << 4) | 0,
5033 htlc_minimum_msat: 100,
5034 htlc_maximum_msat: OptionalField::Absent,
5036 fee_proportional_millionths: 0,
5037 excess_data: Vec::new()
5039 add_or_update_node(&gossip_sync, &secp_ctx, &privkeys[6], NodeFeatures::from_le_bytes(id_to_feature_flags(6)), 0);
5042 // Now ensure the route flows simply over nodes 1 and 4 to 6.
5043 let route = get_route(&our_id, &payment_params, &network.read_only(), None, 10_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5044 assert_eq!(route.paths.len(), 1);
5045 assert_eq!(route.paths[0].len(), 3);
5047 assert_eq!(route.paths[0][0].pubkey, nodes[1]);
5048 assert_eq!(route.paths[0][0].short_channel_id, 6);
5049 assert_eq!(route.paths[0][0].fee_msat, 100);
5050 assert_eq!(route.paths[0][0].cltv_expiry_delta, (5 << 4) | 0);
5051 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(1));
5052 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(6));
5054 assert_eq!(route.paths[0][1].pubkey, nodes[4]);
5055 assert_eq!(route.paths[0][1].short_channel_id, 5);
5056 assert_eq!(route.paths[0][1].fee_msat, 0);
5057 assert_eq!(route.paths[0][1].cltv_expiry_delta, (1 << 4) | 0);
5058 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(4));
5059 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(5));
5061 assert_eq!(route.paths[0][2].pubkey, nodes[6]);
5062 assert_eq!(route.paths[0][2].short_channel_id, 1);
5063 assert_eq!(route.paths[0][2].fee_msat, 10_000);
5064 assert_eq!(route.paths[0][2].cltv_expiry_delta, 42);
5065 assert_eq!(route.paths[0][2].node_features.le_flags(), &id_to_feature_flags(6));
5066 assert_eq!(route.paths[0][2].channel_features.le_flags(), &id_to_feature_flags(1));
5072 fn exact_fee_liquidity_limit() {
5073 // Test that if, while walking the graph, we find a hop that has exactly enough liquidity
5074 // for us, including later hop fees, we take it. In the first version of our MPP algorithm
5075 // we calculated fees on a higher value, resulting in us ignoring such paths.
5076 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5077 let (our_privkey, our_id, _, nodes) = get_nodes(&secp_ctx);
5078 let scorer = test_utils::TestScorer::with_penalty(0);
5079 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5080 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5081 let payment_params = PaymentParameters::from_node_id(nodes[2]);
5083 // We modify the graph to set the htlc_maximum of channel 2 to below the value we wish to
5085 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5086 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5087 short_channel_id: 2,
5090 cltv_expiry_delta: 0,
5091 htlc_minimum_msat: 0,
5092 htlc_maximum_msat: OptionalField::Present(85_000),
5094 fee_proportional_millionths: 0,
5095 excess_data: Vec::new()
5098 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5099 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5100 short_channel_id: 12,
5103 cltv_expiry_delta: (4 << 4) | 1,
5104 htlc_minimum_msat: 0,
5105 htlc_maximum_msat: OptionalField::Present(270_000),
5107 fee_proportional_millionths: 1000000,
5108 excess_data: Vec::new()
5112 // Now, attempt to route 90 sats, which is exactly 90 sats at the last hop, plus the
5113 // 200% fee charged channel 13 in the 1-to-2 direction.
5114 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5115 assert_eq!(route.paths.len(), 1);
5116 assert_eq!(route.paths[0].len(), 2);
5118 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5119 assert_eq!(route.paths[0][0].short_channel_id, 12);
5120 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5121 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5122 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5123 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5125 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5126 assert_eq!(route.paths[0][1].short_channel_id, 13);
5127 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5128 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5129 assert_eq!(route.paths[0][1].node_features.le_flags(), &id_to_feature_flags(3));
5130 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5135 fn htlc_max_reduction_below_min() {
5136 // Test that if, while walking the graph, we reduce the value being sent to meet an
5137 // htlc_maximum_msat, we don't end up undershooting a later htlc_minimum_msat. In the
5138 // initial version of MPP we'd accept such routes but reject them while recalculating fees,
5139 // resulting in us thinking there is no possible path, even if other paths exist.
5140 let (secp_ctx, network_graph, gossip_sync, _, logger) = build_graph();
5141 let (our_privkey, our_id, privkeys, nodes) = get_nodes(&secp_ctx);
5142 let scorer = test_utils::TestScorer::with_penalty(0);
5143 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5144 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5145 let payment_params = PaymentParameters::from_node_id(nodes[2]).with_features(InvoiceFeatures::known());
5147 // We modify the graph to set the htlc_minimum of channel 2 and 4 as needed - channel 2
5148 // gets an htlc_maximum_msat of 80_000 and channel 4 an htlc_minimum_msat of 90_000. We
5149 // then try to send 90_000.
5150 update_channel(&gossip_sync, &secp_ctx, &our_privkey, UnsignedChannelUpdate {
5151 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5152 short_channel_id: 2,
5155 cltv_expiry_delta: 0,
5156 htlc_minimum_msat: 0,
5157 htlc_maximum_msat: OptionalField::Present(80_000),
5159 fee_proportional_millionths: 0,
5160 excess_data: Vec::new()
5162 update_channel(&gossip_sync, &secp_ctx, &privkeys[1], UnsignedChannelUpdate {
5163 chain_hash: genesis_block(Network::Testnet).header.block_hash(),
5164 short_channel_id: 4,
5167 cltv_expiry_delta: (4 << 4) | 1,
5168 htlc_minimum_msat: 90_000,
5169 htlc_maximum_msat: OptionalField::Absent,
5171 fee_proportional_millionths: 0,
5172 excess_data: Vec::new()
5176 // Now, attempt to route 90 sats, hitting the htlc_minimum on channel 4, but
5177 // overshooting the htlc_maximum on channel 2. Thus, we should pick the (absurdly
5178 // expensive) channels 12-13 path.
5179 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 90_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5180 assert_eq!(route.paths.len(), 1);
5181 assert_eq!(route.paths[0].len(), 2);
5183 assert_eq!(route.paths[0][0].pubkey, nodes[7]);
5184 assert_eq!(route.paths[0][0].short_channel_id, 12);
5185 assert_eq!(route.paths[0][0].fee_msat, 90_000*2);
5186 assert_eq!(route.paths[0][0].cltv_expiry_delta, (13 << 4) | 1);
5187 assert_eq!(route.paths[0][0].node_features.le_flags(), &id_to_feature_flags(8));
5188 assert_eq!(route.paths[0][0].channel_features.le_flags(), &id_to_feature_flags(12));
5190 assert_eq!(route.paths[0][1].pubkey, nodes[2]);
5191 assert_eq!(route.paths[0][1].short_channel_id, 13);
5192 assert_eq!(route.paths[0][1].fee_msat, 90_000);
5193 assert_eq!(route.paths[0][1].cltv_expiry_delta, 42);
5194 assert_eq!(route.paths[0][1].node_features.le_flags(), InvoiceFeatures::known().le_flags());
5195 assert_eq!(route.paths[0][1].channel_features.le_flags(), &id_to_feature_flags(13));
5200 fn multiple_direct_first_hops() {
5201 // Previously we'd only ever considered one first hop path per counterparty.
5202 // However, as we don't restrict users to one channel per peer, we really need to support
5203 // looking at all first hop paths.
5204 // Here we test that we do not ignore all-but-the-last first hop paths per counterparty (as
5205 // we used to do by overwriting the `first_hop_targets` hashmap entry) and that we can MPP
5206 // route over multiple channels with the same first hop.
5207 let secp_ctx = Secp256k1::new();
5208 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5209 let genesis_hash = genesis_block(Network::Testnet).header.block_hash();
5210 let logger = Arc::new(test_utils::TestLogger::new());
5211 let network_graph = NetworkGraph::new(genesis_hash, Arc::clone(&logger));
5212 let scorer = test_utils::TestScorer::with_penalty(0);
5213 let payment_params = PaymentParameters::from_node_id(nodes[0]).with_features(InvoiceFeatures::known());
5214 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5215 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5218 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5219 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 200_000),
5220 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 10_000),
5221 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5222 assert_eq!(route.paths.len(), 1);
5223 assert_eq!(route.paths[0].len(), 1);
5225 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5226 assert_eq!(route.paths[0][0].short_channel_id, 3);
5227 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5230 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5231 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5232 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5233 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5234 assert_eq!(route.paths.len(), 2);
5235 assert_eq!(route.paths[0].len(), 1);
5236 assert_eq!(route.paths[1].len(), 1);
5238 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5239 assert_eq!(route.paths[0][0].short_channel_id, 3);
5240 assert_eq!(route.paths[0][0].fee_msat, 50_000);
5242 assert_eq!(route.paths[1][0].pubkey, nodes[0]);
5243 assert_eq!(route.paths[1][0].short_channel_id, 2);
5244 assert_eq!(route.paths[1][0].fee_msat, 50_000);
5248 // If we have a bunch of outbound channels to the same node, where most are not
5249 // sufficient to pay the full payment, but one is, we should default to just using the
5250 // one single channel that has sufficient balance, avoiding MPP.
5252 // If we have several options above the 3xpayment value threshold, we should pick the
5253 // smallest of them, avoiding further fragmenting our available outbound balance to
5255 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), Some(&[
5256 &get_channel_details(Some(2), nodes[0], InitFeatures::known(), 50_000),
5257 &get_channel_details(Some(3), nodes[0], InitFeatures::known(), 50_000),
5258 &get_channel_details(Some(5), nodes[0], InitFeatures::known(), 50_000),
5259 &get_channel_details(Some(6), nodes[0], InitFeatures::known(), 300_000),
5260 &get_channel_details(Some(7), nodes[0], InitFeatures::known(), 50_000),
5261 &get_channel_details(Some(8), nodes[0], InitFeatures::known(), 50_000),
5262 &get_channel_details(Some(9), nodes[0], InitFeatures::known(), 50_000),
5263 &get_channel_details(Some(4), nodes[0], InitFeatures::known(), 1_000_000),
5264 ]), 100_000, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5265 assert_eq!(route.paths.len(), 1);
5266 assert_eq!(route.paths[0].len(), 1);
5268 assert_eq!(route.paths[0][0].pubkey, nodes[0]);
5269 assert_eq!(route.paths[0][0].short_channel_id, 6);
5270 assert_eq!(route.paths[0][0].fee_msat, 100_000);
5275 fn prefers_shorter_route_with_higher_fees() {
5276 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5277 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5278 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5280 // Without penalizing each hop 100 msats, a longer path with lower fees is chosen.
5281 let scorer = test_utils::TestScorer::with_penalty(0);
5282 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5283 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5284 let route = get_route(
5285 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5286 Arc::clone(&logger), &scorer, &random_seed_bytes
5288 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5290 assert_eq!(route.get_total_fees(), 100);
5291 assert_eq!(route.get_total_amount(), 100);
5292 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5294 // Applying a 100 msat penalty to each hop results in taking channels 7 and 10 to nodes[6]
5295 // from nodes[2] rather than channel 6, 11, and 8, even though the longer path is cheaper.
5296 let scorer = test_utils::TestScorer::with_penalty(100);
5297 let route = get_route(
5298 &our_id, &payment_params, &network_graph.read_only(), None, 100, 42,
5299 Arc::clone(&logger), &scorer, &random_seed_bytes
5301 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5303 assert_eq!(route.get_total_fees(), 300);
5304 assert_eq!(route.get_total_amount(), 100);
5305 assert_eq!(path, vec![2, 4, 7, 10]);
5308 struct BadChannelScorer {
5309 short_channel_id: u64,
5313 impl Writeable for BadChannelScorer {
5314 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5316 impl Score for BadChannelScorer {
5317 fn channel_penalty_msat(&self, short_channel_id: u64, _: &NodeId, _: &NodeId, _: ChannelUsage) -> u64 {
5318 if short_channel_id == self.short_channel_id { u64::max_value() } else { 0 }
5321 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5322 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5323 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5324 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
5327 struct BadNodeScorer {
5332 impl Writeable for BadNodeScorer {
5333 fn write<W: Writer>(&self, _w: &mut W) -> Result<(), ::io::Error> { unimplemented!() }
5336 impl Score for BadNodeScorer {
5337 fn channel_penalty_msat(&self, _: u64, _: &NodeId, target: &NodeId, _: ChannelUsage) -> u64 {
5338 if *target == self.node_id { u64::max_value() } else { 0 }
5341 fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5342 fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
5343 fn probe_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
5344 fn probe_successful(&mut self, _path: &[&RouteHop]) {}
5348 fn avoids_routing_through_bad_channels_and_nodes() {
5349 let (secp_ctx, network, _, _, logger) = build_graph();
5350 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5351 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5352 let network_graph = network.read_only();
5354 // A path to nodes[6] exists when no penalties are applied to any channel.
5355 let scorer = test_utils::TestScorer::with_penalty(0);
5356 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5357 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5358 let route = get_route(
5359 &our_id, &payment_params, &network_graph, None, 100, 42,
5360 Arc::clone(&logger), &scorer, &random_seed_bytes
5362 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5364 assert_eq!(route.get_total_fees(), 100);
5365 assert_eq!(route.get_total_amount(), 100);
5366 assert_eq!(path, vec![2, 4, 6, 11, 8]);
5368 // A different path to nodes[6] exists if channel 6 cannot be routed over.
5369 let scorer = BadChannelScorer { short_channel_id: 6 };
5370 let route = get_route(
5371 &our_id, &payment_params, &network_graph, None, 100, 42,
5372 Arc::clone(&logger), &scorer, &random_seed_bytes
5374 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5376 assert_eq!(route.get_total_fees(), 300);
5377 assert_eq!(route.get_total_amount(), 100);
5378 assert_eq!(path, vec![2, 4, 7, 10]);
5380 // A path to nodes[6] does not exist if nodes[2] cannot be routed through.
5381 let scorer = BadNodeScorer { node_id: NodeId::from_pubkey(&nodes[2]) };
5383 &our_id, &payment_params, &network_graph, None, 100, 42,
5384 Arc::clone(&logger), &scorer, &random_seed_bytes
5386 Err(LightningError { err, .. } ) => {
5387 assert_eq!(err, "Failed to find a path to the given destination");
5389 Ok(_) => panic!("Expected error"),
5394 fn total_fees_single_path() {
5398 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5399 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5400 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5403 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5404 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5405 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5408 pubkey: PublicKey::from_slice(&hex::decode("027f31ebc5462c1fdce1b737ecff52d37d75dea43ce11c74d25aa297165faa2007").unwrap()[..]).unwrap(),
5409 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5410 short_channel_id: 0, fee_msat: 225, cltv_expiry_delta: 0
5413 payment_params: None,
5416 assert_eq!(route.get_total_fees(), 250);
5417 assert_eq!(route.get_total_amount(), 225);
5421 fn total_fees_multi_path() {
5425 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5426 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5427 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5430 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5431 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5432 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5436 pubkey: PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap(),
5437 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5438 short_channel_id: 0, fee_msat: 100, cltv_expiry_delta: 0
5441 pubkey: PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap(),
5442 channel_features: ChannelFeatures::empty(), node_features: NodeFeatures::empty(),
5443 short_channel_id: 0, fee_msat: 150, cltv_expiry_delta: 0
5446 payment_params: None,
5449 assert_eq!(route.get_total_fees(), 200);
5450 assert_eq!(route.get_total_amount(), 300);
5454 fn total_empty_route_no_panic() {
5455 // In an earlier version of `Route::get_total_fees` and `Route::get_total_amount`, they
5456 // would both panic if the route was completely empty. We test to ensure they return 0
5457 // here, even though its somewhat nonsensical as a route.
5458 let route = Route { paths: Vec::new(), payment_params: None };
5460 assert_eq!(route.get_total_fees(), 0);
5461 assert_eq!(route.get_total_amount(), 0);
5465 fn limits_total_cltv_delta() {
5466 let (secp_ctx, network, _, _, logger) = build_graph();
5467 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5468 let network_graph = network.read_only();
5470 let scorer = test_utils::TestScorer::with_penalty(0);
5472 // Make sure that generally there is at least one route available
5473 let feasible_max_total_cltv_delta = 1008;
5474 let feasible_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5475 .with_max_total_cltv_expiry_delta(feasible_max_total_cltv_delta);
5476 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5477 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5478 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5479 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5480 assert_ne!(path.len(), 0);
5482 // But not if we exclude all paths on the basis of their accumulated CLTV delta
5483 let fail_max_total_cltv_delta = 23;
5484 let fail_payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes))
5485 .with_max_total_cltv_expiry_delta(fail_max_total_cltv_delta);
5486 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0, Arc::clone(&logger), &scorer, &random_seed_bytes)
5488 Err(LightningError { err, .. } ) => {
5489 assert_eq!(err, "Failed to find a path to the given destination");
5491 Ok(_) => panic!("Expected error"),
5496 fn limits_path_length() {
5497 let (secp_ctx, network, _, _, logger) = build_line_graph();
5498 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5499 let network_graph = network.read_only();
5501 let scorer = test_utils::TestScorer::with_penalty(0);
5502 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5503 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5505 // First check we can actually create a long route on this graph.
5506 let feasible_payment_params = PaymentParameters::from_node_id(nodes[18]);
5507 let route = get_route(&our_id, &feasible_payment_params, &network_graph, None, 100, 0,
5508 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5509 let path = route.paths[0].iter().map(|hop| hop.short_channel_id).collect::<Vec<_>>();
5510 assert!(path.len() == MAX_PATH_LENGTH_ESTIMATE.into());
5512 // But we can't create a path surpassing the MAX_PATH_LENGTH_ESTIMATE limit.
5513 let fail_payment_params = PaymentParameters::from_node_id(nodes[19]);
5514 match get_route(&our_id, &fail_payment_params, &network_graph, None, 100, 0,
5515 Arc::clone(&logger), &scorer, &random_seed_bytes)
5517 Err(LightningError { err, .. } ) => {
5518 assert_eq!(err, "Failed to find a path to the given destination");
5520 Ok(_) => panic!("Expected error"),
5525 fn adds_and_limits_cltv_offset() {
5526 let (secp_ctx, network_graph, _, _, logger) = build_graph();
5527 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5529 let scorer = test_utils::TestScorer::with_penalty(0);
5531 let payment_params = PaymentParameters::from_node_id(nodes[6]).with_route_hints(last_hops(&nodes));
5532 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5533 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5534 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5535 assert_eq!(route.paths.len(), 1);
5537 let cltv_expiry_deltas_before = route.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5539 // Check whether the offset added to the last hop by default is in [1 .. DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA]
5540 let mut route_default = route.clone();
5541 add_random_cltv_offset(&mut route_default, &payment_params, &network_graph.read_only(), &random_seed_bytes);
5542 let cltv_expiry_deltas_default = route_default.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5543 assert_eq!(cltv_expiry_deltas_before.split_last().unwrap().1, cltv_expiry_deltas_default.split_last().unwrap().1);
5544 assert!(cltv_expiry_deltas_default.last() > cltv_expiry_deltas_before.last());
5545 assert!(cltv_expiry_deltas_default.last().unwrap() <= &DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA);
5547 // Check that no offset is added when we restrict the max_total_cltv_expiry_delta
5548 let mut route_limited = route.clone();
5549 let limited_max_total_cltv_expiry_delta = cltv_expiry_deltas_before.iter().sum();
5550 let limited_payment_params = payment_params.with_max_total_cltv_expiry_delta(limited_max_total_cltv_expiry_delta);
5551 add_random_cltv_offset(&mut route_limited, &limited_payment_params, &network_graph.read_only(), &random_seed_bytes);
5552 let cltv_expiry_deltas_limited = route_limited.paths[0].iter().map(|h| h.cltv_expiry_delta).collect::<Vec<u32>>();
5553 assert_eq!(cltv_expiry_deltas_before, cltv_expiry_deltas_limited);
5557 fn adds_plausible_cltv_offset() {
5558 let (secp_ctx, network, _, _, logger) = build_graph();
5559 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5560 let network_graph = network.read_only();
5561 let network_nodes = network_graph.nodes();
5562 let network_channels = network_graph.channels();
5563 let scorer = test_utils::TestScorer::with_penalty(0);
5564 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5565 let keys_manager = test_utils::TestKeysInterface::new(&[4u8; 32], Network::Testnet);
5566 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5568 let mut route = get_route(&our_id, &payment_params, &network_graph, None, 100, 0,
5569 Arc::clone(&logger), &scorer, &random_seed_bytes).unwrap();
5570 add_random_cltv_offset(&mut route, &payment_params, &network_graph, &random_seed_bytes);
5572 let mut path_plausibility = vec![];
5574 for p in route.paths {
5575 // 1. Select random observation point
5576 let mut prng = ChaCha20::new(&random_seed_bytes, &[0u8; 12]);
5577 let mut random_bytes = [0u8; ::core::mem::size_of::<usize>()];
5579 prng.process_in_place(&mut random_bytes);
5580 let random_path_index = usize::from_be_bytes(random_bytes).wrapping_rem(p.len());
5581 let observation_point = NodeId::from_pubkey(&p.get(random_path_index).unwrap().pubkey);
5583 // 2. Calculate what CLTV expiry delta we would observe there
5584 let observed_cltv_expiry_delta: u32 = p[random_path_index..].iter().map(|h| h.cltv_expiry_delta).sum();
5586 // 3. Starting from the observation point, find candidate paths
5587 let mut candidates: VecDeque<(NodeId, Vec<u32>)> = VecDeque::new();
5588 candidates.push_back((observation_point, vec![]));
5590 let mut found_plausible_candidate = false;
5592 'candidate_loop: while let Some((cur_node_id, cur_path_cltv_deltas)) = candidates.pop_front() {
5593 if let Some(remaining) = observed_cltv_expiry_delta.checked_sub(cur_path_cltv_deltas.iter().sum::<u32>()) {
5594 if remaining == 0 || remaining.wrapping_rem(40) == 0 || remaining.wrapping_rem(144) == 0 {
5595 found_plausible_candidate = true;
5596 break 'candidate_loop;
5600 if let Some(cur_node) = network_nodes.get(&cur_node_id) {
5601 for channel_id in &cur_node.channels {
5602 if let Some(channel_info) = network_channels.get(&channel_id) {
5603 if let Some((dir_info, next_id)) = channel_info.as_directed_from(&cur_node_id) {
5604 if let Some(channel_update_info) = dir_info.direction() {
5605 let next_cltv_expiry_delta = channel_update_info.cltv_expiry_delta as u32;
5606 if cur_path_cltv_deltas.iter().sum::<u32>()
5607 .saturating_add(next_cltv_expiry_delta) <= observed_cltv_expiry_delta {
5608 let mut new_path_cltv_deltas = cur_path_cltv_deltas.clone();
5609 new_path_cltv_deltas.push(next_cltv_expiry_delta);
5610 candidates.push_back((*next_id, new_path_cltv_deltas));
5619 path_plausibility.push(found_plausible_candidate);
5621 assert!(path_plausibility.iter().all(|x| *x));
5625 fn builds_correct_path_from_hops() {
5626 let (secp_ctx, network, _, _, logger) = build_graph();
5627 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5628 let network_graph = network.read_only();
5630 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5631 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5633 let payment_params = PaymentParameters::from_node_id(nodes[3]);
5634 let hops = [nodes[1], nodes[2], nodes[4], nodes[3]];
5635 let route = build_route_from_hops_internal(&our_id, &hops, &payment_params,
5636 &network_graph, 100, 0, Arc::clone(&logger), &random_seed_bytes).unwrap();
5637 let route_hop_pubkeys = route.paths[0].iter().map(|hop| hop.pubkey).collect::<Vec<_>>();
5638 assert_eq!(hops.len(), route.paths[0].len());
5639 for (idx, hop_pubkey) in hops.iter().enumerate() {
5640 assert!(*hop_pubkey == route_hop_pubkeys[idx]);
5644 #[cfg(not(feature = "no-std"))]
5645 pub(super) fn random_init_seed() -> u64 {
5646 // Because the default HashMap in std pulls OS randomness, we can use it as a (bad) RNG.
5647 use core::hash::{BuildHasher, Hasher};
5648 let seed = std::collections::hash_map::RandomState::new().build_hasher().finish();
5649 println!("Using seed of {}", seed);
5652 #[cfg(not(feature = "no-std"))]
5653 use util::ser::ReadableArgs;
5656 #[cfg(not(feature = "no-std"))]
5657 fn generate_routes() {
5658 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5660 let mut d = match super::test_utils::get_route_file() {
5667 let logger = test_utils::TestLogger::new();
5668 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5669 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5670 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5672 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5673 let mut seed = random_init_seed() as usize;
5674 let nodes = graph.read_only().nodes().clone();
5675 'load_endpoints: for _ in 0..10 {
5677 seed = seed.overflowing_mul(0xdeadbeef).0;
5678 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5679 seed = seed.overflowing_mul(0xdeadbeef).0;
5680 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5681 let payment_params = PaymentParameters::from_node_id(dst);
5682 let amt = seed as u64 % 200_000_000;
5683 let params = ProbabilisticScoringParameters::default();
5684 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5685 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5686 continue 'load_endpoints;
5693 #[cfg(not(feature = "no-std"))]
5694 fn generate_routes_mpp() {
5695 use routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
5697 let mut d = match super::test_utils::get_route_file() {
5704 let logger = test_utils::TestLogger::new();
5705 let graph = NetworkGraph::read(&mut d, &logger).unwrap();
5706 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5707 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5709 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5710 let mut seed = random_init_seed() as usize;
5711 let nodes = graph.read_only().nodes().clone();
5712 'load_endpoints: for _ in 0..10 {
5714 seed = seed.overflowing_mul(0xdeadbeef).0;
5715 let src = &PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5716 seed = seed.overflowing_mul(0xdeadbeef).0;
5717 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5718 let payment_params = PaymentParameters::from_node_id(dst).with_features(InvoiceFeatures::known());
5719 let amt = seed as u64 % 200_000_000;
5720 let params = ProbabilisticScoringParameters::default();
5721 let scorer = ProbabilisticScorer::new(params, &graph, &logger);
5722 if get_route(src, &payment_params, &graph.read_only(), None, amt, 42, &logger, &scorer, &random_seed_bytes).is_ok() {
5723 continue 'load_endpoints;
5730 fn honors_manual_penalties() {
5731 let (secp_ctx, network_graph, _, _, logger) = build_line_graph();
5732 let (_, our_id, _, nodes) = get_nodes(&secp_ctx);
5734 let keys_manager = test_utils::TestKeysInterface::new(&[0u8; 32], Network::Testnet);
5735 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5737 let scorer_params = ProbabilisticScoringParameters::default();
5738 let mut scorer = ProbabilisticScorer::new(scorer_params, Arc::clone(&network_graph), Arc::clone(&logger));
5740 // First check set manual penalties are returned by the scorer.
5741 let usage = ChannelUsage {
5743 inflight_htlc_msat: 0,
5744 effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000, htlc_maximum_msat: Some(1_000) },
5746 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[3]), 123);
5747 scorer.set_manual_penalty(&NodeId::from_pubkey(&nodes[4]), 456);
5748 assert_eq!(scorer.channel_penalty_msat(42, &NodeId::from_pubkey(&nodes[3]), &NodeId::from_pubkey(&nodes[4]), usage), 456);
5750 // Then check we can get a normal route
5751 let payment_params = PaymentParameters::from_node_id(nodes[10]);
5752 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5753 assert!(route.is_ok());
5755 // Then check that we can't get a route if we ban an intermediate node.
5756 scorer.add_banned(&NodeId::from_pubkey(&nodes[3]));
5757 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5758 assert!(route.is_err());
5760 // Finally make sure we can route again, when we remove the ban.
5761 scorer.remove_banned(&NodeId::from_pubkey(&nodes[3]));
5762 let route = get_route(&our_id, &payment_params, &network_graph.read_only(), None, 100, 42, Arc::clone(&logger), &scorer, &random_seed_bytes);
5763 assert!(route.is_ok());
5767 #[cfg(all(test, not(feature = "no-std")))]
5768 pub(crate) mod test_utils {
5770 /// Tries to open a network graph file, or panics with a URL to fetch it.
5771 pub(crate) fn get_route_file() -> Result<std::fs::File, &'static str> {
5772 let res = File::open("net_graph-2021-05-31.bin") // By default we're run in RL/lightning
5773 .or_else(|_| File::open("lightning/net_graph-2021-05-31.bin")) // We may be run manually in RL/
5774 .or_else(|_| { // Fall back to guessing based on the binary location
5775 // path is likely something like .../rust-lightning/target/debug/deps/lightning-...
5776 let mut path = std::env::current_exe().unwrap();
5777 path.pop(); // lightning-...
5779 path.pop(); // debug
5780 path.pop(); // target
5781 path.push("lightning");
5782 path.push("net_graph-2021-05-31.bin");
5783 eprintln!("{}", path.to_str().unwrap());
5786 .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");
5787 #[cfg(require_route_graph_test)]
5788 return Ok(res.unwrap());
5789 #[cfg(not(require_route_graph_test))]
5794 #[cfg(all(test, feature = "_bench_unstable", not(feature = "no-std")))]
5797 use bitcoin::hashes::Hash;
5798 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
5799 use chain::transaction::OutPoint;
5800 use chain::keysinterface::{KeysManager,KeysInterface};
5801 use ln::channelmanager::{ChannelCounterparty, ChannelDetails};
5802 use ln::features::{InitFeatures, InvoiceFeatures};
5803 use routing::gossip::NetworkGraph;
5804 use routing::scoring::{FixedPenaltyScorer, ProbabilisticScorer, ProbabilisticScoringParameters};
5805 use util::logger::{Logger, Record};
5806 use util::ser::ReadableArgs;
5810 struct DummyLogger {}
5811 impl Logger for DummyLogger {
5812 fn log(&self, _record: &Record) {}
5815 fn read_network_graph(logger: &DummyLogger) -> NetworkGraph<&DummyLogger> {
5816 let mut d = test_utils::get_route_file().unwrap();
5817 NetworkGraph::read(&mut d, logger).unwrap()
5820 fn payer_pubkey() -> PublicKey {
5821 let secp_ctx = Secp256k1::new();
5822 PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
5826 fn first_hop(node_id: PublicKey) -> ChannelDetails {
5828 channel_id: [0; 32],
5829 counterparty: ChannelCounterparty {
5830 features: InitFeatures::known(),
5832 unspendable_punishment_reserve: 0,
5833 forwarding_info: None,
5834 outbound_htlc_minimum_msat: None,
5835 outbound_htlc_maximum_msat: None,
5837 funding_txo: Some(OutPoint {
5838 txid: bitcoin::Txid::from_slice(&[0; 32]).unwrap(), index: 0
5841 short_channel_id: Some(1),
5842 inbound_scid_alias: None,
5843 outbound_scid_alias: None,
5844 channel_value_satoshis: 10_000_000,
5846 balance_msat: 10_000_000,
5847 outbound_capacity_msat: 10_000_000,
5848 next_outbound_htlc_limit_msat: 10_000_000,
5849 inbound_capacity_msat: 0,
5850 unspendable_punishment_reserve: None,
5851 confirmations_required: None,
5852 force_close_spend_delay: None,
5854 is_channel_ready: true,
5857 inbound_htlc_minimum_msat: None,
5858 inbound_htlc_maximum_msat: None,
5864 fn generate_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5865 let logger = DummyLogger {};
5866 let network_graph = read_network_graph(&logger);
5867 let scorer = FixedPenaltyScorer::with_penalty(0);
5868 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5872 fn generate_mpp_routes_with_zero_penalty_scorer(bench: &mut Bencher) {
5873 let logger = DummyLogger {};
5874 let network_graph = read_network_graph(&logger);
5875 let scorer = FixedPenaltyScorer::with_penalty(0);
5876 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5880 fn generate_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5881 let logger = DummyLogger {};
5882 let network_graph = read_network_graph(&logger);
5883 let params = ProbabilisticScoringParameters::default();
5884 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5885 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::empty());
5889 fn generate_mpp_routes_with_probabilistic_scorer(bench: &mut Bencher) {
5890 let logger = DummyLogger {};
5891 let network_graph = read_network_graph(&logger);
5892 let params = ProbabilisticScoringParameters::default();
5893 let scorer = ProbabilisticScorer::new(params, &network_graph, &logger);
5894 generate_routes(bench, &network_graph, scorer, InvoiceFeatures::known());
5897 fn generate_routes<S: Score>(
5898 bench: &mut Bencher, graph: &NetworkGraph<&DummyLogger>, mut scorer: S,
5899 features: InvoiceFeatures
5901 let nodes = graph.read_only().nodes().clone();
5902 let payer = payer_pubkey();
5903 let keys_manager = KeysManager::new(&[0u8; 32], 42, 42);
5904 let random_seed_bytes = keys_manager.get_secure_random_bytes();
5906 // First, get 100 (source, destination) pairs for which route-getting actually succeeds...
5907 let mut routes = Vec::new();
5908 let mut route_endpoints = Vec::new();
5909 let mut seed: usize = 0xdeadbeef;
5910 'load_endpoints: for _ in 0..150 {
5913 let src = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5915 let dst = PublicKey::from_slice(nodes.keys().skip(seed % nodes.len()).next().unwrap().as_slice()).unwrap();
5916 let params = PaymentParameters::from_node_id(dst).with_features(features.clone());
5917 let first_hop = first_hop(src);
5918 let amt = seed as u64 % 1_000_000;
5919 if let Ok(route) = get_route(&payer, ¶ms, &graph.read_only(), Some(&[&first_hop]), amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes) {
5921 route_endpoints.push((first_hop, params, amt));
5922 continue 'load_endpoints;
5927 // ...and seed the scorer with success and failure data...
5928 for route in routes {
5929 let amount = route.get_total_amount();
5930 if amount < 250_000 {
5931 for path in route.paths {
5932 scorer.payment_path_successful(&path.iter().collect::<Vec<_>>());
5934 } else if amount > 750_000 {
5935 for path in route.paths {
5936 let short_channel_id = path[path.len() / 2].short_channel_id;
5937 scorer.payment_path_failed(&path.iter().collect::<Vec<_>>(), short_channel_id);
5942 // Because we've changed channel scores, its possible we'll take different routes to the
5943 // selected destinations, possibly causing us to fail because, eg, the newly-selected path
5944 // requires a too-high CLTV delta.
5945 route_endpoints.retain(|(first_hop, params, amt)| {
5946 get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok()
5948 route_endpoints.truncate(100);
5949 assert_eq!(route_endpoints.len(), 100);
5951 // ...then benchmark finding paths between the nodes we learned.
5954 let (first_hop, params, amt) = &route_endpoints[idx % route_endpoints.len()];
5955 assert!(get_route(&payer, params, &graph.read_only(), Some(&[first_hop]), *amt, 42, &DummyLogger{}, &scorer, &random_seed_bytes).is_ok());